Seasonal dynamics of Fasciola gigantica transmission in Prafi district, Manokwari Regency, West Papua, Indonesia

Background and aim: Indonesia's farming practices are a perfect setting for establishing an infection with Fasciola gigantica which can result in economically detrimental. The objectives of the current study were to describe and analyze the transmission dynamics of fasciolosis (F. gigantica) in Prafi District, to provide information on effective control strategies and to identify risk factors associated with fasciolosis in cattle.

Materials and methods: Fecal samples were purposively collected from the rectum of 60 beef cattle in Prafi District, Manokwari Regency, West Papua Province, Indonesia. The samples were collected once a month for 8 months from April 2019 to November 2019. Furthermore, the samples were taken from two rearing system groups: 30 stall cattle and 30 cattle in a palm oil garden. The presence of F. gigantica eggs in the fecal samples was examined using a modified Danish Bilharziasis Laboratory technique-sedimentation. Meanwhile, the antigenic diagnosis of Fasciola in the fecal samples was analyzed using an enzyme-linked immunosorbent assay kit to perform an indirect sandwich assay on feces. Snails were collected from an irrigation canal, rice field, and palm oil garden canal around Prafi District. These snails were examined for infection with cercariae larvae of F. gigantica by cercarial shedding and crushing techniques.

Results: The peak occurrence of F. gigantica infection was identified in August (65.00%) and the lowest in June (35.00%). The highest prevalence of fasciolosis in cattle was recorded in August and November (90.00%) and the lowest was in May (40.00%). Moreover, the highest prevalence of fasciolosis in cattle exposed to the palm oil garden was recorded in April (53.33%) and the lowest prevalence of F. gigantica infection was recorded in June (23.33%). In total, 2046 snails were screened by the cercarial shedding and crushing method; of these, 426 (20.82%) were found to be positive for trematode cercariae. The prevalence of F. gigantica infection in Lymnaea spp. snails was highest in November (47.46%) and lowest in April (9.28%).

Conclusion: The current study shows that beef cattle grown in two types of rearing systems in Prafi District were infected with F. gigantica during the dry and rainy season. It was revealed that Lymnaea spp. are common snails found in and around Prafi District, and can act as intermediate hosts with an infective stage of trematode. The transmission to cattle was highly effective, despite the short activity period, the low infection rate of snails, and the incidental anthelminthic treatment.