Our survey revealed that, among the African countries that conducted AFP surveillance and reported to WHO in 1999, the majority had designated surveillance officers, vehicles, and annual budgets. Moreover, most of the national polio eradication programs combined the surveillance for and response to AFP with other infectious diseases. Our investigation also revealed that certain countries that had prudently added other diseases to their AFP surveillance programs were also able to perform AFP surveillance adequately. However, the survey also indicated that additional staff, funds, and political commitment might be required if infectious disease surveillance and response is to improve in Africa.
AFP surveillance programs have instituted laboratory systems in countries and have formed networks between and within countries and with WHO-AFRO by providing portable computers with modems, telephone/facsimile lines, and electronic mail connections. Our survey results indicated that detection and confirmation of outbreaks of other infectious diseases has been conducted by using the resources and infrastructure of the AFP surveillance laboratory network, including the specimen transportation system. This can be further strengthened into a network of laboratories that can support the IDSR strategy. Joint information sessions for clinicians regarding polio-AFP surveillance and other diseases of public health importance within countries are already occurring and can be strengthened into a collaborative training effort for IDSR. Stronger links among epidemiologists and laboratorians are necessary to improve outbreak detection and control.
Our study determined that the majority of diseases that are integrated into AFP programs are vaccine-preventable diseases (e.g., measles and neonatal tetanus), indicating an ongoing linkage with other vaccination programs and disease-prevention activities. Other diseases included in AFP surveillance programs were epidemic-prone diseases (e.g., cholera and meningitis), reflecting the importance of epidemic response in general. Among the countries that achieved the surveillance target for AFP in 1999, the majority included 1–5 other infectious diseases in the AFP surveillance program, indicating that the judicious addition of a few diseases to a program such as AFP surveillance is feasible without adversely affecting the primary program.
Substantial fixed costs are involved in building and maintaining national surveillance and response systems and a limited number of countries can afford the cost of duplicative systems . Other targeted and substantially funded disease control programs (e.g., HIV/AIDS, malaria, tuberculosis) need to consider following the example of AFP surveillance and make investments in the surveillance and response infrastructure at the country level. Many of these categorical programs desire improved timeliness and completeness of district reporting and evidence-based decision making, which can be addressed by implementing IDSR activities.
To support surveillance activities as a necessary component of disease prevention and control activities, an urgent need exists to develop a consensus core set of surveillance and response indicators that are field-tested and that can be monitored routinely in a similar manner to the polio indicators, in addition to the existing surveillance evaluation frameworks [15, 16]. These indicators can then guide the strengthening of surveillance systems and the integration of other diseases into targeted disease-specific programs.
Contributions that were identified and attributable to the presence of AFP surveillance programs indicate that polio-eradication programs have gone beyond a purely vertical approach (i.e., disease-specific) toward one that is more horizontal (i.e., systems development). Improvements of infrastructure, capacity building, and provision of personnel can be used to develop the overall surveillance system for infectious diseases as long as the categorical program policies clearly support this approach. A lack of resources (e.g., staff, funds, vehicles, or fuel) were the main constraints to infectious disease surveillance that were identified in the survey – interestingly, training was not identified as a top constraint, possibly indicating that trained personnel already exist, at least within the AFP surveillance program. Managers of categorical programs are often uneasy regarding entrusting others with gathering surveillance data that are crucial to targeting and evaluating their programs. Therefore, ongoing training monitoring and periodic external evaluations should provide the quality assurance and credibility that integrated surveillance and response programs will need to reassure managers that they are basing decisions on reliable information.
This survey had a few limitations and we were unable to obtain responses from all the targeted countries. In certain countries, we could not contact possible respondents because of difficulties in communication, which could have led to introduction of bias in the survey because the non-respondents might have had substantially different answers to our questions than the respondents. Another possible limitation was that respondents were reporting on themselves and could have lacked objectivity additionally, the future employment and/or career development of the respondents may likely depend on their capacity to support other control programs and this may have introduced a bias in answering the questionnaire, although there is no way to determine this for certain. Further, the tool that we used did not have questions on the acceptability of AFP surveillance and the feasibility of IDSR and we also did not evaluate the cost of IDSR or the cost to maintain and sustain the infrastructure of the polio eradication initiative after polio is eradicated. We determined the performance of the AFP surveillance programs solely by non polio AFP rates because of the lack of widely used surveillance and response indicators at the time of the survey, however WHO-AFRO and CDC have recently begun work on a list of core indicators that will help monitor and evaluate the implementation of the IDSR process.
The findings of this survey have important implications for WHO-AFRO's initiative to improve surveillance, epidemic preparedness, and response in the African region. First, polio-eradication initiative staff, financial resources, and infrastructure can be used as one strategy to build IDSR in Africa. Because additional funds are needed for surveillance now and will be needed after polio is eradicated, other disease-specific programs, especially those focusing on epidemic prone diseases like malaria, might consider investing in general infectious disease surveillance following the polio example. Second, as surveillance and response capacity are developed in Africa, adding new diseases to existing or new surveillance systems should be on the basis of indicators of the surveillance system's capacity not to overload the surveillance system. Finally, the cadre of new people trained in surveillance by the polio-eradication initiative should be used for IDSR, and career paths should be provided for them as one lasting legacy of the poliomyelitis-eradication campaign in Africa.