Distribution and molecular identification of ixodid ticks infesting cattle in Kilombero and Iringa Districts, Tanzania

BACKGROUND

Hard ticks infesting cattle are vectors of Tick-borne diseases that causes major public health problems and considerable socioeconomic losses to the livestock industry in tropical and subtropical countries. A repeated cross-sectional study was carried out by collecting ticks on cattle during the wet and dry seasons from January to August 2021 in order to determine hard tick prevalence, distribution, and abundance on cattle in Kilombero and Iringa Districts of Tanzania. The collected ticks were identified morphologically using published morphological keys under a stereomicroscope and confirmed by polymerase chain reaction (PCR) and sequencing.

RESULTS

Out of 740 examined cattle, 304, (41.08%) were infested with ticks. In total, 1,780 ticks were counted on one side of the animal's body and doubled, whereby resulting in a total of 3,560 ticks were recorded. Individual tick burden ranged from n = 2 to 82 ticks per animal, with a mean tick burden of n = 11.7 ± 0.68 per animal. A total of 1,889 ticks were collected from infected cattle including 109 additional ticks observed while collecting ticks based on the animal's posture when restrained to the ground. Out of 1,889 ticks, nine species from three genera were identified morphologically: 1,377 fit in the genus Rhipicephalus, 459 to the genus of Amblyomma, and 53 to the genus Hyalomma. Rhipicephalus microplus was the most prevalent (n = 909, 48.1%), followed by Rhipicephalus evertsi (n = 310, 16.4%), Amblyomma lepidum (n = 310, 16.4%), Rhipicephalus appendiculatus (n = 140, 7.4%), Amblyomma gemma (n = 120, 6.4%), Hyalomma rufipes (n = 50, 2.6%), Amblyomma variegatum (n = 29, 1.5%), Rhipicephalus decoloratus (n = 18, 1.0%), while the least common was Hyalomma albiparmatum (n = 3, 0.2%). Tick diversity was higher in Iringa compared to Kilombero District. Tick prevalence was higher in wet season (n = 148, 41.11%). Ticks were widely distributed in different parts of the host body, with the highest distribution on zone 4 (n = 1,060, 56.11%), which includes groin, flank, abdomen, and around inner thigh of the hind legs and the lowest distribution on zone 2 (n = 14, 0.74%), which includes the back surface of the body. Both Amblyomma lepidum and Rhipicephalus microplus species were found in all the five body zones, and with the highest proportions recorded on zone 4: A. lepidum (n = 209, 67.42%) and R. microplus (n = 714, 78.55%). The nine tick species identified morphologically were also confirmed using molecular methods. However, during sequencing, two species (Rhipicephalus appendiculatus and R. decoloratus) had poor quality sequences and were excluded from the sequence analysis. Sequencing results indicated high nucleotide identity (96-100%) with sequences available in GenBank and Barcode of Life Database (BOLD). The phylogenetic analysis of partial mitochondrial COI and 16S rRNA gene sequences of ticks were used to confirm the morphological identification.

CONCLUSION

The results showed a high burden of tick infestation on cattle, which could reduce animal production and potentially increase the risk of tick-borne diseases. Therefore, it is necessary to explore the epidemiological and molecular aspects of various tick species in other regions of Tanzania.

Integrating contact tracing and whole-genome sequencing to track the elimination of dog-mediated rabies: an observational and genomic study

Background

Dog-mediated rabies is endemic across Africa causing thousands of human deaths annually. A One Health approach to rabies is advocated, comprising emergency post-exposure vaccination of bite victims and mass dog vaccination to break the transmission cycle. However, the impacts and cost-effectiveness of these components are difficult to disentangle.

Methods

We combined contact tracing with whole-genome sequencing to track rabies transmission in the animal reservoir and spillover risk to humans from 2010-2020, investigating how the components of a One Health approach reduced the disease burden and eliminated rabies from Pemba Island, Tanzania. With the resulting high-resolution spatiotemporal and genomic data we inferred transmission chains and estimated case detection. Using a decision tree model we quantified the public health burden and evaluated the impact and cost-effectiveness of interventions over a ten-year time horizon.

Results

We resolved five transmission chains co-circulating on Pemba from 2010 that were all eliminated by May 2014. During this period, rabid dogs, human rabies exposures and deaths all progressively declined following initiation and improved implementation of annual islandwide dog vaccination. We identified two introductions to Pemba in late 2016 that seeded re-emergence after dog vaccination had lapsed. The ensuing outbreak was eliminated in October 2018 through reinstated islandwide dog vaccination. While post-exposure vaccines were projected to be highly cost-effective ($256 per death averted), only dog vaccination interrupts transmission. A combined One Health approach of routine annual dog vaccination together with free post-exposure vaccines for bite victims, rapidly eliminates rabies, is highly cost-effective ($1657 per death averted) and by maintaining rabies freedom prevents over 30 families from suffering traumatic rabid dog bites annually on Pemba island.

Conclusions

A One Health approach underpinned by dog vaccination is an efficient, cost-effective, equitable and feasible approach to rabies elimination, but needs scaling up across connected populations to sustain the benefits of elimination, as seen on Pemba, and for similar progress to be achieved elsewhere.

Funding

Wellcome [207569/Z/17/Z, 095787/Z/11/Z, 103270/Z/13/Z], the UBS Optimus Foundation, the Department of Health and Human Services of the National Institutes of Health [R01AI141712] and the DELTAS Africa Initiative [Afrique One-ASPIRE/DEL-15-008] comprising a donor consortium of the African Academy of Sciences (AAS), Alliance for Accelerating Excellence in Science in Africa (AESA), the New Partnership for Africa's Development Planning and Coordinating (NEPAD) Agency, Wellcome [107753/A/15/Z], Royal Society of Tropical Medicine and Hygiene Small Grant 2017 [GR000892] and the UK government. The rabies elimination demonstration project from 2010-2015 was supported by the Bill & Melinda Gates Foundation [OPP49679]. Whole-genome sequencing was partially supported from APHA by funding from the UK Department for Environment, Food and Rural Affairs (Defra), Scottish government and Welsh government under projects SEV3500 & SE0421.

A global analysis of One Health Networks and the proliferation of One Health collaborations

There has been a renewed focus on threats to the human-animal-environment interface as a result of the COVID-19 pandemic, and investments in One Health collaborations are expected to increase. Efforts to monitor the development of One Health Networks (OHNs) are essential to avoid duplication or misalignment of investments. This Series paper shows the global distribution of existing OHNs and assesses their collective characteristics to identify potential deficits in the ways OHNs have formed and to help increase the effectiveness of investments. We searched PubMed, Google, Google Scholar, and relevant conference websites for potential OHNs and identified 184 worldwide for further analysis. We developed four case studies to show important findings from our research and exemplify best practices in One Health operationalisation. Our findings show that, although more OHNs were formed in the past 10 years than in the preceding decade, investment in OHNs has not been equitably distributed; more OHNs are formed and headquartered in Europe than in any other region, and emerging infections and novel pathogens were the priority focus area for most OHNs, with fewer OHNs focusing on other important hazards and pressing threats to health security. We found substantial deficits in the OHNs collaboration model regarding the diversity of stakeholder and sector representation, which we argue impedes effective and equitable OHN formation and contributes to other imbalances in OHN distribution and priorities. These findings are supported by previous evidence that shows the skewed investment in One Health thus far. The increased attention to One Health after the COVID-19 pandemic is an opportunity to focus efforts and resources to areas that need them most. Analyses, such as this Series paper, should be used to establish databases and repositories of OHNs worldwide. Increased attention should then be given to understanding existing resource allocation and distribution patterns, establish more egalitarian networks that encompass the breadth of One Health issues, and serve communities most affected by emerging, re-emerging, or endemic threats at the human-animal-environment interface.

Non-tuberculous mycobacterial pulmonary disease: Awareness survey of front-desk healthcare workers in Northern Tanzania

Over the past decade, there have been increasing reports of non-tuberculous mycobacteria (NTM) species being implicated in tuberculosis (TB) treatment failure or misdiagnosed as TB. Inadequate awareness of NTM pulmonary disease among healthcare workers (HCWs) may contribute to a low index of suspicion for patients presenting to their hospitals. In this study, we assessed the awareness of NTM pulmonary disease (NTM-PD) among front desk HCWs in Northern Tanzania. A cross-sectional descriptive survey was carried out among front desk HCWs in four administrative regions of Northern Tanzania. A standardized questionnaire was administered to consented participants from four clusters; clinicians, laboratory scientists, nurses, and pharmacists serving TB patients from Regional and District Health Facilities. Each participant was asked a set of questions, scored and the total score for each participant was determined. An awareness score was used to measure the level of awareness. The average score for all participants was estimated including the 95% confidence interval (CI). The overall awareness score was 24.1%, 95% CI 22.0-26.2%. History of training, experience in TB care, level of health facilities, age group, and setting were found to be statistically associated with the level of awareness of study participants. More than two-thirds (67%) of participants believe that pulmonary NTM and TB are clinically similar and 60% are not aware that AFB Microscopy cannot distinguish between the two. Only 13% of participants could mention at least one risk factor for NTM pulmonary disease. The level of awareness of NTM pulmonary disease was poor among HCWs in the surveyed TB clinics. National TB Programs are advised to include a topic on NTM in various on-job TB training packages for HCWs.

Rabies shows how scale of transmission can enable acute infections to persist at low prevalence

How acute pathogens persist and what curtails their epidemic growth in the absence of acquired immunity remains unknown. Canine rabies is a fatal zoonosis that circulates endemically at low prevalence among domestic dogs in low- and middle-income countries. We traced rabies transmission in a population of 50,000 dogs in Tanzania from 2002 to 2016 and applied individual-based models to these spatially resolved data to investigate the mechanisms modulating transmission and the scale over which they operate. Although rabies prevalence never exceeded 0.15%, the best-fitting models demonstrated appreciable depletion of susceptible animals that occurred at local scales because of clusters of deaths and dogs already incubating infection. Individual variation in rabid dog behavior facilitated virus dispersal and cocirculation of virus lineages, enabling metapopulation persistence. These mechanisms have important implications for prediction and control of pathogens that circulate in spatially structured populations.

Development of Dog Vaccination Strategies to Maintain Herd Immunity against Rabies

Human rabies can be prevented through mass dog vaccination campaigns; however, in rabies endemic countries, pulsed central point campaigns do not always achieve the recommended coverage of 70%. This study describes the development of a novel approach to sustain high coverage based on decentralized and continuous vaccination delivery. A rabies vaccination campaign was conducted across 12 wards in the Mara region, Tanzania to test this approach. Household surveys were used to obtain data on vaccination coverage as well as factors influencing dog vaccination. A total 17,571 dogs were vaccinated, 2654 using routine central point delivery and 14,917 dogs using one of three strategies of decentralized continuous vaccination. One month after the first vaccination campaign, coverage in areas receiving decentralized vaccinations was higher (64.1, 95% Confidence Intervals (CIs) 62.1-66%) than in areas receiving pulsed vaccinations (35.9%, 95% CIs 32.6-39.5%). Follow-up surveys 10 months later showed that vaccination coverage in areas receiving decentralized vaccinations remained on average over 60% (60.7%, 95% CIs 58.5-62.8%) and much higher than in villages receiving pulsed vaccinations where coverage was on average 32.1% (95% CIs 28.8-35.6%). We conclude that decentralized continuous dog vaccination strategies have the potential to improve vaccination coverage and maintain herd immunity against rabies.

Use of a Participatory Method for Community-Based Brucellosis Control Design in Agro-Pastoral Areas in Tanzania

Brucellosis is widespread in both humans and livestock in many developing countries. The authors have performed a series of epidemiological studies on brucellosis in agro-pastoral areas in Tanzania since 2015, with the aim of the disease control. Previously, the potential of a community-based brucellosis control initiative, which mainly consisted of the sale of cattle with experience of abortion and vaccinating calves, was assessed as being effective and acceptable based on a quantitative approach. This study was conducted to investigate the feasibility of community-based brucellosis control program using participatory rural appraisals (PRAs) and key-informant interviews. Four PRAs were performed together with livestock farmers and livestock and medical officers in 2017. In the PRAs, qualitative information related to risky behaviors for human infection, human brucellosis symptoms, willingness to sell cattle with experience of abortion, and willingness to pay for calf vaccination were collected, and a holistic approach for a community-based disease control project was planned. All of the communities were willing to implement disease control measures. To avoid human infection, education, especially for children, was proposed to change risky behaviors. The findings of this study showed that community-based disease control measures are promising.

Investigating the Efficacy of a Canine Rabies Vaccine Following Storage Outside of the Cold-Chain in a Passive Cooling Device

Background: Thermostable vaccines greatly improved the reach and impact of large-scale programmes to eliminate infectious diseases such as smallpox, polio, and rinderpest. A study from 2015 demonstrated that the potency of the Nobivac® Rabies vaccine was not impacted following experimental storage at 30°C for 3 months. Whether the vaccine would remain efficacious following storage under more natural, fluctuating temperature conditions remains unknown. We carried out a randomised controlled non-inferiority trial to compare serological responses in dogs following vaccination with doses stored under cold chain conditions with those stored within a locally made Passive Cooling Device ("Zeepot") under fluctuating temperature conditions. Materials and Methods: Nobivac® Rabies vaccine was stored under either cold-chain conditions or within the Zeepot for 2 months. Daily ambient temperatures and temperatures within the Zeepot were recorded every 3 h. Following storage, 412 domestic dogs were randomly assigned to receive either cold-chain or Zeepot stored Nobivac® Rabies vaccine. Baseline and day 28-post vaccination blood samples were collected. Serological analysis using the Fluorescent Antibody Virus Neutralisation assay was carried out with a threshold of 0.5 IU/ml to determine seroconversion. In addition, the impact of dog Body Condition Score, sex, and age on seroconversion was examined. Results: The serological response of dogs vaccinated using Nobivac® Rabies vaccine stored within the Zeepot was not inferior to the response of dogs vaccinated using cold-chain stored vaccine (z = 1.1, df = 313, p-value = 0.25). Indeed, the 28-day post-vaccination group geometric mean titre was 1.8 and 2.0 IU/ml for cold-chain vs. non-cold-chain storage, respectively. Moreover, the percentage of dogs that seroconverted in each arm was almost identical (85%). There was a positive linear trend between Body Condition Score (O.R. 2.2, 95% CI: 1.1-5.1) and seroconversion, suggesting dogs of poor condition may not respond as expected to vaccination. Conclusions: Our study demonstrated the potency of Nobivac® Rabies vaccine is not impacted following storage under elevated fluctuating temperatures within a Zeepot. These results have potentially exciting applications for scaling up mass dog vaccination programmes in low-and-middle income countries, particularly for hard-to-reach populations with limited access to power and cold-chain vaccine storage.

Combining Multiple Assays Improves Detection and Serotyping of Foot-and-Mouth Disease Virus. A Practical Example with Field Samples from East Africa

Multiple serotypes and topotypes of foot-and-mouth disease virus (FMDV) circulate in endemic areas, posing considerable impacts locally. In addition, introductions into new areas are of great concern. Indeed, in recent years, multiple FMDV outbreaks, caused by topotypes that have escaped from their original areas, have been recorded in various parts of the world. In both cases, rapid and accurate diagnosis, including the identification of the serotype and topotype causing the given outbreaks, plays an important role in the implementation of the most effective and appropriate measures to control the spread of the disease. In the present study, we describe the performance of a range of diagnostic and typing tools for FMDV on a panel of vesicular samples collected in northern Tanzania (East Africa, EA) during 2012–2018. Specifically, we tested these samples with a real-time RT-PCR targeting 3D sequence for pan-FMDV detection; an FMDV monoclonal antibody-based antigen (Ag) detection and serotyping ELISA kit; virus isolation (VI) on LFBKαVβ6 cell line; and a panel of four topotype-specific real-time RT-PCRs, specifically tailored for circulating strains in EA. The 3D real-time RT-PCR showed the highest diagnostic sensitivity, but it lacked typing capacity. Ag-ELISA detected and typed FMDV in 71% of sample homogenates, while VI combined with Ag-ELISA for typing showed an efficiency of 82%. The panel of topotype-specific real-time RT-PCRs identified and typed FMDV in 93% of samples. However, the SAT1 real-time RT-PCR had the highest (20%) failure rate. Briefly, topotype-specific real-time RT-PCRs had the highest serotyping capacity for EA FMDVs, although four assays were required, while the Ag-ELISA, which was less sensitive, was the most user-friendly, hence suitable for any laboratory level. In conclusion, when the four compared tests were used in combination, both the diagnostic and serotyping performances approached 100%.

Quantitative evaluation of the infection dynamics of bovine brucellosis in Tanzania

Brucellosis is endemic in Tanzania. A cross-sectional study was conducted at 17 cattle farms in agro-pastoral areas in Tanzania to identify risk factors associated with the within-farm prevalence of bovine brucellosis and to quantitatively assess the infection dynamics through disease modelling. Cattle blood sampling and interviews with farmers using a structured questionnaire were conducted. A total of 673 serum samples were screened using the Rose-Bengal plate test (RBPT), and sero-positivity of RBPT-positive samples was confirmed using a competitive enzyme-linked immunosorbent assay. Zero-inflated binomial regression was performed for univariable and multivariable risk factor analyses of within-farm prevalence. Several susceptible-infectious (SI) models were compared based on deviance information criteria, and age-dependent force of infection (FOI) was measured using age-specific prevalence data for the 10 infection-positive farms. Using the diagnoses of cows on the 17 farms, the basic reproduction number, R₀, was also calculated. The farm-level prevalence and animal-level adjusted prevalence were 58.8 % (10/17, 95 % confidence interval: 33.5-80.6 %) and 7.0 % (28/673, 95 % credible interval: 5.7-8.4 %), respectively. The risk factor for high within-farm prevalence was introduction of cattle from other herds. A mathematical model with constant FOI showed the annual probability of infection as 1.4 % (95 % credible interval: 1.0 %-2.0 %). The R₀ was 1.07. The constant FOI could have been due to the predominant mode of infection being transmission of Brucella from contaminated aborted materials during grazing. Direct purchase of infected cattle could facilitate efficient transmission between susceptible animals through abortion.

Determinants of treatment-seeking behavior during self-reported febrile illness episodes using the socio-ecological model in Kilombero District, Tanzania

Background

Febrile diseases in Sub-Saharan Africa cause acute and chronic illness. Co-infections are common and these diseases have a complex etiology that includes zoonoses. For the implementation of appropriate treatment and control strategies, determinants of lay treatment-seeking behavior by the affected communities need to be understood. The objective of this study was to explore, using the socio-ecological model, the determinants of treatment-seeking actions among self-identified febrile illness cases in the Kilombero District of Tanzania.

Methods

Thirty-nine in-depth interviews were conducted with 28 men and 11 women in three villages in Kilombero district. These villages were purposively selected due to malaria endemicity in the area, animal husbandry practices, and proximity to livestock-wildlife interaction, all risk factors for contracting febrile zoonotic infections. Thematic analysis was conducted on the interviews to identify the key determinants of treatment-seeking actions.

Results

Study participants attributed febrile illnesses to malaria, typhoid and urinary tract infections. Treatment-seeking behavior was an iterative process, influenced by individual, socio-cultural, ecological and policy factors. Age, expendable income, previous history with a febrile illness, perceptions on disease severity, seasonal livelihood activities and access to timely healthcare were some of the determinants. Self-treatment with pharmaceutical drugs and herbs was usually the initial course of action. Formal healthcare was sought only when self-treatment failed and traditional healers were consulted after the perceived failure of conventional treatment. Delays in seeking appropriate health care and the consultation of medically unqualified individuals was very common.

Conclusion

The results imply that treatment-seeking behavior is shaped by multiple factors across all levels of the socio-ecological model. Public policy efforts need to focus on facilitating prompt health care seeking through community education on the complicated etiology of febrile illnesses. Improved access to timely treatment and better differential diagnostics by health professionals are essential to ensure correct and appropriate treatment and to reduce reliance of patients on unqualified persons.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11027-w.

Lay attitudes and misconceptions and their implications for the control of brucellosis in an agro-pastoral community in Kilombero district, Tanzania

Brucellosis is a priority zoonotic disease in Tanzania that causes ill-health in people and affects livestock productivity. Inadequate awareness and behavior risking transmission can impede control efforts. We conducted a cross-sectional survey of 333 livestock owners in three villages in the Kilombero district, Tanzania, to understand their awareness, knowledge and behavior associated with brucellosis. Six Focus Group Discussions (FGDs), two in each village, were conducted, as well as an additional FGD with male herders from one of the villages. Factors associated with knowledge on brucellosis, food consumption and animal husbandry behavior risking transmission of this disease, were identified using generalized linear models. Predictors for knowledge of brucellosis were being male and having a higher educational level, while age was positively associated with a higher level of knowledge. Faith and ethnicity were associated with the performance of practices risking transmission. Following traditional religion and belonging to the Wamaasai ethnicity significantly increased the odds of carrying out these practices. Qualitative analysis gave insight into risk practices and reasoning. Of the 333 respondents, 29% reported that they had experienced abortions in their herds, 14% witnessed retained placentas, and 8% had seen still-births in their cattle within the previous year. However, survey results also showed that only 7.2% of participants had heard about brucellosis as a disease in livestock. Of those who had heard about brucellosis in livestock, 91% associated abortions with it and 71% knew that humans can get infected through raw milk consumption. People overwhelmingly attributed symptoms and transmission of brucellosis in livestock to infection with trypanosomiasis and to supernatural reasons instead. In the community, consumption of raw milk was valued and handling of aborted material was not considered a risk for infection. This agro-pastoralist community holds on to long-held beliefs and practices and lacks understanding of the biomedical concept of brucellosis. Transmission routes and symptoms of brucellosis in humans and livestock are completely unknown. The disparity between risk perception and actual transmission risk related to animal handling and consumption of animal products presents a challenge for disease awareness communication. This study recommends focused community engagement and sensitization to address the limited awareness and misconceptions among agro-pastoralists.

Trends in extrapulmonary TB cases at three teaching hospitals in Ghana, 2008-2017

SETTING

Three teaching hospitals in Ghana.

OBJECTIVE

To elucidate trends in demographics, clinical characteristics and treatment outcomes in extrapulmonary TB (EPTB) patients.

DESIGN

This was a retrospective study involving the review and comparison of EPTB and pulmonary TB (PTB) data from 1 January 2008 to 31 December 2017 in TB registers and treatment cards.

RESULTS

Of 15,392 TB cases, 4607 (30%) were EPTB, including 4477/4607 (97%) new cases. There were 2,679/4607 (58%) males and the age range was 0.3 to 96 years. Pleural TB (1021/4607, 22%) was the most common. Treatment success rates for EPTB and PTB were respectively 72% and 84%. HIV positivity was high among patients with disseminated/miliary TB (429/779, 55%) and TB meningitis (242/526, 46%). To note, disseminated/miliary TB (χ2 = 33.53, P < 0.0001) increased, whereas TB meningitis (χ2 = 19.43, P < 0.0001) decreased over the 10-year period. Mortality among EPTB patients was associated with increasing age (⩾25 years), disseminated/miliary TB, TB meningitis and HIV positivity.

CONCLUSIONS

There is male preponderance for both EPTB and PTB in Ghana. Increasing age, disseminated/ miliary TB, TB meningitis and HIV are risk factors for mortality among EPTB patients. This emphasises the need for public education on the risk factors for EPTB and preventive strategies.

Student and Institutional Achievements during an OIE Veterinary Education Twinning Project Collaboration between Sokoine University of Agriculture and Kansas State University

This collaborative partnership aimed to enhance the quality of veterinary education at both Sokoine University of Agriculture (SUA), College of Veterinary Medicine and Biomedical Sciences (Tanzania), and Kansas State University (KSU), College of Veterinary Medicine (United States), by facilitating exchange of knowledge, experience, and ideas. One project objective was to integrate the World Organisation for Animal Health (OIE) Guidelines on Veterinary Education Core Curriculum into the SUA education program so veterinary graduates would be equipped with the minimum competencies needed to support their National Veterinary Services (OIE Day 1 Competencies). Curriculum mapping revealed that partners addressed different OIE Day 1 Competencies to varying degrees and they had complementary strengths and weaknesses. The partners' practical and educational experiences were also complementary, providing each opportunities to learn from the other and a solid basis for long-term mutually beneficial collaboration. Through structured exchanges, the collaboration allowed SUA and KSU students and faculty to broaden their perspectives by exposing them to veterinary medicine, culture, ecosystems, teaching environments, and farming systems in each other's country. Visiting faculties and students from both universities were exposed to different livestock systems, varying dynamics at the human-livestock-wildlife interface, different teaching systems, and a veterinary profession with a different culture and focus than that in their own country. Students and faculty learned about the relative social and economic importance of different types of animal production in each country and their influence on veterinary education priorities. Partnership outcomes include a continuing professional development course at SUA for private and public sector veterinarians and a clinical club to expose students at both colleges to a broader range of clinical cases and knowledge.

Fruit bats in flight: a look into the movements of the ecologically important Eidolon helvum in Tanzania

BACKGROUND

Many ecologically important plants are pollinated or have their seeds dispersed by fruit bats, including the widely distributed African straw-colored fruit bats (Eidolon helvum). Their ability to fly long distances makes them essential for connecting plant populations across fragmented landscapes. While bats have been implicated as a reservoir of infectious diseases, their role in disease transmission to humans is not well understood. In this pilot study, we tracked E. helvum to shed light on their movement patterns in Tanzania and possible contact with other species.

METHODS

Tracking devices were deployed on 25 bats captured in the Morogoro Municipal and Kilombero District area near the Udzungwa Mountains of Tanzania. Nightly flight patterns, areas corresponding to foraging bouts and feeding roosts, and new day roosts were determined from bat movement data and characterized according to their proximity to urban built-up and protected areas. Sites for additional environmental surveillance using camera traps were identified via tracking data to determine species coming in contact with fruits discarded by bats.

RESULTS

Tracking data revealed variability between individual bat movements and a fidelity to foraging areas. Bats were tracked from one to six nights, with a mean cumulative nightly flight distance of 26.14 km (min: 0.33, max: 97.57) based on data from high-resolution GPS tags. While the majority of their foraging locations were in or near urban areas, bats also foraged in protected areas, of which the Udzungwa Mountains National Park was the most frequented. Camera traps in fruit orchards frequented by tracked bats showed the presence of multiple species of wildlife, with vervet monkeys (Chlorocebus pygerythrus) observed as directly handling and eating fruit discarded by bats.

CONCLUSIONS

Because we observed multiple interactions of animals with fruits discarded by bats, specifically with vervet monkeys, the possibility of disease spillover risk exists via this indirect pathway. With flight distances of up to 97 km, however, the role of E. helvum in the seed dispersal of plants across both protected and urban built-up areas in Tanzania may be even more important, especially by helping connect increasingly fragmented landscapes during this Anthropocene epoch.

Seroprevalence and risk factors for human brucellosis in agro-pastoral areas in Tanzania

Background: Brucellosis is an endemic zoonosis in Tanzania. This study was conducted to investigate the seroprevalence of human brucellosis and its risk factors in agro-pastoral areas in Morogoro Region, Tanzania. Methods: Questionnaire survey and blood sampling were conducted from January to February 2018 at four villages. Anyone living in the villages and wished to participate were involved. Competitive ELISA was used for diagnosis. Risk factor analysis for sero-positivity in human and analysis for the association of sero-positivity between cattle and human within each farm were conducted, using the data of farm-level bovine brucellosis status from our bovine brucellosis research performed in 2016. Results: The seroprevalence was 33.3% (44/132). In univariable analysis, the Maasai were significantly more sero-positive (56.5%) than other tribes (28.4%) (OR = 3.23, 95% CI: 1.28–8.41). Drinking raw milk was a risk factor in both univariable and multivariable analyses (OR = 3.97, 95% CI: 1.61–10.20). A negative association between sero-positivity in cattle and human within each farm was found (p<0.01). The Maasai performed more risk-taking behaviours for human infection than other tribes: drinking raw milk (p<0.01) or blood (p<0.01) and helping delivery of cattle with bare hands (p=0.03). Conclusions: The Maasai were at high risk of human brucellosis. More detailed survey and educational interventions are urgently needed.

Subnational operationalization of One Health: lessons from the establishment of One Health rapid response teams in Tanzania

In 2018, Tanzania launched the One Health Coordination Desk (OHCD) in a country that operates a centralized public health system with limited privatization. In contrast, the animal health system is decentralized, with huge reliance on privatization. Subnational level implementation of health services are sometimes at odds with national-level planning due to inherent challenges. To bridge these gaps, One Health rapid response teams (OHRRTs) were set up and pilot tested in selected districts and regions of Tanzania. These teams serve the community directly through the delivery of community-oriented One Health activities. We discuss the OHRRT set-up process as an example of good practice for adoption in developing economies.

Developing a Global One Health Workforce: The "Rx One Health Summer Institute" Approach

The One Health approach has gained support across a range of disciplines; however, training opportunities for professionals seeking to operationalize the interdisciplinary approach are limited. Academic institutions, through the development of high-quality, experiential training programs that focus on the application of professional competencies, can increase accessibility to One Health education. The Rx One Health Summer Institute, jointly led by US and East African partners, provides a model for such a program. In 2017, 21 participants representing five countries completed the Rx One Health program in East Africa. Participants worked collaboratively with communities neighboring wildlife areas to better understand issues impacting human and animal health and welfare, livelihoods, and conservation. One Health topics were explored through community engagement and role-playing exercises, field-based health surveillance activities, laboratories, and discussions with local experts. Educational assessments reflected improvements in participants' ability to apply the One Health approach to health and disease problem solving, as well as anticipate cross-sectoral challenges to its implementation. The experiential learning method, specifically the opportunity to engage with local communities, proved to be impactful on participants' cultural awareness. The Rx One Health Summer Institute training model may provide an effective and implementable strategy by which to contribute to the development of a global One Health workforce.

Serological and molecular evidence of Brucella species in the rapidly growing pig sector in Kenya

BACKGROUND

Brucellosis is an emerging yet neglected zoonosis that has been reported in Kenya. Epidemiological data on brucellosis in ruminants is readily accessible; however, reports on brucellosis in pigs remain limited. This study sought to detect Brucella infection in pig serum by both serological and molecular techniques. Serum from 700 pigs randomly collected at a centralized abattoir in Nairobi region, Kenya were screened in parallel, using both Rose Bengal Test (RBT) and competitive Enzyme-Linked Immuno-sorbent Assay (cELISA) for antibodies against Brucella spp. All sera positive by RBT and 16 randomly selected negative samples were further tested using conventional PCR targeting bcsp31 gene and real-time PCR (RT-PCR) assays targeting IS711 and bcsp31 genes.

RESULTS

A prevalence of 0.57% (n = 4/700) was estimated using RBT; none of these samples was positive on cELISA. All RBT positive sera were also positive by both PCRs, while two sero-negative samples also tested positive on RT-PCR (n = 6/20). Brucella abortus was detected in four out of the six PCR positive samples through a real-time multiplex PCR.

CONCLUSION

The detection of antibodies against Brucella spp. and DNA in serum from slaughterhouse pigs confirm the presence of Brucella in pigs. Therefore, investigation of the epidemiology and role of pigs in the transmission of brucellosis in Kenya is needed. Further targeted studies would be useful to systematically quantify and identify the spp. of Brucella in pigs.

Reproduction of East-African bats may guide risk mitigation for coronavirus spillover

BACKGROUND

Bats provide important ecosystem services; however, current evidence supports that they host several zoonotic viruses, including species of the Coronaviridae family. If bats in close interaction with humans host and shed coronaviruses with zoonotic potential, such as the Severe Acute Respiratory Syndrome virus, spillover may occur. Therefore, strategies aiming to mitigate potential spillover and disease emergence, while supporting the conservation of bats and their important ecological roles are needed. Past research suggests that coronavirus shedding in bats varies seasonally following their reproductive cycle; however, shedding dynamics have been assessed in only a few species, which does not allow for generalization of findings across bat taxa and geographic regions.

METHODS

To assess the generalizability of coronavirus shedding seasonality, we sampled hundreds of bats belonging to several species with different life history traits across East Africa at different times of the year. We assessed, via Bayesian modeling, the hypothesis that chiropterans, across species and spatial domains, experience seasonal trends in coronavirus shedding as a function of the reproductive cycle.

RESULTS

We found that, beyond spatial, taxonomic, and life history differences, coronavirus shedding is more expected when pups are becoming independent from the dam and that juvenile bats are prone to shed these viruses.

CONCLUSIONS

These findings could guide policy aimed at the prevention of spillover in limited-resource settings, where longitudinal surveillance is not feasible, by identifying high-risk periods for coronavirus shedding. In these periods, contact with bats should be avoided (for example, by impeding or forbidding people access to caves). Our proposed strategy provides an alternative to culling - an ethically questionable practice that may result in higher pathogen levels - and supports the conservation of bats and the delivery of their key ecosystem services.

Seasonal movements and habitat use of African buffalo in Ruaha National Park, Tanzania

Background

Assessing wildlife movements and habitat use is important for species conservation and management and can be informative for understanding population dynamics. The African buffalo (Syncerus caffer) population of Ruaha National Park, Tanzania has been declining, and little was known about the movement, habitat selection, and space use of the population, which is important for understanding possible reasons behind the decline. A total of 12 African buffalo cows from four different herds were collared with satellite transmitters. Movements were assessed over 2 years from 11 animals.

Results

The space use of the individual collared buffaloes as an approximation of the 95% home range size estimated using Brownian bridge models, ranged from 73 to 601 km². The estimated home ranges were larger in the wet season than in the dry season. With the exception of one buffalo all collared animals completed a wet season migration of varying distances. A consistent pattern of seasonal movement was observed with one herd, whereas the other herds did not behave the same way in the two wet seasons that they were tracked. Herd splitting and herd switching occurred on multiple occasions. Buffaloes strongly associated with habitats near the Great Ruaha River in the dry season and had little association to permanent water sources in the wet season. Daily movements averaged 4.6 km (standard deviation, SD = 2.6 km), with the longest distances traveled during November (mean 6.9 km, SD = 3.6 km) at the end of the dry season and beginning of the wet season. The shortest daily distances traveled occurred in the wet season in April–June (mean 3.6 km, SD = 1.6–1.8 km).

Conclusion

The Great Ruaha River has experienced significant drying in the last decades due to water diversions upstream, which likely has reduced the suitable range for buffaloes. The loss of dry season habitat due to water scarcity has likely contributed to the population decline of the Ruaha buffaloes.

Implementing One Health approaches to confront emerging and re-emerging zoonotic disease threats: lessons from PREDICT

Recurring outbreaks of emerging and re-emerging zoonoses, such as Ebola virus disease, avian influenza, and Nipah virus, serve as a reminder that the health of humans, animals, and the environment are interconnected and that early response to emerging zoonotic pathogens requires a coordinated, interdisciplinary, cross-sectoral approach. As our world becomes increasingly connected, emerging diseases pose a greater threat, requiring coordination at local, regional, and global levels. One Health is a multisectoral, transdisciplinary, and collaborative approach promoted to more effectively address these complex health threats. Despite strong advocacy for One Health, challenges for practical implementation remain. Here we discuss the value of the One Health approach for addressing global health challenges. We also share strategies applied to achieve successful outcomes through the USAID Emerging Pandemic Threats Program PREDICT project, which serve as useful case studies for implementing One Health approaches. Lastly, we explore methods for promoting more formal One Health implementation to capitalize on the added value of shared knowledge and leveraged resources.

PO 8573 RESEARCH, MENTORSHIP AND SUSTAINABLE DEVELOPMENT: IS RETIREMENT AGE A HURDLE TO RESEARCH SUSTAINABILITY IN AFRICA?

Background

Retirement age in most of sub-Saharan Africa is between 55 and 60 years, even in academic and research institutions. There is no mechanism to retain even the few most experienced and outstanding among them. There is evidence that institutions retaining experienced researchers access better large research grants.

Methods

We conducted literature review and shared views and experiences among peer research scientists

Results

Most African scientists obtain their first degrees aged 25–30 years. Economic needs compounded with work experience requirements for PhD studies delay their research career development such that most PhD graduates are 40–50 years of age. However, unlike in the developed world where the majority acquire their PhDs in their late 20’s or early 30’s, there is no mechanism to retain them longer at work to maximise their contributions to scientific developments. Instead, African scientists are forced to retire young at 60 years of age. On the contrary, developed countries scientists graduate earlier, work longer and have retention mechanisms even after retirement. African countries do not consider retaining even the few who have demonstrated outstanding performance. Consequently, outstanding research scientists retire at the time when they are needed most. They seek and get jobs abroad or in externally owned projects (brain drain). Their decade or so of work, generates more resources abroad, depriving Africa of resource generating capacity. Secondly, retiring at the height of their performance is economically counterproductive. Thirdly, this affects negatively the career development of young scientists for lack of experienced supervisors and mentors.

Conclusion

Africa must rethink the retirement age of its research scientists and create incentives to retain outstanding research scientists who reach retirement age. This is urgently needed to stop brain drain, contribute to economic development, and accelerate ongoing efforts to build sustainable research capacity and mentorship programmes in Africa.

Herd-level risk factors associated with Brucella sero-positivity in cattle, and perception and behaviours on the disease control among agro-pastoralists in Tanzania

Brucellosis is endemic in Tanzania, particularly in agro-pastoral areas. This study investigated the herd-level sero-prevalence and risk factors for Brucella sero-positivity in cattle, and perception and behaviours associated with brucellosis control among agro-pastoralists in Morogoro Region, Tanzania. A cross-sectional study involving herd milk diagnosis by indirect enzyme-linked immunosorbent assay and questionnaire survey was conducted in 124 farms. Questions included potential risk factors, knowledge of brucellosis, willingness-to-pay for cattle vaccination, and item count technique (ICT) for selling behaviour of cows that experienced abortion. Risk factor analysis for Brucella sero-positivity in cattle and analysis of factors associated with willingness-to-pay were conducted using classical tests and generalised linear models. Most farmers had little knowledge about brucellosis (disease name: 13.7%, symptoms: 3.2%, transmission from cattle to human: 2.4%, and Brucella vaccine: 2.4%). The proportion of Brucella sero-positive herd was 44.4% (55/124, 95%CI: 35.5-53.5). No risk factors for Brucella sero-positivity were identified; however, using a veterinary service was identified as a preventive factor (OR = 0.39, 95%CI: 0.18-0.84, p =  0.02). For scenarios of vaccinating all cattle and only calves, 59.7% and 89.5% of farmers were willing to pay for vaccination, respectively. Being a Maasai tribe member was a hesitating factor for vaccinating all cattle (OR = 0.39, 95%CI: 0.19-0.83, p =  0.01) and using a veterinary service was an encouraging factor for vaccinating calves (OR = 4.0, 95%CI: 1.2-13.0, p =  0.02). The ICT found that 45.1% of farmers sold cows that experienced abortion. This estimate was not statistically different from that obtained by direct questioning (34.1%, SE = 7.5%, binomial p value = 0.27, factor score = 1.32), suggesting that farmers did not hesitate to sell such cows. The Maasai conducted more risky behaviours for human infection such as drinking raw milk (p = 0.06) or blood (p <  0.01) and helping delivery with bare hands (p = 0.03) than other tribes. Community-based brucellosis control programmes with calf vaccination may be feasible in the study areas. A One Health approach including the promotion of health education and expansion of veterinary services is crucial for disease control.

Waves of endemic foot-and-mouth disease in eastern Africa suggest feasibility of proactive vaccination approaches

Livestock production in Africa is key to national economies, food security and rural livelihoods, and > 85% of livestock keepers live in extreme poverty. With poverty elimination central to the Sustainable Development Goals, livestock keepers are therefore critically important. Foot-and-mouth disease is a highly contagious livestock disease widespread in Africa that contributes to this poverty. Despite its US$2.3 billion impact, control of the disease is not prioritized: standard vaccination regimens are too costly, its impact on the poorest is underestimated, and its epidemiology is too weakly understood. Our integrated analysis in Tanzania shows that the disease is of high concern, reduces household budgets for human health, and has major impacts on milk production and draft power for crop production. Critically, foot-and-mouth disease outbreaks in cattle are driven by livestock-related factors with a pattern of changing serotype dominance over time. Contrary to findings in southern Africa, we find no evidence of frequent infection from wildlife, with outbreaks in cattle sweeping slowly across the region through a sequence of dominant serotypes. This regularity suggests that timely identification of the epidemic serotype could allow proactive vaccination ahead of the wave of infection, mitigating impacts, and our preliminary matching work has identified potential vaccine candidates. This strategy is more realistic than wildlife-livestock separation or conventional foot-and-mouth disease vaccination approaches. Overall, we provide strong evidence for the feasibility of coordinated foot-and-mouth disease control as part of livestock development policies in eastern Africa, and our integrated socioeconomic, epidemiological, laboratory and modelling approach provides a framework for the study of other disease systems.

Brucellosis Risk in Urban and Agro-pastoral Areas in Tanzania

Epidemiology of human and animal brucellosis may depend on ecological conditions. A cross-sectional study was conducted to compare prevalence and risk factors of bovine brucellosis, and risky behaviours for the human infection between urban and agro-pastoral areas in Morogoro region, Tanzania. Cattle blood sampling and interviews using a structured questionnaire were conducted with farmers. Rose-Bengal test was conducted for the cattle sera, and positive samples were confirmed with competitive ELISA. Farm-level sero-prevalences were 0.9% (1/106, 95% CI 0.0-5.9%) and 52.9% (9/17, 95% CI 28.5-76.1%) in urban and agro-pastoral areas, respectively. The animal-level-adjusted prevalences were 0.2% (1/667, 95% CI 0.0-1.1%) and 7.0% (28/673, 95% CI 5.7-8.4%) in those areas. The final farm-level model including both areas found two risk factors: history of abortion in the herd (P < 0.01) and cattle grazing (P = 0.07). The animal-level risk factors in agro-pastoral areas were age (P = 0.04) and history of abortion (P = 0.03). No agro-pastoral farmer knew about Brucella vaccine. Agro-pastoralists generally had poorer knowledge on brucellosis and practiced significantly more risky behaviours for human brucellosis such as drinking raw milk (17.6%, P < 0.01) and blood (35.3%, P < 0.01), and helping cattle birth (100%, P = 0.04) than urban farmers (0, 0 and 79.2%, respectively). Intervention programs through education including both human and animal health particularly targeting agro-pastoralists would be needed.

Assessment of GeneXpert GxAlert platform for multi-drug resistant tuberculosis diagnosis and patients' linkage to care in Tanzania

Objective

The gap between patients diagnosed with multi-drug resistant tuberculosis (MDR-TB) and enrolment in treatment is one of the major challenges in tuberculosis control programmes. A 4-year (2013–2016) retrospective review of patients’ clinical data and subsequent in-depth interviews with health providers were conducted to assess the effectiveness of the GeneXpert GxAlert platform for MDR-TB diagnosis and its impact on linkage of patients to care in Tanzania.

Results

A total of 782 new rifampicin resistant cases were notified, but only 242 (32.3%) were placed in an MDR-TB regimens. The remaining 540 (67.07%) patients were not on treatment, of which 103 patients had complete records on the GxAlert database. Of the 103 patients: 39 were judged as untraceable; 27 died before treatment; 12 were treated with first-line anti-TBs; 9 repeat tests did not show rifampicin resistance; 15 were not on treatment due to communication breakdown, and 1 patient was transferred outside the country. In-depth interviews with health providers suggested that the pre-treatment loss for the MDR-TB patients was primarily attributed to health system and patients themselves. We recommend strengthening the health system by developing and implementing well-defined interventions to ensure all diagnosed MDR-TB patients are accurately reported and timely linked to treatment.

Self-Reported Symptoms and Pesticide Use among Farm Workers in Arusha, Northern Tanzania: A Cross Sectional Study

The objective of the study was to describe self-reported health symptoms, the use of personal protective gear and clothing and poor safety procedures when applying pesticides among farm workers. A total of 128 adult farm workers were interviewed using a structured questionnaire during the farming season. The commonly used pesticides included profenofos, mancozeb, chlorpyrifos, cypermethrin, deltamethrin, permethrin, lambda-cyhalothrin, endosulfan and carbosulfan. The majority (>90%) of farm workers used no personal protective clothing while handling pesticides. More than one-third of farm workers ate and drank without washing their hands following pesticide handling, while a smaller number smoked or chewed gum. Wearing special boots during pesticide application was found to reduce the risk of skin rash (OR = 0.2, 95% CI: 0.06-0.66), whereas smoking when applying pesticides increased the risk of chest pain occurrence (OR = 4.0, 95% CI: 1.14-15.43), as well as forgetfulness (OR = 4.0, 95% CI: 1.30-14.02). Chewing gum and eating when applying pesticides was associated with diarrhoea (OR = 11.0, 95% CI: 1.80-6.84 and OR = 7.0, 95% CI: 1.27-3.67 respectively). The increased self-reported prevalence of post-exposure adverse health effects among farm workers was associated with poor use of personal protective clothing and poor safety practices during pesticide use and handling. These data indicate the need for improved availability and use of protective equipment, and training in crop and pest management practices to prevent risky behavioursand for safer and sustainable vegetable production.

Assessment of sputum smear-positive but culture-negative results among newly diagnosed pulmonary tuberculosis patients in Tanzania

Diagnosis of pulmonary tuberculosis (TB) in technology-limited countries is widely achieved by smear microscopy, which has limited sensitivity and specificity. The frequency and clinical implication of smear-positive but culture-negative among presumptive TB patients remains unclear. A cross-sectional substudy was conducted which aimed to identify the proportion of nontuberculous mycobacteria (NTM) infections among 94 “smear-positive culture-negative” patients diagnosed between January 2013 and June 2016 in selected health facilities in Tanzania. Out of 94 sputa, 25 (26.60%) were GeneXpert® mycobacteria TB positive and 11/94 (11.70%) repeat-culture positive; 5 were Capilia TB-Neo positive and confirmed by GenoType MTBC to be Mycobacterium tuberculosis/Mycobacterium canettii. The remaining 6 Capilia TB-Neo negative samples were genotyped by GenoType® CM/AS, identifying 3 (3.19%) NTM, 2 Gram positive bacteria, and 1 isolate testing negative, together, making a total of 6/94 (6.38%) confirmed false smear-positives. Twenty-eight (29.79%) were confirmed TB cases, while 60 (63.83%) remained unconfirmed cases. Out of 6 (6.38%) patients who were HIV positive, 2 patients were possibly coinfected with mycobacteria. The isolation of NTM and other bacteria among smear-positive culture-negative samples and the presence of over two third of unconfirmed TB cases emphasize the need of both advanced differential TB diagnostic techniques and good clinical laboratory practices to avoid unnecessary administration of anti-TB drugs.

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.

Toward Elimination of Dog-Mediated Human Rabies: Experiences from Implementing a Large-scale Demonstration Project in Southern Tanzania

A Rabies Elimination Demonstration Project was implemented in Tanzania from 2010 through to 2015, bringing together government ministries from the health and veterinary sectors, the World Health Organization, and national and international research institutions. Detailed data on mass dog vaccination campaigns, bite exposures, use of post-exposure prophylaxis (PEP), and human rabies deaths were collected throughout the project duration and project areas. Despite no previous experience in dog vaccination within the project areas, district veterinary officers were able to implement district-wide vaccination campaigns that, for most part, progressively increased the numbers of dogs vaccinated with each phase of the project. Bite exposures declined, particularly in the southernmost districts with the smallest dog populations, and health workers successfully transitioned from primarily intramuscular administration of PEP to intradermal administration, resulting in major cost savings. However, even with improved PEP provision, vaccine shortages still occurred in some districts. In laboratory diagnosis, there were several logistical challenges in sample handling and submission but compared to the situation before the project started, there was a moderate increase in the number of laboratory samples submitted and tested for rabies in the project areas with a decrease in the proportion of rabies-positive samples over time. The project had a major impact on public health policy and practice with the formation of a One Health Coordination Unit at the Prime Minister's Office and development of the Tanzania National Rabies Control Strategy, which lays a roadmap for elimination of rabies in Tanzania by 2030 by following the Stepwise Approach towards Rabies Elimination (SARE). Overall, the project generated many important lessons relevant to rabies prevention and control in particular and disease surveillance in general. Lessons include the need for (1) a specific unit in the government for managing disease surveillance; (2) application of innovative data collection and management approaches such as the use of mobile phones; (3) close cooperation and effective communication among all key sectors and stakeholders; and (4) flexible and adaptive programs that can incorporate new information to improve their delivery, and overcome challenges of logistics and procurement.

The efficacy of alcelaphine herpesvirus-1 (AlHV-1) immunization with the adjuvants Emulsigen® and the monomeric TLR5 ligand FliC in zebu cattle against AlHV-1 malignant catarrhal fever induced by experimental virus challenge

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Vaccination induces a pharyngeal antibody response in shorthorn zebu cross (SZC).

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Direct challenge with the AlHV-1 virus is effective at inducing MCF in SZC.

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Attenuated AlHV–1 + Emulsigen^® vaccine efficacy in SZC calculated to be 50%.

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Bacterial flagellin is not a good adjuvant as inclusion reduced antibody response.

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We provide evidence that non-fatal AlHV-1 infections occur in SZC.

Malignant catarrhal fever (MCF) is a fatal disease of cattle that, in East Africa, follows contact with wildebeest excreting alcelaphine herpesvirus 1 (AlHV-1). Recently an attenuated vaccine (atAlHV-1) was tested under experimental challenge on Friesian-Holstein (FH) cattle and gave a vaccine efficacy (VE) of approximately 90%. However testing under field conditions on an East African breed, the shorthorn zebu cross (SZC), gave a VE of 56% suggesting that FH and SZC cattle may respond differently to the vaccine. To investigate, a challenge trial was carried out using SZC. Additionally three adjuvant combinations were tested: (i) Emulsigen^®, (ii) bacterial flagellin (FliC) and (iii) Emulsigen^® + bacterial flagellin. We report 100% seroconversion in all immunized cattle. The group inoculated with atAlHV-1 + Emulsigen^® had significantly higher antibody titres than groups inoculated with FliC, the smallest number of animals that became infected and the fewest fatalities, suggesting this was the most effective combination. A larger study is required to more accurately determine the protective effect of this regime in SZC. There was an apparent inhibition of the antibody response in cattle inoculated with atAlHV-1 + FliC, suggesting FliC might induce an immune suppressive mechanism. The VE in SZC (50–60%) was less than that in FH (80–90%). We speculate that this might be due to increased risk of disease in vaccinated SZC (suggesting that the vaccine may be less effective at stimulating an appropriate immune response in this breed) and/or increased survival in unvaccinated SZC (suggesting that these cattle may have a degree of prior immunity against infection with AlHV-1).

Mobile Phones As Surveillance Tools: Implementing and Evaluating a Large-Scale Intersectoral Surveillance System for Rabies in Tanzania

Katie Hampson and colleagues describe their experience of developing and deploying a large-scale rabies surveillance system based on mobile phones in southern Tanzania.

Genetic profile of Mycobacterium tuberculosis and treatment outcomes in human pulmonary tuberculosis in Tanzania

Information on the different spoligotype families of Mycobacterium tuberculosis in Tanzania is limited, and where available, restricted to small geographical areas. This article describes the genetic profile of M tuberculosis across Tanzania and suggests how spoligotype families might affect drug resistance and treatment outcomes for smear positive pulmonary tuberculosis patients in Tanzania. We conducted the study from 2006 to 2008, and the isolates were obtained from samples collected under the routine drug resistance surveillance system. The isolates were from specimens collected from 2001 to 2007, and stored at the Central and Reference Tuberculosis Laboratory. A total of 487 isolates from 23 regions in the country were spoligotyped. We were able to retrieve clinical information for 446 isolates only. Out of the 487 isolates spoligotyped, 195(40.0%) belonged to the Central Asian (CAS) family, 84 (17.5%) to the Latin American Mediterranean (LAM) family, 49 (10.1%) to the East-African Indian (EAI) family, and 33 (6.8%) to the Beijing family. Other isolates included 1 (0.2%) for H37Rv, 10 (2.1%) for Haarlem, 4 (0.8%) for S family, 58 (11.9%) for T family and 52 (10.7%) for unclassified. No spoligotype patterns were consistent with M bovis. Regarding treatment outcomes, the cure rate was 80% with no significant variation among the spoligotype families. The overall level of MDR TB was 2.5% (3/12 1), with no significant difference among the spoligotype families. All Beijing strains (11.8%, 30/254) originated from the Eastern and Southern zones of the country, of which 80% were from Dar es Salaam. Isolates from the CAS and T families were reported disproportionately from the Eastern-Southern zone, and EAI and LAM families from the Northern-Lake zones but the difference was not statistically significant. Five isolates were identified as non-tuberculous Mycobacteria. In conclusion, M. tuberculosis isolates from pulmonary tuberculosis cases in Tanzania were classified mostly within the CAS, LAM, and EAI and T families, while the Beijing family comprised about 7% isolates only. Consistently good treatment outcomes were recorded across these spoligotype families. The proportion of drug resistance strains was low. The findings also suggest variation of spoligotype families with varying geographical localities within the country, and identify this area for further research to confirm this finding.

A field vaccine trial in Tanzania demonstrates partial protection against malignant catarrhal fever in cattle

Malignant catarrhal fever (MCF) is a fatal lymphoproliferative disease of cattle that, in East Africa, results from transmission of the causative virus, alcelaphine herpesvirus 1 (AlHV-1), from wildebeest. A vaccine field trial involving an attenuated AlHV-1 virus vaccine was performed over two wildebeest calving seasons on the Simanjiro Plain of northern Tanzania. Each of the two phases of the field trial consisted of groups of 50 vaccinated and unvaccinated cattle, which were subsequently exposed to AlHV-1 challenge by herding toward wildebeest. Vaccination resulted in the induction of virus-specific and virus-neutralizing antibodies. Some cattle in the unvaccinated groups also developed virus-specific antibody responses but only after the start of the challenge phase of the trial. PCR of DNA from blood samples detected AlHV-1 infection in both groups of cattle but the frequency of infection was significantly lower in the vaccinated groups. Some infected animals showed clinical signs suggestive of MCF but few animals went on to develop fatal MCF, with similar numbers in vaccinated and unvaccinated groups. This study demonstrated a baseline level of MCF-seropositivity among cattle in northern Tanzania of 1% and showed that AlHV-1 virus-neutralizing antibodies could be induced in Tanzanian zebu shorthorn cross cattle by our attenuated vaccine, a correlate of protection in previous experimental trials. The vaccine reduced infection rates by 56% in cattle exposed to wildebeest but protection from fatal MCF could not be determined due to the low number of fatal cases.

APOPO's tuberculosis research agenda: achievements, challenges and prospects

This article describes Anti-Persoonsmijnen Ontmijnende Product Ontwikkeling (APOPO) recent use of specially trained African giant pouched rats as detectors of pulmonary tuberculosis in people living in Tanzania. It summarizes the achievements and challenges encountered over the years and outlines future prospects. Since 2008, second-line screening by the rats has identified more than 2000 tuberculosis-positive patients who were missed by microscopy at Direct Observation of Treatment--Short Course centres in Tanzania. Moreover, data that are reviewed herein have been collected with respect to the rats' sensitivity and specificity in detecting tuberculosis. Findings strongly suggest that scent-detecting rats offer a quick and practical tool for detecting pulmonary tuberculosis and within the year APOPO's tuberculosis-detection project will be extended to Mozambique. As part of its local capacity building effort, APOPO hires and trains Tanzanians to play many important roles in its TB detection project and provides research and training opportunities for Tanzanian students.

One Health: a concept led by Africa, with global benefits

Titus Mlengeya Kamani and others argue that Africa is well positioned and equipped to conduct and benefit from an integrated approach

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.

Alcelaphine Herpesvirus-1 (Malignant Catarrhal Fever Virus) in Wildebeest Placenta: Genetic Variation of ORF50 and A9.5 Alleles

Alcelaphine herpesvirus–1 (AlHV-1), a causative agent of malignant catarrhal fever in cattle, was detected in wildebeest (Connochaetes taurinus) placenta tissue for the first time. Although viral load was low, the finding of viral DNA in over 50% of 94 samples tested lends support to the possibility that placental tissue could play a role in disease transmission and that wildebeest calves are infected in utero. Two viral loci were sequenced to examine variation among virus samples obtained from wildebeest and cattle: the ORF50 gene, encoding the lytic cycle transactivator protein, and the A9.5 gene, encoding a novel polymorphic viral glycoprotein. ORF50 was well conserved with six newly discovered alleles differing at only one or two base positions. In contrast, while only three new A9.5 alleles were discovered, these differed by up to 13% at the nucleotide level and up to 20% at the amino acid level. Structural homology searching performed with the additional A9.5 sequences determined in this study adds power to recent analysis identifying the four-helix bundle cytokine interleukin-4 (IL4) as the major homologue. The majority of MCF virus samples obtained from Tanzanian cattle and wildebeest encoded A9.5 polypeptides identical to the previously characterized A9.5 allele present in the laboratory maintained AlHV-1 C500 strain. This supports the view that AlHV-1 C500 is suitable for the development of a vaccine for wildebeest-associated MCF.

The economic impact of malignant catarrhal fever on pastoralist livelihoods

This study is the first to partially quantify the potential economic benefits that a vaccine, effective at protecting cattle against malignant catarrhal fever (MCF), could accrue to pastoralists living in East Africa. The benefits would result from the removal of household resource and management costs that are traditionally incurred avoiding the disease. MCF, a fatal disease of cattle caused by a virus transmitted from wildebeest calves, has plagued Maasai communities in East Africa for generations. The threat of the disease forces the Maasai to move cattle to less productive grazing areas to avoid wildebeest during calving season when forage quality is critical. To assess the management and resource costs associated with moving, we used household survey data. To estimate the costs associated with changes in livestock body condition that result from being herded away from wildebeest calving grounds, we exploited an ongoing MCF vaccine field trial and we used a hedonic price regression, a statistical model that allows estimation of the marginal contribution of a good's attributes to its market price. We found that 90 percent of households move, on average, 82 percent of all cattle away from home to avoid MCF. In doing so, a herd's productive contributions to the household was reduced, with 64 percent of milk being unavailable for sale or consumption by the family members remaining at the boma (the children, women, and the elderly). In contrast cattle that remained on the wildebeest calving grounds during the calving season (and survived MCF) remained fully productive to the family and gained body condition compared to cattle that moved away. This gain was, however, short-lived. We estimated the market value of these condition gains and losses using hedonic regression. The value of a vaccine for MCF is the removal of the costs incurred in avoiding the disease.

Spatial predictors of bovine tuberculosis infection and Brucella spp. exposure in pastoralist and agropastoralist livestock herds in the Ruaha ecosystem of Tanzania

While many studies investigate animal-related risk factors for disease, few have considered environmental or spatial risk factors in the dynamics of bovine tuberculosis (bTB) and brucellosis. In the Ruaha ecosystem of Tanzania, we investigated the role of household location as a predictor for infection with Mycobacterium bovis and exposure to Brucella in pastoralist and agropastoralist cattle herds in a typical African wildlife-livestock-human interface. ArcGIS was utilized to calculate Euclidian distances between households and the nearest river, village center, protected area, and other infected households, followed by multivariate logistic regression to assess the association between risk factors and herd-level bTB and Brucella outcomes. Global and local spatial clustering of bTB-infected and Brucella-exposed herds was explored using the Cuzick-Edward’s test and SaTScan spatial scan statistics. Households located farther from rivers and closer to village centers and herds belonging to agropastoralists were more likely to have bTB-positive cattle. Risk of Brucella exposure increased with proximity to protected areas. One spatial cluster of households with Brucella spp. seropositive cattle was identified. Spatial factors may be useful for assessing disease risk and for formulating intervention and control strategies for households that manage cattle in ecosystems characterized by seasonally limited resources and intense wildlife-livestock interfaces.

The global one health paradigm: challenges and opportunities for tackling infectious diseases at the human, animal, and environment interface in low-resource settings

Zoonotic infectious diseases have been an important concern to humankind for more than 10,000 years. Today, approximately 75% of newly emerging infectious diseases (EIDs) are zoonoses that result from various anthropogenic, genetic, ecologic, socioeconomic, and climatic factors. These interrelated driving forces make it difficult to predict and to prevent zoonotic EIDs. Although significant improvements in environmental and medical surveillance, clinical diagnostic methods, and medical practices have been achieved in the recent years, zoonotic EIDs remain a major global concern, and such threats are expanding, especially in less developed regions. The current Ebola epidemic in West Africa is an extreme stark reminder of the role animal reservoirs play in public health and reinforces the urgent need for globally operationalizing a One Health approach. The complex nature of zoonotic diseases and the limited resources in developing countries are a reminder that the need for implementation of Global One Health in low-resource settings is crucial. The Veterinary Public Health and Biotechnology (VPH-Biotec) Global Consortium launched the International Congress on Pathogens at the Human-Animal Interface (ICOPHAI) in order to address important challenges and needs for capacity building. The inaugural ICOPHAI (Addis Ababa, Ethiopia, 2011) and the second congress (Porto de Galinhas, Brazil, 2013) were unique opportunities to share and discuss issues related to zoonotic infectious diseases worldwide. In addition to strong scientific reports in eight thematic areas that necessitate One Health implementation, the congress identified four key capacity-building needs: (1) development of adequate science-based risk management policies, (2) skilled-personnel capacity building, (3) accredited veterinary and public health diagnostic laboratories with a shared database, and (4) improved use of existing natural resources and implementation. The aim of this review is to highlight advances in key zoonotic disease areas and the One Health capacity needs.

Mycobacterium genotypes in pulmonary tuberculosis infections and their detection by trained African giant pouched rats

Tuberculosis (TB) diagnosis in low-income countries is mainly done by microscopy. Hence, little is known about the diversity of Mycobacterium spp. in TB infections. Different genotypes or lineages of Mycobacterium tuberculosis vary in virulence and induce different inflammatory and immune responses. Trained Cricetomys rats show a potential for rapid diagnosis of TB. They detect over 28 % of smear-negative, culture-positive TB. However, it is unknown whether these rats can equally detect sputa from patients infected with different genotypes of M. tuberculosis. A 4-month prospective study on diversity of Mycobacterium spp. was conducted in Dar es Salaam, Tanzania. 252 sputa from 161 subjects were cultured on Lowenstein-Jensen medium and thereafter tested by rats. Mycobacterial isolates were subjected to molecular identification and multispacer sequence typing (MST) to determine species and genotypes. A total of 34 Mycobacterium spp. isolates consisting of 32 M. tuberculosis, 1 M. avium subsp. hominissuis and 1 M. intracellulare were obtained. MST analyses of 26 M. tuberculosis isolates yielded 10 distinct MST genotypes, including 3 new genotypes with two clusters of related patterns not grouped by geographic areas. Genotype MST-67, shared by one-third of M. tuberculosis isolates, was associated with the Mwananyamala clinic. This study shows that diverse M. tuberculosis genotypes (n = 10) occur in Dar es Salaam and trained rats detect 80 % of the genotypes. Sputa with two M. tuberculosis genotypes (20 %), M. avium hominissuis and M. intracellulare were not detected. Therefore, rats detect sputa with different M. tuberculosis genotypes and can be used to detect TB in resource-poor countries.

African 2, a clonal complex of Mycobacterium bovis epidemiologically important in East Africa

We have identified a clonal complex of Mycobacterium bovis isolated at high frequency from cattle in Uganda, Burundi, Tanzania, and Ethiopia. We have named this related group of M. bovis strains the African 2 (Af2) clonal complex of M. bovis. Af2 strains are defined by a specific chromosomal deletion (RDAf2) and can be identified by the absence of spacers 3 to 7 in their spoligotype patterns. Deletion analysis of M. bovis isolates from Algeria, Mali, Chad, Nigeria, Cameroon, South Africa, and Mozambique did not identify any strains of the Af2 clonal complex, suggesting that this clonal complex of M. bovis is localized in East Africa. The specific spoligotype pattern of the Af2 clonal complex was rarely identified among isolates from outside Africa, and the few isolates that were found and tested were intact at the RDAf2 locus. We conclude that the Af2 clonal complex is localized to cattle in East Africa. We found that strains of the Af2 clonal complex of M. bovis have, in general, four or more copies of the insertion sequence IS6110, in contrast to the majority of M. bovis strains isolated from cattle, which are thought to carry only one or a few copies.

Quantifying risk factors for human brucellosis in rural northern Tanzania

BACKGROUND

Brucellosis is a zoonosis of veterinary, public health and economic significance in most developing countries. Human brucellosis is a severely debilitating disease that requires prolonged treatment with a combination of antibiotics. The disease can result in permanent and disabling sequel, and results in considerable medical expenses in addition to loss of income due to loss of working hours. A study was conducted in Northern Tanzania to determine the risk factors for transmission of brucellosis to humans in Tanzania.

METHODS

This was a matched case-control study. Any patient with a positive result by a competitive ELISA (c-ELISA) test for brucellosis, and presenting to selected hospitals with at least two clinical features suggestive of brucellosis such as headache, recurrent or continuous fever, sweating, joint pain, joint swelling, general body malaise or backache, was defined as a case. For every case in a district, a corresponding control was traced and matched by sex using multistage cluster sampling. Other criteria for inclusion as a control included a negative c-ELISA test result and that the matched individual would present to hospital if falls sick.

RESULTS

Multivariable analysis showed that brucellosis was associated with assisted parturition during abortion in cattle, sheep or goat. It was shown that individuals living in close proximity to other households had a higher risk of brucellosis. People who were of Christian religion were found to have a higher risk of brucellosis compared to other religions. The study concludes that assisting an aborting animal, proximity to neighborhoods, and Christianity were associated with brucellosis infection. There was no association between human brucellosis and Human Immunodeficiency Virus (HIV) serostatus. Protecting humans against contact with fluids and tissues during assisted parturition of livestock may be an important means of reducing the risk of transferring brucellosis from livestock to humans. These can be achieved through health education to the communities where brucellosis is common.

Zoonotic tuberculosis and brucellosis in Africa: neglected zoonoses or minor public-health issues? The outcomes of a multi-disciplinary workshop

Late in 2007, veterinary, medical and anthropological professionals from Europe and Africa met in a 2-day workshop in Pretoria, South Africa, to evaluate the burden, surveillance and control of zoonotic tuberculosis and brucellosis in sub-Saharan Africa. Keynote presentations reviewed the burden of these diseases on human and livestock health, the existing diagnostic tools, and the available control methods. These presentations were followed by group discussions and the formulation of recommendations. The presence of Mycobacterium bovis and Brucella spp. in livestock was considered to be a serious threat to public health, since livestock and animal products are the only source of such infections in human beings. The impact of these pathogens on human health appears to be relatively marginal, however, when compared with Mycobacterium tuberculosis infections and drug resistance, HIV and malaria. Appropriate diagnostic tools are needed to improve the detection of M. bovis and Brucella spp. in humans. In livestock, the 'test-and-slaughter' approach and the pasteurization of milk, which have been used successfully in industrialized countries, might not be the optimal control tools in Africa. Control strategies should fit the needs and perceptions of local communities. Improved intersectoral and international collaboration in surveillance, diagnosis and control, and in the education of medical and veterinary personnel, are advocated.

African pouched rats for the detection of pulmonary tuberculosis in sputum samples

SETTING

Resource-limited settings in sub-Saharan African countries.

OBJECTIVE

To utilise African giant pouched rats (Cricetomys gambianus) for the diagnosis of tuberculosis (TB) in human sputum.

DESIGN

A specially designed cage with 10 sniffing holes and cassette-carrier was used. The sputum samples were put in the sample cassette, containing 10 samples in line, placed under matching sniffing holes. Rats were trained to sniff each consecutive sample, and indicate TB positives by fixing their nose for 5 seconds at the sniffing hole. This behaviour was maintained by food reinforcement upon correct indications. A total of 3416 samples were used.

RESULTS

Of the 20 trained rats, 18 were able to discriminate positive from negative sputum samples, with average daily sensitivities ranging from 72% to 100%, and average daily false-positives ranging from 0.7% to 8.1%. The use of multiple rats significantly increased sensitivity and negative predictive value.

CONCLUSION

Utilising trained sniffer rats for TB detection is a potentially faster screening method and is at least as sensitive as smear microscopy. This method could therefore be suitable for active case finding, especially where large numbers of samples are to be analysed in resource-limited settings, to complement existing diagnostic techniques.

Characterisation of mycobacteria isolated from slaughter cattle in pastoral regions of Uganda

Background

Bovine tuberculosis is a zoonotic problem in pastoral cattle and communities in Uganda. Tuberculin tests in pastoral cattle had shown a high herd but low animal prevalence, with a high proportion of avian reactors. No work had been done to identify the mycobacterial species involved. The objective of the study was to isolate and characterise Mycobacterial species causing tuberculous lesions in slaughtered animals. Lesioned organs compatible with bovine tuberculosis in slaughtered cattle from pastoral areas in Uganda were collected and cultured to isolate mycobacteria. AccuProbe culture identification kits for the Mycobacterium tuberculosis complex, M. avium complex and M. avium were used to identify the isolates. Spoligotyping and Insertion Sequence (IS) 1311 and IS1245 Restriction Fragment Length Polymorphism analysis (RFLP) were used to further characterise the isolates.

Results

Of the 61 lesioned organs and tissues cultured, 19 isolates were identified as M. bovis, 3 as M. avium subsp.hominissuis, 1 as M. intracellulare, 1 as a mixed culture of M. bovis and M. avium sp. and 1 as M. avium sp. and unidentified mycobacteria. Eleven other mycobacteria outside the tuberculosis and avium complex groups were also isolated. Ten new spoligopatterns grouped into three clusters were identified from M. bovis isolates. Two of the three M. avium subsp.hominissuis isolates showed similar patterns on the IS1311 RFLP but all were different on the IS1245 RFLP.

Conclusion

The isolation of M. bovis confirms the ongoing infection with spoligotypes unique to Uganda. Isolation of environmental mycobacteria could explain the high avian or non specific tuberculin reactor patterns commonly observed in pastoral cattle and suggests their pathogenic or opportunistic role in the infection of cattle with disseminated bovine tuberculous lesions.