The major burden of communicable diseases in Uganda remains attributable to preventable diseases ranging from endemic diseases such as malaria to emerging and re-emerging infections such as HIV/AIDS, viral haemorrhagic fevers, tuberculosis and cholera (MOH Uganda 1999; MOH Uganda 2000; Somda et al. 2009). Among the several strategies put in place by the Ugandan government to address this disease burden is a functional public health surveillance system with an early warning system (MOH Uganda 2001).

This system aims at timely and appropriate responses to priority disease threats that involve all stakeholders, including the government sectors (from national to community levels), the private sector and development partners (Perry et al. 2007).

Uganda adopted a decentralized health care system in 1993. Through decentralization, the country was divided into 45 districts. In 2001, the country was further divided into 56 districts, and in 2006, the number of districts increased to 80. The districts are further sub-divided into functional zones called health sub-district (HSDs) and within each HSD are hierarchal levels of health facilities, which offer a range of services (health centres I, II, III, IV and hospitals). For example, the level designated as Health Centre I is the most peripheral level of health services, with no permanent facility but with community or village health workers offering mainly preventive services within their communities. The referral level starts at the Health Centre IV, and then hospitals (both district and referral hospitals), which offer curative and surgical services in addition to preventive services (Anokbonggo et al. 2004).

In 1998, Member States of the Africa Region of the World Health Organization (WHO AFRO) adopted the Integrated Disease Surveillance (IDS) strategy with the intent to create integrated, action-oriented, district-focused public health surveillance systems (WHO AFRO 1999; WHO AFRO 2000). In 2001, due to the importance of linking surveillance to public health action, the strategy was renamed Integrated Disease Surveillance and Response (IDSR) (WHO AFRO and CDC 2001). The WHO framework for monitoring and evaluating surveillance and response systems for communicable diseases was designed around structures, quality and process (core and support functions), from which surveillance indicators were derived and adapted by several countries including Uganda (WHO 2004).

In preparation for the implementation of this strategy in Uganda, a baseline assessment of the available vertical surveillance systems was conducted in February 2000 (CDC 2000; WHO AFRO 2000). Findings from this assessment formed the basis for implementation of IDSR through integration of existing surveillance systems, which involved: (i) establishment of a co-ordination mechanism to link various surveillance systems to create an integrated system; (ii) harmonization of data collection tools; (iii) procurement of standardized data storage; and (iv) storing data in a uniform database where it is easily accessible to users and policy-makers. In Uganda, this co-ordinated approach to data collection, analysis, interpretation, use and dissemination was designed to guide decision-making for public health action.

Following the February 2000 assessment, a 5-year strategic plan of action was developed from which annual work plans with clear objectives were developed and launched in May 2000 (MOH Uganda 2000; Perry et al. 2007). The plan aimed at reducing the negative impact of epidemic threats through an early warning system and timely response. It sought to ensure the availability of disease data to monitor the progress of interventions for control, elimination or eradication of target diseases. Achievements in these areas would contribute to the overall health sector goal of reducing morbidity and mortality due to preventable causes.

It is worth noting that along the road to IDSR implementation, the need to integrate laboratory surveillance was emphasized, in terms of personnel, reagents and supplies, as well as the confirmation process for reported disease epidemic threats. The evaluation of laboratory involvement in the subsequent years of IDSR implementation identified continued weaknesses in terms of trained laboratory personnel, especially at district and sub-district levels, processing of laboratory results and ability to link laboratory results with the weekly surveillance reporting system, which on its part reflected a steady increase in timeliness of reporting priority diseases (Nsubuga et al. 2009).

This review provides information on the progress of IDSR after several years of implementation. It highlights the costs involved, successes and the challenges faced during the implementation of the IDSR strategy in Uganda. The information from this review is important for strengthening IDSR, which not only contributes to the control of communicable disease in Uganda, but also enhances the capacity to implement the World Health Organization’s International Health Regulations (2005), a legally-binding agreement that provides a new framework for co-ordinating and managing public health threats, which came into effect in June 2007.

Uganda has been following a systematic approach to planning and implementation of the IDSR strategy since 2000. Periodic reviews of the indicators monitoring core and support functions were recommended by WHO AFRO, the US Centers for Disease Control (CDC), ministries of health and all implementing partners as a means for assessing national surveillance systems (WHO AFRO 1999; WHO AFRO 2000; WHO 2002). We evaluated the progress of IDSR implementation in Uganda at national, district and health facility levels from 2001 to 2007.

At national level we reviewed the progress of IDSR implementation through analysis of the national core indicators adapted from the standard WHO AFRO IDSR indicators listed in Table 1. The implementation of IDSR at national level was evaluated through analysis of the core IDSR indicators, funding for implementation and comparison of costs before and after IDSR implementation. Analysis of IDSR core indicators focused on completeness and timeliness of weekly epidemiological data, morbidity and mortality data for cholera and meningococcal meningitis as tracer conditions for IDSR performance from 2001 to 2007 (Table 2). Completeness was computed based on proportion of districts and health units per district which submit weekly and monthly reports in a calendar year. Timeliness was computed based on proportion of districts that submit timely reports in a calendar year. Timely submission of reports was receipt of district epidemiological data by Thursday following the end of the previous epidemiological week. Attack rates (AR) and case fatality rates (CFR) were computed based on the district level weekly and monthly reports of cases, deaths and at-risk populations per evaluation year. Cholera and meningococcal meningitis were selected among the epidemic prone diseases under surveillance as the tracer epidemic diseases to monitor attack and case fatality rates regularly. Table 1

IDSR core indicators and their targets

The adapted IDSR core indicators (Table 1) and their targets were included in the national surveillance databases in order to routinely monitor progress with essential surveillance functions, such as detection and reporting of priority diseases, analysis and interpretation of data, investigation (including laboratory confirmation of suspected outbreaks) and response to epidemic threats, and provision of feedback.

Denominators were determined by the number of units for a given indicator that exist in the country. For example, total number of health units in a district constitute the denominator for timeliness or completeness of reporting in a given period, and the total outbreaks reported in a country constitute the denominator for outbreak timely investigation and response. The designation of denominators, therefore, constituted the unit base, which was in the form of structures such as health units, health workers or health events.

We also examined the national level funding for IDSR implementation from 2000/2001 to 2007/2008. We conducted a cost analysis to compare funding for surveillance before (1996–99) and during IDSR implementation (see Table 5) using annual budgets and financial reports. Data on funding from 1996 to 1999 are aggregated because the national level vertical programmes conducted the surveillance functions directly at district and regional levels. Decentralization of the financial management levels had not yet taken effect. However, from the year 2000, the funds for IDSR implementation were disbursed directly to national, regional and district levels. The mean costs analysed were in line with key resources involved in implementation of IDSR (as shown in Table 5).

At district and health facility level, an evaluation on the performance of IDSR core and support functions was carried out in 2004. In order to allow comparison and determine progress, the 2004 IDSR evaluation was based on the same parameters as the IDSR baseline assessment in 2000. In the 2000 IDSR assessment, eight of the then existing 45 districts of Uganda were sampled. A multi-stage stratified sampling was done in which four regions were selected purposely to have regional representation. In each region, two districts were selected by simple random sampling, giving a total of eight districts, and in each district, eight health facilities were selected again by simple random sampling. Because the 2000 baseline assessment was based on a small sample, comparison with the 2004 evaluation poses a limitation.

The evaluation focused on the IDSR structures at national, district and health facility levels, core and support functions, inputs, processes, outputs and outcomes of IDSR, based on the key interventions from the 2000 IDSR Plan of Action. We used similar methods to collect data, including structured questionnaires administered to personnel at health facility, district and national levels; observation checklists and key informant interviews. The sampled districts and health facilities were part of IDSR implementation from the time of its inception in 2000 to the time the evaluation was conducted in 2004.

We analysed the 2004 evaluation survey results to compare the performance of district and health-facility levels in 2004 with the 2000 baseline (CDC 2000). The 2004 evaluation of the district and health-facility levels was based on a three-stage sampling technique. In the first stage, two districts were selected by random sampling from each of the 10 geographical regions, giving a total of 20 districts for the evaluation out of 56 in the country. In the second stage at district level, two Health Sub-Districts (HSDs) were selected by simple random sampling, giving a total of 40 HSDs from the 20 districts. HSDs are sub-operational levels with a health facility capable of handling outpatient and inpatient health care services, and an oversight role to lower-level health facilities in their catchment area. To assess performance at the health facility level, in the 3rd stage, a total of 217 health units (both government and private, at different levels) were selected through multi-stage random sampling.

The evaluation used both quantitative and qualitative methods, with a standardized questionnaire for most aspects and key informant interviews at national and district levels. The tools were administered to a sample of health facility staff who were the in-charges of the facilities, and were therefore purposely sampled to collect information on the IDSR organizational structure, flow of information, list of diseases and conditions under surveillance, availability of guidelines and standards, feedback mechanism, as well as training in IDSR.

While some indicators have eroded and substantial challenges remain, this review demonstrates that significant successes were nonetheless achieved during the first eight years of IDSR implementation in Uganda. There is a functional IDSR system in place and advocacy has been established, resulting in a marked improvement in IDSR performance. For example, at the national level, there is commendable progress in the implementation of IDSR as demonstrated by several indicators such as the completeness and timeliness of data reporting from the districts. There has also been more timely detection and response to acute outbreaks of infectious diseases. While IDSR was initially funded more fully by the government, and subsequently declining government input was temporarily offset by contributions from other sources, the most substantial improvements in IDSR performance indicators occurred in the context of stronger financial support than currently exists. The good progress with IDSR indicators suggested that there is a link between high political and financial commitment and the steady progress of IDSR performance. Similarly, at district and health-facility level, the performance in the indicators such as case or event detection, laboratory surveillance, data analysis, training, and outbreak investigation and response was satisfactory.

However, it was also observed that some critical indicators, including the capacity to confirm priority diseases such as malaria and tuberculosis, were still very low, suggesting that the laboratory component of IDSR in Uganda needs further strengthening (Vogt 1996; Shears 2000a; Kariuki Njenga et al. 2008; Nsubuga et al. 2009).

The rapid increase in the number of health districts from 45 in 2001 to 80 in 2006 has created new challenges to the implementation of IDSR. Whereas decentralization aims at bringing services closer to the people, maintaining a functional surveillance system amidst such rapid changes can be very challenging and requires adequate advance planning (Anokbonggo et al. 2004). New surveillance officers had to be identified and trained for each new district and the surveillance infrastructure reviewed to handle this change. The new surveillance officers needed logistical and transport support so as to conduct supervision of IDSR implementation and in some situations such support was not available.

The review of financial resources revealed a steady decline in funding allocations for the national level. Such a decline in funding support is likely to affect the performance of the IDSR strategy in Uganda. There are already early indications that diminished funding is possibly contributing to the decline in gains made by IDSR, as evidenced by the decline in the timeliness and completeness of reporting in 2005–07, after initial gains through 2000 to 2004. To reverse this decline, renewed efforts are needed by the government, development partners and districts to develop new plans of action with definite financial and technical commitment (Shears 2000b).

Although the vertical surveillance systems existing before the inception of IDSR presented a challenge to integrated surveillance, the readiness for several funders to adapt the IDSR model seems to favour the latter. The established structures from community to district and national level appear to be set to overcome this challenge. It is important to note, however, that programmes intent on a vertical surveillance approach still exist, mainly due to selected external vertical funding. Our observation from the cost analysis results in Table 5 shows that minimal funding trickled down to lower levels from the vertical surveillance systems operating before IDSR was started. Comparison of the mean costs for IDSR implementation for the period before and after 2000 revealed that although there was an improvement in the per capita input, funding remained low, as seen in a similar analysis by Somda et al. (2009). Even with the low cost for implementing IDSR, the benefits as reflected in the earlier results appeared to be enormous.

Despite the challenges observed, there has been a demonstrable improvement in the IDSR performance over the period 2001 to 2007 at all levels. Such a functional IDSR system was the basis for the early and quick detection, investigation and response to epidemics such as Marburg and Ebola viral haemorrhagic fevers in 2007, and likely contributed to the decreasing CFR of the tracer epidemic diseases.

WHO/AFRO has agreed to use IDSR as the vehicle for core capacity strengthening for the implementation of the revised International Health Regulations (2005) (The Lancet 2007; Kicman-Gawlowska 2008; Kicman-Gawlowska 2009). However, without sustained human, financial and logistical support, as well as institutionalization in the core agencies and budgets of public health, the successes and gains made in recent years could be lost and the core capacities for the International Health Regulations (2005) may not be achieved. Uganda has been and should continue to be a model country for IDSR in Africa (Weekly Epidemiological Record 2003). Renewed political and financial commitment is needed to sustain these successes.

We therefore conclude that improvements in IDSR resulted in better preparedness and more timely detection and response, which translated into reduced CFR. These gains were achieved through a relatively high level of funding, technical support from CDC and WHO, and in-service training in IDSR core functions. Continued support is needed to maintain and expand the gains made through IDSR implementation.

The implementation of IDSR, the performance monitoring and evaluation were funded by the Government of Uganda, World Health Organization (WHO), US Centers for Disease Control and Prevention (CDC), USAID African Bureau and the Rockefeller Foundation. The review of the data and writing of this manuscript was supported financially by the Ministry of health, WHO and CDC. WHO and CDC funded a writing workshop where the authors started writing the manuscript. They also provided technical support for data analysis and interpretation, and contributed to the writing of the manuscript. Pre-submission review and clearance was also done by CDC-Atlanta.

None declared.