“In this information age, everything about the [Zika] virus is known. But the disparate information needed to be analysed and made sense of for the lay reader. That is why we did this book.” - Dr Kalpana Swaminathan Co-author, The Secret Life of Zika Virus
“The mosquito, Aedes aegypti, has evolved beautifully. Just like us, it now works through the day, biting us in our normal work hours and not in the night.” - Dr Ishrat Syed Co-author, The Secret Life of Zika Virus
“Many gaps in our understanding of the virus and its link with neurological illnesses such as microcephaly exist in India.” - Dr Soumya Swaminathan Director general, Indian Council of Medical Research
One evening in late May, the World Health Organization reported that the Union health ministry had confirmed three cases of Zika virus disease in Bapunagar area of Ahmedabad district, Gujarat. What confounded many people across the country was why had the government kept this information secret. Over the next few days, the virus hogged headlines—the Centre came out with a clarification and the media exposed the gaps in the country's disease surveillance programme and traced the history of the Zika virus in the country. But, still there were more questions than answers. For instance, why and how did the virus that had been in India since 1953 suddenly become a cause for concern? Was India, like Brazil that had an outbreak of Zika in 2015, heading towards a Zika epidemic?
But, more than a year before the WHO report, two Mumbai-based paediatric surgeons had all the answers, which can be found in their latest book, The Secret Life of Zika Virus. “In this information age, everything about the virus is known. But the disparate information needed to be analysed and made sense of for the lay reader. That is why we did this book,” says Dr Kalpana Swaminathan, who, together with Dr Ishrat Syed, has been writing on several subjects including science, literature and language for two decades now. The duo writes under the pseudonym Kalpish Ratna. “Literally, the word is an anagram of our names; Kalpana means imagination, Ishrat means pleasure. So, we define 'Kalpish Ratna' as the pleasures of imagination,” they say.
In this treatise, the surgeons—known for their distinct narrative style that helps the reader follow complex science—trace the genealogy of the virus, known to cause microcephaly, and that of its vector, the mosquito (Aedes aegypti) through several continents. The book, say the authors, took them a year and a half of research, trudging through several scientific accounts, and the end result is a fascinating account of the trajectory of the virus.
Zika, the authors write, was discovered in Uganda's Zika forest by scientists from the Rockefeller Foundation studying yellow fever. Yellow fever had gripped the Americas through the first half of the 20th century, and in the second half, the focus had shifted to Africa.
In 1947, the year India gained independence, Zika virus was discovered in Africa, and soon it was found in India, too, says Ishrat. Since then, the virus has remained a mystery of sorts, escaping disease surveillance programmes, especially in India. “Many gaps in our understanding of the virus and its link with neurological illnesses such as microcephaly exist in India,” says Dr Soumya Swaminathan, director general, Indian Council of Medical Research. The ICMR has tested 50,000 people and also the Aedes aegypti. While four people have tested positive for Zika, the virus has not been isolated from any of the mosquitoes, says Soumya.
Dr Devendra Mourya of the National Institute of Virology (NIV), Pune, says though Zika virus was first demonstrated in India in the 1950s, there have been no systematic studies done after that. “Zika was never in the forefront of pathogenic viruses, but an ubiquitous agent as seen globally,” he says. “The first cases, detected from mild outbreaks in French Polynesia and subsequent evolution of the human disease profile of Zika as shown in Brazil, have been enigmatic.”
The fact that Zika has been found to have cross-reactivity with dengue virus, driving antibody dependent enhancement—those who have antibodies for dengue virus are more prone to Zika infection—has further complicated matters, says Soumya. “Besides, unlike other viruses which are only transmitted through one route, that is, the vector route, Zika is passed on through the mosquito as well as sexually. This is akin to blood-borne diseases such as HIV, except that in this case, the virus stays in the semen shorter than it does in the case of HIV,” she says. The sexual transmission has not been studied enough, write Kalpana and Ishrat in their book.
The Zika outbreak has been a spillover of the H1N1 (swine flu) and Ebola outbreaks in Asia and Africa, respectively. Ishrat points to the “apartheid” in scientific research, saying, “No one blinks when thousands of Indians or Africans die. But the death of one white man is considered a tragedy.”
But viruses, says the book, are difficult subjects to study—they mutate very fast and jump hosts (from mosquitoes to animals to human). Also, while they are not dangerous when inside their animal hosts, the same cannot be said about their residence in the human body. For instance, the Japanese encephalitis virus (JEV) lives comfortably inside a pig and doesn't cause any disease. That, however, is not the case when it enters the human through the mosquito.
“Unlike in humans, where 35 years is considered one generation, the virus mutates every two minutes,” explains Ishrat. The answer to why the virus causes diseases in humans and not animals, and more importantly, why is it doing so now is at the heart of this book.
“What would you do if your house was destroyed and you were thrown out? You would try to find a new place, wouldn't you?” asks Ishrat. The story of Zika is similar—a disruption of the evolutionary bargain between the host and its parasite. “You kill the pig, and the virus loses its home. It then proceeds to find a new home, and that is the human,” he says.
Environmental assault, such as the cutting of trees in the Brazilian rainforest, also robbed the mosquito of its home, allowing it to find residence in crowded cities. “The mosquito, Aedes aegypti, has evolved beautifully. Just like us, it now works through the day, biting us in our normal work hours and not in the night,” says Ishrat.
In 2011, Kalpana and Ishrat had written a piece for a magazine explaining the trajectory of the JEV and its relation to the pig slaughter industry in Gorakhpur, where, recently, more than 70 children died in a hospital. JEV, however, is no more the cause of deaths due to encephalitis in that region, says Soumya, who is also secretary, department of health research, ministry of health and family welfare.
For Kalpana and Ishrat though, what is pertinent is that children are still succumbing to fatal encephalitis every year. “The truly horrifying aspect of this Gorakhpur tragedy is the abysmal ignorance and persistent apathy with which we ignore facts that stare us in the face,” says Kalpana. “Does it really matter whether it is JEV or an unknown virus? The confluence of drivers that make the disease emerge are conspicuous for all to see on the streets of Gorakhpur.”
Environmental assault, rampant urbanisation, lack of proper sanitation and poor nutrition lie at the heart of the debate about emerging diseases, the couple insist.
And, Zika is one of those emerging diseases. It is now known that the Zika virus strain was a milder one in India compared to Brazil. Despite that, disease surveillance programmes are being stepped up, says Soumya. At NIV, different aspects of Zika virus are being studied, but Devendra says at this point, dengue and chikungunya are bigger threats in India.
Ishrat and Kalpana, however, don't agree, and say that policy makers need to act before the disease turns into a bigger threat like dengue and chikungunya. “We are a nation that doesn't care for its babies. Even if one baby gets microcephaly, it is bad enough,” says Kalpana.
Also, a vaccine for Zika is on the anvil. But viral illnesses, say the authors, can be best fought by the body's own defence. “Better nutrition means better immunity,” they say. Preventing diseases by safeguarding the environment, they say, is the more intelligent strategy.