Plasma albumin concentrations and intestinal permeability in Bangladeshi children infected with Ascaris lumbricoides

Subclinical Enteric Parasitic Infections and Growth Faltering in Infants in São Tomé, Africa: A Birth Cohort Study

The associations between enteric pathogenic parasites and growth in infants in São Tomé were explored using a refined anthropometric approach to recognize early growth faltering. A birth cohort study was conducted with follow-up to 24 months of age. Microscopic examination for protozoa and soil-transmitted helminths was performed. Anthropometric assessments included: z-scores for weight-for-length (WLZ), length-for-age (LAZ), weight (WAVZ) and length velocities (LAVZ), length-for-age difference (LAD), and wasting and stunting risk (≤-1 SD). Generalized additive mixed effects regression models were used to explore the associations between anthropometric parameters and enteric parasitic infections and cofactors. A total of 475 infants were enrolled, and 282 completed the study. The great majority of infants were asymptomatic. Giardia lamblia was detected in 35.1% of infants in at least one stool sample, helminths in 30.4%, and Cryptosporidium spp. in 14.7%. Giardia lamblia and helminth infections were significantly associated with mean decreases of 0.10 in LAZ and 0.32 in LAD, and of 0.16 in LAZ and 0.48 in LAD, respectively. Cryptosporidium spp. infection was significantly associated with a mean decrease of 0.43 in WAVZ and 0.55 in LAVZ. The underestimated association between subclinical parasitic enteric infections and mild growth faltering in infants should be addressed in public health policies.

Interaction of zinc or vitamin A supplementation and specific parasite infections on Mexican infants' growth: a randomized clinical trial

BACKGROUND

The efficacy of micronutrient supplementation on growth may be modified by specific gastrointestinal parasite infections.

METHODS

We carried out a double-blind placebo-controlled trial to evaluate the effect of vitamin A and zinc supplementation on gastro-intestinal pathogen infections and growth among 584 infants in Mexico City. Children aged 5-15 months were assigned to receive either a vitamin A supplement every 2 months (20,000 IU of retinol for infants < or =; 1 year or 45,000 IU for infants >1 year), a daily supplement of 20 mg of zinc, a combined vitamin A-zinc supplement or a placebo, and were followed up for 1 year. Weight and length were measured once a month and morbidity histories were recorded twice a week for 12 months. Monthly stool samples were screened for Giardia duodenalis, Ascaris lumbricoides and Entamoeba spp. Growth velocity slopes, generated from the linear regression of individual child length, and height-for-age z-scores on time were analyzed as end points in regression models, adjusting for the presence of parasite infections.

RESULTS

The main effect of vitamin A supplementation was in height improvement (P<0.05), and was only found in the model evaluating infants with any parasite. There was an interaction effect of slower growth (P<0.05) found in infants infected with any parasite and supplemented with vitamin A in slower growth (P<0.05). In addition, the interaction of zinc supplementation and Giardia duodenalis or A. lumbricoides was associated with reduced growth (P<0.05).

CONCLUSION

Gastro-intestinal parasite infections may modify the effect that zinc or vitamin A supplementation has on childhood growth.

Maternal reports of child illness and the biochemical status of the child: the use of morbidity interviews in rural Bangladesh

In a longitudinal study of child growth and nutritional status in Bangladesh, child morbidity was recorded using health interviews with the mother. The aim of the present study was to establish whether maternal reports of child illness were associated with the biochemical health status of the child. Children aged 2–5 years (n 117) took part in the study and their mothers were interviewed every fortnight by Bangladeshi fieldworkers. Maternal reports of diarrhoea were associated with significantly lower plasma albumin concentrations (P < 0·001), poorer intestinal permeability (P < 0·001), higher plasma immunoglobulin A levels (P < 0·005) and higher α-1-antichymotrypsin (ACT) levels (P < 0·05) compared with children reported to be healthy. Children with fever had significantly higher ACT (P < 0·001) and lower albumin (P < 0·05) levels compared with their healthy counterparts. Respiratory infections (RI) were not associated with any significant changes; however, reports of RI with fever were associated with significantly higher levels of ACT than either illness individually (interaction P < 0·05). These highly significant associations between maternal reports of illness and biochemical profiles of child health support the use of health interviews in developing countries.

Iron supplementation increases small intestine permeability in primary schoolchildren in Lusaka, Zambia

Elevated intestinal permeability, measured as an increased lactulose:mannitol (L:M) ratio, indicates injury of the small intestinal mucosa. As part of a randomized iron and multi-micronutrient (without iron) supplementation trial (Nchito et al., 2004), we determined intestinal permeability in a subgroup of schoolchildren at 10 months' follow-up to assess the effect of the interventions. Among 153 children (mean age 10.2 years and 53.6% girls) iron supplementation resulted in a higher L:M ratio compared with placebo (0.29 vs. 0.21, P=0.025). There was no effect of multi-micronutrient supplementation, and no interaction between the interventions. The finding could be one of the mechanisms explaining the negative effects of medicinal iron supplementation on morbidity found in some other studies.

Anthelmintic treatment of rural Bangladeshi children: effect on host physiology, growth, and biochemical status

BACKGROUND

The effect of helminth infestation on the nutrition, growth, and physiology of the host is still poorly understood. Anthelmintic treatment of children in developing countries has had varying success in terms of growth improvements.

OBJECTIVE

The objective of this study was to assess the effect of regular deworming on child growth, physiology, and biochemical status.

DESIGN

The study was a 12-mo longitudinal intervention in 123 Bangladeshi children aged 2-5 y. Treatment (mebendazole) or placebo tablets were administered every 2 mo for 8 mo and again at 12 mo. Weight, height, midupper arm circumference, intestinal permeability, plasma albumin, alpha(1)-antichymotrypsin, and total protein concentration were assessed every 2 mo.

RESULTS

Treatment with mebendazole reduced the prevalence of Ascaris lumbricoides from 78% to 8%, of Trichuris trichiura from 65% to 9%, and of hookworm from 4% to 0%. There was no significant difference in the growth of treated children compared with those given placebo tablets. No changes in intestinal permeability or plasma albumin were observed after deworming. Significant decreases in total protein (P<0.001) and alpha(1)-antichymotrypsin (P<0.001) were observed in the treatment group, indicating possible reductions in inflammation and immunoglobulin concentration after deworming. A significant increase in the prevalence of Giardia intestinalis (from 4% to 49%) in the treatment group was associated with a short-term reduction in weight (P = 0.02) and higher intestinal permeability (P <0.001) in infected subjects. No long-term effects of G. intestinalis on growth were observed.

CONCLUSION

Low-intensity helminth infections, predominantly of A. lumbricoides and T. trichiura, do not contribute significantly to the poor growth and biochemical status of rural Bangladeshi children.

Comparison of intestinal function in human immunodeficiency virus-seropositive patients in Kampala and London

BACKGROUND

White homosexual men with human immunodeficiency virus (HIV) show progressive impairment of intestinal function assessed in terms of intestinal permeability and absorptive capacity. In this study we aimed to determine the effects of heterosexually acquired HIV on small-intestinal function in native Africans, among whom there is a high prevalence of tropical enteropathy.

METHODS

Intestinal absorptive capacity (using 3-O-methyl-D-glucose, D-xylose, and L-rhamnose) and permeability (differential 5-h urinary excretion of lactulose/L-rhamnose) were assessed in healthy white (n = 57) and black (n = 14) controls in London, apparently healthy black Africans in Kampala, Uganda (n = 26), HIV-infected patients with (n = 9) and without (n = 30) diarrhoea in Kampala, and 39 white homosexual men with HIV in London who were stratified to resemble the African patient group.

RESULTS

Intestinal integrity and absorptive capacity were significantly (P < 0.01) impaired in both black controls in London and apparently healthy black Africans, compared with white controls. HIV-infected white and black patients without diarrhoea did not differ significantly from white and black African controls, respectively, with the exception of increased intestinal permeability among the white patients. White and black African patients with HIV/acquired immunodeficiency syndrome (AIDS) and diarrhoea were found to have marked malabsorption and increased intestinal permeability. Although the relative increase in intestinal permeability was similar in the two groups, by far the largest values for intestinal permeability were found among black Africans with HIV/AIDS and diarrhoea.

CONCLUSIONS

Whites and blacks differ with regard to intestinal barrier function. HIV-positive black Africans without gastrointestinal symptoms differ insignificantly from white Londoners with homosexually acquired disease, whereas those with gastrointestinal symptoms have markedly abnormal indices of small-intestinal function with severely comprised intestinal integrity.

Relationships between soil-transmitted helminthiases and growth in urban slum schoolchildren in Ujung Pandang, Indonesia

This study examined the relationship between intestinal helminthiases and growth in urban slum schoolchildren. Children (n = 330) who received single doses of either pyrantel, albendazole, or placebo at baseline and again at 6 months were followed and examined fully at 0, 3, 6, and 12 months for helminth infections and anthropometry. Results of treatments indicated that all groups reduced their prevalence and intensity toward the period of the study. Reductions in intensity of both infections in the treatment groups were observed large in 3 and 12 months, whereas at 6 months reached mostly the initial level of infection. There was no significant difference in growth changes between the dewormed (once and twice) and the placebo groups. However, after controlling for some potential confounding factors, there was a significant relationship between reduction of A. lumbricoides infection and height gain at 3 and 12 months (both P < 0.05). In addition, there was a significant association between reduction in T. trichiura infection and increased midarm circumference at 3 and 12 months (P < 0.002 and P < 0.08, respectively). We conclude that treatment of helminth infections in school-age children may improve growth in areas where malnutrition and helminth infections are prevalent.

Improvements in appetite and growth in helminth-infected schoolboys three and seven weeks after a single dose of pyrantel pamoate

Appetite and growth were studied in primary schoolboys (6-10 years) infected with Ascaris lumbricoides (86%) and Trichuris trichiura (100%) who received a single dose of pyrantel pamoate (which has little or no effect on Trichuris trichiura) or a placebo. Boys were examined, allocated at random by descending Ascaris egg count to pyrantel (PR, n = 36) or placebo (PL, n = 36) groups, treated, and re-examined 3 and 7 weeks later. The 2 groups did not differ significantly before treatment in helminth infections, appetite, or growth. Three and 7 weeks after treatment, the PR group exhibited significantly greater increases than did the PL group in weight (0.2 kg and 0.4 kg more, respectively) and percentage weight-for-age (0.6% and 1.7% points more, respectively). Appetite increased significantly in the PR group at 3 and 7 weeks (P < 0.0005 and P < 0.01, respectively) but not in the PL group. The prevalence and intensity of A. lumbricoides infection were greatly reduced in the PR group at 3 and 7 weeks (both P < 0.0001) but not in the PL group. We conclude that treatment with pyrantel pamoate may improve appetite and growth in school children in areas where A. lumbricoides infections and poor growth are highly prevalent.

Effect of intestinal helminthiasis on intestinal permeability of early primary schoolchildren

Intestinal permeability of 246 early primary schoolchildren at 2 schools (106 of whom were infected with intestinal helminths) was assessed by using the lactulose/mannitol differential absorption test. The ratio of the urinary recoveries of lactulose and mannitol was determined after oral administration of a standard solution of the 2 sugars. Assessment of intestinal permeability was repeated on 100 infected children after treatment and on a cohort of 68 uninfected children. Infected and uninfected groups were compared with respect to baseline lactulose/mannitol ratio (L/M1) and change in lactulose/mannitol ratio between assessments (delta L/M). The correlations between baseline intensity of infection and L/M1, and between fall in intensity and delta L/M, were evaluated. Based on a crude index of socioeconomic status, each child was assigned to one of 3 socioeconomic groups; all but 3 children belonged to either groups 2 or 3. Trichuris trichiura and Ascaris lumbricoides were the 2 predominant infections; the hookworm infection rate was relatively low. The results suggested that helminthiasis exerted only a marginal effect on intestinal permeability, the impact of which in children from lower socioeconomic backgrounds was negligible in comparison with the cumulative effects of other factors.

Intestinal permeability: an overview

The noninvasive assessment of intestinal permeability in humans has a 20-year history. Because the tests are increasingly used in clinical practice and research and because there is much controversy, we reviewed the literature and outlined the potential and possible shortcomings of these procedures. Data was obtained from personal files and from a systemic search through MEDLINE and EMBASE. The principle of the differential urinary excretion of orally administered test markers is explained with reference to the desired physicochemical properties of the markers and how the principle can be exploited to allow assessment of various other gastrointestinal functions. The use of intestinal permeability tests for diagnostic screen for small bowel disease and assessment of responses to treatment, the pathogenesis of disease, normal intestinal physiology, and the effect of drugs and toxins on the intestine is described and reviewed. The controversy surrounding the anatomic location of the permeation pathways that the markers use is highlighted. Noninvasive tests of intestinal permeability have fulfilled early promises of usefulness in clinical practice and research. There is now a need for integrated research into the basic mechanisms of regulatory control of the intestinal barrier function.

Automated enzymatic assays for the determination of intestinal permeability probes in urine. 1. Lactulose and lactose

Lactulose is becoming the disaccharide of choice in the dual sugar assessment of passive permeability of the small intestinal mucosa. However its more widespread use is hampered by current analytical methods which are tedious and time consuming. An automated spectrophotometric technique for the assay of this sugar in urine is presented in which lactulose is linked by a series of enzyme reactions to the equimolar production of NADPH. In addition to lactulose, the procedure also gives accurate values for lactose, glucose and fructose in the urine sample. The assay has been shown to be highly specific for lactulose and lactose and was not affected by high concentrations of other sugars or other urinary constituents. Within assay and between assay precision were similar with the coefficient of variation for both sugars in the range 0.4-1.6%. The technique represents a significant improvement in time, simplicity and precision on existing methods of analysis.