Seroepidemiology and molecular characterization of Grimean-Congo hemorrhagic fever in Punjab province Pakistan

Abstract

SERO-EPIDEMIOLOGICAL SURVEY OF CRIMEAN-CONGO HEMORRHAGIC FEVER AMONG HUMAN POPULATION OF PUNJAB PROVINCE PAKISTAN Clinical as well as mild or sub-clinical form of Crimean-Congo Hemorrhagic Fever (CCHF) is reported across many parts of the world. However, in a resource-limited setting such as Pakistan, disease remain under-reported simply because the disease diagnostic and subsequent interventions are exclusively directed to manage clinical form of infection. With this background, coupled with risk factor analysis, we performed a serological survey of human population (n = 1,052) originating from select districts of Punjab province with (endemic area, n = 721) and without (non-endemic area, 309) a history of CCHF. Blood samples and questionnaire-based data was collected from each of the patient with a history of fever (>100.4° F) and screened for anti-CCHF IgG by Enzyme Linked Immunosorbent Assay. Univariate and multivariate analysis was conducted on the obtained data. With an overall seroprevalence of 2.09% (n = 22, 95% CI: 1.38 – 3.14), a more number of patient were seropositive from areas having history of CCHF (n = 20, 2.77%, 95% CI: 1.58 – 3.97) than areas having no history of CCHF (n = 2, 0.64%, 95% CI: 0.25 – 1.54). The seroprevalence was significantly associated with patients having a history of animal contact (the farmers) (OR= 2.729, 95% CI: 1.10 – 6.75, p = 0.02) and those living in rural setting (OR=6.04, 95% CI: 1.40- 26.01, p = 0.01). Including at-risk and general population originating from both endemic and non-endemic areas, the study outcome ascertains a continued well-integrated disease surveillance in future to better comprehend disease control interventions. Key Words: Punjab, CCHF, Seroprevalence, Human population, Risk factors SEROPREVALENCE OF CRIMEAN-CONGO HEMORRHAGIC FEVER AMONG THREE SELECTED RISK HUMAN GROUPS IN PAKISTAN Though the incidence of Crimean-Congo hemorrhagic fever (CCHF) in human is linked with the presence of animal in close vicinity, there is a paucity of data on rate of seroconversion in human linked with livestock. Therefore, the objective of present study is to find out the high-risk group associated with livestock animals in the area of Pakistan having history of CCHF. For this purpose, coupled with risk factor analysis, we performed a serological survey of three select risk groups i.e abattoir workers (n = 137), milkmen (n = 169) and animal handlers (n = 147). Blood samples and questionnaire-based data was collected from each of the participant and screened for anti-CCHF IgG by Enzyme Linked Immunosorbent Assay. Then seroprevalence and risk factors were examined in all select risk groups. Highest seroprevalence was observed in animal handlers (9.52%, n = 14, 95% CI: 4.68 - 13.99) followed by abattoir workers (6.57%, n = 9, 95% CI: 2.42 - 10.72) and milkmen (1.78%, n = 3, 95% CI: 0.24 - 4.24). The odds of seroconversion were significantly associated with abattoir workers (OR: 6.9, 95% CI: 1.37 to 34.75, p = 0.01) and animal handlers (OR: 4.72, 95% CI: 1.40 to 15.91, p = 0.009) having more than 40 years of age than that of younger ones (<40 years). The risk of seropositivity was more in illiterate abattoir workers (OR: 4.29, 95% CI: 0.86 to 21.40, p = 0.08), milkmen (OR: 6.36, 95% CI: 0.32 to 125.1, p = 0.2) and animal handlers (OR: 3.04, 95% CI: 0.80 to 11.30, p = 0.15) than literate participants. The present study concluded the seroprevalence of CCHF in high risk groups of an endemic area of Pakistan and the study outcome ascertains a well-integrated disease surveillance in future to better comprehend disease control interventions. Key Words: CCHF, Chakwal, risk groups, seroprevalence, risk factors