Home / India News / Two lineages of Congo fever viruses present in Rajasthan: Study
A study, in the midst of an outbreak of Covid-19, has revealed that two different Crimean Congo hemorrhagic fever virus (CCHFV) lineages are circulating within the Hyalomma tick pools in Rajasthan. The study has also called for the need to enhance human, tick and livestock surveillance in other districts of Rajasthan and nearby states.
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Four human samples and thirteen Hyalomma tick pools were found positive for CCHFV positive and two different types of glycoprotein precursor (M) segments were observed in the tick samples, according to the study that was conducted by researchers at the National Institute of Virology; Indian Council of Medical Research, Department of Health Research (ICMR); National Centre of Disease Control; Sawai Man Singh Medical College-Jaipur; All India Institute of Medical Sciences-Jodhpur; State Disease Diagnostic Centre; Animal Husbandry-Jaipur and Dr SN Medical College-Jodhpur. The study was published in the journal Virus Research on June 4.
“CCHF is a zoonotic viral disease presenting with fever and hemorrhagic manifestations in humans. After several outbreaks of CCHF being reported from Gujarat since 2011 till 2019, and from Rajasthan in 2014 and 2015, the present study reports the CCHF outbreak which was recorded from five human cases in three districts Jodhpur, Jaisalmer, and Sirohi of Rajasthan state since August 2019 till November 2019,” the study read.
According to the findings, a high percent of positivity was recorded in the samples of livestock animals for the CCHFV IgG antibody. Human blood samples that were found positive for the CCHF virus (CCHFV) and Hyalomma tick pool samples were sequenced using next-generation sequencing method.
Two different M segment genotypes, encoding glycoprotein precursor, were identified from tick pools in the study - first from Asian and second from African lineage. The L gene (polymerase) and the S gene (nucleocapsid) clustered in the Asian lineage.
“We also observed 6% amino acid changes between the death and the survived case of CCHFV in the M gene. This report also sets an alarm to enhance human, tick and livestock surveillance in other districts of Rajasthan and nearby states. Biosafety measures, barrier nursing along with the availability of personal protective equipment and ribavirin drug will always be a mainstay in preventing nosocomial infection for proper case management,” experts suggested.
The study said that, “though no nosocomial or human-to-human transmission of CCHF or any infection amongst close contacts was reported in the outbreak of 2019, still it alarms the intense awareness campaigns and trainings amongst healthcare workers, animal handlers, and abattoir workers/farmers, veterinarians which will help in early reporting and quick diagnosis as well as reducing the spread of the disease.