Why should a recent outbreak of a nosebleed-causing fever in Iraq worry us back in India? That’s because the Crimean Congo Haemorrhagic Fever (CCHF) has claimed 19 lives, according to the WHO, and it has been detected here in the past.
While India has been considered a hotspot for many emerging and re-emerging infectious diseases, Dr Samiran Panda, additional Director-General, Indian Council of Medical Research (ICMR), told The Indian Express that the Government was fully prepared to deal with any possible outbreak. The Pune- based Indian Council of Medical Research and the National Institute of Virology (ICMR-NIV) have done extensive research and surveillance in humans, animals and ticks to understand the disease burden and transmission dynamics, he added.
HOW IS INDIA PREPARED
The fever is caused by a zoonotic virus, which, owing to its wide distribution and infectivity, can lead to high mortality rates. “Since 2011, the laboratory screening of CCHF for humans, animals and ticks has been under way. A state-of-the-art containment BSL-4 facility of ICMR at Pune in 2012 made it possible to quickly develop indigenous serological assays for diagnosis of IgM and IgG for humans and IgG for the livestock. These indigenous technologies not only helped in timely diagnosis of suspected CCHF cases but also in surveillance of CCHF in human, livestock and ticks in the country,” senior ICMR scientists said.
WHAT IS THE VIRUS BEHAVIOUR?
CCHF was first identified in 1944 in the West Crimean region of the former Soviet Union. The virus was subsequently isolated in 1956 from a human carrier. It is a member of the genus, Orthonairovirus, family Nairoviridae. The average case-fatality rate is 30–50 per cent. This varies between 5 per cent and 80 per cent in various outbreaks. Humans contract it through infected tick bites or by coming into contact with infected blood or animal carcasses. The secondary infection in humans is due to close contact with secretions of the CCHF-infected patient, including blood, vomit, stool, urine and fluids.
The incubation period is short (3–14 days). The pre-haemorrhagic period is characterised by the sudden onset of fever, headache, myalgia,dizziness and further symptoms of pain in abdomen, diarrhoea, nausea and vomitting.
As far as cases from Iraq are concerned, severe bleeding, both internally and externally, especially from the nose, was observed among two-fifths of the deceased. These are typical symptoms of CCHF cases irrespective of the geographical region, Dr Panda said.
There is no specific treatment for CCHF. “Since no specific treatment is available, supportive treatment includes maintaining fluid and electrolyte balance, monitoring and replacement with platelets, fresh frozen plasma and erythrocyte preparations,” say scientists.
PREVIOUS INDIA SPREAD
Since it was first detected in Gujarat in 2011, a total of 128 cases and 54 deaths (CFR- 42 per cent) were reported from that state and Rajasthan. A survey by health authorities in Gujarat had then revealed a high proportion of the animal population positive for anti-CCHF IgG antibodies from 15 districts. This finding further led to studies to ascertain if there was a recent import/mutation of the virus.
According to a report, “Experiences of ICMR with tick-borne zoonotic infections,” published in the Indian Journal of Medical Research (March 2021), authors Dr D T Mourya, Dr Pragya Yadav and others found the virus existed consistently for 30 to 40 years as the ICMR-NIV continued molecular clock studies on various strains isolated from humans and tick vectors. The high prevalence of this virus in Gujarat between 2011-2014 resulted in 34 CCHF cases and 16 deaths. In 2014, samples from a suspected Viral Haemorrhagic Fever (VHF) patient from Veravilapur village, Sirohi district, Rajasthan, confirmed the spread of CCHF.
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The ICMR-NIV team developed an indigenous kit for detection of CCHF antibodies in humans and animals. Scientists further tried to understand the prevalence of the disease and conducted a countrywide survey with the Indian Council of Agricultural Research (ICAR). It detected antibodies in samples from bovine, sheep and goats from 22 states and one Union Territory. The results showed the prevalence of the virus in all these areas.
In 2016, an Indian migrant worker, who returned from Muscat, Oman to Kutch, Gujarat, became the first imported CCHF case and carried a strain belonging to the Asia-1 IV group mingled with strains from Oman, Afghanistan, Pakistan and Iran. Another imported CCHF case from Dubai was identified in Thrissur, Kerala. In 2019, a maximum number of CCHF cases were detected in Gujarat and Rajasthan with a 50 per cent case fatality rate.