New Delhi, Jul 3 (IANS): Amid the rise in Zika virus cases in Pune, the Centre, on Wednesday, issued an advisory to all states asking them to step up vigil.

Zika virus disease (ZVD) is a mosquito-borne disease transmitted by Aedes mosquitoes. While it is usually mild to moderate disease in adults and requires no specific treatment, in pregnant women, it may cause microcephaly -- a condition in which the head is significantly smaller due to abnormal brain development -- in the foetus.

Maharashtra has reported eight cases of Zika virus till July 2. Of these, six are from Pune, one each from Kolhapur and Sangamner, and 2 are pregnant women.

"In view of some reported cases of Zika virus from Maharashtra, Dr Atul Goel, Director General of Health Services (DGHS), has issued an advisory to states highlighting the need for maintaining a state of constant vigil over the Zika virus situation in the country," the Health Ministry said.

The ministry urged states "to instruct the health facilities in the a?ected areas or those catering cases from a?ected areas to screen the pregnant women for Zika virus infection."

The health workers must also "monitor the growth of the foetus" of Zika-positive women and "act as per Central government guidelines," the ministry said.

It also asked health facilities and hospitals to identify a nodal officer to monitor and act to keep the premises free of Aedes mosquitoes.

Besides, the advisory called on states to "strengthen entomological surveillance and intensify vector control activities in residential areas, workplaces, schools, construction sites, institutions, and health facilities."

Currently, Zika testing facilities are available at the National Institute of Virology (NIV), Pune; the National Centre for Disease Control (NCDC), Delhi; and a few selected virus research and diagnostic laboratories of the Indian Council of Medical Research (ICMR).

The ministry will continue to monitor the situation closely, the advisory noted.