ABSTRACT
A cohort study was performed to evaluate the incidence and risk factors of Giardia duodenalis infection in an orphanage in suburban area outside Bangkok, central Thailand. Stool specimens were examined for the presence of G. duodenalis in January 2007, May 2007 and January 2008. Of 892 stool specimens from 481 individuals, simple wet preparation, PBS ethyl-acetate sedimentation and PCR amplification of the SSU-rRNA gene were performed to detect G. duodenalis. Using PCR of the glutamate dehydrogenase gene and sequence analysis, G. duodenalis assemblages were identified. Associated risk factors were analysed using Fisher's exact test which revealed significant infection of G. duodenalis in boys and specific rooms where orphans aged 25-48 months old lived. Genotypic characterization of G. duodenalis revealed that assemblage A subtype AII was the most predominant found in orphans living in the specific rooms, thus the transmission was likely to occur via person-to-person. Other modes of transmission were less likely to occur. This study showed that the incidence rate of Giardia infection gradually decreased significantly after the implementation of health education and appropriate treatment of infected orphans.
Subject(s)
Giardia lamblia/isolation & purification , Giardiasis/epidemiology , Orphanages , Child , Child, Preschool , Cluster Analysis , Cohort Studies , DNA, Protozoan/chemistry , DNA, Protozoan/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Feces/parasitology , Female , Genotype , Giardiasis/parasitology , Glutamate Dehydrogenase/genetics , Humans , Incidence , Infant , Male , Molecular Sequence Data , Phylogeny , Polymerase Chain Reaction , RNA, Ribosomal, 18S/genetics , Risk Factors , Sequence Analysis, DNA , Suburban Population , Thailand/epidemiologyABSTRACT
A cross-sectional study was conducted to determine the prevalence and risk factors of Giardia duodenalis infection in 189 preschool children at Sanamchaiket District, Chachoengsao Province, central Thailand in February 2007. Stool specimens were examined for the presence of Giardia using simple wet preparation and PBS-ethyl acetate concentration technique. The prevalence of G. duodenalis in preschool children was 5.8%. Using PCR-RFLP analysis of the glutamate dehydrogenase gene (gdh), genotypes of G. duodenalis revealed assemblage AII (3, 30.0%), BIII (1, 10.0%), and BIV (6, 60.0%). Using multivariate analysis, children who kept cat(s) at home were at 5.1 times (95% CI; 1.3- 20.3) greater risk of acquiring giardiasis. This study possibly represents the information supporting the potential zoonotic transmission of G. duodenalis between cats and preschool children. Unfortunately, in this study, we did not determine G. duodenalis infection in cats, so further studies in cats should be performed to confirm this postulation.
Subject(s)
Giardia lamblia/classification , Giardia lamblia/genetics , Giardiasis/epidemiology , Animals , Child , Child, Preschool , Cluster Analysis , Cross-Sectional Studies , DNA, Protozoan/genetics , Feces/parasitology , Female , Genotype , Giardia lamblia/isolation & purification , Giardiasis/parasitology , Humans , Male , Molecular Typing , Parasitology/methods , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Prevalence , Risk Factors , Rural Population , Thailand/epidemiologyABSTRACT
Currently, the detection of human infection with Blastocystis hominis is usually based on the examination under a light microscope of faecal samples, either directly, as 'simple smears', or after some form of concentration. Whether short-term, in-vitro cultivation would increase the sensitivity of such detection remains a matter of controversy. Over 900 fresh stool specimens, from soldiers in the Royal Thai Army, were each checked for the parasite using three methods: simple smears; formalin-ethyl-acetate concentration; and cultivation in Jones' medium. Although 334 of the samples were found to be culture-positive, the parasites were only detected in 142 of the simple smears, and faecal concentration led to an even lower sensitivity (64 positive samples). In-vitro cultivation does seem worthwhile in the detection of B. hominis carriage in field studies.
Subject(s)
Blastocystis Infections/parasitology , Blastocystis hominis/growth & development , Feces/parasitology , Animals , Blastocystis Infections/diagnosis , Blastocystis hominis/isolation & purification , Culture Media , Humans , Sensitivity and Specificity , ThailandABSTRACT
A prospective study of intestinal microsporidiosis in HIV-positive children was conducted at the Queen Sirikit National Institute of Child Health and Phramongkutklao Hospital, Bangkok, Thailand. Hospitalized HIV-positive children with and without diarrhea were enrolled in this study. Microsporidial spores identified by calcofluor fluorescent and gram-chromotrope stain were confirmed by electron microscopy. As well as Cryptosporidium parvum, Microsporidia was the most common protozoa found in the present study, each was 7.1%. Microsporidia was significantly more common in those who had diarrhea. Intestinal microsporidiosis was found in HIV-positive children with both acute and chronic diarrhea. This study emphasizes the importance of Microsporidia in HIV-infected children. Early detection of microsporidia could be of benefit for the patients, since the infection is treatable.
