Reducing the Antigen Prevalence Target Threshold for Stopping and Restarting Mass Drug Administration for Lymphatic Filariasis Elimination: A Model-Based Cost-effectiveness Simulation in Tanzania, India and Haiti.

BACKGROUND: The Global Programme to Eliminate Lymphatic Filariasis (GPELF) aims to reduce and maintain infection levels through mass drug administration (MDA), but there is evidence of ongoing transmission after MDA in areas where Culex mosquitoes are the main transmission vector, suggesting that a more stringent criterion is required for MDA decision making in these settings. METHODS: We use a transmission model to investigate how a lower prevalence threshold (<1% antigenemia [Ag] prevalence compared with <2% Ag prevalence) for MDA decision making would affect the probability of local elimination, health outcomes, the number of MDA rounds, including restarts, and program costs associated with MDA and surveys across different scenarios. To determine the cost-effectiveness of switching to a lower threshold, we simulated 65% and 80% MDA coverage of the total population for different willingness to pay per disability-adjusted life-year averted for India ($446.07), Tanzania ($389.83), and Haiti ($219.84). RESULTS: Our results suggest that with a lower Ag threshold, there is a small proportion of simulations where extra rounds are required to reach the target, but this also reduces the need to restart MDA later in the program. For 80% coverage, the lower threshold is cost-effective across all baseline prevalences for India, Tanzania, and Haiti. For 65% MDA coverage, the lower threshold is not cost-effective due to additional MDA rounds, although it increases the probability of local elimination. Valuing the benefits of elimination to align with the GPELF goals, we find that a willingness to pay per capita government expenditure of approximately $1000-$4000 for 1% increase in the probability of local elimination would be required to make a lower threshold cost-effective. CONCLUSIONS: Lower Ag thresholds for stopping MDAs generally mean a higher probability of local elimination, reducing long-term costs and health impacts. However, they may also lead to an increased number of MDA rounds required to reach the lower threshold and, therefore, increased short-term costs. Collectively, our analyses highlight that lower target Ag thresholds have the potential to assist programs in achieving lymphatic filariasis goals.

Economic performance and cost-effectiveness of using a DEC-salt social enterprise for eliminating the major neglected tropical disease, lymphatic filariasis.

BACKGROUND: Salt fortified with the drug, diethylcarbamazine (DEC), and introduced into a competitive market has the potential to overcome the obstacles associated with tablet-based Lymphatic Filariasis (LF) elimination programs. Questions remain, however, regarding the economic viability, production capacity, and effectiveness of this strategy as a sustainable means to bring about LF elimination in resource poor settings. METHODOLOGY AND PRINCIPAL FINDINGS: We evaluated the performance and effectiveness of a novel social enterprise-based approach developed and tested in Léogâne, Haiti, as a strategy to sustainably and cost-efficiently distribute DEC-medicated salt into a competitive market at quantities sufficient to bring about the elimination of LF. We undertook a cost-revenue analysis to evaluate the production capability and financial feasibility of the developed DEC salt social enterprise, and a modeling study centered on applying a dynamic mathematical model localized to reflect local LF transmission dynamics to evaluate the cost-effectiveness of using this intervention versus standard annual Mass Drug Administration (MDA) for eliminating LF in Léogâne. We show that the salt enterprise because of its mixed product business strategy may have already reached the production capacity for delivering sufficient quantities of edible DEC-medicated salt to bring about LF transmission in the Léogâne study setting. Due to increasing revenues obtained from the sale of DEC salt over time, expansion of its delivery in the population, and greater cumulative impact on the survival of worms leading to shorter timelines to extinction, this strategy could also represent a significantly more cost-effective option than annual DEC tablet-based MDA for accomplishing LF elimination. SIGNIFICANCE: A social enterprise approach can offer an innovative market-based strategy by which edible salt fortified with DEC could be distributed to communities both on a financially sustainable basis and at sufficient quantity to eliminate LF. Deployment of similarly fashioned intervention strategies would improve current efforts to successfully accomplish the goal of LF elimination, particularly in difficult-to-control settings.

Audit of the community-directed treatment with ivermectin (CDTI) for onchocerciasis and factors associated with adherence in three regions of Cameroon.

BACKGROUND: After more than 15 years of community-directed treatment with ivermectin (CDTI) in the Centre 1, Littoral 2 and West CDTI projects in Cameroon, the epidemiological evaluation conducted in 2011 revealed that onchocerciasis endemicity was still high in some communities. To investigate the potential reasons explaining this high endemicity, a cluster coverage survey was conducted in April-May 2015 in three health districts (HD), to assess the implementation of the CDTI, the 2014 therapeutic coverage and the five-year adherence to treatment. A two-stage cluster design was considered during analyses, with data weighted proportionally to age and gender distribution in the population. RESULTS: In the three HDs, 69 community leaders, 762 heads of households, 83 community drug distributors (CDD) and 2942 household members were interviewed. The CDTI organization and the involvement of heads of households were in average weak, with 84.0% (95% CI: 81.2-86.4%) of them who had not participated in activities during the 2014 mass drug administration (MDA). On average, six of ten community leaders declared that the period of treatment was decided by the health personnel while the CDDs selection was made during a community meeting for only 43.4% of them. The 2014 weighted therapeutic coverage was 64.1% (95% CI: 56.8-70.9%), with no significant difference in the three HDs. The survey coverages were lower than the reported coverages with a significant difference varying from 14.1% to 22.0%. Among those aged 10 years and above, 57.8% (95% CI: 50.2-65.1%) declared having taken the treatment each time during the last five MDAs with no significant difference among HDs, while 9.8% (95% CI: 7.5-12.8%) declared that they had never taken the drug. In multivariate analysis, the most important factors associated with the five-year adherence to treatment were high involvement in CDTI and age (40+ years). CONCLUSIONS: Despite more than 15 years of CDTI, there was still weak community participation and ownership, a lower coverage than reported and an average five-year adherence in the surveyed HDs. The reinforcement of the community ownership by the Ministry of Public Health officials and the timely procurement of ivermectin as requested by the communities are some measures that should be implemented to improve the therapeutic coverage, adherence to treatment and hence achieve onchocerciasis elimination. Further anthropological and entomological studies would provide better insights into our understanding of the persistence of the disease in these three CDTI projects.

Evaluation of Treatment Coverage and Enhanced Mass Drug Administration for Onchocerciasis and Lymphatic Filariasis in Five Local Government Areas Treating Twice Per Year in Edo State, Nigeria.

The western region of Edo state in southern Nigeria is highly endemic for onchocerciasis. Despite years of mass drug administration (MDA) with ivermectin (IVM), reports suggest persistently high prevalence of onchocerciasis, presumably because of poor coverage. In 2016, twice-per-year treatment with IVM (combined with albendazole for lymphatic filariasis in the first round where needed) began in five local government areas (LGAs) of Edo state. We undertook a multistage cluster survey within 3 months after each round of MDA to assess coverage. First-round coverage was poor: among 4,942 people of all ages interviewed from 145 clusters, coverage was 31.1% (95% confidence intervals [CI]: 24.1-38.0%). Most respondents were not offered medicines. To improve coverage in the second round, three LGAs were randomized to receive MDA through a "modified campaign" approach focused on improved supervision and monitoring. The other two LGAs continued with standard MDA as before. A similar survey was conducted after the second round, interviewing 3,362 people in 87 clusters across the five LGAs. Coverage was not statistically different from the first round (40.0% [95% CI: 31.0-49.0%]) and there was no significant difference between the groups (P = 0.7), although the standard MDA group showed improvement over round 1 (P < 0.01). The additional cost per treatment in the modified MDA was 1.6 times that of standard MDA. Compliance was excellent among those offered treatment. We concluded that poor mobilization, medicine distribution, and program penetration led to low coverage. These must be addressed to improve treatment coverage in Edo state.

Economic evaluations of lymphatic filariasis interventions: a systematic review and research needs.

In 2000, the World Health Organization established the Global Programme to Eliminate Lymphatic Filariasis (GPELF), with the goal of eliminating the disease as a public health problem by 2020. Since the start of the programme, a cumulative total of 6.2 billion treatments have been delivered to affected populations - with more than 556 million people treated in 2015 alone. In this paper, we perform a rigorous systematic review of the economic evaluations of lymphatic filariasis interventions have been conducted. We demonstrate that the standard interventions to control lymphatic filariasis are consistently found to be highly cost-effective. This finding has important implications for advocacy groups and potential funders. However, there are several important inconsistencies and research gaps that need to be addressed as we move forward towards the 2020 elimination goals. One of the most important identified research gaps was a lack of evaluation of new interventions specifically targeting areas co-endemic with onchocerciasis and Loa loa - which could become a major barrier to achieving elimination.

How much will it cost to eradicate lymphatic filariasis? An analysis of the financial and economic costs of intensified efforts against lymphatic filariasis.

INTRODUCTION: Lymphatic filariasis (LF), a neglected tropical disease (NTD) preventable through mass drug administration (MDA), is one of six diseases deemed possibly eradicable. Previously we developed one LF elimination scenario, which assumes MDA scale-up to continue in all countries that have previously undertaken MDA. In contrast, our three previously developed eradication scenarios assume all LF endemic countries will undertake MDA at an average (eradication I), fast (eradication II), or instantaneous (eradication III) rate of scale-up. In this analysis we use a micro-costing model to project the financial and economic costs of each of these scenarios in order to provide evidence to decision makers about the investment required to eliminate and eradicate LF. METHODOLOGY/KEY FINDINGS: Costing was undertaken from a health system perspective, with all results expressed in 2012 US dollars (USD). A discount rate of 3% was applied to calculate the net present value of future costs. Prospective NTD budgets from LF endemic countries were reviewed to preliminarily determine activities and resources necessary to undertake a program to eliminate LF at a country level. In consultation with LF program experts, activities and resources were further reviewed and a refined list of activities and necessary resources, along with their associated quantities and costs, were determined and grouped into the following activities: advocacy and communication, capacity strengthening, coordination and strengthening partnerships, data management, ongoing surveillance, monitoring and supervision, drug delivery, and administration. The costs of mapping and undertaking transmission assessment surveys and the value of donated drugs and volunteer time were also accounted for. Using previously developed scenarios and deterministic estimates of MDA duration, the financial and economic costs of interrupting LF transmission under varying rates of MDA scale-up were then modelled using a micro-costing approach. The elimination scenario, which includes countries that previously undertook MDA, is estimated to cost 929 million USD (95% Credible Interval: 884m-972m). Proceeding to eradication is anticipated to require a higher financial investment, estimated at 1.24 billion USD (1.17bn-1.30bn) in the eradication III scenario (immediate scale-up), with eradication II (intensified scale-up) projected at 1.27 billion USD (1.21bn-1.33bn), and eradication I (slow scale-up) estimated at 1.29 billion USD (1.23bn-1.34bn). The economic costs of the eradication III scenario are estimated at approximately 7.57 billion USD (7.12bn-7.94bn), while the elimination scenario is projected to have an economic cost of 5.21 billion USD (4.91bn-5.45bn). Countries in the AFRO region will require the greatest investment to reach elimination or eradication, but also stand to gain the most in cost savings. Across all scenarios, capacity strengthening and advocacy and communication represent the greatest financial costs, whereas mapping, post-MDA surveillance, and administration comprise the least. CONCLUSIONS/SIGNIFICANCE: Though challenging to implement, our results indicate that financial and economic savings are greatest under the eradication III scenario. Thus, if eradication for LF is the objective, accelerated scale-up is projected to be the best investment.

Doing well while fighting river blindness: the alignment of a corporate drug donation programme with responsibilities to shareholders.

OBJECTIVE: Using the example of Merck's donations of ivermectin, to show how tax incentives and non-profit collaborators can make corporate largesse consistent with obligations to maximise returns to shareholders. METHODS: We obtained information from publicly available data and estimated Merck's tax deductions according to the US Internal Revenue Code. Reviews of Merck-Kitasato contracts and personal interviews provided additional information regarding key lessons from this collaboration. RESULTS: Our best estimate of the direct cost to Merck of the ivermectin tablets donated during 2005-2011 is around US$ 600 million, well below the stated value of US$ 3.8 billion. Our calculation of tax write-offs reduces the net cost to around US$ 180 million in that period. Indirect market benefits and effects on goodwill further enhanced the compatibility of Merck's donation programme with the company's profit-maximising objective. The case offers lessons for effective management of collaborations with public and non-profit organisations. CONCLUSION: Merck's role in the donation of ivermectin for the treatment of onchocerciasis is widely and justly acknowledged as a prime example of corporate largesse in the public interest. It is nevertheless important to note that several public and non-profit collaborators, and United States taxpayers, played significant roles in increasing Merck's incentives, and indeed ability, to conduct the donation programme that changed so many lives in poor countries, while meeting its responsibilities to shareholders. Overall, the record indicates responsible corporate management of Merck's ivermectin programme and demonstrates the feasibility of socially responsible policies in a manner compatible with obligations to shareholders.

Financial and Economic Costs of the Elimination and Eradication of Onchocerciasis (River Blindness) in Africa.

BACKGROUND: Onchocerciasis (river blindness) is a parasitic disease transmitted by blackflies. Symptoms include severe itching, skin lesions, and vision impairment including blindness. More than 99% of all cases are concentrated in sub-Saharan Africa. Fortunately, vector control and community-directed treatment with ivermectin have significantly decreased morbidity, and the treatment goal is shifting from control to elimination in Africa. METHODS: We estimated financial resources and societal opportunity costs associated with scaling up community-directed treatment with ivermectin and implementing surveillance and response systems in endemic African regions for alternative treatment goals--control, elimination, and eradication. We used a micro-costing approach that allows adjustment for time-variant resource utilization and for the heterogeneity in the demographic, epidemiological, and political situation. RESULTS: The elimination and eradication scenarios, which include scaling up treatments to hypo-endemic and operationally challenging areas at the latest by 2021 and implementing intensive surveillance, would allow savings of $1.5 billion and $1.6 billion over 2013-2045 as compared to the control scenario. Although the elimination and eradication scenarios would require higher surveillance costs ($215 million and $242 million) than the control scenario ($47 million), intensive surveillance would enable treatments to be safely stopped earlier, thereby saving unnecessary costs for prolonged treatments as in the control scenario lacking such surveillance and response systems. CONCLUSIONS: The elimination and eradication of onchocerciasis are predicted to allow substantial cost-savings in the long run. To realize cost-savings, policymakers should keep empowering community volunteers, and pharmaceutical companies would need to continue drug donation. To sustain high surveillance costs required for elimination and eradication, endemic countries would need to enhance their domestic funding capacity. Societal and political will would be critical to sustaining all of these efforts in the long term.

African Programme For Onchocerciasis Control 1995-2015: model-estimated health impact and cost.

BACKGROUND: Onchocerciasis causes a considerable disease burden in Africa, mainly through skin and eye disease. Since 1995, the African Programme for Onchocerciasis Control (APOC) has coordinated annual mass treatment with ivermectin in 16 countries. In this study, we estimate the health impact of APOC and the associated costs from a program perspective up to 2010 and provide expected trends up to 2015. METHODS AND FINDINGS: With data on pre-control prevalence of infection and population coverage of mass treatment, we simulated trends in infection, blindness, visual impairment, and severe itch using the micro-simulation model ONCHOSIM, and estimated disability-adjusted life years (DALYs) lost due to onchocerciasis. We assessed financial costs for APOC, beneficiary governments, and non-governmental development organizations, excluding cost of donated drugs. We estimated that between 1995 and 2010, mass treatment with ivermectin averted 8.2 million DALYs due to onchocerciasis in APOC areas, at a nominal cost of about US$257 million. We expect that APOC will avert another 9.2 million DALYs between 2011 and 2015, at a nominal cost of US$221 million. CONCLUSIONS: Our simulations suggest that APOC has had a remarkable impact on population health in Africa between 1995 and 2010. This health impact is predicted to double during the subsequent five years of the program, through to 2015. APOC is a highly cost-effective public health program. Given the anticipated elimination of onchocerciasis from some APOC areas, we expect even more health gains and a more favorable cost-effectiveness of mass treatment with ivermectin in the near future.

Challenges for the integration of mass drug administrations against multiple 'neglected tropical diseases'.

Simple and safe medications for some of the common, but often neglected, diseases that afflict the poor are not only available but are often donated. Other medications indicated for neglected diseases are extremely cheap and cost-effective. These drugs can be administered together and combined, when feasible, into rapid-intervention packages based on mass drug administrations. It is therefore logical to integrate mass drug administrations when possible. Integration is, however, not always as simple as it seems, and 'integration' means different things to different people. Drugs are needed at different frequencies for different lengths of time, sometimes for the whole population, sometimes only for children. Care has to be taken that parallel systems are not created that bypass primary healthcare. Much can be achieved, however, by sensible integration, whether it be in the mapping of diseases or the setting up of treatment platforms that tackle several diseases at once. As governments and international organizations seek to create policies for integration that include not only mass drug administration but also morbidity control, and as various partnerships develop for implementation, there is the possibility to scale up health interventions, which will have a very positive impact on the poorest communities globally. Nevertheless, integration should not be forced for the sake of policy. Where things fit well they should be developed, where not, coordination within the primary-healthcare system can produce an equally long-lasting impact.

Lymphatic filariasis: patients and the global elimination programme.

The defining images of lymphatic filariasis are the horrendous disfigurements of lymphoedema, elephantiasis and hydrocele. These clinical presentations, although obviously important and life changing, are not, however, the only outcomes of this wide-spread filarial infection. The other effects of the disease range from severe, acute but short-term bouts of sickness to psychological impairment, poverty and family hardship. It is important to support cases of the disease through all means available, such as reparative hydrocelectomy, hygiene training and facilitation, and the provision of adequate chemotherapy. Although only a minority of the residents in any endemic community is affected with the severe clinical manifestations of this parasitic infection, these cases are central to, and important advocates for, the current global effort to eliminate the infection through mass drug administrations (MDA). Their clinical improvement acts as an important catalyst for the general population and encourages high compliance in the MDA. This communication discusses the central role that filariasis patients have played in the Tanzania Lymphatic Filariasis Elimination Programme to date, and covers some of the clinical successes achieved in the past 10 years. The abolition of the clinical manifestations of filarial infection remains the ultimate goal of the Global Programme to Eliminate Lymphatic Filariasis, and maintaining a focus on the affected individuals and their clinical condition is vital to that programme's overall success.

The World Bank.

The control of human onchocerciasis (river blindness) is one of the most successful global partnerships ever supported by the World Bank. Mectizan mass treatments have greatly contributed to this success and have shaped the strategies of the programmes in which the World Bank has been involved - the Onchocerciasis Control Programme (OCP), which covered onchocerciasis control in West Africa until 2002, and the African Programme for Onchocerciasis Control (APOC), which is currently working in 30 countries, to protect millions of people from onchocerciasis. Through the strategy of community-directed treatment with ivermectin (CDTI), onchocerciasis control in Africa was transformed from a technologically-driven and vertical health initiative to a community-directed process of treatment and empowerment. Together, CDTI and the donation of Mectizan also reduced costs, producing one of the most effective and affordable disease-control schemes ever seen, and the CDTI strategy is now being applied to other disease-control initiatives. The onchocerciasis programmes have also been exemplary in shaping partnerships with communities, countries, the World Health Organization, governments, non-governmental development organizations, and the private sector. The Bank's involvement in onchocerciasis control has helped mobilize funds, giving confidence to other donors. More than U. S.$800 million was raised for both the OCP and APOC (excluding the initial costs of Mectizan). With these funds and the commitment of the partners involved, high coverages have been achieved in the Mectizan distributions. The Bank is confident that, during the years to come, the partners will continue their success, and that the APOC will achieve its goals by the target date for its closure, in 2015.

The Leogane, Haiti demonstration project: decreased microfilaremia and program costs after three years of mass drug administration.

To support the global program to eliminate lymphatic filariasis (LF), well-monitored demonstration projects are important for defining the relationship between coverage and reductions in microfilaremia. We are using mass treatment with diethylcarbamazine (DEC) and albendazole in an effort to eliminate LF from Leogane, Haiti. Wuchereria bancrofti microfilaremia prevalence at baseline ranged from 0.8% to 15.9% in four sentinel sites. After three rounds of DEC-albendazole mass drug administration (MDA), both microfilaremia prevalence and intensity decreased dramatically. Mild and moderate adverse reactions after treatment were common, especially after the first MDA, but decreased after subsequent MDAs. Drug coverage for the first year was estimated to be 72%, but concerns about adverse reactions appeared to decrease drug coverage in the second MDA. As a result of community education efforts that focused on providing a greater understanding of adverse reactions, coverage increased dramatically for the third round. Program efficiency increased substantially; the costs per person treated for three rounds of MDA were 2.23 US dollars, 1.96 US dollars, and 1.30 US dollars per person, respectively. The Leogane experience highlights the importance of adapting community education and mobilization campaigns to achieve and maintain good coverage.

Mass drug administration to eliminate lymphatic filariasis in India.

Mass drug administration (MDA) to eliminate lymphatic filariasis is already in place in 32 out of 83 endemic countries. Expansion of the MDA programme to other countries and within large countries such as India is necessary to achieve the goal of lymphatic filariasis elimination. However, expansion and sustenance of the global campaign to eliminate lymphatic filariasis requires commitment and allocation of funds by governments and donor agencies. This could be achieved, at least to some extent, by highlighting the benefits of the programme in relation to costs. On the basis of various studies in south India, this article assesses the costs, effectiveness and economic and social benefits of the MDA programmes aimed at eliminating lymphatic filariasis.

Frequency, severity, and costs of adverse reactions following mass treatment for lymphatic filariasis using diethylcarbamazine and albendazole in Leogane, Haiti, 2000.

In October 2000, 71,187 persons were treated for lymphatic filariasis using albendazole and diethylcarbamazine (DEC) or DEC alone in Leogane, Haiti. We documented the frequency of adverse reactions, severity and cost of treatment. Adverse reactions were classified as minor, moderate, or severe. Overall, 24% (17,421) of the treated persons reported one or more adverse reactions. There were 15,916 (91%) minor and 1502 (9%) moderate adverse reaction reports. Men outnumbered women 2:1 in reporting moderate problems. Three patients, representing roughly one in 25,000 persons treated, were hospitalized with severe adverse reactions judged to be treatment-associated by physician review. The cost per person treated for adverse reactions was more than twice the cost per person treated for lymphatic filariasis (dollar 1.60 versus dollar 0.71). Severe adverse reactions to lymphatic filariasis treatment using DEC with or without albendazole are uncommon. Minor and moderate reactions are more commonly reported and their management represents a challenge to lymphatic filariasis elimination programs.

Comparison of methods for estimating drug coverage for filariasis elimination, Leogane Commune, Haiti.

In the global effort to eliminate lymphatic filariasis, annual mass treatments are conducted with diethylcarbamazine (DEC) or ivermectin, combined with albendazole. The success of this strategy depends on achieving high levels of drug coverage, which reduces the number of persons with circulating microfilariae so that transmission of the parasite is interrupted. Because resources are often limited, a simple, inexpensive, and reliable method to estimate drug coverage is needed. During the period December 2000 to February 2001, three methods were used to assess drug coverage in Leogane Commune, Haiti: a probability survey using a cluster sample design (n = 1421 persons); a distribution-point survey based on a convenience sample of houses near the distribution points (n = 4341 persons); and a survey based on a convenience sample of primary schools (n = 5036 children). The coverage estimations were 71.3% (95% CI 66.7-75.9), 73.6% (95% CI 70.1-77.0), and 77.8% (95% CI 73.5-82.1), respectively. Survey costs for the probability, distribution point, and school surveys were US$2217, US$979, and US$312, respectively. The 2 convenience sampling methods provided point estimates of drug coverage that were similar to those of the probability survey. These methods may have a role for monitoring drug treatment coverage between less frequent, but more costly, probability sample surveys.

Cost-effectiveness of the use of vector control and mass drug administration, separately or in combination, against lymphatic filariasis.

The costs and effects of two intervention strategies for the control of bancroftian filariasis-annual mass drug administrations (MDA) with a combination of diethylcarbamazine and ivermectin, with or without integrated vector control (VC)-were estimated in rural villages in South India. The aim was to compare the cost-effectiveness of MDA alone with that of MDA plus VC. Control of the local vector, Culex quinquefasciatus, was based on the application of polystyrene beads to cesspits, the treatment of drains with larvicidal Bacillus sphaericus and the stocking of wells with larvivorous fish. An itemized cost menu was used to cost MDA and MDA + VC, retrospectively. The annual transmission potential was used to assess the direct outcome of the disease-control methods, whereas the prevalence and intensity of microfilaraemia were used as indicators of the impact of each method. The per-capita costs were 1.49 U.S. dollars for two rounds of MDA, 1.70 U.S. dollars for 2 years of VC and, therefore, 3.19 U.S. dollars for 2 years of MDA + VC. Integration of VC with MDA did not appear to be cost-effective: it cost an estimated 1.80 U.S. dollars to stop an infective mosquito biting a villager using MDA alone but 3.32 U.S. dollars to achieve the same result using MDA + VC. Similarly, the cost to reduce the prevalence of microfilaraemia in a three-village group by 1% was only 96.62 U.S. dollars for MDA alone but 201.16 U.S. dollars when vector control was integrated. The implications of these results for the control and elimination of filariasis in Indian village communities, and the options for sharing and minimizing costs, are discussed.

Onchocerciasis control in Nigeria: will households be able to afford community-directed treatment with ivermectin?

OBJECTIVES: To determine the level of affordability of community-directed treatment with ivermectin (CDTI) to households living in two onchocerciasis endemic Nigerian communities namely Toro in the north and Nike in the south. METHODS: The proportion of the cost of treating people with ivermectin will deplete in average monthly/projected annual household expenditure on food and health care, and on average monthly and projected annual household income were respectively calculated and used to determine the level of affordability of CDTI. Questionnaires administered to heads of households or their representatives were used to collect information on the household expenditures and income. The suggested unit CDTI cost of $0.20 was used. However, as a test of sensitivity, we also used the unit cost of $0.056 which some community based distributors are charging per treatment. RESULT: Using $0.20 as the unit treatment cost, this will consume less than 0.05% of average annual household income in both communities. It will equally deplete 0.05% of combined annual household expenditures on food and health care in both communities. However, using $0.056 as the unit treatment cost, then 0.02% of average annual household expenditure on health care, 0.01% average annual expenditure on combined health care and food, and 0.01% of average annual household income will be depleted. CONCLUSION: The households living in both communities may be able to afford CDTI schemes. However, the final decision on levels of affordability lies with the households. They will decide whether they can afford to trade-off some household income for ivermectin distribution.

Cost of mass annual single dose diethylcarbamazine distribution for the large scale control of lymphatic filariasis.

Economic analysis of the revised strategy to control lymphatic filariasis with mass annual single dose diethylcarbamazine (DEC) at 6 mg/kg body weight launched in one of the districts of Tamil Nadu in 1996 was carried out. This exploratory study, proposed for five years in 13 districts under 7 states on a pilot scale through the Department of Public Health is an additional input of the existing National Filaria Control Programme in India. A retrospective costing exercise was undertaken systematically from the provider's perspective following the completion of the first round of drug distribution. The major activities and cost components were identified and itemized cost menu was prepared to estimate the direct (financial) and indirect (opportunity) cost related to the implementation of the Programme. The total financial cost of this Programme to cover 22.7 lakh population in the district was Rs. 22.05 lakhs. The opportunity cost of labour and capital investment was calculated to be Rs. 7.98 lakhs. The total per capita cost was Rs. 1.32, with Rs. 0.97 and Rs. 0.35 as financial and opportunity cost respectively. Based on these estimates, the implementation cost of the Programme at Primary Health Centre (PHC) level was calculated and projected for five years. The additional financial cost for the existing health care system is estimated to be Rs. 27,800 per PHC every year. DEC tablets (50 mg) was the major cost component and sensitivity analysis showed that the cost of the Programme could be minimized by 20 per cent by switching over to 100 mg tablets. The analysis indicates that this Programme is a low-cost option and the results are discussed in view of its operational feasibility and epidemiological impact.