Fiona M. Fleming

Impact of a national helminth control programme on infection and morbidity in Ugandan schoolchildren

OBJECTIVE We aimed to assess the health impact of a national control programme targeting schistosomiasis and intestinal nematodes in Uganda, which has provided population-based anthelmintic chemotherapy since 2003. METHODS We conducted longitudinal surveys on infection status, haemoglobin concentration and clinical morbidity in 1871 randomly selected schoolchildren from 37 schools in eight districts across Uganda at three time points - before chemotherapy and after one year and two years of annual mass chemotherapy. FINDINGS Mass treatment with praziquantel and albendazole led to a significant decrease in the intensity of Schistosoma mansoni - 70% (95% confidence interval (CI): 66-73%) after one year and 82% (95% CI: 80-85%) after two years of treatment. Intensity of hookworm infection also decreased (75% and 93%; unadjusted). There was a significant increase in haemoglobin concentration after one (0.135 g/dL (95% CI: 0.126-0.144)) and two years (0.303 g/dL (95% CI: 0.293-0.312)) of treatment, and a significant decrease in signs of early clinical morbidity. The impact of intervention on S. mansoni prevalence and intensity was similar to that predicted by mathematical models of the impact of chemotherapy on human schistosomiasis. Improvements in haemoglobin concentration were greatest among children who were anaemic or harbouring heavy S. mansoni infection at baseline. CONCLUSION Anthelmintic treatment delivered as part of a national helminth control programme can decrease infection and morbidity among schoolchildren and improve haemoglobin concentration.

Synergistic associations between hookworm and other helminth species in a rural community in Brazil

Objective  To identify possible synergistic associations of hookworm and other helminths.

Age patterns in undernutrition and helminth infection in a rural area of Brazil: associations with ascariasis and hookworm

Objective  To investigate the nutritional status of individuals from a rural area of Brazil, and associations with helminth infections in an age‐stratified sample.

Parasitological impact of 2-year preventive chemotherapy on schistosomiasis and soil-transmitted helminthiasis in Uganda

BackgroundSchistosomiasis and soil-transmitted helminthiasis (STH) are among the neglected tropical diseases in Africa. A national control program for these diseases was initiated in Uganda during March 2003. Annual treatment with praziquantel and albendazole was given to schoolchildren in endemic areas and to adults in selected communities where local prevalence of Schistosoma mansoni in schoolchildren was high.MethodsThe impact of the treatment program was monitored through cohorts of schoolchildren and adults. Their infection status with S. mansoni and STH was determined by parasitological examinations at baseline and at annual follow-ups. The prevalence and intensity of S. mansoni and STH before and after treatment were analyzed.ResultsTwo rounds of treatment significantly reduced the prevalence of S. mansoni infection in schoolchildren across three regions in the country from 33.4–49.3% to 9.7–29.6%, and intensity of infection from 105.7–386.8 eggs per gram of faeces (epg) to 11.6–84.1 epg. The prevalence of hookworm infection was reduced from 41.2–57.9% to 5.5–16.1%, and intensity of infection from 186.9–416.8 epg to 3.7–36.9 epg. The proportion of children with heavy S. mansoni infection was significantly reduced from 15% (95% CI 13.4–16.8%) to 2.3% (95% CI 1.6–3.0%). In adults, significant reduction in the prevalence and intensity of S. mansoni and hookworm infections was also observed. More importantly, the prevalence and intensity of both S. mansoni and hookworm infections in the cohorts of newly-recruited 6-year-olds who had never previously received treatment decreased significantly over 2 years: 34.9% (95% CI 31.9–37.8%) to 22.6% (95% CI 19.9–25.2%) and 171.1 epg (95% CI 141.5–200.7) to 72.0 epg (95% CI 50.9–93.1) for S. mansoni; and 48.4% (95% CI 45.4–51.5) to 15.9% (95% CI 13.6–18.2) and 232.7 epg (95% CI 188.4–276.9) to 51.4 epg (95% CI 33.4–69.5) for hookworms, suggesting a general decline in environmental transmission levels.ConclusionAnnual anthelminthic treatment delivered to schoolchildren and to adults at high risk in Uganda can significantly reduce the prevalence and intensity of infection for schistosomiasis and STH, and potentially also significantly reduce levels of environmental transmission of infection.

Mapping, monitoring, and surveillance of neglected tropical diseases: towards a policy framework

As national programmes respond to the new opportunities presented for scaling up preventive chemotherapy programmes for the coadministration of drugs to target lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiasis, and trachoma, possible synergies between existing disease-specific policies and protocols need to be examined. In this report we compare present policies for mapping, monitoring, and surveillance for these diseases, drawing attention to both the challenges and opportunities for integration. Although full integration of all elements of mapping, monitoring, and surveillance strategies might not be feasible for the diseases targeted through the preventive chemotherapy approach, there are opportunities for integration, and we present examples of integrated strategies. Finally, if advantage is to be taken of scaled up interventions to address neglected tropical diseases, efforts to develop rapid, inexpensive, and easy-to-use methods, whether disease-specific or integrated, should be increased. We present a framework for development of an integrated monitoring and evaluation system that combines both integrated and disease-specific strategies.

Process evaluation of schistosomiasis control in Uganda, 2003 to 2006: perceptions, attitudes and constraints of a national programme.

Schistosomiasis is widespread in Uganda along large lakes and rivers with approximately 4 million people infected. Hookworm infections also prevalent throughout the country, while infections with Ascaris lumbricoides and Trichuris trichiura are mainly found in south-western Uganda. A national programme aimed at controlling morbidity due to these infections was launched in 2003. This article describes the perceptions, attitudes, constraints and experiences of those implementing the programme and those receiving the treatment. The study used qualitative data collected largely in two districts but also from 18 other districts implementing the programme. Results showed that mass treatment was perceived to be beneficial because the drugs make people feel better. However, side-effects of praziquantel (PZQ), the smell and size of the tablets and the use of height, not weight, to determine dose were raised as major factors discouraging people from taking the drug. Generally, most of the end-users were appreciative of the programme and were beginning to demand regular treatment. Nevertheless, intensive and sustained health education is still vital for improvement of treatment coverage, especially among the non-compliers. It was repeatedly highlighted that there is a need to stock PZQ in all health facilities in endemic areas. Provision of incentives to drug distributors and to involve as many stakeholders as possible in the planning phase were also raised by respondents. Lessons learned for the development and success of a helminth control programme at a national scale are discussed.

Integrated prevalence mapping of schistosomiasis, soil-transmitted helminthiasis and malaria in lakeside and island communities in Lake Victoria, Uganda

BackgroundIt is widely advocated that integrated strategies for the control of neglected tropical diseases (NTDs) are cost-effective in comparison to vertical disease-specific programmes. A prerequisite for implementation of control interventions is the availability of baseline data of prevalence, including the population at risk and disease overlap. Despite extensive literature on the distribution of schistosomiasis on the mainland in Uganda, there has been a knowledge gap for the prevalence of co-infections with malaria, particularly for island communities in Lake Victoria. In this study, nine lakeshore and island districts were surveyed for the prevalence of NTDs and malaria, as well as educational and health infrastructure.ResultsA total of 203 communities were surveyed, including over 5000 school-age children. Varying levels of existing health infrastructure were observed between districts, with only Jinja District regularly treating people for NTDs. Community medicine distributors (CMD) were identified and trained in drug delivery to strengthen capacity. Prevalence levels of intestinal schistosomiasis and soil-transmitted helminthiasis were assessed via Kato-Katz thick smears of stool and malaria prevalence determined by microscopy of fingerprick blood samples. Prevalence levels were 40.8%, 26.04% and 46.4%, respectively, while the prevalence of co-infection by Schistosoma mansoni and Plasmodium spp. was 23.5%. Socio-economic status was strongly associated as a risk factor for positive infection status with one or more of these diseases.ConclusionsThese results emphasise the challenges of providing wide-scale coverage of health infrastructure and drug distribution in remote lakeshore communities. The data further indicate that co-infections with malaria and NTDs are common, implying that integrated interventions for NTDs and malaria are likely to maximize cost-effectiveness and sustainability of disease control efforts.

Cost-effectiveness of scaling up mass drug administration for the control of soil-transmitted helminths: a comparison of cost function and constant costs analyses

BACKGROUND The coverage of mass drug administration (MDA) for neglected tropical diseases, such as the soil-transmitted helminths (STHs), needs to rapidly expand to meet WHOs 2020 targets. We aimed to compare use of a cost function to take into account economies of scale to the standard method of assuming a constant cost per treatment when investigating the cost and cost-effectiveness of scaling up a STH MDA programme targeting Ascaris lumbricoides. METHODS We fitted a cost function describing how the costs of MDA change with scale to empirical cost data and incorporated it into a STH transmission model. Using this cost function, we investigated the consequences of taking into account economies of scale on the projected cost-effectiveness of STH control, by comparison with the standard method of assuming a constant cost per treatment. The cost function was fitted to economic cost data collected as part of a school-based deworming programme in Uganda using maximum likelihood methods. We used the model to investigate the total reduction in the overall worm burden, the total number of prevalent infection case-years averted, and the total number of heavy infection case-years averted. For each year, we calculated the effectiveness as the difference between the worm burden or number of cases and the number in absence of treatment. FINDINGS When using the cost function, the cost-effectiveness of STH control markedly increased as the programme was scaled up. By contrast, the standard method (constant cost per treatment) undervalued this and generated misleading conclusions. For example, when scaling up control in the projected district from 10% to 75% coverage of at-risk school-age children, the cost-effectiveness in terms of prevention of heavy burden infections was projected to increase by over 70% when using the cost function, but decrease by 18% when assuming a constant cost per treatment. INTERPRETATION The current exclusion of economies of scale in most economic analyses must be addressed if the most cost-effective policies for the control of neglected tropical diseases are to be formulated. These findings are also relevant to other large-scale disease interventions. FUNDING GlaxoSmithKline, Bill & Melinda Gates Foundation, Partnership for Child Development, and Wellcome Trust.

Economic Considerations for Moving beyond the Kato-Katz Technique for Diagnosing Intestinal Parasites As We Move Towards Elimination

While the need for more sensitive diagnostics for intestinal helminths is well known, the cost of developing and implementing new tests is considered relatively high compared to the Kato-Katz technique. Here, we review the reported costs of performing the Kato-Katz technique. We also outline several economic arguments we believe highlight the need for further investment in alternative diagnostics, and considerations that should be made when comparing their costs. In our opinion, we highlight that, without new diagnostic methods, it will be difficult for policy makers to make the most cost-effective decisions and that the potentially higher unit costs of new methods can be outweighed by the long-term programmatic benefits they have (such as the ability to detect the interruption of transmission).

Neglected tropical diseases: comparison of the costs of integrated and vertical preventive chemotherapy treatment in Niger

BACKGROUND This study presents evidence on the cost of integrated preventive chemotherapy treatment (PCT) to control trachoma, schistosomiasis, lymphatic filariasis and soil-transmitted helminthiasis (STH) in Niger. Integrated PCT costs are compared with the costs of vertical PCT control. METHODS Data were analysed for the integrated PCT of 2008 and 2009 in six districts. Receipts, treatment registers, coverage forms and drug registers provided cost and treatment information. Economic costs of the time spent on campaign activities by government staff was derived from a survey of 56 staff. Integrated control costs were compared with vertical programmes undertaken in 2005 using 2009 constant prices. RESULTS The average economic cost of integrated PCT was US