Zoonoses and Public Health最新文献

Background: Between 1999 and 2021, 505 culture-confirmed cases of M. bovis disease in humans (zoonotic tuberculosis, TB) were diagnosed in England. We aimed to estimate the prevalence of M. bovis infection in persons exposed to TB-infected cattle in England and identify any risk factors associated with latent TB infection (LTBI) in this population.

Methods: We co-developed a retrospective cohort study in Southwest England, a bovine TB high risk area, with members of the UK farming community. A questionnaire captured participant characteristics, behaviours and farming practices. Linkage with historical herd testing data was used to categorise participants as low, medium or high risk for TB exposure. Interferon gamma release assay (IGRA) positivity with Quantiferon was used to determine LTBI status and linked to questionnaire data.

Results: We recruited 90 participants at agricultural shows and a standalone event. Participants were farmers/farm workers (76/90) and veterinary professionals (10/90). Median age was 45.5 years (IQR: 19-77); 63% were male; 67% reported BCG vaccination. M. bovis exposure was via direct contact with infected cattle and consumption of raw milk. One participant in the high-risk group was IGRA positive, all other participants were IGRA negative. Estimated IGRA positivity rate was 1.1% (95% CI 0.058%-7.0%) in all participants and 4.0% (95% CI 0.21%-22%) in participants with high exposure levels.

Conclusions: We found limited LTBI in individuals in contact with TB-infected cattle in England, despite high and prolonged exposure. We identified a high-risk group of farmers who should be prioritised for future engagement.

Introduction: Reducing the prevalence of Shiga toxin-producing Escherichia coli (STEC) is an important responsibility of provincial abattoirs to ensure safe products are entering the human food chain. Currently, within Ontario, provincial abattoirs are mandated to apply various antimicrobial treatments to cattle carcasses to help decrease pathogen presence post-slaughter. The objectives of this study were to determine the prevalence of contamination of O157 and non-O157 STEC in carcasses from Ontario provincial abattoirs.

Methods: Using mixed logistic regression models, we examined the associations between cattle characteristics, season, monitoring program and abattoir interventions on carcass contamination with E. coli O157:H7, non-O157:H7 STEC and the top six non-O157:H7 STEC of concern to public health (i.e., O26, O45, O103, O111, O121 and O145). Random effects for abattoir and the area in which an abattoir was located were included in these models to adjust for clustering at these levels. The STEC examined was detected through two provincial molecular-based monitoring programs.

Results: Samples taken in the summer had significantly greater odds of screening positive for the top six STEC compared to samples taken in the fall and winter months. Similar seasonal effects were observed for E. coli O157:H7, but for only one of the monitoring programs (i.e., seasonal effects were modified by a monitoring program). Carcasses that received dry age treatment had significantly lower odds of screening positive for STEC. Samples collected from veal calf and cow carcasses had significantly greater odds of screening positive for STEC than samples taken from the carcasses of steers or heifers, but not bulls. Most of the variance in carcass contamination was explained at the carcass level.

Conclusions: These results suggest that additional efforts in risk mitigation should focus on cattle of certain demographic characteristics and higher risk seasons and that additional carcass-level interventions be explored.

Background: Tick-borne encephalitis virus (TBEV) is one of the most significant zoonotic diseases in Europe. It primarily spreads through the bites of infected ticks and, less frequently, through consumption of raw milk and dairy products from viremic domestic ruminants.

Aims: Assess the prevalence of TBEV or anti-TBEV antibodies in milk and milk products from domestic ruminants in Europe.

Materials and methods: Systematic literature review adhering to the JBI methodology, and reported following the PRISMA framework.

Results: From the 16 included scientific articles, we extracted 35 data collections (31 on raw milk and 4 on raw milk cheese); studies focused on cow (n = 15), goat (n = 11) and sheep milk (n = 5), goat (n = 3) and cow/goat cheese (n = 1). Fifteen data collections involved individual milk and 16 bulk milk samples. The estimated prevalence of TBEV in individual raw milk and cheese was 6% and 3%, respectively. TBEV prevalence in bulk milk was very heterogeneous, with most values either 0% or 100%.

Discussion: Although published research on TBEV transmission to humans through milk and dairy products in the EU countries is limited, our results highlight the potential infection risk for consumers. The variable prevalence reported in the studies may reflect the focal nature of TBEV.

Conclusion: Studies on unpasteurised dairy products from domestic ruminants can be valuable for the detection of TBEV presence in a geographic area, even when human cases are not reported. Thanks to the ease of sample collection, their testing could be adopted in monitoring plans on TBEV.

Introduction: The mosquito-transmitted Usutu virus has spread in the last few years, becoming endemic in several areas of Europe, such as in the southern French region of the Camargue. Our aim was to study the relationships between the presence of the viral agent in Culex mosquitoes and the structure of bird communities in the context of the dilution effect.

Methods: We carried out mosquito and bird censuses in several selected localities across a land-use gradient and screened mosquito pools for flaviviruses. We focused on exploring how host bird diversity, richness, abundance and evenness were associated with Usutu detection in Cx. pipiens.

Results: Usutu virus was detected in seven pools of Cx. pipiens, and phylogenetic analysis identified Usutu lineage Africa 3, confirming its circulation. The probability of detection in mosquitoes is associated with areas with lower bird evenness and diversity but higher bird abundance and richness and higher Cx. pipiens abundances.

Conclusions: Bird evenness was the variable with the greatest explanatory power, being negatively related to the probability of detecting Usutu in Cx. pipiens, supporting a dilution effect. These results will help us better understand the relationships between bird community structure and the risk of Usutu mosquito-borne disease.

Introduction: Drastic changes in meteorological variables due to climate change will likely have an implication on the proliferation of vectors such as mosquitoes. Extreme weather events may therefore promote the emergence/re-emergence of mosquito-borne diseases (MBDs) and potentiate the risk of endemicity, particularly, in small island nations.

Method: A systematic review was chosen to methodically ascertain the knowledge gaps that exist in determining the influence of the changing climate on MBDs in small islands with vulnerable public health systems. This review was conducted using the PRISMA guidelines.

Results: Following extraction of 600 articles from the databases, 16 studies were determined to meet the selection criteria. The majority of these research papers were from Sri Lanka (n = 9) while the remaining articles were distributed between islands in the Pacific and Atlantic Ocean. Several of these studies used regression modelling techniques to discuss the effect of multiple meteorological variables on the incidence of MBDs. A positive relationship was observed between temperature and the relative risk of MBDs in 72% of the papers. Rainfall enhanced dengue transmission in 84% of the studies included. All the articles discussing the effect of humidity illustrated a similar trend while wind speed was the only climatic variable demonstrating a negative relationship with MBDs.

Discussion: Considering the intricate nature of the non-linear exposure-response link is crucial when estimating the lagged effect of the changing climate on MBDs transmission. Other challenges associated with bias and confounders in the selected studies as well as meteorological data accessibility, were highlighted. Therefore, it was not possible to conclusively establish that the changing climatic variables do influence the spread of MBDs which accentuated the need for conducting further studies to illustrate the effect of changing weather variables on the incidence of MBDs, with an emphasis on vulnerable small island nations.

Introduction: Nonhuman primates (NHPs) can transmit zoonotic diseases to humans because of their close genetic relationship, facilitating the cross-species transmission of certain pathogens. In Thailand, Macaca is the most common NHP genus and their inhabits area are in close proximity of human, particularly in urban and suburban areas, where frequent interactions with humans increase the risk of pathogen transmission. The risk is influenced by factors such as the type of pathogen, the mode of transmission (e.g. direct contact or vector-borne), and the density of human and macaque populations in the regions. This study aims to investigate potential zoonotic infections in free-ranging macaques residing in human-monkey conflict areas.

Methods: From 2014 to 2023, 2703 macaques across 29 provinces in Thailand were tested for 18 pathogens using PCR, RT-PCR, or real-time PCR. The associations between disease occurrence, demographic variables, and sample types of macaques were analysed using univariable and multivariable regression.

Results: The overall pathogen infection percentage was 35.7% (965/2703). Simian foamy virus (SFV) had the highest infection percentage at 52.5% (759/1446), followed by Herpesviridae at 41.4% (353/852), Plasmodium spp. at 1.8% (14/758), and hepatitis B virus at 0.1% (2/1403). Significant differences were observed among different sampling sites, macaque age groups, and species in infection proportion of SFV, and Herpesviridae.

Conclusions: Identifying the pathogens carried by macaques is crucial for preparing for potential disease epidemics and outbreaks.

Introduction: Capnocytophaga is a genus of bacteria that are commensal to the oral microbiome of humans and some animals. Some Capnocytophaga species are found in the human oral cavity and rarely cause disease in people; the species found in animals are zoönotic and can be transmitted to people via saliva. This study describes the clinical and epidemiologic features of patients from whom Capnocytophaga spp. were isolated from blood and other clinical specimens at the California state Microbial Diseases Laboratory.

Methods: Clinical information was obtained from laboratory submission forms and any accompanying medical records and/or from matching records in statewide hospital discharge and emergency department databases.

Results: During the 17-year study period (2005-2021), Capnocytophaga spp. were isolated in 48 specimens from 47 patients. Capnocytophaga canimorsus, which is a zoönotic species, represented 85% of the Capnocytophaga spp. identified to the species level. The median age was 67 years (range: 30-88 years) for the 42 patients infected with a zoönotic species of Capnocytophaga and 36 years (range: 12-65 years) for the four patients infected with a non-zoönotic species. Twenty-five (60%) patients with zoönotic species infections were male, compared to two (50%) patients with non-zoönotic species infections. Capnocytophaga spp. were most frequently isolated from blood (88%), and the most common case presentation was sepsis (45%). A dog or cat bite prior to diagnosis was reported for 14% of patients infected with a zoönotic species of Capnocytophaga. Records for 45% of patients indicated at least one pre-existing health condition associated with depressed immune function.

Conclusions: This study documented that Capnocytophaga spp. can cause rare, severe, invasive disease in mostly older or immunocompromised persons, often without documentation of a dog or cat bite. Providers are encouraged to consider Capnocytophaga spp. infection in immunocompromised pet owners presenting with sepsis, even in the absence of a known animal bite.

Introduction: Japanese Encephalitis (JE) is a life-threatening disease, especially in the Indian subcontinent. Knowledge about the nature and ecology of the dispersal of JE virus (JEV) vectors needs to be increased. This study mechanistically explores the ecology of JEV vectors and the mode and frequency of occurrence of Acute Encephalitis Syndrome (AES) and JEV infections.

Methods: We established a linear relationship between environmental variables and JEV infection by JEV vectors (mosquitoes)-Culex tritaeniorhynchus, Culex vishnui, and Culex pseudovishnui. The relative abundance of three mosquito species was evaluated, and the JE Sample Positivity Rate (SPR) and JE Case Fatality Rate (CFR) were computed.

Results: Culex vishnui had a high abundance in residential areas during the transition from hot-dry (77.34%) to hot-wet period (78.66%) at temperatures between 31°C and 34°C and relative humidity of 80%-85.3%; this period also coincided with occurrence of AES (39 cases in hot-dry and 88 cases in hot-wet period) and JE (8 instances in hot-dry and 31 cases in hot-wet period). JE infection dominated near rainfed rice fields (rainfall: R = 0.67 at p < 0.05; rainy days: R = 0.74, p < 0.01). SPR was up to 32.28%, and CFR was as high as 42.86%; JEV infection was concentrated in adult male humans near rice fields (15.66%).

Conclusions: Climate modulation over the years can influence the distribution of Culex vishnui and, hence, AES and JE cases. JEV infections tend to rise in JE hotspot regions, especially near rice fields. Thus, comprehensive epidemiological investigations will help prevent a silent outbreak of JE.

Introduction: Humans acquire tick-borne pathogens (TBPs) from infected ticks contacted during outdoor activities. Outdoor activity is at its highest in urban green spaces, where the presence of tick populations has increasingly been observed. Consequently, more insight into factors influencing the presence of ticks therein is needed. Here, we assess the occurrence of ticks and several TBPs in urban green spaces in Finland, estimate related human hazard and assess how landscape features influence tick and TBP occurrence therein.

Methods: Ticks collected from five cities during 2019-2020 were utilised. Borrelia, Rickettsia, Neoehrlichia mikurensis, Anaplasma phagocytophilum, Babesia and TBEV were screened from ticks using qPCR. Various landscape features were calculated and utilised in generalised linear mixed models to assess their contribution towards tick and TBP occurrence in green spaces. Finally, human population density proximate to each study site was calculated and used to create population-weighted risk indices.

Results: Borrelia were the most common pathogens detected, with 22% of nymphs and 43% of adults infected. Increasing forest cover had a positive effect on the densities of nymphs and adults, whereas forest size had a negative effect. Middling percentages of artificial surfaces predicted higher nymph densities than low or high values. Human population-weighted risk estimates were highly varied, even within cities. A positive correlation was observed between total city population and risk indices.

Conclusions: Ticks and TBPs are commonplace in urban green spaces in Finland. Enzootic cycles for Borrelia and Rickettsia appear to be well maintained within cities, leading to widespread risk of infection therein. Our results suggest that nymph densities are highest in urban forests of medium size, whereas small or large forests show reduced densities. Green spaces of roughly similar risk can be found in cities of different sizes, emphasising that the identification of areas of particularly high hazard is important for effective mitigation actions.

Background: Leptospirosis is a widespread zoonosis caused by bacteria in the genus Leptospira. Basic epidemiological information is crucial to mitigating disease risk but is lacking for leptospirosis; notably, the hosts responsible for maintaining Leptospira remain largely unknown. Frequently observed near human habitations, hedgehogs (Erinaceus europaeus) are taken to wildlife rescue centres when found sick or injured. Thus, they may pose a risk to human and animal health if they carry pathogenic Leptospira.

Aims: This study aimed to describe Leptospira carriage in a hedgehog population and the potential clinical impacts of the infection.

Material and method: We investigated Leptospira carriage frequency and diversity in urine samples from 69 hedgehogs at a wildlife rescue centre, between April and June 2022. We used quantitative PCR, typing of the 16S rRNA and lfb1 genes, variable number tandem repeat and multispacer sequence typing to characterise Leptospira DNA. An analysis of urinary biochemical parameters was conducted to assess renal function.

Results: We detected Leptospira DNA in 25 (35%) of the urine samples, of which 21 were successfully typed. The latter analysis revealed a limited degree of genetic diversity. L. interrogans (n = 19) predominated, and the only genotype detected was related to the Australis serogroup (n = 17). We also noted the presence of L. borgpetersenii (n = 1) and L. kirschneri (n = 1). There was no relationship between infection status and urinalysis parameters.

Conclusion: These results suggest hedgehogs may act as long-term shedders of Leptospira in natural ecosystems.