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Scientists discover transmissible malaria in monkeys in Brazil
Actually, malaria was eradicated in South and Southeast Brazil about 50 years ago, but since 2006, there have been recurrent outbreaks of the disease. Researchers were now trying to find out what triggered these illnesses. The physicians found out that a special form of malaria parasite is transmitted from monkeys to humans.
Researchers at the Instituto Nacional de Infectologia Evandro Chagas in Rio de Janeiro and other scientific institutions found in their study that malaria parasites in Brazil were transmitted by howler monkeys to humans. The experts published the results of their study in the journal "The Lancet".
Physicians discover malaria parasites in Brazil, which are transmitted by howler monkeys to humans. (Image: jarun011 / fotolia.com) Actually, malaria has long been eradicated in Brazil
Malaria was eradicated in Brazil about 50 years ago. Nevertheless, more than 1,000 malaria cases have occurred since 2006. There were even two outbreaks of the disease in 2015 and 2016, experts say. Is the people in Brazil facing a new malaria epidemic? ?
Analysis of DNA samples raises questions
The physicians initially assumed that the new malaria cases were caused by so-called Plasmodium vivax, one of the most important types of malaria parasites. But analysis of DNA samples has now revealed that some of the infections were not caused by a human malaria parasite. It seems much more in the new cases to be an infection, which is transmitted from animals to humans. This so-called zoonotic malaria is caused by Plasmodium simium. This parasite usually occurs only in monkeys, say the experts.
Zoonotic parasites have only been discovered twice so far
Zoonotic diseases are diseases that are transmitted from animals to humans. In the current study, it was only the second case in which zoonotic parasites were discovered, explain the scientists. A similar parasite has been found in macaque monkeys and is responsible for a high proportion of human malaria cases in Southeast Asia, explain the scientists.
People in forest areas seem to be particularly vulnerable
This malaria is not transmitted from one human to another human carrying the Simium parasite, the experts speculate. There is no evidence that the so-called zoonotic malaria can also be transmitted from person to person through mosquitoes, says author Dr. Patrícia Brasil of the Instituto Nacional de Infectologia Evandro Chagas in Rio de Janeiro. In addition, there is no current threat to people in the city of Rio de Janeiro or other areas without forest. In such areas there is no transmission of the disease.
Zoonotic malaria could make the global eradication of malaria significantly more difficult
The unique mode of transmission of monkeys to humans by mosquitoes and the fact that transmissions occur in areas of high forest cover suggest that so-called zoonotic malaria can be a serious problem in malaria control efforts. The worldwide eradication of malaria could be complicated by this form of malaria. People in Brazil should take protective measures to avoid insect bites in forest areas, the experts add.
In the past, many cases of malaria have probably been misdiagnosed
Researchers focused on 49 cases of malaria that occurred between 2015 and 2016, especially among middle-aged men. These men all lived in urban areas of the state of Rio de Janeiro and visited forests for recreational or work-related activities. In 33 cases, the DNA was successfully sequenced and the experts found that all detected parasites came from monkeys. This led to the conclusion that many cases have been misdiagnosed in the past. Further research is needed to determine if Brazilian monkey pathogens could pose a significant threat to the elimination of malaria across the continent and beyond, according to the researchers. (As)