Integrated disease surveillance and response systems in resource-limited settings

Infectious diseases are a major public health burden causing millions of deaths every year. Government authorities need to be able to monitor disease incidence and evaluate their interventions for disease control. Monitoring the status of infectious diseases is one of the most challenging problems facing the public health sector, and epidemiological surveillance systems for infectious diseases, particularly notifiable diseases are essential. Despite initiatives to encourage reporting of infectious diseases, underreporting and poor surveillance are on-going challenges for many developing countries. Most surveillance systems in these settings use traditional paper-based methods, which are both inefficient and impractical. There is a need for alternative tools to strengthen infectious disease surveillance systems in resource-limited settings. The remarkable progress made in mobile computing technology has the potential to improve infectious disease surveillance systems. However, user experience in digital technologies and infrastructure needs to be given greater attention. My study investigated the use of mobile phone devices as surveillance tools in health information systems. A mobile phone-based surveillance system was developed and applied in Tanzania as an alternative approach to traditional paper-based systems. Using this system different factors that affect the usability of mobile phone-based systems were investigated, by examining the quality of surveillance data in the context of completeness, timeliness and costs. After two years of operation in twenty-eight districts in southern Tanzania, numerous factors were identified that affect user accuracy and speed of use of the mobile phone-based surveillance. These include user experience in digital technology, particularly mobile device ownership; digital technology literacy, such as access and use of SMS and user’s age. The mobile phone-based surveillance system was more accurate compared to the traditional paper-based system with greater data reporting, more complete data and timelier reporting. Initially the mobile phone-based surveillance system required more capital investment, although the running costs of paper-based surveillance were greater. The utility of the mobile phone-based surveillance in monitoring and evaluating large-scale rabies control interventions was examined and the data produced was used to analyse the impacts of interventions on reducing disease incidence. Significant relationships were detected between the incidence of reported bite injuries in the focal district the previous month and in neighbouring districts that month, with more injuries detected in mainland Tanzania than on the island of Pemba. The relationship between bite injuries and vaccination coverage was complicated, with some evidence that vaccination reduced bite incidence. However, more data and a better model are needed to fully understand the impact of vaccination on bite incidence. The system provided timely information on the implementation of control measures and incidence of bite injuries, vital for improving control efforts. Use of automated short text messages (SMS) as part of the mobile phone-based surveillance was assessed to determine whether they could improve patient’s adherence to treatment regimens. Patients who received SMS reminders had significantly better compliance than those who did not, with attendance improved by at least 10%. Use of SMS reminders has the potential to improve patients’ compliance in other treatment regimens that require repeat clinic visits or administration of medicines. This thesis documented how the use of mobile phone devices can be used to improve surveillance in resource-limited settings. The use of effective integrated surveillance system could empower major stakeholders concerned with public health problems by providing them with appropriate real-time information on disease incidence and control interventions. In the final chapter the challenges encountered and insights gained in the application of mobile computing in strengthening infectious diseases surveillance are discussed. Despite infrastructural challenges such as unreliable power and Internet, mobile computing technologies can improve patient care and authorities can be prompted in a timely manner about infectious disease outbreaks and of supply shortages. In conclusion, innovative tools that can strengthen and integrate human and animal surveillance can improve the control and prevention of infectious diseases. Mobile phones have great potential for this, and can be used to strengthen health information systems

Estimating the size of dog populations in Tanzania to inform rabies control

Estimates of dog population sizes are a prerequisite for delivering effective canine rabies control. However, dog population sizes are generally unknown in most rabies-endemic areas. Several approaches have been used to estimate dog populations but without rigorous evaluation. We compare post-vaccination transects, household surveys, and school-based surveys to determine which most precisely estimates dog population sizes. These methods were implemented across 28 districts in southeast Tanzania, in conjunction with mass dog vaccinations, covering a range of settings, livelihoods, and religious backgrounds. Transects were the most precise method, revealing highly variable patterns of dog ownership, with human/dog ratios ranging from 12.4:1 to 181.3:1 across districts. Both household and school-based surveys generated imprecise and, sometimes, inaccurate estimates, due to small sample sizes in relation to the heterogeneity in patterns of dog ownership. Transect data were subsequently used to develop a predictive model for estimating dog populations in districts lacking transect data. We predicted a dog population of 2,316,000 (95% CI 1,573,000–3,122,000) in Tanzania and an average human/dog ratio of 20.7:1. Our modelling approach has the potential to be applied to predicting dog population sizes in other areas where mass dog vaccinations are planned, given census and livelihood data. Furthermore, we recommend post-vaccination transects as a rapid and effective method to refine dog population estimates across large geographic areas and to guide dog vaccination programmes in settings with mostly free roaming dog populations

Differences in Life-Saving Obstetric Hemorrhage Treatments for Women with Abortion Versus Nonabortion Etiologies in Tanzania.

Complications from unsafe abortion are among the major causes of preventable maternal morbidity and mortality, which may be compounded by delays and disparities in treatment. We conducted a secondary analysis of women with symptoms of hypovolemic shock secondary to severe obstetric hemorrhage in Tanzania. We compared receipt of three lifesaving interventions among women with abortions versus other maternal hemorrhage etiologies. Interventions included: non-pneumatic anti-shock garment (NASG) (N = 393), blood transfusion (N = 249), and referral to a higher-capacity facility (N = 131). After controlling for severity of disease and other confounders, women with abortion-related hemorrhage and shock had 78 percent decreased odds of receiving NASG (p < 0.001) and 77 percent decreased odds of receiving a blood transfusion (p < 0.001) compared to women with hemorrhage and shock from other etiologies. Our findings suggest that, in Tanzania, women with abortion-related hemorrhage received lower quality of care than women with other hemorrhage etiologies

Elucidating the phylodynamics of endemic rabies virus in eastern Africa using whole-genome sequencing

Many of the pathogens perceived to pose the greatest risk to humans are viral zoonoses, responsible for a range of emerging and endemic infectious diseases. Phylogeography is a useful tool to understand the processes that give rise to spatial patterns and drive dynamics in virus populations. Increasingly, whole-genome information is being used to uncover these patterns, but the limits of phylogenetic resolution that can be achieved with this are unclear. Here, whole-genome variation was used to uncover fine-scale population structure in endemic canine rabies virus circulating in Tanzania. This is the first whole-genome population study of rabies virus and the first comprehensive phylogenetic analysis of rabies virus in East Africa, providing important insights into rabies transmission in an endemic system. In addition, sub-continental scale patterns of population structure were identified using partial gene data and used to determine population structure at larger spatial scales in Africa. While rabies virus has a defined spatial structure at large scales, increasingly frequent levels of admixture were observed at regional and local levels. Discrete phylogeographic analysis revealed long-distance dispersal within Tanzania, which could be attributed to human-mediated movement, and we found evidence of multiple persistent, co-circulating lineages at a very local scale in a single district, despite on-going mass dog vaccination campaigns. This may reflect the wider endemic circulation of these lineages over several decades alongside increased admixture due to human-mediated introductions. These data indicate that successful rabies control in Tanzania could be established at a national level, since most dispersal appears to be restricted within the confines of country borders but some coordination with neighbouring countries may be required to limit transboundary movements. Evidence of complex patterns of rabies circulation within Tanzania necessitates the use of whole-genome sequencing to delineate finer scale population structure that can that can guide interventions, such as the spatial scale and design of dog vaccination campaigns and dog movement controls to achieve and maintain freedom from disease

Comparing methods of assessing dog rabies vaccination coverage in rural and urban communities in Tanzania

Rabies can be eliminated by achieving comprehensive coverage of 70% of domestic dogs during annual mass vaccination campaigns. Estimates of vaccination coverage are, therefore, required to evaluate and manage mass dog vaccination programs; however, there is no specific guidance for the most accurate and efficient methods for estimating coverage in different settings. Here, we compare post-vaccination transects, school-based surveys, and household surveys across 28 districts in southeast Tanzania and Pemba island covering rural, urban, coastal and inland settings, and a range of different livelihoods and religious backgrounds. These approaches were explored in detail in a single district in northwest Tanzania (Serengeti), where their performance was compared with a complete dog population census that also recorded dog vaccination status. Post-vaccination transects involved counting marked (vaccinated) and unmarked (unvaccinated) dogs immediately after campaigns in 2,155 villages (24,721 dogs counted). School-based surveys were administered to 8,587 primary school pupils each representing a unique household, in 119 randomly selected schools approximately 2 months after campaigns. Household surveys were conducted in 160 randomly selected villages (4,488 households) in July/August 2011. Costs to implement these coverage assessments were $12.01,$66.12, and $155.70 per village for post-vaccination transects, school-based, and household surveys, respectively. Simulations were performed to assess the effect of sampling on the precision of coverage estimation. The sampling effort required to obtain reasonably precise estimates of coverage from household surveys is generally very high and probably prohibitively expensive for routine monitoring across large areas, particularly in communities with high human to dog ratios. School-based surveys partially overcame sampling constraints, however, were also costly to obtain reasonably precise estimates of coverage. Post-vaccination transects provided precise and timely estimates of community-level coverage that could be used to troubleshoot the performance of campaigns across large areas. However, transects typically overestimated coverage by around 10%, which therefore needs consideration when evaluating the impacts of campaigns. We discuss the advantages and disadvantages of these different methods and make recommendations for how vaccination campaigns can be better monitored and managed at different stages of rabies control and elimination programs

Dr. Godfrey Mbaruku: A tribute and review of the life of a maternal health crusader in Tanzania

Dr. Godfrey Mbaruku, an obstetrician-gynecologist and one of Tanzania’s most dedicated maternal health researchers, passed away in September 2018. His professional career spanned over four decades, with the last decade of his life dedicated to maternal health research, advocacy and policy in Africa. We undertook a review of the key global milestones in maternal health policy, funding and research that took place during Dr. Mbaruku’s career until his untimely death in 2018. We then reflect on the progress of the maternal health agenda from 2018 to 2021 as lower middle income countries (LMICs) continue to strive to reach the sustainable development goals (SDGs) in the midst of a global pandemic. Dr. Godfrey Mbaruku’s commitment to improving maternal health in Tanzania through his advocacy and research contributions over his professional life will forever serve as foundational pillars for the ongoing global effort to reduce maternal mortality.   Le Dr Godfrey Mbaruku, obstétricien-gynécologue et l'un des chercheurs en santé maternelle les plus dévoués de Tanzanie, est décédé en septembre 2018. Sa carrière professionnelle a duré plus de quatre décennies, la dernière décennie de sa vie étant consacrée à la recherche, au plaidoyer et aux politiques en santé maternelle en Afrique. Nous avons entrepris un examen des principales étapes mondiales de la politique, du financement et de la recherche en matière de santé maternelle qui ont eu lieu au cours de la carrière du Dr Mbaruku jusqu'à sa mort prématurée en 2018. Nous réfléchissons ensuite aux progrès du programme de santé maternelle de 2018 à 2021 en tant que milieu inférieur. Les pays à revenu intermédiaire (PRFI) continuent de s'efforcer d'atteindre les objectifs de développement durable (ODD) au milieu d'une pandémie mondiale. L'engagement du Dr Godfrey Mbaruku à améliorer la santé maternelle en Tanzanie grâce à ses contributions de plaidoyer et de recherche au cours de sa vie professionnelle servira à jamais de piliers fondamentaux pour l'effort mondial en cours pour réduire la mortalité maternelle

Towards elimination of dog-mediated human rabies: experiences from implementing a large-scale demonstration project in Southern Tanzania

No abstract available

Bringing together emerging and endemic zoonoses surveillance: shared challenges and a common solution

Early detection of disease outbreaks in human and animal populations is crucial to the effective surveillance of emerging infectious diseases. However, there are marked geographical disparities in capacity for early detection of outbreaks, which limit the effectiveness of global surveillance strategies. Linking surveillance approaches for emerging and neglected endemic zoonoses, with a renewed focus on existing disease problems in developing countries, has the potential to overcome several limitations and to achieve additional health benefits. Poor reporting is a major constraint to the surveillance of both emerging and endemic zoonoses, and several important barriers to reporting can be identified: (i) a lack of tangible benefits when reports are made; (ii) a lack of capacity to enforce regulations; (iii) poor communication among communities, institutions and sectors; and (iv) complexities of the international regulatory environment. Redirecting surveillance efforts to focus on endemic zoonoses in developing countries offers a pragmatic approach that overcomes some of these barriers and provides support in regions where surveillance capacity is currently weakest. In addition, this approach addresses immediate health and development problems, and provides an equitable and sustainable mechanism for building the culture of surveillance and the core capacities that are needed for all zoonotic pathogens, including emerging disease threats

The epidemiology of residual Plasmodium falciparum malaria transmission and infection burden in an African city with high coverage of multiple vector control measures.

BACKGROUND In the Tanzanian city of Dar es Salaam, high coverage of long-lasting insecticidal nets (LLINs), larvicide application (LA) and mosquito-proofed housing, was complemented with improved access to artemisinin-based combination therapy and rapid diagnostic tests by the end of 2012. METHODS Three rounds of city-wide, cluster-sampled cross-sectional surveys of malaria parasite infection status, spanning 2010 to 2012, were complemented by two series of high-resolution, longitudinal surveys of vector density. RESULTS Larvicide application using a granule formulation of Bacillus thuringiensis var. israelensis (Bti) had no effect upon either vector density (P = 0.820) or infection prevalence (P = 0.325) when managed by a private-sector contractor. Infection prevalence rebounded back to 13.8 % in 2010, compared with <2 % at the end of a previous Bti LA evaluation in 2008. Following transition to management by the Ministry of Health and Social Welfare (MoHSW), LA consistently reduced vector densities, first using the same Bti granule in early 2011 [odds ratio (OR) (95 % confidence interval (CI)) = 0.31 (0.14, 0.71), P = 0.0053] and then a pre-diluted aqueous suspension formulation from mid 2011 onwards [OR (95 % CI) = 0.15 (0.07, 0.30), P ≪ 0.000001]. While LA by MoHSW with the granule formulation was associated with reduced infection prevalence [OR (95 % CI) = 0.26 (0.12, 0.56), P = 0.00040], subsequent liquid suspension use, following a mass distribution to achieve universal coverage of LLINs that reduced vector density [OR (95 % CI) = 0.72 (0.51, 1.01), P = 0.057] and prevalence [OR (95 % CI) = 0.80 (0.69, 0.91), P = 0.0013], was not associated with further prevalence reduction (P = 0.836). Sleeping inside houses with complete window screens only reduced infection risk [OR (95 % CI) = 0.71 (0.62, 0.82), P = 0.0000036] if the evenings and mornings were also spent indoors. Furthermore, infection risk was only associated with local vector density [OR (95 % CI) = 6.99 (1.12, 43.7) at one vector mosquito per trap per night, P = 0.037] among the minority (14 %) of households lacking screening. Despite attenuation of malaria transmission and immunity, 88 % of infected residents experienced no recent fever, only 0.4 % of these afebrile cases had been treated for malaria, and prevalence remained high (9.9 %) at the end of the study. CONCLUSIONS While existing vector control interventions have dramatically attenuated malaria transmission in Dar es Salaam, further scale-up and additional measures to protect against mosquito bites outdoors are desirable. Accelerated elimination of chronic human infections persisting at high prevalence will require active, population-wide campaigns with curative drugs