Chinese researchers have disclosed that the mosquitoes incubated in Zika virus (ZIKV) contaminated water can be infected by the virus.
In the classic ZIKV transmission cycle, mosquitoes acquire the virus via biting an infected patient when infectious viral particles are released into the saliva of the mosquitoes. The mosquitos then transmit the virus to healthy people.
Before being able to fly, mosquitoes grow up in water from spawn to larvae to pupae. The researchers from Tsinghua University and Beijing Normal University collected urine samples from 89 healthy people and found that ZIKV can survive in human urine.
The researchers mixed healthy urine with ZIKV and found that up to four percent of the mosquitoes that emerged from the infected urine were ZIKV positive. Some of the infected mosquitoes transmitted ZIKV to animals.
Furthermore, the researchers collected several sewage samples to cultivate the mosquito pupae, and urine containing a low amount of ZIKV was continuously added to the sewage sample every three hours, which simulated the urination of ZIKV patients.
In this sewage condition, mosquitoes acquired ZIKV and obtained the ability to transmit the virus to animals.
The result indicated that mosquitoes breeding in a water system contaminated by human urine containing ZIKV can carry and transmit ZIKV.
This new potential transmission approach may accelerate the dissemination of ZIKV in nature.
The study emphasized the importance of improving the sanitary system in mosquito-borne disease epidemic regions and providing new possible avenues for interrupting the mosquito-borne virus transmission cycle in nature.
The stability of ZIKV is determined by the acid and alkali degree, said Cheng Gong, a professor of Tsinghua University. The virus activity dived when the pH value was reduced lower than 6.5.
Thus water pH value control could also be a ZIKV prevention method.
“All of our findings are based on laboratory experiments,” said Cheng. “We need to do further research through field investigations.”