Understanding human - bat interactions in NSW, Australia: improving risk communication for prevention of Australian bat lyssavirus

Field testing Australian bat lyssavirus risk communication resources

ISSUE ADDRESSED

Australian bat lyssavirus (ABLV) is a fatal zoonosis, which can be transmitted to humans through scratches or bites from infected bats. Currently, there is a lack of research evaluating risk communication resources about ABLV or the dangers from handling bats. The purpose of this study was to field test resources aimed at educating the public about risks to humans and bats from human-bat interaction, then update these resources based upon feedback to ensure they were relevant and appropriately targeted to the public.

METHODS

Thirteen semi-structured interviews with a purposive sample of participants chosen for maximum variation of age and sex were conducted. Two investigators analysed the data independently using a deductive approach and then came to consensus by discussion.

RESULTS

The main themes were a wide-ranging level of knowledge and opinions about bats, the resources having an effect on people, and messaging in relation to children and pets being particularly important.

CONCLUSION

This study highlighted the complexities of risk communication to a broad audience with varied experience and knowledge about bats, and the importance of evaluation prior to implementation to ensure risk communication is relevant and appealing to the intended audience. SO WHAT?: Field testing of health education material prior to implementation is an effective way to ensure key messages are understood, and is important when communicating about fatal but preventable zoonoses such as ABLV.

Emergence, Tropism, Disease, and Treatment of Australian Bat Lyssavirus Infections in Humans

Australian bat lyssavirus (ABLV) is a negative-sense, single-stranded RNA rhabdovirus capable of causing fatal acute encephalitis in humans with similar pathogenesis to its closest serologic relative, rabies virus (RABV). In this review, we describe emergence and classification of ABLV, its known virology, reservoirs, and hosts, as well as both the pathogenesis and treatment approaches currently employed for presumed infections. ABLV was first identified in New South Wales, Australia in 1996 and emerged in humans months later in Queensland, Australia. Only five known bat reservoirs, all of which fall within the Pteropus and Saccolaimus genera, have been identified to date. Although ABLV antigens have been identified in bats located outside of Australia, the three known human ABLV infections to date have occurred within Australia. As such, there remains a potential for ABLV to expand its presence within and beyond Australia. ABLV infections are currently treated as if they were RABV infections by administering neutralizing antibodies against RABV at the site of the wound and employing the rabies vaccine upon possible exposures. Due to its recent emergence, there is still much left unknown about ABLV, posing concerns with how to safely and effectively address current and future ABLV infections.

Rodent–Human Interface: Behavioral Risk Factors and Leptospirosis in a Province in the Central Region of Thailand

This sequential explanatory mixed-method study consisted of analytical, cross-sectional, and qualitative studies. The research was conducted in the Khao Nor and Khao Kaew areas of the Banphot Pisai districts of Nakhon Sawan Province in 2019. Here, we examined the rodent contact characteristics of villagers in these areas and determined the potential characteristics/risk factors associated with rodents using a semi-structured questionnaire, key informant interview (KII), and focus group discussion (FGD). Results of the quantitative study (N1 = 372) characterized participants that contacted rodents per gender, age, occupation, knowledge, attitude, and practice (KAP), including their cultural contexts, and beliefs. Ninety participants (24.2%) reported contact with rodents, and the reasons for their direct physical rodent contact were hunting (35, 9.4%), killing (41, 11.0%), preparing rodents as food (33, 8.9%), consuming cooked meats (12, 3.2%), feeding food (4, 1.1%), cleaning feces (17, 4.6%), and cleaning carcasses (33, 8.9%). Moreover, logistic regression results showed that males encountering rodents were statistically significant (Adjusted OR = 3.137, 95% CI 1.914–5.139, p < 0.001). Low monthly household income (<THB 15,000 or <USD 450) was also negatively statistically significant with encountering rodents (Adjusted OR = 0.57, 95% CI 0.33–0.99, p = 0.04). Additionally, the villagers had a low level of knowledge toward zoonotic diseases and inappropriate attitudes and practices toward contacting rodents and zoonotic diseases. Thirty-five qualitative study participants (N2) participated in the KIIs and FGDs. Various rodent contact activities were also reported among the qualitative research participants, such as hunting, consumption, and selling them to their friends and neighbors. However, these rodents also destroyed their belongings, crops, and plants. Some participants also reported that rodents accounted for leptospirosis transmission. As a result, communication intervention should be planned to provide appropriate knowledge and attitude to the villagers, especially among those who have close contact with rodents in the understudied area.

What can we learn from over a decade of testing bats in New South Wales to exclude infection with Australian bat lyssaviruses?

Australian Bat lyssaviruses (ABLV) are known to be endemic in bats in New South Wales (NSW), Australia. These viruses pose a public health risk because they cause a fatal disease in humans that is indistinguishable from classical rabies infection. All potentially infectious contact between bats and humans, or between bats and domestic animals, should be investigated to assess the risk of virus transmission by submitting the bat for testing to exclude ABLV infection. The aim of this study was to establish the prevalence of ABLV infection in bats submitted for testing in NSW and to document any trends or changes in submission and bat details. We examined all submissions of samples for ABLV testing received by the NSW Department of Primary Industries Virology Laboratory for the 13-year period between 1 May 2008 and 30 April 2021. Fifty-four (4.9%) ABLV-infected bats were detected, with some clustering of positive results. This is greater than the prevalence estimated from wild-caught bats. All bats should be considered a potential source of ABLV. In particular, flying-foxes with rabies-like clinical signs, and with known or possible human interaction, pose the highest public health risk because they are more likely to return a positive result for ABLV infection. This review of ABLV cases in NSW will help veterinarians to recognise the clinical presentations of ABLV infection in bats and emphasises the importance of adequate rabies vaccination for veterinarians.

Australian Bat Lyssavirus: Analysis of National Bat Surveillance Data from 2010 to 2016

Australian bat lyssavirus (ABLV) was first described in 1996 and has been regularly detected in Australian bats since that time. While the virus does not cause population level impacts in bats and has minimal impacts on domestic animals, it does pose a public health risk. For this reason, bats are monitored for ABLV and a national dataset is collated and maintained by Wildlife Health Australia. The 2010–2016 dataset was analysed using logistic regression and time-series analysis to identify predictors of infection status in bats and the factors associated with human exposure to bats. In common with previous passive surveillance studies, we found that little red flying-foxes (Pteropus scapulatus) are more likely than other species to be infected with ABLV. In the four Australian mainland species of flying-fox, there are seasonal differences in infection risk that may be associated with reproductive cycles, with summer and autumn the seasons of greatest risk. The risk of human contact was also seasonal, with lower risk in winter. In line with other studies, we found that the circumstances in which the bat is encountered, such as exhibiting abnormal behaviour or being grounded, are risk factors for ABLV infection and human contact and should continue be key components of public health messaging. We also found evidence of biased recording of some types of information, which made interpretation of some findings more challenging. Strengthening of “One Health” linkages between public health and animal health services at the operational level could help overcome these biases in future, and greater harmonisation nationally would increase the value of the dataset.

Guidelines for communicating about bats to prevent persecution in the time of COVID-19

While the current COVID-19 pandemic continues to wreak havoc on human health and national economies, conservationists are struggling to prevent misguided persecution of bats, which are misleadingly being blamed for spreading the disease. Although at a global level, such persecution is relatively uncommon, even a few misguided actions have the potential to cause irrevocable damage to already vulnerable species. Here, we draw on the latest findings from psychology, to explain why some conservation messaging may be reinforcing misleading negative associations. We provide guidelines to help ensure that conservation messaging is working to neutralize dangerous and unwarranted negative-associations between bats and disease-risk. We provide recommendations around three key areas of psychological science: (i) debunking misinformation; (ii) counteracting negative associations; and (iii) changing harmful social norms. We argue that only by carefully framing accurate, honest, and duly contextualized information, will we be able to best serve society and present an unbiased perspective of bats. We hope this guidance will help conservation practitioners and researchers to develop effective message framing strategies that minimize zoonotic health risks and support biodiversity and its associated ecosystem services.

Identification of focus areas for Australian Bat Lyssavirus potential exposure prevention in the Metro North Hospital and Health Service region

Australian Bat Lyssavirus (ABLV) is a fatal rabies-like disease spread to humans from bats. All people who report bat bites or scratches in Queensland are considered potentially exposed to ABLV and are followed up and treated to prevent ABLV. Preventing members of the public intentionally interacting with bats will reduce the number of potential exposures to ABLV. In order to target public health messaging, this study examines the epidemiology of potential ABLV exposures in Metro North Hospital and Health Service (HHS), a region of Queensland that encompasses metro and rural areas in the south-east of the state. People who intentionally handled bats during the study period were more likely to be adult (93%), male (60%), scratched (51%) by a megabat (72%) and been potentially exposed while rescuing the bat when it was trapped or injured (72%). The number of potential exposures reported in Queensland has increased since 2013; the same year, a Queensland child died of ABLV. Seasonally, exposures are more common during bat breeding and nursing periods when bats are more active (summer to autumn). Although there were more notifications in a band stretching north from the inner city to northern metro suburbs, notification rates were higher in large rural statistical areas in the north of the HHS. These data will be used to develop geographically targeted ABLV prevention messaging for the general public.

Insights into Australian Bat Lyssavirus in Insectivorous Bats of Western Australia

Australian bat lyssavirus (ABLV) is a known causative agent of neurological disease in bats, humans and horses. It has been isolated from four species of pteropid bats and a single microbat species (Saccolaimus flaviventris). To date, ABLV surveillance has primarily been passive, with active surveillance concentrating on eastern and northern Australian bat populations. As a result, there is scant regional ABLV information for large areas of the country. To better inform the local public health risks associated with human-bat interactions, this study describes the lyssavirus prevalence in microbat communities in the South West Botanical Province of Western Australia. We used targeted real-time PCR assays to detect viral RNA shedding in 839 oral swabs representing 12 species of microbats, which were sampled over two consecutive summers spanning 2016–2018. Additionally, we tested 649 serum samples via Luminex^® assay for reactivity to lyssavirus antigens. Active lyssavirus infection was not detected in any of the samples. Lyssavirus antibodies were detected in 19 individuals across six species, with a crude prevalence of 2.9% (95% CI: 1.8–4.5%) over the two years. In addition, we present the first records of lyssavirus exposure in two Nyctophilus species, and Falsistrellusmackenziei.

Managing the risk of Hendra virus spillover in Australia using ecological approaches: A report on three community juries

BACKGROUND

Hendra virus (HeV) infection is endemic in Australian flying-fox populations. Habitat loss has increased the peri-urban presence of flying-foxes, increasing the risk of contact and therefore viral 'spillovers' into horse and human populations. An equine vaccine is available and horse-husbandry practices that minimize HeV exposure are encouraged, but their adoption is suboptimal. Ecological approaches-such as habitat creation and conservation-could complement vaccination and behavioural strategies by reducing spillover risks, but these are controversial.

METHODS

We convened three community juries (two regional; one metropolitan) to elicit the views of well-informed citizens on the acceptability of adding ecological approaches to current interventions for HeV risk. Thirty-one participants of diverse backgrounds, mixed genders and ages were recruited using random-digit-dialling. Each jury was presented with balanced factual evidence, given time to ask questions of expert presenters and, after deliberation, come to well-reasoned conclusions.

RESULTS

All juries voted unanimously that ecological strategies should be included in HeV risk management strategies but concluded that current interventions-including vaccination and changing horse-husbandry practices-must remain the priority. The key reasons given for adopting ecological approaches were: (i) they address underlying drivers of disease emergence, (ii) the potential to prevent spillover of other bat-borne pathogens, and (iii) there would be broader community benefits. Juries differed regarding the best mechanism to create/conserve flying-fox habitat: participants in regional centres favoured direct government action, whereas the metropolitan jury preferred to place the burden on landholders.

CONCLUSIONS

Informed citizens acknowledge the value of addressing the drivers of bat-borne infectious risks but differ substantially as to the best implementation strategies. Ecological approaches to securing bat habitat could find broad social support in Australia, but disagreement about how best to achieve them indicates the need for negotiation with affected communities to co-develop fair, effective and locally appropriate policies.

Avoiding bites and scratches? Understanding the public health implication of human-bat interactions in Ghana

Zoonotic pathogens cause an estimated 70% of emerging and re-emerging infectious diseases in humans, affecting various aspects of human development on a global scale. The significance of bats as a source of emerging infectious diseases is being progressively appreciated. This study was undertaken post-Ebola virus disease in West Africa and assessed the public health implications of human-bat interactions by exploring the reasons for contact between humans and bats, as well as reported actions taken upon experiencing bat bites or scratches. The paper highlights the nuances of human-bat interactions, stressing zoonotic disease risk awareness as well as the sources of information. The study used questionnaires to solicit information from 788 respondents in five communities with significant bat populations. We show that bat consumption was one of the main reasons for human-bat interactions. More men across the various communities ate bat meat. Only a small number of respondents (4.4%) reported being bitten by a bat, and 6.1% had been scratched by a bat. More than 21% had come into direct contact with bat blood. An even lower number went to the hospital after been bitten or scratched by bats. There was little knowledge on post-exposure management. The most common places human-bat interactions occurred were at home and on farms. Seventy-three per cent of the respondents believed that bats carried diseases, with Ebola virus disease being the most mentioned. Respondents indicated that the way they interacted with bats had not changed, even though they believed bats carried diseases and 46% stated that they had not changed the way they interacted with bats over the last two years. Apart from providing information on avoiding bites and scratches, a more holistic framework is needed to reduce human-bat interactions. The paper recommends a comprehensive and coordinated approach to optimizing an effective response to a potential bat-borne zoonotic disease spillover.

Conservation Values and Risk of Handling Bats: Implications for One Health Communication

Flying-foxes provide critical ecosystem services, but their role as hosts to zoonotic pathogens may undermine conservation support. We surveyed 214 residents of Cairns, Australia, regarding their perceptions about health risks associated with flying-foxes and support for flying-fox conservation. Greater likelihood of handling a flying-fox was associated with lower knowledge about risks, greater conservation support, and environmental organization membership. Respondents less likely to seek medical attention after a minor scratch tended to be younger, unemployed and perceive lower risk. Individuals who support flying-fox conservation should be one group targeted in One Health communication integrating health and conservation messages.

What's the risk? Identifying potential human pathogens within grey-headed flying foxes faeces

Pteropus poliocephalus (grey-headed flying foxes) are recognised vectors for a range of potentially fatal human pathogens. However, to date research has primarily focused on viral disease carriage, overlooking bacterial pathogens, which also represent a significant human disease risk. The current study applied 16S rRNA amplicon sequencing, community analysis and a multi-tiered database OTU picking approach to identify faecal-derived zoonotic bacteria within two colonies of P. poliocephalus from Victoria, Australia. Our data show that sequences associated with Enterobacteriaceae (62.8% ± 24.7%), Pasteurellaceae (19.9% ± 25.7%) and Moraxellaceae (9.4% ± 11.8%) dominate flying fox faeces. Further colony specific differences in bacterial faecal colonisation patterns were also identified. In total, 34 potential pathogens, representing 15 genera, were identified. However, species level definition was only possible for Clostridium perfringens, which likely represents a low infectious risk due to the low proportion observed within the faeces and high infectious dose required for transmission. In contrast, sequences associated with other pathogenic species clusters such as Haemophilus haemolyticus-H. influenzae and Salmonella bongori-S. enterica, were present at high proportions in the faeces, and due to their relatively low infectious doses and modes of transmissions, represent a greater potential human disease risk. These analyses of the microbial community composition of Pteropus poliocephalus have significantly advanced our understanding of the potential bacterial disease risk associated with flying foxes and should direct future epidemiological and quantitative microbial risk assessments to further define the health risks presented by these animals.

Potential exposure to Australian bat lyssavirus is unlikely to prevent future bat handling among adults in South East Queensland

Despite ongoing public health messages about the risks associated with bat contact, the number of potential exposures to Australian bat lyssavirus (ABLV) due to intentional handling by members of the general public in Queensland has remained high. We sought to better understand the reasons for intentional handling among these members of the public who reported their potential exposure to inform future public health messages. We interviewed adults who resided in a defined geographic area in South East Queensland and notified potential exposure to ABLV due to intentional handling of bats by telephone between 1 January 2012 and 31 December 2013. The participation rate was 54%. Adults who reported they had intentionally handled bats in South East Queensland indicated high levels of knowledge and perception of a moderately high risk associated with bats with overall low intentions to handle bats in the future. However, substantial proportions of people would attempt to handle bats again in some circumstances, particularly to protect their children or pets. Fifty-two percent indicated that they would handle a bat if a child was about to pick up or touch a live bat, and 49% would intervene if a pet was interacting with a bat. Future public health communications should recognize the situations in which even people with highrisk perceptions of bats will attempt to handle them. Public health messages currently focus on avoidance of bats in all circumstances and recommend calling in a trained vaccinated handler, but messaging directed at adults for circumstances where children or pets may be potentially exposed should provide safe immediate management options.

Potential Exposures to Australian Bat Lyssavirus Notified in Queensland, Australia, 2009-2014

Background

Australian bat lyssavirus (ABLV) belongs to the genus Lyssavirus which also includes classic rabies virus and the European lyssaviruses. To date, the only three known human ABLV cases, all fatal, have been reported from Queensland, Australia. ABLV is widely distributed in Australian bats, and any bite or scratch from an Australian bat is considered a potential exposure to ABLV.

Methodology/Principal Findings

Potential exposure to ABLV has been a notifiable condition in Queensland since 2005. We analysed notification data for potential exposures occurring between 2009 and 2014. There were 1,515 potential exposures to ABLV notified in Queensland, with an average annual notification rate of 5.6 per 100,000 population per year. The majority of notified individuals (96%) were potentially exposed to ABLV via bats, with a small number of cases potentially exposed via two ABLV infected horses and an ABLV infected human. The most common routes of potential exposure were through bat scratches (47%) or bites (37%), with less common routes being mucous membrane/broken skin exposure to bat saliva/brain tissue (2.2%). Intentional handling of bats by the general public was the major cause of potential exposures (56% of notifications). Examples of these potential exposures included people attempting to rescue bats caught in barbed wire fences/fruit tree netting, or attempting to remove bats from a home. Following potential exposures, 1,399 cases (92%) were recorded as having appropriate post-exposure prophylaxis (PEP) as defined in national guidelines, with the remainder having documentation of refusal or incomplete PEP. Up to a quarter of notifications occurred after two days from the potential exposure, but with some delays being more than three weeks. Of 393 bats available for testing during the reporting period, 20 (5.1%) had ABLV detected, including four species of megabats (all flying foxes) and one species of microbats (yellow-bellied sheathtail bat).

Conclusions/Significance

Public health strategies should address the strong motivation of some members of the public to help injured bats or bats in distress, by emphasising that their action may harm the bat and put themselves at risk of the fatal ABLV infection. Alternative messaging should include seeking advice from professional animal rescue groups, or in the event of human contact, public health units. Further efforts are required to ensure that when potential exposure occurs, timely reporting and appropriate post-exposure prophylaxis occur.

Australian bat lyssavirus (ABLV), closely related to classic rabies virus, is widely distributed in bats in Australia. So far, the only three known human ABLV cases, all fatal, have been reported in Queensland, Australia. Any Australian bat-related injury (bite or scratch), or contact of bat saliva/neural tissue with eyes, mouth, nose, or broken skin of humans, is considered a potential exposure to ABLV. Use of timely, appropriate rabies vaccine and human rabies immunoglobulin is recommended to prevent fatal human ABLV disease. Based on notification data for potential exposures to ABLV in Queensland, we found that intentional handling of bats by the general public was the major cause of bat-related injuries; for example, people reported attempting to rescue bats caught in barbed wire fences or fruit tree netting, or attempting to remove bats from a home. This highlights a need to address the strong motivation of some members of the public to help injured bats or bats in distress and the lack of awareness of the risks of contact with or handling of bats, underscoring the importance of avoidance of bat handling by contacting vaccinated, experienced, and well-equipped professional animal rescue groups to deal with bats. There is a need to improve timeliness of notification to ensure immediate post-exposure management. Queensland Health bat testing results revealed the detection of ABLV in four common species of megabats (all flying foxes) and one species of microbats (yellow-bellied sheathtail bat), further reinforcing the message of avoiding all bat-related injuries. Once a potential exposure to ABLV occurs, immediate cleansing of wound (with soap and water for at least 5 minutes and application of povidone-iodine or alcohol) is required; and appropriate and timely rabies vaccine and human rabies immunoglobulin should be administered.

Disease Risk Perception and Safety Practices: A Survey of Australian Flying Fox Rehabilitators

Interactions with flying foxes pose disease transmission risks to volunteer rehabilitators (carers) who treat injured, ill, and orphaned bats. In particular, Australian bat lyssavirus (ABLV) can be transmitted directly from flying foxes to humans in Australia. Personal protective equipment (PPE) and rabies vaccination can be used to protect against lyssavirus infection. During May and June 2014, active Australian flying fox carers participated in an online survey (SOAR: Survey Of Australian flying fox Rehabilitators) designed to gather demographic data, assess perceptions of disease risk, and explore safety practices. Responses to open-ended questions were analysed thematically. A logistic regression was performed to assess whether rehabilitators’ gender, use of PPE, threat perception, and years of experience predicted variation in their odds of being bitten or scratched. Eligible responses were received from 122 rehabilitators located predominantly on the eastern coast of Australia. Eighty-four percent of respondents were female. Years of experience ranged from <1 to 30 years (median 5 years). Respondents were highly educated. All rehabilitators were vaccinated against rabies and 94% received a rabies titre check at least every two years. Sixty-three percent of carers did not perceive viruses in flying foxes as a potential threat to their health, yet 74% of carers reported using PPE when handling flying foxes. Eighty-three percent of rehabilitators had received a flying fox bite or scratch at some point during their career. Carers provide an important community service by rescuing and rehabilitating flying foxes. While rehabilitators in this study have many excellent safety practices, including a 100% vaccination rate against rabies, there is room for improvement in PPE use. We recommend 1) the establishment of an Australia-wide set of guidelines for safety when caring for bats and 2) that the responsible government agencies in Australia support carers who rescue potentially ABLV-infected bats by offering compensation for PPE.

Wildlife rehabilitators can encounter risks when handling animals, such as physical harm and exposure to infectious diseases. In Australia, rehabilitators that care for fruit bats may be exposed to Australian bat lyssavirus if bitten or scratched, which is fatal to people not vaccinated against rabies. We initiated a survey to assess rehabilitators’ perceptions of disease risk associated with fruit bats as well as rehabilitators’ safety practices. Despite an excellent rabies vaccination rate (100%), we found room for improvement in use of personal protective equipment. Supporting this, our regression analysis showed that use of protective equipment is associated with less chance of being bitten or scratched. Rehabilitators that are able to safely handle fruit bats can reduce risk to themselves, model good behaviour for onlookers, and protect animals from euthanasia. We recommend that carers develop Australia-wide guidelines for safety when rehabilitating bats and that the responsible government agencies in Australia support carers who rescue potentially lyssavirus-infected bats by offering compensation for costly protective equipment.