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Susceptibility of snail vectors to Oriental anthropophilic Schistosoma

Yuan HC, Upatham ES, Kruatrachue M, Khunborivan V

Southeast Asian J. Trop. Med. Public Health, 1984 Mar;15(1):86-94.
PMID: 6740384

Laboratory experiments were carried out to study the susceptibility of snail vectors to Oriental anthropophilic Schistosoma. Oncomelania hupensis hupensis was readily infected with the local strain of Schistosoma japonicum (Chinese strain), and also infected with S. japonicum (Philippines strain). O.h. quadrasi was only susceptible to its S. japonicum (Philippines strain). The Oncomelania races were refractory to S. mekongi, S. japonicum-like species (Malaysian strain). Tricula aperta (beta race) was readily infected with S. mekongi, S. sinensium and S. japonicum-like species from Malaysia, but not S. japonicum. T. bollingi was susceptible to S. sinensium and S. mekongi. Robertsiella kaporensis was only susceptible to the local strain, S. japonicum-like species from Malaysia. Geographical isolation may be the cause of these differences in compatibility between the snail vectors and the schistosome parasites.

Matched MeSH terms: Schistosomiasis/parasitology*
Fulltext Autochthonous human schistosomiasis, Malaysia

Latif B, Heo CC, Razuin R, Shamalaa DV, Tappe D

Emerg Infect Dis, 2013 Aug;19(8):1340-1.
PMID: 23876448 DOI: 10.3201/eid1908.121710
Matched MeSH terms: Schistosomiasis/parasitology
Detection of Schistosoma spindale ova and associated risk factors among Malaysian cattle through coprological survey

Tan TK, Low VL, Lee SC, Panchadcharam C, Tay ST, Ngui R, et al.

Jpn. J. Vet. Res., 2015 May;63(2):63-71.
PMID: 26164875

The present study was conducted to determine the occurrence of Schistosoma spindale ova and its associated risk factors in Malaysian cattle through a coprological survey. A total of 266 rectal fecal samples were collected from six farms in Peninsular Malaysia. The overall infection rate of S. spindale was 6% (16 of 266). Schistosoma spindale infection was observed in two farms, with a prevalence of 5.4% and 51.9%, respectively. This trematode was more likely to co-occur with other gastro-intestinal parasites (i.e., Dicrocoelium spp., Paramphistomum spp., strongyle, Eimeria spp. and Entamoeba spp.). Chi-square analysis revealed that female cattle are less likely to get S. spindale infection as compared to male cattle (OR = 0.3; 95% CI = 0.08-1.06; p < 0.05), and cattle weighing lower than 200 kg, were significantly at higher risk than those higher than 200 kg (OR = 5; 95% CI = 1.07-24.79; p < 0.05) to the infection. Multivariate analysis confirmed that among the cattle in Malaysia, the age (cattle with two year old and higher: OR = 21; 95% CI = 2.48-179.44; p < 0.05) and weight (weighing 200 kg and lower: OR = 17; 95% CI = 3.38-87.19; p < 0.05) were risk factors for S. spindale infection among Malaysian cattle.

Matched MeSH terms: Schistosomiasis/parasitology
Fulltext Upper genital schistosomiasis mimicking an ovarian tumour

Shekhar KC, Soh EBS, Jayalakshmi P

Med J Malaysia, 2000 Sep;55(3):371-5.
PMID: 11200720

Schistosomiasis is a widely prevalent disease in the world and usually involves the gastro-intestinal and urinary tract. The involvement of the female genital tract has been well-established in S. haematobium infections and is rare with S. japonicum infections. This case involves a Filipino female who was admitted to the University Hospital Kuala Lumpur for right iliac fossa pain and was diagnosed initially as acute appendicitis. Ultrasound showed a multi-septated pelvic cyst leading to a provisional diagnosis of ovarian torsion. Intraoperatively a right parovarian cyst was detected and removed. Histology revealed a congested cyst wall with areas of haemorrhage with several viable and calcified eggs of S. japonicum measuring 85 microns x 62 microns. Within the cystic cavity blood admixed with eggs were seen. Confirmation was carried out by using the indirect haemagglutination (IHA) test. This is a first report of upper genital schistosomiasis mimicking an ovarian tumour.

Matched MeSH terms: Schistosomiasis/parasitology
Schistosoma japonicum-like ova in liver and rectal biopsies of three cases in Sabah, Malaysia

Kan SK, Kay RW, Thomas I

Southeast Asian J. Trop. Med. Public Health, 1979 Mar;10(1):97-9.
PMID: 573502

Three cases of schistosomiasis in 2 Filipinos and one Chinese in Sabah are reported. Diagnosis was based on incidental histological findings of Schistosoma japonicum-like ova in the liver and rectal biopsies. As these 3 patients are immigrants to Sabah, it is assumed that they are imported cases, and that Sabah has been free of the disease from 1970 to 1977.

Matched MeSH terms: Schistosomiasis/parasitology
Fulltext Detection of Schistosoma mansoni and Schistosoma haematobium by Real-Time PCR with High Resolution Melting Analysis

Sady H, Al-Mekhlafi HM, Ngui R, Atroosh WM, Al-Delaimy AK, Nasr NA, et al.

Int J Mol Sci, 2015;16(7):16085-103.
PMID: 26193254 DOI: 10.3390/ijms160716085

The present study describes a real-time PCR approach with high resolution melting-curve (HRM) assay developed for the detection and differentiation of Schistosoma mansoni and S. haematobium in fecal and urine samples collected from rural Yemen. The samples were screened by microscopy and PCR for the Schistosoma species infection. A pair of degenerate primers were designed targeting partial regions in the cytochrome oxidase subunit I (cox1) gene of S. mansoni and S. haematobium using real-time PCR-HRM assay. The overall prevalence of schistosomiasis was 31.8%; 23.8% of the participants were infected with S. haematobium and 9.3% were infected with S. mansoni. With regards to the intensity of infections, 22.1% and 77.9% of S. haematobium infections were of heavy and light intensities, respectively. Likewise, 8.1%, 40.5% and 51.4% of S. mansoni infections were of heavy, moderate and light intensities, respectively. The melting points were distinctive for S. mansoni and S. haematobium, categorized by peaks of 76.49 ± 0.25 °C and 75.43 ± 0.26 °C, respectively. HRM analysis showed high detection capability through the amplification of Schistosoma DNA with as low as 0.0001 ng/µL. Significant negative correlations were reported between the real-time PCR-HRM cycle threshold (Ct) values and microscopic egg counts for both S. mansoni in stool and S. haematobium in urine (p < 0.01). In conclusion, this closed-tube HRM protocol provides a potentially powerful screening molecular tool for the detection of S. mansoni and S. haematobium. It is a simple, rapid, accurate, and cost-effective method. Hence, this method is a good alternative approach to probe-based PCR assays.

Matched MeSH terms: Schistosomiasis/parasitology
Induction of intestinal lesions in rabbits with Koyan and Baling strains of Schistosoma malayensis Sp N

Shekhar KC, Pathmanathan R

Southeast Asian J. Trop. Med. Public Health, 1992 Mar;23(1):92-7.
PMID: 1523486

Schistosoma malayensis Sp N is a putative new species of schistosome discovered in Peninsular Malaysia in 1973. This paper comprises the first report on the detailed gastrointestinal pathology present in rabbits infected with strains of the parasite. Two different strains of schistosome--the Baling and Koyan strains--from two different ecosystems were used to infect inbred rabbits and the resulting pathophysiology was studied. Our results showed that the Baling strain of S. malayensis was more virulent than the Koyan strain and produced nodular, segmental circumferential lesions and large bilharziomas measuring 1-7 cm in diameter in the distal jejunum, ileum and the ileo-caecal junction. The findings indicate that the Baling strain of S. malayensis was more pathogenic for rabbits as compared with the Koyan strain--in relation to the gross pathology of the gut and the tissue egg load. Earlier reports have shown that rabbits infected with S. japonicum induces significant intestinal lesions in rabbits (Cheever et al, 1980 a,b) but these animals are refractory to infection with S. mekongi (Byram and Lichtenberg, 1980). Our studies show that the two strains of S. malayensis adapted well in rabbits. It is also established that in rabbits, the virulence of the Baling strain of S. malayensis is greater than that of S. mekongi and approximates that of S. japonicum.

Matched MeSH terms: Schistosomiasis/parasitology
Serological evidence of schistosomiasis among Orang Asli from three areas of Peninsular Malaysia

Greer GJ, Anuar H

Southeast Asian J. Trop. Med. Public Health, 1984 Sep;15(3):303-12.
PMID: 6523170

Using ELISA and COPT diagnostic tests, serological evidence of Malaysian schistosomiasis was discovered among Orang Asli populations from three areas in Peninsular Malaysia. Serum samples collected in 1975 indicated an ELISA-positive prevalence of 25% and a COPT prevalence of 11% from Pos Iskandar, Pahang and an ELISA prevalence of 13% and a COPT of 4% from Bukit Lanjan, Selangor. Resurveys at these site in 1982-1984 showed a continued presence of serological positive individuals but prevalence rates were markedly lower: 7% and 1% for ELISA and 4% and 2% for COPT at Pos Iskandar and Bukit Lanjan respectively. Snail hosts were not found at either site. The source of infection for persons living in these lowland areas remains unknown. In a third area, Kuala Tahan, Pahang, located in the foothills of the central mountain range, foci of transmission have been found near to Orang Asli settlements. The serological prevalence rate among Negrito Orang Asli in that study area was 9% for ELISA and 4% for COPT. Thirty-three of 36 COPT-positive sera produced vacuolated bleb precipates and in 31 these were the only reactions seen. The high percentage of positives producing only these precipates suggests that among Orang Asli schistosomiasis patients such reactions are not an indication of recently acquired infection as has been reported for schistosomiasis patients in the Philippines.

Matched MeSH terms: Schistosomiasis/parasitology
Fulltext Prevalence and associated factors of Schistosomiasis among children in Yemen: implications for an effective control programme

Sady H, Al-Mekhlafi HM, Mahdy MA, Lim YA, Mahmud R, Surin J

PLoS Negl Trop Dis, 2013;7(8):e2377.
PMID: 23991235 DOI: 10.1371/journal.pntd.0002377

BACKGROUND: Schistosomiasis, one of the most prevalent neglected tropical diseases, is a life-threatening public health problem in Yemen especially in rural communities. This cross-sectional study aims to determine the prevalence and associated risk factors of schistosomiasis among children in rural Yemen.
METHODS/FINDINGS: Urine and faecal samples were collected from 400 children. Urine samples were examined using filtration technique for the presence of Schistosoma haematobium eggs while faecal samples were examined using formalin-ether concentration and Kato Katz techniques for the presence of S. mansoni. Demographic, socioeconomic and environmental information were collected via a validated questionnaire. Overall, 31.8% of the participants were found to be positive for schistosomiasis; 23.8% were infected with S. haematobium and 9.3% were infected with S. mansoni. Moreover, 39.5% of the participants were anaemic whereas 9.5% had hepatosplenomegaly. The prevalence of schistosomiasis was significantly higher among children aged >10 years compared to those aged ≤ 10 years (P<0.05). Multivariate analysis confirmed that presence of other infected family member (P<0.001), low household monthly income (P = 0.003), using unsafe sources for drinking water (P = 0.003), living nearby stream/spring (P = 0.006) and living nearby pool/pond (P = 0.002) were the key factors significantly associated with schistosomiasis among these children.
CONCLUSIONS/SIGNIFICANCE: This study reveals that schistosomiasis is still highly prevalent in Yemen. These findings support an urgent need to start an integrated, targeted and effective schistosomiasis control programme with a mission to move towards the elimination phase. Besides periodic drug distribution, health education and community mobilisation, provision of clean and safe drinking water, introduction of proper sanitation are imperative among these communities in order to curtail the transmission and morbidity caused by schistosomiasis. Screening and treating other infected family members should also be adopted by the public health authorities in combating this infection in these communities.

Matched MeSH terms: Schistosomiasis/parasitology
Schistosomiasis malayensis-like infection among the Penan and other interior tribes (Orang Ulu) in upper Rejang River Basin Sarawak Malaysia

Sagin DD, Ismail G, Fui JN, Jok JJ

Southeast Asian J. Trop. Med. Public Health, 2001 Mar;32(1):27-32.
PMID: 11485090

A serosurvey of various indigenous interior tribes (Orang Ulu) in upper Rejang River Basin Sarawak Malaysia, the site of a multibillion Ringgit hydroelectric power project, found 6.8% of the individual surveyed were seropositive for schistosomiasis, as determined by ELISA method using the soluble egg antigen of Schistosoma malayensis Baling strain. In all age group, the seroprevalence rate is higher (9.5%) in males than in females (4.5%) except for the 31-40 age group. Seroprevalence of schistosomiasis was found to increase with age with the above 60 age group having the highest rate followed by the 31-40 age group. Seroprevalence rate among the tribes ranges from 4.1% among the Penan to 11.6% among the Kajang. There was no seroevidence of schistosomiasis among the Ukits. A snail survey found four snail species including Brotia species, the intermediate host of the lung fluke Paragonimus westermani, however no schistosome snail host was identified. Although schistosomiasis malayensis-like infection may be endemic in the area, its public health significance remains undetermined.

Matched MeSH terms: Schistosomiasis/parasitology
Mitochondrial gene content, arrangement and composition compared in African and Asian schistosomes

Le TH, Humair PF, Blair D, Agatsuma T, Littlewood DT, McManus DP

Mol Biochem Parasitol, 2001 Sep 28;117(1):61-71.
PMID: 11551632

Complete sequences were obtained for the coding portions of the mitochondrial (mt) genomes of Schistosoma mansoni (NMRI strain, Puerto Rico; 14 415 bp), S. japonicum (Anhui strain, China; 14 085 bp) and S. mekongi (Khong Island, Laos; 14 072 bp). Each comprises 36 genes: 12 protein-encoding genes (cox1-3, nad1-6, nad4L, atp6 and cob); two ribosomal RNAs, rrnL (large subunit rRNA or 16S) and rrnS (small subunit rRNA or 12S); as well as 22 transfer RNA (tRNA) genes. The atp8 gene is absent. A large segment (9.6 kb) of the coding region (comprising 14 tRNAs, eight complete and two incomplete protein-encoding genes) for S. malayensis (Baling, Malaysian Peninsula) was also obtained. Each genome also possesses a long non-coding region that is divided into two parts (a small and a large non-coding region, the latter not fully sequenced in any species) by one or more tRNAs. The protein-encoding genes are similar in size, composition and codon usage in all species except for cox1 in S. mansoni (609 aa) and cox2 in S. mekongi (219 aa), both of which are longer than homologues in other species. An unexpected finding in all the Schistosoma species was the presence of a leucine zipper motif in the nad4L gene. The gene order in S. mansoni is strikingly different from that seen in the S. japonicum group and other flatworms. There is a high level of identity (87-94% at both the nucleotide and amino acid levels) for all protein-encoding genes of S. mekongi and S. malayensis. The identity between genes of these two species and those of S. japonicum is less (56-83% for amino acids and 73-79% for nucleotides). The identity between the genes of S. mansoni and the Asian schistosomes is far less (33-66% for amino acids and 54-68% for nucleotides), an observation consistent with the known phylogenetic distance between S. mansoni and the other species.

Matched MeSH terms: Schistosomiasis/parasitology