India is one of more than 80 countries where the Zika virus is present, although the first confirmed cases were reported only last year. The initial two flare-ups of the virus, in the western state of Gujarat and the southern state of Tamil Nadu, involved just a handful of infections.
The current outbreak is considerably larger and for the first time, scientists found mosquitoes that were infected with the virus, indicating that it was being transmitted locally.
Until this outbreak, Indian health authorities had “never found [Zika] positive mosquitoes,” said Neena Valecha, director of the National Institute for Malaria Research in Delhi. “That is what was of concern.”
Health officials in the northern state of Rajasthan, where Jaipur is located, expressed confidence that the outbreak is under control. Of the 135 people infected through Thursday, 125 have recovered from their symptoms, they said. Approximately 40 pregnant women have been infected with the virus, and they will receive special monitoring.
Naveen Jain, health secretary for Rajasthan, said staff from his department were visiting the affected areas on a daily basis to screen for new cases, educate residents and eliminate breeding grounds for mosquito larvae. They are also engaging in “fogging” operations — the spraying of insecticide — to kill the adult mosquitoes that spread the virus.
“The positive cases are deteriorating very fast and the situation is under control,” Jain said.
Officials have divided the affected area into 10 zones and formed more than 300 teams to canvass the vicinity, added Veenu Gupta, additional chief secretary in the state’s health department.
Zika burst onto the global stage starting in 2015 when an unprecedented outbreak took place in South America, infecting hundreds of thousands of people. In Brazil, more than 1,000 babies were born with serious birth defects such as microcephaly, a condition where babies’ heads are abnormally small and sometimes their brains underdeveloped.
Subsequent research by the Centers for Disease Control has shown that about 1 in 10 women infected with the virus give birth to babies with grave birth defects — a figure that rises when the infection takes place in the first trimester.
While the large epidemic that gripped Latin America has subsided, “any act of transmission for us is a concern, especially in urbanized centers with a large population,” said Elizabeth Brickley, a Zika expert and professor at the London School of Hygiene and Tropical Medicine.
Brickley said that about 80 percent of the people infected with Zika show no symptoms, so the detected cases likely represent only a fraction of the actual circulation of the virus. What’s more, in a place like India, some people have already been exposed to a related mosquito-borne virus that causes Dengue fever — and those antibodies can in turn lead to inaccurate test results for Zika.
Several vaccines for Zika are in development, but for now “avoiding mosquito bites is the best advice we have,” Brickley said.
The outbreak comes at an inopportune time for the tourism industry in Rajasthan, which is gearing up for the start of the high season. Every winter, millions of tourists from other parts of India and from around the world travel to Rajasthan and especially its capital, Jaipur, the focus of the outbreak.
The city is one of the stops on India’s famed “golden triangle” of tourist destinations that also includes Agra, home of the Taj Mahal, and Delhi, the nation’s capital. Kuldeep Ranka, principal secretary in Rajasthan’s tourism department, said that the outbreak is “effectively contained” and “it is not affecting tourism.”
Shastri Nagar, the neighborhood where the outbreak is centered, is a working-class area near Jaipur’s famous walled old city. Lalit Soni, 24, a local resident, said that a neighbor down the road, a doctor, was infected with the virus but recovered rapidly. Soni credited state health officials with playing a proactive role in tackling the outbreak through door-to-door visits and by cleaning ditches where standing water had gathered.
Divyanshu Maurya, 25, said that when news of the outbreak spread, his initial reaction was fear. When he himself fell ill with fever for two days, he worried that he might have Zika. (In the end, he did not.) Maurya, too, said that the government’s education and mosquito-eradication efforts had helped ease local worries.
Krishnaraj Singh Jasana in Jaipur contributed to this report.