Hand hygiene intervention to optimize helminth infection control: Design and baseline results of Mikono Safi-An ongoing school-based cluster-randomised controlled trial in NW Tanzania.

INTRODUCTION: Soil transmitted helminths (STH) can affect over 50% of children in some parts of Tanzania. Control measures involve annual deworming campaigns in schools, but re-infection is rapid. This paper presents the design and baseline survey results of an ongoing school-based cluster-randomised controlled trial in Kagera region, NW Tanzania. The trial aims to determine whether the effect of routine deworming on the prevalence of Ascaris lumbricoides and Trichuris trichiura infections among school aged children can be sustained when combined with a behaviour change intervention promoting handwashing with water and soap. METHODS: As part of the trial, a total of 16 schools were randomised to receive the intervention (N = 8) or as controls (N = 8). Randomisation was stratified per district and restricted to ensure pre-trial STH prevalence was balanced between study arms. The combination intervention to be tested comprises class-room based teacher-led health education, improvement of handwash stations, coloured nudges to facilitate handwashing and parental engagement sessions. The impact evaluation involves two cross-sectional surveys conducted at baseline and endline. The objectives of the baseline survey were: (i) to confirm whether the deworming campaign was successful, and identify and treat students still infected about 2 weeks after deworming, (ii) to document any baseline differences in STH prevalence between trial arms, and (iii) to assess handwashing behaviours, and access to water and sanitation at school and home. We randomly sampled 35 students per class in Grades 1-6 (an average of 200 children per school), stratified to ensure equal representation between genders. Assenting students were interviewed using a structured questionnaire and asked to provide a stool specimen. RESULTS: Results of the baseline survey conducted about 2 weeks after deworming shows balanced demographic and STH prevalence data across trial arms. We observed a low prevalence of ascariasis (< 5%) as expected; however, the prevalence of trichuriasis was still about 35% in both arms. CONCLUSION: The randomisation procedure was successful in achieving a balanced distribution of demographic characteristics and helminth infections between trial arms. The intervention is being rolled out. The current deworming treatment regimen may need to be revised with regards to the treatment of trichuriasis.

Development of a Droplet Digital PCR for Detection of Trichuriasis in Sheep.

Trichuriasis is a serious threat to the economic development of animal husbandry. This research aimed to establish a droplet digital PCR (ddPCR) method to detect Trichuris spp. for the early diagnosis and prevention of trichuriasis in sheep. The real-time quantitative PCR (qPCR) and ddPCR methods were used for the detection of nematodes by targeted amplification of the ITS gene. Each means was evaluated to optimize the limit of detection and reproducibility. For a recombinant plasmid, the qPCR results showed that the detection limit was 31.7 copies per reaction. In contrast to qPCR, ddPCR was able to detect concentrations below 3.17 copies per reaction. Both assays exhibited good reproducibility. However, the ddPCR method was more stable for low-copy-number detection. This new assay was specific for Trichuris spp. and did not cross-react with other relevant gastrointestinal nematodes. A total of 98 clinical samples were tested with both assays. The results showed that the positive rate of ddPCR (80.6%) was higher than that of qPCR (72.4%). This method could be used as an efficient molecular biology tool to test for Trichuris spp. and could be a new valuable tool for the clinical diagnosis and prevention of trichuriasis.

Assessment of schistosomiasis and soil-transmitted helminths prevalence in school-aged children and opportunities for integration of control in local health services in Kwilu Province, the Democratic Republic of the Congo.

OBJECTIVE: To determine the prevalence of schistosomiasis (SCH) and soil-transmitted helminths (STH) in the Democratic Republic of Congo, and to assess the capacity of the local health centres for diagnosis and treatment. METHODS: Cross-sectional school-based survey in two health districts in the Province of Kwilu. We collected a stool and a urine sample for parasitological examination. Urine filtration and duplicate Kato-Katz thick smears were used for the diagnosis of SCH. Health centres were evaluated using a structured questionnaire. RESULTS: In total, 526 children participated in the study and the overall prevalence of Schistosoma mansoni infection was 8.9% (95% CI: 3.5-13.2) in both districts. The prevalence was higher in Mosango (11.7%; 95% CI: 8.9-14.8) than Yasa Bonga district (6.2%; 95% CI: 1.1-11.4). Urine filtration showed that Schistosoma haematobium infection was not present. The combined STH infection prevalence was 58.1% in both districts; hookworm infection was the most common STH found in 52.9% (95% CI: 29.3-62.4) of subjects, followed by Ascaris lumbricoides 9.3% (95% CI: 5.8-15.5) and Trichuris trichiura 2.1% (95% CI: 0.9-4.9). Mixed STH infections were observed as well as SCH-STH coinfection. CONCLUSION: Further mapping of both SCH and STH burden is needed, and coverage of preventive chemotherapy in school-aged children should be increased.

Worm Infections in Children.

• On the basis of research evidence, worm infections are important global child health conditions causing chronic disability that lasts from childhood into adulthood (Table 1). (2)(3) Evidence Quality: B • On the basis of research evidence, the major worm infections found in developing countries include ascariasis, trichuriasis, hookworm infection, and schistosomiasis; toxocariasis, enterobiasis, and cysticercosis are also found in poor regions of North America and Europe. (4)(9)(13) Evidence Quality: B • On the basis of expert consensus, children and adolescents are often vulnerable to acquiring large numbers of worms, ie, high-intensity infections (Fig 1)(21)(22)(23) Evidence Quality: D • On the basis of expert consensus and research evidence, moderate and heavy worm burdens cause increased morbidity because of growth and intellectual stunting in children and adolescents. Many of these effects may result from helminth-induced malnutrition. (21)(22)(23) Evidence Quality: C • On the basis of expert consensus and research evidence, worm infections are also commonly associated with eosinophilia. (48) (49) Evidence Quality: B • On the basis of research evidence as well as consensus, helminthes can cause inflammation in the lung (asthma), gastrointestinal tract (enteritis and colitis), liver (hepatitis and fibrosis), and urogenital tract. (7)(21)(22)(23)(27)(28)(40)(41)(43) Evidence Quality: B • On the basis of research evidence, microscopy techniques for diagnosis of worm infections in children often exhibit suboptimal sensitivities and specificities, necessitating new or improved diagnostic modalities such as polymerase chain reaction. (54)(55) Evidence Quality: A • On the basis of research evidence and expert consensus, mass drug administration ("preventive chemotherapy") has becomea standard practice for ministries of health in low- and middle-income countries to control intestinal helminth infections and schistosomiasis. (67)(68) Evidence Quality: B.

Field validity and feasibility of four techniques for the detection of Trichuris in simians: a model for monitoring drug efficacy in public health?

BACKGROUND: Soil-transmitted helminths, such as Trichuris trichiura, are of major concern in public health. Current efforts to control these helminth infections involve periodic mass treatment in endemic areas. Since these large-scale interventions are likely to intensify, monitoring the drug efficacy will become indispensible. However, studies comparing detection techniques based on sensitivity, fecal egg counts (FEC), feasibility for mass diagnosis and drug efficacy estimates are scarce. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, the ether-based concentration, the Parasep Solvent Free (SF), the McMaster and the FLOTAC techniques were compared based on both validity and feasibility for the detection of Trichuris eggs in 100 fecal samples of nonhuman primates. In addition, the drug efficacy estimates of quantitative techniques was examined using a statistical simulation. Trichuris eggs were found in 47% of the samples. FLOTAC was the most sensitive technique (100%), followed by the Parasep SF (83.0% [95% confidence interval (CI): 82.4-83.6%]) and the ether-based concentration technique (76.6% [95% CI: 75.8-77.3%]). McMaster was the least sensitive (61.7% [95% CI: 60.7-62.6%]) and failed to detect low FEC. The quantitative comparison revealed a positive correlation between the four techniques (Rs = 0.85-0.93; p<0.0001). However, the ether-based concentration technique and the Parasep SF detected significantly fewer eggs than both the McMaster and the FLOTAC (p<0.0083). Overall, the McMaster was the most feasible technique (3.9 min/sample for preparing, reading and cleaning of the apparatus), followed by the ether-based concentration technique (7.7 min/sample) and the FLOTAC (9.8 min/sample). Parasep SF was the least feasible (17.7 min/sample). The simulation revealed that the sensitivity is less important for monitoring drug efficacy and that both FLOTAC and McMaster were reliable estimators. CONCLUSIONS/SIGNIFICANCE: The results of this study demonstrated that McMaster is a promising technique when making use of FEC to monitor drug efficacy in Trichuris.

Using national health weeks to deliver deworming to children: lessons from Mexico.

Mexico established national health weeks (NHWs) in the early 1980s to promote childhood vaccinations. Because of the cumulative worldwide peer-reviewed scientific evidence, the recommendations of the World Health Organization and other international organisations, the political will of the Mexican government and the infrastructure provided by the NHWs, deworming was added to the NHWs in 1993. In addition to the Ministry of Health, several other government organisations participated in administering the deworming component. Tens of millions of school-age and preschool children between the ages of 2 years and 14 years now receive deworming (a single 400 mg dose of albendazole) approximately every 8 months. Between 1993 and 1998 evaluations were carried out in over 90,000 children to determine the effect of NHWs on the prevalence of geohelminth infections. In 1993, the overall prevalence of Ascaris was 20% and that of Trichuris was 15%. Prevalences decreased significantly over time (p <0.001). Treatment efficacy for Ascaris ranged from 91.6% to 85.3%, and for Trichuris, from 97.9% to 42.6%. In 1998, after conducting 12 NHWs with deworming, the respective prevalences were Ascaris 8% and Trichuris 11%. The experience of Mexico in integrating albendazole into its NHWs shows how deworming can be delivered to large numbers of at-risk children using an existing infrastructure. The NHW approach may be generalisable in other countries with successful national vaccination campaigns. The challenge remaining is to sustain the deworming programme until other longer-term behavioural, environmental and socioeconomic changes can be implemented.

Assessment of combined ivermectin and albendazole for treatment of intestinal helminth and Wuchereria bancrofti infections in Haitian schoolchildren.

This randomized, placebo-controlled trial investigated the efficacy and nutritional benefit of combining chemotherapeutic treatment for intestinal helminths (albendazole) and lymphatic filariasis (ivermectin). Children were infected with Ascaris (29.2%), Trichuris (42.2%), and hookworm (6.9%), with 54.7% of children having one or more of these parasites. Wuchereria bancrofti microfilaria were found in 13.3% of the children. Children were randomly assigned to treatment with placebo, albendazole, ivermectin, or combined therapy. Combination treatment reduced the prevalence of Trichuris infections significantly more than either drug alone. Combination therapy also significantly reduced the prevalence and density of W. bancrofti microfilaremia compared with placebo or ivermectin alone. Only combination therapy resulted in significantly greater gains in height (hookworm-infected children) or weight (Trichuris-infected children) compared with the placebo group. Combined albendazole and ivermectin was a more efficacious treatment for intestinal helminth and W. bancrofti infections in children and resulted in nutritional benefits not found with either drug alone.

A study of the cost effectiveness of selective health interventions for the control of intestinal parasites in rural Bangladesh.

The study examined the cost effectiveness of 4 different regimens in reducing the prevalence and intensity of infection of Ascaris lumbricoides, Trichuris trichiura, and hookworm over an 18-mo period in randomized community samples of children aged 2-8 yr living in rural Bangladesh. The household was the unit of randomization in each community. The 4 regimens were (1) only chemotherapy to all household members at the commencement of the study (i.e., at an interval of 18 mo), (2) same as group (1) and regular health education throughout the study period, (3) chemotherapy to all household members at the commencement of the study and subsequent chemotherapy to all children at intervals of 6 mo, and (4) same as group 3 with the addition of regular health education throughout the study period. Health education (through home and school visits and focus group discussions) was aimed at increasing awareness of worm transmission and the disabilities caused by intestinal helminths. Simple ways of improving personal hygiene and sanitation through hand washing, nail trimming, wearing of shoes, and use of a latrine and clean water supplies were encouraged. Because albendazole is a broad spectrum anthelmintic, the cost effectiveness of the 4 interventions were compared by the weighted percentage reduction in prevalence and the weighted percentage reduction in intensities of infection as measured by geometric mean egg loads of all 3 worms combined. The most cost-effective strategy was the single albendazole mass chemotherapy at an interval of 18 mo. The 2 regimens involving health education were the least cost effective.

Helminth parasites, a major factor in malnutrition.

The author discusses the significance of helminth and schistosome infections in exacerbating nutritional problems in many countries, and advocates population-wide treatment where there is clear evidence that this would yield substantial gains in the quality of life.

PIP: Helminth and schistosome infections occur in the same geographical areas as does malnutrition. These parasitic infections can occur already in malnourished persons. Hookworm infections reduces food intake and/or increase nutrient wastage via vomiting, diarrhea, or blood loss. These effects exasperate protein energy malnutrition, anemia, and other nutrient deficiencies. Hookworm infection reduces the work capacity and productivity of children and adults; increases maternal and fetal morbidity, premature delivery, and low birth weight, as well as the susceptibility to other infections; and reduces the rate of cognitive development. These social and economic consequences in turn reduce the ability of people and families to raise crops or earn enough money to buy food and other essentials. As many as 90% of the children in some areas of the developed world are infected with roundworm. More than 100,000 deaths in 1987 resulted from complications of roundworm infection (e.g., intestinal obstruction). Roundworm infection reduces the body's ability to use protein and to absorb fat, which worsens protein energy malnutrition. Other nutrient effects of roundworm infection are exacerbation of vitamin A deficiency and lactose and milk intolerance. Whipworm infection can effect prolapse of the rectum and nutritional problems. Treatment of children with whipworm improves hematocrit, growth rates and anthropometry, and serum albumin, and reduces diarrhea and bacterial and protozoan infections in the bowel. Schistosomiasis causes nutritional effects similar to those of helminths. Studies in Kenya show that, in children, 1 treatment against worm, infections improves growth and fitness within 4 months. Other studies in Kenya show that treating children for worms or anemia improves weight gains per month at least as much as and usually more than school feeding programs, a more labor intensive, complicated, and expensive effort. Deworming programs should operate in areas where undernutrition exceeds 25% and worms are prevalent.

Assessment of the effectiveness of primary health care interventions in the control of three intestinal nematode infections in rural communities.

In a 30 months' longitudinal study, primary health care intervention was effective in reducing the prevalence of three common intestinal nematode infections (Ascaris lumbricoides, Trichuris trichiura and Necator americanus) in three communities. This was achieved by training school leavers and auxiliary aides as microscopists, health inspectors and field assistants and deploying them to provide screening, surveillance, environmental sanitation, and mass-expulsion chemotherapy (MEC). Post-control surveillance confirmed that the prevalence of these infections had been greatly reduced. The prevalence of Ascaris lumbricoides had declined from 49.3% (pre-intervention) to 10.5% (post-intervention). Hookworm had fallen from 31.4% (pre-intervention) to 4.1% (post-intervention) and whipworm from 40.7% (pre-intervention) to 6.5% (post-intervention). Overall percentage decreases of 78.7%, 86.9% and 84.0% were recorded for Ascaris lumbricoides, Necator americanus and Trichuris trichiura respectively. The initial decline in prevalence was due to the MEC campaign, but the improved sanitation and health education presumably reduced the reinfection rate. If the entire population participated, periodic repetition of the mass expulsion therapy campaign at appropriate intervals combined with continued attention to environmental hygiene and prolonged health education could bring these infections under control within a few years.

PIP: In the late 1980s and early 1990s in Nigeria, parasitologist evaluated the effectiveness of health education, environmental sanitation, and mass expulsion chemotherapy (MEC) in controlling endemic parasitic infections (Ascaris lumbricoides, Trichuris trichiura, and Necator americanus) in the population served by health care centers in Ndele, Emohua, and Aluu (in the eastern area of the Niger Delta Basin). 240 dropouts from primary and secondary schools and 45 auxiliary nurses from the communities underwent 6 months, training to become health inspectors, microscopists, field assistants, and surveillance staff. About 120 people/day frequented each community health education forum at the centers. The communities worked together to build ventilation-improved pit latrines, resulting in a considerable decline of open air defecation. 54.5% of the population provided stool samples so researchers could determine the prevalence of intestinal nematode infections. Health workers administered a single dose of either Alcopar or Zentel to all people diagnosed with nematode infection. The infected people also received nutritional supplements as required. Initial prevalence was 49.3% for A. lumbricoides, 40.7% for T. trichiura, and 31.4% g for N. americanus. The interventions contributed to a decline in overall prevalence ranging from 70.6% (A. lumbricoides in Ndele) to 88.2% (N. americanus in Emohua). The percentage of reduction of A. lumbricoides infection increased as age increased (e.g., 73.5% reduction for 5 year old children and 86% reduction for 45 to 54 year olds). Little difference in reduction with age existed for N. americanus and T. trichiura infections, however, 30 months after intervention prevalence was 10.5% for A. lumbricoides, 6.3% for T. trichiura, and 3.9% for N. americanus. These findings indicated that health education campaigns, MEC campaigns, and improvement in environmental sanitation result in considerable reduction of nematode infections.