Zika spread: India still relaxed in face of more violent, mutated virus version

India first saw an outbreak of chikungunya, zika’s cousin, in the mid 60s. Chikungunya then went off the radar, only to return in 2002 in a more violent form. Similarly with Zika, which is already present in India, is preparing for a Round 2 of assault. Experts suspect it to be a mutated and more virulent version of the virus that has swept the globe. Is India prepared?

Zika mutations after its travel around the world

Zika could complete its trip around the planet by spreading to vulnerable areas of the ‘Old World’–Europe, the Middle East, and Africa–Peter Hotez, the dean of the National School of Tropical Medicine, at Baylor College of Medicine in Houston, USA, told IndiaSpend via email, explaining Zika’s march.

 Along the way, Zika changed its character, from a relatively small virus causing fever, malaise, skin rash, conjunctivitis (red eye), muscle and joint pain and headache, according to this review paper published in the International Journal of Infectious Diseases, to one that causes neurological disorders such as microcephaly and the Guillain Barré syndrome (GBS), a temporary paralysis that can sometimes result in choking and death.

The scary part about the new Zika strain, Prof Hotez said, is its ability to infect pregnant women and the unborn foetus to cause microcephaly, which leaves infants with not just distorted features but stops the growth of the brain.

T Jacob John, 81, a professor emeritus of the Christian Medical College, Vellore, and one of India’s most experienced virologists believes the zika virus detected in India to be the old strain, which is “nothing to worry about”.

But, he warned, it is a matter of time before India faces zika’s mutated avatar. “We must expect that the mutated zika will come home to Asia,” T Jacob John told IndiaSpend in an email interview. “The question is not ‘if’ but ‘when’? We have been warned with sufficient lead time to get prepared. But, have we been preparing? I have seen no sign.”

Here are some excerpts from the interview to IndiaSpend where Professor John tells you what you need to know

Q. Of late zika cases recorded globally have either been travel-related, meaning the patient had travelled to an area where zika is endemic, or locally-acquired cases, where the infection was picked up from the community. India’s first zika case was local, based on a WHO update that says the woman had not travelled in the three months prior to acquiring the infection. What does the local acquisition of the disease imply?

If a traveller is found infected, the transmission occurred where he or she travelled from. Whereas, the local acquisition of zika signals four elements—one, the infected donor; two, the local presence of the virus; three, the transmission vector, the Aedes mosquito; and four, a susceptible set of people. If infected mosquitoes are imported, say through baggage or incoming aircraft, the infected donor need not be present. The local acquisition of zika implies that an outbreak has already been seeded. Its implication is the potential for further spread.

Q. India first saw an outbreak of chikungunya, zika’s cousin, in the mid-sixties. Chikungunya then went off the radar, only to return in 2002. Did it return in a more virulent form? If so, is this a good indication that zika is likely to evolve in India? How might it evolve?

Yes, the chikungunya that struck India in 2002 was a mutated version, just as the zika that struck the Americas in 2015 was a mutated version of the benign infection we have known. Actually, the virulent Latin American version began in the Pacific Islands in 2007.

• Zika has mutated possibly in its NS1 gene to become a virulent virus exquisitely efficient in reproducing in host cells and in the host organism—and hence spreads faster from man to mosquito to man.  

• Essentially, both chikungunya and zika have evolved to be more easily transmitted and more pathogenic. They present very similar behaviour. So, we must anticipate an outbreak of more virulent zika in India as well.

• As for exactly what evolved form of zika India will see, or how zika will evolve next, that is beyond prediction.

Q. What does India need to do to prepare for the eventuality of a zika outbreak? Given the limited laboratory testing facilities across the country, would we even get to know whether a patient has dengue, chikungunya or zika? And would that make a difference to how a patient is treated?

 

• Lab facilities and disease surveillance and so on are entirely man-made to fit the need. You may be interested and I may be too—but is the State (generic for governments at all levels) interested?

• A country that has no state programme to control dysentery, cholera, typhoid fever and a host of other infectious diseases that the enlightened world got rid of in the early 20th century, cannot have a programme to prevent and control viral diseases. You don’t go to middle school skipping primary school. If you do not have a programme to prevent and control, how important is it to know in the individual subject if it was dengue, chikungunya, zika or something else, such as leptospirosis, scrub typhus or enteric fever?

• Diagnosis helps identify treatable (diseases), like leptospirosis, scrub typhus, enteric fever, bacterial diseases, that must be treated very early to prevent death. There is no specific antiviral treatment for the zika virus infection. Dengue cases need follow up to identify if severe dengue develops, which necessitates urgent treatment.

• Can a country that does not “practice” “public health” suddenly put together all the pieces and create a public health infrastructure to prepare for zika outbreak? This fundamental question is exercising my mind at this time.

 

The original IndiaSpend article has been condensed to suit editorial purposes