Prevalence of Schistosoma japonicum infection in water buffaloes in selected areas in Davao del Norte and Davao de Oro, the Philippines

Abstract

Background and Aim: Schistosomiasis (SCH) japonica is a zoonotic disease that can infect several mammalian hosts. Bovines, particularly water buffaloes, are considered the most important reservoir hosts due to the high levels of schistosome eggs, they excrete into the environment. In the Philippines, the previous studies have revealed a high prevalence of SCH in bovines in selected provinces in Luzon, Visayas, and Mindanao. However, there is a lack of studies on SCH in the Davao Region, Mindanao, where the infection remains a public health concern. This study aimed to determine the prevalence of SCH in water buffaloes in four barangays (villages) each in Braulio Dujali, Davao del Norte and Maragusan, Davao de Oro, Southeastern Mindanao, the Philippines. Materials and Methods: Fecal samples from 91 water buffaloes were collected intrarectally, processed using the formalin-ethyl acetate sedimentation technique, and examined microscopically to determine the prevalence of SCH. Results: A total of three water buffaloes (8.6%) in Maragusan were determined to be positive for Schistosoma japonicum, while none in Braulio Dujali. The prevalence of other parasites (Fasciola spp. [53.8%], Paramphistome spp. [20.9%], Amphistome spp. [16.5%], Strongyle spp. [11.0%], Balantidium spp. [9.9%], Eurytrema spp. [2.2%], and Gongylonema pulchrum [1.1%]) was also observed. Conclusion: The results of the study provide baseline data on the presence of S. japonicum in water buffaloes in the Davao Region, Mindanao. Strategies for controlling and eliminating SCH in animal reservoir hosts, especially in water buffaloes, are necessary for the long-term control and elimination of SCH in humans.

The status of schistosomiasis japonica control in the Philippines: The need for an integrated approach to address a multidimensional problem

“…A recent study in South Cotabato showed that 48.6% of cattle and 60.5% of water buffaloes were positive for the infection using FEA-SD technique [42]. Another recent study revealed that 8.6% of sampled water buffaloes in Maragusan, Davao de Oro, were positive for schistosomiasis japonica [43]. As mentioned above, schistosomiasis japonica was also noted in other mammalian reservoir hosts [29][30][31][32].…”

Transmission-Blocking Vaccines against Schistosomiasis Japonica

“…These findings indicate that the prevalence rates of schistosomiasis can vary even in endemic areas, as highlighted in an extensive review by Tenorio et al [84]. It is argued that the low prevalence reported in some studies could also be a result of the poor sensitivity of the tests used for stool analysis and can be improved by adjusting the FEA-SD protocol used and utilizing more sensitive techniques such as the polymerase chain reaction (PCR) tests [72,83]. It is, however, necessary to ascertain the impact of a transmission-blocking vaccine in these regions, as livestock animals, particularly water buffalo, are allowed to graze in contaminated fields.…”

“…It is interesting to note the variation in prevalence rates of schistosomiasis in different host animals in the Philippines. The prevalence rate of S. japonicum in water buffalo in the Philippines was previously reported to be low or even absent, and it was thought that rodents and canines were the main reservoir hosts for schistosomiasis transmission, having higher prevalence rates than water buffalo [31,[80][81][82][83]. In fact, the prevalence rates of schistosomiasis in rodents were reported to be as high as 73%, while dogs had up to 19% [80,81,84].…”

Management and control of schistosomiasis in Agusan del Sur, Philippines: A modeling study

“…Furthermore, prevalence of schistosomiasis in bovines in known endemic areas is as high as 90%. It is now believed that animal reservoir hosts, especially carabaos, are important drivers of transmission in these areas [25][26][27][28][29].…”