Background:Emerging zoonotic diseases account for 75% of new infectious threats worldwide due to increasing human-animal-environment interactions, land-use change, wildlife trade, and climate variability. The COVID-19 pandemic underscored the need for integrated, joint approaches such as One Health to strengthen prevention, early detection, and response to zoonotic risks. The study objective is to synthesize evidence on the burden, drivers, challenges, and One Health strategies for combating emerging zoonotic diseases, and to identify actions to improve implementation at local, national, regional, and global levels. Methodology:A systematic literature search was conducted across PubMed, EMBASE, Scopus, and Google Scholar. Studies were included if they examined zoonotic diseases using a One Health approach and were published in English. Data were synthesized thematically to identify key patterns, intervention strategies, and gaps. Results:Zoonotic diseases impose morbidity, mortality, and economic losses. Evidence shows that One Health interventions such as integrated surveillance, joint outbreak investigations, and targeted vaccination have improved detection and control of diseases. However, implementation remains hindered by fragmented communication across sectors, policy inconsistencies, limited laboratory and surveillance capacity, inadequate cross-border cooperation, and limited funding. Vulnerabilities are particularly pronounced in low- and middle-income countries. Conclusion:Effective implementation needs improved governance, sustainable financing, aligned policies, robust surveillance and laboratory systems, and meaningful community engagement. Investing in interdisciplinary research, early warning systems, and integrated response mechanisms will enhance preparedness and reduce zoonotic disease transmission. A well-resourced One Health framework is essential to protect human, animal, and environmental health.
Background In Tanzania, ceftriaxone is one of the most commonly prescribed antibiotics. However, there is quite a significant variation in cost for numerous ceftriaxone brands, leading to the perception that pricier options are more effective. Yet, limited empirical data support this perception.Methods Five ceftriaxone brands with a wide price range were tested in vitro against a ceftriaxone-sensitive Escherichia coli clinical isolate using microdilution and spectrophotometry. Brands were evaluated across a spectrum of concentrations. Bacterial growth inhibition was measured using optical density. Analysis of variance was used to compare the bacterial optical densities among the brands.Results All brands were comparable at all tested concentrations, with peak inhibition above 1.95 mg/L.Conclusions Despite significant price disparities, low-cost and high-cost ceftriaxone brands demonstrated similar in vitro performance against E. coli. This challenges the notion that higher-priced options offer better performance. Further, in vivo studies are recommended to validate these findings.
Background:Antimicrobial consumption continues to rise globally and contributes to the emergence and spread of antimicrobial resistance. This study aimed to evaluate antimicrobial prescribing patterns in a selected tertiary hospital in Tanzania. Methods:This cross-sectional study was conducted for one year (September 2021-September 2022) at Mbeya Zonal Referral Hospital, a public hospital in the southern highlands zone of Tanzania. Data on clinical diagnosis, laboratory tests, prescribed antimicrobials, and prescribers' designations were collected through a custom eMedical system, aligning antimicrobials with the WHO's 2021 AWaRe classification. Descriptive analysis was performed to assess the pattern of antimicrobial prescriptions. Results:Of 2,293 antimicrobial prescriptions, 62.41% were ACCESS, 37.42% were WATCH, and 0.17% fell in the RESERVE categories. Metronidazole, accounting for 23.8%, was the most commonly prescribed antimicrobial. More than 50% of the ACCESS and WATCH prescriptions were justified by laboratory diagnosis and were predominantly prescribed by clinicians. A very small proportion of prescriptions (<1%) were informed by culture and sensitivity (C/S) testing. The Paediatric department had the majority of WATCH prescriptions (72.2%). Conclusion:The prescribing patterns at the study hospital generally align with WHO AWaRe guidelines, potentially mitigating antimicrobial resistance. Nevertheless, the scarcity of culture and sensitivity testing is a concern that warrants targeted improvement.
Background: In 2017, Mbeya Zonal Referral Hospital (MZRH) and the University of South Carolina (UofSC) agreed to collaboratively strengthen antimicrobial prescribing in the southern highlands of Tanzania and train a new generation of clinicians in responsible antimicrobial use. Methods: Key stakeholders and participants were identified and the Mbeya Antimicrobial Stewardship Team (MAST) was created. The team identified assets brought by the collaborators, and four investigations of baseline needs were developed. These investigations included (a) a baseline clinician survey regarding antimicrobial resistance and stewardship, (b) a serial chart review of inpatient antimicrobial prescribing practices, (c) an investigation of antimicrobial resistance rates using existing isolates at the MZRH laboratory, and (d) a survey of antimicrobial availability at community pharmacies in the city. Results: 91% of physicians believe antimicrobial resistance is problem in Tanzania, although only 29% of physicians were familiar with the term "antimicrobial stewardship". Escherichia coli isolates had resistance rates of over 60% to the commonly used agents ciprofloxacin, trimethoprim-sulfamethoxazole, and ceftriaxone. Thirteen out of 14 community pharmacies offered over-the-counter antibiotics for upper respiratory symptoms. Conclusions: International antimicrobial stewardship collaborations can successfully identify opportunities and needs. Evaluating the team's efforts to improve patient outcomes will be essential.
BackgroundSusceptibility to HIV has been linked to systemic CD4+ T cell activation in cohorts of seronegative individuals with high HIV-exposure risk. We recently described an increased risk of HIV transmission in individuals infected with Wuchereria bancrofti, the causative agent for lymphatic filariasis, in a prospective cohort study. However, the reason for this phenomenon needs further investigation.Methodology/principal findingsTwo-hundred and thirty-five HIV negative adults were tested using Trop Bio ELISA for detection of W. bancrofti infection and Kato Katz urine filtration and stool based RT-PCR for detection of soil transmitted helminths and schistosomiasis. FACS analysis of the fresh peripheral whole blood was used to measure T cell activation markers (HLA-DR, CD38), differentiation markers (CD45, CD27), markers for regulatory T cells (FoxP3, CD25) and the HIV entry receptor CCR5. Frequencies of activated HLA-DRpos CD4 T cells were significantly increased in subjects with W. bancrofti infection (n = 33 median: 10.71%) compared to subjects without any helminth infection (n = 42, median 6.97%, p = 0.011) or those with other helminths (Schistosoma haematobium, S. mansoni, Trichuris trichiura, Ascaris lumbricoides, hookworm) (n = 151, median 7.38%, p = 0.009). Similarly, a significant increase in HLA-DRposCD38pos CD4 T cells and effector memory cells CD4 T cells (CD45ROposCD27neg) was observed in filarial infected participants. Multivariable analyses further confirmed a link between W. bancrofti infection and systemic activation of CD4 T cells independent of age, fever, gender or other helminth infections.Conclusions/significanceW. bancrofti infection is linked to systemic CD4 T cell activation, which may contribute to the increased susceptibility of W. bancrofti infected individuals to HIV infection.
Antimicrobial resistance is a growing concern in sub-Saharan Africa, and antimicrobial stewardship (AMS) programs have not been widely implemented in this region. We evaluated antibiotic prescribing patterns and concordance with national guidelines at Mbeya Zonal Referral Hospital (MZRH) in Tanzania. Adult inpatient medical records were chronologically reviewed from January 1, 2018 until 100 records documenting antibiotic therapy were evaluated. The primary endpoint was concordance with national guidelines for indication-based antibiotic selection and duration. Data were summarized using descriptive statistics. Overall, 155 records with sufficient data were reviewed. The 100 records which involved antibiotic therapy represented 171 unique antibiotic courses. The most common indication for antibiotics was bacterial pneumonia. Ceftriaxone and metronidazole, the most commonly used antibiotics, were administered in 40% and 24% of courses, respectively. Indication-based antibiotic selection was concordant with national guidelines in 63% of courses, but this fell to 15% when course duration was taken into account. Antibiotic courses were completed as prescribed 28% of the time among evaluable courses. A microbiologic culture of any kind was obtained in 17% of patients. In conclusion, antibiotic therapy was often incomplete, was generally guideline discordant, exhibited limited diversity of selection, and frequently lacked diagnostic confirmation. These data, combined with local susceptibility patterns, may be used to foster AMS efforts for improved compliance with guidelines at MZRH in the future.
A conference called "Outbreaks in Tanzania-Are We Prepared?" was held in Mbeya, Tanzania, on September 14 and 15, 2015, accompanied by a training workshop on infection prevention and control for local stakeholders from September 16 to 18, 2015. The objective of the conference was to revisit past disease epidemics and to reflect on the current status of surveillance and outbreak preparedness in Tanzania, including an overview of agents relevant to biosecurity. The conference brought together national authorities of Tanzania, regional public health representatives, people from research and academic institutions, and international stakeholders. Key findings of the event were: (1) although national frameworks for surveillance and preparedness exist, their implementation presents challenges, and local health structures need support in implementation; (2) the ability to identify and properly manage infectious diseases of public health concern is crucial in empowering the local health workforce to contribute to surveillance measures, which in turn allows for realistic risk assessments and management algorithms; and (3) in settings of limited resources, research activities acquire an additional responsibility toward national surveillance and capacity building and should be integrated into national epidemic preparedness plans. This event was the first of its kind in Tanzania, facilitating direct discussion among regional, zonal, national, and international stakeholders on surveillance and outbreak preparedness. The conference's conclusions are relevant to strengthening health systems in other low- and middle-income countries.
BACKGROUND:It has been hypothesized that helminth infections increase HIV susceptibility by enhancing systemic immune activation and hence contribute to elevated HIV-1 transmission in sub-Saharan Africa.OBJECTIVE:To study systemic immune activation and HIV-1 co-receptor expression in relation to different helminth infections and in response to helminth treatment.METHODS:HIV-negative adults with (n = 189) or without (n = 57) different helminth infections, as diagnosed by Kato-Katz, were enrolled in Mbeya, Tanzania. Blinded to helminth infection status, T cell differentiation (CD45RO, CD27), activation (HLA-DR, CD38) and CCR5 expression was determined at baseline and 3 months after Albendazole/Praziquantel treatment. Plasma cytokine levels were compared using a cytometric bead array.RESULTS:Trichuris and Ascaris infections were linked to increased frequencies of "activated" CD4 and/or CD8 T cells (p<0.05), whereas Hookworm infection was associated with a trend towards decreased HLA-DR+ CD8 T cell frequencies (p = 0.222). In Trichuris infected subjects, there was a linear correlation between HLA-DR+ CD4 T cell frequencies and the cytokines IL-1β and IL-10 (p<0.05). Helminth treatment with Albendazole and Praziquantel significantly decreased eosinophilia for S. mansoni and Hookworm infections (p<0.005) but not for Trichuris infection and only moderately modulated T cell activation. CCR5 surface density on memory CD4 T cells was increased by 1.2-fold during Trichuris infection (p-value: 0.053) and reduced after treatment (p = 0.003).CONCLUSIONS:Increased expression of T cell activation markers was associated with Trichuris and Ascaris infections with relatively little effect of helminth treatment.
Sensitive diagnostic tools are crucial for an accurate assessment of helminth infections in low-endemicity areas. We examined stool samples from Tanzanian individuals and compared the diagnostic accuracy of a real-time polymerase chain reaction (PCR) with the FLOTAC technique and the Kato–Katz method for hookworm and the Baermann method for Strongyloides stercoralis detection. Only FLOTAC had a higher sensitivity than the Kato–Katz method for hookworm diagnosis; the sensitivities of PCR and the Kato–Katz method were equal. PCR had a very low sensitivity for S. stercoralis detection. The cycle threshold values of the PCR were negatively correlated with the logarithm of hookworm egg and S. stercoralis larvae counts. The median larvae count was significantly lower in PCR false negatives than true positives. All methods failed to detect very low-intensity infections. New diagnostic approaches are needed for monitoring of progressing helminth control programs, confirmation of elimination, or surveillance of disease recrudescence.
BACKGROUND:The intestinal nematode Trichuris trichiura is among the most common causes of human infectious disease worldwide. As for other soil-transmitted nematodes, its reproductive success and thus prevalence and intensity of infection in a given area strongly depend on environmental conditions. Characterization of the influence of environmental factors can therefore aid to identify infection hot spots for targeted mass treatment.METHODOLOGY:We analyzed data from a cross-sectional survey including 6234 participants from nine distinct study sites in Mbeya region, Tanzania. A geographic information system was used to combine remotely sensed and individual data, which were analyzed using uni- and multivariable Poisson regression. Household clustering was accounted for and when necessary, fractional polynomials were used to capture non-linear relationships between T. trichiura infection prevalence and environmental variables.PRINCIPAL FINDINGS:T. trichiura infection was restricted to the Kyela site, close to Lake Nyasa with only very few cases in the other eight sites. The prevalence of T. trichiura infection in Kyela was 26.6% (95% confidence interval (CI) 23.9 to 29.6%). Multivariable models revealed a positive association of infection with denser vegetation (prevalence ratio (PR) per 0.1 EVI units = 2.12, CI 1.28 to 3.50) and inverse associations with rainfall (PR per 100 mm = 0.54, CI 0.44 to 0.67) and elevation (PR per meter = 0.89, CI 0.86 to 0.93) while adjusting for age and previous worm treatment. Slope of the terrain was modelled non-linearly and also showed a positive association with T. trichiura infection (p-value p<0.001).CONCLUSION/SIGNIFICANCE:Higher prevalences of T. trichiura infection were only found in Kyela, a study site characterized by denser vegetation, high rainfall, low elevation and flat terrain. But even within this site, we found significant influences of vegetation density, rainfall, elevation and slope on T. trichiura infection. The inverse association of rainfall with infection in Kyela is likely due to the fact, that rainfall in this site is beyond the optimum conditions for egg development. Our findings demonstrate that use of remotely sensed environmental data can aid to predict high-risk areas for targeted helminth control.
Lipoarabinomannan (LAM), a cell wall component of mycobacteria, can be detected in the urine of tuberculosis (TB) patients. Advantages of this diagnostic include the ease of sample collection and test methods. However, as with most new TB diagnostics, LAM tests have been evaluated in well-controlled laboratory settings and subsequently need assessment under real working conditions. Our experience showed that the diagnosis of TB using the detection of LAM in urine under field conditions is prone to false-positive results due to contamination. Dust and soil, but also stool, seemed to lead to increased OD values and thus false-positive results of the enzyme-linked immunosorbent assay (ELISA) for LAM; however, contamination with blood, as well as bacterial or fungal organisms, had no influence. The collection of urine for the detection of LAM should therefore follow strict collection criteria in order to avoid contamination.
Background: Hookworm disease is one of the most common infections and cause of a high disease burden in the tropics and subtropics. Remotely sensed ecological data and model-based geostatistics have been used recently to identify areas in need for hookworm control.Methodology: Cross-sectional interview data and stool samples from 6,375 participants from nine different sites in Mbeya region, south-western Tanzania, were collected as part of a cohort study. Hookworm infection was assessed by microscopy of duplicate Kato-Katz thick smears from one stool sample from each participant. A geographic information system was used to obtain remotely sensed environmental data such as land surface temperature (LST), vegetation cover, rainfall, and elevation, and combine them with hookworm infection data and with socio-demographic and behavioral data. Uni- and multivariable logistic regression was performed on sites separately and on the pooled dataset.Principal Findings: Univariable analyses yielded significant associations for all ecological variables. Five ecological variables stayed significant in the final multivariable model: population density (odds ratio (OR) = 0.68; 95% confidence interval (CI) = 0.63-0.73), mean annual vegetation density (OR = 0.11; 95% CI = 0.06-0.18), mean annual LST during the day (OR = 0.81; 95% CI = 0.75-0.88), mean annual LST during the night (OR = 1.54; 95% CI = 1.44-1.64), and latrine coverage in household surroundings (OR = 1.02; 95% CI = 1.01-1.04). Interaction terms revealed substantial differences in associations of hookworm infection with population density, mean annual enhanced vegetation index, and latrine coverage between the two sites with the highest prevalence of infection.Conclusion/Significance: This study supports previous findings that remotely sensed data such as vegetation indices, LST, and elevation are strongly associated with hookworm prevalence. However, the results indicate that the influence of environmental conditions can differ substantially within a relatively small geographic area. The use of large-scale associations as a predictive tool on smaller scales is therefore problematic and should be handled with care.
Human immunodeficiency virus (HIV) DNA polymerase chain reaction (PCR) test using venous blood sample has been used for many years in low resource settings for early infant diagnosis of HIV infection in children less than 18 months. The aim of this study was to evaluate and compare the performance characteristics of Amplicor HIV-1 DNA assay version 1.5 following processing of venous blood and dried blood spot (DBS) samples by Roche manual DNA extraction and automated Roche MagNA Pure LC instrument (MP) for HIV-1 DNA PCR testing in Dar es Salaam, Tanzania, in order to scale up early infant diagnosis of HIV infection in routine practice. Venous blood samples from children under 18 months born to HIV-infected mothers between January and April 2008 were collected. Venous blood was used to prepare cell pellet and DBS samples. DNA extractions by manual procedure and MP were performed each on cell pellet, venous blood and DBS samples and tested by Amplicor HIV-1 DNA assay. Of 325 samples included, 60 (18.5%) were confirmed HIV-infected by manual extraction performed on cell pellets. Sensitivity of the assay following MP processing of venous blood was 95% (95% CI; 86.1-99.0%) and 98.3% (95% CI; 91.1 to 99.9%) for the manual extraction and processing by MP performed on DBS samples. Specificity of the assay with all DNA extraction methods was 99.6% (95% CI; 97.9 to 100%). Performance of the assay with Roche manual extraction and processing by MP on DBS samples compared well with Roche manual extraction performed on cell pellet samples. The choice of DNA extraction method needs to be individualized based on the level of laboratory facility, volume of testing and cost benefit analysis before it is adopted for use.