By SEAN DUFFY
(CN) — Brazilian researchers have found the “presence of the Zika virus” in common house mosquitoes in Brazil, the nation where the epidemic initially began.
The discovery, made in the northeastern city of Recife, is the latest episode in the city’s battle with the virus. Recife has nearly one-third of all known cases of microcephaly, a congenital disorder that leads to reduced head size and potential brain damage in infants.
Concerns over the risk of Zika in Brazil have surrounded the 2016 Summer Olympics, forcing some athletes and potential visitors to reconsider attending or skip them all together.
While the findings could be troublesome for Brazil, a nation nearly crippled by political turmoil and its most severe recession in the past 80 years, the researchers caution that additional studies will be needed to determine whether the Culex mosquitoes can transmit Zika.
Health officials have said that Aedes aegypti and Aedes albopictus mosquitoes can transmit the virus, but it is still unclear whether other species of mosquitoes can as well.
In a study organized by the Oswaldo Cruz Foundation, researchers examined 500 mosquitoes and separated them into pools of between 1 and 10 mosquitoes. They found the virus in three pools of mosquitoes, though that does not mean they are capable of transmitting the virus.
“The obtained data will require additional studies in order to assess the potential participation of Culex in the spread of Zika and its role in the epidemic,” the foundation said.
Recife, a city in the impoverished state of Pernambuco, has several large slums and minimal sanitation services, which makes the northeastern city a breeding ground for Zika.
Whether or not the Culex mosquitoes are capable of transmitting the virus is especially important for the area since the Recife metropolitan area has about 20 times more of the common house mosquitoes than Aedes aegypti mosquitoes, the primary vector for Zika.
The World Health Organization called the new research a welcome addition to the existing — and growing — body of Zika research, but also cautioned that more studies are needed to determine whether Culex mosquitoes are another vector for the virus.
Tom Skinner, senior press officer for the U.S. Centers for Disease Control and Prevention, also highlighted the need for additional research to confirm its findings.
“The study would need to be replicated to have a better understanding of possible implications. Body of scientific evidence to date clearly points to Aedes being the primary vector implicated in Zika outbreaks,” he said.
A study published this past week in the journal Emerging Infectious Diseases found that Culex pipiens — a different type of Culex mosquito — was not capable of transmitting Zika, leading the authors to presume it is unlikely that Culex mosquitoes can transmit the virus.
“Although we expected that Culex pipiens mosquitoes would not be competent Zika virus vectors, our experimental verification helps exclude uncertainties surrounding the potential vectors of this emerging pathogen,” the study says.