Mike Coston is the Owner/Editor of Avian Flu Diary


The accepted wisdom today is that the Aedes Aegypti mosquito (and very likely the Aedes Albopictus) are the two primary mosquito vectors for Zika, Dengue and Chikungunya. Both are well distributed in Central and South America, and both make serious inroads into North America as well.

But worldwide there are well over 3,500 species of mosquito, and at least 175 of those can be found in the United States.  Most do not transmit disease, but other non-Aedes species can and do carry diseases like  Malaria (Anopheles) and West Nile (Culex).

Researchers at FIOCRUZ (Fundação Oswaldo Cruz), one of the oldest and most prestigious scientific research institutes in South America, are now investigating the possibility that other, non-Aedes mosquito species, might carry and spread Zika and Chikungunya.

The keyword is `possibility‘, as all of this is speculative and nothing has been proven yet.  But one never knows until one looks.

The concern is that the Culex mosquito – which is 20 times more prevalent than the Aedes variety in Brazil – might also play some role in the rapid spread of these viruses.  Researchers hope to have some answers in a few weeks.

Fiocruz investigating whether mosquito can also transmit zika

01.27.16 at 19:20 Folhapress


KLEBER NUNES RECIFE, PE (Folhapress) – Researchers at Fiocruz Pernambuco are investigating whether the mosquito Culex quinquefasciatus, also known as mosquito or muriçoca, can transmit the virus zika. The restlessness of experts came to realize that the French Micronesia in 2007, when the first outbreak was recorded, there was a tiny population of Aedes aegypti, the mosquito that is the vector of the disease in Brazil, and an alarming infestation of Culex. “In wild environments it was the zika virus found in other types of Aedes and Culex. Why in the urban area would be only one vector? Is that what we want to understand,” said Constance Ayres, entomologist and research coordinator.

To verify the transmission of the virus zika, the researchers infected Culex mosquitoes 200. Everyone gets the salivary glands and the digestive tracts examined. “If found the zika these materials, particularly in the salivary gland, we have a strong indication that the Culex is also vector of the disease. Then one field research will need to confirm. Otherwise, we will consider how the insect gene that blocks the action of the virus [in Culex], “said Ayres. The conclusion of this research phase shall be disclosed until the end of February.

Depending on the outcome, actions to combat the spread of disease caused by zika virus can change completely. “Unlike the Aedes aegypti mosquito, Culex lays its eggs in dirty water, like drains and sewers. Then, you need to prioritize sanitation throughout the country,” she said. The mosquito has different habits of Aedes, which, according to Ayres, increase the need for the population to redouble care not to be infected. “While the Aedes aegypti feeds on human blood during the day, Culex do so at the night,” he said.

Conventional wisdom isn’t what it used to be.  Only a few months ago Zika was considered a mild, self-limiting illness with minimal public health impact.  Today, the evidence suggests otherwise.

Which is why, even if this research doesn’t end up implicating other mosquito vectors, it is worth doing.

Read more at Avian Flu Diary