First Evidence of Mammarenavirus in the Giant Fruit Bat (Artibeus lituratus) in Mexico.

<em>Objective</em> To describe the presence of an intraorbital cylindrical osseous structure (a spine) in two animal species: camel (Camelus bactrianus) and dromedary (Camelus dromedaries). A homologous osseous structure was previously observed in the large fruit-eating bat (Artibeus lituratus). <br><em>Procedures</em> The bony anatomy of the orbital cavity was studied and quantified on macerated skulls of 3 camels and 2 dromedaries. Additionally, one macerated skull of a large fruit-eating bat (Artibeus lituratus) was used for comparative purposes. <br><em>Results</em> The anatomic description of these unique intraorbital spine was made while studying the bony orbit of macerated skulls, and was considered homologous to that of the bat based on the same anatomic position (at the bone bridge that separates the optic canal and the sphenorbital fissure) and similarities in shape. We suggest the name optic spine of the sphenoid bone. <br><em>Discussion</em> The novel observation of an optic spine on the sphenoid bone in camels and dromedaries (Artiodactyla), when combined with the previous finding of a similar anatomic structure in a bat (Chiroptera) suborder Microchiroptera, may provide further support to the close proximity of these two apparently very distinct animal orders in the phylogenetic tree, and may contribute to the understanding of bat evolution and provide new directions for future research. The function of this osseous spine remains to be investigated, although we hypothesize that the optic spine of the camelids may serve as an attachment site for extraocular muscles.

HIGHLIGHTS We compared dispersion by two species of bats with two species of birds, and concluded that bats are more efficient dispersers of this columnar cactus.The importance of specific plant-animal interactions for the fitness of the interacting groups is mostly driven by the morphological, physiological and behavioural traits of the two interacting species. This work aims to describe dispersal of seeds of the columnar cactus Stenocereus queretaroensis by its main fruit consumers (bats and birds), using the criteria of legitimacy and efficiency. A disperser is legitimate when seeds pass through the gut without losing germination capability, and is efficient if the seeds are transported to places where they have the potential for germination and establishment as seedlings. We conducted direct observations in order to identify the main consumer species of S. queretaroensis fruits. Seed germination was evaluated by comparing those that pass through the gut of two bat species, Artibeus lituratus and Leptonycteris yerbabuenae, and two bird species, Icterus pustulatus and Melanerpes chrysogenys, using the parameters germination percentage and germination rate. To evaluate seed deposition patterns by bats and birds within the study area, 20 seed traps were set: 10 below the canopies of local trees, and 10 in open spaces. Nine species of bats and 13 species of birds were found to consume S. queretaroensis fruits. The four tested species can be considered legitimate dispersers, but germination percentage differed among these disperser species. Seeds defecated by birds show the highest speed of germination and lowest average time to germinate, compared with control seeds. In terms of deposition patterns, however, the bats dropped the highest number of seeds, and deposited them both under the canopy and in open areas, whereas birds drop a lower amount and under the canopy only.

Tacaribe virus (TCRV) was isolated in the 1950s from artibeus bats captured on the island of Trinidad. The initial characterization of TCRV suggested that artibeus bats were natural reservoir hosts. However, nearly 60 years later experimental infections of Jamaican fruit bats (Artibeus jamaicensis) resulted in fatal disease or clearance, suggesting artibeus bats may not be a reservoir host. To further evaluate the TCRV reservoir host status of artibeus bats, we captured bats of six species in Trinidad for evidence of infection. Bats of all four fruigivorous species captured had antibodies to TCRV nucleocapsid, whereas none of the insectivore or nectarivore species did. Many flat-faced fruit-eating bats (A. planirostris) and great fruit-eating bats (A. literatus) were seropositive by ELISA and western blot to TCRV nucleocapsid antigen, as were two of four Seba’s fruit bats (Carollia perspicillata) and two of three yellow-shouldered fruit bats (Sturnira lilium). Serum neutralization tests failed to detect neutralizing antibodies to TCRV from these bats. TCRV RNA was not detected in lung tissues or lung homogenates inoculated onto Vero cells. These data indicate that TCRV or a similar arenavirus continues to circulate among fruit bats of Trinidad but there was no evidence of persistent infection, suggesting artibeus bats are not reservoir hosts.

We investigated trends in notifiable infectious diseases in both humans and animals during the COVID-19 pandemic in South Korea and compared those data against expected trends had nonpharmaceutical interventions (NPIs) not been implemented. We found that human respiratory infectious diseases other than COVID-19 decreased by an average of 54.7% after NPIs were introduced. On the basis of that trend, we estimated that annual medical expenses associated with respiratory infections other than COVID-19 also decreased by 3.8% in 2020 and 18.9% in 2021. However, human gastrointestinal infectious diseases and livestock diseases exhibited similar or even higher incidence rates after NPIs were instituted. Our investigation revealed that the preventive effect of NPIs varied among diseases and that NPIs might have had limited effectiveness in reducing the spread of certain types of infectious diseases. These findings suggest the need for future, novel public health interventions to compensate for such limitations.

Despite recent interest in land-use and land-cover (LULC) change effects on emerging infectious diseases (EIDs), the debate on global potential health threats remains polarizing. These depend on diverse LULC changes, different types of infectious disease systems, and spatio-temporal scales of studies. Here, using both a bibliometric and scoping review method, we summarize the reliability and availability of published relevant studies on LULC effects on mycobacteria, an important group of infectious bacteria that affect humans and both wild and domestic animals. We make connections of LULC with environmental changes (e.g. soils) that likely lead to an increased risk of mycobacteria spillover to human and other animal populations. An important feature of our review is a focus on research from the richest countries of the world, though some studies have been done in Africa, Asia and South America. Geographically, regions experiencing important LULC transformations, such as many tropical regions of Meso- and South America and Southeast Asia, have been given little or no attention in this important topic. Research on Mycobacterium bovis, and to a larger extent on M. ulcerans, constitutes convincing illustrations of the importance of acknowledging shifts in spatio-temporal scales, from local to global and inter-annual to decadal ones, when evaluating responses of mycobacteria to LULC changes. However, studies on other pathogenic mycobacteria remain very much confined to local and dispersed scales. To date, the role of LULC change effects has not been adequately studied for many human and animal pathogens, and more research and attention to this issue is clearly needed. This review provides a comprehensive set of data on the updates of LULC change and their impact on animal and human mycobacterial infections. It also proposes several research recommendations, in particular to better understand the emergence of mycobacteria in context, by multiplying study sites in different regions of the world and in adopting an ecosystem-based perspective, in order to encourage interdisciplinary research better linking environmental microbiology, veterinary science and medical research.

Studies have demonstrated that ~60%–80% of emerging infectious diseases (EIDs) in humans originated from wild life. Bats are natural reservoirs of a large variety of viruses, including many important zoonotic viruses that cause severe diseases in humans and domestic animals. However, the understanding of the viral population and the ecological diversity residing in bat populations is unclear, which complicates the determination of the origins of certain EIDs. Here, using bats as a typical wildlife reservoir model, virome analysis was conducted based on pharyngeal and anal swab samples of 4440 bat individuals of 40 major bat species throughout China. The purpose of this study was to survey the ecological and biological diversities of viruses residing in these bat species, to investigate the presence of potential bat-borne zoonotic viruses and to evaluate the impacts of these viruses on public health. The data obtained in this study revealed an overview of the viral community present in these bat samples. Many novel bat viruses were reported for the first time and some bat viruses closely related to known human or animal pathogens were identified. This genetic evidence provides new clues in the search for the origin or evolution pattern of certain viruses, such as coronaviruses and noroviruses. These data offer meaningful ecological information for predicting and tracing wildlife-originated EIDs.

The pig: a model for human infectious diseases

The objective of this study was to determine the susceptibility of Arcobacter butzleri isolates to various antimicrobial agents used in the treatment of infectious diseases in humans and animals. Thirty-nine A. butzleri strains isolated from broiler chickens were tested for their susceptibility to 23 antimicrobial agents using a disc diffusion method. All isolates were resistant to aztreonam, cefuroxime sodium, cephalothin, orbenin, oxacillin, penicillin G and trimethoprim/sulphamethoxazol. Of the 39 isolates tested, 26 were also found resistant to amoxycillin, amoxycillin/clavulanic acid and ampicillin. One isolate was resistant to, and four showed intermediate level of resistance to, erythromycin. All isolates were susceptible to amikacin, chloramphenicol, danofloxacin, enrofloxacin, nitrofurantoin, nalidixic acid, tetracyclines and tobramycin. The majority of the isolates were found resistant to antibiotics commonly used for the treatment of infectious bacterial diseases in humans and animals. This study shows that A. butzleri strains vary in their resistance to certain kinds of antibiotics and caution should be taken when choosing a suitable antibiotic for the treatment of disease(s) caused by this organism.

Outbreaks of severe acute respiratory syndrome (SARS) in 2002, Middle East respiratory syndrome in 2012 and fatal swine acute diarrhea syndrome in 2017 caused serious infectious diseases in humans and in livestock, resulting in serious public health threats and huge economic losses. All such coronaviruses (CoVs) were confirmed to originate from bats. To continuously monitor the epidemic-related CoVs in bats, virome analysis was used to classify CoVs from 831 bats of 15 species in Yunnan, Guangxi, and Sichuan Provinces between August 2016 and May 2017. We identified 11 CoV strains from 22 individual samples of four bat species. Identification of four alpha-CoVs from Scotophilus kuhlii in Guangxi, which was closely related to a previously reported bat CoV and porcine epidemic diarrhea virus (PEDV), revealed a bat-swine lineage under the genus Alphacoronavirus. A recombinant CoV showed that the PEDV probably originated from the CoV of S. kuhlii. Another alpha-CoV, α-YN2018, from Rhinolophus sinicus in Yunnan, suggested that this alpha-CoV lineage had multiple host origins, and α-YN2018 had recombined with CoVs of other bat species over time. We identified five SARS-related CoVs (SARSr-CoVs) in Rhinolophus bats from Sichuan and Yunnan and confirmed that angiotensin-converting enzyme 2 usable SARSr-CoVs were continuously circulating in Rhinolophus spp. in Yunnan. The other beta-CoV, strain β-GX2018, found in Cynopterus sphinx of Guangxi, represented an independently evolved lineage different from known CoVs of Rousettus and Eonycteris bats. The identification of diverse CoVs here provides new genetic data for understanding the distribution and source of pathogenic CoVs in China.

Ebola virus disease (EVD) is a complex zoonosis that is highly virulent in humans. The largest recorded outbreak of EVD is ongoing in West Africa, outside of its previously reported and predicted niche. We assembled location data on all recorded zoonotic transmission to humans and Ebola virus infection in bats and primates (1976–2014). Using species distribution models, these occurrence data were paired with environmental covariates to predict a zoonotic transmission niche covering 22 countries across Central and West Africa. Vegetation, elevation, temperature, evapotranspiration, and suspected reservoir bat distributions define this relationship. At-risk areas are inhabited by 22 million people; however, the rarity of human outbreaks emphasises the very low probability of transmission to humans. Increasing population sizes and international connectivity by air since the first detection of EVD in 1976 suggest that the dynamics of human-to-human secondary transmission in contemporary outbreaks will be very different to those of the past.DOI: http://dx.doi.org/10.7554/eLife.04395.001

As associações hospedeiros-parasitos e as taxas de infestação de dípteros ectoparasitos da família Streblidae foram estudadas em morcegos da família Phyllostomidae na Floresta Atlântica no extremo sul do Brasil. Para as espécies mais abundantes de filostomídeos, foi examinado se há diferenças nos valores de prevalência e intensidade média dos ectoparasitos nas diferentes estações do ano e conforme sexo e idade do hospedeiro. Em quatro espécies de filostomídeos (Anoura caudifera (E. Geoffroy, 1818), Artibeus fimbriatus Gray, 1838, Artibeus lituratus (Olfers, 1818) e Sturnira lilium E. Geoffroy, 1810) foram coletados 118 indivíduos de sete espécies de Streblidae (Anastrebla caudiferae Wenzel, 1976, Megistopoda aranea (Coquillett, 1899), Megistopoda proxima (Séguy, 1926), Metelasmus pseudopterus Coquillett, 1907, Paratrichobius longicrus (Miranda Ribeiro, 1907), Trichobius phyllostomae Kessel, 1925 e Trichobius tiptoni Wenzel, 1976). Para A. lituratus, A. fimbriatus e S. lilium, as taxas de infestação foram baixas e houve uma tendência à infestação ser maior no verão e outono, fato provavelmente relacionado à sazonalidade de temperatura na região, que afeta as taxas reprodutivas e a mortalidade dos ectoparasitos. A infestação por P. longicrus em A. lituratus não foi afetada pelo sexo e idade do hospedeiro. Para S. lilium, a infestação por M. proxima não foi afetada por sexo e idade do hospedeiro, com exceção da maior prevalência de ectoparasitos em indivíduos jovens. Os dados indicam que não existem diferenças comportamentais ligadas a sexo e idade do hospedeiro que favoreçam ou comprometam a infestação por Streblidae nestas espécies de morcegos filostomídeos.

Antiviral post-exposure prophylaxis with neuraminidase inhibitors can reduce the incidence of influenza and the risk of symptomatic influenza, but the efficacy of the other classes of antiviral remains unclear. To support an update of WHO influenza guidelines, this systematic review and network meta-analysis evaluated antiviral drugs for post-exposure prophylaxis of influenza. We systematically searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, Global Health, Epistemonikos, and ClinicalTrials.gov for randomised controlled trials published up to Sept 20, 2023 that evaluated the efficacy and safety of antivirals compared with another antiviral or placebo or standard care for prevention of influenza. Pairs of reviewers independently screened studies, extracted data, and assessed the risk of bias. We performed network meta-analyses with frequentist random effects model and assessed the certainty of evidence using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. The outcomes of interest were symptomatic or asymptomatic infection, admission to hospital, all-cause mortality, adverse events related to antivirals, and serious adverse events. This study is registered with PROSPERO, CRD42023466450. Of 11 845 records identified by our search, 33 trials of six antivirals (zanamivir, oseltamivir, laninamivir, baloxavir, amantadine, and rimantadine) that enrolled 19 096 individuals (mean age 6·75-81·15 years) were included in this systematic review and network meta-analysis. Most of the studies were rated as having a low risk of bias. Zanamivir, oseltamivir, laninamivir, and baloxavir probably achieve important reductions in symptomatic influenza in individuals at high risk of severe disease (zanamivir: risk ratio 0·35, 95% CI 0·25-0·50; oseltamivir: 0·40, 0·26-0·62; laninamivir: 0·43, 0·30-0·63; baloxavir: 0·43, 0·23-0·79; moderate certainty) when given promptly (eg, within 48 h) after exposure to seasonal influenza. These antivirals probably do not achieve important reductions in symptomatic influenza in individuals at low risk of severe disease when given promptly after exposure to seasonal influenza (moderate certainty). Zanamivir, oseltamivir, laninamivir, and baloxavir might achieve important reductions in symptomatic zoonotic influenza in individuals exposed to novel influenza A viruses associated with severe disease in infected humans when given promptly after exposure (low certainty). Oseltamivir, laninamivir, baloxavir, and amantadine probably decrease the risk of all influenza (symptomatic and asymptomatic infection; moderate certainty). Zanamivir, oseltamivir, laninamivir, and baloxavir probably have little or no effect on prevention of asymptomatic influenza virus infection or all-cause mortality (high or moderate certainty). Oseltamivir probably has little or no effect on admission to hospital (moderate certainty). All six antivirals do not significantly increase the incidence of drug-related adverse events or serious adverse events, although the certainty of evidence varies. Post-exposure prophylaxis with zanamivir, oseltamivir, laninamivir, or baloxavir probably decreases the risk of symptomatic seasonal influenza in individuals at high risk for severe disease after exposure to seasonal influenza viruses. Post-exposure prophylaxis with zanamivir, oseltamivir, laninamivir, or baloxavir might reduce the risk of symptomatic zoonotic influenza after exposure to novel influenza A viruses associated with severe disease in infected humans. World Health Organization.

The genus Borrelia encompasses spirochetal species that are part of three well-defined groups. Two of these groups contain pathogens that affect humans: the group causing Lyme disease (LDG) and the relapsing fever group (RFG). Lyme disease is caused by Borrelia burgdorferi s.l., which is distributed in the Northern Hemisphere, and relapsing fevers are caused by Borrelia spp., which are found in temperate and tropical countries and are an emerging but neglected pathogens. In some departments of Colombia, there are records of the presence of Borrelia sp. in humans and bats. However, little is known about the impact and circulation of Borrelia spp. in the country, especially in wildlife, which can act as a reservoir and/or amplifying host. In this context, the objective of our research was to detect and identify the Borrelia species present in wild mammals in the departments of Caldas and Risaralda in Colombia. For morphological detection, blood smears and organ imprints were performed, and molecular identification was carried out through a nested PCR directed on the flagellin B (flaB) gene. A total of 105 mammals belonging to three orders (Chiroptera, Didelphimorphia and Rodentia) were analyzed, of which 15.24% (n = 16) were positive for Borrelia. Molecularly, the presence of Borrelia burgdorferi s.s. in lung tissues of Thomasomys aureus and blood of Mus musculus (Rodentia) was detected, with 99.64 and 100% identity, respectively. Borrelia sp. genospecies from a clade branch of a bat-associated LDG sister group were identified in seven individuals of bat species, such as Artibeus lituratus, Carollia brevicauda, Sturnira erythromos, and Glossophaga soricina. Furthermore, two Borrelia genospecies from the RFG in seven individuals of bats (A. lituratus, Artibeus jamaicensis, Platyrrhinus helleri, Mesophylla macconnelli, Rhynchonycteris naso) and rodents (Coendou rufescens, Microryzomys altissimus) were documented. Additionally, the presence of a spirochete was detected by microscopy in the liver of a Sturnira erythromos bat specimen. These results contain the first molecular evidence of the presence of B. burgdorferi s.s. in South America, which merits the need for comprehensive studies involving arthropods and vertebrates (including humans) in other departments of Colombia, as well as neighboring countries, to understand the current status of the circulation of Borrelia spp. in South America.

A majority of emerging infectious diseases in humans are zoonoses. Understanding factors that influence the emergence and transmission of zoonoses is pivotal for their prevention and control. Toxoplasma gondii is one of the most widespread zoonotic pathogens known today. Whereas only a few genotypes of T. gondii dominate in the Northern Hemisphere, many genotypes coexist in South America. Furthermore, T. gondii strains from South America are more likely to be virulent than those from the Northern Hemisphere. However, it is not clear what factor(s) shaped modern-day genetic diversity and virulence of T. gondii Here, our analysis suggests that the rise and expansion of farming in the past 11,000 years established the domestic cat/mouse transmission cycle for T. gondii, which has undoubtedly played a significant role in the selection of certain linages of T. gondii Our mathematical simulations showed that within the domestic transmission cycle, intermediately mouse-virulent T. gondii genotypes have an adaptive advantage and eventually become dominant due to a balance between lower host mortality and the ability to superinfect mice previously infected with a less virulent T. gondii strain. Our analysis of the global type II lineage of T. gondii suggests its Old World origin but recent expansion in North America, which is likely the consequence of global human migration and trading. These results have significant implications concerning transmission and evolution of zoonotic pathogens in the rapidly expanding anthropized environment demanded by rapid growth of the human population and intensive international trading at present and in the future.

During mammalian pregnancy and lactation, the maternal demand for calcium is increased to satisfy fetus and newborn skeletal growth. In addition to the dietary intake, females use the calcium contained in their bones to supply this increased demand, leading to a decrease in maternal bone mineral content. In reproductive insectivorous female bats, bone loss has been described as a physiological cost of reproduction, due to the reported increased risk of bone fracture. This physiological cost may be the mechanism underlying the conflict between increasing litter size and maintaining wing skeletal integrity, which would help to explain the small litter size of most bat species. If bone loss is a linking cost between reproduction and survival in bats, and most bat species have small litter sizes, one would expect to find a loss of bone and an increasing probability of bone fracture during pregnancy and lactation in other non-insectivorous bats. In this study, we tested for the existence of this cost in the Great-fruit eating bat, Artibeus lituratus. We analyzed trabecular structure, bone strength and bone mineral content for the humerus bone, hypothesizing that bone loss during reproduction in females would increase the risk of fracture. Our results showed a decrease of 22–31% in bone trabecular area in lactating females, rapidly compensated following weaning. Bone strength did not differ among reproductive and non-reproductive groups and seems to be more influenced by bone organic components rather than mineral contents. Since we observed bone loss during reproduction yet the humerus strength seems to be unaffected, we suggest that bone loss may not represent a physiological cost during reproduction for this frugivorous bat.