With over 200 million victims per year, malaria was and remains one of the most dangerous infectious diseases. A swift diagnosis is key to preventing severe outcomes, but it isn’t so easy. We have summarized the difficulties and how to detect the disease in spite of them.
The symptoms are non-specific
At the onset of a malaria infection, complaints are very non-specific. In addition to fever, headache, fatigue, nausea, vomiting, muscle pain and general malaise can appear. Outside of risk areas, these symptoms are often mistaken for the flu. Within risk areas, on the other hand, a malaria infection may be diagnosed prematurely without considering other possible illnesses.
Symptoms may not appear until later
The medical history must take foreign travel into account, even if the trip was taken some time ago, because the symptoms may not appear until several weeks or even months thereafter. An infection may be present even if prophylactic measures were correctly performed.
The disease goes through several phases
A malaria infection is characterized by repeated episodes of fever. The duration of fever-free intervals varies depending on the type of pathogen but can also be completely irregular, such as with Malaria tropica. Antibodies cannot be detected in the blood until days after parasitemia appears, which is why serological tests alone are not sufficient.
The clinical data are not conclusive
Thrombocytopenia, an elevated LDH level, and anemia are characteristic signs of a malaria infection – but they do not necessarily have to be present. A lack of these symptoms does not rule out a malaria infection.
Traditional laboratory diagnostics requires experienced personnel
The gold standard for diagnosing malaria is a microscopic examination of the “thick blood smear” for plasmodia. However, this method is very labor-intensive and can be performed only by experienced laboratory personnel. Most general practitioners lack this experience. An easy-to-use, quick-acting test to detect antigens or antibodies is a useful addition. Detection is sensitive and does not depend on the parasitemia status. The diagnostic confirmation of malaria continues to be based on microscopic examination of the blood.