Stool examination, height and weight measurements were undertaken on 249 early primary school children at two schools in North-eastern Peninsular Malaysia. Helminth infected children were treated and follow-up anthropometric measurements and stool examination undertaken on all (n = 100) children at one of the schools 16 months later; to observe the relationship between acquisition of infection and growth. Baseline Ascaris prevalence rates at the two schools were 16.0% (23/144) and 47.6% (50/105) respectively whilst Trichuris rates were 33.3% (48/144) and 52.4% (55/105). Hookworm infection was uncommon. There was no difference in weight or height for age between infected and uninfected children at any time. Acquisition of worm infection over the initial 16 month follow-up period was not associated with significant decreases in growth rates. However the small subsets of children with heavy Ascaris infection were consistently lighter and shorter at all evaluation times. They also gained significantly less weight and tended to have reduced linear growth rates between measurements. Further interventional studies are required to determine if this association is one of cause and effect or largely incidental.
Blastocystis sp. is a gastrointestinal (GI) protozoan parasite reported to cause non-specific GI symptoms including diarrhea, flatulence, abdominal pain, and nausea. Complete eradication of Blastocystis sp. is rather challenging even with the drug of choice, i.e., metronidazole. Here, we report on two Blastocystis sp.-infected individuals, who presented increased parasite load and exacerbated symptoms upon treatment with the usual recommended dosage and regime of metronidazole. The two studies uniquely demonstrate for the first time a cyst count as high as fivefold more than the original cyst count before treatment and show an exacerbation of GI symptoms despite treatment. The study provides additional support in recognizing metronidazole resistance in Blastocystis sp. and its consequences towards the pathogenicity of the parasite.