As the zika virus threat looms over the national capital, the All India Institute Medical Sciences (AIIMS) has tested at least 100 samples of patients with “acute febrile illness” as part of its surveillance measures. Zika virus, like dengue and chikungunya, is caused by the same vector – the Aedes mosquito.
AIIMS officials confirmed that at least 100 samples have been tested between December and June and that “no sample has been tested positive so far”. Officials added that at least “5-10 samples” have been tested each week.
On May 27, the World Health Organisation had confirmed India’s first cases of the Zika virus. The health ministry reported that of the three cases — all from Bapunagar area of Ahmedabad — one was that of a pregnant woman.
With the arrival of the monsoon in the capital and the possibility of another mosquito-borne infection outbreak, AIIMS officials said they “will increase the number of samples being tested for Zika virus during peak season”.
As of now, the Integrated Disease Surveillance Programme (IDSP) is tracking the clustering of acute febrile illness in the community. In addition to the National Institute of Virology, Pune, and National Centre for Disease Control (NCDC) in Delhi, 25 laboratories have also been strengthened by the Indian Council of Medical Research (ICMR) for laboratory diagnosis.
Three entomological laboratories are also conducting zika virus testing on mosquito samples. Dr Lalit Dar, Professor, Department of Microbiology, AIIMS, said, “We are currently not part of the ICMR network. Since we have the capability — as a part of the surveillance exercise — we have tested at least 100 samples for Zika virus… Surveillance will be further increased at AIIMS once cases of dengue and chikungunya show a likely increase during peak season. The exercise is being undertaken as there is potential threat.”
Officials added that they have tested “preserved samples” of patients with zika-like symptoms. “We have also tested preserved samples, where patients had symptoms similar to zika infection. However, the surveillance is random to ensure proper monitoring,” an official said.
Another official said, “The clinical representation of Zika virus is similar to that of dengue. The primary challenge is to ensure that the three infections are correctly diagnosed as they show similar symptoms. But detecting Zika is more challenging as 80 per cent cases are asymptomatic.”
As of now, AIIMS has procured real-time PCR kits to detect the three infections.
During the last chikungunya outbreak in the capital, AIIMS reported cases where patients suffered from both dengue and chikungunya.
In the recent past, cases have been reported where co-infection of dengue, chikungunya and Zika has been detected. Co-infection of Zika virus has already been reported in other countries — with dengue and chikungunya in Colombia and with dengue in French Polynesia and New Caledonia.