A mosquito testing positive for Zika virus infection in Chikkaballapur district of Karnataka has added to the concerns about the vector borne infection. However, the Zika viral infection has not been seen in humans. The Zika virus in the mosquito was detected during routine mosquito pool surveillance. The health department has issued an advisory to curb mosquito menace and follow precautions.
Out of the 100 samples of mosquitoes taken for random pool sample test, one of the mosquitoes collected from Talakayalabetta village in Shidlaghatta taluk, Chikkaballapur district tested positive for Zika. The state government has now issued an alert in the five kilometre radius of Talakayalabetta village where the sample was derived from. Total six mosquito samples were collected from Chikkaballapur out of which one sample turned out to be positive for Zika and the rest were negative. The sample was collected on September 25.
“The virus was found only in a mosquito sample during a routine mosquito pool surveillance check,”said Karnataka health minister Dinesh Gundu Rao.
“There have been no case of Zika infection seen in humans in Karnataka as of now. Currently we have seen the positivity for Zika infection in a mosquito. Three persons who have high fever have been under monitoring and their blood samples have been sent for further testing and the results are expected within three days,” Rao told Happiest Health.
The sample was collected on September 25. The Zika virus in the mosquito was confirmed by the National Institute of Virology, Pune on October 25.
In December 2022, Karnataka had seen its first reported case of Zika when a five year old girl had tested positive for the vector borne infection. The girl had recovered and the infection was not found in others.
Dr A Usha, entomologist, health and family welfare department, Karnataka says that the Zika presence in a mosquito was seen through random samples collected during mosquito surveillance.
“We do test the mosquito where ever the mosquito menace is high,” said Rao.
How are mosquitoes tested?
Not only human beings, but mosquitoes also undergo Zika tests. “We randomly collect the vector mosquitoes. Not all mosquitoes cause the disease and process for virus isolation and conduct RTPCR tests on them. A series of tests will done to check if the mosquito is infected with dengue, Chikungunya, Zika. The DNA will be extracted through the mosquito. This is being done routinely. Random sampling tests have shown the virus circulation,” said Dr Usha.
She added that it is the second time Karnataka is seeing a mosquito testing positive for Zika. “Prior to this it was seen in a mosquito in Gadag in North Karnataka during November 2022. No human infections were seen earlier too,” she said.
Dr Usha notices that there is a lack of awareness among the public about mosquito breeding. “People tend to think that mosquitoes breed only on dirty, polluted water. Wherever there is water stored within our houses too, in barrels, cement tanks, the mosquitoes breed. Clean water storing in the residential premises and keeping it open is a problem,” she says, mentioning that the larva removal measures through chemical sprays is a must.
Dr Usha adds that many associate mosquito menace to monsoon only, which is not true. “Mosquito is a perineal breeder and container breeder, which means that irrespective of the seasons, mosquito breeding occurs. During rainy seasons, water gets collected in discarded containers and hence the density of the vector and the number of breeding sites increases
Symptoms of Zika
Typical symptoms of Zika are fever, headache, red eyes, body pain, rashes on the body. The health department officials say that mosquito control measures must be implemented to reduce the larvae breeding and prevent vector borne infection.
Zika virus in a mosquito sample has been detected in Karnataka, leading to concerns about the vector borne infection. While there is no Zika infection seen in humans yet, the state health department is awaiting the test results of three persons suspected with typical symptoms of Zika. Mosquito control measures are on.