Senegalese help Brazil fight the Zika virus | Africa | DW | 26.01.2016
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Senegalese help Brazil fight the Zika virus

Senegalese researchers who helped contain the Ebola epidemic in West Africa are training Brazilians on how to tackle the Zika virus. They have brought along a mobile lab which quickly detects the virus.

Senegalese researcher Amadou Alpha Sall brought with him to Brazil a small team and a lab which fits into a bag. He wants to help Brazilians defeat the current epidemic of mosquito-borne Zika. The virus is suspected to have caused up to 3,530 cases of brain damage in newborns through microcephaly in Brazil since last year. Microcpehaly is a rare neurological condition in which an infant's head is significantly smaller than the heads of other children of the same age and sex. It can be caused by genetic or environmental factors and often causes severe brain damage.

Amadou Alpha Sall who is director of research at the Pasteur Institute in the Senegalese capital Dakar was on the frontline of the war on Ebola in West Africa. Together with colleagues from São Paulo University‘s Institute of Biomedical Sciences (USP), Sall and his team of five travelled to Recife, in the federal state of Pernambuco. It is one of the areas with the highest incidence of Zika infections, with more than 1,200 cases of microcephaly registered.

Sall and his team carry a mobile laboratory which can diagnose the virus in a blood sample in only 15 minutes. The system developed by the Dakar team was decisive in helping contain the Ebola epidemic in West Africa. Researchers hope it will be just as effective in fighting Zika in Brazil.

The compact lab was adapted to be able to recognize the Zika virus. It can easily be transported to the most remote corners of the country. It operates on solar energy, which is important in villages where there is still no electricity.

Sall told DW that he wants to train Brazilians in detecting the virus early enough: "If you can't identify the virus, you will have no way of telling whether the epidemic is advancing, stabilizing or ebbing," he added.

Senegalese scientist Amadou Alhpha Sall

Senegalese scientist Amadou Alhpha Sall is playing a crucial role in war against Zika

The medical equipment comes with a price tag of about 8,000 euros ($8,650). But USP professor Paolo Zanotto hopes that it can be built in Brazil at a much lower cost. Zanotto has been collaborating with Sall in a series of projects for the last 15 years.

The importance of a quick detection

According to the Brazilian Ministry of Health, currently, the Zika virus is tracked by a biomolecular test known as PCR. It is a cumbersome and complex method which succeeds in detecting the virus five days after the first symptoms of the infection become manifest.

The exact spread of the Zika epidemic in Brazil has not yet been ascertained. This is because those infected, especially pregnant women, do not always show the symptoms. Zika is transmitted by Aedes aegypti, the same mosquito that carries the vectors for the dengue and chikungunya fevers.

"The Zika situation is very complicated, because in 70% of microcephaly cases registered in Recife, for instance, mothers didn't show any signs of the disease during the pregnancy. These are asymptomatic cases," explains Zanotto. He adds that the most common symptoms include fever, nausea, diarrhea, headaches, as well as body and joint aches. Itchy rashes on the face, arms and legs can also occur. This is what scientists call the viremic stage, where viruses enter the bloodstream and hence have access to the rest of the body.

"That's when you have to step in: go to the house of the people infected and get the mosquitoes there", says Zanotto. "Detection of the viremic stage is fundamental to enable us to develop efficient control mechanisms for the virus."

The head of the Senegalese team believes that the most efficient way to control the epidemic is to quickly identify and isolate infected patients. Zanotto agrees: "People think controlling a vector means killing the mosquito. But controlling a vector means controlling a person in the viremic stage, because it is the patient who infects the mosquito. Once infected, the patient himself turns into a repository for the virus."

Brazilian researcher Paolo Zanotto

Brazilian researcher Paolo Zanotto: 'Detection is key to ending the Zika epidemic'

Zika adapted

Brazilian researchers believe that this new virus was imported from French Polynesia. According to Zanotto, when news from a spike in cases of microcephaly in Brazil reached that country, researchers in Polynesia went over the data gathered during an epidemic in 2013 and 2014, and found an unusual high incidence of newborns with microcephaly.

Zika originated in Africa. But until 2007, it infected only monkeys and didn't harm humans. Scientists believe that the virus adapted as it spread throughout the continents, becoming more dangerous for humans.

While Zika is suspected to have caused the increase of microcephaly in Brazil, researchers are not sure how exactly this happens: "Apart from Brazil and Polynesia, nobody has established a clear relation between Zika and microcephaly. We do not yet have scientific proof of causality. But there is a very strong temporal and spatial connection," Sall says.

Fear among pregnant women

Researchers recommend the use of repellents, especially by pregnant women. In some cities like Sao Paulo, increased demand has led pharmacies to limit the quantity of repellent sold to individual clients.

"I live in an apartment, and I use repellent at home," says Zuleica Stefania Sabino, who is expecting her second child, "My doctor recommended that I use it". "I am worried, but I am trying not to freak out," says Viviane Gomes, who is about to give birth to her third child.

Sall and his team plan to stay in Brazil for at least one month to track the development of the epidemic: "Ebola taught us that it is possible to detect the beginning of an epidemic, but not to foresee its end," says the Senegalese researcher.

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