Cattle samples collected from six villages around ground zero -- Kolat village in Sanand whose resident Amina Momin was the first human in India to get infected with CCHF and die on January 3 -- have tested positive for high viral load.
Speaking to TOI, director of Pune's National Institute of Virology Dr A C Mishra said, "20% of the samples from six villages show positive CCHF infection. This means the virus has been circulating for some time in India and has just recently been detected."
NIV has also picked up samples from rodents to check for the virus.
"We have to immediately cut transmission of the virus from ticks to cattle by intensifying operation pesticide, cleaning the cattle and their sheds. If even 50% of the ticks are destroyed from the body of the host, the transmission can be halted," Mishra added.
So does this mean the cattle infected have to be culled just like chicken were during the bird flu outbreak in India?
No, said Mishra. "Once the H5N1 virus infected poultry or birds, it killed them. That's how we knew where to look for the virus and killed all poultry around the site to stop transmission. In case of CCHF, the virus sits inside an animal's body but does not harm it. So we can't collect samples from all animals in Gujarat looking for the virus. Culling is, therefore, not recommended. We have to just break the cycle of the virus jumping from ticks to cattle," he added.
TOI had first reported how NIV last week found that a particular variety of ticks, Hyalomma, were carrying high quantities of CCHF virus in Ahmedabad, proving that the virus wasn't imported.
"Our main recommendation, therefore, is to reduce tick population which can circulate the virus in the environment for many years. They lay their eggs and transfer the virus into it. The egg hatches and continues to infect animals," Mishra added.
The CCHF virus is noted by the Union health ministry as a bio-safety level IV agent -- of maximum danger.
This is for the first time that India has reported human infection with CCHF by coming in direct contact with blood or other infected tissues from livestock. Human mortality rate is a high as 90%. The CCHF virus has been reported from Africa, the Balkans, West Asia and Pakistan.
"If the virus is present in the cattle, it could have spread from them as in villages, humans and cattle live in close proximity. Cutting meat infected with the virus or handling infected animal urine could lead to its spread to humans," Mishra added.