Epidemiological analysis and potential factors affecting the 2022-23 Crimean-Congo hemorrhagic fever outbreak in Iraq

Crimean-Congo hemorrhagic fever (CCHF) is an acute tick-borne disease with a case fatality rate of up to 40% in humans, posing a significant health threat. This study investigates the 2022-23 CCHF outbreaks in Iraq, the highest recorded to date, and analyzes potential factors at the human-animal-environmental interface. Data from the Iraqi government, the World Health Organization, and the World Bank were used to analyze CCHF trends and affecting factors. This included epidemiological reports, clinical data, tick infestation and seroprevalence studies, and climate data. Descriptive and statistical analyses examined case trends, geographic and demographic characteristics, clinical manifestations, risk factors, seasonal patterns, and influencing factors. A sudden rise in CCHF cases began in southern Iraq in April 2022 and expanded across all governorates, with a shift toward urban areas. Higher incidence was observed among males, aged 25-44, and those involved in slaughtering. The most common clinical manifestation was fever (97%), followed by hemorrhagic symptoms (54%). Bleeding from the gums or mouth and subcutaneous bleeding were more frequent in patients with fatal outcomes. Seasonal patterns showed peaks during spring and fall, correlating with tick activity and potentially exacerbated by climate change. Tick infestation and seroprevalence studies indicated a high prevalence of Hyalomma ticks and CCHF seropositivity among domestic animals in southern Iraq (60%), consistent with the distribution of CCHF human cases. Iraq's ongoing CCHF outbreak demands multidisciplinary One Health strategies. The Iraqi government has adopted such a control strategy, contributing to regional and global efforts to enhance pandemic preparedness.