Seroepidemiological and molecular investigations of infections with Crimean–Congo haemorrhagic fever virus in Kazakhstan

Abstract

The aim of this study was to detect the seroprevalence of Crimean-Congo haemorrhagic fever virus (CCHFV) in patients with fever of unknown origin (FUO) in endemic (Kyzylorda) and non-endemic (Almaty) oblasts of Kazakhstan. Methods: Paired serum samples from 802 patients with FUO were collected. Serum samples were investigated by ELISA to detect IgG and IgM antibodies against CCHFV. Sera with suspected acute infection were further investigated by RT-PCR to detect the viral RNA. Results: IgG antibodies were detected in 12.7% of the sera from both oblasts. Acute infection was shown by IgM ELISA in four patients from Kyzylorda, with only one developing severe CCHF. Viral RNA was found by RT-PCR in the other three patients' sera. Phylogenetic analysis of partial L and S segments revealed CCHFV genotype Asia 2 and a possible reassortment between the genotypes Asia 1/Asia 2. Animal husbandry, such as working with cattle and horses, was significantly associated with CCHFV seropositivity. Conclusions: The antibodies and viral RNA detected in sera indicate that mild or even asymptomatic CCHFV infections are presented in Kazakhstan. This study describes the circulation of CCHFV in the so far non-endemic Almaty oblast for the first time. In conclusion, physicians treating patients with FUO in Kazakhstan should be aware of mild CCHF.

Seroprevalence of Crimean-Congo hemorrhagic fever in humans in the World Health Organization European region: A systematic review

“…Russia and western Asia. Georgia shows a prevalence similar to that in eastern European countries (2.8%, [52]), while the Russian Federation (11.1%, [53]) and Kazakhstan (12.7%, [51]) show a prevalence closer to that found in Turkish areas, with a moderate/high prevalence.…”

“…The articles were classified according to their origin in three European regions. The main characteristics of these studies are shown in Tables 1-3: Table 1 The oldest article was published by Horvath et al in 1979 [46], and the most recent was published by Abdiyeva et al in 2019 [51]. All articles were cross-sectional studies (descriptive studies).…”

“…Major risk factors, such as occupations associated with animal husbandry (especially of sheep and goats) [6,29,31,45,[47][48][51][52] and agricultural and agropastoral activities [4,6,32,45,50,52] were identified in this study (no matter the geographical zone). Also another major risk https://doi.org/10.1371/journal.pntd.0008094.g002…”

Serological investigation of orthohantaviruses in patients with fever of unknown origin in Kazakhstan

“…Parallel investigations of the same FUO samples used in this study for other arthropod‐borne infectious showed that some serum samples with confirmed orthohantavirus IgG antibodies were reactive also for other agents: for Crimean‐Congo haemorrhagic fever virus (CCHFV), six IgG serum samples, for Rickettsia spotted fever group ELISA (IgG), 13 serum samples and for Rickettsia typhus group ELISA, 15 serum samples. However, none of the patients that were orthohantavirus IgM positive had simultaneously antibodies against CCHFV, Rickettsia of spotted fever group and Rickettsia of typhus group (Abdiyeva et al, ).…”

“…A cross‐sectional descriptive study was set up in 2015–2016 among patients with FUO in Kazakhstan in the Almaty and the Kyzylorda region (Figure ). In these two regions, 13 hospitals were selected to conduct various studies in patients with FUO with a focus on rodent‐ and arthropod‐borne infections (Abdiyeva et al, ).…”