Prevalence of intestinal protozoan infections among Orang Asli schoolchildren in Pos Senderut, Pahang, Malaysia.

The current study determined the prevalence of intestinal protozoan infections among the Orang Asli schoolchildren in Pos Senderut, Pahang, Malaysia. The overall intestinal protozoan infection rate was 85% (261 out of 307). The highest prevalence rates were due to Entamoeba coli (24.4%), Giardia lamblia (21.8%), Blastocystis hominis (21.2%) and Entamoeba histolytica (15.0%). The prevalence of Iodamoeba butschlii was only 2.9%. Among the positive samples, mixed infection with B. hominis and E. histolytica was 3.3%, B. hominis and G. lamblia was 2.9%, G. lamblia and E. histolytica was 2.0% and triple infections (B. hominis, G. lamblia and E. histolytica) was 1.0 %. The prevalence of the infection was high in all age groups (6-14 years old). Thus, we can conclude that intestinal protozoan infections are still representing a serious public health problem in aboriginal communities, especially among children.

The discrimination of d-tartrate positive and d-tartrate negative S. enterica subsp. enterica serovar Paratyphi B isolated in Malaysia by phenotypic and genotypic methods.

Serotyping is not sufficient to differentiate between Salmonella species that cause paratyphoid fever from the strains that cause milder gastroenteritis as these organisms share the same serotype Salmonella Paratyphi B (S. Paratyphi B). Strains causing paratyphoid fever do not ferment d-tartrate and this key feature was used in this study to determine the prevalence of these strains among the collection of S. Paratyphi B strains isolated from patients in Malaysia. A total of 105 isolates of S. Paratyphi B were discriminated into d-tartrate positive (dT+) and d-tartrate negative (dT) variants by two lead acetate test protocols and multiplex PCR. The lead acetate test protocol 1 differed from protocol 2 by a lower inoculum size and different incubation conditions while the multiplex PCR utilized 2 sets of primers targeting the ATG start codon of the gene STM3356. Lead acetate protocol 1 discriminated 97.1% of the isolates as S. Paratyphi B dT+ and 2.9% as dT while test protocol 2 discriminated all the isolates as S. Paratyphi B dT+. The multiplex PCR test identified all 105 isolates as S. Paratyphi B dT+ strains. The concordance of the lead acetate test relative to that of multiplex PCR was 97.7% and 100% for protocol 1 and 2 respectively. This study showed that S. Paratyphi B dT+ is a common causative agent of gastroenteritis in Malaysia while paratyphoid fever appears to be relatively uncommon. Multiplex PCR was shown to be a simpler, more rapid and reliable method to discriminate S. Paratyphi B than the phenotypic lead acetate test.