One male adult and two women tested positive for Zika virus. Babies born to both the women do not have microcephaly

The dreaded Zika virus has finally reached the Indian shores. On May 15, the Ministry of Health and Family Welfare reported to the World Health Organisation three laboratory-confirmed cases of Zika virus disease in Bapunagar area, Ahmedabad District, Gujarat. “This report is important as it describes the first cases of Zika virus infections and provides evidence on the circulation of the virus in India. These findings suggest low level transmission of Zika virus and new cases may occur in the future,” says a report of the World Health Organisation.

While one case was detected through routine laboratory surveillance carried out at B.J. Medical College, Ahmedabad, Gujarat, two additional cases were identified through the Acute Febrile Illness (AFI) and the Antenatal clinic (ANC) surveillance.

None of the three people — two in women and one in a 64-year-old male — who was infected by the virus had travelled to any country where Zika virus transmission is currently going on. “This indicates the local transmission of Zika virus in the country,” says Dr. Soumya Swaminathan, the Director-General of the Indian Council for Medical research (ICMR), Delhi.

Though both the women who were infected with the virus were pregnant, the babies do not have microcephaly (small head). One of the women who tested positive for Zika virus is 34 years old who was admitted at a hospital for delivery.  She developed a low grade fever after delivery and had no history of fever during pregnancy. As a result, she delivered a clinically healthy baby on 9 November 2016, says a report of the WHO.

The other woman, who is 22 years old, tested positive for Zika virus in her 37^th week of gestation. Since she was not infected during the first trimester, the baby did not suffer from microcephaly.

“As per protocol, the spouses of both the women were tested for Zika virus but did not test positive,” says Dr. Swaminathan. “After the detection of the cases a lot of vector control measures were undertaken.” Zika virus is transmitted to people through the bite of an infected mosquito called Aedes Aegypti. This is the same mosquito that transmits dengue and chikungunya and is very common in India.

“The surveillance for Zika virus had started last year in June-July. The detection of these cases is a reassurance that the surveillance system is working well. We are continuing with the surveillance system,” Dr. Swaminathan says.

“Efforts to strengthen surveillance should be maintained in order to better characterize the intensity of the viral circulation and geographical spread, and monitor Zika virus related complications,” says the WHO.

Besides Pune’s National Institute of Virology and NCDC in Delhi, ICMR has strengthened 25 laboratories for Zika virus diagnosis. In addition, three entomological laboratories are conducting Zika virus testing on mosquito samples.

“ICMR has tested 34,233 human samples and 12,647 mosquito samples for the presence of Zika virus. Among those, close to 500 mosquitos samples were collected from Bapunagar area, Ahmedabad District, in Gujarat, and were found negative for Zika,” says the WHO report. “The Rashtriya Bal Swasthya Karyakram (RBSK) is monitoring microcephaly from 55 sentinel sites. As of now, no increase in number of cases or clustering of microcephaly has been reported from these centres.”