Understanding Q Fever Risk to Humans in Minnesota Through the Analysis of Spatiotemporal Trends

Transmission modelling of environmentally persistent zoonotic diseases: a systematic review

Transmission of many infectious diseases depends on interactions between humans, animals, and the environment. Incorporating these complex processes in transmission dynamic models can help inform policy and disease control interventions. We identified 20 diseases involving environmentally persistent pathogens (ie, pathogens that survive for more than 48 h in the environment and can cause subsequent human infections), of which indirect transmission can occur from animals to humans via the environment. Using a systematic approach, we critically appraised dynamic transmission models for environmentally persistent zoonotic diseases to quantify traits of models across diseases. 210 transmission modelling studies were identified and most studies considered diseases of domestic animals or high-income settings, or both. We found that less than half of studies validated their models to real-world data, and environmental data on pathogen persistence was rarely incorporated. Model structures varied, with few studies considering the animal-human-environment interface of transmission in the context of a One Health framework. This Review highlights the need for more data-driven modelling of these diseases and a holistic One Health approach to model these pathogens to inform disease prevention and control strategies.

Q fever prevention and vaccination: Australian livestock farmers' knowledge and attitudes to inform a One Health approach

BACKGROUND

Livestock farmers are at risk of Q fever, a zoonotic disease transmitted to humans from animals such as cattle, sheep and goats. Australia bears substantial Q fever burden, particularly among farmers. A One Health approach engages cross-sectoral collaboration among animal, human and environmental health and is the preferred framework for Q fever prevention.

METHODS

Cattle, sheep and goat farmers were invited to participate in an online survey in 2019 to gauge perceptions about Q fever and its prevention. Participants were recruited via membership newsletters and social media. Descriptive analyses and logistic regressions were performed.

RESULTS

A total of 351 farmers completed the survey. Most respondents (80%) had been farming for ≥20 years, with sheep and beef cattle their primary stock. 71% reported knowledge of Q fever, and 85% identified transmission through contaminated dust inhalation was highly likely. The majority of respondents (97%) were aware of Q fever vaccine, and 95% agreed it was effective in preventing disease, yet 42% remained unvaccinated. Reported barriers to vaccination included poor access to a trained doctor and time and cost related to vaccination. Most farmers (≥91%) believed that subsidized vaccination and improved awareness would promote higher uptake.

CONCLUSION

While Q fever knowledge among respondents was good, their practices related to airborne transmission prevention were poor. Livestock farmers would benefit from adherence to dust and aerosol transmission prevention practices. One Health partnership between government and industry is needed to promote Q fever awareness and address low vaccination rates among livestock farmers by funding vaccination programs.

Spatial, temporal, and occupational risks of Q fever infection in South Australia, 2007-2017

BACKGROUND

The burden of Q fever on at risk population groups in Australia is substantial, despite the availability of a vaccine. Our objectives were to: (a) describe the epidemiology of notified Q fever cases in South Australia (SA), (b) identify if Q fever infection is associated with occupational exposure, and (c) detect the possible spatial and temporal association of Q fever with livestock density.

METHODS

Laboratory confirmed Q fever notifications from January 2007 to December 2017 were obtained from the SA Health Department. Q fever notification rates and incidence rate ratios were calculated for gender, notification year, age group, occupation category, and primary exposure suburb. Spatial mapping and analysis of Q fever notifications was undertaken using livestock data, and abattoirs and saleyards located in SA.

RESULTS

During the study period 167 Q fever cases were notified. Males predominated (72%), with higher rates observed in the 21-40year age group (1.52/100,000), and eight cases (5%) reported prior Q fever vaccination. Most frequently listed occupation categories were livestock farmers (35%), and abattoir workers (20%), but in 15% of cases, there was no known occupational risk. Highest notifications (22%) were recorded in the suburb containing an abattoir. The number of goats, cattle and sheep was not associated with Q fever notifications.

CONCLUSIONS

Q fever predominance among males in their twenties and thirties may indicate vaccination under-coverage among the young workforce possibly due to high turnover of workers. Q fever among those vaccinated raises concerns about vaccine efficacy or potential waning immunity. Our findings are consistent with previous studies highlighting abattoir workers as a high-risk occupational group because of its transient workforce, and low vaccination coverage. Q fever notifications in SA may be unrelated with spatial livestock density. Further One Health research involving veterinary, public health and environmental data is required.