Growth and development four years after treatment for the Trichuris dysentery syndrome

A follow-up study is reported of 18 children 4 y after treatment for the Trichuris dysentery syndrome (TDS) and matched control children. The TDS children were initially severely stunted and had extremely low developmental levels. They showed catch-up in height of 1.9 z-scores even though they remained in very poor environments. Their intelligence quotients, school achievement and cognitive function remained significantly lower than those of the controls. Controlling for their earlier developmental levels, the TDS children showed a small improvement in mental development relative to the controls (Au)

Treatment effects in trichuris dysentery syndrome

Heavy infection with geohelminth trichuris trichiura causes the Trichuris dysentery syndrome (TDS). Growth retardation and anaemia are charcteristic of TDS and both are associated with poor development. We have examined the growth and developmental responses to treatment in 19 children aged 27-84 months with TDS. Development levels (DQ) were measured with the Griffiths mental development scales. Compared with a control group matched for age, gender and neighbourhood, the TDS children initially had serious deficits in DQ (24 points, p < 0.001). After a year of anthelmintic treatment, the TDS children showed improvement in locomotor development (p<0.001) compared with the controls. The TDS children also had initial deficits in height-for-age, weight-for-height, mid upper arm circumference and haemoglobin levels. They caught up rapidly in indices of wasting (weight-for-height and mid-upper arm circumference) and showed steady improvement in height-for-age and haemoglobin levels. Catch-up in height was comparable to that of children recovering from coeliac disease. The importance of continuing prevention after initial treatment is highlighted (AU)

Growth suppression in the Trichuris syndrome

The Trichuris Dysentery Syndrome (Ramsey, 1962) is an insidious, chronic condition which has clinical features similar to Chron's ileocolitis and ulcerative colitis, disease similarly associated with growth retardation. The attained heights and weights of 19 children at the time of diagnosis of intense, symptomatic Trichuris (whipworm) infection showed and average height of -2,4 Standard Deviation (Z) scores from the Tanner-Whitehouse median with weight, adjusted for height-age, -1.3 Z. We present data on the growth velocities of 11 of the children, in the half-year following worm explusion by mebendazole. These children returned to their home environment without food supplementation or close follow-up, but showed and average height velocity of + 5.5 Z and weight velocity (for height-age) of + 2.4 Z. Of 8 children with unequivocal height spurts only 3 had any weight spurt. We suggest that the pattern of catch-up growth points to the existence of some specific link between allergy or inflamation in the lower intestinal tract and suppression of linear growth, rather than to stunting due to general deprivation and undernutrition. (AU)

Predisposition to Trichuris trichiura infection in humans

The study examines the distribution of Trichuris trichiura infection in a village community in St. Lucia, West Indies. The infection intensity of the same age-stratified population was assessed (by drug expelled worm burden and faecal egg count) at the intiation of the study, and after 17 months of reinfection following treatment. The frequency distribution of worm numbers per person was similar at both periods of sampling. There was a significant correlation between the initial infection intensity of an individual, and the intensity acquired by the same individual following the 17 month period of reinfection. This relationship was observed in a broad range of host age classes. The study provides firm evidence that individuals are predisposed to heavy (or light) T. trichiura infection. (Summary)

Whole gut irrigation in strongyloidiasis - abstract

Two patients with chronic Strongyloidiasis, refractory to conventional therapy, were studied by whole gut irrigation and high-dose antihelminthic therapy. Saline (0.9 percent) was given via naso-gastric tube at 50 ml per minute. After solid material was cleared, the gut effluent was collected in 10-minute samples. After one hour baseline collection, mebendazole (1,800 mg in patient 1) or levamisole (1,100 mg in patient 2) was given. Irrigation and collection continued for a further 140 and 170 minutes respectively. Parasitic forms were collected and counted in each sample. In the mebendazole treated patient the spontaneous egg- and larval-shedding rate was 1,501/minute. This was not affected by mebendazole treatment. Adults first appeared in the effluent at 1 hour after treatment and the numbers were increasing at the termination of the infusion. Nineteen adults were recovered. Follow-up showed no diminution in the intensity of infection, demonstrating that only a small proportion of the available adults had been recovered or expelled. In the levamisole treated patient, the pre-treatment effluent contained 49,041 larvae/minute and no adult forms. In contrast to mebendazole, after treatment with levamisole, there was a massive efflux of adults which had not returned to baseline after 3 hours; 88,729 adults were recovered. The post-treatment infection level was reduced dramatically and a further 15,000 adults were recovered within 24 hours. There was no increase in larval output with levamisole. It is concluded that neither mebendazole nor levamisole has a direct on Strongyloides larvae. However, they are both active against the adult forms, with the potency of levamisole appearing to be greater than that of mebendazole. Treatment with these drugs may have to continue for longer than the full maturation time of endogenous larvae. This may be in excess of 4 weeks (AU)

Population distribution of Trichuris trichiura in a community of Jamaican children

The trichuris trichiura worm burdens of 23 children in a Place-of-Safety in Kingston, Jamaica were assessed by stool collection for more than five days after treatment with mebendazole. This procedure was repeated after a seven-month period of natural reinfection. For both collections the maximum rate of worm expulsion was achieved on the fourth day after starting treatment. The worm populations were overdispersed and well described by the negative binomial probability model (k=0.29) in each case. For any one individual, the number of worms passed on the first expulsion was unrelated, absolutely or relatively, to the number passed on the second. These data suggest that: knowledge of the time dependency of helminth expulsion is essential for the accurate determination of worm burdens by this method; populations of Trichuris are more highly aggregated than those of Ascaris and thus may be more susceptible to control by selective rather than random chemotherapy; and the inherent predisposition of hosts to infection may be of minor importance in determining the distribution of worms in the population-heavily infected hosts appear no more or less likely to acquire large worm burdens on subsequent exposures. (AU)

Population dynamics and chemotherapeutic control of Trichuris trichiura infection of children in Jamaica and St. Lucia

Population dynamical parameters of Trichuris trichiura infections in children were estimated from longitudinal intensity and prevalence data from a population (n=23) in a children's home in Jamaica. The theoretical predictions of a deterministic model incorporating these parameters were approximated to observe horizontal-age prevalence data from a naturally infected population (n=203) of children in a St. Lucian village, and a rough estimate of the basic reproductive rate (Ro=8-10) of T. trichiura obtained. The findings suggest that T. trichiura populations are intrinsically more difficult to control by traditional mass-treatment chemotherapy (eradication requires >91 percent of the population to be treated every 6 months for >5 years) than are populations of Ascaris, but may be more susceptible to selective chemotherapy programmes which aim to treat only the most heavily infected individuals (AU)