Serious limitations of the current strategy to control Soil-Transmitted Helminths and added value of Ivermectin/Albendazole mass administration: A population-based observational study in Cameroon.

BACKGROUND: Soil-transmitted helminth (STH) infections remain a public health concern in sub-Saharan Africa. School-based mass drug administration (MDA) using the anthelminthic drug Mebendazole/Albendazole have succeeded in controlling morbidity associated to these diseases but failed to interrupt their transmission. In areas were filarial diseases are co-endemic, another anthelminthic drug (Ivermectin) is distributed to almost the entire population, following the community-directed treatment with ivermectin (CDTI) strategy. Since Ivermectin is a broad spectrum anthelmintic known to be effective against STH, we conducted cross-sectional surveys in two health districts with very contrasting histories of Ivermectin/Albendazole-based PC in order to investigate whether CDTI might have contributed in STH transmission interruption. METHODOLOGY: Cross-sectional surveys were conducted in two health districts with similar socio-environmental patterns but with very contrasting CDTI histories (Akonolinga health district where CDTI was yet to be implemented vs. Yabassi health district where CDTI has been ongoing for two decades). Stool samples were collected from all volunteers aged >2 years old and analyzed using the Kato-Katz technique. Infections by different STH species were compared between Akonolinga and Yabassi health districts to decipher the impact of Ivermectin/Albendazole-based MDA on STH transmission. PRINCIPAL FINDINGS: A total of 610 and 584 participants aged 2-90 years old were enrolled in Akonolinga and Yabassi health districts, respectively. Two STH species (Ascaris lumbricoides and Trichuris trichiura) were found, with prevalence significantly higher in Akonolinga health district (43.3%; 95% CI: 38.1-46.6) compared to Yabassi health district (2.5%; 95% CI: 1.1-5.1) (chi-square: 90.8; df: 1; p < 0.001). CONCLUSION/SIGNIFICANCE: These findings (i) suggest that Mebendazole- or Albendazole-based MDA alone distributed only to at-risk populations might not be enough to eliminate STH, (ii) support the collateral impact of Ivermectin/Albendazole MDA on A. lumbricoides and T. trichiura infections, and (iii) suggest that Ivermectin/Albendazole-based PC could accelerate STH transmission interruption.

Performance of the Kato-Katz method and real time polymerase chain reaction for the diagnosis of soil-transmitted helminthiasis in the framework of a randomised controlled trial: treatment efficacy and day-to-day variation.

BACKGROUND: Accurate, scalable and sensitive diagnostic tools are crucial in determining prevalence of soil-transmitted helminths (STH), assessing infection intensities and monitoring treatment efficacy. However, assessments on treatment efficacy comparing traditional microscopic to newly emerging molecular approaches such as quantitative Polymerase Chain Reaction (qPCR) are scarce and hampered partly by lack of an established diagnostic gold standard. METHODS: We compared the performance of the copromicroscopic Kato-Katz method to qPCR in the framework of a randomized controlled trial on Pemba Island, Tanzania, evaluating treatment efficacy based on cure rates of albendazole monotherapy versus ivermectin-albendazole against Trichuris trichiura and concomitant STH infections. Day-to-day variability of both diagnostic methods was assessed to elucidate reproducibility of test results by analysing two stool samples before and two stool samples after treatment of 160 T. trichiura Kato-Katz positive participants, partially co-infected with Ascaris lumbricoides and hookworm, per treatment arm (n = 320). As negative controls, two faecal samples of 180 Kato-Katz helminth negative participants were analysed. RESULTS: Fair to moderate correlation between microscopic egg count and DNA copy number for the different STH species was observed at baseline and follow-up. Results indicated higher sensitivity of qPCR for all three STH species across all time points; however, we found lower test result reproducibility compared to Kato-Katz. When assessed with two samples from consecutive days by qPCR, cure rates were significantly lower for T. trichiura (23.2 vs 46.8%), A. lumbricoides (75.3 vs 100%) and hookworm (52.4 vs 78.3%) in the ivermectin-albendazole treatment arm, when compared to Kato-Katz. CONCLUSIONS: qPCR diagnosis showed lower reproducibility of test results compared to Kato-Katz, hence multiple samples per participant should be analysed to achieve a reliable diagnosis of STH infection. Our study confirms that cure rates are overestimated using Kato-Katz alone. Our findings emphasize that standardized and accurate molecular diagnostic tools are urgently needed for future monitoring within STH control and/or elimination programmes.

The impact of four years of semiannual treatments with albendazole alone on lymphatic filariasis and soil-transmitted helminth infections: A community-based study in the Democratic Republic of the Congo.

BACKGROUND: The World Health Organization now recommends semiannual mass drug administration (MDA) of albendazole with integrated vector management as an option for eliminating lymphatic filariasis (LF) in areas of loiasis-endemic countries where it may not be safe to use diethylcarbamazine or ivermectin in MDA programs. However, the published evidence base to support this policy is thin, and uptake by national programs has been slow. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a community trial to assess the impact of semiannual MDA on lymphatic filariasis and soil-transmitted helminth infections (STH) in two villages in the Bandundu province of the Democratic Republic of the Congo with moderately high prevalences for LF and hookworm infections. MDA with albendazole was provided every six months from June 2014 to December 2017 with treatment coverages of the eligible population (all ≥ 2 year of age) that ranged between 56% and 88%. No adverse effects were reported during the trial. Evaluation at 48 months, (i.e. 6 months after the 8th round of MDA), showed that W. bancrofti microfilaremia (Mf) prevalence in the study communities had decreased between 2014 to 2018 from 12% to 0.9% (p<0.001). The prevalence of W. bancrofti antigenemia was also significantly reduced from 31.6% to 8.5% (p<0.001). MDA with albendazole also reduced hookworm, Ascaris lumbricoides and Trichuris trichiura infection prevalences in the community from 58.6% to 21.2% (p<0.001), from 14.0% to 1.6% and 4.1% to 2.9%, respectively. Hookworm and Ascaris infection intensities were reduced by 93% (p = 0.02) and 57% (p = 0.03), respectively. In contrast, Trichuris infection intensity was not significantly reduced by MDA (p = 0.61) over this time period. CONCLUSION/SIGNIFICANCE: These results provide strong evidence that semiannual MDA with albendazole alone is a safe and effective strategy for LF elimination in Central Africa. Community MDA also had a major impact on STH infections.

Paleoparasitology of Merovingian Corpses Buried in Stone Sarcophagi in the Saint-Martin-au-Val Church (Chartres, France).

Paleoparasitological analysis was carried on 4 Merovingian skeletons, dated from the late-5th to the late-9th centuries, and recovered in the church of Saint-Martin-au-Val in Chartres (Center region, France). The corpses were buried in stone sarcophagi, which were still sealed at the time of excavation. Parasite marker extraction was conducted on sediment samples taken from the abdominal and pelvic regions, but also on samples taken from under the head and the feet as control samples. Microscopic observation revealed the presence of 3 gastrointestinal parasites, namely the roundworm (Ascaris lumbricoides), the whipworm (Trichuris trichiura) and the fish tapeworm (genus Diphyllobothrium). This analysis contributes to a better knowledge of the health status and the lifestyle of ancient medieval populations during the Merovingian period, for which very few paleoparasitological data were available, up until now. It demonstrates the presence of the fish tapeworm for the first time during this period.

Prevalence and intensity of Ascaris lumbricoides infections in relation to undernutrition among children in a tea plantation community, Sri Lanka: a cross-sectional study.

BACKGROUND: Ascaris lumbricoides infections are one of the commonnest intestinal nematode infections in the world, with a profound negative effect on nutritional status among underprivileged populations. In Sri Lanka, Ascaris infections and low nutritional status still persist in the plantation sector. However, research regarding the association between Ascaris infections and nutritional status is scarce. The main purpose of this study was to determine the association between Ascaris infections and physical growth among children in a plantation sector in Sri Lanka. METHODS: A cross sectional study was conducted among 489 children aged between 1 and 12 years ina plantation sector, Sri Lanka, from January to April 2013. Anthropometric measurements were collected to assess height-for-age (HAZ), weight-for-age (WAZ) and weight-for-height (WHZ) to determine stunting, underweight and wasting respectively. Data on socio-demographic and antihelminthic treatment were ascertained using an interviewer administrated structured questionnaire. Stool samples were subjected to wet mount preparation followed byformaldehyde-ether sedimentation technique to diagnose Ascaris infection and a Kato Katz technique was performed to determine the eggs intensity. AnthroPlus, EpiInfo and SPSS software was used to analyze data. RESULTS: Of the study sample, 38.4% showed Ascaris lumbricoides infections. Light intensity infections (51%) were common in the infected children, followed by moderate (30%) and heavy (19%) infections. Prevalence of Ascaris infections was significantly associated with de-worming more than six months prior to the study. Prevalence of undernutrition among children was 61.7%. Forty-five per cent were underweight, while 24.1% and 21.5% of children were stunted and wasted respectively. However, no significant association was found between Ascaris infections status and undernutrition. Meanwhile, heavy intensity infections were associated with decreased values of WHZ (p = 0.020). CONCLUSIONS: Ascaris infections and undernutrition are still highly prevalent and a major public health problem in the plantation sector in Sri Lanka. Health and nutrition intervention programs should be implemented to increase the nutritional status of children.

Schistosoma haematobium and soil-transmitted Helminths in Tana Delta District of Kenya: infection and morbidity patterns in primary schoolchildren from two isolated villages.

BACKGROUND: Schistosomes and soil-transmitted helminths (STH) (hookworm, Trichuris trichiura and Ascaris lumbricoides) are widely distributed in developing countries where they infect over 230 million and 1.5 billion people, respectively. The parasites are frequently co-endemic and many individuals are co-infected with two or more of the species, but information on how the parasites interact in co-infected individuals is scarce. The present study assessed Schistosoma haematobium and STH infection and morbidity patterns among school children in a hyper-endemic focus in the Tana River delta of coastal Kenya. METHODS: Two hundred and sixty-two children aged 5-12 years from two primary schools were enrolled in the study. For each child, urine was examined for S. haematobium eggs and haematuria, stool was examined for STH eggs, peripheral blood was examined for eosinophilia and haemoglobin level, the urinary tract was ultrasound-examined for S. haematobium-related pathology, and the height and weight was measured and used to calculate the body mass index (BMI). RESULTS: Prevalences of S. haematobium, hookworm, T. trichiura and A. lumbricoides infection were 94, 81, 88 and 46 %, respectively. There was no significant association between S. haematobium and STH infection but intensity of hookworm infection significantly increased with that of T. trichiura. Lower BMI scores were associated with high intensity of S. haematobium (difference =-0.48, p > 0.05) and A. lumbricoides (difference =-0.67, p < 0.05). Haematuria (both macro and micro) was common and associated with S. haematobium infection, while anaemia was associated with high intensity of S. haematobium (OR = 2.08, p < 0.05) and high hookworm infections OR = 4.75; p < 0.001). The majority of children had eosinophilia, which was significantly associated with high intensity of hookworm infection (OR = 5.34, p < 0.05). Overall 38 % of the children had ultrasound-detectable urinary tract morbidity, which was associated with high intensity of S. haematobium infection (OR = 3.13, p < 0.05). CONCLUSION: Prevalences of S. haematobium and STH infections among the primary school children were high and the parasites were responsible for significant morbidity. A clear synergistic interaction was observed between hookworm and T. trichiura infections. Increased coverage in administration of praziquantel and albendazole in the area is recommended to control morbidity due to these infections.

The impact of two semiannual treatments with albendazole alone on lymphatic filariasis and soil-transmitted helminth infections: a community-based study in the Republic of Congo.

Implementation of mass drug administration (MDA) with ivermectin plus albendazole (ALB) for lymphatic filariasis (LF) has been delayed in central Africa because of the risk of serious adverse events in subjects with high Loa loa microfilaremia. We conducted a community trial to assess the impact of semiannual MDA with ALB (400 mg) alone on LF and soil-transmitted helminth (STH) infections in the Republic of Congo. Evaluation at 12 months showed that ALB MDA had not significantly reduced Wuchereria bancrofti antigenemia or microfilaria (mf) rates in the community (from 17.3% to 16.6% and from 5.3% to 4.2%, respectively). However, the geometric mean mf count in mf-positive subjects was reduced from 202.2 to 80.9 mf/mL (60% reduction, P = 0.01). The effect of ALB was impressive in 38 subjects who were mf-positive at baseline and retested at 12 months: 37% had total mf clearance, and individual mf densities were reduced by 73.0%. MDA also dramatically reduced the hookworm infection rate in the community from 6.5% to 0.6% (91% reduction), with less impressive effects on Ascaris and Trichuris. These preliminary results suggest that semiannual community MDA with ALB is a promising strategy for controlling LF and STH in areas with coendemic loiasis.

Incidental detection of ascariasis worms on USG in a protein energy malnourished (PEM) child with abdominal pain.

A 10-year-old child presented with dull aching periumbilical abdominal pain for 15 days. The child was not gaining weight despite a good appetite. Physical examination of the child revealed grade-I protein energy malnourishment (PEM) according to IAP (Indian Academic of Paediatrics) classification. The rest of the systemic examination was normal. Routine blood investigation revealed anaemia with eosinophilia. Abdominal ultrasonography did not show any abnormality with curvilinear transducer (3.5-5 MHz), however, linear ultrasound transducer (7.5-12 MHz) with harmonic tissue imaging showed worms in the lumen of the small intestine with curling movement on real time scanning. Stool examination for the eggs of ascariasis was positive. The patient was treated with antihelminthic drugs. Dietary modification for the PEM was advised. After 3 months of treatment, the patient improved and stool examination for Ascaris was negative on follow-up.

Soil-transmitted helminths in southern highland Rwanda: associated factors and effectiveness of school-based preventive chemotherapy.

OBJECTIVES: Preventive chemotherapy of schoolchildren against soil-transmitted helminths (STHs) is widely implemented in Rwanda. However, data on its actual efficacy are lacking. We assessed prevalence, associated factors and manifestation of STH infection among schoolchildren in southern highland Rwanda as well as cure and reinfection rates. METHODS: Six hundred and twenty-two children (rural, 301; urban, 321) were included preceding the administration of a single dose of 500 mg mebendazole. Before treatment, and after 2 and 15 weeks, STH infection was determined by Kato-Katz smears and by PCR assays for Ascaris lumbricoides. Clinical and anthropometric data, socio-economic status and factors potentially associated with STH infection were assessed. RESULTS: Soil-transmitted helminth (STH) infection was present in 38% of rural and in 13% of urban schoolchildren. Ascaris lumbricoides accounted for 96% of infections. Of these, one-third was detected by PCR exclusively. Factors associated with STH infection differed greatly between rural and urban children. Likewise, STH infection was associated with stunting and anaemia only among urban children. The cure rate after 2 weeks was 92%. Among eight non-cleared A. lumbricoides infections, seven were submicroscopic. Reinfection within 3 months occurred in 7%, but the rate was higher among rural children, and with initially present infection, particularly at comparatively high intensity. CONCLUSIONS: The rural-urban difference in factors associated with STH infection and in reinfection rates highlights the need for targeted interventions to reduce transmission. PCR assays may help in detecting low-level infections persisting after treatment. In southern Rwanda, mebendazole is highly effective against the STH infections predominated by A. lumbricoides.

The acceptability and safety of praziquantel alone and in combination with mebendazole in the treatment of Schistosoma mansoni and soil-transmitted helminthiasis in children aged 1-4 years in Uganda.

OBJECTIVE: There is limited information on the acceptability and safety of praziquantel for treatment of schistosomiasis in children below the age of four years. In addition, although mebendazole has been extensively used together with praziquantel against infections with schistosomiasis and soil-transmitted helminthiasis (STH) in school-aged children, no specific acceptability or safety studies have been published on this drug combination in younger children. METHODS: A randomized clinical trial was conducted to determine the safety of praziquantel alone and in combination with mebendazole in the treatment of Schistosoma mansoni and STH in children aged 1 to 4 years. RESULTS: A total of 596 children from Bwondha fishing community in Mayuge district and Wang-Kado fishing community in Nebbi district were investigated using duplicate Kato-Katz thick smears of two stool samples and 130 (21·8%) were found infected with S. mansoni. Of these, 19·2% (25) had heavy intensity of infections. Of the infected children, 82 were included and randomised into praziquantel (40 mg/kg) + mebendazole (500 mg) or praziquantel (40 mg/kg) alone. CONCLUSION: Many symptoms were reported before treatment while very few were reported after treatment and all on treatment day. No serious adverse events were reported or observed after treatment. Praziquantel with or without mebendazole was well tolerated in small children in the study area.

Impact of community-directed treatment on soil transmitted helminth infections in children aged 12 to 59 months in Mazabuka District, Zambia.

This study assessed the impact of adding community-directed treatment (ComDT) to the routine health facility (HF)-based treatment on prevalence and intensity of soil transmitted helminth (STH) infections among children aged 12 to 59 months. Repeated cross-sectional surveys were conducted among randomly selected children of this age group from the intervention area (HF+ComDT area) and the comparison area (HF area) at baseline (n=986), 12 months (n=796) and 18 months (n=788) follow-up. The prevalence of Ascaris lumbricoides was significantly higher in the HF+ComDT as compared to the HF area at baseline (P=0·048), but not at 12 and 18 months follow-up. At baseline the HF+ComDT area had significantly higher intensities of A. lumbricoides compared to the HF area (P<0·001), but not at 12 and 18 months follow-ups. Prevalence and intensity of hookworm did not differ significantly between treatment arms at any time. Analysis of trends showed a significant decrease in prevalence of A. lumbricoides and hookworm in the HF+ComDT area (P<0·001), of hookworm in the HF area (P<0·05), but not of A. lumbricoides in the HF area. It is concluded that the ComDT approach generally enhanced the treatment effect among under-five year children and that this alternative approach may also have advantages in other geographical settings.

[Case report: an intestinal obstruction due to ascariasis]. / Olgu Sunumu: Ascariasise Bagli Intestinal Obstrüksiyon.

Ascaris lumbricoides (A. lumbricoides) with which one billion people around the world is infected is also widely seen in Turkey. This case report presents an ascariasis infection which displayed typical radiological findings in Kocaeli, a non-endemic region of Turkey. The patient was admitted to hospital with symptoms of heavy abdominal pain, nausea-vomiting and weakness. The symptoms had started weakly three weeks earlier and the patient had applied to a private health care center. After a through examination with several appropriate tests including a barium small-bowel enema, a morphological finding similar to helminth was observed filling the lumen of the jejunum. When rectal swabs were examined A. lumbricoides oocytes were discovered. The patient was treated for two days with nasogastric drainage, piperazine (3.5 gr/day) in addition to a supportive therapy. The patient was surgically diagnosed to have a jejunal obstruction due to ascariasis.

The effect of iron and multi-micronutrient supplementation on Ascaris lumbricoides reinfection among Zambian schoolchildren.

A randomised, placebo-controlled, double-blind trial was conducted among schoolchildren in Chawama, Lusaka, Zambia, to determine the effect of iron and multi-micronutrients on reinfection with Ascaris lumbricoides. Supplementation was given on every school day for 10 months. Baseline A. lumbricoides prevalence and geometric mean intensity among positives were 43.4% and 2526 eggs per gram (epg) faeces, respectively. Serum ferritin <12microg/l was associated with higher egg counts than serum ferritin >or=12microg/l (4728 vs. 2036epg, P=0.033). Of 406 children recruited, 378 (93.1%) were examined at baseline and all infected children were treated and cure ascertained. The mean number of tablets taken per week was 2.5, giving 50% compliance. At six months 283 (74.9%) children complied, and reinfection intensities in those receiving iron were lower than in those receiving placebo (1600 vs. 3085epg, P=0.056). This effect disappeared at 10 months, where 215 (56.9%) complied. Iron had no effect on A. lumbricoides reinfection rates and multi-micronutrients had no effect on reinfection rates or intensities. Iron appears to affect reinfection intensity with A. lumbricoides, but further investigations are required to confirm this effect and elucidate the mechanisms involved.

Effectiveness of dried Carica papaya seeds against human intestinal parasitosis: a pilot study.

The tropical fruit Carica papaya and its seeds have proven antihelminthic and anti-amoebic activities. To determine the effectiveness of air-dried C. papaya seeds on human intestinal parasitosis, 60 asymptomatic Nigerian children with stool microscopic evidence of intestinal parasites received immediate doses (20 mL) of either an elixir composed with air-dried C. papaya seeds and honey (CPH) or honey alone (placebo) in two randomized treatment groups. Repeat stool microscopic examinations were conducted 7 days postintervention for intestinal parasites. Significantly more subjects given CPH elixir than those given honey had their stools cleared of parasites [23 of 30 (76.7%) vs. five of 30 (16.7%); z = 4.40, P = .0000109]. There were no harmful effects. The stool clearance rate for the various types of parasites encountered was between 71.4% and 100% following CPH elixir treatment compared with 0-15.4% with honey. Thus, air-dried C. papaya seeds are efficacious in treating human intestinal parasites and without significant side effects. Their consumption offers a cheap, natural, harmless, readily available monotherapy and preventive strategy against intestinal parasitosis, especially in tropical communities. Further and large-scale intervention studies to compare C. papaya with standard antiparasitic preparation are desirous.

The use of NaFeEDTA-fortified fish sauce is an effective tool for controlling iron deficiency in women of childbearing age in rural Vietnam.

One cost-effective strategy for controlling iron deficiency is the fortification of staple foods or condiments with iron. We evaluated the effectiveness of fortifying fish sauce with NaFeEDTA for improving iron status in women of childbearing age in Vietnam in a double-blind intervention with randomization by village. All families in the selected villages were supplied with fish sauce that was either unfortified (Group C, 10 villages) or fortified with NaFeEDTA [9 mmol (500 mg) Fe/L, Group F, 11 villages] for 18 mo. The effect of fortification was assessed in the 576 women (n = 288/group) by measuring hemoglobin and serum ferritin (SF) at 6, 12, and 18 mo. Analysis of the group x time interaction using a repeated-measures test for each response demonstrated a significant effect of fortification on hemoglobin (P = 0.039) and log SF (P < 0.0001) in Group F with no significant changes in Group C. The prevalence of iron deficiency (SF < 12 microg/L) decreased from 22.3 to 4.0% and the prevalence of anemia (hemoglobin < 120 g/L) from 24.7 to 8.5% in Group F with no significant changes in Group C. NaFeEDTA fortification of fish sauce is an effective method for reducing the prevalence of iron deficiency in women in Vietnam.

Increase in serum beta-carotene following dark green leafy vegetable supplementation in Mebendazole-treated school children in Bangladesh.

OBJECTIVE: To study the effect of consumption of dark green leafy vegetables (DGLV) and sweet pumpkin on serum beta-carotene and retinol concentrations in children treated for Ascaris lumbricoides. DESIGN: Experimental study with a randomised design. SUBJECTS: A total of 110 primary school children aged 8-12 y in northwestern Bangladesh. INTERVENTIONS: All children were de-wormed and 2 weeks later randomly assigned to one of three groups to receive for 6 days per week, for 6 weeks, one complete meal containing either: (1) 4.4 mg beta-carotene from DGLV (n=37, after 18 dropouts); (2) 1.5 mg beta-carotene from sweet pumpkin (n=36, 18 dropouts); or (3) vegetables containing virtually no beta-carotene (control) (n = 37, 18 dropouts). RESULTS: Significant increases (P < 0.001) in mean serum beta-carotene concentrations were seen in all three study groups, with a statistically higher increase (micromol/l) in the DGLV group (0.44; 95% confidence interval (CI) 0.32, 0.55) compared to the control group (0.20; 95% CI 0.14, 0.26; P = 0.002). The increase in serum retinol (micromol/l) was statistically significant (P=0.04) only in the DGLV group (mean 0.066; 95% CI 0.002, 0.13), but this increase was not different from the increase in the control group. CONCLUSION: In children successfully treated for Ascaris lumbricoides, a substantial increase in serum beta-carotene was seen after feeding with a moderately high cumulative dose of DGLV for 6 weeks.

Vitamin A status of Indonesian children infected with Ascaris lumbricoides after dosing with vitamin A supplements and albendazole.

In developing countries, both marginal vitamin A status and intestinal helminths are common among children. Indonesian children (n = 309, 0.6-6.6 y), known to be infected with Ascaris lumbricoides, were randomized into six different treatment groups (A-F). The treatments included 210 mumol vitamin A supplement and a dose of 400 mg albendazole (5-propylthio-1H-benzimidazol-2-yl carbamic acid methyl ester) administered orally either at the same health visit (Groups B and F) or at different contact times during a 1-mo period (groups A, C, D and E). Vitamin A status was assessed both before and 3-4 wk after the treatments by the modified relative dose response (MRDR) test. Vitamin A supplementation was most important in improving the vitamin A status (P < 0.0001) of these children, whereas treatment for ascariasis alone (P = 0.370) and the statistical interaction between treatment for ascariasis and vitamin A (P = 0.752) were not. Serum retinol concentrations marginally improved (P = 0.051) in two of the groups that received vitamin A and albendazole but not in the third group that received vitamin A only. The MRDR test proved a better discriminator of the effects of these treatments on vitamin A status than changes in serum retinol concentrations.