Determination of Seroprevalence and Risk Factors of Crimean–Congo Haemorrhagic Fever (CCHF) in the Endemic Region in Turkey: A Population-Based Cross-Sectional Study

Abstract

Objectives. Turkey is one of the countries that has the most cases of CCHF in recent years among the endemic countries. The disease also poses an important health threat with high mortality rate. The aim of the study was to determine the seroprevalence and risk factors of CCHF in adults aged ≥20 years in Tokat in the endemic region, Turkey. Methods. In this population-based cross-sectional study, a total of 85 Family Medicine Units (FMUs), from over 170 in Tokat, were randomly selected using 50% sampling. The sample size was determined among the subjects aged ≥20 who registered with the FMUs, due to gender, age group, and the urban/rural population size of Tokat using the stratified cluster sampling method. Subjects were invited to the FMUs. A questionnaire was performed face to face. The blood samples were taken, and anti-CCHFV IgG antibodies were measured with ELISA method. Results. 1272 (54.9%) out of 2319 participants were female, and the mean age was 47.3 ± 15.3. Anti-CCHFV IgG seropositivity was 5.6% (n = 130). Seropositivity rates in terms of adjusted odds ratios (AOR) were higher 2.53 times (95% CI: 1.57–4.08; p = 0.001 ) in males; 4.05 (95% CI: 2.14–7.65; p < 0.001 ) in age group ≥65; 0.33 (95% CI: 0.14–0.76; p < 0.001 ) in graduates of high school and above; 0.71 (95%CI: 0.33–1.52; p < 0.001 ) in ones with good income; 1.84 (95%CI: 1.18–2.86; p < 0.001 ) in farmers; 1.64 (95% CI: 1.04–2.27; p < 0.001 ) in people dealing with animal husbandry; and 1.02 (95% CI: 1.03–2.29; p < 0.001 ) in those with history of tick contact. Conclusions. CCHF seroprevalence is still a common public health problem in Tokat, Turkey. Male gender, advanced age group, low-educated, low-income, farmers, animal husbandry, and history of tick contact were found to be risk factors for CCHF. The importance of this kind of community-based studies to identify the seroprevalence in regional and national level increases even more.

Kırım Kongo Kanamalı Ateşi Virüsünün Tokat/Türkiye’de PCR Tanısı, Epidemiyolojik ve Klinik Verileri

“…A total of 11,041 CCHF cases were reported between 2002 and 2018 in Türkiye, and the case-mortality rate is 4.8% (10). In this study, the rate was 5.95%, which was consistent with Türkiye in general.…”

Seroprevalence of Crimean Congo Hemorrhagic Fever Virus in Occupational Settings: Systematic Review and Meta-Analysis

“…The 33 studies included in the analyses, all of them published from 2007 to 2022, are summarized in Table 1 [ 13 , 14 , 21 , 22 , 23 , 24 , 25 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ]. Among them, 17 (51.51%) were published after 2014, when the WHO first identified CCHF as a global health threat [ 20 ].…”

“…The eventual sample included: 17 estimates based on abattoir workers for 3657 total samples (range 6 to 1995) [ 13 , 14 , 23 , 25 , 38 , 39 , 40 , 41 , 42 , 45 , 46 , 47 , 48 , 50 , 52 , 55 , 59 ], 14 estimates based on farmers for 4558 samples (range 12 to 1034) [ 24 , 25 , 40 , 41 , 43 , 45 , 49 , 51 , 53 , 54 , 55 , 57 , 58 , 62 ], 12 estimates based on animal handlers for 3505 samples (range 32 to 768) [ 40 , 44 , 45 , 47 , 48 , 50 , 51 , 53 , 54 , 55 , 57 , 60 ], 8 estimates based on veterinarians (354 samples, range 1 to 117) [ 25 , 45 , 47 , 50 , 51 , 52 …”

Knowledge, attitudes, and practices regarding Crimean-Congo hemorrhagic fever in a high-prevalence suburban community, southeast of Iran

“…A KAP study conducted in the western neighbor, Turkey, an endemic country with a high prevalence of CCHF, found that 81 % of illiterate people and even 72 % of individuals with elementary education levels had never heard anything about CCHF [ 18 ]. Another study in Turkey on risk factors of CCHF showed that the most seropositivity (Anti-CCHFV IgG) had been detected in low-educated and low-income groups [ 8 ]. These results show the importance of education and economic conditions, especially for people dealing with livestock husbandry.…”

“…Iran and its west and neighboring east countries, Turkey and Pakistan, are considered endemic countries for CCHF. This disease is now reported in 27 of 31 Iranian provinces [ 5 , 8 , 9 ]. A space-time analysis revealed the highest incidence of CCHF in Iran occurred in the eastern regions [ 10 ].…”