Cyanotoxins occurrence in drinking waters and risk of exposure to human in Ukerewe district Mwanza, Tanzania

A Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Doctor of Philosophy in Life Sciences of the Nelson Mandela African Institution of Science and TechnologyThere is global concern regarding the increase of cyanobacteria and cyanotoxins in freshwater and their potential effects on human health. This study was conducted to determine the occurrence of cyanotoxins and assessed their risk of exposure to human. A cross sectional study of 432 subjects was conducted to assess related health risk due to cyanobacteria and cyanotoxins exposure in selected villages of the Ukerewe District in Mwanza, Tanzania. A total of 138 water samples and 432 serum samples were collected in two phases (February and December). Thirteen cyanotoxins namely; Microcystins (-LA, -LF, -LR, -LY, -LW, -RR, -YR, -WR, dm MC-RR and dm MC-LR), anatoxin-a (AT-A), nodularin (NOD) and cylindrospermopsin (CYN) were assessed in water and in human serum by UPLC-MS/MS. Cylindrospermopsin was the most abundant cyanotoxin detected in the lake water samples in both phases. Microcystin (MC) congeners; -RR, -LR and –YR were detected in phase I while MC-RR and MC-LR were detected in phase II. No cyanotoxins were detected in wells and treated pipe water samples. Furthermore, phycocyanin concentration detected in Lake Victoria ranged from 5 to 58.4 μg/L which is above the WHO limit. The concentrations of cyanobacteria cells were beyond WHO acceptable limits. Species of Microcystis aeruginosa and Anabaena spp were identified as the most abundant cyanobacteria. Acute illnesses such as throat, eye, skin irritation and gastrointestinal illnesses were highly reported by lake water users as compared to wells and pipe water (P<0.001). Cyanotoxins of CYN, NOD and MCs congener (-LR, -RR and dmMC-LR) were detected in human serum. The concentration of CYN detected in humans ranged from 0.02 to 0.15 ng/mL and MCs ranged from 0.2 to 0.11 ng/mL. Concentration of cyanotoxin detected in human serum and liver biochemistry indices elevation, shows an association between the two with correlation coefficient of 0.33 for MC-LR while for combined cyanotixins of MC-LR, CYN and NOD is 0.78. This is the first study to report CYN, dm MC-LR and NOD in human serum, and CYN and NOD in freshwater of Lake Victoria. This study indicates the potential health risk of using lake water without any treatment for human consumption

A Framework for Timely and More Informative Epidemic Diseases Surveillance: The Case of Tanzania

This research article published by the Journal of Health Informatics in Developing Countries, 2018Background: A number of health facilities in the United Republic of Tanzania use different Hospital Management Information Systems (HoMISs) for capturing and managing clinical and administrative information for report generation. Despite the potentials of the data in the systems for use in epidemic diseases surveillance, timely extraction of the data for integrated data mining and analysis to produce more informative reports is still a challenge. This paper identifies the candidate data attributes for epidemic diseases surveillance to be extracted and analyzed from the Government of Tanzania Hospital Management Information System (GoT-HoMIS). It also examines the current reporting setup for epidemic diseases surveillance in Tanzania from the health facilities to the district, regional, and national levels. Methods: The study was conducted at the Ministry of Health, Community Development, Gender, Elderly, and Children (MoHCDGEC), Tumbi Designated Regional Referral Hospital (TDRRH), Muhimbili University of Health and Allied Sciences (MUHAS), and Mzumbe Health Centre, all in the United Republic of Tanzania. A total of 10 key informants (medical doctors, epidemiologists, and focal persons for various health information systems in Tanzania) were interviewed to obtain primary data. Data entry process in the GoT-HoMIS was also observed. Documents were reviewed to broaden understanding on several aspects. Results: All the respondents (100%) suggested patients’ gender, age, and residence as suitable attributes for epidemic diseases surveillance. Other suggested attributes were occupation (85.71%), diagnosis (57.14%), catchment area population (57.14%), vital status (57.14%), date of onset (57.14%), tribe (42.86%), marital status (42.86%), and religion (14.29%). Timeliness, insufficient immediate particulars on an epidemic-prone case(s), aggregated data limiting extensive analytics, missing community data and ways to analyze rumors, and poor data quality were also identified as challenges in the current reporting setup. Conclusion: A framework is proposed to guide researchers in integrating data from health facilities with those from social media and other sources for enhanced epidemic disease surveillance. Data entrants in the systems should also be informed on the essence and applications of data they feed, as quality data are the roots of quality reports

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

No abstract available

The need to improve access to rabies post-exposure vaccines: Lessons from Tanzania

Background Rabies is preventable through prompt administration of post-exposure prophylaxis (PEP) to exposed persons, but PEP access is limited in many rabies-endemic countries. We investigated how access to PEP can be improved to better prevent human rabies. Methods Using data from different settings in Tanzania, including contact tracing (2,367 probable rabies exposures identified) and large-scale mobile phone-based surveillance (24,999 patient records), we estimated the incidence of rabies exposures and bite-injuries, and examined health seeking and health outcomes in relation to PEP access. We used surveys and qualitative interviews with stakeholders within the health system to further characterise PEP supply and triangulate these findings. Results Incidence of bite-injury patients was related to dog population sizes, with higher incidence in districts with lower human:dog ratios and urban centres. A substantial percentage (25%) of probable rabies exposures did not seek care due to costs and limited appreciation of risk. Upon seeking care a further 15% of probable rabies exposed persons did not obtain PEP due to shortages, cost barriers or misadvice. Of those that initiated PEP, 46% did not complete the course. If no PEP was administered, the risk of developing rabies following a probable rabies exposure was high (0.165), with bites to the head carrying most risk. Decentralized and free PEP increased the probability that patients received PEP and reduced delays in initiating PEP. No major difficulties were encountered by health workers whilst switching to dose-sparing ID administration of PEP. Health infrastructure also includes sufficient cold chain capacity to support improved PEP provision. However, high costs to governments and patients currently limits the supply chain and PEP access. The cost barrier was exacerbated by decentralization of budgets, with priority given to purchase of cheaper medicines for other conditions. Reactive procurement resulted in limited and unresponsive PEP supply, increasing costs and risks to bite victims. Conclusion PEP access could be improved and rabies deaths reduced through ring-fenced procurement, switching to dose-sparing ID regimens and free provision of PEP

Evaluation of a point-of-use device used for autoantibody analysis and its potential for following microcystin leucine-arginine exposure

This research article was published in Frontiers in Sensors, Volume 5, 2024Introduction: Globally, the need for measuring exposure to algal toxins has become urgent due to ever-increasing reports of contamination in sea and freshwater, in shellfish and fish stocks and in aerosols. Methods: To address this issue, we evaluated the potential of determining autoantibodies to a panel of biomarkers known to be elevated following exposure to the hepatotoxin microcystin leucine-arginine. The presence of autoantibodies, specific to four selected stress-response, metabolomic and chaperone biomarkers, namely, Heat shock protein 1, Triosephosphate isomerase, Peroxiredoxin 1 and Peroxiredoxin 2 was employed in screening 371 serum samples from microcystin-exposed individuals in Tanzania. In addition, the capacity of the LightDeck fluorescence-based detector, a point-of-use device, to monitor these autoantibody responses in comparison to enzyme-linked immunosorbent assay was evaluated. Results: By using the determination of autoantibodies to this novel panel of biomarkers an altered response was observed following microcystin exposure, with levels generally upregulated. The presence of elevated levels of microcystin leucine-arginine in water, as well as in food sources in Tanzania, may potentially have significant health effects on the population. Discussion: This novel biomarker panel may have potential for the detection of microcystin leucine-arginine exposure as well as various microcystin exposure-associated cancers (e.g., hepatocellular cancer and colorectal cancer). In addition, the utilisation of the LightDeck point-of-use device proved successful for the rapid analysis of this biomarker panel

Evaluation of the influenza-like illness sentinel surveillance system: A national perspective in Tanzania from January to December 2019.

BackgroundThe World Health Organization (WHO) recommends periodic evaluations of influenza surveillance systems to identify areas for improvement and provide evidence of data reliability for policymaking. However, data on the performance of established influenza surveillance systems are limited in Africa, including Tanzania. We aimed to assess the usefulness of the Influenza surveillance system in Tanzania and to ascertain if the system meets its objectives, including; estimating the burden of disease caused by the Influenza virus in Tanzania and identifying any circulating viral strains with pandemic potential.MethodologyFrom March to April 2021, we collected retrospective data through a review of the Tanzania National Influenza Surveillance System electronic forms for 2019. Furthermore, we interviewed the surveillance personnel about the system's description and operating procedures. Case definition (ILI-Influenza Like Illness and SARI-Severe Acute Respiratory Illness), results, and demographic characteristics of each patient were obtained from the Laboratory Information System (Disa*Lab) at Tanzania National Influenza Center. The United States Centers for disease control and prevention updated guidelines for evaluating public health surveillance systems were used to evaluate the system's attributes. Additionally, the system's performance indicators (including turnaround time) were obtained by evaluating Surveillance system attributes, each being scored on a scale of 1 to 5 (very poor to excellent performance).ResultsA total of 1731 nasopharyngeal and oropharyngeal samples were collected from each suspected influenza case in 2019 from fourteen (14/14) sentinel sites of the influenza surveillance system in Tanzania. Laboratory-confirmed cases were 21.5% (373/1731) with a predictive value positive of 21.7%. The majority of patients (76.1%) tested positive for Influenza A. Thirty-seven percent of patients' results met the required turnaround time, and 40% of case-based forms were incompletely filled. Although the accuracy of the data was good (100%), the consistency of the data was below (77%) the established target of ≥ 95%.ConclusionThe overall system performance was satisfactory in conforming with its objectives and generating accurate data, with an average performance of 100%. The system's complexity contributed to the reduced consistency of data from sentinel sites to the National Public Health Laboratory of Tanzania. Improvement in the use of the available data could be made to inform and promote preventive measures, especially among the most vulnerable population. Increasing sentinel sites would increase population coverage and the level of system representativeness

Updated guidelines for evaluating public health surveillance systems.

Updated guidelines for evaluating public health surveillance systems.</p

Turnaround coverage among the sentinel sites of the National Influenza Sentinel Surveillance System (NISSS) in Tanzania, January to December 2019.

Turnaround coverage among the sentinel sites of the National Influenza Sentinel Surveillance System (NISSS) in Tanzania, January to December 2019.</p

The distribution of the SARI patients under the National Influenza Sentinel Surveillance System and the average samples collected per study sentinel sites in Tanzania, 2019.

The distribution of the SARI patients under the National Influenza Sentinel Surveillance System and the average samples collected per study sentinel sites in Tanzania, 2019.</p