A 27-year-old person has tested positive for Zika virus in Tamil Nadu. This comes just a month after three cases were confirmed in Gujarat.
To most infectious disease experts, the arrival was not a matter of if, but when. Old samples stored at the National Institute of Virology in Pune indicated that Zika had been detected in India decades ago. But the new arrival of Zika is challenging for three reasons.
First, the vector that carries Zika and other arboviruses, the Aedes aegypti mosquito is far more prevalent in India now than in previous decades. This mosquito is responsible for the transmission of dengue and chikungunya and is poorly controlled in urban areas in India.
The surge in dengue cases in recent years across India is indicative of the serious threat that Zika poses across the country.
Second, the population at risk of 2.7 crore newborns each year means that even a small proportion affected could add up to a large number of cases.
Third, there is no vaccine or treatment for Zika which means that our ability to protect ourselves at an individual level is low.
What is the Root Cause?
At the heart of the problem is India’s poor performance on mosquito control. Preventive measures – such as the fumigation and insecticide spraying of local spaces – seem to be kicking in too little, too late.
Moreover, rapid urbanisation with poor planning and climate change are affecting the pattern of dengue, chikungunya outbreaks. Better surveillance is needed to track the changing trends of the vector.
Heavy rains during monsoons create a number of breeding sites and India’s densely populated cities, allow mosquitoes to thrive in close proximity to people.
Controlling Aedes aegypti breeding sites needs a coordinated response and not blame-shifting among local municipalities and health departments.
Increasing dengue cases and deaths have forced the Indian courts to take the matter into their own hands, sending a strong message to the Delhi government and municipalities recently, to step up action in the National Capital Region.
What Should Be Done?
Zika infections are usually asymptomatic or very mild, with only fever and non-specific symptoms. But when the virus infects pregnant women, it affects the unborn baby and causes congenital brain abnormalities in the newborn.
Unlike dengue, Zika can be transmitted through sexual intercourse. The immunity of the Indian population to the virus is also not fully understood.
Moreover, a number of countries have reported an unusual increase in Guillain-Barré Syndrome, a neurological illness coinciding with the Zika virus outbreak in the country.
With no treatment available for Zika, it is critical to prevent the proliferation of the mosquito populations that are able to carry the virus, in order to protect future generations. What the government must now do is increase surveillance and vector control efforts, not only in the state that has detected Zika but nationally.
Acknowledging the gravity of the threat of Zika is the first step towards its management and containment and is critical now more than ever.
On an individual level, repellants and long sleeved clothing can prevent transmission. Pregnant women, in particular, should protect themselves from mosquito bites and watch out for flu like symptoms such as a low-grade fever, headache,rash, itching, joint pains and body pains etc.
The introduction of Zika into the South Asia region could lead to unprecedented outbreaks of both the virus and neonatal abnormalities and as one of the most densely populated countries in the world with such a high birth rate, India is the perfect candidate for Zika to thrive and we have to stop it before it does.
(Professor Ramanan Laxminarayan is an infectious diseases expert. He is the Director at Center For Disease Dynamics, Economics & Policy. Anna Trett is a Research Analyst at the Center for Disease Dynamics, Economics & Policy.)
(This article was originally published on 1st June 2017. It is being reposted from The Quint’s archives after Tamil Nadu reported the first case of the Zika virus.)
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