World NTD Day 2022 and a new Kigali Declaration to galvanise commitment to end neglected tropical diseases

The World Health Organization’s first roadmap and the London Declaration on neglected tropical diseases (NTDs) have allowed an unprecedented expansion of interventions to control and eliminate this group of infectious diseases that primarily affects vulnerable or marginalised communities. The 2021–2030 NTD roadmap sustains a further acceleration of interventions but also introduces a broader and more ambitious agenda, calling to be accompanied by a new political declaration. Sponsored by the Government of Rwanda, the Kigali Declaration on neglected tropical diseases will be launched in 2022 to renew and reinvigorate commitments to end NTDs, also in the wake of the current setback caused by the COVID-19 pandemic. Starting on World NTD Day 2022, a global campaign “100% Committed” will call on a broad range of stakeholders to sign the declaration and make bold financial and political commitments towards achieving the 2030 roadmap and Sustainable Development Goals’ targets for NTDs.

Evaluation of the therapeutic efficacy of praziquantel against schistosomes in seven countries with ongoing large-scale deworming programs

The World Health Organization (WHO) recommends periodic assessment of the therapeutic efficacy of praziquantel (PZQ) to detect reduced efficacy that may arise from drug resistance in schistosomes. In this multi-country study (2014), we assessed the therapeutic efficacy of a single oral dose of PZQ (40 mg/kg) against Schistosoma mansoni (Brazil, Cameroon, Ethiopia, Mali, Madagascar and Tanzania), S. haematobium (Cameroon, Ethiopia, Mali, Tanzania and Zanzibar) and S. japonicum (the Philippines) infections in school-aged children, across a total of 12 different trials. Each trial was performed according to the standardized methodology for evaluating PZQ efficacy as described by the WHO. Overall, therapeutic efficacy, measured as the reduction in arithmetic mean of schistosome egg counts following drug administration (egg reduction rate; ERR), was high for all three schistosome species (S. mansoni: 93.4% (95%CI: 88.8–96.8); S. haematobium: 97.7% (95%CI: 96.5–98.7) and S. japonicum: 90.0% (95%CI: 68.4–99.3). At the trial level, therapeutic efficacy was satisfactory (point estimate ERR ≥90%) for all three Schistosoma species with the exception of S. mansoni in Cameroon where the ERR was 88.5% (95%CI: 79.0–95.1). Furthermore, we observed that in some trials individual drug response could vary significantly (wide 95%CI) and that few non-responsive individuals could significantly impact ERR point estimates. In conclusion, these results do not suggest any established reduced efficacy of the standard PZQ treatment to any of the three schistosome species within these countries. Nevertheless, the substantial degree of variation in individual responses to treatment in some countries underpins the need for future monitoring. The reported ERR values serve as reference values to compare with outcomes of future PZQ efficacy studies to ensure early detection of reduced efficacies that could occur as drug pressure continues increase. Finally, this study highlights that 95%CI should be considered in WHO guidelines to classify the therapeutic efficacy of PZQ.

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PZQ efficacy against schistosomes was assessed in school-aged-children in seven countries.

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There was no overall sign of reduced PZQ efficacy against any schistosome species.

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Notable variation in individual responses to treatment does require future monitoring.

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It is recommended to include reporting of the 95%CI in future WHO guidelines.

Integration of prevention and control measures for female genital schistosomiasis, HIV and cervical cancer

Female genital schistosomiasis as a result of chronic infection with Schistosoma haematobium (commonly known as bilharzia) continues to be largely ignored by national and global health policy-makers. International attention for large-scale action against the disease focuses on whether it is a risk factor for the transmission of human immunodeficiency virus (HIV). Yet female genital schistosomiasis itself is linked to pain, bleeding and sub- or infertility, leading to social stigma, and is a common issue for women in schistosomiasis-endemic areas in sub-Saharan Africa. The disease should therefore be recognized as another component of a comprehensive health and human rights agenda for women and girls in Africa, alongside HIV and cervical cancer. Each of these three diseases has a targeted and proven preventive intervention: antiretroviral therapy and pre-exposure prophylaxis for HIV; human papilloma virus vaccine for cervical cancer; and praziquantel treatment for female genital schistosomiasis. We discuss how female genital schistosomiasis control can be integrated with HIV and cervical cancer care. Such a programme will be part of a broader framework of sexual and reproductive health and rights, women's empowerment and social justice in Africa. Integrated approaches that join up multiple public health programmes have the potential to expand or create opportunities to reach more girls and women throughout their life course. We outline a pragmatic operational research agenda that has the potential to optimize joint implementation of a package of measures responding to the specific needs of girls and women.

Control of taeniasis and cysticercosis in China

National surveys suggest that the prevalence of taeniasis has considerably decreased in China, while reported cases indicated T. solium cysticercosis was historically highly endemic in northeastern, central and southwestern China. The high prevalence of taeniasis and cysticercosis there was driven by socio-ecological determinants. Cysticercosis may occur in the central nervous system, spinal cord, subcutaneous muscle, eyes, heart and oral cavity. Neurocysticercosis, the clinically most important type, causes epilepsy, increased intracranial pressure and neuropsychiatric symptoms. New molecular diagnostic techniques have been introduced for high sensitivity and discrimination of Taenia species. Immunological methods remain useful in the diagnosis of cysticercosis, especially neurocysticercosis. The introduction of imaging techniques including computed tomography and magnetic resonance imaging has significantly improved the diagnosis of neurocysticercosis. Recently, a combination of pumpkin seeds and areca nut has been explored against taeniasis, while praziquantel and albendazole are administrated simultaneously against cysticercosis, with promising efficacy and low side-effects. The widespread adoption of deworming protocols and techniques for inspection, management and treatment of pigs as well as improved sewage management has contributed to the significant decrease of taeniasis and cysticercosis in northern China. The positive results of these techniques should now be extended to highly endemic areas in western China to achieve the national elimination target for taeniasis and cysticercosis. Elimination of taeniasis and cysticercosis in China will not only benefit public health within China but also set an important example for less developed countries.

The molecular speciation of soil-transmitted helminth eggs collected from school children across six endemic countries

BACKGROUND

The diagnosis of soil-transmitted helminths (STHs; Ascaris, Trichuris and hookworms) is traditionally based on the demonstration of eggs in stool using microscopic techniques. While molecular techniques are more appropriate to speciate STH species they are seldom applied. In this study we speciated STH eggs from stool using molecular techniques to gain insights into the distribution of both human and animal STH species in the human host.

METHODS

We speciated 207 STH egg isolates from stool collected during the baseline survey of six drug efficacy trials conducted in Brazil, Cambodia, Cameroon, Ethiopia, Tanzania and Vietnam applying a PCR - restriction fragment length polymorphisms based approach.

RESULTS

DNA of Ascaris was detected in 71 (34.3%) samples, of which all were identified as the human roundworm Ascaris lumbricoides. In 87 (42.0%) samples, DNA of Trichuris spp. was found and further speciation demonstrated the presence of the human Trichuris trichiura (100%) and the canine Trichuris vulpis (n=7; 8.0%; in Cameroon only). Hookworms were identified in 104 (50.2%) samples, with Necator americanus (n=73; 70.2%) being the predominant species followed by Ancylostoma duodenale (n=40; 38.5%).

CONCLUSIONS

Our study indicates that STH infections in humans are predominantly caused by human STH species. They also suggest that zoonotic transmission occurs on a local scale.

Neglected tropical diseases: an effective global response to local poverty-related disease priorities

Background

Neglected tropical diseases (NTDs) have long been overlooked in the global health agenda. They are intimately related to poverty, cause important local burdens of disease, but individually do not represent global priorities. Yet, NTDs were estimated to affect close to 2 billion people at the turn of the millennium, with a collective burden equivalent to HIV/AIDS, tuberculosis, or malaria. A global response was therefore warranted.

Main text

The World Health Organization (WHO) conceived an innovative strategy in the early 2000s to combat NTDs as a group of diseases, based on a combination of five public health interventions. Access to essential NTD medicines has hugely improved thanks to strong public-private partnership involving the pharmaceutical sector. The combination of a WHO NTD roadmap with clear targets to be achieved by 2020 and game-changing partner commitments endorsed in the London Declaration on Neglected Tropical Diseases, have led to unprecedented progress in the implementation of large-scale preventive treatment, case management and care of NTDs. The coming decade will see as challenges the mainstreaming of these NTD interventions into Universal Health Coverage and the coordination with other sectors to get to the roots of poverty and scale up transmission-breaking interventions. Chinese expertise with the elimination of multiple NTDs, together with poverty reduction and intersectoral action piloted by municipalities and local governments, can serve as a model for the latter. The international community will also need to keep a specific focus on NTDs in order to further steer this global response, manage the scaling up and sustainment of NTD interventions globally, and develop novel products and implementation strategies for NTDs that are still lagging behind.

Conclusions

The year 2020 will be crucial for the future of the global response to NTDs. Progress against the 2020 roadmap targets will be assessed, a new 2021–2030 NTD roadmap will be launched, and the London Declaration commitments will need to be renewed. It is hoped that during the coming decade the global response will be able to further build on today’s successes, align with the new global health and development frameworks, but also keep focused attention on NTDs and mobilize enough resources to see the effort effectively through to 2030.

The public health control of scabies: priorities for research and action

Scabies is a parasitic disease of the skin that disproportionately affects disadvantaged populations. The disease causes considerable morbidity and leads to severe bacterial infection and immune-mediated disease. Scientific advances from the past 5 years suggest that scabies is amenable to population-level control, particularly through mass drug administration. In recognition of these issues, WHO added scabies to the list of neglected tropical diseases in 2017. To develop a global control programme, key operational research questions must now be addressed. Standardised approaches to diagnosis and methods for mapping are required to further understand the burden of disease. The safety of treatments for young children, including with ivermectin and moxidectin, should be investigated. Studies are needed to inform optimum implementation of mass treatment, including the threshold for intervention, target, dosing, and frequency. Frameworks for surveillance, monitoring, and evaluation of control strategies are also necessary.

The cross-cutting contribution of the end of neglected tropical diseases to the sustainable development goals

The Sustainable Development Goals (SDGs) call for an integrated response, the kind that has defined Neglected Tropical Diseases (NTDs) efforts in the past decade.NTD interventions have the greatest relevance for SDG3, the health goal, where the focus on equity, and its commitment to reaching people in need of health services, wherever they may live and whatever their circumstances, is fundamentally aligned with the target of Universal Health Coverage. NTD interventions, however, also affect and are affected by many of the other development areas covered under the 2030 Agenda. Strategies such as mass drug administration or the programmatic integration of NTD and WASH activities (SDG6) are driven by effective global partnerships (SDG17). Intervention against the NTDs can also have an impact on poverty (SDG1) and hunger (SDG2), can improve education (SDG4), work and economic growth (SDG8), thereby reducing inequalities (SDG10). The community-led distribution of donated medicines to more than 1 billion people reinforces women's empowerment (SDG5), logistics infrastructure (SDG9) and non-discrimination against disability (SDG16). Interventions to curb mosquito-borne NTDs contribute to the goals of urban sustainability (SDG11) and resilience to climate change (SDG13), while the safe use of insecticides supports the goal of sustainable ecosystems (SDG15). Although indirectly, interventions to control water- and animal-related NTDs can facilitate the goals of small-scale fishing (SDG14) and sustainable hydroelectricity and biofuels (SDG7).NTDs proliferate in less developed areas in countries across the income spectrum, areas where large numbers of people have little or no access to adequate health care, clean water, sanitation, housing, education, transport and information. This scoping review assesses how in this context, ending the epidemic of the NTDs can impact and improve our prospects of attaining the SDGs.

Neglected tropical diseases: progress towards addressing the chronic pandemic

The concept of neglected tropical diseases (NTDs) emerged more than a decade ago and has been recognised as a valid way to categorise diseases that affect the poorest individuals. Substantial progress in control and elimination has been achieved and policy momentum has been generated through continued bilateral, philanthropic, and non-governmental development organisation (NGDO) support, and donations of drugs from pharmaceutical companies. WHO has defined a Roadmap to reach 2020 targets, which was endorsed by member states in a World Health Assembly Resolution in 2013. NTDs have been included within the Sustainable Development Goal targets and are a crucial component of universal health coverage, conceptualised as "leaving no one behind". WHO reported that more than 1 billion people in 88 countries have benefited from preventive chemotherapy in 2014. The research agenda has defined the need for affordable products (diagnostics, drugs and insecticides). However challenges such as insecurity and weak health systems continue to prevail in the poorest countries, inhibiting progress in scaling up and also in achieving Roadmap goals.

Water, sanitation and hygiene for accelerating and sustaining progress on neglected tropical diseases: a new Global Strategy 2015-20

Neglected tropical diseases (NTDs) affect over 1 billion people. Safe water, sanitation and hygiene (WASH) contribute to prevention and management of most NTDs. Linking WASH and NTD interventions has potential to impact on multiple NTDs and can help secure sustainable and equitable progress towards universal access to WASH. The need to address the determinants of NTDs has been acknowledged. In response, WHO has published a new Global Strategy: 'Water, Sanitation and Hygiene for accelerating and sustaining progress on Neglected Tropical Diseases'. The Strategy focuses on cross-cutting actions that benefit disease control and care efforts, and strengthen health systems. Implementation of the strategy and the accompanying action plan can help ensure that the health and development agenda leaves no one behind.

Leaving no one behind: a neglected tropical disease indicator and tracers for the Sustainable Development Goals

The Sustainable Development Goals (SDGs) have emerged as a global pledge to 'leave no one behind'. Under SDG 3, 'Ensure healthy lives and promote wellbeing for all', target 3.3 extends the Millennium Development Goals (MDGs) beyond HIV, TB and malaria to 'end the epidemic' of neglected tropical diseases (NTDs) by 2030. Other targets are also relevant to NTDs, especially 3.8 (Universal Health Coverage), 6.1 (water) and 6.2 (sanitation). This commentary summarises the proposed NTD indicator (3.3) and tracers (3.8 and 6.1/6.2). These will help ensure that the world's poorest and most marginalized people are prioritized at every step on the path towards SDG targets.

Assessment of anthelmintic efficacy of mebendazole in school children in six countries where soil-transmitted helminths are endemic

Background

Robust reference values for fecal egg count reduction (FECR) rates of the most widely used anthelmintic drugs in preventive chemotherapy (PC) programs for controlling soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, and hookworm) are still lacking. However, they are urgently needed to ensure detection of reduced efficacies that are predicted to occur due to growing drug pressure. Here, using a standardized methodology, we assessed the FECR rate of a single oral dose of mebendazole (MEB; 500 mg) against STHs in six trials in school children in different locations around the world. Our results are compared with those previously obtained for similarly conducted trials of a single oral dose of albendazole (ALB; 400 mg).

Methodology

The efficacy of MEB, as assessed by FECR, was determined in six trials involving 5,830 school children in Brazil, Cambodia, Cameroon, Ethiopia, United Republic of Tanzania, and Vietnam. The efficacy of MEB was compared to that of ALB as previously assessed in 8,841 school children in India and all the above-mentioned study sites, using identical methodologies.

Principal Findings

The estimated FECR rate [95% confidence interval] of MEB was highest for A. lumbricoides (97.6% [95.8; 99.5]), followed by hookworm (79.6% [71.0; 88.3]). For T. trichiura, the estimated FECR rate was 63.1% [51.6; 74.6]. Compared to MEB, ALB was significantly more efficacious against hookworm (96.2% [91.1; 100], p<0.001) and only marginally, although significantly, better against A. lumbricoides infections (99.9% [99.0; 100], p = 0.012), but equally efficacious for T. trichiura infections (64.5% [44.4; 84.7], p = 0.906).

Conclusions/Significance

A minimum FECR rate of 95% for A. lumbricoides, 70% for hookworm, and 50% for T. trichiura is expected in MEB-dependent PC programs. Lower FECR results may indicate the development of potential drug resistance.

Soil-transmitted helminths (STHs; roundworms, whipworms, and hookworms) infect millions of children in sub-tropical and tropical countries, resulting in malnutrition, growth stunting, intellectual retardation, and cognitive deficits. To fight against STH, large-scale deworming programs are implemented in which anthelmintic drugs (either albendazole (ALB) or mebendazole (MEB)) are administered. Currently, these large-scale programs are intensifying, highlighting the need to closely monitor the efficacy of anthelmintic drugs to detect changes in drug efficacy that may arise through the evolution of anthelmintic drug resistance in the parasites. We have previously defined the minimum expected efficacy of ALB based on the fecal egg count reduction (FECR) rate, but these reference values are lacking for MEB. Therefore, we therefore evaluated the FECR rate of MEB against STHs in six STH endemic countries. In addition, we compared the results of the FECR rate for MEB with those we obtained previously for ALB. The results confirm that MEB treatment was highly efficacious against roundworms, and to a lesser extend against hookworms, but not against whipworms. Compared to ALB, MEB is less efficacious against hookworm, but equally efficacious against roundworms and whipworms. Based on this study we propose the minimum expected FECR rate for MEB-dependent large-scale deworming programs.

Markov model to forecast the change in prevalence of soil-transmitted helminths during a control programme: a case study in Vietnam

BACKGROUND

A mathematical model based on the Markov methodology to predict the change in prevalence of soil-transmitted helminth (STH) infections during public health control activities is not available, but would be an extremely efficient planning tool.

METHOD

We used the parasitological data collected during a deworming and iron supplementation programme for women of child-bearing age conducted in Vietnam between 2006 and 2011 to develop a Markov transition probability model. The transition probabilities were calculated from the observed changes in prevalence in the different classes of intensity for each STH species during the first year of intervention. The model was then developed and used to estimate the prevalence in year 2, 3, 4 and 5 for each STH species and for 'any STH infection'. The prevalence predicted by the model was then compared with the prevalence observed at different times during programme implementation.

RESULTS

The comparison between the model-predicted prevalence and the observed prevalence proved a good fit of the model.

CONCLUSIONS

We consider the Markov transition probability model to be a promising method of predicting changes in STH prevalence during control efforts. Further research to validate the model with observed data in different geographical and epidemiological settings is suggested to refine the prediction model.

Field evaluation of a coproantigen detection test for fascioliasis diagnosis and surveillance in human hyperendemic areas of Andean countries

Background

Emergence of human fascioliasis prompted a worldwide control initiative including a pilot study in a few countries. Two hyperendemic areas were chosen: Huacullani, Northern Altiplano, Bolivia, representing the Altiplanic transmission pattern with high prevalences and intensities; Cajamarca valley, Peru, representing the valley pattern with high prevalences but low intensities. Coprological sample collection, transport and study procedures were analyzed to improve individual diagnosis and subsequent treatments and surveillance activities. Therefore, a coproantigen-detection technique (MM3-COPRO ELISA) was evaluated, using classical techniques for egg detection for comparison.

Methodology and Findings

A total of 436 and 362 stool samples from schoolchildren of Huacullani and Cajamarca, respectively, were used. Positive samples from Huacullani were 24.77% using the MM3-COPRO technique, and 21.56% using Kato-Katz. Positive samples from Cajamarca were 11.05% using MM3-COPRO, and 5.24% using rapid sedimentation and Kato-Katz. In Huacullani, using Kato-Katz as gold standard, sensitivity and specificity were 94.68% and 98.48%, respectively, and using Kato-Katz and COPRO-ELISA test together, they were 95.68% and 100%. In Cajamarca, using rapid sedimentation and Kato-Katz together, results were 94.73% and 93.58%, and using rapid sedimentation, Kato-Katz and copro-ELISA together, they were 97.56% and 100%, respectively. There was no correlation between coproantigen detection by optical density (OD) and infection intensity by eggs per gram of feces (epg) in Cajamarca low burden cases (<400 epg), nor in Huacullani high burden cases (≥400 epg), although there was in Huacullani low burden cases (<400 epg). Six cases of egg emission appeared negative by MM3-COPRO, including one with a high egg count (1248 epg).

Conclusions

The coproantigen-detection test allows for high sensitivity and specificity, fast large mass screening capacity, detection in the chronic phase, early detection of treatment failure or reinfection in post-treated subjects, and usefulness in surveillance programs. However, this technique falls short when evaluating the fluke burden on its own.

A coproantigen-detection technique (MM3-COPRO ELISA) was evaluated in 436 and 362 schoolchildren of Huacullani, Bolivia, and Cajamarca valley, Peru, respectively. Classical techniques for egg detection were used for comparison. In Huacullani, using Kato-Katz as gold standard, sensitivity and specificity were 94.68% and 98.48%, respectively, and using Kato-Katz and COPRO-ELISA test together, they were 95.68% and 100%, respectively. In Cajamarca, using rapid sedimentation and Kato-Katz together, these results were 94.73% and 93.58%, respectively, and using rapid sedimentation, Kato-Katz and copro-ELISA together, results were 97.56% and 100%, respectively. There was no correlation between coproantigen detection by optical density (OD) and infection intensity by eggs per gram of feces (epg) in Cajamarca low burden cases (<400 epg), nor in Huacullani high burden cases (≥400 epg), although there was in Huacullani low burden cases (<400 epg). Six cases of egg emission appeared negative by MM3-COPRO, including one with a high egg count (1248 epg). The coproantigen-detection test allows for high sensitivity and specificity, fast large mass screening capacity, detection in the chronic phase, early detection of treatment failure or reinfection in post-treated subjects, and usefulness for surveillance programs. However, this technique falls short when evaluating the fluke burden on its own.

Administration of triclabendazole is safe and effective in controlling fascioliasis in an endemic community of the Bolivian Altiplano

Background

The Bolivian northern Altiplano is characterized by a high prevalence of Fasciola hepatica infection. In order to assess the feasibility, safety and efficacy of large-scale administration of triclabendazole as an appropriate public health measure to control morbidity associated with fascioliasis, a pilot intervention was implemented in 2008.

Materials and Methods

Schoolchildren from an endemic community were screened for fascioliasis and treated with a single administration of triclabendazole (10 mg/kg). Interviews to assess the occurrence of adverse events were conducted on treatment day, one week later, and one month after treatment. Further parasitological screenings were performed three months after treatment and again two months later (following a further treatment) in order to evaluate the efficacy of the intervention.

Results

Ninety infected children were administered triclabendazole. Adverse events were infrequent and mild. No serious adverse events were reported. Observed cure rates were 77.8% after one treatment and 97.8% after two treatments, while egg reduction rates ranged between 74% and 90.3% after one treatment, and between 84.2% and 99.9% after two treatments. The proportion of high-intensity infections (≥400 epg) decreased from 7.8% to 1.1% after one treatment and to 0% after two treatments.

Conclusion

Administration of triclabendazole is a feasible, safe and efficacious public health intervention in an endemic community in the Bolivian Altiplano, suggesting that preventive chemotherapy can be applied to control of fascioliasis. Further investigations are needed to define the most appropriate frequency of treatment.

Fascioliasis is highly prevalent in the northern Altiplano of Bolivia. We wanted to ascertain whether a preventive chemotherapy approach, involving the large-scale distribution of triclabendazole within endemic communities, would be feasible for controlling morbidity associated with this disease. Consequently, we implemented a pilot intervention among schoolchildren in a community near Lake Titicaca and assessed this intervention's safety (by evaluating the occurrence of adverse events following treatment) and its efficacy (by measuring changes in prevalence and intensity of infection). Adverse events on treatment day, and one week and one month later were infrequent and mild, and no serious adverse events were reported. We observed cure rates of 77.8% after one treatment and 97.8% after two treatments, egg reduction rates of 74–90.3% after one treatment and 84.2–99.9% after two treatments, and a decrease in the proportion of high-intensity infections (≥400 epg) from 7.8% to 1.1% after one treatment and to 0% after two treatments. We conclude that administration of triclabendazole is a safe and efficacious public health intervention for control of fascioliasis in an endemic community in the Bolivian Altiplano. Preventive chemotherapy with triclabendazole, without individual-level diagnosis and treatment, appears therefore as a feasible option. However, further investigation is needed to define the most appropriate frequency of treatment.

Preventive chemotherapy and the fight against neglected tropical diseases

Preventive chemotherapy is the public health strategy recommended by the WHO against a set of neglected tropical diseases that includes four groups of helminth infections (lymphatic filariasis, onchocerciasis, schistosomiasis and soil-transmitted helminthiasis) and one chlamydial (trachoma) infection. This article presents the characteristics of preventive chemotherapy interventions directed against each disease targeted by this strategy and provides an update on the status of their implementation worldwide.

Integrated implementation of programs targeting neglected tropical diseases through preventive chemotherapy: identifying best practices to roll out programs at national scale

In 2006 the U.S. Agency for International Development (USAID) established the Neglected Tropical Disease (NTD) Control Program to support national governments in developing successful, cost-efficient NTD programs that integrate disease-specific programs into coordinated national initiatives, in accord with the World Health Organization recommendations. A 3-stage "roll-out package" has been developed for effectively integrating and scaling up such programs to full-national scale. Stage-1 lays the groundwork-identifying NTD leadership within the Ministry of Health, conducting a national Situation Analysis, formulating a multiyear Plan of Action, and undertaking a funding gap analysis. Stage-2 focuses on scaling up the integrated NTD program-convening national stakeholder meetings, developing annual work plans, carrying out disease mapping, and establishing monitoring and evaluation activities. Stage-3 aims at ensuring effective management-identifying clear roles and responsibilities for partners, and creating a central coordinating mechanism. Assessment and reassessment of these complex NTD programs that target literally billions of people are essential to establish "best practice" strategies for long-term public health success.

Integrated implementation of programs targeting neglected tropical diseases through preventive chemotherapy: identifying best practices to roll out programs at national scale

In 2006 the U.S. Agency for International Development (USAID) established the Neglected Tropical Disease (NTD) Control Program to support national governments in developing successful, cost-efficient NTD programs that integrate disease-specific programs into coordinated national initiatives, in accord with the World Health Organization recommendations. A 3-stage "roll-out package" has been developed for effectively integrating and scaling up such programs to full-national scale. Stage-1 lays the groundwork-identifying NTD leadership within the Ministry of Health, conducting a national Situation Analysis, formulating a multiyear Plan of Action, and undertaking a funding gap analysis. Stage-2 focuses on scaling up the integrated NTD program-convening national stakeholder meetings, developing annual work plans, carrying out disease mapping, and establishing monitoring and evaluation activities. Stage-3 aims at ensuring effective management-identifying clear roles and responsibilities for partners, and creating a central coordinating mechanism. Assessment and reassessment of these complex NTD programs that target literally billions of people are essential to establish "best practice" strategies for long-term public health success.

Assessment of the anthelmintic efficacy of albendazole in school children in seven countries where soil-transmitted helminths are endemic

Background

The three major soil-transmitted helminths (STH) Ascaris lumbricoides, Trichuris trichiura and Necator americanus/Ancylostoma duodenale are among the most widespread parasites worldwide. Despite the global expansion of preventive anthelmintic treatment, standard operating procedures to monitor anthelmintic drug efficacy are lacking. The objective of this study, therefore, was to define the efficacy of a single 400 milligram dose of albendazole (ALB) against these three STH using a standardized protocol.

Methodology/Principal Findings

Seven trials were undertaken among school children in Brazil, Cameroon, Cambodia, Ethiopia, India, Tanzania and Vietnam. Efficacy was assessed by the Cure Rate (CR) and the Fecal Egg Count Reduction (FECR) using the McMaster egg counting technique to determine fecal egg counts (FEC). Overall, the highest CRs were observed for A. lumbricoides (98.2%) followed by hookworms (87.8%) and T. trichiura (46.6%). There was considerable variation in the CR for the three parasites across trials (country), by age or the pre-intervention FEC (pre-treatment). The latter is probably the most important as it had a considerable effect on the CR of all three STH. Therapeutic efficacies, as reflected by the FECRs, were very high for A. lumbricoides (99.5%) and hookworms (94.8%) but significantly lower for T. trichiura (50.8%), and were affected to different extents among the 3 species by the pre-intervention FEC counts and trial (country), but not by sex or age.

Conclusions/Significance

Our findings suggest that a FECR (based on arithmetic means) of >95% for A. lumbricoides and >90% for hookworms should be the expected minimum in all future surveys, and that therapeutic efficacy below this level following a single dose of ALB should be viewed with concern in light of potential drug resistance. A standard threshold for efficacy against T. trichiura has yet to be established, as a single-dose of ALB is unlikely to be satisfactory for this parasite.

Trial Registration

ClinicalTrials.gov NCT01087099

Soil-transmitted helminths (roundworms, whipworms and hookworms) infect millions of children in (sub)tropical countries, resulting in malnutrition, growth stunting, intellectual retardation and cognitive deficits. Currently, there is a need to closely monitor anthelmintic drug efficacy and to develop standard operating procedures, as highlighted in a World Health Organization–World Bank meeting on “Monitoring of Drug Efficacy in Large Scale Treatment Programs for Human Helminthiasis” in Washington DC at the end of 2007. Therefore, we have evaluated the efficacy of a commonly used treatment against these parasitic infections in school children in Africa, Asia and South-America using a standardized protocol. In addition, different statistical approaches to analyzing the data were evaluated in order to develop standardized procedures for data analysis. The results demonstrate that the applied treatment was highly efficacious against round- and hookworms, but not against whipworms. However, there was large variation in efficacy across the different trials which warrants further attention. This study also provides new insights into the statistical analysis of efficacy data, which should be considered in future monitoring and evaluation studies of large scale anthelmintic treatment programs. Finally, our findings emphasize the need to update the World Health Organization recommended efficacy threshold for the treatment of STH.

Moderate and high endemicity of schistosomiasis is a predictor of the endemicity of soil-transmitted helminthiasis: a systematic review

The authors conducted a systematic literature review with the following aims: to investigate how frequently soil-transmitted helminthiasis (STH) infections are endemic where schistosomiasis is present; and to assess the correlation between the risk level of schistosomiasis and that of STH. Among 155 sites on which data were collected and analyzed, schistosomiasis was present in 130, all of which were also co-endemic for STH, whereas 25 sites were endemic only for STH. Ninety percent (117 out of 130) of the areas eligible for preventive chemotherapy (PC) against schistosomiasis are also eligible for PC against STH. This fact provides managers of control programmes with the operationally important indication that use of available information on endemicity of schistosomiasis is a valid tool to predict the presence of STH in the same geographical area and to estimate the need of PC for STH. The implementation of this tool is expected to save financial and human resources and help accelerate the scale-up of PC throughout the world.

Controlling soil-transmitted helminthiasis in pre-school-age children through preventive chemotherapy

Pre-school age children account for 10%–20% of the 2 billion people worldwide who are infected with soil-transmitted helminths (STHs): Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm), and Ancylostoma duodenale/Necator americanus (hookworms). Through a systematic review of the published literature and using information collated at World Health Organization headquarters, this paper summarizes the available evidence to support the recommendation that pre-school children should be included in regular deworming programmes. The first section describes the burden of STH disease in this age group, followed by a summary of how infection impacts iron status, growth, vitamin A status, and cognitive development and how STHs may exacerbate other high mortality infections. The second section explores the safety of the drugs themselves, given alone or co-administered, drug efficacy, and the importance of safe administration. The third section provides country-based evidence to demonstrate improved health outcomes after STH treatment. The final section provides country experiences in scaling up coverage of pre-school children by using other large scale public health interventions, including vitamin A programmes, immunization campaigns, and Child Health days. The paper concludes with a number of open research questions and a summary of some of the operational challenges that still need to be addressed.

The Global Burden of Disease assessments--WHO is responsible?

The Global Burden of Disease (GBD) concept has been used by the World Health Organization (WHO) for its reporting on health information for nearly 10 years. The GBD approach results in a single summary measure of morbidity, disability, and mortality, the so-called disability-adjusted life year (DALY). To ensure transparency and objectivity in the derivation of health information, WHO has been urged to use reference groups of external experts to estimate burden of disease. Under the leadership and coordination of WHO, expert groups have been appraising and abstracting burden of disease information. Examples include the Child Health Epidemiology Reference Group (CHERG), the Malaria Monitoring and Evaluation Reference Group (MERG), and the recently established Foodborne Disease Burden Epidemiology Reference Group (FERG). The structure and functioning of and lessons learnt by these groups are described in this paper. External WHO expert groups have provided independent scientific health information while operating under considerable differences in structure and functioning. Although it is not appropriate to devise a single "best practice" model, the common thread described by all groups is the necessity of WHO's leadership and coordination to ensure the provision and dissemination of health information that is to be globally accepted and valued.

Control of Taenia solium cysticercosis/taeniosis

Cysticercosis is emerging as a serious public health and agricultural problem in many poorer countries of Latin America, Africa, and Asia. Caused by the pork tapeworm, Taenia solium, this zoonotic disease forms larval cysts in humans and pigs that can lead to epilepsy and death in humans, reduces the market value of pigs and makes pork unsafe to eat. It occurs where pigs range freely, sanitation is poor, and meat inspection is absent or inadequate, and is thus strongly associated with poverty and smallholder farming. Although theoretically easy to control and declared eradicable cysticercosis remains neglected in most endemic countries due to lack of information and awareness about the extent of the problem, suitable diagnostic and management capacity, and appropriate prevention and control strategies. Human neurocysticercosis occurs when the larval cysts develop in the brain. It is considered to be the most common parasitic infection of the human nervous system and the most frequent preventable cause of epilepsy in the developing world. Thus far the infection has not been eliminated from any region by a specific program, and no national control programs are yet in place. We consider the tools available for combating cysticercosis and suggest simple packages of interventions, which can be conducted utilizing existing services and structures in the endemic countries to provide appropriate and sustainable control of the disease.

An analysis of the impact of the Schistosomiasis Control Programme in Brazil

The impact of the Schistosomiasis Control Programme (PCE) in Brazil was analyzed, covering the period 1976 to 2003, using the following indicators: percentage of Schistosoma mansoni carriers detected among the population examined in the coproscopic surveys (PPS): mortality rate for schistosomiasis, per 100,000 inhabitants (TME): hospitalization rate for schistosomiasis, per 100,000 inhabitants (TIE): average age of deaths caused by schistosomiasis (IMOE). There was a 38.5% reduction in the PPS after the introduction of the PCE, attributed to the treatment of carriers. Even in hyper-endemic municipalities, such as Conde and Cuitegí, in the state of Paraíba, the PPS fell more than 50% after the first year of treatment. The parasitic burden of the carriers also decreased in the two municipalities. The TME was reduced by 63.4% and the TIE by 77.3%. The mortality rate was highest among the 50-and-above age group. The country's IMOE rose 32.3%. The IMOE was seen to be much lower in the state of Minas Gerais, where the PCE was only initiated in 1983, with very limited coverage.

Reconsidering the underestimated burden caused by neglected tropical diseases

It is generally acknowledged that the burden caused by neglected tropical diseases needs to be reassessed. Not only are there several important diseases unaccounted for, but new information suggests they have a more substantial impact on health than initially thought. Looking at the tropical diseases as a group makes sense: they tend to cluster in the same poor populations and, to make progress with their control, they will have to be dealt with in an integrated manner. Measuring the effect of such integrated control is likely to reveal the real impact of tropical diseases on human health and wellbeing.