Cryptosporidiosis among children with diarrhoea in three Asian countries: A review

This review focuses on studies concerning cryptosporidiosis in three Asian countries. Cryptosporidium spp. infection was investigated in children < 12 years old afflicted with diarrhoea and admitted to the paediatric hospitals in Iraq, Jordan and Malaysia. Most of the patients complained of abdominal pain, watery diarrhoea and mild-to-severe dehydration. Stool samples were collected from children and five methods were used to detect oocysts of Cryptosporidium spp. including: direct wet mount, Sheather's sugar flotation, formalin-ether sedimentation, modified Ziehl-Neelsen and direct fluorescent antibody (DFA). The infection rate was 8.56, 37.3 and 4.6 in Iraq, Jordan and Malaysia, respectively. A combination of formalin ether sedimentation and acid fast stain was used to detect Cryptosporidium oocysts in Iraq. The DFA test showed the highest sensitivity for samples of children in Jordan. In Malaysia, direct wet mount, formalin-ether sedimentation, modified Ziehl-Neelsen and DFA gave the same results (4.62%) while Sheather's sugar flotation was 3.85%. Source of drinking water appeared to be an important risk factor in transmission of infection. In Jordan, the high rate of infection was recorded in rainy season (January-May).

Ability of Acanthamoeba Cyst to Excyst at Different Temperatures / Jurnal Sains Kesihatan Malaysia

This study was carried out to observe thermotolerance ability of Acanthamoeba spp. A total of 32 Acanthamoeba spp. isolates obtained from water taps, sinks, swimming pools and sea water were used. Trophozoites of Acanthamoeba spp. were inoculated onto non-nutrient agar (NNA) seeded with heat-killed Escherichia coli using aseptic technique and incubated for 14 days at 30°C to obtain the cyst. The cysts were subcultured onto new agar plates for thermotolerance test at 37°C and 42°C. The plates were observed until 96 hours after incubation for excystation of Acanthamoeba before being declared negative. Overall, 81.25% of samples were able to excyst at 37°C while 37.5% were able to excyst at 42°C. Thermotolerant Acanthamoeba is associated with high pathogenicity potential.

Isolation of Acanthamoeba spp. from Aquatic Environment / Jurnal Sains Kesihatan Malaysia

This study was carried out to isolate Acanthamoeba spp. from various aquatic environments in Peninsular Malaysia. A total of 160 samples were collected with 140 samples using direct swab method and 20 samples using water collection method with 500 ml sterile Schott bottle. The swab samples were taken from water tap (50), sink (50), and swimming pool (40) while the water samples were from seawater. Swab samples were inoculated directly onto non-nutrient agar (NNA) seeded with heat-killed Escherichia coli using aseptic technique. Water samples were first filtered through a 0.45μm pore size membrane before the membrane was transferred aseptically onto NNA plate seeded with heat-killed E. coli. All plates were incubated at 30°C and examined daily for the presence of Acanthamoeba spp. up to 14 days after incubation before being declared negative. Overall, 20% samples were positive for the presence of Acanthamoeba. Positive isolation of Acanthamoeba spp. from sink and swimming pool were 20% and 30%, respectively. All three groups of Acanthamoeba genus in cyst form could be found from the collected samples.