Causes of anemia in malaria. How to recognize the symptoms of malaria

There is no vaccine against malaria. According to some reports, 40% of people on earth are at risk of contracting malaria. Worldwide, between 350 and 500 million cases of this disease are recorded annually.

Malaria kills over a million lives every year. For children, malaria is the 4th most fatal disease in developing countries. So what is malaria and how can you prevent its spread?

Malaria: prevention and facts. Keep your family safe

You've probably heard about malaria outbreaks in the news or read about it in travel tips. But what is malaria? Are you and your family at risk of infection? How to be safe?

What is malaria?

In developed countries, malaria has been practically eradicated, but people can still become infected, especially when traveling to countries with active foci of malaria. Some experts report that in Europe and the United States, where malaria was considered eradicated, cases of malaria have been re-reported since 2010. Some scientists believe that this is due to global warming and the development of tourism. In Russia, malaria was eliminated during the Soviet era. But in the countries of the former USSR: in Azerbaijan, Tajikistan, Armenia, Turkmenistan, Uzbekistan and Dagestan, residual foci of infection remain, where cases of the disease are recorded annually. In Russia, malaria is mainly imported; from 2000 to 2010, 3998 cases of imported malaria were registered. Also, due to the uncontrolled immigration of people from the countries of the former USSR, natural foci of malaria began to appear in the Caucasus and in the Moscow region.

One cannot be reckless about this deadly disease.

Have healthy person malaria can present with cold-like symptoms. However, for children who do not have access to medical care, malaria can lead to complications, which can make malaria deadly. According to the Center for Disease Control and Prevention, in 2013 there were 198 million cases of malaria worldwide, and about 500,000 people died due to it. The majority of deaths are among children in Africa.

Malaria in Russia and in the World: Where are the foci of malaria?

Malaria can be found almost everywhere, with especially large foci in Asia, Africa, Australia, Central America, the Middle East, the Caribbean and New Zealand. The most deadly strains are found in the Solomon Islands, the Indian subcontinent, Africa, Papua New Guinea and Haiti. Malaria-endemic regions: Sierra Leone, Liberia and Guinea.

If you are traveling to a country where the risk of contracting malaria is high, it is important to be aware of all the possible dangers. If you are going to such a country, you should talk to your doctor and take a course of medication to prevent malaria (which can last up to 2 weeks) before traveling. The Centers for Disease Control and Prevention website has a handy map that shows in which countries the risk of contracting malaria is greatest.

Even if you remain in Russia, cases of malaria infection occur even in our Moscow region and in the Caucasus, since its foci have again begun to appear on the territory of our country, so everyone can face danger. Wherever malaria mosquitoes (genus Anopheles) are found, malaria can also appear there. In Russia, mosquitoes of this genus inhabit almost the entire territory, except for the northernmost regions, however, infection with malaria is unlikely, since only in a small part of the territory of Russia weather conditions are suitable for the development of malaria plasmodium.

Travelers returning from countries where malaria is prevalent can bring malaria home, and local mosquitoes can eventually transmit it to others. In Russia, about 100 cases of malaria are registered annually, and 99% of them are imported.

Another reason people contract malaria is the accidental transport of mosquitoes. Travelers to countries where this dangerous disease is widespread can bring more than just photographs to Russia. Mosquitoes sometimes travel by plane or in luggage, like hitchhiking. They even experience such a trip and can bite passengers, spreading the disease.

How is malaria spread?

Mosquitoes of the genus Anopheles can carry Plasmodium malaria from person to person. The process looks something like this:

This is how malaria usually spreads, but it can also be spread through dirty needles. A mother can pass this disease on to her unborn child. In the past, even blood transfusions have sometimes led to malaria. Despite the fact that transplantation is still considered a risk, donated blood is now thoroughly checked, and this type of transfer is extremely unlikely.

Malaria symptoms

At first, malaria can look like a common cold. Patients may show the following symptoms:

• Chills
• Headache
• Sweating
• Muscle pain
• Diarrhea
• Nausea and vomiting
• General weakness and discomfort

The first symptoms of malaria can appear as early as 6 days after the bite. In some cases, however, symptoms may develop within a month after returning from the malaria outbreak.

If complications develop, malaria can quickly progress from cold-like symptoms to life-threatening symptoms. Complications can include: acute kidney failure, anemia, coma, low blood sugar, breathing and spleen problems, low blood pressure, jaundice, and seizures.

A patient with malaria may develop mild symptoms at first, and then the condition may suddenly become severely worse. It can be terrible pain, trouble breathing, or violent seizures. If this happens, the patient needs emergency medical attention.

If you've been diagnosed with malaria, your doctor will suggest a course of medication. Doctors will monitor your condition and the course of the disease to prevent complications from developing. Your doctor will advise you on how not to pass malaria to others, such as donating blood.

One of the problems with diagnosing malaria is that it has very nonspecific first symptoms. Anyone with a fever or chills can assume they have a simple cold. They would rather decide that "it will pass by itself" and will not go to the doctor. Even doctors may not immediately suspect malaria, especially in Russia. Our cases of this disease are quite rare, so the doctor may not order an analysis for malaria, when the patient only has symptoms similar to a cold.

Malaria is easy to overlook or confused with another disease, which means that patients may not receive timely treatment and spread malaria further. To help doctors, be on guard and be aware of the symptoms of malaria. If you have traveled to a country where malaria is common and then you develop a fever, see your doctor right away and tell them where you have been.

Malaria treatment

Once malaria has been diagnosed, it is important to get the right therapy right away. Without treatment, the patient's condition will quickly deteriorate. If complications develop, malaria can even lead to death. Children, the elderly and those with serious illnesses are at increased risk of not coping with malaria on their own.

If you have been diagnosed with malaria, you are likely to be prescribed one of the following medicines:

• Chloroquine
• Quinine sulfate
• Atovacuon and proguanil
• Hydroxychloroquine
• Mefloquine
• Quinine
• Quinidine
• Dixicycline
• Clindamycin

There is no vaccine for this disease, although scientists are working on its invention. But scientists agree on one thing: to prevent malaria, you need to avoid mosquito bites. To protect your family from malaria, you can do the following:

If you have tried your best, but you are bitten by a mosquito, and after that you have a cold-like symptoms, be sure to see a doctor right away. If you have malaria without treatment, you can contribute to the spread of the disease and your health could be seriously affected.

Stop mosquitoes - the best malaria prevention

Mosquitoes are enemy number one when it comes to malaria. When experts are asked, "How to prevent contracting malaria?" - the majority answer that the best solution is to reduce the risk of mosquito bites. Unfortunately, mosquitoes are everywhere.

If you want to reduce your risk of mosquito bites, here are some tips that may help:

Remove standing water near your home. Rain barrels, ponds, puddles, swamps, and any object that can collect water can be a great breeding ground for mosquitoes. Removing standing water or protecting yourself from such places will significantly reduce the number of mosquitoes and their bites.

Trim plants and grass in the area well. Shady areas with moist soil attract mosquitoes, as does tall grass. Remember to mow your lawn and trees so that no mosquito can hide in your yard.

Use mosquito control methods. Use electric traps, repellents, or citronella candles.

Add smoke. While relaxing outdoors, it is better to light a fire - most insects do not like smoke.

Use Mosquito Magnet mosquito traps. These traps reduce the mosquito population near your home. Unlike pesticides, Mosquito Magnet exterminators are a non-toxic and long lasting solution to mosquito problems.

In addition to the fact that mosquitoes can transmit malaria, swarming bloodsuckers are annoying and can transmit other diseases. Enjoy the summer and protect your family by reducing mosquito populations near your home.

Mosquito Magnet traps are one of the rare long-term solutions that reduce mosquito populations in your yard. These shredders convert propane to carbon dioxide (CO2). Traps mimic the humidity and temperature of human respiration, which attracts female mosquitoes. As soon as the insect flies up to the trap, it is sucked into the net inside the trap, where it dries up and dies. Since it is the females that fall into the trap, the mosquito population will gradually decline.

You will enjoy fewer mosquito bites and fewer itchy spots and a lower risk of contracting vector-borne diseases.

Protect your family, pets and guests from mosquito-borne diseases with the Mosquito Magnet trap - a long-lasting, scientifically proven solution.

Part 1

Identifying symptoms of malaria

Severe chills. Another major symptom of malaria is severe, shaking chills that alternate with periods of sweating. A tremendous chill is characteristic of many other infectious diseases, but in malaria it is usually more pronounced and intense. The chills are so intense that they cause chattering teeth and even interfere with sleep. If the chills are particularly severe, it can be confused with a seizure. Typically, malaria chills are not relieved by wrapping in a blanket or warm clothing.

Vomiting and diarrhea. Another common secondary symptom of malaria is vomiting and diarrhea, which occur many times throughout the day. They often accompany each other, which reminds initial symptoms food poisoningas well as some bacterial infections. The main difference is that with food poisoning, vomiting and diarrhea go away after a few days, while with malaria, they can last for several weeks (depending on treatment).

Recognize late symptoms. If, after the appearance of primary and secondary symptoms, the patient did not seek medical help and did not receive appropriate treatment, which is not always available in developing countries, then the disease progresses and leads to significant damage to the body. At the same time, late symptoms of malaria appear and the risk of complications and death increases significantly.

• Confusion, multiple convulsions, coma, and neurologic disorders are indicative of swelling and brain damage.
• Severe anemia, abnormal bleeding, difficulty breathing deeply, and respiratory failure indicate severe blood poisoning and infection in the lungs.
• Jaundice (yellowish skin and eyes) indicates liver damage and dysfunction.
• Renal failure
• Liver failure.
• Shock (very low blood pressure).
• Enlarged spleen.

Part 2

Risk factors

1. Be very careful when visiting undeveloped tropical regions. Those who live or travel to countries where the disease is prevalent are at greatest risk of contracting malaria. The risk is especially high when visiting poor and underdeveloped tropical countries because they do not have the money to control mosquitoes and other preventive measures against malaria.

   Take preventive measures when traveling to high-risk areas. To protect yourself from mosquito bites Anophelesdo not stay outside for too long; wear long-sleeved shirts, pants and cover as much of the skin as possible with clothing; Apply an insect repellent containing diethyltoluamide (N, N-diethylmethylbenzamide) or picaridin; spend time in rooms with windows protected by mosquito nets or air-conditioned; Sleep on a bed with an insecticide-treated mosquito net (such as permethrin). Also, talk to your doctor about taking an antimalarial drug.

• Malaria should be viewed as a deadly disease. If you suspect you have malaria, see your doctor immediately.
• The symptoms of malaria are similar to those of many other diseases. It is very important to inform your doctor that you have recently returned from an area where there is a risk of malaria, otherwise he may not initially think of it as a possible cause of the symptoms and not make a diagnosis in time.

Malaria is one of the most dangerous human diseases. Plasmodium malaria is transmitted to humans through the bites of infected Anopheles mosquitoes. Plasmodium vivax causes three-day malaria, Plasmodium malariae causes four-day malaria, Plasmodium ovale causes three-day-like malaria, Plasmodium falciparum causes tropical malaria... Each form of the disease is different, but symptoms of malaria such as attacks of fever, anemia, and hepatosplenomegaly are common to all.

The life cycle of the development of the malarial plasmodium consists of 2 stages occurring in the body of a mosquito and the human body. In the human body, clinical manifestations of the disease are associated only with erythrocytic schizogony. Malaria is a polycyclic infection. During the course of the disease, an incubation period (primary and secondary), a period of primary acute manifestations, a secondary latency and a period of relapses are distinguished. If the infection occurred naturally (through), they speak of a sporozoite infection. If the disease has developed with the introduction into the human body of donor blood containing plasmodium or as a result of vaccination, they speak of schizont malaria.

Figure: 1. Anopheles mosquito - a carrier of malaria plasmodia.

Figure: 2. Plasmodium malaria - the cause of malaria.

Incubation period

When a mosquito bites, sporozoites penetrate the bloodstream, where they move freely for 10-30 minutes, and then settle in hepatocytes (liver cells). Part of the sporozoites Pl. ovale and Pl. vivax go into hibernation, another part of them and Pl. falciparum and Pl. malariae immediately begin hepatic (exoerythrocytic) schizogony, during which 10 to 50 thousand hepatic merozoites are formed from 1 sporozoite. Having destroyed the liver cells, the merozoites are released into the blood. The whole process takes from 1 to 6 weeks. This ends the incubation period of malaria and begins the period of erythrocytic schizogony - the period of clinical manifestations.

For different types pathogens have their own duration of the incubation period of malaria:

• With Plasmodium vivax, the short incubation period is 10 - 21 days, the long incubation period is 8 - 14 months.
• With Plasmodium malariae - 25 - 42 days (in some cases more).
• With Plasmodium falciparum - 7-16 days.
• With Plasmodium ovale - from 11 to 16 days.

The duration of the incubation period for malaria is increased with inadequate chemotherapy.

Before an attack of malaria at the end of the incubation period with Plasmodium vivax and Plasmodium falciparum, a prodromal period is recorded: symptoms of intoxication and asthenia, headache, muscle and joint pain, appear, general weakness, weakness, chilling.

Figure: 3. Malaria is common in more than 100 countries in Africa, Asia and South America.

Signs and symptoms of malaria during a febrile attack

The pathogenesis of fever in malaria

Being in erythrocytes, plasmodia assimilate hemoglobin, but not completely. Its remains are converted into dark brown pigment grains, which accumulate in the cytoplasm of young schizonts.

When the erythrocyte ruptures, foreign proteins, hemoglobin, malaria pigment, potassium salts, and the remnants of erythrocytes penetrate into the blood along with merozoites. They are foreign to the body. Acting on the center of thermoregulation, these substances cause a pyrogenic reaction.

Malaria in a greater number of cases occurs with characteristic febrile attacks. Rarely, the disease proceeds with a constant fever lasting from 6 to 8 days, and only then febrile paroxysms appear.

Figure: 4. Annually, up to 30 thousand cases of "imported" malaria are registered, 3 thousand of which end in death. In 2016, 100 cases of imported malaria were registered in the Russian Federation.

Development of an attack of fever

1. In the initial period of fever paroxysm the patient develops chills lasting from 30 minutes to 2 - 3 hours, often strong, the skin and mucous membranes become pale in color, goose bumps appear. The patient freezes and wraps himself up with a blanket over his head.

Figure: 5. The rise in temperature in infectious diseases is always accompanied by chills.

1. Febrile attack more often occurs around 11 am. The body temperature rises to 40 ° C or more, quickly, nausea, vomiting and dizziness occur. In severe malaria, seizures, delirium, and confusion occur. The patient is agitated, the skin is hyperemic, hot and dry to the touch, and herpes sores often appear on the lips. The tongue is coated with a brownish coating. Tachycardia, shortness of breath and urinary retention are noted, blood pressure drops. The patient becomes hot. He is thirsty.

Figure: 6. An attack of malaria in a woman (India).

1. After 6 - 8 hours, and in tropical malaria by the end of the first day, body temperature decreases. The patient develops profuse sweating. Symptoms of intoxication gradually disappear. The patient calms down and falls asleep. After half a day, the patient's condition becomes satisfactory.

Figure: 7. The decrease in temperature is accompanied by profuse sweating.

1. Repeated bouts of fever occurafter 2 days with 3-day, oval and tropical malaria or after 3 days with 4-day malaria.

1. Secondary latency comes after 10 - 12 attacks of fever.
2. With inadequate treatment weeks (sometimes months) later, there are near (up to 3 months) or distant (6 - 9 months) relapses.

After several attacks, the liver and spleen enlarge in patients, anemia develops, the cardiovascular and nervous systems suffer, symptoms of nephritis appear, and hematopoiesis suffers. After the cessation of febrile attacks, anemia and hepatosplenomegaly persist for quite a long time.

Figure: 8. Temperature curve for malaria.

Signs and symptoms of malaria with internal organ damage

Causes of damage to internal organs

With insufficient treatment, pathological changes are found in various organs of a patient with malaria, the cause of which is:

• pathological substances circulating in the blood, leading to hyperplasia of the lymphoid and reticuloendothelial elements of the spleen and liver,
• sensitization of the body by foreign proteins, often accompanied by autoimmunopathological reactions of the hyperergic type,
• breakdown of red blood cells leading to damage internal organs, the development of anemia and thrombocytopenia, impaired blood circulation in the capillaries and the development of intravascular thrombus formation,
• violation of water and electrolyte balance.

Plasmodium, being in erythrocytes, absorb hemoglobin, but not completely assimilate it. As a result, its remnants gradually accumulate in the cytoplasm of young schizonts. During the formation of merozoites, the pigment enters the bloodstream and is then captured by macrophages of the liver, lymph nodes, spleen and bone marrow, which acquire a characteristic smoky or brown color. With a prolonged course, the pigment in the interstitial tissue forms massive clusters. Its processing and disposal is slow. The specific coloration of the internal organs remains long time after healing.

Foreign substances circulating in the blood irritate the reticular cells of the spleen, liver, cause their hyperplasia, and with a long course - proliferation connective tissue... The increased blood supply to these organs leads to their enlargement and soreness.

Lack of appetite, nausea and a feeling of fullness in the epigastric region, often diarrhea are the main signs of liver damage in malaria. The liver and spleen gradually begin to enlarge. By the 12th day, yellowness of the skin and sclera appears.

The liver and spleen in malaria are enlarged and dense. The spleen may rupture with minor injury. Its weight often exceeds 1 kg, sometimes the weight reaches 5 - 6 kg or more.

Figure: 10. A liver preparation affected by plasmodia.

Figure: 11. Enlargement of the liver and spleen in patients with malaria.

Bone marrow damage

Malaria anemia

The breakdown of erythrocytes during the period of erythrocytic schizogony, increased phagocytosis and hemolysis due to the formation of autoantibodies are the main causes of anemia in malaria. The type of plasmodium influences the degree of anemia. Iron deficiency and folic acid in residents of a number of developing countries in Africa, the disease is aggravated.

Gametocytes of plasmodia of 3-day, 4-day malaria and oval malaria develop in erythrocytes of peripheral capillaries within 2 - 3 days and die after maturation in a few hours, therefore anemia in these types of malaria often reaches a significant degree. Blood regeneration slows down significantly during three-day malaria, since plasmodia settle mainly in young erythrocytes - reticulocytes. In addition, Plasmodium vivax induces ineffective bone marrow erythropoiesis. Malaria anemia is exacerbated by the destruction of healthy (uninfected) red blood cells.

The degree of anemia is related to the size of the spleen. The spleen is the only blood filtering organ in the human body. Its increase - distinctive feature malaria infections. In case of damage to erythrocytes of a benign nature in the spleen, the work of extramedullary hematopoiesis starts, which compensates for the losses.

Typical changes in the blood in malaria appear from 6 to 8 days of the disease. And by the 12th day, hypochromic anemia, significant leukopenia, thrombocytopenia are recorded, and ESR is significantly accelerated.

Figure: 12. Erythrocytes when infected with Plasmodium vivax and Plasmodium ovale are deformed. When infected with Plasmodium malariae and Plasmodium falciparum, the shape and size of erythrocytes does not change.

Figure: 13. The destruction of erythrocytes during the release of merozoites into the blood is one of the causes of anemia in the disease.

Signs and symptoms of malaria with heart disease

Heart function is affected by toxic substances and anemia. Expansion of the borders of the heart to the left, muffled tones at the apex and a slight systolic murmur at the apex are the first signs of organ damage in malaria. Long-term malaria has a negative effect on the functioning of the cardiovascular system. The patient begins to develop swelling on the feet and legs.

Signs and symptoms of malaria when the nervous system is affected

Malaria affects the autonomic nervous system. Irritability, headache, fatigue are the main symptoms of malaria with damage to the nervous system in long-term ill people.

Figure: 14. Damage to the brain in malaria. Multiple hemorrhages are visible in the brain tissue.

Relapses of malaria

The reason for the early relapses that occur during the first 3 months after the alleged recovery is the preserved schizonts, which, when the immunity is weakened, actively multiply again.

The course of relapses is usually benign. General toxic syndrome is expressed moderately. Malarial paroxysms proceed rhythmically. Anemia, enlarged spleen, and liver are the main signs of recurrent malaria.

The duration of the disease caused by Plasmodium vivax lasts 1.5 - 3 years, Plasmodium ovale - from 1 to 4 years.

Figure: 15. Children with malaria.

Complications of malaria

In malaria, complications arise that are closely related to the pathogenesis of the disease. These include anemia in severe form, persistent enlargement of the spleen and its cirrhosis, cirrhosis and melanosis of the liver, nephrosonephritis, encephalopathy with development mental disorders and hemoglobinuric fever.

When acute diffuse nephrosonephritis patients develop edema, protein and erythrocytes in the urine, in some cases arterial hypertension develops. Symptoms that are affected by adequate treatment and diet.

When malarial hepatitisyellowness of the sclera and skin appears, the liver increases, palpation reveals its soreness, bilirubin in the blood builds up, functional liver tests are perverted.

Available ruptured spleen with minor injury.

Hemoglobinuric fever is the most severe complication of tropical malaria, rarely occurs in other types of the disease. With the disease, acute hemolysis of erythrocytes develops, a flood of blood hemoglobin and its excretion in urine, which occurs under the influence medicinal product quinine. The patient develops an icteric color of the sclera and skin, enlarges the liver and spleen.

Acute pulmonary edema develops in tropical malaria. The trigger is an increase in vascular permeability as a result of exposure to toxins. The problem is aggravated by the increased introduction of fluid into the patient's body.

Hypoglycemia develops mainly in tropical malaria. Its cause is a violation of glucogenesis in the liver, an increase in glucose consumption by plasmodia and stimulation of insulin secretion by the pancreas. With a disease, a large amount of lactic acid accumulates in the patient's tissues. The developed acidosis is often the cause of death.

Timely detection and adequate treatment of malaria always ends with recovery. Tropical malaria is always fatal if detected late and inadequately treated. The other three types of malaria are benign infections.

Figure: 17. Yellowness of the sclera and skin indicates liver damage

Malaria in pregnant women

Malaria adversely affects pregnancy and its outcome. It can cause abortion, miscarriage and premature birth. Delay in fetal development and death is often noted. Malaria is often the cause of eclampsia in pregnancy and death. Pregnant women living in malaria-endemic foci are the most threatened contingent. Late diagnosis and inadequate treatment quickly lead to the development of "malignant malaria". It is especially dangerous in pregnant women to develop hypoglycemia, which is often the cause of death.

Figure: 18. Placenta infected with malaria plasmoids.

Malaria in children

The most vulnerable is the age of children from 6 months to 4 - 5 years. Malaria is especially dangerous for young children.

In malaria-endemic regions, the disease in children is one of the causes of high mortality. Children under 6 months of age who are born to immune mothers do not develop malaria.

Types of malaria in children

Malaria in children is congenital and acquired.

Malaria in children often takes on a fulminant course. Severe anemia and cerebral disease may develop within a few days. Malaria in children often occurs in a peculiar way:

• the skin is pale, often with an earthy tinge, yellowness and waxy appearance are kept, despite treatment, for a long time;
• malarial paroxysms (attacks of fever) are often absent;
• symptoms such as cramps, diarrhea, regurgitation, vomiting, and abdominal pain come to the fore;
• with attacks of malaria, chills are often absent at the beginning, and sweating is often absent at the end of an attack of fever;
• a rash in the form of hemorrhages and spotty elements often appears on the skin;
• anemia builds up quickly;
• in congenital malaria, the spleen is significantly enlarged, the liver to a lesser extent.

Symptoms of Malaria in Older Children

In older children, the disease proceeds as in adults. In the interictal period, the condition of the children remains satisfactory. The fulminant form of three-day malaria is rare, and malaria coma is extremely rare.

Differential diagnosis

Malaria in children should be distinguished from hemolytic disease of the newborn, sepsis, septic endocarditis, miliary tuberculosis, pyelonephritis, hemolytic anemia, typhus, brucellosis, food poisoning, leishmaniasis in children living in the tropics.

Figure: 19. Up to 90% of malaria cases and deaths occur in countries on the African continent.

Figure: 20. About 1 million children die each year from malaria.

Malaria is a common cause of death from travel-acquired infections in the UK. Malaria is not ruled out in all febrile patients returning from malaria-endemic areas.

Pathogenesis:

• in all forms, the pathogen enters the body at the sporozoite stage;
• sporozoites are brought into hepatocytes - tissue schizogony develops here, merozoites are formed;
• with the decay of hepatocytes, merozoites develop in erythrocytes - the pathogen multiplies in erythrocytes, which leads to rupture of erythrocytes - the cycle lasts 48 hours, and in tropical - 72 hours;
• the onset of an attack indicates a rupture of erythrocytes;
• during schizogony, gamonts (male and female) are formed;
• gamonts.

Epidemiology of malaria

Transmission mechanism: transmissible, there may be a parenteral transmission route - through blood transfusion or through instruments, objects contaminated with blood. There may be an infection during childbirth.

Malaria causes

The causative agent of malaria

Plasmodium falciparum is the causative agent of the most severe and potentially fatal or malignant form of malaria.

P. vivax, P. ovale, and P. malariae can cause chronic recurrent disease, but are not life-threatening.

There are no reliable clinical criteriato distinguish each type of infection. Morphology different types pathogens when examined in a blood smear are different, but this requires expert interpretation. In order to differentiate between P. falciparum and P. vivax, a reliable test for the detection of malaria antigen in the blood can be applied. Infection with several types of pathogen is possible. When in doubt about the type of pathogen, therapy should be directed against P. falciparum.

Malaria mosquito

It is generally accepted that malaria mosquitoes for the most part live in hot, humid countries, and in Russia there are no suitable conditions for them. However, this opinion is wrong. In fact, only the Far North and part of Eastern Siberia have temperatures so low in winter as to impede the survival of the mosquito family.

The malaria mosquito has its own name - anopheles. This is just one genus of mosquitoes from their numerous family, but there are 9 varieties of them in Russia. No other mosquitoes are capable of transferring Plasmodium malaria to humans. In appearance, it is almost impossible to distinguish anopheles from other brethren. Its biological features (long hind legs, black dots on the wings, a special position of the body during a bite, etc.) are known only to biologists, and even then specializing in the study of dipterans.

An ordinary person does not particularly examine the mosquito in detail, but tries to swat it as quickly as possible.

Fortunately, in order for a person to be infected by a malaria mosquito, an essential condition is necessary: \u200b\u200bthe presence of a person with malaria, and in Russia it has been practically eliminated and only variants of an imported infection are possible. However, in our time, the wide migration of different strata of the population cannot exclude such a possibility. In addition, an infectious mosquito can be accidentally brought into an uninfected area. Therefore, local outbreaks of malaria are quite possible and occur periodically. Cases of this disease, for example, are constantly recorded in the Astrakhan region.

If Anopheles does not get drunk with blood contaminated with malarial plasmodium, he will not be able to become a carrier of malaria, but will remain an ordinary mosquito for everyone. His bite is as safe as the bites of his fellow tribesmen.

Why does malaria cause fever?

Feverish chills in malaria are due to a pathology in the heat exchange system. Plasmodium toxins, and most importantly, their "fragments" are a foreign protein, therefore, they change the specific reactivity of the body and destabilize the work of the heat regulation center in the body.

The minimum amount of a pathogen that can cause symptoms of malaria is called the pyrogenic threshold. This threshold depends on the level of human immunity and the individual characteristics of the organism.

As a result of a temperature reaction, blood circulation worsens, and this condition leads to a malnutrition of tissues, a change in metabolism, as well as stagnation of a part of the blood and the development of an inflammatory process in these areas.

The destruction of red blood cells by malaria leads to hemolytic anemia. It is this process that causes lethargy, weakness, shortness of breath, dizziness, and a tendency to faint.

A foreign protein leads to an increase in tissue sensitivity (sensitization of the body) and the development of autoimmune pathology.

Touches for a portrait of malaria

Only at the end of the last century, scientists discovered that dormant forms of some species of plasmodium malaria can exist (persist) in the liver for a long time. They have the ability to wake up, release into the bloodstream and cause a relapse of malaria after many months and even years. In the world every year millions of people die from malaria, several times more than from AIDS. Over the past decade, malaria, traditionally ranked third in mortality among infectious diseases, has become the leader in this indicator.

Due to the increased greenhouse effect and climate warming, areas favorable for the breeding of malaria mosquitoes are gradually moving north. A person who has had malaria cannot be a donor for 3 years after the disease. In the future, when donating blood, it is necessary to warn doctors that the person has suffered from malaria. Have malaria mosquitoes are attached to stagnant water. They are unable to fly more than 8 km, so they are not in the mountains, deserts and steppes.

Symptoms and signs of malaria

The incubation period for a three-day period is 7-21 days, for a four-day period - 14-42 days, for a tropical one - 6-16 days, for an oval - 7-21 days.

Sharp start. Sometimes the prodromal period: malaise, aches, pain in the lower back, legs, back.

Fever attacks last up to 12 hours. Change of chills - heat phase - sweat phase with a frequency of 48-72 hours. In the interictal period, there is an improvement in well-being. After three attacks, the liver and spleen are palpated. Hemolytic anemia, increased bilirubin. The mucous membranes and skin are pale yellow. Fever is intermittent. Then the skin is pale icteric staining. In severe condition, there may be hemorrhages. During the chill, the skin is pale, cold, during the heat - dry, hot, the face is hyperemic. With a decrease in temperature, profuse sweating. Shortness of breath, impaired pulmonary ventilation, blood circulation are possible. With paroxysms: nausea, vomiting, flatulence, pain in the epigastric region. After three attacks, hepatosplenomegaly develops. In the tropical form - dyspeptic symptoms, decreased urine output. With nephritis - increased blood pressure, edema, albuminuria, may be acute renal failure. In the tropical form, hemoglobinuric fever may occur: decreased urine output, black or red urine. With paroxysms: headache, delirium, anxiety, agitation, sometimes manifestation of a manic or depressive paranoid state. The pupillary reflex fades away, the patients do not react to external stimulation, their eyes are closed, motionless. There may be meningeal symptoms and pathological reflexes, there may be excitement. Coma is possible: lethargy, deep sleep.

High fever and chills are replaced by sweating. Alternating daytime fever has been described, but rarely present.

Headache - Extreme frequent symptom... With concomitant impairment of consciousness or behavior, as well as with convulsions, hypoglycemia must be excluded. The cerebral form of malaria is manifested by coma. Retinal hemorrhage, drowsiness and others neurological symptoms can be early manifestations of malaria-related brain damage that can progress further.

Abdominal symptoms: anorexia, pain, vomiting, and diarrhea.

An attack of malaria usually lasts 6-10 hours or longer. In the interictal period, severe weakness is noted. After 3-4 attacks of malarial fever, the liver and spleen enlarge, sometimes myocardial dystrophy, acute transient nephritis and other pathological changes in organs develop. In the midst of seizures, febrile delirium, vegetative neuroses and psychosis are possible.

Eye symptoms.Pathological changes are associated with intoxication and developed anemia (vascular walls are damaged and multiple thrombosis of the smallest vessels are formed). This is manifested already at the first attack of fever by punctate and more extensive hemorrhages against the background of a hyperemic conjunctiva. In patients with three days of malaria there is an activation of herpesvirus infection, which is manifested by the appearance of treelike keratitis. In the fundus, a spasm of retinal vessels with impaired blood microcirculation and the phenomenon of endarteritis, retinal ischemia with preretinal and retinal hemorrhages is revealed. These changes are found in the central regions of the fundus.

In severe malaria with a coma, the optic nerves are involved in the pathological process in the form of bilateral optic neuritis.

In the chronic course of malaria, accommodation paralysis, blepharitis, pigmentation and conjunctival xerosis, corneal pigmentation and keratitis, iridocyclitis, choroiditis, alternating strabismus develop.

Diagnostics based on:

• passport data (place of residence, profession);
• complaints - fever, its characteristics, frequency of attacks, the sequence of the appearance of clinical signs;
• medical history, life - acute onset, past diseases;
• epidemic history - stay in areas with tropical and subtropical climates, blood transfusion;
• clinical data;
• OAK - anemia, leukopenia, neutropenia, coagulogram, hemoglobin;
• microscopy;
• OAM - proteinuria, cylindruria, albuminuria;
• serological studies: RSIF, enzyme-linked immunosorbent assay (ELISA), is used when examining donors;
• studies of the acid-base state;
• biochemical indicators.

Differential diagnosis - with typhoid fever, ARVI, pneumonia, Q fever, relapsing fever, pyelitis, pyelonephritis, perineal abscess, cholecystitis, cholangitis, cholelithiasis, sepsis, hemolytic jaundice, leukemia, influenza virus, OI arbovirus diseases.

Malaria: laboratory and instrumental research methods

General blood analysis. Anemia, non-immune hemolysis, leukopenia, and thrombocytopenia suggest P. falciparum.

Glucose. Hypoglycemia can be observed with P. falciparum infection or intravenous administration quinine, especially during pregnancy
Urea, creatinine, functional tests liver Acute renal failure and hemoglobinuria can occur in severe P. falciparum malaria.

Bacteriological blood test. Other infections such as gram-negative sepsis can accompany malaria.

Computed tomography of the brain and lumbar puncture. These studies may be required if cerebral malaria is suspected /

Arterial blood gases. Metabolic acidosis indicates severe malaria.

Malaria in children

All children with malaria can be divided into two large groups: those who get sick for the first time, and those who have recurred malaria. The first group includes, as a rule, toddlers, in the second group - children over 10 years old. In the first group, malaria is much more severe, while the second group is at least slightly, but protected, albeit weak, but immunity.

In general, malaria in children is much more serious and aggressive than in adults. The main symptoms - attacks of fever - are the same: with 3-day malaria - every two days for 5-6 hours in a row, with 4-day malaria - every 3 days for 12 or more hours. Headache is also characteristic, heat, excitement, pain in joints and muscles, thirst and, of course, attacks of severe chills, from which neither hot-water bottles nor a warm bed can save you. The attack ends with profuse sweating, weakness and drowsiness. Between attacks, the temperature is kept at normal levels, general state satisfactory.

The clinical appearance of symptoms is observed on the 8-15th day after infection, but may appear after several months. Small children who do not know how to explain what is happening to them become whiny, irritable, their appetite decreases, their sleep is disturbed, their limbs get cold, their skin turns pale. The decrease in temperature is accompanied by some sweating of the head and neck. In the initial period, the temperature in babies in some cases may be about normal, in others it starts sharply with an increase to 40 "C. There are practically no chills in infants, instead of them convulsions are observed.

With the development of the disease, the child weakens and grows thin due to the development of anemia caused by the destruction of red blood cells. Moreover, the change in the blood formula occurs very quickly.

Malaria in pregnant women

It is very undesirable for pregnant women to get sick with this ailment, since it is fraught with the loss of the child.

Spontaneous abortion (miscarriages and stillborn babies) in malaria occurs 3 times more often than usual. This is explained by the fact that the malarial plasmodium is able to overcome the placental barrier. The child dies in utero from intoxication, hypoglycemia, anemia.

If the mother is infected late in life, the baby may be born alive, but still sick and low in weight. They have jaundice, fever, epileptic seizures, because the same unfavorable changes (destruction of red blood cells) occur in the child's body as in an adult.

When early term pregnancy and severe malaria, doctors often recommend termination of pregnancy, because the earlier the infection occurs, the worse for the fetus. In general, the outcome of the disease for the fetus depends not only on the timing of infection, but also on the state of health of the mother and the time of treatment started.

A feature of this disease in pregnant women is its severe atypical course due to anemia and an increased risk of malignant forms, fraught with serious complications in the liver and the appearance of a malarial coma. Therefore, pregnant women should not travel to areas where they can get bitten by an anopheles mosquito. And if such a trip cannot be avoided, it is necessary to undergo a course of preventive treatment.

With the standard course of the disease, pregnant women are treated according to a similar scheme as for ordinary patients, since most drugs used for malaria are considered fairly safe. In any case, the prevailing opinion among doctors is that the therapeutic results are more significant than the possible negative drug effect. No matter how much there is discussion about this, the risk of developing intrauterine malaria in a child exceeds the level of danger of exposure to antimalarial drugs.

Malaria treatment

When P. vivax is resistant to chloroquine, mefloquine or quinine are used.

Quinine is also used to treat chloroquine-resistant cases.

For oligoanuria, azotemia and hyperkalemia, plasma ultrafiltration or hemodialysis is prescribed.

Hignin inside, 600 mg every 8 hours, if signs of quinine overdose appear (nausea, tinnitus, deafness), the interval is increased to 12 hours. once 3 tablets of Fansidar (pyrimethamine and sulfadoxine) or if the pathogen is resistant to Fansidar (especially often observed in East Africa) or if you are allergic to Fansidar, doxycycline is prescribed.

Complicated or severe P. falciparum malaria in adults

Mefloquine can also be effective, but resistance to it is more common, so it is recommended that you consult with a malaria specialist regarding the choice of drug, including depending on the country in which the patient contracted malaria.

Antimalarial immunity

Despite the high infectiousness of malarial infection, not all people get sick with this disease, since some have innate immunity. Others develop acquired active or passive immunity.

Active immunity occurs after an illness. It is associated with the restructuring of the body, the production of specific antibodies, and an increase in the level of immunoglobulin. However, this immunity develops slowly, only after several months of repeated attacks, moreover, it is unstable and short-lived. Passive immunity is acquired by newborns from a mother with antimalarial immunity, but it only lasts for about three months.

The pathogenesis of hemorrhagic generalized capillarotoxicosis is caused by obliteration (blockage) of blood vessels, malnutrition of nerve cells and brain tissues, followed by necrosis of the medulla and edema of the meninges.

In addition to encephalitis itself, other disorders in nervous systemcausing neuralgia, neuritis, radiculitis, polyradiculoeuritis, serous meningitis, etc.

With malarial encephalitis, cerebral disorders are observed in the form of impaired speech and coordination of movements, dizziness, headache, nausea, vomiting, etc., up to delirium and seizures similar to epileptic ones. Mental disorders can lead to disability. True, malaria psychosis practically does not occur in primary malaria, they are characteristic of repeated attacks.

Malarial encephalitis is treated in the intensive care units of clinics, where detoxification, hormone therapy, neuroprotective agents and other drugs are used.

When successful treatment primary disease signs of encephalitis also disappear almost safely.

Specific and non-specific protection methods

If you are going to travel to an epidemically unfavorable region for malaria, you should take preventive measures, that is, antimalarial drugs, and then avoid mosquito bites by using means of protection against bloodsucking.

If the trip does not take more than a month, a few days before departure and throughout the trip, you should drink 1 tablet of doxycycline daily. If you have to live more in an unfavorable place, it is better to stock up on lariam. This drug should be started a week before departure and then during the entire period, 1 tablet per week.

Most people know how to escape mosquito bites. First of all, repellents are used: sprays, ointments, lotions, and they must be applied not only to the skin, but also to clothes, shoes, backpacks, bags, etc.

Indoors, fumigators and mosquito nets on windows help fight insects.

If you are going to spend the night outdoors, you should use mosquito nets, which are thrown over the bed or over the sleeping bag.

Prevention of malaria

If getting rid of mosquitoes is very difficult, then in epidemically unfavorable areas, the population is advised to protect themselves from bloodsucking individuals individually: wear appropriate clothing, use deterrent creams and sprays, cover your face with a mosquito net.

You can protect yourself from the development of plasmodium inside the body by taking preventive preventive measures. There are special drugs that are used if you are going to travel to areas dangerous for the development of malaria. The course of their intake begins 2 weeks before and a month after the epidemically unfavorable place.

Usually, for prophylaxis, the same means are used as for treatment, however, other, smaller doses and a different regimen for their intake are used. In the future, doctors take into account the fact that if some drug was used for prophylaxis and did not give an effect (that is, the person still fell ill), then it is already useless to prescribe this medication as drug... Combinations with artemisinin and quinine are not used for prophylaxis.

There is no vaccine yet to prevent malaria, although there is ongoing active work to develop it, and there are already some promising intermediate results.

It is accompanied by fever, chills, an increase in the size of the spleen and liver, anemia. A characteristic feature of this protozoal invasion is cyclical clinical course, i.e. periods of improvement in health are replaced by periods of sharp deterioration with a high rise in temperature.

The disease is most common in countries with hot climates. These are South America, Asia and Africa. According to the World Health Organization, malaria is a serious medical problem in 82 countries where deaths from this infection are very high.

The relevance of malaria for a Russian person is due to the possibility of infection during tourist trips. Often, the first symptoms appear already upon arrival at home, when a person's temperature rises.

Without fail, when this symptom appears, you should inform the doctor about your trip, because this will make it easier to establish the correct diagnosis and save time.

Causes, clinic of the disease

The causative agent of malaria is the malaria plasmodium. It belongs to the class of protozoa. Causal agents can be 4 types of plasmodia (although there are more than 60 species of them in nature):

• P. malariae - causes malaria with a 4-day cycle;
• P. vivax - causes malaria with a 3-day cycle;
• P. falciparum - causes tropical malaria;
• R. Ovale - causes an oval-shaped three-day malaria.

The life cycle of malaria plasmodia includes a sequential change of several stages. In this case, there is a change of owners. At the stage of schizogony, pathogens are in the human body. This is the stage of asexual development, it is replaced by the stage of sporogony.

It is characterized by sexual development and occurs in the body of the female mosquito, which is the carrier of the infection. Causal mosquitoes belong to the genus Anopheles.

The penetration of malaria plasmodia into the human body can occur at different stages in different ways:

1. When bitten by a mosquito, infection occurs at the spore stage. The penetrated plasmodia end up in the liver after 15-45 minutes, where their intensive reproduction begins.
2. The penetration of the plasmodia of the erythrocyte cycle at the schizont stage occurs directly into the blood, bypassing the liver. This pathway is realized when donated blood is introduced or when using non-sterile syringes that can be infected with plasmodia. At this stage of development, it penetrates from mother to child in utero ( vertical path infection). This is the danger of malaria for pregnant women.

In typical cases, the division of plasmodia that have entered the body through a mosquito bite occurs in the liver. Their number is increasing many times over. At this time, there are no clinical manifestations (incubation period).

The duration of this stage is different depending on the type of pathogen. It is minimal in P. falciparum (from 6 to 8 days) and maximum in P. malariae (14-16 days).

The characteristic symptoms of malaria are described by the famous triad:

• paroxysmal (by the type of crises) increase in temperature, repeated at regular intervals (3 or 4 days);
• enlargement of the liver and spleen (hepatomegaly and splenomegaly, respectively);
• anemia.

The first symptoms of malaria are nonspecific. They correspond to the prodromal period and are manifested by signs characteristic of any infectious process:

• general malaise;
• severe weakness;
• back pain;
• joint and muscle pain;
• slight increase in temperature;
• decreased appetite;
• dizziness;
• headache.

A specific rise in temperature develops due to the release of plasmodia into the blood. This process is repeated several times and is reflected in the temperature curve. The cycle time is different - in some cases it is 3 days, and in others - 4.

Based on this, the corresponding varieties of malaria are distinguished (three-day and four-day). This is the period of obvious clinical manifestations when the patient seeks a doctor.

Fever in malaria has a characteristic appearance due to the successive change of three phases. At the beginning of the chill stage (the person cannot get warm, despite the warm wrapping), which is replaced by fever (second stage). The temperature rises to high values (40-41 ° C).

The attack ends excessive sweating... It usually lasts 6 to 10 hours. After an attack, a person immediately falls asleep due to a pronounced weakening that has developed as a result of intoxication and muscle contractions.

Enlargement of the liver and spleen is not determined from the very onset of the disease. These symptoms can be detected after 2-3 febrile attacks. Their appearance is due active reproduction malaria plasmodia in the liver and spleen.

When infected, anemia immediately appears in the blood, associated with the destruction of red blood cells (malaria plasmodia settle in them).

At the same time, the level of leukocytes, mainly neutrophils, decreases. Other hematological signs are the acceleration of ESR, the complete absence of eosinophils and a relative increase in lymphocytes.

These signs indicate activation immune system... She fights infection but fails. The disease progresses, and the risk of complications increases.

With a certain degree of probability, they can be predicted on the basis of unfavorable prognostic signs. These are:

• fever that occurs every day, and not cyclically (after 3-4 days);
• the absence of an interfebrile period between attacks (an increased temperature is constantly determined, which between attacks corresponds to subfebrile values);
• severe headache;
• common seizures that occur 24-48 hours after the next attack;
• critical decrease blood pressure (70/50 mm Hg and less), approaching a state of shock;
• high level of protozoa in the blood according to microscopic examination;
• the presence of plasmodia in the blood, which are at different stages of development;
• a progressive increase in the number of leukocytes;
• decrease in glucose below 2.1 mmol / l.

Major complications malaria are:

• malaria coma, which is more common in pregnant women, children and young people;
• acute kidney failure with a decrease in urine output less than 400 ml per day;
• hemoglobinuric fever, which develops with massive intravascular destruction of erythrocytes and the formation of a large amount of toxic substances;
• malarial algid, which resembles brain damage in this disease, but differs from it in the preservation of consciousness;
• pulmonary edema with an acute onset and course (often fatal);
• rupture of the spleen associated with torsion of its legs or congestion;
• severe anemia due to hemolysis;
• intravascular blood coagulation within the framework of the disseminated intravascular coagulation, alternating with pathological bleeding.

Complications in tropical malaria may be specific:

• damage to the cornea;
• clouding of the vitreous body;
• choroiditis (inflammatory lesion of the capillaries of the eye);
• visual neuritis;
• paralysis of the eye muscles.

Laboratory diagnostics of malaria is carried out according to indications. These include:

1) Any increase in body temperature in a person who is in an endemic geographic area (countries with an increased incidence).

2) Fever in a person who has received blood transfusions over the past 3 months.

3) Repeated episodes of fever in a person receiving therapy in accordance with the final diagnosis (the established diagnosis is any disease other than malaria).

4) Persistence of fever for 3 days during the epidemic period and more than 5 days the rest of the time.

5) The presence of certain symptoms (one or more) in people who have visited endemic countries in the past 3 years:

• fever;
• malaise;
• chills;
• enlarged liver;
• headache;
• enlargement of the spleen;
• decrease in hemoglobin;
• yellowness of the skin and mucous membranes;
• the presence of herpetic eruptions.

Various methods of laboratory examination can be used to verify the diagnosis:

1. Microscopic examination of blood smears (allows you to directly detect the malaria plasmodium).
2. Express test.
3. (the study of genetic material by repeatedly obtaining copies of the DNA of the malaria plasmodium in its presence in the blood).
4. Biochemical analysis is performed to establish the severity of the disease (determines the severity of liver damage, which is always observed in malaria).

All patients with a confirmed diagnosis of malaria are shown to carry out a series of instrumental research... Their results help the doctor identify possible complications and start their treatment on time.

• ultrasound scan abdominal (pay special attention to the size of the liver, kidneys and spleen);
• electrocardiogram;
• radiography of the lungs;
• echocardioscopy;
• neurosonography;
• electroencephalography.

Treatment of patients with malaria is carried out only in a hospital. The main goals of therapy are:

• prevention and elimination of acute attacks of the disease;
• prevention of complications and their timely correction;
• prevention of recurrence and carriage of malaria plasmodia.

All patients are recommended to bed rest and the appointment of antimalarial drugs immediately after diagnosis. These include:

• Primaquine;
• Chloroquine;
• Mefloquine;
• Pyrimethamine and others.

At the same time, the use of antipyretic and symptomatic drugs is shown. They are quite diverse due to the multiple organ lesions. Therefore, doctors of various specialties are often involved in treatment, and not just infectious disease specialists.

In cases where this does not happen, a change in the antimalarial drug is required. It is also indicated when plasmodia are found in the blood on the 4th day. This may indicate possible pharmacological resistance. It increases the risk of long-term relapse.
If everything goes smoothly, then in order to finally confirm the healing, special criteria are determined. These include:

• temperature normalization;
• reduction of the spleen and liver to normal size;
• a normal blood picture - the absence of asexual stages of malaria plasmodia in it;
• normal performance biochemical analysis blood, indicating the restoration of liver function.

Prevention of malaria

Malaria distribution map in the world

Tourists should pay close attention to the prevention of malaria. Even before traveling in a travel agency, you should find out if the country poses a danger for this disease.

If so, you should visit an infectious disease specialist in advance. He will recommend taking antimalarial drugs to protect the person from infection.

There is no specific vaccine for malaria.

• avoid being on the street after 17.00, because this time is the peak of mosquito activity;
• if you need to go outside, cover your body with clothes. Especially pay attention to the ankles, where mosquitoes most often bite, as well as the wrists and hands, where the skin is very thin;
• the use of repellents.

If the child is small, then parents should refrain from traveling to dangerous countries. In childhood, taking antimalarial drugs is not desirable, due to the frequent development of side effects and hepatotoxicity. Therefore, parents should weigh the possible risks.

World malaria day

The World Health Organization established International Malaria Day 2007 (60th session). It falls on April 25th.

The prerequisite for establishing the date was disappointing statistics. Thus, a new infection occurs annually in 350 - 500 million cases. Of these, 1-3 million people are fatal.

The main goal of World Malaria Day is advocacy preventive measures in relation to the disease.