Of Mosquitoes and Men
Malaria is spreading again – even towards Europe. In an interview, Professor Dr. Till Bärnighausen, Director of the Heidelberg Institute of Global Health, and Professor Dr. Friedrich Frischknecht, Head of a research group at the Center for Infectious Diseases, explain how the Anopheles mosquito can be contained, how the pathogen reproduces, and how mosquitoes can be used as vaccination assistants.
Professor Bärnighausen, you research health on a global scale. Today we are talking about malaria. Where does it occur, and which population groups are particularly threatened by malaria?
Till Bärnighausen: Malaria is a predominantly rural disease, and it mainly affects poorer people in Africa. It is much easier to get infected in windowless huts than in air-conditioned buildings with windows that can be closed. When it's cool, the Anopheles mosquito becomes sluggish and doesn't bite. Also, the average distances to clinics in rural Africa are long – significantly longer than in the city. People don't have cars but use minibuses or go on foot. Furthermore, poor people are often less educated.
What role does education play in prevention?
Till Bärnighausen: The higher the education level, the better the preventive behavior. An educated person is more likely to acquire new knowledge or has health-relevant knowledge from school. And they are more likely to ask a doctor or pharmacist for advice.
Professor Dr. Till Bärnighausen
How the infection works
1. The mosquito secretes infected anesthetic secretions. Its bite transports the parasite into the body.
2. It flows with the blood into the liver, penetrates the cells and multiplies.
3. The parasites infest the red blood cells and return to the liver to multiply.
4. If a mosquito bites the infected person, it can pass the parasite on to its next victim.
An employee of the Heidelberg cooperation partner in Burkina Faso interviews the mother of a small child.
© Isabel Mank/Universitätsklinikum Heidelberg
Is malaria primarily an African problem?
Till Bärnighausen: Malaria is most prevalent in the countries south of the Sahel zone, but also in South America and Asia. Our institute works in more than 50 countries – for example, in Malaysia, China, India, and Sri Lanka. We are particularly interested in China – the country has been malaria-free since 2017. One of our working groups is currently evaluating how they achieved this.
Have you gained any initial insights into this? Are there findings from other research areas that can be applied to malaria?
Till Bärnighausen: There are interesting analogies to HIV research, such as the approach of multiple prevention. It has been found that circumcising men reduces the infection rate by about 60 percent, but it does not absolve them from the responsibility of using condoms. It's similar with malaria: the vaccine is very good, but it only works to 40 percent and does not replace insect sprays, larvicides, bed nets, and doctor visits when fever occurs. In the field of science communication, we research how to convincingly convey to people that they absolutely need to get vaccinated but still have to do everything as before. We have had good experiences with education-entertainment videos – short cartoons without words that can be used effortlessly in all language communities in Africa. These videos are available on YouTube, and community health workers bring them to the communities.