• A Survey on Vaccine Efficacy in the City of Bongor (Chad) and its Operational Consequences for the Vaccination Program

      Luthi, J; Kessler, W; Boelaert, M; Médecins sans Frontières, Bruxelles, Belgique. (Published by WHO, 1997)
      A measles epidemic occurred in the city of Bongor, Chad, from 22 September 1993 to 26 June 1994. A total of 792 patients were hospitalized, with a case fatality rate of 5.2%. After the epidemic, the district management team evaluated the expanded programme on immunization (EPI). Through a cluster survey the attack rate was estimated to be 29.1% (95% confidence interval (CI) = 20.4-37.8%) for the age group 12-59 months (n = 206). For this same age group, the measles immunization coverage was estimated to be 44.2% (95% CI = 34.6-53.8%) and the vaccine efficacy 9.5% (95% CI = 0-41.5%). Several flaws in the logistic handling of the vaccines and especially in the cold chain were identified. These results indicated a serious management problem in the EPI, which the district team then immediately started to rectify. The method used to estimate the immunization coverage and efficacy in the study is rapid and low cost. Also, it is feasible at the district level and permits identification of management problems in the EPI.
    • A Comparison of Cluster and Systematic Sampling Methods for Measuring Crude Mortality.

      Rose, A; Grais, R; Coulombier, D; Ritter, H; Epicentre, Paris, France. angela.rose@epicentre.msf.org (Published by WHO, 2006-04)
      OBJECTIVE: To compare the results of two different survey sampling techniques (cluster and systematic) used to measure retrospective mortality on the same population at about the same time. METHODS: Immediately following a cluster survey to assess mortality retrospectively in a town in North Darfur, Sudan in 2005, we conducted a systematic survey on the same population and again measured mortality retrospectively. This was only possible because the geographical layout of the town, and the availability of a good previous estimate of the population size and distribution, were conducive to the systematic survey design. RESULTS: Both the cluster and the systematic survey methods gave similar results below the emergency threshold for crude mortality (0.80 versus 0.77 per 10,000/day, respectively). The results for mortality in children under 5 years old (U5MR) were different (1.16 versus 0.71 per 10,000/day), although this difference was not statistically significant. The 95% confidence intervals were wider in each case for the cluster survey, especially for the U5MR (0.15-2.18 for the cluster versus 0.09-1.33 for the systematic survey). CONCLUSION: Both methods gave similar age and sex distributions. The systematic survey, however, allowed for an estimate of the town's population size, and a smaller sample could have been used. This study was conducted in a purely operational, rather than a research context. A research study into alternative methods for measuring retrospective mortality in areas with mortality significantly above the emergency threshold is needed, and is planned for 2006.
    • Comparison of Generic and Proprietary Sodium Stibogluconate for the Treatment of Visceral Leishmaniasis in Kenya.

      Moore, E; O'Flaherty, D; Heuvelmans, H; Seaman, J; Veeken, H; de Wit, S; Davidson, R N; Médecins Sans Frontières-Holland (MSF-H) Kala-azar Programme, South Sudan/Kenya. (Published by WHO, 2001)
      OBJECTIVE: To compare the use of generic and proprietary sodium stibogluconate for the treatment of visceral leishmaniasis (kala-azar). METHODS: A total of 102 patients with confirmed kala-azar were treated in a mission hospital in West Pokot region, Kenya, with sodium stibogluconate (20 mg/kg/day for 30 days)--either as Pentostam (PSM) or generic sodium stibogluconate (SSG); 51 patients were allocated alternately to each treatment group. FINDINGS: There were no significant differences in baseline demographic characteristics or disease severity, or in events during treatment. There were 3 deaths in the PSM group and 1 in the SSG group; 2 patients defaulted in each group. Only 1 out of 80 test-of-cure splenic aspirates was positive for Leishmania spp.; this patient was in the SSG group. Follow-up after > or = 6 months showed that 6 out of 58 patients had relapsed, 5 in the SSG group and 1 in the PSM group. No outcome variable was significantly different between the two groups. CONCLUSION: The availability of cheaper generic sodium stibogluconate, subject to rigid quality controls, now makes it possible for the health authorities in kala-azar endemic areas to provide treatment to many more patients in Africa.
    • Mass Vaccination with a Two-Dose Oral Cholera Vaccine in a Refugee Camp.

      Legros, D; Paquet, C; Perea, W; Marty, I; Mugisha, N K; Royer, H; Neira, M; Ivanoff, B; Epicentre, Kampala, Uganda. (Published by WHO, 1999)
      In refugee settings, the use of cholera vaccines is controversial since a mass vaccination campaign might disrupt other priority interventions. We therefore conducted a study to assess the feasibility of such a campaign using a two-dose oral cholera vaccine in a refugee camp. The campaign, using killed whole-cell/recombinant B-subunit cholera vaccine, was carried out in October 1997 among 44,000 south Sudanese refugees in Uganda. Outcome variables included the number of doses administered, the drop-out rate between the two rounds, the proportion of vaccine wasted, the speed of administration, the cost of the campaign, and the vaccine coverage. Overall, 63,220 doses of vaccine were administered. At best, 200 vaccine doses were administered per vaccination site and per hour. The direct cost of the campaign amounted to US$ 14,655, not including the vaccine itself. Vaccine coverage, based on vaccination cards, was 83.0% and 75.9% for the first and second rounds, respectively. Mass vaccination of a large refugee population with an oral cholera vaccine therefore proved to be feasible. A pre-emptive vaccination strategy could be considered in stable refugee settings and in urban slums in high-risk areas. However, the potential cost of the vaccine and the absence of quickly accessible stockpiles are major drawbacks for its large-scale use.
    • Melarsoprol Versus Eflornithine for Treating Late-stage Gambian Trypanosomiasis in the Republic of the Congo.

      Balasegaram, M; Harris, S; Checchi, F; Ghorashian, S; Hamel, C; Karunakara, U; Medecins Sans Frontieres, London, England. manica.balasigaram@london.msf.org (Published by WHO, 2006-10)
      OBJECTIVE: To compare the effectiveness of melarsoprol and eflornithine in treating late-stage Gambian trypanosomiasis in the Republic of the Congo. METHODS: We analysed the outcomes of death during treatment and relapse within 1 year of discharge for 288 patients treated with eflornithine, 311 patients treated with the standard melarsoprol regimen and 62 patients treated with a short-course (10-day) melarsoprol regimen between April 2001 and April 2005. FINDINGS: A total of 1.7% (5/288) of patients treated with eflornithine died compared with 4.8% (15/311) of those treated with standard melarsoprol and 6.5% (4/62) of those treated with short-course melarsoprol. Patients treated with eflornithine tended to be younger and were more likely to have trypanosomes or higher white blood cell counts in their cerebrospinal fluid. The cumulated incidence of relapse among patients who attended at least one follow-up visit 1 year after discharge was 8.1% (11/136) for those treated with eflornithine, 14% (36/258) for those treated with standard melarsoprol and 15.5% (9/58) for those treated with shortcourse melarsoprol. In a multivariate analysis, when compared with eflornithine, standard melarsoprol was found to be a risk factor for both death (odds ratio (OR) = 2.87; 95% confidence interval (CI) = 1.03-8.00) and relapse (hazard ratio (HR) = 2.47; 95% CI = 1.22-5.03); when compared with eflornithine, short-course melarsoprol was also found to be a risk factor for death (OR = 3.90; 95% CI = 1.02-14.98) and relapse (HR = 6.65; 95% CI = 2.61-16.94). CONCLUSION: The effectiveness of melarsoprol treatment appears to have diminished. Eflornithine seems to be a better first-line therapy for treating late-stage Gambian trypanosomiasis in the Republic of the Congo.
    • Operational and Economic Evaluation of an NGO-led Sexually Transmitted Infections Intervention: North-Western Cambodia

      Carrara, V; Terris-Prestholt, F; Kumaranayake, L; Mayaud, P; Banteay Meanchey Projects, Cambodia/Médecins Sans Frontières, Amsterdam, The Netherlands. (Published by WHO, 2005-06)
      OBJECTIVE: Sexually transmitted infection (STI) services were offered by the nongovernmental organization Médecins Sans Frontières-Holland in Banteay Meanchey province, Cambodia, between 1997 and 1999. These services targeted female sex workers but were available to the general population. We conducted an evaluation of the operational performance and costs of this real-life project. METHODS: Effectiveness outcomes (syndromic cure rates of STIs) were obtained by retrospectively analysing patients' records. Annual financial and economic costs were estimated from the provider's perspective. Unit costs for the cost-effectiveness analysis included the cost per visit, per partner treated, and per syndrome treated and cured. FINDINGS: Over 30 months, 11,330 patients attended the clinics; of these, 7776 (69%) were STI index patients and only 1012 (13%) were female sex workers. A total of 15 269 disease episodes and 30 488 visits were recorded. Syndromic cure rates ranged from 39% among female sex workers with genital ulcers to 74% among men with genital discharge; there were variations over time. Combined rates of syndromes classified as cured or improved were around 84-95% for all syndromes. The total economic costs of the project were US 766,046 dollars. The average cost per visit over 30 months was US 25.12 dollars and the cost per partner treated for an STI was US 50.79 dollars. The average cost per STI syndrome treated was US 48.43 dollars, of which US 4.92 dollars was for drug treatment. The costs per syndrome cured or improved ranged from US 46.95-153.00 dollars for men with genital ulcers to US 57.85-251.98 dollars for female sex workers with genital discharge. CONCLUSION: This programme was only partly successful in reaching its intended target population of sex workers and their male partners. Decreasing cure rates among sex workers led to relatively poor cost-effectiveness outcomes overall despite decreasing unit costs.
    • Priority During a Meningitis Epidemic: Vaccination or Treatment?

      Veeken, H; Ritmeijer, K; Hausman, B; Medical Department, Médecins sans Frontières-Holland, Amsterdam, Netherlands. hans_veeken@amsterdam.msf.org (Published by WHO, 1998)
      From November 1995 to May 1996, a meningitis epidemic occurred in northern Nigeria. More than 75,000 cases and 8440 deaths (case fatality rate (CFR), 11%) were recorded. Médecins sans Frontières, in cooperation with the Nigerian government, carried out an assistance programme (support to case management, surveillance and mass vaccination) in three states (Bauchi, Kano, Katsina) where 75% of cases occurred. Cost analysis of this assistance in Katsina State reveals that case management and mass vaccination were efficient: US$ 35 per case treated and US$ 0.64 per vaccination. There was, however, a remarkable difference in cost-effectiveness between the two strategies. The cost per death averted by improved case treatment was estimated to be US$ 396, while the cost per death averted by vaccination was estimated to be US$ 6000. In large part this difference is attributed to the late start of vaccination: more than 6 weeks after the epidemic threshold had been passed. During meningitis epidemics in countries where surveillance systems are inadequate, such as in most of sub-Saharan Africa, curative programmes should have priority.
    • Report of the Commission on Intellectual Property Rights, Innovation and Public Health: A Call to Governments.

      't Hoen, E; Access to Essential Medicines Campaign, Médecins sans Frontières, Paris, France. ellen.t.hoen@paris.msf.org (Published by WHO, 2006-05)
    • Treatment Outcomes and Risk Factors for Relapse in Patients with Early-stage Human African Trypanosomiasis (HAT) in the Republic of the Congo.

      Balasegaram, M; Harris, S; Checchi, F; Hamel, C; Karunakara, U; Medecins Sans Frontieres, London, England. manica.balasigaram@london.msf.org (Published by WHO, 2006-10)
      OBJECTIVE: In 2002-03, the Republic of the Congo increased the threshold separating stage 1 and 2 cases of human African trypanosomiasis (HAT) from a cerebrospinal fluid (CSF) white cell count of 5 cells/mm(3) to 10 cells/mm(3). We aimed to assess whether the increased threshold of 10 cells/mm(3) is a safe indicator of stage 2 disease. METHODS: We assessed patients treated for stage 1 HAT caused by Trypanosoma brucei gambiense in the Republic of the Congo between April 2001 and April 2005. Patients with 0-10 cells/mm(3) in CSF were classed as stage 1 and treated with pentamidine. Patients with CSF of > 10 cells/mm(3) were classed as stage 2 and treated with either melarsoprol or eflornithine. We did a retrospective analysis of all patients treated after the September 2002 increase in threshold for classification of HAT disease stage 2, and who were eligible for at least 1 year of follow-up. Primary outcome was survival without death or relapse within 1 year of discharge. Risk factors for treatment failure, in particular CSF white cell count on diagnosis, were assessed. FINDINGS: Between September 2002 to April 2004, 692 patients eligible for our analysis were treated with pentamidine. All were discharged alive. Relapse rate was 5% (n = 33). The only identified risk factor for relapse was a CSF white cell count of 6-10 cells/mm(3) rather than 0-5 cells/mm(3) (adjusted hazard ratio 3.27 (95% confidence interval, 1.52-7.01); P = 0.002). CONCLUSION: A threshold of 5 white cells/mm(3) in CSF is safer than 10 cells/mm(3) to determine stage 2 HAT and reduce risk of relapse.