Successes That Strengthened Weak Health Systems
Countries have achieved other successful public health interventions in contexts of weak health systems and implemented them in ways that also strengthened these health systems. Controlling onchocerciasis in Sub-Saharan Africa and eliminating polio in Latin America and the Caribbean are two illustrations of this process.
Approximately 18 million people live in areas where onchocerciasis is endemic, 99 percent of them in Sub-Saharan Africa (DCP2, chapter 22). The disease is caused by a microscopic worm that infects humans through the bite of an infected blackfly that breeds in the fast-moving waterways of Sub-Saharan Africa. The victim's body is eventually infested with worms, resulting in a range of debilitating symptoms, including blindness. In endemic areas, more than a third of the adult population may be blind, and infection often approaches 90 percent of the population. Because of fear of the disease, people abandoned vast areas of fertile riverside land.
" from 1974 to 2002, the control efforts prevented 600,000 cases of blindness, permitted 18 million children to be born free from the risk of river blindness, and rendered about 25 million hectares safe for resettlement and cultivation."
Control efforts, which were launched in 1974, have included weekly aerial spraying of breeding sites to kill the blackfly that spreads the disease and distribution of a new drug, ivermectin, that kills the worms in human beings. The impact has been immense. Key features of the effort included collaboration by many organizations and agencies, public-private partnership with the producer of ivermectin, and long-term funding. Initial successes led to subsequent and larger commitments such that from 1974 to 2002, the control efforts halted transmission in 11 West African countries, prevented 600,000 cases of blindness, permitted 18 million children to be born free from the risk of river blindness, and rendered about 25 million hectares of arable land safe for resettlement and cultivation. The control efforts achieved this despite the extreme poverty of these countries, the dispersal of populations in remote villages, the countries' inadequate health systems, a shortage of health workers, and the imperative of maintaining activities (including uninterrupted weekly aerial spraying of larvicide) despite civil and regional conflicts and coups.
Follow-up programs have emphasized long-term sustainability, because killing all the worms requires annual drug treatment for 15 to 20 years, and to this end have pioneered a system of community-directed treatment. This is a framework through which thousands of communities organize and manage ivermectin treatment locally. In some areas, the coordinators of the ivermectin distribution program are the only health workers to reach every village. Indeed, some people have suggested that even though the community-directed treatment framework was originally designed for onchocerciasis control, it could become the backbone of health systems and be used to distribute vitamin A, azithromycin (to treat trachoma), albendazole (to treat lymphatic filariasis), and even vaccines and HIV/AIDS drugs. Thus "the impact of the successful ComDT [community directed treatment] system extends beyond the treatment and prevention of river blindness. The system offers a valuable entry point for other community-directed health interventions in neglected communities with little or no access to traditional health services and a vehicle for strengthening the overall health system in developing countries" (Levine and others 2004, p. 62).
"As recently as 1988, 125 countries were endemic for polio. By the end of 2003, just six countries reported polio"
The elimination of polio in Latin America and the Caribbean offers some parallels. As recently as 1988, 125 countries were endemic for polio (DCP2, chapters 20 and 62). By the end of 2003, because of a massive, well-targeted vaccination and surveillance campaign, just six countries reported polio cases and none of these were in Latin America and the Caribbean.
The elimination of polio faces particular challenges because of the nature of the disease. The causative virus is extremely contagious and, while usually transmitted by fecal-oral contact, can survive for as long as two months outside the body, residing in pools, drinking water, food, and clothing. Transmission can go undetected because 90 percent or more of carriers develop no symptoms. When symptoms do develop, they are not always recognizable as polio. Indeed, one distinctive and confirmed case of polio paralysis implies that the community has another 2,000 to 3,000 contagious carriers whose only sign of infection may be a fever (Levine and others 2004, p. 40). Eliminating such a disease is challenging even where health systems are strong.
With the inclusion of the oral polio vaccine in the Expanded Program on Immunization as of 1977, the success of initial efforts in Latin America was impressive. By 1981, the incidence of polio in the region had been halved and the number of countries reporting cases of polio had dropped from 19 to 11. By 1984, coverage with the vaccine reached 80 percent. This improvement encouraged the Pan American Health Organization to mount an all-out campaign to eliminate polio from the region.
Launched in 1985, the campaign had a striking feature—the coordination among international, regional, and national public and private organizations. This unprecedented coalition pursued a strategy to strengthen surveillance so that health workers could identify, rapidly respond to, and contain any outbreaks. It also bolstered polio immunization coverage, so that even countries with less robust health infrastructures and weaker routine immunization programs could achieve impressive results. This was done through such means as national vaccine days, which took place twice a year and during which children under five were inoculated regardless of whether or not they had been vaccinated previously.
"The polio campaign left an enduring legacy for health systems in Latin America and the Caribbean"
The polio campaign left an enduring legacy for health systems in Latin America and the Caribbean by tackling polio in such a way that the campaign became "a stepping stone to strengthening the entire Expanded Program on Immunization, to improving health infrastructure throughout the region, and to establishing a greatly needed surveillance system to monitor the impact of interventions on the reduction of polio and other diseases" (Levine and others 2004, p. 41). In addition to enhancing infrastructure and improving the capacity for disease control, the polio campaign also built capacity for national health planning in that countries are now adapting the process of developing annual action plans for the polio campaign for other initiatives, including improving and extending maternal and child health services.
