Prevalence of Anaplasmosis and Its Associated Risk Factors in Camels at Lakki Marwat, Khyber Pakhtunkhwa, Pakistan

Background: Anaplasmosis is a tick-borne rickettsial disease affecting a wide range of domestic animals, including camels. In camels, infections are often subclinical or occur as co-infections, but clinical cases can present with fever, anemia, weight loss, ataxia, anorexia, jaundice, and lymph node enlargement. This study provides the first investigation of camel anaplasmosis in Lakki Marwat, aiming to determine its prevalence and associated risk factors in this region. Methods: A cross-sectional survey of 384 one-humped camels (Camelus dromedarius) was conducted from July 2024 to June 2025. Blood samples were collected and examined by Giemsa-stained thin blood smear microscopy for Anaplasma parasites. Packed cell volume (PCV) was measured to assess anemia, and a competitive ELISA was used on sera to detect Anaplasma antibodies. Data on host factors (age, sex, breed, body condition), husbandry, and tick infestation were recorded. Associations between potential risk factors and infection status were analyzed using chi-square tests for categorical variables and t-tests for continuous variables. Results: Microscopic examination revealed an overall Anaplasma infection prevalence of 13.5% (52/384). Anaplasma marginale was the most common species detected, followed by A. centrale, including a few co-infections. Tick-infested camels had a significantly higher infection rate (25.0%) than tick-free camels (5.4%) (p < 0.001). Camels in poor body condition showed higher infection prevalence (30.0%) than those in good condition (8.3%) (p < 0.001). No significant differences in infection were observed by age, sex, breed, or village origin (p > 0.05). Infected camels had lower mean PCV (≈22%) compared to uninfected (≈29%) (p < 0.001), indicating anemia. Serologically, 19.0% of camels had anti-Anaplasma antibodies, confirming additional subclinical exposures. Conclusion: Camel anaplasmosis is present in the study region with an overall infection prevalence of about 13%, and tick infestation and poor body condition are key risk factors. The disease largely occurs subclinically, associated with anemia in infected animals. These findings underscore the need for improved tick control and preventive strategies to mitigate anaplasmosis in camels. Future studies should incorporate molecular diagnostics to identify Anaplasma species and further explore epidemiological dynamics in Pakistan’s camel populations.