Stanley O. Foster

Evaluation of a mass measles immunization campaign in Yaoundé, Cameroun

A mass measles immunization campaign carried out in Yaoundé, Cameroun, has been evaluated. Sixty per cent of the children were immune to measles at the time of the campaign. Only 51% of the susceptible children received vaccine. This was caused by a lack of attendance at the vaccination centres and errors in the selection of children given vaccine. The vaccine administered was relatively ineffective: 40% seroconversion. Difficulties which probably contributed to the low seroconversion rate included sub-optimal vaccine titre, inadequate doses of vaccine, and the relatively long time of vaccine utilization under tropical temperatures. Overall, 83% of the vaccine given to the vaccinating team was wasted. Future immunization campaigns can be improved through better screening of the children, improved handling of the vaccine, the use of marker vaccines, and improved health education.

Evaluating Public Health Responses to Reintroduced Smallpox via Dynamic, Socially Structured, and Spatially Distributed Metapopulation Models

The risk of smallpox reintroduction has motivated preparations in potential target countries. After reproducing the spatiotemporal pattern after the 1972 importation into Yugoslavia via coupled, biologically realistic systems of ordinary differential equations, we developed dynamic population models with current US age distributions and typical spatially distributed social structures. Surveillance and containment (S&C) coupled with vaccination of 95% of hospital-based health care workers (HCWs) within 2 days after the first diagnosis (estimated to be 18 days after aerosol release) were modeled after simulated exposure of 10, 50, or 10,000 people in various settings. If 90% of patients were isolated within days after symptom onset and 75% of contacts were vaccinated and monitored, S&C would reduce cases by 82%-99%. Preemptive immunization of HCWs, closing of schools, and even vaccination of as many as 80% within 1 week would have small marginal benefits. Preparations should emphasize stockpiling vaccine, training HCWs, improving laboratory capacity, and fostering an understanding of S&C.

From smallpox eradication to contemporary global health initiatives: Enhancing human capacity towards a global public health goal

The eradication of smallpox owes its success first and foremost to the thousands of lay health workers and community members who, throughout the campaign and across continents, took on the roles of advocates, educators, vaccinators, care providers and contributors to epidemic surveillance and containment. Bangladesh provides a good example where smallpox eradication and the capacity enhancement needed to achieve this goal resulted in a two-way mutually beneficial process. Smallpox-dedicated staff provided community members with information guidance, support and tools. In turn, communities not only created the enabling environment for smallpox program staff to perform their work but acquired the capacity to perform essential eradication tasks. Contemporary global health programmes can learn much from these core lessons including: the pivotal importance of supporting community aspirations, capacity and resilience; the critical need to enhance commitment, capacity and accountability across the workforce; and the high value of attentive human resources management and support. We owe to subsequent global disease control, elimination and eradication ventures recognition of the need for social and behavioural science to inform public health strategies; the essential roles that civil society organizations and public-private partnerships can play in public health discourse and action; the overall necessity of investing in broad-based health system strengthening; and the utility of applying human rights principles, norms and standards to public health policy and practice.

Malaria control in the municipality of San Esteban, Honduras

OBJECTIVES To assess the burden of malaria in San Esteban, Department of Olancho, Honduras, and provide recommendations for control. METHODS Malaria causes appreciable morbidity in San Esteban. In 2006, health workers reported an increase in malaria cases and requested recommendations for control. In 2005, 385 cases (Plasmodium vivax, 316; P. falciparum, 69) were detected from 4 007 blood smears in the San Esteban laboratory (slide positivity rate = 9.6%). During May-July 2006, we assessed the burden of malaria and made recommendations. We reviewed epidemiologic data from slide-confirmed malaria cases in 2005 and 2006 and conducted a knowledge, attitudes, and practices survey in households to assess malaria diagnostic, treatment, and prevention practices. RESULTS During May-July 2006, 143 laboratory-confirmed malaria cases were detected (P. vivax, 134; P. falciparum, 9) in San Esteban, compared with 104 (P. vivax, 79; P. falciparum, 25) in May-July 2005. From January 2005 to July 2006, 538 cases were detected in San Esteban, with increased frequency in May-October and the highest incidence in children 0-14 years old. We administered 112 surveys in 19 communities. Seventy percent of respondents reported a history of malaria in a household member, with the highest frequency reported in mothers (45%) and children under 14 years old (37%). Most households did not have mosquito protection such as bed nets, screens, or indoor residual insecticide. CONCLUSIONS Malaria is ongoing in San Esteban, with increased incidence in children. We recommend increased availability and promotion of insecticide-treated bed nets, improved timing and coverage of indoor residual spraying, and improved community malaria practices through education sessions.

Smallpox eradication in Bangladesh, 1972-1976.

Rahima Banu, the worlds last endemic case of severe smallpox, Variola Major, developed rash on October 16, 1975 on Bhola Island, Bangladesh. Achieving eradication in a country destroyed by war challenged the achievement of smallpox eradication. Between January 1, 1972 and December 31, 1975, 225,000 smallpox cases and 45,000 smallpox deaths occurred. Adapting the global smallpox eradication strategies of surveillance, the detection of smallpox cases, and containment, the interruption of smallpox transmission, utilized progress toward three objectives to monitor performance: (1) surveillance - the percent of smallpox infected villages detected within 14 days of the first case of rash, (2) knowledge of the reward - public knowledge of the current amount of the reward for reporting smallpox, and (3) containment - the percent of infected villages interrupting smallpox transmission within 14 days of detection. Failures to achieve these objectives led to the identification and implementation of improved strategies that eventually achieved eradication. Essential to this success was a tripartite partnership of the citizens of Bangladesh, the Bangladesh Ministry of Health, its field staff, and staff and resources mobilized by the World Health Organization.