Copro-PCR based detection of bovine schistosome infection in India

Mammalian and Avian Larval Schistosomatids in Bangladesh: Molecular Characterization, Epidemiology, Molluscan Vectors, and Occurrence of Human Cercarial Dermatitis

Schistosomiasis is a neglected tropical disease (NTD) caused by blood flukes (Schistosoma spp.). Schistosomatids affect a wide array of vertebrate hosts, including humans. In the present study, multiple species of schistosomatids were identified by isolating schistosomatid cercariae (SC) from naturally infected snails. We also described different biotic and abiotic factors influencing SC infections in snails and reported human cercarial dermatitis (HCD) for the first time in Bangladesh. A total of 22,012 snails of seven species: Lymnaea auricularia, L. luteola, Indoplanorbis exustus, Physa acuta, Viviparus bengalensis, Brotia spp., and Thiara spp., were collected and examined. Among these snails, 581 (2.6%) belonging to five species: L. luteola, L. auricularia, P. acuta, I. exustus, and V. bengalensis, were infected with SC. The rate of infection was the highest for L. luteola (11.1%), followed by L. auricularia (5.3%), and was the lowest for V. bengalensis (0.4%). Prevalence in snails was the highest in September (16.8%), followed by October (9.5%) and November (8.8%), and was the lowest in colder months, such as January (1.8%) and February (2.1%). Infections with schistosomatids were more common in larger snails and snails collected from sunny areas. We confirmed the presence of Schistosoma indicum, S. incognitum, S. nasale, S. spindale, and Trichobilharzia szidati by PCR and sequencing. Through a questionnaire survey, we detected HCD in 214 (53.5%) individuals, and the infection rate was almost equally distributed across all professions. Collectively, the present results suggest that lymnaeid snails are the main vector for Schistosoma spp. prevalent in Bangladesh, and schistosomatids with zoonotic potential are also prevalent.

A Novel PCR-RFLP to Detect and Differentiate Schistosoma spindale and S. indicum, the Pathogenic Schistosomes in Indian Cattle

PURPOSE

Visceral schistosomosis is an economically important trematode infection caused by Schistosoma spindale and S. indicum in among ruminants. The lack of sensitive diagnostic tools has often led to underestimation of the prevalence in live animals. A sensitive copro-PCR targeting partial mitochondrial gene was developed to detect Schistosoma spp. However, this protocol could not differentiate between the two species. This study was conducted to explore the possibility of species differentiation using restriction fragment length polymorphism of PCR products (PCR- RFLP).

METHODS

Polymerase chain reaction was carried out to amplify mitochondrial gene of adult S. spindale and S. indicum. Copro PCR was done with schistosome-positive faecal samples. A novel PCR-RFLP was designed targeting the Hpy166II recognition sequence in the mitochondrial gene sequence of S. indicum.

RESULT

The PCR using primers targeting the mitochondrial gene of S. spindale and S. indicum amplified a distinct product of approximately 454 bp with adult fluke as well as faecal DNA, which upon RFLP with Hpy166II yielded 330 bp and 124 bp products with S. indicum amplicons alone.

CONCLUSION

The novel PCR-RFLP possesses the potential to be used in epidemiological surveys among bovines and in snail intermediate hosts to screen for S. spindale and S. indicum infection.

Dot blot platform as a novel diagnostic kit: rapid, accurate, and on-site detection of Schistosoma mansoni in urine samples of hard to detect individuals

Rapid diagnostics provide actionable information for patient care at the time and site of an encounter with the health care system. The mainstay of infectious diseases care is early detection (case finding) and treatment completion, but for many, it is hard to identify positive individuals, as is the case of infection with low burden in schistosomiasis, a parasitic disease common in the tropics and subtropics. We developed a new, accurate, and fast Dot blot methodology (iDot) to indirectly detect Schistosoma mansoni in individuals with very low parasite burden using urine samples. Accuracy of 0.74 was obtained with a significant difference between negative and positive patients and a substantial agreement was found when iDot was compared with five available methods. Our analysis also revealed the superiority of iDot in detecting negative individuals from non-endemic sites, thus, presenting the lowest rate of false positives. This new method called iDot is convenient and suitable for qualitative and quantitative detection of schistosomiasis in individuals with low parasite burden.