Mass Deworming Research Articles

Deworming and adjuvant interventions for improving the developmental health and well‐being of children in low‐ and middle‐income countries: a systematic review and network meta‐analysis

Deworming and adjuvant interventions for improving the developmental health and well‐being of children in low‐ and middle‐income countries: a systematic review and network meta‐analysis

Malaria and soil-transmitted helminthes coinfection in a rural community of Kwara State, North Central Nigeria

Malaria and soil-transmitted helminthes (STH) are common in most developing countries especially Nigeria. The aim of this study was to assess the rate of occurrence of Plasmodium falciparum and STHs coinfection and to determine the associated risk factors. A community based study was conducted on 300 individuals living in Oke-Oyi a rural community in Kwara State, North Central Nigeria, between January and June 2014. Blood samples were collected by finger prick to determine malaria parasitaemia using thick and thin film method while stool samples were processed using formalin-ether sedimentation technique and examined microscopically for intestinal parasites. Well structured questionnaire was administered to ascertain socio-economic characteristics of the subjects. The prevalence of malaria was 56.7% while the prevalence of STHs/malaria coinfection was 40.1%. The age group 1-10 was found to be the most infected (74.3%) while males (60.7%) were more infected than females (51.8%). Ascaris lumbricoides Linnaeus, 1758 was the most prevalent (60.5%) STHs infection followed by Trichuris trichiura (Linnaeus, 1771) (57.6%). Multiple infections were more pronounced in the age group 1-10 (40.1%). Subjects that were farmers were more prone to coinfection. Intestinal parasitic infection and malaria coinfection is a serious health challenge in Oke-Oyi Area of Kwara State, North Central Nigeria. Therefore, concerted efforts such as mass deworming, improved sanitation, provision of toilet facilities and health education is encouraged.

A cluster-randomised controlled trial integrating a community-based water, sanitation and hygiene programme, with mass distribution of albendazole to reduce intestinal parasites in Timor-Leste: the WASH for WORMS research protocol

IntroductionThere is limited evidence demonstrating the benefits of community-based water, sanitation and hygiene (WASH) programmes on infections with soil-transmitted helminths (STH) and intestinal protozoa. Our study aims to contribute to...

The Role of Child Health Days in the Attainment of Global Deworming Coverage Targets among Preschool-Age Children.

BackgroundGlobal deworming programs aim to reach 75% of at-risk preschool-age children (pre-SAC) by 2020. The 2013 global pre-SAC deworming coverage initially published by the World Health Organization (WHO) was 23.9%, but this estimate inadequately captured deworming delivered through Child Health Day (CHD) platforms.ObjectiveTo update global and regional coverage estimates of pre-SAC deworming in 2013 by supplementing data from the WHO Preventive Chemotherapy and Transmission Control (PCT) databank with national CHD data.MethodsUNICEF country offices (n = 82) were mailed a questionnaire in July 2014 to report on official national biannual CHD deworming coverage as part of the global vitamin A supplementation coverage reporting mechanism. Coverage data obtained were validated and considered for inclusion in the PCT databank in a collaboration between UNICEF and WHO. Descriptive statistical analyses were conducted to update the number of pre-SAC reached and the number of treatments delivered.ResultsOf the 47 countries that responded to the UNICEF pre-SAC deworming questionnaire, 73 data points from 39 countries were considered for inclusion into the WHO PCT databank. Of these, 21 new data points were from 12 countries were newly integrated into the WHO database. With this integration, deworming coverage among pre-SAC increased to 49.1%, representing an increase in the number of children reached and treatments administered from 63.7 million to 130.7 million and 94.7 million to 234.8 million, respectively. The updated databank comprised 98 mass deworming activities conducted in 55 countries, in which 80.4% of the global pre-SAC population requiring deworming reside. In all, 57 countries requiring deworming were not yet represented in the database.ConclusionsWith the inclusion of CHD data, global deworming programs are on track to achieving global pre-SAC coverage targets. However, further efforts are needed to improve pre-SAC coverage reporting as well as to sustain and expand deworming delivery through CHDs and other platforms.

The Case for Mass Treatment of Intestinal Helminths in Endemic Areas.

Two articles published earlier this year in the International Journal of Epidemiology [1,2] have re-ignited the debate over the World Health Organization’s long-held recommendation of mass-treatment of intestinal helminths in endemic areas. In this note, we discuss the content and relevance of these articles to the policy debate, and review the broader research literature on the educational and economic impacts of deworming. We conclude that existing evidence still indicates that mass deworming is a cost-effective health investment for governments in low-income countries where worm infections are widespread.

Authors' Response to: Deworming externalities and school impacts in Kenya.

1. Aiken A, Davey C, Hargreaves J, Hayes R. Re-analysis of health and educational impacts of a school-based deworming program in western Kenya: a pure replication. Int J Epidemiol 2015; 44:1572–80. 2. Davey C, Aiken A, Hayes R, Hargreaves J. Re-analysis of health and educational impacts of a school-based deworming programme in western Kenya: a statistical replication of a cluster quasi-randomized stepped-wedge trial., Int J Epidemiol 2015; 44:1581–92. 3. Miguel E, Kremer M. Worms: identifying impacts on education and health in the presence of treatment externalities. Econometrica 2004;72:159–217. 4. Aiken A, Davey C, Hargreaves J, Hayes R. Re-Analysis of Health and Educational Impacts of a School-Based Deworming Program in Western Kenya: Part 1: Pure Replication. 3ie Replication Paper 3, part 1. Washington, DC: International Initiative for Impact Evaluation (3ie), 2014. 5. Hicks JH, Kremer M, Miguel E. (a) Estimating Deworming School Participation Impacts and Externalities in Kenya: A Comment on Aiken et al. Original author response to 3ie Replication Paper 3, Part 1. Washington, DC: International Initiative For Impact Evaluation (3ie), 2014. 6. Davey C, Aiken A, Hayes R, Hargreaves,J. Re-Analysis of Health and Educational Impacts of a School-Based Deworming Program in Western Kenya: Part 2: Alternative Analyses. 3ie Replication Paper 3, Part 2. Washington, DC: International Initiative For Impact Evaluation (3ie), 2014. 7. Hicks JH, Kremer M, Edward M. (b). Estimating Deworming School Participation Impacts in Kenya: A Comment on Aiken et al. Original author response to 3ie Replication Paper 3, part 2. Washington, DC: International Initiative for Impact Evaluation (3ie), 2014. 8. Aiken A, Davey C, Hayes R, Hargreaves J. Deworming Schoolchildren in Kenya – Replication Plan. Washington, DC: International Institute Impact Evaluation (3ie), 2013. 9. Am Ahuja, Baird S, Hamory Hicks J, Kremer M, Miguel E, Powers S. When Should Governments Subsidize Health? The Case of Mass Deworming. National Bureau of Economic Research Working Paper #21148. Cambridge, MA: National Bureau of Economic Research, 2015. 10. Bleakley H. Disease and development: evidence from hookworm eradication in the American South. Q J Econ 2007;122:73–117. 11. Ozier O. Exploiting Externalities to Estimate the Long-Term Effects of Early Childhood Deworming. World Bank Policy Research Working Paper #7052, Washington, DC: World Bank, 2014.

The epidemiology of soil-transmitted helminths in Bihar State, India.

BackgroundSoil-transmitted helminths (STHs) infect over a billion individuals worldwide. In India, 241 million children are estimated to need deworming to avert the negative consequences STH infections can have on child health and development. In February-April 2011, 17 million children in Bihar State were dewormed during a government-led school-based deworming campaign. Prior to programme implementation, a study was conducted to assess STH prevalence in the school-age population to direct the programme. The study also investigated risk factors for STH infections, including caste, literacy, and defecation and hygiene practices, in order to inform the development of complementary interventions.MethodsA cross-sectional survey was conducted among children in 20 schools in Bihar. In addition to providing stool samples for identification of STH infections, children completed a short questionnaire detailing their usual defecation and hand-hygiene practices. Risk factors for STH infections were explored.ResultsIn January-February 2011, 1279 school children aged four to seventeen provided stool samples and 1157 children also completed the questionnaire. Overall, 68% of children (10-86% across schools) were infected with one or more soil-transmitted helminth species. The prevalence of ascariasis, hookworm and trichuriasis was 52%, 42% and 5% respectively. The majority of children (95%) practiced open defecation and reported most frequently cleansing hands with soil (61%). Increasing age, lack of maternal literacy and certain castes were independently associated with hookworm infection. Absence of a hand-washing station at the schools was also independently associated with A. lumbricoides infection.ConclusionsSTH prevalence in Bihar is high, and justifies mass deworming in school-aged children. Open defecation is common-place and hands are often cleansed using soil. The findings reported here can be used to help direct messaging appropriate to mothers with low levels of literacy and emphasise the importance of water and sanitation in the control of helminths and other diseases.

Deworming Campaign in Eastern Afghanistan – Prevalence of Intestinal Parasites and Adoption of Treatment Strategy

Purpose: To estimate the prevalence and species of intestinal parasites in an Afghan community as well as to establish appropriate treatment method for each of the detected pathogens.Methods: Parasitological examination of stool samples collected from 777 children aged 1-17 years, treated in Ghazni Provincial Hospital (eastern Afghanistan) conducted in the period 2012 - 2013 made it possible to implement dedicated antiparasitic treatment.Results: Of 312 children (40.2 % of the examined group; p < 0.05) infected with nematodes (n = 154, 19.7 %), cestodes (n = 90, 11.6 %), trematodes (n = 16, 2.1 %), and protozoa (n = 135, 17.4 %), 67 were diagnosed with co-infections (mainly ascariasis + giardiasis, ascariasis + hymenolepiasis, giardiasis + hymenolepiasis, ascariasis + giardiasis + hymenolepiasis) and received complex therapy (albendazole + metronidazole, albendazole + praziquantel, metronidazole + praziquantel, and albendazole + metronidazole + praziquantel).Conclusion: Owing to high prevalence of multiple co-infections among inhabitants of the Afghan community, it seems that a mass deworming campaign with a single-dose chemotherapy (albendazole 400 mg or mebendazole 500 mg) may prove ineffective in eradicating intestinal parasites in the local population.Keywords: Afghanistan, Intestinal parasites, Hymenolepiasis, Ascariasis, Giardiasis, Metronidazole, Albendazole, Praziquantel, Mebendazole, Deworming

Major Risk Factors Predicting Anemia Development during Pregnancy: Unmatched-Case Control Study

Background: Anemia in pregnancy is associated with increased rates of maternal and perinatal mortality, premature delivery and other adverse outcomes. Hence, identifying anemia predicting risk factors in high-risk groups such as pregnant women is essential for problem based intervention modalities, particularly for developing countries. The aim of this study was to identify the major risk factors predictive of anemia development during pregnancy in Hawassa and Yirgalem cities located in Sidama Zone, Ethiopia. Methods: Unmatched case-control study, involving 561 pregnant women who initiated antenatal care follow up during their first trimester, was conducted from February to March 2011. Socio-demographic, hemoglobin level, obstetric and medical data of the study participants were collected using pre-tested well-structured questionnaire and reviewing antenatal care follow up record cards of each pregnant woman. Hemoglobin level <11 g/dl was used to define anemia during pregnancy. Bivariate and multivariate analyses were conducted to find predictors of anemia, P-value <0.05 was considered as statistically significant. Results: The major predicting risk factors for occurrence of anemia among pregnant women were, lower educational level (AOR=3.3, 95% CI: 1.3-8.0, P=0.007), prolonged menstruation period 6-8 days before the index pregnancy (AOR=3.1, 95% CI: 1.6-5.9., P=0.001), intestinal parasitic infection (AOR=2.9, 95% CI: 1.4-8.1, P=0.000), gastritis with duodenal ulcer bleeding (AOR=3.87, 95% CI: 1.8-8.0, P=0.000) and not taking meat/organ meats (AOR=2.8, 95% CI: 1.3-6.1, P=0.008). Conclusions: Family illiteracy, intestinal parasitic infection, duration of menstrual bleeding, gastritis with duodenal ulcer bleeding, and inadequate intake of organ meats were identified as strong predicting risk factors of anemia among pregnant women. Therefore, to reduce maternal mortality, the overall anemia prevention strategy in pregnant women should promote community-based health education to low educated families, mass de-worming of intestinal parasites and focused counseling for those women who have prolonged menstruation and peptic ulcer diseases.

When Should Governments Subsidize Health? The Case of Mass Deworming

We discuss how evidence and theory can be combined to provide insight on the appropriate subsidy level for health products, focusing on the specific case of deworming. Although intestinal worm infections can be treated using safe, low-cost drugs, some have challenged the view that mass school-based deworming should be a policy priority. We review well-identified research which both uses experimental or quasi-experimental methods to demonstrate causal relationships and adequately accounts for epidemiological externalities from deworming treatment, including studies of deworming campaigns in the Southern United States, Kenya, and Uganda. The existing evidence shows consistent positive impacts on school participation in the short run and on academic test scores, employment, and income in the long run, while suggesting that most parents will not pay for deworming treatment that is not fully subsidized. There is also evidence for a fiscal externality through higher future tax revenue, which may exceed the cost of the program. Our analysis suggests that the economic benefits of school-based deworming programs are likely to exceed their costs in places where worm infestations are endemic. This would likely be the case even if the benefits were only a fraction of estimates in the existing literature.

Epidemiology of intestinal parasitic infections in school children in Ghazni Province, eastern Afghanistan.

Objective:To estimate the prevalence of intestinal parasites and their species in Afghan school children and to establish appropriate treatment methods for detected pathogens.Methods:Parasitological examination of stool samples collected from 1369 children aged 8-18, students of the Jahan Malika High School in Ghazni Province in eastern Afghanistan, was conducted in the period November 2013-April 2014. Three stool samples were collected from each patient every second day; the samples were fixed in 10% formalin and tested by light microscopy using the methods of direct smear in Lugol’s solution, decantation in distilled water, and Fülleborn’s flotation.Results:Of 535 examined children (39.1% of the study group) were infected with nematodes (n=324), cestodes (n=118), trematodes (n=12), and protozoa (n=228), 132 were diagnosed with co-infections (mainly ascariasis+giardiasis, ascariasis+hymenolepiasis) and received single or combined therapy.Conclusions:The Afghan community is an example of population characterized by a high rate of parasitic infections. Owing to high prevalence of multiple infections among inhabitants of Afghanistan, it seems that a mass deworming campaign with a single-dose chemotherapy may prove ineffective in eradicating intestinal parasites in the local population.

Effects of a post-deworming health hygiene education intervention on absenteeism in school-age children of the Peruvian Amazon.

Soil-transmitted helminth (STH) infections are a leading cause of disability and disease burden in school-age children of worm-endemic regions. Their effect on school absenteeism, however, remains unclear. The World Health Organization currently recommends delivering mass deworming and health hygiene education through school-based programs, in an effort to control STH-related morbidity. In this cluster-RCT, the impact of a health hygiene education intervention on absenteeism was measured. From April to June 2010, all Grade 5 students at 18 schools in a worm-endemic region of the Peruvian Amazon were dewormed. Immediately following deworming, nine schools were randomly assigned to the intervention arm of the trial using a matched-pair design. The Grade 5 students attending intervention schools (N = 517) received four months of health hygiene education aimed at increasing knowledge of STH prevention. Grade 5 students from the other nine schools (N = 571) served as controls. Absenteeism was measured daily through teachers' attendance logs. After four months of follow-up, overall absenteeism rates at intervention and control schools were not statistically significantly different. However, post-trial non-randomized analyses have shown that students with moderate-to-heavy Ascaris infections and light hookworm infections four months after deworming had, respectively, missed 2.4% (95% CI: 0.1%, 4.7%) and 4.6% (95% CI: 1.9%, 7.4%) more schooldays during the follow-up period than their uninfected counterparts. These results provide empirical evidence of a direct effect of STH infections on absenteeism in school-age children.

Evaluation of circulating cathodic antigen (CCA) urine-cassette assay as a survey tool for Schistosoma mansoni in different transmission settings within Bugiri District, Uganda

Diagnosis of schistosomiasis at the point-of-care (POC) is a growing topic in neglected tropical disease research. There is a need for diagnostic tests which are affordable, sensitive, specific, user-friendly, rapid, equipment-free and delivered to those who need it, and POC is an important tool for disease mapping and guiding mass deworming. The aim of present study was to evaluate the relative diagnostic performance of two urine-circulating cathodic antigen (CCA) cassette assays, one commercially available and the other in experimental production, against results obtained using the standard Kato-Katz faecal smear method (six thick smears from three consecutive days), as a ‘gold-standard’, for Schistosoma mansoni infection in different transmission settings in Uganda. Our study was conducted among 500 school children randomly selected across 5 schools within Bugiri district, adjacent to Lake Victoria in Uganda. Considering results from the 469 pupils who provided three stool samples for the six Kato-Katz smears, 293 (76%) children had no infection, 109 (23%) were in the light intensity category, while 42 (9%) and 25 (5%) were in the moderate and heavy intensity categories respectively. Following performance analysis of CCA tests in terms of sensitivity, specificity, negative and positive predictive values, overall performance of the commercially available CCA test was more informative than single Kato-Katz faecal smear microscopy, the current operational field standard for disease mapping. The current CCA assay is therefore a satisfactory method for surveillance of S. mansoni in an area where disease endemicity is declining due to control interventions. With the recent resolution on schistosomiasis elimination by the 65th World Health Assembly, the urine POC CCA test is an attractive tool to augment and perhaps replace the Kato-Katz sampling within ongoing control programmes.

Perceived illness drives participation in mass deworming campaigns in Laos

Multiple helminth infections are very common in communities of southern Laos. Preventive chemotherapy in combination with health education is the mainstay of control. We assessed the knowledge, perceptions and practices of rural communities related to endemic helminthiasis and their control during a mass drug administration (MDA) campaign. Short interviews with household heads (n=192), direct observations and discussions with attendees of MDAs, and in-depth interviews with local opinion leaders (n=21) were carried out. Quantitative and qualitative data analysis was performed. Results showed that opinion leaders and villagers were well aware of the importance of attending MDA. Leaders perceived the effectiveness of MDA against severe schistosomiasis and appreciated that it was provided for free and in their village. They encouraged villagers to attend it. Anticipated adverse events of praziquantel was a barrier for participation. A majority of leaders purchased deworming tablet (mebendazole, albendazole) in a local pharmacy for deworming when MDA is absent in their villages (19/21). Most leaders (20/21) had a good knowledge on severe schistosomiasis though only a few of them (5/21) described its cause correctly. They knew little about the disease consequences of liver fluke (3/21) and soil-transmitted helminth (4/21) infections but more about their causes. A high risk for worm infection was observed: consumption of raw or insufficiently cooked fish (100%), frequent physical contacts with Mekong River water (76.0%) and low number of latrines (14.5%). In conclusion, MDA is widely accepted in affected communities. Avoiding severe schistosomiasis was the main motivation to comply. Participation rates increased significantly with drugs provided free of charge in the villages. Better knowledge on the consequences of worm infections and on its modes of transmission will foster the distribution and acceptance of appropriate preventive treatment and other measures in helminth-endemic communities. Where multiple infections require several drugs for MDA, preceding health education and information about MDA and its benefits are a prior condition.

Soil-Transmitted Helminthiases in Secondary School Students in Selected Sites in Two Provinces in the Philippines: Policy Implications

The latest World Health Organization (WHO) strategic plan for eliminating soil-transmitted helminthiases (STHs) as a public health problem in children puts the emphasis on school-age children. On the other hand, the Philippine national helminth control program excludes secondary school students in mass deworming for STH. This study determined the prevalence and intensity of STH in a sample of 633 students (14-15 years old) in selected secondary schools in two Philippine provinces. Stool specimens were processed following the Kato-Katz technique and examined for the presence of helminth ova. Overall cumulative prevalence of STH was 31.3%, while prevalence of moderate-heavy-intensity infections was 7.7%, well beyond the WHO target of ≤1% for reducing morbidity in school-age children. Recommendations were made to update the Philippine helminth control program and to re-examine the WHO strategic plan so that helminth prevention and control strategies may also be emphasized for secondary school students especially in high-prevalence areas.

Diagnóstico de situación de la equinococosis quística en heces dispersas en las zonas de Quebrada y Puna, provincia de Jujuy, Argentina

Echinococcosis is a parasitic disease common in livestock, caused by the cestode Echinococcus granulosus, the dog being the principal definitive host. The province of Jujuy is an endemic area located in the Northwest of Argentina. Due to the restricted ecological conditions of Quebrada and Puna, the most important activity of the population is formal cattle pastoralism and transhumance, especially of sheep and camelids. The dog acquires the double function of company and shepherd in these communities. The objective of the present study was to conduct a diagnosis of the situation in areas of La Quebrada and Puna where the circulation of E. granulosus is suspected. Five hundred and twenty three (523) samples of canine fecal material scattered in the environment were collected from 2002 to 2012. Prevalence varied from 2% in Susques to 27.7% in Humahuaca, the largest in the province. In Tumbaya, prevalence was 21% in the year 2007, reaching 0% in the year 2010 but increasing again to 10.5% in the year 2011. These results may be related to health education on preventive measures and mass deworming held prior to sample taking in the year 2010. A prevalence between 19.4% and 2% was observed in the rest of the regions studied, suggesting that a lack of strategies for echinococcosis control has allowed the spread of the disease.

Rural Rabies Prevention Project - A ‘One Health’ Experiment in India: An Overview

Aim: To assess the feasibility of implementing approach to prevent human rabies and control animal rabies in a rural community. Study Design: Health research in a rural setting. Place and Duration of Study: A medical college and a veterinary college along with an animal welfare organization delivered a wide array of integrated services in three villages' i.e. Kumbalagodu, Thagachikuppe and Gerupalya near Bangalore, India comprising a population of 10,220 persons for a period of two years from December, 2009 to November, 2011. The nearby three villages of Ramohally, Vinayakanagara and Bhimanakuppe with a population of 6,023 persons formed the control group, with no project inputs. Methodology: This consisted of household surveys at the beginning and end of two years ; rabies awareness campaigns; clinical and laboratory surveillance of rabies in dogs; rabies post-exposure prophylaxis (PEP) in humans; pre-exposure rabies prophylaxis (PrEP) by intradermal route in school children, pet dog owners and veterinarians ; mass dog vaccination and deworming; and sero-surveillance in both dogs and humans. Results: The ratio of veterinary and medical manpower in study villages was 1: 11 and dog to human ratio was 1: 23.The information, education and communication materials developed and used were domestic outdoor wall writings (11), domestic indoor annual wall calendar (2000), school book labels (1000); game charts (16); wall posters (65); flip chart (15); rabies educational DVD (1). There were 102 local cable television transmissions on rabies prevention. 69 persons received rabies PEP. PrEP was given to 368 school children, pet dog owners and veterinarians. Sixty one human serum samples were analyzed by rapid fluorescent focus inhibition test for rabies antibody detection. Sixteen veterinarians were trained to use direct rapid immunohistochemical test (dRIT) for rabies diagnosis. Six ruminants were confirmed rabid by dRIT. There were no cases of human rabies. The cost of entire project was US $ 85,958. Conclusion: A blend of medical, veterinary and animal welfare were successfully delivered through a health approach. Based on this success a conceptual model was evolved to propagate its replication in other rural communities across India.

Efficacy of Praziquantel against Schistosoma haematobium in Dulshatalo village, western Ethiopia

BackgroundPraziquantel (PZQ) is the drug of choice for treatment of all human schistosomes. It is used in population based targeted or mass deworming strategies in several countries. The effect of PZQ on S. hematobium has not been studied in Ethiopia. The objective of this study was to determine the efficacy of PZQ against S. haematobium in Dulshatalo village, western Ethiopia.MethodsA prospective study was conducted from October to December, 2007. Urine samples from 341 residents were collected and screened for haematuria and proteinuria using urinalysis dipstick. S. haematobium eggs were detected and quantified using filtration techniques. The participants who were positive for haematuria were treated with a standard dose of PZQ (40 mg/kg). Data on pre and 24 hours post treatment symptoms were collected via questionnaire. Urine samples were also collected 7 weeks after treatment and examined to assess the cure and the egg reduction rates.ResultsThe prevalence of S. haematobium among the study participants was 57.8% (197/341). Haematuria was detected in 234 (68.6%) of the study participants. For PZQ efficacy asessment, 152 of the treated participants were considered. The presence of S. haemetaobium eggs showed statistically significant association (p < 0.05) with haematuria and proteinuria. Seven weeks post treatment, the extent of haematuria and proteinuria decreased from 100% to 40.8% and 94.07% to 48.7%, respectively. The cure and the parasitological egg reduction rates seven weeks post treatment were 86% and 85%, respectively. Post treatment symptoms revealed a wide range of side effects including straining, abdominal pain, nausea and headache.ConclusionsThere were marked cure and egg reduction rates, together with mild and short lived side effects of PZQ for treatment of S. haematobium, in this study.

To Deworm or not to Deworm: that is the question

I am writing to comment on your article in the March issue (Pathogens in Global Health Volume 107 Issue No.2) titled ‘Factors associated with parasitic infection amongst street children in orphanages across Lima, Peru’ by Bailey, et al. I am a pediatrician working for the Anglican Church in health programs that span the entire city of Lima. I was thrilled to see an article that addresses actual data of parasite frequency among marginalized populations in Lima. There is quite a bit of data regarding parasite incidence in general in Peru, but as evidenced by the references of the article, there has been a relative paucity of zonal data for the city of Lima. When present, this data seems to vary significantly, as in this article, the cited 2006 article (Iannaconne, et al, 2006), and an article by the same author in 2007 (Iannaconne, et al, 2007), a situation that calls for further investigation and definition of the problem. The data from the March study almost exactly matches our internal data gathered from regions as geographically disparate as San Juan de Miraflores in the southern cone of the city and Ventanilla in the northern cone of the city. The important point regarding this variation is that the different data indicate different answers to an important question: Should we initiate and/or support standardized programs to combat intestinal helminthes in the Lima metropolitan area? The World Health Organization recommendations on this point are clear, with 20% incidence as the accepted threshold for single dose treatment with albendazole for T. Trichura, A. duodenolae/N. Americanus, and A. lumbriciodes (Preventative Chemotherapy in Human Helminthiasis, WHO 2006). There are then different frequencies recommended based on the levels above this threshold. The numbers for the country of Peru as a whole meet the WHO threshold, but most of the data from Lima does not. Among numerous NGOs and even many government clinics, ‘deworming’ programs are the accepted policy, normally using a single treatment albendazole, 400 mg. A question that is alarmingly missing from such practice is - What are we treating when we do this? The answer seems to be: not much. As noted in the study, the most frequent pathogenic organism is G. Lamblia. While a longer course of albendazole has shown to be effective for G. Lamblia, a single dose treatment is ineffective, and it is unlikely that blanket treatment for this pathogenic protozoan would be effective anyway due to the high rate of re-infection in the absence of other extensive interventions. It was disappointing in the discussion section that the intestinal helminthes were not further subcategorized into intestinal nematodes and intestinal cestodes. The treatment for the two is fundamentally different. The nematodes respond to treatment with standard albendazole, but the cestodes (specifically H. nana in this case) are treated with praziquantel, a relatively expensive medicine that is used in mass deworming for schistosomiasis and in treatment of other parasitic disease. Thus, the total ‘intestinal helminth’ figure listed was deceptively high for assessing the need for implementing a deworming program. The susceptible helminthes for an albendazole program (nematodes) were only at about 8%. As stated, the threshold for standard deworming for these pathogens sits at 20% according to the World Health Organization. Anywhere below this number, individual treatment is the standard. While Peru’s numbers in general may be above the WHO standard, these are numbers that also include the mountains, and more importantly, the jungle, where the soil transmitted nematode rate would be much higher. The city of Lima represents a much different incidence and deserves very different consideration when instituting treatment protocols. What are the downsides of indiscriminate use of albendazole, a relatively safe medicine? The obvious possible drawbacks include adverse reactions (admittedly low with this medicine) and resource wastage. However, there is a more subtle problem as well. If we are focused on the wrong pathogen (i.e. the wrong problem), then both the medical community and the individual patients and families risk not focusing on the correct problems, which are many. In the interest of reasonable resource utilization for marginalized populations, it is imperative to further define the pathogenic problems for the micro-communities of Lima. I applaud the authors for their contribution to the discussion, and I look forward to further scientific inquiry into optimal approaches for treatment and resource allocation.

Routine Deworming of Children at Deployed Military Healthcare Facilities

The World Health Organization advocates mass antihelminthic treatment of school-age children in areas of high prevalence of soil-transmitted helminths. Soil-transmitted helminths prevalence in Afghanistan is 20-50%, but a high proportion of children do not attend school, so may be missed by deworming programs. The primary function of military medical assets in a theater of war is to provide life, limb and eyesight saving treatment. Additional humanitarian aid in the form of nonemergency treatment has also been provided in Afghanistan for thousands of civilian children. Children represent 3-15% of the patients treated at deployed military medical facilities. We report on recent experience of deployed surgical teams in southern Afghanistan who have noticed high levels of soil-transmitted helminths in war-injured patients. Military medical assets may provide an opportunity to integrate a policy of deworming of children into existing programs of humanitarian support. This would not be a substitute for mass deworming programs, but a supplementation.