Zika: One more reason for zero tolerance towards mosquitoes
Is zika here to stay? More than 110 people have tested positive in Jaipur’s Shastri Nagar and Sindhi camp neighbourhoods over the past one month, raising fears of the viral infection becoming endemic to cause annual outbreaks.
There are reasons for concern. For one, the environmental conditions in India are conducive not just for the virus to thrive, but also the mosquito that spreads it.
Zika is a mosquito-borne virus that belongs to the flaviviridae family, which includes dengue and Japanese encephalitis (JE) viruses.
It thrives in tropical conditions and causes disease in the Pacific islands, Africa, South America and south and southeast Asia.
The disease is spread by the aedes aegyti mosquitoes, which also spreads dengue and chikungunya. So a zika outbreak can potentially occur in all the places that have reported dengue or chikungunya.
What’s as worrying is the likelihood of zika being missed or misdiagnosed even in clinical settings because around 80% of those infected have no symptoms and those who fall ill have mild and non-specific symptoms.
Zika infection may cause fever, rash, joint and muscle pain, headache and conjunctivitis (red, itchy eyes), with the symptoms typically lasting two to seven days. The treatment is symptomatic and there is no vaccine. It has caused no deaths. Ninety-one of the 109 infected people in Jaipur have recovered.
NEW MUMS AT RISK
Zika virus infection was not an issue of public health concern until the infection in pregnant women was linked with microcephaly, a birth defect in which the baby’s head is smaller than normal because of abnormal brain development.
Pregnant women who get infected also risk their unborn baby, having a stillbirth or preterm birth. In adults and older children, it can cause neurological disorders including Guillain-barré syndrome (GBS), and myelitis (spinal cord inflammation causing paralysis and sensory loss).
With 26 million births each year and one in five (21.1%) of the deliveries still happening outside a health centre or hospital, hundreds of thousands of babies will be at risk of microcephaly and neurological abnormalities if the infection takes root in India.
Zika was first identified in monkeys in Uganda in 1947 and in humans in Uganda and Tanzania in 1952.
From the 1960s to 1980s, caused mild fever across Africa and Asia, but the 2015-16 outbreak in Brazil and South America linked the infection to microcephaly in newborns and GBS, which promoted WHO to declare the zika a Public Health Emergency of International Concern on February 1 to November 23, 2016.
Zika has been reported in 86 countries, with the first confirmed case in India in Gujarat in February, 2017, when three people tested positive in Ahmedabad, which was followed by one case in Krishnagiri district in Tamil Nadu in July of the same year.
ISOLATION AND FUMIGATION
The first zika case in 2018 was identified when an 85-year-old woman hospitalised with fever at Sawai Man Singh Hospital in Jaipur was screened for zika after she tested negative for influenza, dengue, malaria and chikungunya. The Indian Council of Medical Research’s newly set-up Virus Research & Diagnostic Laboratories (VRDL) that conducted the tests immediately raised red flags and everyone with fever within a 3-km radius of her home in the densely-populated Shastri Nagar neighbourhood was tested for zika and treated in isolation in a mosquito free zone to prevent the infection from spreading further.
The upside is people with mild or no symptoms are not as infectious as those with symptoms, so rapid testing and isolating people with symptoms till they recover completely can contain the infection, as will fumigating to destroy all adult mosquitoes and cleaning larvael breeding sites. Breaking the short one-week incubation period of the virus is the way to stop infection.
That’s how Brazil did it. And that’s what we need to do to keep the future generations safe.