malaria

Quick Overview

• What is malaria? A tropical-subtropical infectious disease caused by unicellular parasites (plasmodia). Depending on the type of pathogen, various forms of malaria develop (Malaria tropica, Malaria tertiana, Malaria quartana, Knowlesi malaria). However, mixed infections are possible.
• Occurrence: tropical and subtropical regions worldwide (except Australia). Especially affected is Africa. In 2016, an estimated 216 million people worldwide contracted malaria in 91 countries. Around 445,000 patients died.
• Infection: Usually by the bite of blood-sucking Anopheles mosquitoes that are infected with malaria pathogens.
• symptoms: Typical are fever episodes (hence the name intermittent fever), whose rhythm depends on the malaria form. Other symptoms include general malaise, headache, body aches, diarrhea, nausea, vomiting and dizziness.
• Therapy: Depends among other things on the malaria form. The pathogens are treated with antiparasitic drugs. Depending on your needs, specific symptoms and complications are also treated.
• Forecast: In principle, every malaria is curable. Especially with malaria tropica the prognosis depends on whether the patient is treated early and correctly.

Where does malaria occur?

Malaria occurs in tropical and many subtropical regions worldwide, except in Australia. However, the different malarial areas differ in part in what kind of malaria pathogens are spread there. In addition, the number of annual incidences (incidence) varies in each malarial area. The higher the incidence in a region, the more likely it is that not only the local population, but also a traveler will be infected with malaria.

As regards the risk of infection with malaria, the World Health Organization differentiates between the following areas:

• Areas without risk of malaria: e.g. Europe, North America, Australia, Sri Lanka
• Low (limited) malaria risk areas: e.g. Cape Verde, major cities in India, tourist areas in northern Thailand
• High malaria risk areas: e.g. almost the entire tropical-subtropical region of sub-Saharan Africa, large parts of India and Indonesia

Tip: If you want to travel to a malarial area, you should discuss with a doctor at an early stage what measures are useful for preventing malaria. A role is played by the risk of malaria in the holiday destination, the duration of the trip and the type of travel (for example, a backpacking trip or a hotel trip).

Below you will find information on the risk of malaria in selected regions worldwide:

Malaria areas in Africa

About 90 percent of all malaria cases are recorded in Africa. So, for example, exists in whole Kenya at 2,500 meters above sea level, there is a high risk of infection throughout the year, even in the cities. Particularly high is the risk of malaria along the coast and on the eastern border (as at Lake Victoria). In most cases Kenya is diagnosed with the most dangerous form of malaria – malaria tropica (caused by Plasmodium falciparum).

For example, other African countries with a high risk of malaria throughout the year are Malawi, Madagascar, Ghana, Gambia, Liberia, Congo Republic, Nigeria, Sierra Leone and the Comoros, In Tanzania the risk of infection for malaria is high all over the year in regions below 1,800 vertical meters (also in cities and national parks). Between 1,800 and 2,500 meters and on the island of Zanzibar, the risk of malaria is low. This also applies to the city of Dar es Salaam (in the rainy season, however, higher risk of malaria).

South Africa There are also regional differences in the risk of malaria infection: There is high risk between October and May in eastern Mpumalanga Province (including the Kruger National Park and neighboring national parks), in the northeast of KwaZulu-Natal (including Tembe and Ndumu Wildlife Reserve) and in the north and northeast of Limpopo province. In most other regions of South Africa, the risk of malaria is minimal to minimal. Some areas (like the cities) are even considered free of malaria.

Namibia In the Cubango Valley, the Kunene Valley and the Caprivi Strip, there is a high risk of malaria throughout the year. In the rest of the country, the risk of infection is largely low. The cities and the coast are even considered malaria free. Almost all cases in Namibia are classified as dangerous malaria tropica.

North of Botswana (including Chobe Park and Okawango Delta), the risk of malaria infection is high between November and June, but low during the rest of the year. In the south of the country, there is a minimal risk of infection throughout the year. Some areas are even classified as malaria-free, such as the Kalahari Desert and the capital Gaborone.

In Egypt In southern parts of the country, between June and October, there is a minimal risk of Plasmodium vivax to infect – one of the two possible pathogens of malaria tertiana.

Malaria areas in Asia

In Asia Depending on the region, there is a very different risk of infection for malaria. Thailand For example, there is low annual malaria scarcity in rural wooded areas throughout the year (eg in the border regions with Myanmar, Cambodia, Laos and Phuket). A year round minimal risk of infection exists in the rest of the country as well as in southern Phuket and on Koh Samui. Some areas are even considered to be free of malaria: Thailand’s capital Bangkok is one of them, as is the Ko Phi Phi archipelago. By the way, Thailand is the main one Plasmodium falciparum common, the causative agent of malaria tropica.

In Indonesia The big cities and the tourist centers in Java and Bali are free from malaria. In other regions, the risk of contracting malaria is low to high (such as Timor and the Moluccas). Plasmodium falciparum (Trigger of malaria tropica) and P. vivax (Triggers of malaria tertiana) are the most common malaria pathogens here.

In whole India At altitudes below 2,000 meters, there is a medium risk throughout the year of becoming infected with malaria. In some regions, the risk of infection is significantly increased between July and November (eg in West Bengal and Assam). In the big cities, on the other hand, it is very low year-round.

In Malaysia the risk of malaria in the interior is low to minimal throughout the year. The cities and coasts are considered malaria free.

In China Overall, there is little risk for malaria. It occurs only in certain provinces. Affected are rural areas below 1,500 vertical meters in the provinces of Hainan, Yunnan, Anhui, Henan, Hubei, Ghuizhou and Jiangsu. The rest of the country, including Hong Kong, is free of malaria.

Vietnam has a low risk of malaria throughout the year in regions below 1,500 meters altitude. The regions right on the Red River, the coast north of Nha Trang and the big city centers are not malaria areas.

Sri Lanka is also not considered a malaria area.

Malaria areas in the Caribbean, Central and South America

In the Caribbean there is in Haiti and the Dominican Republic All year round, a low to minimal malaria risk. The Dominican cities of Santo Domingo (capital) and Santiago are even considered malaria free. In Haiti is exclusive, mainly in the Dominican Republic Plasmodium falciparum (Pathogen of malaria tropica) spread.

On jamaica Occasionally, cases of malaria tropica are registered in the region around the capital Kingston.

In Mexico Malaria is not very common: the cities, the Yucatan peninsula, which is popular with tourists, as well as important archaeological sites are considered malaria-free. A low risk of infection exists, for example, in the border region to Guatemala. As malaria parasite is in Mexico only Plasmodium vivax common, one of the two triggers of malaria tertiana.

In Guatemala It is also rare to run the risk of getting infected with malaria. The cities of Guatemala City (capital) and Antigua and Lake Atitlán are considered malaria free.

Also in El Salvador and Costa Rica there is at most a minimal malaria risk. When diseases occur, it is always the most unproblematic Malaria tertiana (triggered by Plasmodium vivax).

In South America certain regions are located in French Guiana, Guiana, Surinam and Venezuela a high malaria risk. Malaria areas are less susceptible to infection Brazil, Bolivia, ecuador, Colombia, Peru, Paraguay and Panama.

Malaria areas in the Middle East

In the Turkey The tourist centers in the west and southwest of the country are considered malaria free. Southeastern Anatolia has a minimal malaria risk between May and October in some regions. Since here only the malaria parasite Plasmodium vivax occurs, only the most harmless form of malaria tertiana is registered.

in the Iraq There is a minimal malaria risk between May and November in areas below 1,500 meters altitude, especially in the northeast of the country. in the Iran Some regions have a minimal risk of infection between March and November, for example the province of Kerman.

in the Yemen You can get infected with malaria all year round, but the risk is low. Only the capital Sana’a (Aden) is classified as malaria free.

malaria prophylaxis

There is no vaccine against malaria. However, those who adhere to various protective measures can prevent contagion. These include above all measures that reduce the risk of mosquito bites in malaria areas. So you should, for example, in such areas bright clothes which covers the body as comprehensively as possible (long sleeves, long pants, socks). If necessary, you can use the clothes beforehand Mosquito repellent impregnate. It makes sense, too mosquito-proof sleeping placewith a mosquito net in front of the window and a mosquito net over the bed.

In addition, there is also one Malaria prevention with medication (Chemoprophylaxis) possible. Whether this makes sense in individual cases and which medications are the most suitable, you should discuss with a doctor early before traveling to a malaria area.

Read more about the different ways to prevent malaria in the text malaria prophylaxis.

Malaria: causes and risk factors

Malaria is caused by small, single-celled parasites called plasmodia. There are about 200 species. Five of them can cause diseases in humans:

• Plasmodium falciparum: Trigger of malaria tropica, the most dangerous malaria form. Occurs in most malaria areas worldwide.
• Plasmodium vivax and Plasmodium ovale: Trigger of malaria tertiana. P. vivax is mainly distributed in North Africa, the Middle East, Pakistan, India, Nepal, Sri Lanka and Central America. P. ovale occurs mainly in West Africa.
• Plasmodium malariae: Trigger of malaria quartana. Occurs in tropical regions.
• Plasmodium knowlesi: Only distributed in Southeast Asia. Primarily causes malaria in monkeys (macaques) and only occasionally in humans.

Malaria: transmission routes

The malaria parasites are most commonly caused by the Engraving of a bloodsucking, female mosquito of the genus anopheles transmitted, which is infected with plasmodia. The Anopheles mosquito (colloquially: Malaria mosquito) is exclusively twilight and nocturnal. This means that the malaria infection is usually caused by a sting in the evening or at night. In principle, all mammals can become infected with plasmodia. However, transmission from other animals to humans is extremely unlikely.

There is a simple formula for the risk of infection in a particular region: the more Anopheles mosquitoes in an area carry the pathogen, the more people infect them. If these patients are not treated and stung again by an unaffected mosquito, they can take in the pathogen and transfer it to another person at the next blood meal.

Very rarely do people outside of malarial areas contract tropical diseases. So there is for example the so-called Airport malaria: Infected Anopheles mosquitoes imported by plane can sting people in the plane, at the airport or in its immediate vicinity and infect them with the malaria parasite.

Transmission of the malaria parasite is also over blood transfusion or over infected needles (hypodermic needles, infusion needles) possible. Due to the strict safety regulations, this only happens extremely rarely in Germany. In blood transfusions in malaria areas, the risk of infection may be greater.

A transmission is also in rare cases too from a pregnant woman to the unborn child possible: The pathogen can pass through the mother cake (placenta) from maternal to childish blood.

Sickle cell anemia offers some protection against malaria. Malaria is much rarer and much less pronounced in people with this hereditary disease. In sickle cell disease, the shape of the red blood cells is so altered that the malaria parasite can not or only partially infest them to multiply in it. This positive effect is probably the reason why sickle cell anemia is particularly common in many malaria areas.

Life cycle of malaria pathogens

The malaria parasites are called so-called sporozoites transferred from the mosquitoes to humans. Sporozoites are the infectious stage of development of the pathogens. The parasites enter the liver via the bloodstream and penetrate into liver cells. In the cell interior, they transform into the next stage of development: schizontsthat fill almost the entire liver cell. Thousands of mature ones are created inside merozoites, Their number depends on the type of malaria pathogen: bei Plasmodium falciparum (Causative agent of the dangerous malaria tropica) it is highest.

Finally, the schizont bursts and releases the merozoites into the blood. They infect red blood cells (erythrocytes). Once a merozoite has penetrated, it grows to another giant schizont that virtually fills the red blood cells. Inside the schizont, many new merozoites are forming. As soon as the schizont (and the surrounding red blood cell) bursts open, the merozoites become free and can in turn infect red blood cells. In malaria tertiana, M. quartana and Knowlesi malaria, the affected erythrocytes burst synchronously to release the merozoites. The result is rhythmically occurring feverish spasms, In the malaria tropica, the eruption of erythrocytes is not synchorn, so irregular feverish spasms arise.

In Plasmodium vivax and P. ovale (causative agent of malaria tertiana), only part of the merozoites in the red blood cells develop into schizonts. The rest goes into a resting phase and remains in the form of so-called hypnozoites for months to years in the erythrocytes. At some point, these forms of rest can become active again and turn into schizonts (and further to merozoites). That’s why malaria tertiana can cause relapses years after infection.

Some merozoites transform into red blood cells not in schizonts, but in long-lived ones female and male gametes (gametocytes), If the malaria patient is again stung by anopheles mosquito, it also absorbs such gametocytes with the blood meal. In the mosquito stomach, female and male gametocytes fuse into one fertilized egg cell (oocyst), From her go numerous sporozoites out. They will be transferred back to a human at the next blood meal of the mosquito – the circle closes.

Is malaria contagious?

The malaria parasite can not be transmitted directly from human to human – except through blood contact, such as between an infected pregnant woman and her unborn child, or through contaminated blood transfusions. Otherwise, there is no danger to other people from sufferers.

Malaria: incubation period

Malaria does not break out immediately after becoming infected with the virus. Instead, some time passes between the infection and the onset of the first symptoms. The duration of this incubation period depends on the pathogen type:

• Plasmodium falciparum (Trigger of malaria tropica): 7 to 15 days
• Plasmodium vivax and Plasmodium ovale (Trigger of M. tertiana): 12 to 18 days
• Plasmodium malariae (Trigger of M. quartana): 18 to 40 days
• Plasmodium knowlesi (Trigger of Knowlesi malaria): 10 to 12 days

In some cases, the incubation period may in some cases be much longer: both Plasmodium vivax as well as P. ovale can form resting forms (so-called hypnozoites) in the liver. These can leave the liver even after years, multiply in the red blood cells and cause symptoms. at P. vivax is this up to two years possible after infection, at P. ovale up to five years after that.

Plasmodium malariae does not form any forms of rest (hypnozoites). However, the number of parasites in the blood can be so low that until the onset of symptoms up to 40 years can pass.

Malaria: symptoms

In general, malaria symptoms like fever, Headache and body aches as well as one general malaise first up. Also diarrhea, nausea, Vomit and dizziness are possible. Some patients mistakenly attribute the symptoms to a simple flu or influenza infection.

In detail, there are some differences in the symptoms of the various malaria forms:

Symptoms of malaria tropica

Malaria tropica is the most dangerous form of malaria. Symptoms are more severe here than in other forms and significantly weaken the organism. The reason is that the pathogen (Plasmodium falciparum) infects both young and older red blood cells (unlimited parasitemia) and so many of them are destroyed in the further course.

Symptoms of malaria tropica are mostly Headache and body aches, fatigue and irregular episodes of fever or even continuous fever, Also Vomit such as Diarrhea with fever can occur. Some patients also develop respiratory ailments like one dry cough, In addition, the massive decay of red blood cells triggers one anemia (Anemia).

Consequences & complications:

In the course of the disease, the Increase spleen (Splenomegaly) because she has to do hard labor in malaria: she needs to break down the many red blood cells that are being destroyed by the malaria parasite. If the spleen exceeds a critical size, the surrounding capsule may rupture (splitting of the spleen, splenic rupture). This leads to heavy bleeding (“Tropical Splenomegaly Syndrome”).

Also one Enlargement of the liver (Hepatomegaly) as a result of malaria infection is possible. It can be associated with jaundice (jaundice).

The concomitant enlargement of the liver and spleen is called hepatosplenomegaly.

In about one percent of the subjects, the pathogens invade the central nervous system (Cerebral malaria). This can cause, for example, paralysis, seizures and disturbances of consciousness, even coma. After all, those affected can die.

The malaria parasites can also affect the lungs (pulmonary malaria). Common complications include pulmonary edema (accumulation of water in the lungs). The heart can also be affected (cardiac malaria), which can cause heart muscle damage.

Other possible complications of malaria tropica are one impaired kidney function (acute kidney failure), Circulatory collapse, anemia as a result of the increased decay of red blood cells (hemolytic anemia) and adisseminated intravascular coagulopathy“(DIC): Inside the intact blood vessels, the blood clotting is activated, which massively platelets are consumed – it develops a lack of platelets (thrombocytopenia) with increased bleeding tendency.

Especially with pregnant women and children, there is a risk that a malaria tropica with hypoglycemia (Hypoglycemia). Possible signs include weakness, dizziness, cravings and seizures.

Symptoms of malaria tertiana

In this disease, the malaria symptoms are usually much weaker. It starts with sudden fever and other nonspecific complaints like a headache. In the further course arise rhythmic fevers a: They usually occur every second day on (thus in the 48-Stunden-Abstand). Hence the name suffix “tertiana”: day 1 with fever, day 2 without fever, day 3 again fever. The fever bouts typically show the following course:

Patients get chills first in the late afternoon and then fever around 40 degrees Celsius very quickly. After about three to four hours, the temperature quickly drops back to normal, accompanied by heavy sweats. Complications and deaths are rare. But it can still come to relapse after years.

Symptoms of malaria quartana

In this rare form of malaria occur Fever bouts every third day (ie at 72-hour intervals). The temperature can rise up to 40 degrees and be accompanied by severe chills. After about three hours, the fever stops under heavy sweats.

Possible complications are kidney damage and splenic rupture. In addition, relapses can occur up to 40 years after infection.

Symptoms at Plasmodium knowlesi-Malaria

This malaria form, which is limited to Southeast Asia, was previously known only in certain monkeys (macaques). However, it can rarely occur in humans when it is transmitted by Anopheles mosquitoes. It is sometimes mistaken for malaria tropica or malaria quartana. However, that goes P. knowlesiMalaria typically with daily fever episodes associated. Otherwise, as with other forms of malaria, chills, headaches and body aches can occur. The disease can be severe, but rarely fatal.

You can also simultaneously infect with various Plasmodium species, so that the symptoms can be mixed.

Malaria: examinations and diagnosis

If you have been (or still are) in a malaria risk area in the weeks leading up to the onset of the symptoms, you should consult a doctor (family doctor, tropical medicine, etc .). Especially in the case of the dangerous malaria tropica, a fast start of therapy can possibly be life-saving!

Even months after a trip to a malaria risk area, every unexplained feverish illness should be investigated accordingly. Because sometimes malaria breaks out only very delayed.

Doctor-patient conversation

The doctor will first discuss your with you To raise medical history (Anamnesis). Possible questions are:

• Which complaints do you have exactly?
• When did the symptoms first appear?
• When was the last time you were abroad?
• Where were you and how long were you there?
• Were you stung by mosquitoes in the travel destination?
• Have you taken any drug malaria prophylaxis in the travel destination?

blood tests

At the slightest suspicion of malaria (intermittent fever), your blood is examined microscopically for malaria pathogens. For this purpose, a “thin blood smear” and / or “thick blood smear” (“thick drop”) is made:

At the thin blood smear a drop of blood is spread thinly on a slide (small glass plate), air-dried, fixed, stained and viewed under the microscope. Staining is used to visualize any plasmodia that may be present in the red blood cells. The advantage of this method is that the plasmodium species can be easily determined. However, if only a few red blood cells are affected by plasmodia, the infection may be overlooked.

The more accurate detection method is therefore the thick blood smearbecause here the plasmodia are enriched by six to ten times: For this purpose, a thick drop of blood is applied to the slide, air-dried and stained without fixation. Due to the lack of fixation, the dye destroys the red blood cells, releasing the stained plasmodia.

The disadvantage of the thick blood smear is that the determination of the Plasmodienart is not as easy as the thin smear. At most, the pathogens of the lethal malaria tropica (Plasmodium falciparum) from the other malaria pathogens (such as P. vivax). For accurate identification the thin blood smear is needed.

If no plasmodium can be detected in the blood test, malaria may still be present. In the early stages, the number of parasites in the blood can be so low that they are undetectable even in thick drops. Therefore, if malaria continues to be suspected and the symptoms persist, the blood should be repeatedly tested for plasmodia at intervals of 12 to 24 hours.

If the investigation is due to a malaria infection Plasmodium falciparum or P. knowlesi results, the amount of parasites in the blood is determined. These Parasite density in the blood (Parasitämie) influences namely the therapy planning.

If the direct detection of pathogens in the blood has confirmed the malaria suspicion, help more blood valuesto estimate the severity of the disease. These include, for example, red and white blood cells, platelets (platelets), C-reactive protein (CRP), blood sugar, creatinine, transaminases and bilirubin.

Malaria rapid test

For some time, there are also malaria rapid tests. You can detect plasmodium-specific proteins in the blood. However, malaria rapid tests are not used by defaultto diagnose an infection because they also have drawbacks: the test result may be incorrectly negative, both with very high and very low levels of plasmodium in the blood. In addition, a rapid malaria test can not distinguish between the various malaria pathogens. It is therefore only used in certain cases, for example if a timely reliable blood test (thick and thin blood smear) can not be performed.

Detection of plasmodium genetic material

It is also possible to examine a blood sample for plasmodium DNA (DNA), to amplify it by means of polymerase chain reaction (PCR) and thus to detect the exact type of pathogen. But that takes a relatively long time (several hours) and is very expensive. Therefore, this diagnostic method is used only in special cases, such as very low parasite density or if someone has been infected with various malaria pathogens (mixed infection).

Further investigations

The physical examination After confirmed malaria, the doctor will provide information about your general condition and the severity of the infection. For example, the doctor measures your body temperature, heart rate, respiratory rate, and blood pressure. The heart rate can be determined by ECG. In addition, the doctor checks your state of consciousness. In a palpation examination, he can also detect an enlargement of the spleen and / or liver.

In case of poor general condition or complicated malaria (such as high parasite count in the blood, infestations of the brain, kidneys, lungs, etc.) further investigations are necessary additional blood values determined (such as calcium, phosphorus, lactate, blood gases, etc.). In addition, the amount of urine measured and the Thorax X-rayed (Chest x-ray). Also the creation of blood cultures makes sense: sometimes joins malaria a bacterial infection (co-infection), which can be detected by culturing the bacteria in a blood sample.

Malaria: treatment

Malaria therapy depends on several factors:

• Type of malaria (M. tropica, M. tertiana, M. quartana, Knowlesi malaria)
• possible comorbidities
• Presence of pregnancy
• Allergies as well as intolerances and contraindications (contraindications) against malaria medications

M. tropica and M. knowlesi also influence the Severity of the disease the therapy planning. It also plays a role in whether the patient in advance Medicines for malaria prophylaxis has taken or currently any concomitant medications applies (against other diseases).

As a rule, the disease is treated by medication. Depending on the pathogen, different antiparasitic agents are used. Due to the widespread use of drugs in the past, many pathogens are already resistant to certain drugs (such as chloroquine). Therefore, malaria patients often need to be treated with two or more different agents.

Malaria tropica: therapy

Patients with the potentially lethal malaria tropica must always be hospitalized (inpatient). In uncomplicated cases They usually receive one of the following combination preparations (in tablet form):

• Atovaquone / proguanil
• Artemether / lumefantrine
• Dihydroartemisinin / piperaquine

The tablets usually need to be taken for three days. Depending on the preparation, possible side effects include nausea and vomiting, abdominal pain, diarrhea, headache, dizziness, cardiac arrhythmias and coughing.

at complicated malaria tropica treatment on the intensive care ward is necessary. For example, physicians speak of “complicated” when there is a clouding of consciousness, cerebral seizures, respiratory depression, severe anemia, shock symptoms, kidney weakness, hypoglycaemia or high parasite density in the blood. Therapy of choice in such cases is the antiparasitic agent artesunate, It is administered several times over the course of 72 hours as a syringe (injection). Thereafter, the treatment with combination tablets with Atovaquone / proguanil continued. Mögliche Nebenwirkungen von Artesunat sind etwa fieberhafte Reaktionen, Übelkeit, Erbrechen und Durchfall.

Ist Artesunat nicht verfügbar, wird eine komplizierte Malaria tropica stattdessen mit Chinin behandelt (sofern der betreffende Malaria-Erreger nicht dagegen resistent ist). Dabei ist Vorsicht geboten, weil zum Teil schwere Nebenwirkugnen auftreten können wie Hör- und Sehstörungen, Ohrgeräusche (Tinnitus), Übelkeit und Erbrechen, Herzrhythmusstörungen, Abfall der Blutplättchen-Zahl (mit der Gefahr innerer Blutungen), Gefäßentzündung (Vaskulitis) oder Lungenödem.

Zusätzlich zu Chinin können die Patienten Doxycyclin beziehungsweise Clindamycin erhalten. Beides sind antibiotics, wirken also gegen Bakterien. Sie besitzen aber auch antiparasitäre Eigenschaften.

Malaria tertiana: Therapie

Patienten mit Malaria tertiana können oft ambulant behandelt werden. Sie erhalten Kombinationstabletten mit Artemether/Lumefantrin or Atovaquon/Proguanil, obwohl diese Medikamente für diese Krankheitsform nicht offiziell zugelassen sind (“off-lable-use”). Die Anwendung der Tabletten erfolgt in gleicher Weise wie bei Malaria tropica, also über drei Tage.

Danach sollten die Patienten noch zwei Wochen lang Tabletten mit dem Wirkstoff primaquine einnehmen. Sie töten Ruheformen der Errreger (Hypnozoiten) in der Leber ab und können damit spätere Rückfälle der Infektion verhindern.

Malaria quartana: Therapie

Auch Malaria quartana lässt sich meist ambulant behandeln. Therapie der Wahl ist der antiparasitäre Wirkstoff chloroquine, In der Regel verschreibt der Arzt vier Dosen, die im Lauf von 48 Stunden eingenommen werden müssen.

Eine Anschlussbehandlung mit Primaquin wie bei Malaria tertiana ist hier nicht nötig, weil der Erreger der Malaria quartana (Plasmodium malariae) keine Dauerformen in der Leber (Hypnozoiten) ausbildet.

Knowlesi-Malaria: Therapie

Die Knowlesi-Malaria wird in der gleichen Weise behandelt wie Malaria tropica. Das heißt: Die Behandlung erfolgt im Krankenhaus, bei schwerem Verlauf sogar auf der Intensivstation. In unkomplizierten Fällen erhalten die Patienten drei Tage lang ein Kombinationspräparat aus zwei Wirkstoffen (wie Atovaquon/Proguanil). Eine kompliziert verlaufende Knowlesi-Malaria (Bewusstseinstrübung, zerebrale Krampfanfälle, starke Blutarmut etc.) wird bevorzugt mit Artesunat behandelt. Als Alternative steht Chinin (in Kombination mit Doxycyclin bzw. Clindamycin) zur Verfügung.

Unterstützende Behandlung

Die Behandlung mit antiparasitären Wirkstoffen bekämpft direkt die Ursache einer Malaria – die Plasmodien. Bei Bedarf werden zusätzlich Maßnahmen gegen die Malaria-Symptome getroffen. So kann man etwa das hohe Fieber mit dem fiebersenkenden Mittel Paracetamol und/oder Hausmitteln wie Wadenwickeln senken. Wichtig ist außerdem eine körperliche Schonung.

at komplizierter Malaria tropica such askomplizierter Knowlesi-Malaria hat die unterstützende Behandlung – neben den oben beschriebenen fiebersenkenden Maßnahmen – einen großen Einfluss auf die Prognose: Beispielsweise kann der Arzt bei starker Blutarmut Bluttransfusionen verordnen. Gegen zerebrale Krampfanfälle helfen Medikamente mit Benzodiazepin-Abkömmlingen. Bei Nierenschwäche beziehungsweise Nierenversagen kann eine Dialyse notwendig werden.

Eine Malaria in der Schwangerschaft oder Stillzeit sollte immer in Rücksprache mit einem tropenmedizinischen Institut behandelt werden.

Malaria: Verlauf und Prognose

Der Krankheitsverlauf und die Prognose hängen bei Malaria davon ab, welche Form vorliegt und in welchem Stadium die Krankheit erkannt wurde. Malaria tertiana and Malaria quartana verlaufen in der Regel relativ mild. Manchmal heilen sie sogar ohne Behandlung nach einigen Rückfällen spontan aus. Nur selten kommt es zu schweren Verläufen und Todesfällen. Also the Knowlesi-Malaria verläuft nur selten tödlich.

Am gefährlichsten ist die Malaria tropica, Grundsätzlich ist auch diese Malaria heilbar, besonders wenn sie frühzeitig und richtig behandelt wird. Unbehandelt können sich schon nach wenigen Tagen ernste Komplikationen entwickeln. Dazu zählen zum Beispiel Störungen der Lungenfunktion mit Atemnot, akutes Nierenversagen, Bewusstseinsstörungen und Blutdruckabfall. Diese Komplikationen müssen dringend behandelt werden, sonst kann es schließlich zum Ausfall lebenswichtiger Organe (Gehirn, Nieren etc.) kommen – der Patient stirbt. Laut Statistik sterben zwei von zehn Patienten, wenn die malaria tropica nicht oder nur unzureichend behandelt wird.

Additional information

guidelines:

• Leitlinie “Diagnostik und Therapie der Malaria” der Deutschen Gesellschaft für Tropenmedizin und Internationale Gesundheit (2016)