Infection rate of Schistosoma japonicum in the snail Oncomelania hupensis quadrasi in endemic villages in the Philippines: Need for snail surveillance technique.

Schistosomiasis japonica is one of seven NTDs endemic in the Philippines that continues to threaten public health in the country. The causative agent, the blood fluke Schistosoma japonicum, uses an amphibious snail Oncomelania hupensis quadrasi which can harbor larval stages that multiply asexually, eventually producing the infective cercariae which are shed into the water. Contamination of freshwater bodies inhabited by the snail intermediate host occurs through release of human and animal feces containing S. japonicum eggs. Miracidia hatching from these eggs subsequently infect the snails that inhabit these water bodies. The degree of fecal contamination can vary across snail sites and influences snail infection rates in these sites. In this study, conventional malacological surveys using intensive manual search for snails were conducted from 2015 to 2016 in seven selected endemic provinces, namely Leyte and Bohol in the Visayas and Surigao del Norte, Agusan del Sur, Bukidnon, Lanao del Norte and Compostela Valley in Mindanao. A total of 6,279 O. hupensis quadrasi snails were collected from 38 snail sites. The municipality of Trento in Agusan del Sur recorded the highest number of snail sites (7) that yielded O. hupensis quadrasi snails while only one snail site was found positive for O. hupensis quadrasi snails in Kapatagan in Lanao del Norte and Talibon in Bohol. Alegria in Surigao del Norte yielded the highest number of snail sites (5) that were found to harbor snails positive for S. japonicum infection. The snail infection rates in this municipality ranged from 0.43% to 14.71%. None of the snails collected from Talibon in Bohol was infected. Bohol is the only province among the 28 schistosomiasis-endemic provinces which has reached near elimination status. Snail infection rates were found to vary considerably across snail sites, which could be due to the degree of fecal contamination of the snail sites and their connectivity to water that can serve as contamination source.

Infection rate of Schistosoma japonicum in the snail Oncomelania hupensis quadrasi in endemic villages in the Philippines: Need for snail surveillance technique

@#Schistosomiasis japonica is one of seven NTDs endemic in the Philippines that continues to threaten public health in the country. The causative agent, the blood fluke Schistosoma japonicum, uses an amphibious snail Oncomelania hupensis quadrasi which can harbor larval stages that multiply asexually, eventually producing the infective cercariae which are shed into the water. Contamination of freshwater bodies inhabited by the snail intermediate host occurs through release of human and animal feces containing S. japonicum eggs. Miracidia hatching from these eggs subsequently infect the snails that inhabit these water bodies. The degree of fecal contamination can vary across snail sites and influences snail infection rates in these sites. In this study, conventional malacological surveys using intensive manual search for snails were conducted from 2015 to 2016 in seven selected endemic provinces, namely Leyte and Bohol in the Visayas and Surigao del Norte, Agusan del Sur, Bukidnon, Lanao del Norte and Compostela Valley in Mindanao. A total of 6,279 O. hupensis quadrasi snails were collected from 38 snail sites. The municipality of Trento in Agusan del Sur recorded the highest number of snail sites (7) that yielded O. hupensis quadrasi snails while only one snail site was found positive for O. hupensis quadrasi snails in Kapatagan in Lanao del Norte and Talibon in Bohol. Alegria in Surigao del Norte yielded the highest number of snail sites (5) that were found to harbor snails positive for S. japonicum infection. The snail infection rates in this municipality ranged from 0.43% to 14.71%. None of the snails collected from Talibon in Bohol was infected. Bohol is the only province among the 28 schistosomiasis-endemic provinces which has reached near elimination status. Snail infection rates were found to vary considerably across snail sites, which could be due to the degree of fecal contamination of the snail sites and their connectivity to water that can serve as contamination source.

Discovery of Liopiophila varipes and Protopiophila contecta (Diptera: Piophilidae) from human cadavers.

Here, we present two cases in which larvae of the family Piophilidae were detected in human cadavers. Both cases were found in Tochigi Prefecture, which is located in the middle of Honshu Island, Japan. Case 1: A corpse was found hanging in the sun lounge of a house. Dipteran larvae were collected from inside the spinal canal, despite no visible breach on the skin. The adults derived from these larvae were identified as Piophila casei (Linnaeus, 1758) and Liopiophila varipes (Meigen, 1830). Case 2: Skeletal human remains were found in a mountainous forest. Dipteran larvae were detected in the bone marrow cavity of a tibial section during autopsy. One adult fly derived from the larvae was identified as Protopiophila contecta (Walker, 1860). This is the first report of the identification of L. varipes and P. contecta in human cadavers.

Differential expression and the anti-apoptotic effect of human placental neurotrophins and their receptors.

Neurotrophin (NT) is important in the survival, maintenance and differentiation of neuronal tissue, and functions in follicle maturation, tumor growth, angiogenesis and immunomodulation; however, the expression of NT and its receptors (NTR) in human placenta and their influence on fetal growth are unclear. Here we investigated the correlation of NT and NTR in human placenta with uterine environment and fetal growth. TrkB, a NTR, mRNA was expressed on decidual and villous tissue and increased with gestational age, localizing in the trophoblast layer and endothelium by immunohistochemistry. Villous TrkB mRNA was significantly increased in preeclampsia (PE) than in controls and was higher in the normotensive small for gestational age (SGA) placenta, although it was not significant. It was also significantly increased in the small twin of discordant twin pregnancies. Brain-derived neurotrophic factor (BDNF), the main ligand of TrkB, was expressed in membranous chorion and villous tissue and was significantly higher in maternal plasma in normotensive SGA and PE than in controls. TrkB mRNA expression was up-regulated on cultured villous tissue explants and on JEG-3, a choriocarcinoma cell line, by H(2)O(2) treatment. BDNF decreased apoptotic cells in H(2)O(2)-treated JEG-3, indicating that BDNF/TrkB signaling had anti-apoptotic effects against oxidative stress in JEG-3, suggesting a protective role of BDNF/TrkB in human villous tissue under unfavorable conditions in utero.

Characteristics of granuloma formation and liver fibrosis in murine schistosomiasis mekongi: a morphological comparison between Schistosoma mekongi and S. japonicum infection.

A histopathological study was performed to clarify the characteristics of granuloma formation and liver fibrosis in Schistosoma mekongi infection in comparison with S. japonicum infection. Mice were exposed to S. mekongi (Laotian strain) and S. japonicum (Japanese strain) cercariae, and were dissected at 6, 8, 12, 16, and 20 weeks post-exposure. In the liver, granulomas in S. mekongi infection were cellular, initially organized with foam cells, and continuously appeared in the intralobular area, while granulomas in S. japonicum infection were fibrous and did not continuously appear in the intralobular area. Portal fibrosis was not seen in S. mekongi infection, but was commonly seen in S. japonicum infection in the later weeks. Granulomas in the small intestine were seen mainly in the submucosa with foam cells in S. mekongi infection and without foam cells in S. japonicum infection. The lung granulomas contained mainly histiocytes in both S. mekongi and S. japonicum infection. The absence of portal fibrosis in S. mekongi infection allows schistosome eggs to infiltrate into the intralobular area continuously, which can be what lies behind the ultrasonographic differences; the echogenic network pattern as was seen in S. japonicum infection, has not been noted in S. mekongi infection.

Establishment of a GIS monitoring system for schistosomiasis japonica in Kofu, Japan.

Although the incidence of human infection with Schistosoma japonicum in Japan fell to zero in 1977, the threat of the possible re-emergence of the disease caused by this trematode still exists. Surveillance of the parasite's intermediate host, Oncomelania nosophora, in Kofu basin therefore began in 1996. A simple, new method for monitoring O. nosophora in an at-risk area in Kofu, which is based on a geographical information system (GIS), was established. At each monitoring site (of which there were 120 from 1996 until 2000, and 60 from 2001 until 2003), the O. nosophora in two quadrats, each measuring 25 x 25 cm, were collected. During the study, the exact location of each site was determined using a hand-held global-positioning system (GPS). This allowed all the sites to be digitally mapped, so that anyone with a hand-held GPS could and can reach each site. The snail and location data were processed using commercial GPS/GIS software packages and used to create a risk map for schistosomiasis re-emergence. Although all snails collected between 1996 and 2003 were uninfected, the proportion of investigated sites in which O. nosophora was detected increased from 36.7% in 1996 to 56.7% in 2003. The mean number of O. nosophora collected per snail-positive site fluctuated widely, between 8.2 and 57.4, in each calendar year. Over the study period there appeared to be a shift southwards in the areas with high densities of O. nosophora. The present results indicate that it is possible to utilize a GIS-based method for the long-term monitoring of the possible re-emergence of schistosomiasis japonica in Japan.

Comparative studies on susceptibilities of two different Japanese isolates of Oncomelania nosophora to three strains of Schistosoma japonicum originating from Japan, China, and the Philippines.

Oncomelania nosophora (Gastropoda: Pomatiopsidae) is the intermediate host of Schistosoma japonicum in Japan. Although most of the snails were eliminated during the 20th century, they are still found in two areas in Japan. One area is in the Kofu Basin, including Nirasaki City, in Yamanashi Prefecture. The other is the Obitsu River Basin in Kisarazu City, Chiba Prefecture. Snails collected in Nirasaki and Kisarazu were exposed to 3 geographical strains of S. japonicum originating from Japan, China, and the Philippines. Both isolates of O. nosophora showed high susceptibility to the Japanese strain of S. japonicum (74.0% - 82.2%, for the Nirasaki isolate and 58.0% - 56.0% for the Kisarazu isolate) and low susceptibility to the Chinese strain (0.0% - 1.3% and 1.4% - 7.9% respectively). In contrast, the susceptibility of the snails to the Philippine strain was significantly different (P < 0.01) between the isolates (3.3% - 6.6% for the Nirasaki isolate and 31.9% - 75.9% for the Kisarazu isolate). To examine the differences in infectivity in detail, we conducted histological observations of snails exposed to the Philippine strain at 3 h, 1, 3, and 15 days after miracidial exposure. We found differences in the development of the parasite between the isolates of snails from early after exposure.

Suspected intestinal myiasis due to Dryomyza formosa in a Japanese schizophrenic patient with symptoms of delusional parasitosis.

A third-stage larva of Dryomyza formosa (Wiedemann) (Diptera: Dryomyzidae) was found in the fresh stool of a 27-year-old Japanese woman resident of Shiobara, 150 km north of Tokyo, on 16 November 1998. This is the first record of myiasis due to Dryomyza. Detection of this maggot (2cm long) by the patient herself was associated with her longstanding delusion of abdominal parasitosis as a symptom of chronic schizophrenia. Circumstantial evidence agreed with this being a genuine case of intestinal myiasis, apparently due to accidental ingestion of the insect, with no signs that the patient had contrived the report, nor that the maggot had invaded the stool post-defaecation. This case draws attention to the likelihood that some personality states are predisposed to noticing and reporting myiasis, when it occurs. We review other conditions (mental and physical) that are more prone to myiasis.

Human antibody isotype responses to Schistosoma japonicum egg antigen.

Schistosoma japonicum-infected subjects from Hubei province of China were investigated to determine the class and subclass of the antibody response to soluble egg antigen (SEA), using an enzyme-linked immunosorbent assay. The subjects were 50 acute and 55 chronic cases. In acute cases, the mean OD values for IgA, IgE and IgG3 were very high, while the positive ratios of IgA and IgE were only 78% and 74%, respectively. The positive ratios of IgG, IgM, IgG1, IgG3 and IgG4 were all above 90%. In chronic cases, the mean OD values for IgG, IgG3 and IgG4 were very high, and the positivity rates of IgG, IgG1, IgG3 and IgG4 were all above 90%. Comparing the two study groups, the mean OD values of IgM, IgA, IgE were higher in acute cases than those of chronic cases (p < 0.0001), while the mean OD values of IgG, IgG4 were higher in chronic cases than in acute cases (p < 0.05). The mean OD values of IgG3 in both groups were high and those of IgG2 in both groups were low.

Factors influencing development of free-living generations of Strongyloides stercoralis.

The effects of duration of infection and of temperature and nourishment in cultures on development of free-living generations of Strongyloides stercoralis were studied quantitatively. Rhabditiform larvae, 228-353 microns long, were collected from infected dogs with or without prednisolone treatment using the Baermann apparatus. Cultures were carried out by the filter paper test-tube method under the following condition: incubation temperature 15-40 degrees C and faecal dilution 1:0-1:16. Rhabditiform larvae developed predominantly to free-living females at incubation temperatures of 15-30 degrees C and low faecal dilutions, but filariform larvae appeared mainly under extreme conditions such as high temperature. Recovery rates of filariform larvae were inversely related to those of females. It was remarkable that high temperature, but not low faecal dilution, affected development of filariform larvae. Although the appearance of free-living males was constant in various environmental conditions, the present study indicated an increase in free-living males with the duration of infection. Thus, it seems that free-living males are already fixed as male in the egg stage, and potential female rhabditiform larvae differentiate into free-living females or filariform larvae depending on environmental factors. There is no marked difference in the development of rhabditiform larvae into filariform larvae in either the immunosuppressed dog or the intact dog.