HYDERABAD: In a cause for concern, the Asian strain of zika virus has mutated, the scientists have confirmed. It’s only last month that the World Health Organisation (WHO) had confirmed the presence of zika virus in India . Virus mutation has come as a major challenge to health planners and scientists, who are involved in zika research.According to Hyderabad doctors, zika virus has been most possibly present in the country for decades, but due to lack of diagnostic facilities at the local level, the disease has gone undetected. Now that the WHO has confirmed the presence of zika virus in Hyderabad, they warn that a strong surveillance is needed to prevent the spread of the virus, particularly in the backdrop of research reports that the Asian strain of zika has mutated.“We have not yet developed widely accessible tests for zika infection. We may, at times miss out the coinfection due to low index of suspicion and poor availability of diagnostic tests,” said internal medicine expert Dr Aftab Ahmed of Apollo Hospitals, Secunderabad, while emphasizing the need for a close watch on the virus and its mutants.As the common mosquito, Aedes aegypti, has its presence in India, there is every possibility of the zika coinfection with dengue and/or chikungunya. “Though each infection has some characteristic symptoms of its own, there may be some overlapping of symptoms, posing diagnostic dilemma to doctors,” Dr Aftab Ahmed added. The problem will be compounded if the virus has mutated.Quoting research on zika virus in China, the Centers for Disease Control and Prevention CDC ) of the USA in its recent report says a mutation has occurred in the Asian-lineage zika strain. At present, this mutation has made it more infectious to mosquitos. It is not clear whether the mutation will also cause more infection in the human host.Researchers from Colorado State University , in a study, reported that the clinical impact of Aedes aegypti mosquito carrying three viruses is “unclear”. And this makes zika virus more troublesome for doctors in Hyderabad, where diagnostic facilities for this virus are not commercially available.Doctors have also found that dengue, chikungunya and zika viruses have developed a “friendly tendency” within the midgut of the mosquito. Normally, when more than one virus exists in a vector, they compete and only one of them emerges stronger. But in the case of these three viruses, there was no competition and all of them found a comfortable stay in the mosquito. This, in other words, could mean dual or triple infection in a single mosquito bite.