In recent decades, the pervasive presence of antimicrobial pollutants in aquatic environments has emerged as a pressing global concern, with profound implications for environmental sustainability and public health ( Hossein & Ripanda, 2025 ). Antimicrobial pollution, refers to the environmental contamination resulting from the release of ntimicrobial agents such as antibiotics, antiviral, or antifungal in active form, their metabolites or transformational products into natural ecosystems as a result of anthropogenic activities including pharmaceutical industry, agriculture, aquaculture, healthcare systems, households and release of produced effluents ( Hossein et al., 2025 ; Ripanda, 2024 ). A recent study from East Africa indicated that Inadequate policy enforcement has been reported to result into improper disposal of pharmaceuticals, their metabolites and transformational products leading to, antibiotic resistance risks to human, other animal, and entire ecology ( Karungamye et al., 2022 ). Previous research examining trends in emerging pollution in Tanzania, noted preliminary studies on pharmaceuticals, endocrine-disrupting hormones, and disinfection by-products ( Miraji et al., 2016 ). These studies underscored the urgent need to expand monitoring efforts, enhance analytical infrastructure, and establish clear policies for managing emerging contaminants.

In Tanzania, a country with abundant freshwater resources critical for livelihoods, agriculture, and biodiversity conservation, the issue of antimicrobial contamination in surface waters ( Marijani, 2022 ; Ripanda et al., 2023c ), demands immediate attention. This work delves into the burgeoning problem of antimicrobial pollutants in Tanzania’s surface waters, shedding light on their occurrence, sources, and far-reaching environmental implications. Tanzania, like many developing countries, grapples with a myriad of challenges ( Achankeng , 2003 ; Zohoori & Ghani, 2017 ), ranging from rapid urbanization to inadequate waste management infrastructure. These challenges exacerbate the release of antimicrobial pollutants into surface waters through various pathways, including domestic, agricultural, industrial, and healthcare-related sources. A recent study by Kundu et al. (2024) , reported occurences of high levels of pharmaceuticals in the station downwards of a wastewater stabilization pond, discharging its partially treated effluent into the river, followed by stations whose rivers flowed through informal areas. Further sampled points’ located near the river’s water sources had fewer compounds with values below the detection limits, including amoxicillin, doxycycline, and sulfamethoxazole (94 ng/L) in the borehole, most of the concentrations detected in rivers were ten times higher than in boreholes ( Kundu et al., 2024 ). Even trace levels of antimicrobial pollutants pose public health risks by creating selective pressure that fosters the emergence and spread of antimicrobial-resistant pathogens through the food chain and clinical settings, impairing ecological health.

A study by Ripanda et al. (2023c) , revealed a significant role of urban wastewater as a reservoir of resistant bacteria and genes, particularly in resource limited settings including Tanzania. The prevalence of multidrug resistance (MDR) bacteria, especially E. coli, and the presence of resistance genes such as Sul and Tet families highlight a growing threat of resistant infections ( Ripanda et al., 2023c ). The detection of β-lactamase-producing isolates further complicates treatment options, given their ability to deactivate critical antibiotic classes.

Antimicrobial pollutants such as antibiotics from human and veterinary use, and agricultural runoff from livestock farming and crop cultivation practices introduces pollutants into rivers and lakes ( Mdegela et al., 2021 ; Mwega et al., 2020 ). Similarly, industrial effluents from pharmaceutical manufacturing and healthcare facilities discharge potent antimicrobial compounds into water bodies ( Adeola & Forbes, 2022 ; Ripanda et al., 2025 ), compounding the contamination burden. The impacts of antimicrobial pollution in Tanzanian surface waters are far-reaching, extending beyond ecological harm to include significant public health and economic consequences. A particularly concerning outcome is the intensification of antimicrobial resistance (AMR), a global health threat undermining the effectiveness of life-saving antibiotics. The continuous exposure of aquatic microorganisms to sub-lethal concentrations of antimicrobial agents fosters the selection of resistant strains, potentially compromising the effectiveness of medical treatments and increasing healthcare costs. A study by Hounmanou et al. (2019) , revealed the presence of toxigenic Vibrio cholerae O1 strains in Lake Victoria during a non-outbreak period, demonstrating their environmental persistence and pathogenic potential. Identified strains harbored major virulence genes (like ctxA, ctxB, zot, tcpA) and pathogenicity islands (like VPI-1, VPI-2, VSP-1, VSP-2) ( Hounmanou et al., 2019 ), which are critical for disease causation. The identified strains possessed genes for biofilm formation, stress response, and quorum sensing, enhancing survival in aquatic environments. The genes carried the SXT integrative conjugative element, conferring MDR to aminoglycosides, sulfamethoxazole, trimethoprim, phenicol, and quinolones ( Hounmanou et al., 2019 ). This indicates dual threats of cholera outbreaks and AMR posed by these persistent environmental strains, requiring intervention.

Figure 1 presents structures of selected antimicrobial pollutants and other reported pharmaceutical contaminants. A study by Kimera et al. (2021) , revealed that among recovered isolates, 45.5% were Klebsiella pneumoniae and 29.6% were Escherichia coli. Resistance patterns varied across different environments. For instance, K. pneumoniae showed higher resistance in effluent (27.9%) compared to E. coli (26.6%), while E. coli exhibited greater resistance in river water, sediment, and crop soil (35% vs. 25%) ( Kimera et al., 2021 ). Notably, K. pneumoniae showed high resistance to nalidixic acid (54.6%) and ciprofloxacin (33.3%), whereas E. coli displayed significant resistance to ciprofloxacin (39.7%) and trimethoprim/sulfamethoxazole (38%) ( Kimera et al., 2021 ). Resistance levels increased downstream, from 28.3% in Kisarawe to 66.7% in Upanga West. About 53.2% isolates possessed MDR genes, especially extended-spectrum beta-lactamase (ESBL), quinolone-resistant, and carbapenem-resistant strains ( Kimera et al., 2021 ).

A study by Marijani (2022) highlighted a significant bacterial contamination in fish from botopen-air markets and supermarkets, with E. coli being the most prevalent species (40% in open-air markets, 37% in supermarkets), followed by

Klebsiella spp., Salmonella spp., and other pathogens like Shigella spp., Citrobacter spp., and Pseudomonas spp. While 58.7% of the samples met the International Commission on Microbiological Specifications for Foods criteria as “good,” 41.3% were only marginally acceptable ( Marijani, 2022 ). Particularly, isolates of E. coli and Salmonella spp. exhibited resistance to multiple antibiotics ( Marijani, 2022 ), including penicillin, erythromycin, gentamicin, and tetracycline, threatening public health. A study by Moremi et al. (2016b) revealed the presence of multiple antibiotic resistance genes such as sulfonamides (sul1/sul2), tetracyclines (tet(A)/tet(B)), fluoroquinolones (aac(6′)-Ib-cr, qnrS1), aminoglycosides (aac(3)-lld, strA, strB), and trimethoprim (dfrA14) in bacterial isolates from the environment and fish. Notably, E. coli sequence types ST-38 and ST-5173 were detected in isolates from the environment and fish, suggesting a potential link between environmental and food-chain contamination, threatening public health. The identification of IncY plasmids carrying key resistance genes (blaCTX-M-15, qnrS1, strA, strB) in environmental isolates and fish ( Moremi et al., 2016b ), highlighting the role of plasmid-mediated dissemination in spreading resistance as reported by Hossein and Ripanda (2025) . This suggests that resistant E. coli from Mwanza city’s sewage system may be entering Lake Victoria, highlighting the close link between human activities, environmental contamination, and the food chain.

The continued presence of bla_CTX-M-15 in this ecosystem is driven by both the clonal spread of resistant strains and horizontal gene transfer via IncY plasmids, underscoring the urgent need for integrated strategies to combat antibiotic resistance, Further studies indicated growing trends of bacterial infections in fish farms and will continue to be an issue of concern into the future ( Marijani, 2022 ; Mdegela et al., 2021 ; Mzula et al., 2019, 2021 ), which may increase the use of antimicrobial agents requiring intervention. These findings pose a public health risk, particularly to immunocompromised individuals, emphasizing the need for improved food safety measures, regular AMR monitoring, and consumer education on safe handling practices to mitigate health hazards.

In Tanzania AMR pollution is a significant issue, driven by widespread use of antibiotics in healthcare, agriculture, and community settings. Recent data indicates that in 2019, Tanzania reported approximately 12,500 deaths attributable to AMR and 54,000 deaths associated with drug-resistant infections ( Evaluation, 2023 ). The primary pathogens contributing to these outcomes include Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, and Salmonella Typhi, which are linked to respiratory, bloodstream, and intra-abdominal infections ( Camara et al., 2023 ; Evaluation, 2023 ; Mbwasi et al., 2020 ; Mdegela et al., 2021 ). Tanzania ranks 30th globally for AMR-related age-standardized mortality rates, highlighting its substantial burden compared to other regions ( Evaluation, 2023 ). Efforts are underway to address the issue through national AMR action plans, though challenges remain in data collection, surveillance, and resource allocation. Moreover, the presence of antimicrobial pollutants can disrupt aquatic ecosystems, leading to biodiversity loss, altered nutrient cycling ( Bashir et al., 2020 ; Wang et al., 2023 ), and the proliferation of harmful algal blooms. These ecological disruptions cascade through food webs, affecting fisheries, agriculture, and tourism-dependent livelihoods, thus underscoring the interconnectedness of environmental health and socio-economic well-being ( Achankeng , 2003 ; Bashir et al., 2020 ; Wang et al., 2023 ).

Additionally, the contamination of surface waters poses direct risks to human health, as communities reliant on these water sources for drinking, cooking, and irrigation may be exposed to antimicrobial residues and resistant bacteria, leading to waterborne diseases and treatment challenges. Addressing the complex challenge of antimicrobial pollution in Tanzanian surface waters necessitates a multi-faceted approach encompassing scientific research, policy interventions, community engagement, and capacity-building initiatives. Robust monitoring programs are essential to assess the extent of contamination, identify hotspots, and track temporal trends, enabling evidence-based decision-making and targeted mitigation efforts. The findings emphasize the urgent need for improved wastewater management, monitoring of AMR genes in environmental reservoirs, strengthened antibiotic stewardship and surveillance programs to curb AMR transmission to humans and other animals. Appendix Table A1 presents selected employed antimicrobial agents during this period in Tanzania, category, structure, reported environmental effects and its implications, in some cases combinations of these agents are employed ( Sangeda et al., 2021 ). Together, sulphonamides and trimethoprim are often used in combination (e.g., co-trimoxazole) because they act synergistically to inhibit folic acid synthesis at two different points in the pathway, making the treatment more effective and reducing the likelihood of resistance development.

Origin of antimicrobial pollution

The release of effluents containing antimicrobial agents such as such as penicillin and erythromycin for bacterial infections ( Pérez-Legaspi & Rico-Martínez, 2023 ; Rugumisa et al., 2016 ), antivirals such as lamivudine and oseltamivir for viral infections ( Huang et al., 2021 ), antifungals such as fluconazole for fungal infections ( Lu et al., 2021 ), and antiparasitic drugs such as chloroquine for malaria ( Meo et al., 2020 ) is of public health concern, referred to antimicrobial pollution. These drugs are crucial in the treatment and prevention of various infectious diseases ( Pérez-Legaspi & Rico-Martínez, 2023 ; Rugumisa et al., 2016 ). Report indicate an increase in global antibiotic consumption rate by 46% in 2018 compared to that of 2000 ( Browne et al., 2021 ). Studies indicate that 30 to 90% of consumed drug is excreted through urine or faeces ( Bamfo et al., 2021 ; Daghrir & Drogui, 2013 ; Egan et al., 2000 ), indicating that approximately more than 90 thousand tons may end up in the environment especially aquatics. Further, between 2010 and 2017, Tanzania utilized a cumulative total of 13390.32 tonnes of antibiotics ( Hamim et al., 2021 ), equivalent to about 1675 tonnes per year. This indicates introduction of more than 500 tonnes of antibiotics per year in the environment especially water bodies, which may impact ecological health. Table A2 showcases comprehensive data on AMR pollution in various environmental compartments in Tanzania. This includes the concentrations of antimicrobials where available, the presence of antimicrobial-resistant microbes, and the detection of resistance genes. The table highlights findings from wastewater, surface waters, urban receiving waters, effluents, and the food chain. This data is crucial for understanding the extent of antimicrobial contamination and the spread of resistance. The table underlines the pervasive nature of antimicrobial pollution and its potential public health impacts. The presence of resistant microbes and genes in these environments indicates the ongoing risk of AMR spreading through environmental and food pathways. This information is vital for developing strategies to mitigate AMR and safeguard environmental and human health.

Similarly, over the course of eight years (2010 to 2017), there was a significant level of systemic antivirals usage, reaching 367.1 and antifungals 10.8 defined daily doses (DDD), per 1000 inhabitants per day ( Hamim et al., 2021 ). This indicates introduction of more than 110 defined daily doses of antiviral and 3 defined daily doses of antifungal per 1000 inhabitants per day into the environment. A similar study reported average daily defined dose (DDD) per 1,000 inhabitants for all antimicrobials was 80.8 ± 39.35. The DDD per 1,000 inhabitants per day (DDD/1000/D) decreased significantly from 136.41 in 2017 to 54.98 in 2018 and further to 51.02 in 2019 ( Mbwas i et al., 2020 ). Doxycycline, amoxicillin, and trimethoprim-sulfamethoxazole were the most used antibiotics during this period, with DDD/1,000/D values of 20.01, 16.75, and 12.42, respectively ( Mbwas i et al., 2020 ).

Most recommendations of antimicrobial agents use in Tanzania is done by the private medical sector, this is evidenced by an annual increase in its share from 2017 to 2019 ( Mbwa si et al., 2020 ). Over 90% of the antimicrobials consumed were classified as access class medications, while class medications made up less than 10% and 1% of reserve class medications. The private sector use of antimicrobials is rising significantly and needs to be closely monitored in line with national policies to ensure ecological safety and sustainability. Report indicates lack of information on antimicrobial consumption patterns in sub-Saharan Africa, this requires intervention. On the other hand, guidelines for disposal of expired or unused medication are only available for public premises and hospitals dis regarding households, leading to pollution as people discards together with domestic wastes or pit latrines ( Karungamye et al., 2022 ; Banaga, 2020 ). AMR pollution not only poses a direct threat to ecosystems and human health but also exacerbates the problem of AMR in clinical settings.

This narrative literature review examines antimicrobial pollution in Tanzanian surface waters, focusing on regions with available data on the prevalence of resistance and associated genes in various environmental matrices, including surface water, groundwater, wastewater effluents, sediments, soils, and the food chain, as detailed in Table A2 . The review draws on journal articles sourced from multiple databases, including Web of Science, Scopus, Google Scholar, Wiley Online Library, ScienceDirect, Taylor & Francis Online, Sage Publishing, and PubMed. By compiling and analyzing data from studies across Tanzania, this review provides insights into the antimicrobial pollution in Tanzanian surface waters focusing on the sources, environmental risks, and public health implications, an area that remains underexplored in existing literature.

The global nature of AMR pollution means that resistant microorganisms, along with resistance genes, can traverse borders, posing a transboundary threat to public health. The interconnectedness of ecosystems and the movement of people and goods make this issue difficult to contain within national boundaries. The prevalence of AMR in the environment ultimately affects clinical care, as infections caused by resistant pathogens become harder to treat. There is limited data highlighting the status of AMR pollution on Tanzania aquatic environments ( Joachim et al., 2023 ; Kimera et al., 2021 ; Subbiah et al., 2020 ), but AMR pollution is transboundary and there are reports of diseases as a result of resistant strains of microbs. A study by Kimera and Coallegues reported that among the recovered isolates, 45.5% were Klebsiella pneumoniae and 29.6% were Escherichia coli. K. pneumoniae showed greater resistance in effluent (27.9%) compared to E. coli (26.6%) ( Kimera et al., 2021 ). However, E. coli exhibited higher resistance in river water, sediment, and crop soil compared to K. pneumoniae (35% vs. 25%, respectively) ( Kimera et al., 2021 ). K. pneumoniae had the highest resistance to nalidixic acid (54.6%) and ciprofloxacin (33.3%), while E. coli was most resistant to ciprofloxacin (39.7%) and trimethoprim/sulfamethoxazole (38%) ( Kimera et al., 2021 ). Resistance increased from 28.3% in Kisarawe, where the river originates, to 59.9% in Jangwani (middle section) and 66.7% in Upanga West, where the river enters the Indian Ocean ( Kimera et al., 2021 ). Further, of the E. coli and K. pneumoniae isolates, 53.2% were resistant to more than three classes of antibiotics, with higher occurrence among ESBL producers, quinolone-resistant, and carbapenem-resistant strains.

A study by Silago and Colleagues investigated multidrug-resistant uropathogens causing community acquired urinary tract infections among patients attending health facilities in Mwanza and Dar es Salaam, and reported that Staphylococcus aureus and Staphylococcus haemolyticus were the predominant ( Silago et al., 2022 ). Escherichia coli exhibited resistance ranging from 0.7% (meropenem) to 86.0% (ampicillin), while other Enterobacterales showed resistance from 0.0% (meropenem) to 75.6% (ampicillin). Multidrug resistance was observed in 45.4% of Enterobacterales and 22.4% of Gram-positive bacteria p-value = 0.008 ( Silago et al., 2022 ). Overall, sulfamethoxazole emerged as the most frequently identified compound in surface water across Africa, ranging from 0.00027 to 39 μg/L ( Faleye et al., 2018 ), in recent study sulfamethoxazole (94 ng/L) was identified in the borehole, with most detected pollutants in rivers being ten times higher than in boreholes ( Kundu et al., 2024 ), including report of resistance to sulfamethoxazole ( Baniga et al., 2020 ; Ripanda, 2024 ; Ripanda et al., 2023c ). Further, Efavirenz and nevirapine exhibit notable persistence in effluents and are prevalent in surface water based on environmental concentrations. Elevated levels of resistance to penicillin G, chloramphenicol, streptomycin, and oxytetracycline have been documented, among pathogenic microbial communities in dairy cattle suffering from mastitis ( Mdegela et al., 2021 ). Similar patterns are observed in poultry, where both eggs and meat are contaminated with Escherichia coli strains resistant to amoxicillin + clavulanate, sulphamethoxazole, and neomycin ( Mdegela et al., 2021 ). Furthermore, a growing trend of emerging multidrug-resistant E. coli, and Klebsiella pneumoniae, has been observed in food animals. Reports also indicate an uptick in methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase (ESBL) in the livestock sector in Tanzania ( Mdegela et al., 2021 ).

Antimicrobial pollutants enter and circulate in the environment, potentially bioaccumulate in living tissues, bioconcentrates in living organisms and biomagnifies through food chain ( Hossein et al., 2023 ), while creating harm to exposed organism. The presence of antimicrobial pollutants in the environment is linked to deterioration of ecosystem health and increased diseases ( Martins et al., 2012 ; Omotola et al., 2021 ). Other pathways by which antimicrobials are introduced into the environment include improper disposal of leftover and expired drugs in water stream or down the toilet, chemical waste from manufacturing facilities, and municipal landfill leachates ( Miraji et al., 2016 ; Sorensen et al., 2014 ), aquaculture, and animal systems ( Gwenzi et al., 2020 ). Less-explored yet potentially significant sources include non-engineered landfills, on-site sanitation facilities, funeral parlors, and gravesites ( Gwenzi et al., 2020 ). Once these chemicals are in the environment, they can flow from one compartment to another while creating harm. However, the drawbacks of antimicrobials in the environment extend beyond acute effects to delayed effects from bioaccumulation, amplified effects from drug-drug interactions, aggravation of drug resistance, and reduction in aquatic and terrestrial food production ( Kamba et al., 2017 ). Figure 2

presents reported sources of antimicrobial pollutants including agronomic activities ( Mdegela et al., 2021 ), direct disposal ( Chengula et al., 2015 ; Kihampa, 2013 ), effluents ( Bidu et al., 2021 ; Miraji et al., 2016 ), therapeutic use including disposal practices ( Gwenzi et al., 2023 ; Millanzi et al., 2023 ; Minzi & Manyilizu, 2013 ), indicating human is the source and sink of antimicrobial and other emerging pollutants.

This may lead to antimicrobial pollution and dissemination of antimicrobial resistant pathogens leading to increased hospitalization ( Kumburu et al., 2017 ; Mikomangwa et al., 2020 ; Moremi et al., 2016a ; Seni et al., 2019b ), mortality rates ( Blom berg et al., 2007 ; Manyahi et al., 2020 ; Seni et al., 2019a ; Seni et al., 2019b ), and overall degradation of ecological balance ( Karungamye et al., 2023 ; Kümmerer , 2009, 2011 ; Miraji et al., 2016 ; A. Ripanda et al., 2023b ; Ripanda et al., 2024 ; Ripanda et al., 2023c ). After their introduction into the environment ( Ripanda et al., 2023c ; Subbiah et al., 2020 ), they persist while circulating in environmental compartments such as soil , water ( Hossein et al., 2018 ; Ripanda et al., 2023c ), sediments ( Kimera et al., 2021 ; Sabatino et al., 2024 ), crops ( Kimera et al., 2021 ), creating harm and flow including through good chain ( Azabo et al., 2022 ; Ripanda et al., 2022 ; Sonola et al., 2021a ; Sonola et al., 2021b ; Subbiah et al., 2020 ). Further the results of environmental risk assessment and routine environmental monitoring regulations do not include antimicrobial pollutants, simply because acute risk assessments show insignificant human health hazards, this may lead to antimicrobial pollution. The presence of antimicrobial pollutants in waters, aquatic ecosystems, and other environmental compartment have been reported globally ( Atnafie et al., 2021 ), with scarcity of information from developing countries as a result of limited fund to purchase or manage the state of art equipment necessary for their isolation, identification, and quantification.

Most reported antimicrobial pollutants include antibiotics such as ciprofloxacin ( Ripanda et al., 2024 ), and anti-retroviral drugs such as lamivudine ( Ripanda et al., 2023a, 2023b ), are considered active once in the environment. A load of antimicrobial residues released into the environment after anthropogenic usage has been linked to both human and environmental health degradation. Although antimicrobials are of public health concern, they are currently neither monitored nor included in the environmental guidelines in most countries. These chemicals are environmentally persistent and have tendency to bioconcentrate, bioaccumulate and biomagnify through food chain while causing potential environmental risk especially when such chemicals come into contact with drinking water supplies and the food chain ( Abelkop et al., 2018 ).

Robinson H. Mdegela et al. (2021) , reported that microorganisms, including bacteria, along with their residues, can disseminate through food, water, and the environment, creating a One Health risk pathway that connects other animals, humans, and ecosystems. This pathway also facilitates the potential spread of resistance through travel, trade, and interactions at the interfaces between domestic animals, wildlife, and humans. A recent survey in Tanzania found residues of the human designated antiviral agent lamivudine in animal feeds and tissues of domestic pigs and broiler chickens ( Kimera et al., 2025 ). This indicates the potential for these pollutants to be disseminated through the food chain, impairing ecological and public health. Antimicrobial agents such as lamivudine and ciprofloxacin and their residues can exert a wide range of ecotoxicological effects on aquatic organisms, influencing physiological, biochemical, and community-level processes as a result of single or mixture of drugs ( Alderton et al., 2021 ; Fernandez et al., 2021 ; Michael et al., 2014 ).

In the treatment of medical conditions antimicrobials, including antibiotics, play a vital role, but, according to WHO, AMR has been declared a major threat to public health and is predicted to cost about 10 million lives a year by 2050. Reports of occurrences of substances such as antimicrobial pollutants, and other emerging contaminants in the environment including surface waters are globally available ( Groot & van’t Hooft, 2016 ; Hong et al., 2013 ; Wu et al., 2016 ), including Tanzania ( Hossein et al., 2018 ; Hounmanou et al., 2019 ; Kimera et al., 2021 ; Marijani, 2022 ; Moremi et al., 2016b ; Mzula et al., 2019 ), this calls for remediation of these contaminants for ecological safety.

Research laboratories demonstrated growth inhibition in microalgae Pseudokirchneriella subcapitata sunder short-term exposures to ciprofloxacin than Daphnia magna and Gambusia holbrooki ( Martins et al., 2012 ), reduced reproduction in crustaceans Daphnia magna ( Martins et al., 2012 ), and oxidative stress in fish species such as Danio rerio ( Batir-Marin et al., 2025 ). Report of adverse impact on the root lengths on exposure to lamivudine was recorded for Allium cepa, evidenced by chromosomal aberration in the exposed Allium cepa root tips ( Omotola et al., 2021 ). These effects collectively indicate the potential of antimicrobials to disrupt aquatic food webs, nutrient cycling, and ecosystem resilience. However, most ecotoxicological data are derived from temperate model organisms that may not accurately represent tropical aquatic systems.

According to Moffo et al. (2024) , the use of antimicrobial agents in production systems and resistance in African fish present a growing public health challenge with direct implications for the One Health framework. The meta-analysis revealed higher pooled prevalence of resistance among bacterial isolates, particularly Escherichia coli showing 87.1% resistance to ampicillin, with widespread multidrug resistance to commonly used antimicrobials including cotrimoxazole, gentamicin, tetracycline, and amoxicillin ( Moffo et al., 2024 ). Such resistant strains can be transmitted to humans through the consumption of contaminated fish, contact with aquaculture water, or their environmental dissemination through effluents, thereby undermining the efficacy of critical antibiotics used in clinical settings leading to health degradation. Poor adherence to withdrawal periods and off-label antimicrobial use which increase the likelihood of drug residues in fish and aquatic environments was also highlighted, indicating the potential for consumers to be exposed to the residues and associated health impact. These residues not only pose toxicological risks but also create selective pressure that drives the persistence of resistant bacteria in natural environments. Results of surveillance of Msimbazi River Basin in Tanzania, revealed widespread antimicrobial resistance among Enterobacteriaceae, particularly E. coli and K. pneumoniae ( Kimera et al., 2021 ), isolates were multidrug-resistant, with high prevalence of ESBL, quinolone, and carbapenem resistance. This indicates potential for degradation of ecological health, highlighting critical environmental dissemination of AMR and underscore the urgent need to control antimicrobial pollution within the basin. In Tanzania ( Kilusungu et al., 2024 ; Mramba & Kahindi, 2023 ) and other Sub-Saharan African countries, where aquaculture contributes substantially to food security and livelihoods, this situation threatens both public health and economic stability, emphasizing the urgent need for integrated antimicrobial use (AMU) and AMR surveillance, regulatory enforcement, and responsible antimicrobial stewardship in line with One Health principles to ensure ecological safety.

Furthermore, antimicrobial pollutants may induce selective pressure on microbial communities, promoting the proliferation of resistant microorganism such as antibiotic-resistant bacteria and genes within sediments and water columns. This process creates a feedback loop that links environmental health to human and animal health a central concern under the One Health framework. Considering limited wastewater treatment capacity and the close human, livestock, wildlife-water interface, the ecological risks associated with antimicrobial pollution are particularly pronounced. Therefore, localized ecotoxicological studies using native species and realistic environmental concentrations are essential to assess ecological vulnerability and to guide mitigation and policy interventions.

The environmental AMR pollution, including resistance genes are linked to clinical outcomes, and in Tanzania is becoming increasingly evident. Studies have revealed that resistance determinants such as bla-CTX-M, bla-SHV, and bla-NDM detected in Escherichia coli and Klebsiella spp. isolated from rivers, wastewater, and livestock environments are genetically similar to those identified in clinical isolates from major hospitals in Dar es Salaam, Mwanza, and Arusha. This overlap suggests continuous exchange of resistance genes between environmental reservoirs and human populations through contaminated water, food, and direct contact. The persistence of these resistance elements in surface waters and sediments not only heightens infection risks but also complicates treatment outcomes in healthcare settings, requiring intervention. Strengthening integrated AMR surveillance that links environmental sampling with hospital microbiology data is therefore vital to fully operationalize One Health AMR framework in Tanzania, enabling timely, evidence-based interventions across sectors.

In Tanzania, the regulatory and management framework for AMR is designed to address the growing threat through a coordinated, multi-sectoral approach. The framework is guided by the National Action Plan (NAP), which aligns with the Global Action Plan on AMR endorsed by the WHO ( Munkholm & Rubin, 2020 ; Neale & Cullen, 2024 ). The key elements of the AMR framework include the NAP, first NAP on AMR was launched its in 2017, covering a five-year period (2017-2022), with ongoing efforts to update and extend the plan ( Frumence et al., 2021 ). The NAP focuses on improving awareness and understanding of AMR, strengthening knowledge through surveillance and research, reducing the incidence of infection, optimizing the use of antimicrobial agents, and ensuring sustainable investment in AMR initiatives ( Frumence et al., 2021 ). Tanzania Medicines and Medical Devices Authority (TMDA) is responsible for regulating the quality, safety, and efficacy of medicines, including antimicrobials ( Mbwasi et al., 2020 ). TMDA oversees the registration, distribution, and use of antibiotics in both human and veterinary medicine. Whereas the Ministry of Health (MoH) oversees the implementation of AMR policies and strategies ( Frumence et al., 2021 ), including infection prevention and control (IPC) programs in healthcare settings. Tanzania Veterinary Laboratory Agency (TVLA) is involved in the regulation of antimicrobial use in animals and ensuring compliance with veterinary guidelines ( Mkopi et al., 2024 ). Tanzania has established an integrated surveillance system for AMR, which includes the collection and analysis of data from both human health and animal health sectors. This system is critical for tracking resistance patterns and informing policy decisions.

Similarly, the country has developed a network of laboratories capable of detecting AMR, which plays a key role in monitoring resistance trends and guiding treatment protocols ( Camara et al., 2023 ). The implementation of IPC programs in hospitals and clinics to reduce the spread of infections and promote the rational use of antimicrobials, will be of help to mitigate the negative effects on these substances on environment and health. Public health campaigns and community outreach programs aim to educate the public on the risks of AMR and promote good hygiene practices ( Ashley et al., 2016 ; Mudenda et al., 2023 ). Tanzania has laws and regulations that control the sale and use of antibiotics, particularly focusing on preventing over-the-counter sales without a prescription ( Chuwa et al., 2024 ; Ndaki et al., 2021 ). Also, there are specific guidelines for the prudent use of antimicrobials in animals to prevent the emergence of resistance in zoonotic pathogens. In Tanzania AMR framework is built on a One Health approach, involving collaboration between human health, animal health, and environmental sectors. This approach ensures that AMR is addressed comprehensively across different sectors. Further, universities and research institutions in Tanzania contribute to the AMR framework by conducting studies on resistance mechanisms, developing new diagnostics, and evaluating the effectiveness of AMR interventions. Tanzania collaborates with international organizations such as WHO, the Food and Agriculture Organization (FAO), and the World Organisation for Animal Health (OIE) to strengthen its AMR response and align with global best practices to ensure ecological health and sustainability.

Curbing AMR pollution in Tanzania requires not only scientific and policy interventions but also a transformative behavior change across communities ( Durrance-Bagale et al., 2021 ; Frumence et al., 2021 ). Through the World AMR Awareness Week (WAAW), Tanzania has amplified national efforts to educate the public on the prudent use of antimicrobials in human, animal, and environmental health sectors ( Fuller et al., 2023 ; Mathobela, 2025 ; Mramba et al., 2025 ). The Tanzania Parliamentarian Alliance for AMR has been instrumental in driving political commitment and advocating for evidence-based policies that strengthen antimicrobial stewardship and environmental protection. Complementing these initiatives, grassroots campaigns such as “Healthy Farming-No AMR” promote responsible antibiotic use among livestock farmers by encouraging biosecurity, hygiene, and vaccination as alternatives to routine antimicrobial use. Similarly, the “Holelaholela Itakucost” campaign uses culturally resonant messaging to warn against careless antibiotic consumption and disposal, linking everyday behavior to the growing AMR crisis. Together, these efforts underscore the power of coordinated awareness, policy advocacy, and behavioral change in reducing AMR pollution and safeguarding public health in Tanzania.

Tanzania has emerged as a continental leader in promoting antimicrobial resistance (AMR) awareness through the annual commemoration of World AMR Awareness Week (WAAW), coordinated by the Ministry of Health in collaboration with key One Health partners. The country’s role as host of the 7th Africa Continental WAAW Campaign, planned for November 2025 in Dar es Salaam, underscores its growing regional influence in AMR advocacy and policy dialogue. WAAW events in Tanzania bring together diverse stakeholders—including human and animal health professionals, environmental experts, researchers, policymakers, and the public to promote responsible antimicrobial use, infection prevention, and biosecurity best practices. This multi-sector engagement not only reinforces Tanzania’s One Health approach but also translates global AMR commitments into community-level action and behavioural change. Through such sustained annual campaigns, Tanzania continues to demonstrate how coordinated public awareness can catalyse national and regional progress in AMR mitigation.

The “Healthy Farming-No AMR” campaign, organised by the One Health Society, Tanzania and supported by the Trinity Challenge, is one example of a community-driven effort to combat AMR focusing on the livestock, environment-human interface. This campaign was conducted between June and November 2025 across the Dar es Salaam and Pwani regions in the eastern costal part of Tanzania, using integrated One Health approach to transform livestock production practices through behaviour change, education, and innovation. The campaign engaged livestock farmers, veterinarians, feed suppliers, and community leaders, to promote prudent antimicrobial use, improved biosecurity, and environmentally sustainable farming. The campaign focus on co-designing solutions with farmers showing workable alternatives like improved record-keeping, vaccination, and hygiene lessen reliance on antibiotics. The campaign further links farm-level stewardship with environmental protection by addressing antimicrobial pollutants in effluents and animal waste, reinforcing that responsible farming is not only vital for animal health and productivity but also for safeguarding ecosystems and public health. These locally tailored, evidence-informed interventions can operationalize One Health principles for real-world AMR mitigation in Tanzania.

The Tanzania Parliamentarian Alliance for AMR, an initiative led by the One Health Society-Tanzania (OHS), marks a transformative step toward embedding antimicrobial resistance (AMR) governance into the country’s political and legislative framework. By strategically engaging Members of Parliament, the initiative fosters political will, policy coherence, and resource mobilization to strengthen Tanzania’s multisectoral AMR response. Drawing on OHS’s advocacy evidence and the National Action Plan on AMR (2017-2022), the alliance empowers legislators to champion laws that regulate antimicrobial use across human health, veterinary, and environmental sectors aligning with the Global Action Plan on AMR (WHO, FAO & OIE). Its innovation lies in bridging the gap between science and policy, ensuring parliamentary committees integrate AMR oversight within public health, agriculture, and environmental governance agendas. This political stewardship model demonstrates how Tanzania is institutionalizing the One Health approach through legislative engagement, fostering accountability and sustainability in AMR mitigation.

In Tanzania, the “Holela-holela Itakukosti” campaign literally translated as “Recklessness Will Cost You”, which is most creative and impactful public health initiatives addressing AMR. This is collaborative campaign between the Government of Tanzania through Office of the Prime Minister, One Health Section, Ministries of Health, Livestock, Fisheries, and Environment, United States Agency for International Development (USAID), and the Johns Hopkins Center for Communication Programs (CCP) ( Desmon, 2024 ), launched under the One Health framework. The campaign blends science-based messaging with culturally resonant communication strategies to shift public behaviour around antibiotic usage. The campaign reframes AMR as not only a medical but also social and economic issue that affects families, farmers, and entire ecosystems, through the use of mass media, social influencers, community dialogues, and an engaging mascot representing “responsible medicine”. “Holela-holela Itakukosti” is an example of innovation in public engagement that integrates messages on human, animal, and environmental health to transform AMR into relatable everyday actions such as completing prescriptions, avoiding self-medication, and maintaining hygiene in livestock management, aiding in the combat to ensure ecological safety.

This participatory approach empowers communities to become stewards of antimicrobial stewardship, making it a model for AMR mitigation efforts across Africa. Preliminary descriptive data suggest that the ‘Holela-Holela Itakukosti’ campaign engaged a broad audience: for example, media reports cite approximately 24.7 million listeners reached and over 23 million social-media account users exposed to campaign content. Although these figures point to high reach and favourable expert endorsement, many countries within the East, Central and Southern African region have expressed interest in emulating it, rigorous publicly‐available evaluation data on sustained behaviour change, antimicrobial consumption or reduction in misuse remain limited.

Tanzania faces significant challenges in combating AMR, primarily due to inadequate regulation, overuse of antibiotics, and limited public awareness ( Camara et al., 2023 ; Mbwasi et al., 2020 ; Ndaki et al., 2021 ). A key issue is the widespread use of antibiotics in agriculture ( Mdegela et al., 2021 ), and human health ( Mbwasi et al., 2020 ; Mdegela et al., 2021 ; Ndaki et al., 2021 ), without proper oversight, contributing to the rapid emergence of resistant strains. Studies have shown that antibiotic residues are prevalent in the environment ( Ripanda & Miraji, 2022 ; Ripanda, 2024 ), particularly in wastewater ( Ripanda et al., 2023c ; Ripanda et al., 2021 ), and agricultural runoff ( Hossein et al., 2023 ; Miraji et al., 2021 ; Ripanda et al., 2021 ), exacerbating the spread of resistance genes. The healthcare infrastructure struggles with inconsistent antibiotic stewardship, and diagnostic capacities are often insufficient, leading to the misuse of antibiotics. For example, antibiotics are frequently prescribed without confirming bacterial infections, driven by limited access to diagnostic tools ( Doern & Brecher, 2011 ). Additionally, counterfeit and substandard medications ( Al-Worafi, 2020 ; Kelesidis et al., 2007 ), further contribute to resistance.

Future efforts must focus on strengthening regulatory frameworks, improving antibiotic stewardship, and enhancing public education on the prudent use of antibiotics. The implementation of robust surveillance systems is critical to monitor AMR patterns and guide targeted interventions. Moreover, integrating AMR strategies into the broader public health agenda, including water, sanitation, and hygiene (WASH) initiatives, is vital for controlling the spread of resistance. Collaboration between government, healthcare providers, and international organizations will be essential to build capacity and ensure sustainable solutions to the growing AMR challenge in Tanzania.

While Tanzania has made commendable strides in addressing AMR, significant research gaps remain that prospective researcher must address to strengthen the country’s AMR response. The limited scope and geographic coverage of AMR surveillance systems, necessitating studies that leverage innovative, cost-effective technologies such as genomic sequencing or AI-driven analytics to monitor resistance patterns in underrepresented regions. Additionally, the long-term ecological and human health impacts of antimicrobial pollutants in Tanzanian waterways and agricultural soils are poorly understood, highlighting the need for investigations into how these pollutants contribute to resistance gene proliferation. Research into the effectiveness of specific water, sanitation, and hygiene (WASH) interventions in mitigating AMR transmission dynamics is also essential. Furthermore, there is a pressing need to explore the cultural, economic, and behavioral drivers of antibiotic misuse, particularly in rural and underserved areas, to inform targeted public health campaigns. Alternative antimicrobial strategies, such as plant-based treatments or phage therapy, require further study to reduce reliance on conventional antimicrobials including antibiotics. Finally, while regulatory frameworks exist, their implementation and efficacy remain underexplored, creating opportunities for research into enforcement mechanisms and their outcomes. Addressing these gaps will provide critical insights to guide sustainable, evidence-based strategies in the fight against AMR in Tanzania.

Antimicrobial pollution in Tanzania poses an escalating threat at the nexus of public health, agriculture, and environmental sustainability. High levels of antimicrobial residues and resistant bacteria, particularly E. coli and Klebsiella spp. have been detected indicating contamination from human and animal waste streams. Unregulated antibiotic use continues to drive the emergence of multidrug-resistant pathogens, with residues often exceeding recommended limits in animal products and sediments. While One Health commitment and national action plan mark substantial progress in Tanzania, addressing AMR pollution demands enhanced environmental monitoring, strict enforcement of antimicrobial stewardship, and community-level awareness. Leveraging digital technologies, local research innovations, and community education can transform current efforts into data-driven, sustainable solutions. The stakes are high, but with strategic investments and a concerted national effort, Tanzania can mitigate the impact of AMR, safeguarding the health and well-being of its population for generations to come.