Epidemiological Investigation on Genital Myiasis of Bactrian Camels in Parts of Inner Mongolia, China

The incidence and prevalence of Bactrian camel genital myiasis seriously endanger the health of camels and hinder the healthy development of Bactrian camel industry. In order to further understand the epidemic situation of the disease in main production areas of Bactrian camels in Inner Mongolia, China, from May to October 2021, 3 areas with severe incidences in Alxa Left Banner, Urad North Banner and Durbed Banner were selected for epidemiological investigation. Total of 2038 female camels in 21 camel herds were investigated. The results showed that the overall prevalence rate was 26.6%, the highest incidence group reached 82.6%, while the lowest group was only 1.4%. The prevalence rates of Bactrian camel genital myiasis in Alxa Left Banner, Urad North Banner and Durbed Banner was 28.0%, 23.8% and 23.7%, respectively. The pathogen of Bactrian camel genital myiasis is Wohlfahrtia magnifica , and the highest prevalence often occurs in July to August in each year. The prevalence rate in female camels under 5 year-old was lower than that of in adult camels, and it was highest in female camels between 5-15 years old and give birth 2-4 times and no deaths were found. The prevalence rate in free-range female camels was higher than that in half-house-raised camels, and the morbidity was lowest in fully-housed female camels. Camels grazing on pastures near the lakes and riverbanks had higher morbidity than that of in camels grazing on other pastures. Therefore, the morbidity of genital myiasis in Bactrian camels is significantly affected by age, number of deliveries, feeding method, different regions and pasture types.