MAPPING THE EPIDEMIOLOGY OF CRIMEAN-CONGO HEMORRHAGIC FEVER ACROSS THE DURAND LINE (PAKISTAN & AFGHANISTAN INTERNATIONAL BORDER)

Abstract

Background: Owing to the zoonotic infectious nature of Crimean-Congo Hemorrhagic Fever (CCHF), increased outbreaks in the recent years, endemic in the area and limitations of the previous data, this study aims to update the spatial prevalence and to determine the risk factors associated with CCHF on both sides of the Durand line between Balochistan (Pakistan) and Afghanistan.

Method: A retrospective study was conducted to identify the CCHF cases occurred in Balochistan and in Afghanistan from 2012 to 2014. Chi-square and Pearson’s correlation coefficient (r) statistic was used to determine the association between the variables and CCHF cases. The spatial distribution of CCHF cases was analyzed by the Geographic Information System (ArcGIS 10.2).

Results: There were 85 (out of 124) CCHF positive cases (75 cases from Balochistan and 10 cases from Afghanistan) confirmed with polymerase chain reaction (PCR) or enzyme-linked immunosorbent assay (ELISA). Dominantly, middle aged (18-40 years) individuals of rural areas particularly men (70 cases) were more affected by CCHF. The individuals who had contact with the animals [OR=9.05 (CI=3.79-21.61)], with history of tick bites (22 cases) [OR=4.19 (CI=1.17-14.98)] were higher at risk of attaining CCHF infection than the others. All the cases were reported in a dry climate (low rainfall of 0-18 mm) between the altitude of 1968-2623 meters above the sea level with a positive correlation (r = 0.85) to monthly average temperature while maximum appearing 

in the peak summer months (May to August). The case fatality rate among the CCHF positive cases in Balochistan (Pakistan) was lower (17%) than in Afghanistan (30%). The cumulative yearly incidence of CCHF in 2013 and 2014, in Balochistan (Pakistan) was 0.36% and 0.32% respectively, while in Afghanistan it was 0.072% and 0.168%, respectively.

Conclusion: The uncontrolled movements of people across the border, lack of awareness, cultural tendencies, and conventional agricultural and animal handling practices are important factors for the circulation of CCHFV in Balochistan and Afghanistan. An effective awareness program with active surveillance system with vector control efforts are urgently needed to avoid the damage.