Mosquitoes are by far one of the deadliest species on earth. Mosquito borne diseases are estimated to affect more than 700 million people globally every year. Millions eventually die from a deadly sweep of diseases like dengue fever, yellow fever, meningitis, Japanese encephalitis and many more that mosquitos carry.
To this long list of fatal infections, the Zika virus has reappeared with a cruel scream. The Zika virus is carried by the Aedes aegypti mosquito that incidentally is also an agent for dengue fever, yellow fever and chikungunya. The disease does not cause fatalities in humans but is linked to microcephaly (abnormal smallness of the head, a congenital condition associated with incomplete brain development) in babies.
Weather however has a significant role in the procreation of Aedes aegypti and subsequently the Zika virus. Aedes aegypti evidently thrives on heat, the hotter the better. Higher temperatures urges mosquitos to feed more often that is to sting more humans. This increases the probability of the vector (carrier of pathogens), mosquitos in this case; to acquire the Zika virus (pathogen) manifold. The mosquito also reproduces more under warm weather conditions. This further enhances the chance of propagation of the dreadful disease.
Moreover, warmer air also incubates the virus faster. This gives substantial time to the short lived mosquitos to receive the virus infection and to spread it to more humans. The average life of a mosquito spans 10-12 days.
El Niño, the usual suspect for all awful things attributable to weather these days, is also a reason behind the epidemic in Brazil. The Zika virus struck Northeast Region of Brazil is reeling under a drought and the region's largest city Recife witnessed the hottest September-October-November on record. The temperatures were almost 1.2 degrees Celsius higher than normal as per NASA data.
Scientists however agree that it is too early to blame any single weather event or even climate change for the recent outbreak of the Zika virus.
Almost 1.5 million cases of Zika have been reported worldwide with thousands of microcephaly instances. The virus was first documented in Uganda in 1947 and remained isolated to Africa for decades. The virus arguably travelled to Brazil with a tourist during FIFA World Cup. The World Health Organization (WHO) predicts that 4 million people will be affected around the world in 2016.
While the country is advancing towards warm weather as winter loosens its grip, citizens should take precautions against mosquito breeding and bites. Though there are no cases reported in India yet, the country remains at risk as the carrier mosquito, the Aedes aegypti is ubiquitous. The government should also put a robust Zika virus screening for travellers from other countries.
Meanwhile, Bharat Biotech, an Indian pharmaceutical company claims to have developed a vaccine for the deadly disease.
Columnist
Indranil is a weather industry expert with a decade long experience in the domain. He has been instrumental in setting up novel weather services across landscapes for both agriculture and industry, raising capital and crafting a growth story for weather forecasting in India. Currently he is Senior Vice President of Express Weather.
