Morphological characteristics of microfilariae in blood smears of the common treeshrew Tupaia glis (Mammalia: Scandentia) in Gemas, Negeri Sembilan, Malaysia

@#Some filarial nematodes, such as Wuchereria bancrofti, Brugia malayi, and Brugia timori, cause lymphatic diseases in humans in the tropics, whereas other filarial parasites from wild animals cause zoonotic diseases in humans worldwide. To elucidate the prevalence and diversity of filarial parasites in Malaysia, we investigated the filarial parasites from wild animals in Gemas, Negeri Sembilan. To find adult filarial parasites, we dissected 26 animals, which included five frogs, one skink, one snake, two birds, six common treeshrews, and 11 rats. Then, we examined microfilariae in the blood smears and skin snips obtained from each animal. We found two types of microfilariae in the blood smears of common treeshrews: one was very similar to Malayfilaria sofiani and the other closely resembled Brugia tupaiae. These findings indicate an additional distribution of these filarial parasites in Gemas.

Aqueous dynamics and histopathological effects of phakic posterior chamber intraocular lens

Purpose: detection of pathological effects and aqueous dynamics of phakic posterior chamber ICL

Design: prospective noncompetitive experimental study

Methods: WE investigated histopathologic ally the effects of phakic posterior chamber intraocular lens [PPC IOL , Staar Surgical ICL] on the crystalline lens and t/aqueous dynamics on eighteen operated pig's and rabbit's eyes, that underwent ICL implantation and the other eye as a control, after post-operative follow up for three to six months

Results: the PPCIOL causes an obstacle for aqueous dynamics using both anterior chamber and vitreous approaches in ten out of 18 cases [55.6%] and also by 'dissecting microscope photo and histopathological study the same number of eyes had cataractous lens changes

Conclusion: the ICL causing some sort of obstruction to the aqueous dynamics leads to disturbance in lens metabolism, pathological changes in the epithelial cells] and cortical fibers [early cataractous changes]

Seasonal distribution of enteropathogens detected from diarrheal stool and water samples collected in Kathmandu, Nepal.

A total of 334 diarrheal fecal samples (from 210 males and 124 females) collected in Kathmandu, Nepal, were studied for various kinds of enteropathogens. Overall, 33% (111/334) fecal samples were positive for one or more enteropathogens. There was no difference in detection rates between males and females. Enteropathogen detection rates in summer, winter, spring, and autumn were 61% (40/66), 52% (45/87), 31% (25/81), and 25% (25/100), respectively. Altogether eight species of bacteria, three genera of viruses, and five species of protozoan parasites were detected with considerable seasonal variations. Among the bacterial isolates, enteropathogenic Escherichia coli topped the list followed by Vibrio sp. Only one sample had Shigella (S. sonnei). Rotavirus type A was the most frequently detected among the enteric viruses, followed by human enterovirus and human adenovirus, respectively. Among the enteric protozoan parasites, Giardia intestinalis was the most frequently detected followed by Cryptosporidium parvum. Detection of bacterial and protozoan pathogens showed a slightly high tendency in the summer season compared with that in the other seasons (p>0.05), whereas the detection of viruses was significantly high in the winter season (p<0.05). Of the total 57 water samples, 43 (75%) showed one or more bacterial species out of which 51% (22/43) were E. coli. Among the E. coli isolates, 68% were EPEC. Enterohemorrhagic E. coli (O157) was not detected.

Contamination of soil with helminth parasite eggs in Nepal.

Contamination of soil with helminth eggs in Kathmandu Valley (n=122) and outside of Valley (n=34) in Nepal was investigated with the use of centrifugal floatation technique using sucrose solution (sp gr 1.200). The overall soil contamination rate was 36.5% (57/156). The prevalence was uniform in Kathmandu Valley (36.9%) and outside of the valley (35.3%). A mean of six helminth eggs per sample were detected out of which more than half were embryonated (potentially infective). In Kathmandu Valley, soil contamination rate was higher (48.3%) during wet season compared with that observed in dry season (33.3%) but without significant difference (p>0.05). Multiple species of helminth eggs were detected in 22.8% of total positive samples (n=57). Altogether five species of nematoda (Ascaris lumbricoides, Toxocarta sp, Trichuris trichiura, Capillaria sp and Trichostrongylus sp) and two species of cestoda (Hymenolepis nana and H. diminuta) were recovered. A. lumbricoides was predominant in Kathmandu Valley while Trichostrongylus was the commonest one in outside of valley.

Soil contamination and infections by soil-transmitted helminths in an endemic village in southern Thailand.

The aim of this study was to test the association between soil contamination and infection of the household members by soil-transmitted helminths in dry and rainy seasons. A lake-side community in southern Thailand with a population of 2,340 was studied twice, in the dry season and rainy season of 1995. Fifty households were randomly selected. Soil samples near the latrine, in the yard, at the foot-washing area and under the trees were taken and analysed for presence of helminthic eggs. All members of the selected household were interviewed and stool samples obtained. Age-adjusted odds ratios of presence of Ascaris and Trichuris eggs in the household soil for ascariasis and trichuriasis were 10.5 (95% CI 1.5-77.1) and 5.5 (95% CI 2.4-12.7) in dry season and 10.4 (95% CI 2.5-43.8) and 8.3 (95% CI 3.4-20.0) in rainy season. The levels of hookworm eggs detected in the soil were too low to test the association. Soil analysis for eggs of Ascaris and Trichuris may be used to predict infections among the household members but not that for hookworm.

Toxoplasma antibody prevalence in Nepalese pregnant women and women with bad obstetric history.

Sera from randomly selected 345 pregnant Nepalese women aged 16-36 years and 13 women with bad obstetric history (BOH) were tested for the presence of Toxoplasma antibodies using microlatex agglutination (MLA) and ELISA methods. The overall prevalence was 55.4% (191/345). Prevalence was slightly higher (59.0%) in older age-group (27-36 years) compared with younger age-group (16-26 years) (52.2%). No significant difference in antibody prevalence in women belonging to two different ethnic-groups (Tibeto-Burmans 57.8%, Indo-Aryans 52.7%) was observed (p>0.05). MLA antibody titer ranged from 1:16 to 1:2,048. Over three-fourth of the women showed either high (1:510 or over) or low (1:16 or 1:32) antibody titer. Three percent (6/191) of MLA antibody positive subjects had Toxoplasma IgM antibodies by IgM-ELISA. All six IgM antibody positive pregnant women had MLA antibody titer of over 1:510. Of the total 13 women with BOH, 5 (38.5%) had Toxoplasma antibodies of which 2 (40.0%) were positive for Toxoplasma-IgM antibodies.

Cryptosporidium infection in HIV-seropositive and seronegative populations in southern Thailand.

The prevalence of Cryptosporidium infection in 61 HIV-seropositive and 61 HIV-seronegative subjects (aged less than one to 67-year-old) in Songkhla City, southern Thailand was studied by a centrifugal flotation technic using sucrose solution. Most of the HIV-seropositive subjects (72%) were 20 to 39 years old. Cryptosporidium oocysts were detected in 10% (6/61) of HIV-seropositive and in 2% (1/61) of HIV-seronegative subjects. Infection rates in these two groups, however, were not statistically significant (p > 0.05). The number of Cryptosporidium oocysts observed in 20 microscopic fields ranged between one and over 12,000. Among the seven Cryptosporidium-positive subjects, six were adults (18 to 42-year-old) and one was three-year-old child. All of the Cryptosporidium infected subjects were male, and two of them were passing formed (normal) feces. Biochemical findings revealed dishepatica in five of six Cryptosporidium infected HIV-seropositive subjects.

Use of polymerase chain reaction in the diagnosis of toxocariasis: an experimental study.

In this paper we report the usefulness of polymerase chain reaction technique in the diagnosis of visceral larva migrans in a mouse model. Liver samples obtained from two set of experimentally infected mice (10, 100, 1,000 and 10,000 embryonated Toxocara canis eggs per mouse) along with the eggs of T. canis, T. cati and Ascaris suum were included in this study. Polymerase chain reaction (PCR) was performed using Toxocara primers (SB12). The first PCR product electrophoresis revealed very thin positive bands or no bands in liver samples. However, on second PCR a clear-cut bands were observed. No positive band was shown by A. suum eggs. Our findings thus indicate the usefulness of PCR technic in the diagnosis of visceral larva migrans (VLM) in liver biopsy materials specifically by means of double PCR using the primer SB12.

Contamination of soil with parasite eggs and oocysts in southern Thailand.

Soil contamination with parasite eggs and oocysts was surveyed in southern Thailand in December 1994 and September 1995. The survey areas were Hat Kai Tao Village in Phatthalung Province and a slum area in a city of Songkhla Province. We used a modification of the centrifugal floatation technique with sucrose solution (specific gravity, 1.200) to recover helminth eggs and protozoa oocysts. Overall, 10 genera and 11 species of parasite eggs and oocysts were recovered. They included eight species of nematoda eggs, one species of cestoda eggs, and two species of protozoan oocysts. The definitive hosts of these parasites are dogs, cats, sheep, lizards, humans, etc. The contamination rates in two areas at different occasions varied from 55% to 72% with an average of 64%. Contamination rates of Hat Kai Tao Village in beginning and end of the rainy seasons were 72%, and 55%, respectively. Although the contamination rate in the end of rainy season was higher than that in beginning of the rainy season, the difference was not statistically significant (p > 0.05). Of the 11 parasites recovered, six were infective to humans, of which, Trichuris trichura, Ascaris lumbricoides, and Toxocara species were predominant. The mean numbers of these eggs recovered in each test were more than 10. Therefore, the contamination was estimated to be more than an egg per gram of soil sample based on the recovery efficiency (40%) of this test. These results suggested that the soil in some parts of southern Thailand may be heavily contaminated by both animal and human feces.

Seroepidemiological study of Toxoplasma infection in central and western regions in Nepal.

The present study was carried out to ascertain the seroprevalence rate in different geographical areas in Central and Western Regions in Nepal. A total of 1,237 serum samples collected from Nuwakot (217), Kathmandu valley (402) and Chitawan (159) districts in Central Region, and Mustang (143), Surkhet (64) and Banke (252) districts in Western Region in Nepal were included in this study. Toxoplasma antibodies were detected by micro-latex agglutination (MLA) and enzyme linked immunosorbent assay (IgM-ELISA) methods. The seropositive rate in Central and Western Regions were found to be 48% and 49%, respectively; with an overall positive rate of 48 percent. Districtwise, the seropositive rate in Nuwakot, Kathmandu valley, Chitawan, Mustang, Surkhet and Banke districts were 38, 46, 64, 51, 67 and 44%, respectively. Interestingly, the relatively newly inhabited Surkhet district in Western Region and Chitawan district in Central Region showed significantly higher seropositive rate compared with those of two other districts in the respective Regions (p < 0.05). Ethnically, Tibeto-Burmans showed higher seropositive rates in Central Region (p > 0.05). In contrast, Indo-Aryans showed higher seropositive rate in Western Region (p > 0.05). Age related increase in seropositivity was observed only in Central Region. One percent of Toxoplasma antibody positive samples also showed Toxoplasma IgM antibody positivity.

Seroepidemiology of five major zoonotic parasite infections in inhabitants of Sidoarjo, East Java, Indonesia.

We conducted a seroepidemiological survey of zoonotic parasite infection in inhabitants of East Java, Indonesia. The subjects of the survey were 244 persons selected from visitors to Sidoarjo City Hospital in East Java between May 1992 and October 1993. Ninety-seven had diarrhea and the rest came to the hospital for routine check-ups. All serum samples were tested for antibodies against five zoonotic parasites: Toxoplasma gondii, Entamoeba histolytica, Toxocara canis. Angiostrongylus cantonensis, and Anisakis species. Tests used were enzyme-linked immunosorbent assays (ELISA), latex agglutination (LA) test, indirect fluorescence antibody (IFA) test, hemagglutination (HA) test, and gel diffusion precipitation (GDP) test. Some 64% of the subjects had antibodies to T. gondii. The prevalence of antibodies to E. histolytica varied from 2 to 15% depending on the test, but the true rate was probably the 7% or 8% obtained by the HA and IFA tests. The proportions of subjects with positive results were 63% for T. canis, 17% for A. cantonensis, and 11% for the Anisakis spp. The prevalence of antibodies to T. gondii and T. canis was lower in subjects aged 1 to 9 years than in older subjects, probably because the persons in this group had less time to be infected. Antibody titers to A. cantonensis and the Anisakis spp. were high in the juvenile group, perhaps because recent changes in eating habits have increased opportunities for infection.

Seroepidemiological study of Toxocara infection in Nepal.

Seroepidemiological study of Toxocara infection in Nepalese people aged more than fourteen years was carried out by enzyme linked immunosorbent assay (ELISA) using T. canis soluble embryonated egg antigen. Of the total 200 subjects included in this study, 162 (81%) were found to possess antibodies to Toxocara spp. Males showed higher (85%) antibody positive rates than females (77%). Inhabitants of Kathmandu valley showed higher antibody positive rates (84%) compared with those living outside of the valley (78%). These differences, however, were not significant statistically (p > 0.05). Ethnically, Newar, Rai/Limbu, Tamang/Sherpa, Brahmin/Chhetri, Jha/Yadavs, and others (Kami, Damai) showed Toxocara antibody positive rates of 85, 85, 83, 70, 77 and 100%, respectively. Half of the Toxocara antibody positive subjects (49%) showed an elevated level (two plus) of antibody.

Contamination of soil with parasite eggs in Surabaya, Indonesia.

Soil was examined for contamination by parasite eggs in Surabaya Indonesia. Surveys were carried out on three occassion; July, 1993 (dry season), March, 1994 (rainy season), and August, 1994 (dry season). Throughout the study, five species of nematode eggs (Ascaris lumbricoides, Toxocara cati, Trichuris trichiura, Physaloptera sp, Capillaria sp), two species of cestode eggs (Hymenolepis diminuta, Spirometra erinacei), and one species of protozoa oocyst (Isospora felis) were detected. The contamination rate and number of species found from the soil were significantly different in the dry and rainy seasons. In the dry season, the prevalence was 8-20%, with two to four species detected. During the rainy season, this rate was 83% with eight species, suggesting parasite infection to possibly occur mainly in this season. The reason for this seasonal difference may be that, in spite of constant temperature around 27 to 29 degrees C throughout the year, rainfall in the dry season in only a few percent of that of the rainy season. We concluded that parasite eggs die during the dry season owing to dryness of the soil. Contamination of soil with parasite eggs and the number of species found were greater in alley-ways and at communal water supply sites around residential areas than in open-air parks or sandy beaches. The method used in the present study proved extremely effective for ascertaining the actual dynamics of parasite infection in a certain region.