Pulmonary adiaspiromycosis in armadillos killed by motor vehicle collisions in Brazil

Fungal primary and opportunistic pathogens: an ecological perspective

Fungal primary pathogenicity on vertebrates is here described as a deliberate strategy where the host plays a role in increasing the species' fitness. Opportunism is defined as the coincidental survival of an individual strain in host tissue using properties that are designed for life in an entirely different habitat. In that case, the host's infection control is largely based on innate immunity, and the etiologic agent is not transmitted after infection, and thus fungal evolution is not possible. Primary pathogens encompass two types, depending on their mode of transmission. Environmental pathogens have a double life cycle, and tend to become enzootic, adapted to a preferred host in a particular habitat. In contrast, pathogens that have a host-to-host transmission pattern are prone to shift to a neighboring, immunologically naive host, potentially leading to epidemics. Beyond these prototypical life cycles, some environmental fungi are able to make large leaps between dissimilar hosts/habitats, probably due to the similarity of key factors enabling survival in an entirely different niche, and thus allowing a change from opportunistic to primary pathogenicity. Mostly, such factors seem to be associated with extremotolerance.

Passive epidemiological surveillance in wildlife in Costa Rica identifies pathogens of zoonotic and conservation importance

Epidemiological surveillance systems for pathogens in wild species have been proposed as a preventive measure for epidemic events. These systems can minimize the detrimental effects of an outbreak, but most importantly, passive surveillance systems are the best adapted to countries with limited resources. Therefore, this research aimed to evaluate the technical and infrastructural feasibility of establishing this type of scheme in Costa Rica by implementing a pilot program targeting the detection of pathogens of zoonotic and conservation importance in wildlife. Between 2018 and 2020, 85 carcasses of free-ranging vertebrates were admitted for post-mortem and microbiology analysis. However, we encountered obstacles mainly related to the initial identification of cases and limited local logistics capacity. Nevertheless, this epidemiological surveillance scheme allowed us to estimate the general state of health of the country’s wildlife by establishing the causes of death according to pathological findings. For instance, 60% (51/85) of the deaths were not directly associated with an infectious agent. Though in 37.6% (32/85) of these cases an infectious agent associated or not with disease was detected. In 27.1% (23/85) of the cases, death was directly related to infectious agents. Furthermore, 12.9% (11/85), the cause of death was not determined. Likewise, this wildlife health monitoring program allowed the detection of relevant pathogens such as Canine Distemper Virus, Klebsiella pneumoniae, Angiostrongylus spp., Baylisascaris spp., among others. Our research demonstrated that this passive surveillance scheme is cost-effective and feasible in countries with limited resources. This passive surveillance can be adapted to the infrastructure dedicated to monitoring diseases in productive animals according to the scope and objectives of monitoring wildlife specific to each region. The information generated from the experience of the initial establishment of a WHMP is critical to meeting the challenges involved in developing this type of scheme in regions with limited resources and established as hotspots for emerging infectious diseases.

Socioecological vulnerability and the risk of zoonotic disease emergence in Brazil

In developing countries, outbreaks of zoonotic diseases (ZDs) result from intertwined ecological, socioeconomic, and demographic processes that shape conditions for (i) increased contact between vulnerable human population and wildlife in areas undergoing environmental degradation and (ii) the rapid geographic spread of infections across socially vulnerable regions. In Brazil, recent increases in environmental and social vulnerabilities, amplified by economic and political crises, are potential triggers for outbreaks. We discuss Brazilian features that favor outbreaks and show a novel quantitative method for zoonotic risk assessment. Using data on nine ZDs from 2001 to 2019, we found that the most significant causal variables were vegetation cover and city remoteness. Furthermore, 8 of 27 states presented low-level risk of ZD outbreaks. Given the ZD-bushmeat connection, we identified central hunted mammals that should be surveilled to prevent spillover events. The current challenge is to coordinate intersectoral collaboration for effective One Health management in megadiverse countries with high social vulnerability and growing environmental degradation like Brazil.