Search Results (55)

Rift Valley fever (RVF) is a climate-sensitive mosquito-borne zoonosis long regarded as a rural, pastoral disease, yet accelerating tropical urbanization and intensifying climate variability may be reshaping its epidemiology at the urban–peri-urban interface. This narrative review examines how global climate change and urban-specific climatic conditions jointly shape RVF virus (RVFV) vector habitats, transmission, and burden in tropical and subtropical cities, synthesizing 51 of 412 English-language records identified by a structured, non-systematic search of PubMed, Scopus, Web of Science, and Google Scholar (2009–2026) and selected for relevance to urban and peri-urban RVF. This research draws on human, livestock, and vector evidence from Sub-Saharan Africa, the Arabian Peninsula, and Indian Ocean islands across epidemic and inter-epidemic periods. The synthesis indicates that impervious surfaces, poor drainage, and open water storage can recreate the water-retaining function of rural dambos, sustaining a year-round larval habitat, and that Culex quinquefasciatus dominance together with peri-urban cattle may form an amplification bridge to humans. Direct evidence remains scarce, anchored by a single peri-urban serosurvey and limited urban slaughterhouse entomology. Critical gaps include urban primary-vector ecology, infection-rate data, urban-heat effects, city-specific exposure studies, and coupled climate–urban burden models. We conclude that RVF is a plausible emerging urban threat warranting proactive inter-epidemic surveillance and integration of RVF into urban planning and One Health systems. Full article

Cystic echinococcosis (CE), caused by Echinococcus granulosus sensu lato (s.l.), is a significant zoonotic disease affecting livestock and public health worldwide, particularly in endemic regions such as La Araucanía, Chile. This study evaluated the role of cattle in the transmission dynamics of E. granulosus sensu stricto (s.s.) by morphologically and molecular characterizing hydatid cysts (HC) collected from cattle, sheep, pigs, and goats. A total of 123 cysts were obtained from a local slaughterhouse, with cattle contributing the majority of samples (n = 94). Fertility was highest in sheep (76.2%) and low in cattle (3.2%), while cysts from pigs and goats were infertile. PCR amplification and sequencing of the cox1 gene confirmed the predominance of genotype G1 (98.1%), with two additional haplotypes (Eg^B and Eg^C) identified in cattle and sheep. Two cattle samples harbored genotype G3. Phylogenetic analyses grouped all sequences within the E. granulosus s.s. complex. The results corroborate the role of cattle as important sentinels for environmental surveillance of CE due to their exposure and traceability but highlight their lower competence in parasite transmission to definitive hosts compared with sheep. The genetic diversity observed aligns with previous findings in Chile, underscoring the epidemiological significance of E. granulosus s.s. and genotype G1 in the region. Full article

(1) Background: Slaughterhouses receive livestock from different sources, enabling the collection of health-related surveillance information. Few surveillance frameworks integrate slaughterhouse distribution with livestock population density for prioritizing surveillance areas. (2) Methods: The surveillance priority of livestock in Thailand was determined on a district basis. Registered slaughterhouses were mapped using kernel density estimation. Livestock were mapped using census data. The z-scores were combined to determine the composite surveillance prioritization index for each district. The 90th percentile was used to determine district-level surveillance priority. Spatial analyses using Global Moran’s I and LISA statistics were performed. Sensitivity analyses assessed robustness. (3) Results: The composite district-level priority index ranged from −0.728 to 9.071 (I = 0.642, p < 0.001). LISA identified 120 High–High (HH) priority districts. Of these, 42 priority districts were selected, concentrated in the northeastern and west-central regions. (4) Conclusions: This model is replicable and can be applied to other regions that rear livestock and use slaughterhouses for surveillance. Full article

This retrospective study evaluated the prevalence and economic impact of tuberculosis-likelesions (TB) in cattle, sheep, and goats slaughtered at municipal abattoirs in the provinces of Bejaia and Jijel between 2019 and 2024, and examined their ecological association with reported human tuberculosis (TB) cases. The overall prevalence of tuberculosis-like lesions in carcasses, lungs, and livers was 0.08%, 0.85%, and 0.19%, respectively, with cattle showing the highest lesionprevalence. Logistic regression analysis identified species, season, geographic location, and climatic factors as significant predictors of lesion occurrence. Analysis of human tuberculosis records revealed a strong ecological positive correlation (r = 0.81, p < 0.05) between bovine pulmonary tuberculosis-like lesions and extra-pulmonary tuberculosis in humans. Over the six-year period, large quantities of condemned carcasses and organs resulted in direct losses of €3.23 million, while reduced carcass weight accounted for indirect losses of almost €11 million.Ruminant tuberculosis-like lesions caused substantial economic losses, totaling €14.16 million over six years, with cattle accounting for 99.8% of the impact. Projected losses could reach €16.7 million by 2030 under comparable surveillance market and control conditions, highlighting the potential ongoing financial burden of the disease. Tuberculosis-like lesions remain relevant in northern Algeria, posing important veterinary, zoonotic, and economic concerns. Enhanced surveillance, laboratory confirmation of suspected lesions, and the strict implementation of control measuresare essential to limit disease transmission and mitigate its impact. Full article

This five-month epidemiological investigation evaluated pre-slaughter welfare, carcass-processing practices, and post-mortem lesion prevalence in 1012 cattle and 413 pigs slaughtered in Enugu State, Nigeria. Direct observations and post-mortem inspections were conducted following OIE standards. Animal welfare was markedly compromised. Cattle were dragged from the lairage to kill floor, restrained in lateral recumbency for over 30 min before bleeding, and slaughtered without stunning. Pigs were transported tied to motorcycles and processed on unsanitary floors. The lairages lacked roofing, clean water, and adequate drainage. Carcass handling was unhygienic, with meat processed near maggot-infested drains and transported in open vans or motorized tricycles used to commute passengers and cement. Of all cattle examined, 45.3% (458/1012) exhibited gross lesions attributable to contagious bovine pleuropneumonia (CBPP, 15.5%), fasciolosis (18%), liver abscessation (6.6%), ascariasis (4.6%), and bovine tuberculosis (0.5%). No lesions were detected in pigs. Lesion occurrence differed significantly (p < 0.05) by sex (males = 44.1%, females = 66.7%), age (<4 years = 54.1%, ≥4 years = 45.4%), breed (White Fulani = 45.5%, others = 36.7%), slaughterhouse location, and season (rainy = 45.2%, dry = 45.5%). Temporal analysis showed the highest lesion rate in April (68.3%), declining to 37.7% in May. Lesions of CBPP and fasciolosis were significantly more frequent in young cattle and during the rainy months (p < 0.05). These findings reveal systemic welfare violations and disease endemicity within the municipal abattoirs surveyed. The combination of poor pre-slaughter welfare, unhygienic meat handling, and high prevalence of zoonotic and economically important livestock disease lesions highlights urgent public health concerns. Strengthening abattoir infrastructure, enforcing pre-slaughter animal welfare and hygiene regulations, mechanizing slaughter processes, and instituting continuous surveillance within the One Health framework are essential for ensuring meat safety and public health security in Nigeria and beyond. Full article

Methicillin-resistant Staphylococcus aureus (MRSA) is a major antimicrobial-resistant pathogen affecting both human and animal health. Although historically associated with healthcare settings, MRSA is now established in livestock production and throughout the production chain. Its detection in animals, food products, and processing environments reflects the complex ecology of antimicrobial resistance (AMR) in modern food systems. This narrative review synthesizes current evidence on the molecular basis of methicillin resistance and multidrug resistance determinants, as well as the epidemiology of MRSA in food-associated settings. Particular emphasis is placed on its occurrence in animal-derived foods and key reservoirs within farms, slaughterhouses, and processing environments. Livestock-associated populations are dominated by clonal complex CC398. In contrast, CC9 is prevalent in pig production systems in Asia, while CC5-related lineages occur at the human and animal interface. MRSA has been detected in retail meat and animal-derived foods at low but measurable prevalence, indicating contamination during slaughter and processing. Virulence determinants include staphylococcal enterotoxins linked to food poisoning and Panton–Valentine leukocidin associated with severe infections. Biofilm formation and adhesins further support persistence and colonization. Epidemiological and molecular evidence indicates that livestock, processing environments, and food-contact surfaces act as interconnected reservoirs sustaining MRSA circulation. Human exposure occurs primarily through occupational contact and environmental pathways, whereas foodborne transmission appears less common. Effective control requires integrated surveillance, responsible antimicrobial use in livestock production, and strict hygiene practices throughout the production chain within a One Health framework. Full article

Slaughterhouse detection of lesions compatible with bovine tuberculosis represents a key passive surveillance component in Santa Catarina, Brazil, yet subsequent trace-back investigations often fail to identify infected farms. This study developed a quantitative framework to prioritize epidemiological investigations by estimating the probability of infection associated with each farm connected to PCR-confirmed cases. Using official movement records and historical diagnostic data, we reconstructed the lifetime contact networks of slaughtered cattle presenting confirmed Mycobacterium bovis lesions (n = 502). For each sentinel animal–farm interaction (n = 1452), infection probability was estimated through a non-homogeneous Poisson process incorporating exposure duration and the time-weighted average herd size as determinants of infectious pressure. After evaluating stochastic variability through Monte Carlo simulation, a deterministic model using the mean infectious-pressure parameter was applied to classify farms into high-, medium-, and low-risk categories. Model performance was assessed using validated field diagnostic outcomes within a three-year temporal window. High-risk farms represented most validated contacts (58%) and demonstrated a relative risk of 3.48 compared with lower-risk category. These findings indicate that a standardized risk-based classification can substantially improve the prioritization of trace-back investigations, offering a practical decision-support tool to enhance bovine tuberculosis surveillance and contribute to eradication strategies in Santa Catarina. Full article

Background: Hepatitis E virus (HEV) is an increasingly recognized cause of acute viral hepatitis in Thailand as the burden of hepatitis A, B, and C has declined. HEV is a positive-sense RNA virus in the family Hepeviridae with three major open reading frames encoding replication proteins (ORF1), the capsid protein (ORF2), and an accessory protein involved in viral egress (ORF3). Unlike highly endemic regions where genotypes 1 and 2 are linked to waterborne outbreaks, infections in Thailand are reported mainly as sporadic cases associated with zoonotic transmission, most commonly genotype 3. Objectives: This review summarizes the epidemiology, transmission routes, and public health implications of HEV infection in Thailand. Methods: Peer-reviewed studies on HEV seroprevalence, molecular epidemiology, and transmission in Thailand were identified through PubMed using combinations of the keywords “HEV” and “Thailand”. Two investigators independently screened titles, abstracts, and full texts. Eligible studies were synthesized qualitatively. Results: Earlier studies suggested low population exposure, but more recent evidence indicates substantial cumulative risk. A nationwide survey among blood donors reported anti-HEV IgG seroprevalence of about 30%, with geographic variation and increasing prevalence with age. Detection of HEV RNA in pigs, slaughterhouse environments, and retail pork products, together with links to raw or undercooked pork consumption, supports pigs as the principal reservoir and foodborne exposure as an important route. Transfusion-associated infection has also been documented. Conclusions: In Thailand, HEV infection is linked mainly to zoonotic and foodborne transmission involving genotype 3. Stronger surveillance, food safety measures, and risk-based blood safety policies are needed. Full article

In order to investigate the prevalence of duck Tembusu virus (DTMUV) in several regions of China, this study conducted an epidemiological survey on 2674 avian throat swab samples (including chickens, ducks, geese, and pigeons) collected from seven provincial-level administrative regions in China in 2024. Following RT-qPCR testing, 198 positive samples were identified, demonstrating an overall positivity rate of 7.40% (198/2674) across the seven provinces included in the study. Subsequent virus isolation using BHK-21 cells led to successful isolation in 17 cases. Additionally, genetic evolution analysis of the partial NS5 gene was carried out on these 17 isolates through RT-PCR amplification and sequencing. The data analysis indicated that Guangdong Province had the highest positive detection rate, reaching 22.40% (86/384), followed by Henan at 12.24% (47/384). Among infected hosts, geese were primarily affected by DTMUV, with a positivity rate of 40.76% (97/238). The prevailing subgroup of DTMUV in circulation in China is subgroup 3.2. Farmer’s markets, wholesale markets, slaughterhouses, and poultry farms all showed evidence of DTMUV presence, indicating widespread contamination across diverse locations. This study examines the distribution, genetics, and phylogenetic features of DTMUV in China, which will enhance our comprehension of the epidemiological landscape of DTMUV in China. Full article

Porcine circovirus 3 (PCV3), first reported in 2016, is associated with diverse clinical conditions, including porcine dermatitis and nephropathy syndrome, reproductive disorders, and systemic inflammation, and affects pigs of all ages. To investigate the prevalence and genetic evolution of PCV3 in Hunan Province, China, 700 lymph node tissue specimens were collected from slaughterhouses and hazard-free disposal centers across 14 prefecture-level cities between 2021 and 2024 and screened using real-time quantitative PCR (qPCR). Epidemiological investigation revealed an overall PCV3 positivity rate of 29.4% (206/700) in the province. The highest prevalence was observed in Yiyang City (56%, 28/50), whereas no positive samples were detected in Zhuzhou City (0/30). Among the positive samples, 34 specimens from different cities with Ct values < 25 were selected for Cap gene amplification and sequencing. Phylogenetic analysis showed that PCV3c was the predominant genotype (67.6%, 23/34), followed by PCV3a (32.4%, 11/34), while PCV3b was not detected. We identified twelve amino acid substitution sites within Cap proteins. Furthermore, B-cell linear epitope prediction and homology modeling of the Cap protein identified seven linear epitopes, with ten amino acid variation sites located within these epitopic regions. This study enriches the molecular epidemiological data of PCV3 in southern China and provides a reference for future PCV3 control strategies. Full article

Slaughterhouses serve as critical surveillance hubs for identifying subclinical and economically important diseases in food-producing animals. Trueperella (Arcanobacterium) pyogenes, an opportunistic pathogen commonly found on the mucous membranes of livestock, is associated with mastitis, abortion, and suppurative infections such as abscesses. In this study, we investigated 30 pig carcasses fully condemned due to vertebral osteomyelitis (VO) at two slaughterhouses in Gwangju, Republic of Korea, between November 2023 and May 2024. From abscess lesions, 11 T. pyogenes strains were isolated and characterized morphologically, biochemically, and genetically. The hemolytic exotoxin pyolysin (plo gene), a major virulence factor, was detected in five isolates (45.46%). Phylogenetic analysis of partial 16S rDNA sequences confirmed close clustering with known T. pyogenes reference strains. All 11 isolates exhibited multidrug resistance, showing resistance to 8–14 antimicrobial agents per strain. Complete resistance (11/11, 100%) was observed against amikacin (AMI), nalidixic acid (NAL), chloramphenicol (CHL), florfenicol (FFN), and trimethoprim/sulfamethoxazole (SXT). High resistance rates were also detected for erythromycin (ERY) and clindamycin (CLI) (10/11, 90.9%), ceftazidime (TAZ), ceftriaxone (AXO), ciprofloxacin (CIP) (7/11, 63.6%), and tetracycline (TET) and streptomycin (STR) (5/11, 45.5%), while gentamicin (GEN) resistance was found in three isolates (27.3%). In contrast, none of the isolates showed resistance to ampicillin, cefoxitin, or cefotaxime. These findings underscore the epidemiological value of abattoir-based monitoring in detecting emerging pathogens and tracking antimicrobial resistance. The results provide important baseline data to inform disease control strategies, guide antimicrobial stewardship, and support One Health approaches, including the development of preventive measures such as vaccines. Full article

Y. enterocolitica is a cold-tolerant, foodborne pathogen that poses a significant risk to public health, with pigs identified as its main reservoir. This review explores the current knowledge on the epidemiology, transmission, and virulence of Y. enterocolitica in pigs, highlighting their central role in spreading the bacterium to humans—primarily through the consumption of raw or undercooked pork. The pathogen is frequently found in pig tonsils and intestines and can contaminate meat during slaughter. Among the various strains, bioserotype 4/O:3 is the most common cause of human illness. Y. enterocolitica carries a diverse set of virulence genes, such as ail, yst, inv, and yad, and evades immune responses. The review also covers major outbreaks, risk factors on farms and in slaughterhouses, and the limitations of current surveillance systems. Reducing the impact of Y. enterocolitica requires a One Health approach linking animal health, food safety, and public health. Full article

Because of the relevance of Salmonella spp. in poultry, in 2016, the Brazilian Ministry of Agriculture, Livestock, and Supply updated its regulation for the control and monitoring of Salmonella in the poultry meat production chain. We herein present the results of the official monitoring of sampling cycles of carcasses performed by the Brazilian official veterinary inspection service (SIF) and the Center for Epidemiology, Statistics, and Public Health of the Veterinary School of the Federal University of Minas Gerais. Samples were collected in March–September 2017, during which 140 slaughterhouses slaughtered over three billion chickens. The establishments were classified according to the number of animals slaughtered per day, and cycles varied according to the size of the establishment. Sample weights were defined to increase the external validity of the data. Chicken carcasses were randomly sampled after chilling and dripping. A total of 1434 samples were analyzed in official laboratories using Vidas SLM and SPT systems, for positive samples were used the ISO 6579:2014. The estimated prevalence of Salmonella spp. in chicken carcasses was 17.88% (95% CI 14.34–22.05). Considering the representativeness of Brazilian chicken meat in the global market, constant evaluation and review of the program is necessary to reduce the prevalence of Salmonella. Full article

Viral hepatitis E represents an important global health problem caused by the hepatitis E virus (HEV). Cases of HEV infection are increasingly associated with food-borne transmissions after the consumption of raw or undercooked food products from infected animals in high-income regions. Although most cases of infection are asymptomatic, severe courses of infection have been reported in specific groups of people, predominantly among pregnant women and immunocompromised patients. The viral nucleic acid of HEV is increasingly being reported in food-producing animals and different products of an animal origin. Even though the incubation period for HEV infection is long, several direct epidemiological links between human cases and the consumption of HEV-contaminated meat and meat products have been described. In this article, we review the current knowledge on human HEV infections, HEV in different food-producing animals and products of an animal origin, as well as the accumulation and resistance to HEV in farm and slaughterhouse environments. We also provide preventive measures to help eliminate HEV from animals, the human population, and the environment. Full article

Nontuberculous mycobacteria (NTM) are environmental organisms that can cause opportunistic infections in humans and animals. Mycobacterium abscessus (Mab) is a rapidly growing Mycobacterium known for its resistance to multiple antibiotics and ability to cause respiratory, skin, and mucosal infections. Understanding the distribution and prevalence of NTM, particularly Mab, in cattle farms and slaughterhouses is crucial for developing effective prevention and control measures. We collected environmental swabs from various surfaces (e.g., feed troughs, sinks, walls, floors, feces, and padding) in cattle farms and slaughterhouses across multiple provinces. High-throughput sequencing technology was utilized to analyze the 16S rDNA V3–V4 region of bacterial DNA extracted from the samples, and qPCR methods were employed to detect and quantify Mycobacterium abscessus in the collected samples. Bioinformatics analysis was performed to identify and classify the NTM species present in the samples. This study compared the abundance and diversity of NTM in different environments and assessed the potential zoonotic risk. A total of 1648 environmental swabs were collected from cattle farms and slaughterhouses in 12 provinces of China in 2023, of which 12 samples tested positive for Mab qPCR detection, yielding a detection rate of 0.73% (12/1648). Among them, the detection rate of environmental samples from cattle farms and slaughterhouses was 0.42% (3/720) and 0.87% (9/928), respectively. This study provides valuable information on the epidemiology of NTM in cattle farms and slaughterhouses, contributing to developing effective strategies for preventing and controlling NTM infections. It also enhances our understanding of the zoonotic potential of Mycobacterium abscessus and other NTM species. Full article