Is Zika’s Initial Outbreak Pattern in India Adding Up to the Beginning of Something Bigger

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posted on 5 years ago — updated on 1 second ago

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The bulletin points out that prior to the Rajasthan and MP outbreaks last year, there were three Zika virus cases in Ahmedabad in 2016 and 2017, the first in the sub-continent. Low levels of population immunity may therefore be expected, the bulletin states.

Epidemiologists across the world are concerned about the question of whether India’s Zika outbreak in Rajasthan and MP and detection in Ahmedabad and Chennai is part of a pattern of smaller localised outbreaks or the beginning of something bigger.

This concern culminated after a recent World Health Organisation (WHO) bulletin on the Zika virus disease in India. The bulletin points out that prior to the Rajasthan and MP outbreaks last year, there were three Zika virus cases in Ahmedabad in 2016 and 2017, the first in the sub-continent. Low levels of population immunity may therefore be expected, the bulletin states.

Zika virus is a mosquito-borne flavi virus that was first identified in Uganda in 1947 in monkeys. It was later identified in humans in 1952 in Uganda and the United Republic of Tanzania. Zika virus disease is caused by a virus transmitted primarily by Aedes mosquitoes, which bite during the day.

Symptoms are generally mild and include fever, rash, conjunctivitis, muscle and joint pain, malaise or headache. Symptoms typically last for 2–7 days. Most people with Zika virus infection do not develop symptoms.

The WHO bulletin quotes Dr Neena Valecha, director of the National Institute for Malaria Research in New Delhi, “The situation is a matter of concern.” However, she is hopeful that the government’s vigorous response, and increased surveillance will be sufficient to track and reduce transmission to a minimum.

Zika virus’s risks of causing microcephaly in newborns will be an important focus of India’s Zika response in the coming months, the WHO bulletin states. Microcephaly is a condition in which the head is smaller (circumference) than normal.

Outbreaks of Zika virus disease have been recorded in Africa, the Americas, Asia and the Pacific. From the 1960s to 1980s, rare sporadic cases of human infections were found across Africa and Asia, typically accompanied by mild illness.

The first recorded outbreak of Zika virus disease was reported from the Island of Yap (Federated States of Micronesia) in 2007. This was followed by a large outbreak of Zika virus infection in French Polynesia in 2013 and other countries and territories in the Pacific. In March 2015, Brazil reported a large outbreak of rash illness, soon identified as Zika virus infection.