Prevalence of intestinal parasitic infections among school children in the central region of Thailand.

OBJECTIVE: Survey the prevalence of intestinal parasitic infections in 14 primary schools of Central Thailand. MATERIAL AND METHOD: A cross sectional survey of the prevalence of intestinal parasitic infections in 14 primary schools of Central Thailand that included Ang Thong, Ayudthaya, and Suphanburi provinces was conducted One thousand and thirty seven children with age ranging from 3-12 years (540 males and 497 females) were examined for intestinal parasites by the formalin-ether concentration technique. RESULT: The overall prevalence was 4.24%. The pathogenic parasites found were Giardia lamblia (1.25%), Enterobius vermicularis (0.19%), Trichuris trichiura and Hookworm (0.19% each), respectively. The common non-pathogenic protozoa found were Entamoeba coli (1.64%) and Endolimax nana (0.48%). The infection rate of Blastocystis hominis was 0.19%. CONCLUSION: Interestingly, the area studied which is low and flat and contains rice and water chestnut fields and small rivers, did not demonstrate Fasciolopsis buski as highly found in the past five decades. However, Parasittic infections are still public health problems in Thailand Close monitoring and control of parasitic infections is needed

Pneumocystis jiroveci in HIV/AIDS patients: detection by FTA filter paper together with PCR in noninvasive induced sputum specimens.

OBJECTIVES: To detect P. jiroveci (previously named P. carinii) by PCR using FTA filter paper to extract the DNA, from noninvasive induced sputum samples of HIV/AIDS patients. MATERIAL AND METHOD: Fifty two HIV/AIDS patients suspected of Pneumocystis jiroveci pneumonia (PJP) in King Chulalongkorn Memorial Hospital were recruited. Both cytological method and PCR with FTA filter paper technique were performed to detect P jiroveci from each specimen. RESULTS: The detectability rate of P. jiroveci infection was 21%. The PCR with FTA filter paper method was 4 folds much more sensitive than Giemsa staining technique. P. jiroveci was detected in 18% of the HIV/AIDS patients in spite of receiving standard PJP prophylaxis. CONCLUSION: Detection of P. jiroveci by using FTA filter paper together with PCR in induced sputum samples could detect more cases of P. jiroveci infection than by using cytological method. DNA extraction using the FTA filter paper was more rapid and convenient than other extraction methods. The causes of failure of PJP prophylaxis should be evaluated.

Prevalence of parasitism among students of the Karen hill-tribe in Mae Chame district, Chiang Mai province, Thailand.

Infection caused by intestinal parasites is still a common health problem in a poor-hygiene population especially for children in developing countries. A cross-sectional study was conducted among 781 Karen students (age: 3 to 19, males: 325, females: 456) to determine the current status of intestinal parasitic infections in a mountainous area in the North of Thailand. The study was drawn from three schools in the Doi Inthanon region, in Mae Chame district of Chiang Mai province, from December 2002 to June 2003. The techniques used for the diagnosis were: stool concentration by using the 'formalin-ether' technique and perianal region examination by using the 'Scotch-tape' technique. The average rate of intestinal parasites for the group tested using the stool concentration technique was 42.06% (male: 46.87%, females: 38.82%); and 22.66% (males: 28.92%, females: 18.20%) when using the Scotch-tape technique.Among helminth-infected individuals, enterobiasis was found at the highest prevalence (15.49%). Other common infections were ascariasis (9.78%), trichuriasis (5.90%) and hookworm infection (2.20%). Strongyloildiasis was found only in 0.92%. For protozoa infection, the major cause is the non-pathogenic species "Entamoeba coli" (27.68%). The other non-pathogenic protozoa (Endolimax nana, Chilomastix meslini and Iodamoeba butschlii) had a low prevalence from ranged 0.18%-4.79%. The prevalence of pathogenic Giardia lamblia infection was 2.21%. Entamoeba histolytica infection was found in only one case. Based on the two techniques used, the results from the Scotch-tape provided a higher sensitivity for the detection of Taenia spp. and Enterobius vermicularis eggs. Drug treatment was given to all the infected students. School-based health education should be implemented in order to prevent and control the infections.

Preparation of Gnathostoma protein by ultrafiltration method using Nanosep membrane.

We report our experience with Gnathostoma protein preparation by the ultrafiltration method. Crude antigen was sonicated and ultrafiltrated using the Nanosep 100 K membrane. SDS-PAGE electrophoresis showed protein bands at 43, 41, 24, 22, 21, 19.5 kDa. Use of the ultrafiltration method can provide specific protein (24 kDa), similar to the non-ultrafiltration method, with the other 5 non-specific proteins. Using the non-ultrafiltration method, there were more (20) non-specific protein. The ultrafiltration method can be an alternative method for the preparation of protein, which can provide better results than non-ultrafiltration.

Intestinal parasitic infestations among children in an orphanage in Pathum Thani province.

Infection caused by intestinal parasites is still a common health problem especially in children from developing countries. Orphans are a group of underprivileged population in society. To evaluate the intestinal parasitic infections in children in an orphanage in Pathum Thani province, Thailand, stool samples were collected during a cross-sectional study in April 2001. Examination for intestinal parasites were performed by using simple smear, formalin-ether concentration, Boeck and Drbohlav's Locke-Egg-Serum (LES) medium culture and special staining (modified acid-fast and modified trichrome) techniques. A total of 106 pre-school orphans (60 males and 46 females), aged 10.0-82.0 months, were recruited for the study. There were 86 individuals (81.1%), 45 males and 41 females, infected with at least one parasite. Interestingly, most of the parasites identified were protozoa. Blastocystis hominis was found at the highest prevalence (45.2%). The infections caused by Giardia lamblia was 37.7 per cent and Entamoeba histolytica was 3.7 per cent. Other non-pathogenic protozoa found were Trichomonas hominis (39.6%), Entamoeba coli (18.8%), and Endolimax nana (3.7%). The only one case of helminth parasite detected was Strongyloides stercoralis (0.9%). The sensitivity for detection of B. hominis and T. hominis was increased by the LES culture technique. No history of diarrhea symptoms were recorded among these orphans. However, during the investigation, stools of all infected cases were noted for six characteristics including formed, soft, loose, mucous, loose-watery and watery. The present study emphasized the problems of protozoan infections among these orphans. Health educations as well as routine surveillance is necessary in order to control the infections.

Comparison of methods for identification of Pneumocystis carinii in bronchoalveolar lavage fluid.

Pneumocystis carinii pneumonitis in one of the most common life-threatening opportunistic infections in patients with AIDS. The definitive diagnosis of this infection can be established only by demonstration of the organism in clinical specimens. This study was a comparison of methods that provide easy recognition of the organism which is readily available, simple and can be performed rapidly in laboratory-diagnosis. Bronchoalveolar lavage fluids obtained from 35 AIDS patients suspected of having Pneumocystis carinii pneumonitis were examined by three staining methods for the presence of Pneumocystis carinii. With Giemsa stains, P. carinii could be identified in 18 cases (51.4%). Three developmental stages: "cyst", "sporozoite" and "trophozoite" were seen. The contrast of organisms against host cells was not outstanding in these stains. Toluidine blue O stains provided easy recognition of the organisms, with marked contrast between the cysts and host cells. 21 cases (60%) were positive in these stains, but the intracystic structures and trophozoites could not be identified. It was suggested that the clinical specimen should be stained first with toluidine blue O which is more rapid and permits easy recognition of the cyst clusters. If the sporozoites and trophozoites had to be identified, Giemsa stains can be made. In addition, with the methenamine silver nitrate stains, 21 cases (60%) were positive. They revealed the morphology as seen with toluidine blue O but the cost of material may make it unavailable in many laboratories especially with the budgetary restraints of developing countries.

A prevalence of Cryptosporidium infections among Thai HIV-infected patients.

The prevalence of Cryptosporidium in 156 HIV-infected Thai patients who had acute diarrheal illness at Bamrasnaradura Infectious Diseases Hospital, was studied. This cross-sectional study was performed from March to August in year 2001. The patients ranged in age from 1 month-65 years old. A stool sample from each subject was stained to find the oocysts by modified Ziehl Nelson carbolfuchsin staining. According to the present study, a diagnosis of Cryptosporidium parvum infection was found in 20 patients (11 males and 9 females). The prevalence of cryptosporidiosis in the present series was 12.8 per cent (10.0% in males and 19.1% in females). This infection rate between males and females was not significantly different. Comparing this prevalence to a report in the previous 5 years in the same hospital, the same high rate can be seen.

Prevalence and intensity of third stage Gnathostoma spinigerum larvae in swamp eels sold in three large markets in Bangkok, Thailand.

Gnathostoma spinigerum is a common human tissue parasite in Thailand. The swamp eel is the major intermediate or paratenic host for this parasite. The high prevalence of the infective third stage larvae (L3) of this parasite in the rainy season has been noted in previous studies. During June 1999 (rainy season), we performed a cross-sectional survey of the prevalence and the intensity of G. spinigerum L3s in the livers of swamp eels that were obtained from three large Bangkok markets (Klong Toey, Pran Nok, and Tevej). Of a total of 785 livers, G. spinigerum L3s were found in 97: an infection rate of 12%. The prevalence rates in Klong Toey, Pran Nok, and Tevej markets were 13%, 10% and 14% respectively. There was no significant difference in the proportion of infected eels between the markets (p > 0.05). The intensity of L3 burden in the livers ranged from 1-17 larvae, with an average of 2.60 +/- 0.24 larvae (mean +/- SE). In this study a high prevalence of G. spinigerum L3s was found; there was no significant difference in the intensity of larvae in swamp eels between markets. These findings emphasize the importance of public health education: people need to be aware of the dangers of consuming raw or undercooked food.

Parasitic infections in Thai workers that pursue overseas employment: the need for a screening program.

Stool examination is a requirement of the screening program for Thai workers seeking overseas employment. We report on the prevalence of intestinal parasitic infections among these workers; the stool examination results of 2,213 Thai workers who visited the Out-patients Department of the King Chulalongkorn Memorial Hospital between September 2000 and January 2001 were analysed. One hundred and thirty-five (6.1%) were found to be infected with 1 or 2 species of parasite. There were 54 (40%), 47 (34.8%), and 25 (18.5%) cases infected with nematodes, platyhelminths and protozoa, respectively. The commonest parasite was Opisthorchis viverrini (28.9%). Most nematode infections were due to Strongyloides stercoralis (19.2%); most protozoal infections were due to Giardia lamblia (17.0%). Mixed infections were found in 9 cases. Not unexpectedly, the rate of intestinal parasitic infection among Thai workers remains high. Screening for the parasitic infections among these workers can help to decrease their rate of rejection by the countries in which overseas employment is sought.