Intestinal microsporidiosis: A new entity in Malaysia?

Intestinal microsporidia is an emerging human disease caused by microsporidia. A study was conducted to determine the prevalence of microsporidia in patients with gastro-intestinal symptoms and to examine the clinical manifestations associated with intestinal microsporidiosis. A descriptive cross-sectional study using a well-structured questionnaire; a review of medical records was also undertaken. Positive stool samples were defined as presence of one or more pinkish-violet ovoid structures with a belt-like stripe under high power field (100x) using modified gram-chromotrope stain (MGC). A total of 353 faecal specimens of patients was examined and 100 patients were found to have positive stool samples for microsporidia. The overall prevalence of microsporidia was 28.3%. Acute and chronic diarrhoea were seen in 49.0% and 36.0% patients, respectively. The commonest clinical presentations were diarrhoea (85.0%) with 83.0% of patients having loose or watery stools, vomiting (75.0%), foul-smelling stools (60.0%), nausea (59.0%) and cramping abdominal pain (39.0%). The least common symptoms were fever (15.0%), mucous in stool (5.0%) and blood in stool (4.0%). This study concludes that the prevalence of microsporidia is still high (28.3%) and the majority of patients (93.0%) are symptomatic; the most common gastro-intestinal symptom is diarrhoea with loose or watery stools. Hence, it is recommended that a stool screening for microsporidia be done in selected patients presented with gastrointestinal symptoms.

A recombinant 19 kDa Plasmodium berghei merozoite surface protein 1 formulated with alum induces protective immune response in mice

We investigated the immunogenicity of recombinant rMSP1 (rPbMSP1) that was generated from Plasmodium berghei. The rPbMSP1 formulated in alum was found to be immunogenic which induced high levels of specific anti-rPbMSP1 antibody. The IgG2a response predominated over IgG1 during the challenge infection in the vaccinated mice. Mice vaccinated with rPbMSP1 in alum mounted significant protective immunity against challenge infection (P < 0.01). On day 121 after the booster, three out of ten mice immunized with rPbMSP1 in PBS survived parasite infection (P < 0.05) and eight out of ten mice vaccinated with r MSP1 in alum did (P < 0.01). Hence, immunization with MSP1 in alum obviously has conferred protective effects, which prevented death from P. berghei lethal infection in mice (P < 0.01). These observations provide an excellent model for clinical assessment of this formulation in human subjects.