Crimean-Congo hemorrhagic fever virus in Central, Eastern, and South-eastern Asia.

Crimean-Congo hemorrhagic fever (CCHF), caused by Crimean-Congo hemorrhagic fever virus (CCHFV), is endemic in Africa, Asia, and Europe, but CCHF epidemiology and epizootiology is only rudimentarily defined for most regions. Here we summarize what is known about CCHF in Central, Eastern, and South-eastern Asia. Searching multiple international and country-specific databases using a One Health approach, we defined disease risk and burden through identification of CCHF cases, anti-CCHFV antibody prevalence, and CCHFV isolation from vector ticks. We identified 2313 CCHF cases that occurred in 1944-2021 in the three examined regions. Central Asian countries reported the majority of cases (2,026). In Eastern Asia, China was the only country that reported CCHF cases (287). In South-eastern Asia, no cases were reported. Next, we leveraged our previously established classification scheme to assign countries to five CCHF evidence levels. Six countries (China, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan) were assigned to level 1 or level 2 based on CCHF case reports and the maturity of the countries' surveillance systems. Two countries (Mongolia and Myanmar) were assigned to level 3 due to evidence of CCHFV circulation in the absence of reported CCHF cases. Thirteen countries in Eastern and South-eastern Asia were categorized in levels 4 and 5 based on prevalence of CCHFV vector ticks. Collectively, this paper describes the past and present status of CCHF reporting to inform international and local public-health agencies to strengthen or establish CCHFV surveillance systems and address shortcomings.

Identification and analysis of Crimean-Congo hemorrhagic fever virus from human sera in Tajikistan.

BACKGROUND: Crimean-Congo hemorrhagic fever (CCHF) is a virulent tick-borne disease reported in more than 30 countries across Europe, Africa, and Asia. The disease is considered endemic in several Central Asian countries, including Tajikistan; however reports of human cases from these regions rarely reach the West. METHODS: We analyzed all historical confirmed cases of CCHF in Tajikistan, mapping these reports against geographic data to assess risk areas. In addition, comprehensive analysis was undertaken on the 2010 human CCHF cohort to demonstrate effective methodologies for diagnosing this disease in-country. RESULTS: These data show that CCHF is endemic in Tajikistan, and several large clusters have been recorded. Endemic foci of disease are localized to the southern region, with geographical factors such as altitude, monthly mean temperature, and monthly mean precipitation levels limiting establishment of tick vectors in other areas. Genomic analysis of viral RNA from a 2010 human case revealed high nucleotide homology (99%) to a strain isolated in Tajikistan in 1990. CONCLUSIONS: CCHF is an important vector-borne and nosocomial pathogen in Tajikistan. The ability to rapidly detect cases using real-time RT-PCR shortly after admission in the hospital setting allows prompt implementation of barrier nursing techniques, therefore reducing onward transmission of the virus.

Crimean-Congo hemorrhagic fever in Tajikistan.

Crimean-Congo hemorrhagic fever (CCHF) is a pathogenic tick-borne disease caused by a single-stranded negative-sense RNA virus classified within the Nairovirus genus of the family Bunyaviridae. Cases of CCHF have been registered in Tajikistan since the disease was first brought to medical attention in 1944. However, historical Tajik manuscripts describe the features of hemorrhagic fever associated with ticks, indicating that the disease might have been known in this region for many years before it was officially characterized. Here we review the historical context of CCHF in Tajikistan, much of which has been described over several decades in the Russian literature, and include reports of recent outbreaks in Tajikistan.