Malaria

Malaria is an infectious disease caused by a parasite known as a Plasmodium. This is a single-cell parasite, which is transmitted by the Anopheles mosquito.

Malaria is found in almost all tropical and subtropical regions, meaning in very warm regions near the equator and in the adjacent temperate zones. The disease is found in approximately 90 countries and on all continents except for Australia.

The various types of malaria have different levels of severity, whereby each variation is caused by a different species of the Plasmodium parasite.

More than three quarters of malaria cases recorded in Germany are malaria tropica. This is the most dangerous form of the disease. People traveling from Germany do not generally have immunity against it.

Therefore, it is particularly important to take preventive (prophylactic) measures when visiting a region considered to be at high risk for malaria.

What is meant by airport malaria and suitcase malaria?

A very rare form of malaria contracted outside of regions where it is spread is known as “airport malaria”. It is transmitted by imported mosquitoes either in an airplane, at an airport, or in the immediate vicinity.

“Suitcase malaria” (also known as “luggage/baggage malaria”) occurs when mosquitoes are imported in the suitcase of an airplane passenger. They can infect the passenger or people in their immediate environment after they travel back to their country of origin.

The incubation period, meaning the time from infection to the onset of symptoms, is usually between 7 and 40 days. In rare cases, it may last several months.

The first symptoms of malaria include:

• fever
• chills
• headache and limb pain
• diarrhea
• vomiting
• general feeling of being unwell

Often, these symptoms are misinterpreted as the flu or a gastrointestinal infection.

People may also experience coughing, elevated pulse and accelerated breathing.

Depending on which type of malaria they have, the fever they experience follows a different pattern.

Malaria tropica

The fever that occurs does not follow the fever pattern of other types of malaria. People may also experience cramps, impaired consciousness, anemia, red spots on the skin, yellowing of the skin and breathing difficulties. Malaria tropica is fatal in 2 out of every 10 people who have no immunity.

Malaria tertiana

A typical symptom of malaria tertiana is a high fever that spikes and then goes back down, occurring cyclically every three days. This is the reason it is called “tertiana”. Its name essentially means “three-day fever”. The fever attack is usually accompanied by chills and lasts 3 to 4 hours. Malaria tertiana is not usually fatal.

Malaria quartana

Malaria quartana is less common than other types of malaria. With this type of malaria, fever attacks occur every four days. Its name essentially means “four-day fever”.

Knowlesi malaria

This type of malaria is found only in Southeast Asia. It is characterized by daily bouts of fever and is just as dangerous as malaria tropica.

Malaria is an infection caused by a single-cell parasite of the genus Plasmodium. Different Plasmodium species are responsible for the various forms of malaria.

How do people become infected with malaria?

The single-cell parasite is primarily transmitted through the bite of the female Anopheles mosquito.

Infected pregnant women can transmit the malaria pathogen to their unborn babies. This is rare. Nevertheless, pregnant women, and therefore their unborn children, are particularly vulnerable to malaria.

The only other person-to-person transmission route for malaria is via blood. This is very rare.

What happens in the body following infection?

Following infection, the parasites initially multiply in the liver. The infection remains unnoticed at this stage.

Next, the parasites attack the red blood cells (erythrocytes) and multiply again. After two to three days, the erythrocytes rupture, releasing the parasites into the blood.

This breakdown of blood cells causes an attack of fever, which intensifies as the number of parasites continues to grow. As the disease progresses, infected blood cells block small blood vessels. This causes further symptoms and complications.

Generally speaking, the risk group comprises people traveling from countries such as Germany where there is no malaria, apart from some cases of the disease that are brought back from travels abroad. As a result, the population generally has no immunity against malaria.

Older people, small children and pregnant women are at highest risk of developing a severe and fatal form of the disease.

Approximately two-thirds of malaria deaths worldwide occur in children under the age of 5.

Malaria during pregnancy

Contracting malaria during pregnancy is very risky for both mother and child. However, taking preventive drugs (malaria prophylaxis) is not recommended during pregnancy. With any of the drugs available, there is no guarantee that the development of the unborn child will be unaffected. For this reason, pregnant women should postpone travel to regions with malaria until after the pregnancy.

Malaria occurs very frequently in certain at-risk regions. Almost all occurrences in Germany are brought back by people who have traveled abroad.

Malaria worldwide

Around 40 percent of the world’s population live in a malaria-endemic region. These are regions where malaria is continuously at an elevated level.

Every year, 200 to 300 million people worldwide contract malaria. Almost 600,000 people die as a result, with around three-quarters of these deaths occurring in children under the age of 5.

Over 90 percent of malaria infections occur in African countries. Malaria infections in Asia and South America have significantly declined. In the last few years, individual cases of malaria tertiana have been found in countries in southern Europe, such as Spain and Greece.

Malaria in Germany

Practically all people from Germany who contract malaria become the infection in an at-risk region. In recent years, approximately 300 to 1,000 cases of malaria have been recorded in this country. Boys and men are infected more than twice as often as girls and women.

Most cases of malaria are brought in from African countries. Malaria is particularly common among people returning from trips to Cameroon, Nigeria, Ghana and Togo. Outside of Africa, most infections originate in India.

The various types of malaria progress in very different ways.

Progression depends mainly on:

• whether the patient has already had malaria once or more than once before and has acquired a degree of immunity
• the type of malaria involved

Malaria tropica

Malaria tropica is by far the most dangerous form of malaria. Common initial symptoms are fatigue, headaches and aching limbs, diarrhea and intermittent bouts of fever.

Many complications can occur:

• acute kidney failure
• damage to the lungs
• enlargement of the spleen
• enlargement of the liver
• circulatory collapse
• red blood cell deficiency
• internal bleeding

The parasite may also attack the brain (this is known as cerebral malaria). Typical symptoms are seizures and brief losses of consciousness or even coma.

Malaria tertiana

Malaria tertiana is rarely accompanied by life-threatening complications. However, the symptoms can be severe. A typical symptom is an intermittent fever that spikes and then goes back down, appearing every three days. The person experiences chills, during which the fever quickly spikes to 40 degrees Celsius. After three to four hours of profuse sweating, their body temperature decreases and eventually returns to normal. Following a recovery, relapses may occur after several weeks or even years.

Malaria quartana

Malaria quartana is less common than the other types of malaria. It generally occurs without complications. A typical symptom is a fever that occurs every four days. With this form of malaria, relapses can occur after the initial recovery.

Knowlesi malaria

Typical symptoms are bouts of fever. Knowlesi malaria can be as severe as malaria tropica.

To date, there is no vaccine to protect travels to regions where malaria occurs. This makes other preventive measures especially important.

Those who plan to spend time in a region with malaria must speak with a doctor about the necessary preventative measures (individual prophylaxis) before leaving. These include taking medication prophylaxis (chemoprophylaxis) and using mosquito protection.

Chemoprophylaxis

There are various types of medication that have a preventive effect against malaria. A doctor should be consulted about which medication is most suitable before the trip.

Usually, medication is taken for the first time shortly before the trip and must then be taken for the duration of the visit to the malaria region. It must also be continued for up to one week after returning home.

The following generally applies:

• Generally, a chemoprophylaxis is strongly recommended for trips to countries with a high transmission potential.
• A chemoprophylaxis is generally not needed for trips to countries with a low or medium risk of malaria. However, when traveling to remote regions, it may be a good idea to take along some medication for self-treatment in an emergency.

Mosquito repellent

The Anopheles mosquito is active a dusk. The following protective measures are recommended when traveling to a region where there is a risk of malaria:

• Stay in rooms that keep mosquitoes out and have air conditioning and insect screens whenever possible.
• Sleep under a mosquito net, preferably one that has been treated with substances to kill insects.
• When outdoors, wear pale/light-colored, long clothes that cover the arms and legs. It is best to also spray clothes with special insect spray for clothing.
• Use mosquito repellent spray or cream containing the active ingredients DEET, icaridin or lemon eucalyptus oil.

If malaria is suspected, a doctor must start diagnostic tests immediately to determine whether the blood contains malaria pathogens (Plasmodium parasites). It is important to detect which species of Plasmodium parasites are present as soon as possible in order to diagnose the specific form of malaria that has been contracted and make decisions about the next steps in treatment.

A blood sample is needed for diagnosis. The parasites causing the infection are identified using a microscope that examines the blood. This requires a lot of experience. Often, a diagnosis can only be made by specialist doctors or centers of expertise in tropical medicine.

If microscopic diagnosis is not available, rapid tests may be used. However, these are less accurate and reliable.

A list of tropical medicine institutions in Germany can be found on the website of the German Society for Tropical Medicine and Global Health (Deutsche Gesellschaft für Tropenmedizin und Globale Gesundheit e.V.).

The type of malaria a person has and how severely ill they are will determine how the disease is treated.

Treatment for malaria tropica should be administered in hospital, ideally in an intensive care ward in a hospital with experience in tropical medicine.  

Malaria tropica and Knowlesi malaria

If the case of malaria tropica or Knowlesi malaria in question is uncomplicated and the patient has no life-threatening symptoms, medication with two compatible active ingredients is used to treat the patient.

If the case of malaria tropica or Knowlesi malaria is complicated and life-threatening symptoms are present, such as brief losses of consciousness or difficulty breathing, the patient must be treated in an intensive care ward. Specific malaria drugs are also used.

Malaria tertiana

Malaria tertiana is mainly treated with the same medication used for malaria tropica without complications. To prevent a relapse, another type of medication must be taken for a certain period of time following the initial treatment.

Malaria quartana

Several drug combinations can also be used to treat malaria quartana.