After three adults tested positive for the Zika virus in Ahmedabad district, Gujarat in January this year, an adult male from Krishnagiri district of Tamil Nadu tested positive for the Zika virus . This is the first case of Zika from Tamil Nadu.
According to the State Health Secretary J. Radhakrishnan, the patient reported with fever and other symptoms generally associated with Zika infection and was treated as an outpatient at a remote primary health centre at Natrampalayam panchayat.
"His samples were first tested for dengue and Chikungunya but they turned negative. So we tested his blood and urine samples for Zika and they tested positive. We sent his urine samples to NIV (National Institute of Virology, Pune) and reconfirmed Zika infection. He has completely recovered and is doing well," Mr. Radhakrishnan said.
"He has no travel history to countries or places where Zika virus disease is currently prevalent. Preliminary investigation reveals that no one from his immediate family has travelled to any country where Zika virus is in circulation. We think it is due to local transmission," Mr. Radhakrishnan says.
According to him, his wife had delivered three months ago and tested negative for Zika.
Unlike the three cases in Ahmedabad, the patient has been counselled. "The patient has been given counselling. We have particularly counselled him about the transmission of the virus through sexual activity," he says.
According to a report in The Hindu , approximately 200 suspected cases of the virus were tested at King Institute of Preventive Medicine and Research, Chennai, and this is the first one that tested positive.
"There seems to be low-level transmission of Zika virus in India. We have tested nearly 40,000 samples so far but picked up only three cases in Ahmedabad and now one in Tamil Nadu," said Dr. Soumya Swaminathan, Director-General of the Indian Council of Medical Research (ICMR). "It is possible that we may pick up more cases from different parts of the country, which would indicate that the virus is present in India." Zika virus was first reported in India in the 1950s.
"We don't know why the Zika virus has not caused the same problems like microcephaly in newborns and Guillain-barre syndrome in adults as seen in Brazil. It could be because the virus is different or due to host immunity [people already exposed to the virus and have developed immunity to the virus] or other factors. These are not fully understood," Dr. Swaminathan said. "It is early stage to speculate about the epidemiology and disease profile of Zika," she added.
Screening for birth defects and microcephaly in newborns and Guillain-barre syndrome has just started. "A year from now we will have more data," Dr. Swaminathan said.