Sarcoptic mange outbreak decimates South American wild camelid populations in San Guillermo National Park, Argentina.

Sarcoptic mange epidemics can devastate wildlife populations. In 2014, mange was first detected in vicuñas (Vicugna vicugna) and guanacos (Lama guanicoe) in San Guillermo National Park (SGNP), Argentina. This study describes the temporal dynamics of the outbreak, its effects on the park's wild camelid populations between 2017-2019, and investigates the potential source of the epidemic. From May 2017 to June 2018, transect surveys indicated a sharp decrease in the density of living vicuñas and guanacos by 68% and 77%, respectively. By April 2019 no vicuñas or guanacos were recorded on transect surveys, suggesting their near-extinction in the park. Clinical signs consistent with mange (e.g., intense scratching, hyperkeratosis, alopecia) were observed in 24% of living vicuñas (n = 478) and 33% of living guanacos (n = 12) during surveys, as well as in 94% of vicuña carcasses (n = 124) and 85% of guanaco carcasses (n = 20) examined. Sarcoptes scabiei was identified as the causal agent by skin scrapings, and the cutaneous lesions were characterized by histopathology (n = 15). Genetic characterization revealed that mites recovered from seven vicuñas (n = 13) and three guanacos (n = 11) shared the same genotype, which is consistent with a single source and recent origin of the epidemic. Tracing the potential source, we identified a governmental livestock incentive program which introduced llamas (Lama glama) in areas adjacent to SGNP in 2009, some of which had alopecic scaling consistent with sarcoptic mange. Though at the time of our study no llamas with mange were available for confirmatory sampling, we hypothesize that the introduction of mange-infected llamas may have triggered the outbreak in wild camelids. This unprecedented event in SGNP had devastating effects on dominating herbivores with potentially profound cascading effects at the community and ecosystem levels.

Positively selected variants in functionally important regions of TLR7 in Alouatta guariba clamitans with yellow fever virus exposure in Northern Argentina.

BACKGROUND: In 2007-2009, a major yellow fever virus (YFV) outbreak in Northern Argentina decimated the local howler monkey (Alouatta) population. AIMS: To evaluate whether the surviving howler monkeys possess advantageous genetic variants inherited from monkeys alive prior to the YFV outbreak, we explored the relationship between Toll-like receptor (TLR) 7 and TLR8 gene variation and YFV susceptibility. METHODS: We used samples from Alouatta individuals in Misiones, Argentina alive before the YFV outbreak, individuals that died during the outbreak, and individuals that survived the outbreak and are alive today. We measured genetic divergence between Alouatta YFV exposure groups and evaluated Alouatta-specific substitutions for functional consequences. RESULTS: We did not find different allele frequencies in the post-YFV exposure Alouatta group compared to the pre-exposure group. We identified three nonsynonymous variants in TLR7 in Alouatta guariba clamitans. Two of these substitutions are under positive selection in functionally important regions of the gene. DISCUSSION AND CONCLUSIONS: Our results did not indicate that surviving howler monkey spossess advantageous genetic variants at greater frequency than those alive before the YFV outbreak. However, the positively selected unique coding differences in A. guariba clamitans are in the region important in pathogen detection which may affect YFV resistance. Morework is necessary to fully explore this hypothesis.

Lead pollution from hunting ammunition in Argentina and current state of lead shot replacement efforts.

Waterfowl hunting in Argentina is a profitable industry that attracts hunters from all over the world. Most hunting occurs as high-end hunting tourism, through which registered outfitters service predominantly foreign clients on private lands. Lead pollution from hunting ammunition is increasingly recognized as a significant local problem, impacting wildlife, aquatic and terrestrial habitats, and extending to vulnerable human rural communities. Regulatory frameworks that restrict lead shot use are a budding success story but remain challenged by their constrained geographic range and limited compliance rooted in unavailable nontoxic ammunition. Changes in hunting practices in Argentina are long overdue.

Lead pollution from waterfowl hunting in wetlands and rice fields in Argentina.

The pollution of wetlands by lead derived from waterfowl hunting with lead shot was investigated. We determined soil pellet density and Pb concentration in soil, water and vegetation in natural wetlands and rice fields in central-eastern Santa Fe province, Argentina. Pellet density varied greatly among hunting sites (between 5.5-141 pellets/m(2)) and pellets were present in some control sites. Soil Pb concentration in most hunting sites (approximately 10-20 mg kg(-1)) was not much higher than in control sites (~5-10 mg kg(-1)), with the exception of the site with highest pellet density, which also had a high Pb soil concentration. In water, on the other hand, Pb concentration was similar in all sites (~4-7 µg L(-1)), both control and hunting, and higher than reference values for aquatic media. Lead was also present in vegetation, including grasses and rice crops, in almost all cases. Most soil-collection sites were slightly acidic, and were frequently flooded. These results strongly suggest that metallic Pb from spent shot is oxidized and dissolved due to wetland conditions. Thus, the pollutant is readily mobilized and distributed across all wetland areas, effectively homogenizing its concentration in locations with and without hunting activities. The replacement of lead by nontoxic materials in pellets appears to be the only effective way to prevent Pb pollution in wetlands.

New hosts and localities for helminths of carnivores in Argentina.

A total of 111 samples (43 faeces and 79 gastrointestinal tracts) of 14 wild carnivore species from 12 Argentine provinces were analyzed. Helminth eggs were identified in 73% of the faecal samples and adult worms were recovered from 81% of the gastrointestinal tracts. We found 19 helminth species. Among the most frequent findings were parasites of domestic carnivores, namely Toxocara canis, Toxocara cati, Toxascaris leonina, Ancylostoma caninum, Ancylostoma tubaeforme and Uncinaria stenocephala. In addition, new hosts are reported for 6 nematode species and 5 helminth species are recorded for the first time in Argentina: Aonchotheca putorii, Molineus brachiurus, Cyathospirura chevreuxi, Physaloptera praeputialis and Oncicola martini.

Lead exposure affects health indices in free-ranging ducks in Argentina.

Numerous experiments under controlled conditions and extensive investigation of waterfowl die-offs have demonstrated that exposure to lead from spent gunshot is highly detrimental to the health of waterfowl. However, few studies have focused on examining the more subtle sub-lethal effects of lead toxicity on ducks in non-experimental settings. In our study, the health of ducks exposed to varying amounts of lead under natural conditions was assessed by correlating individual lead exposure with relevant indices of health. Based on hunter-killed wild ducks in Argentina, we measured spleen mass, body condition, examined bone marrow smears, and determined Ca and P in bone tissue. In free-ranging live-trapped ducks we determined basic hematology and aminolevulinic acid dehydratase activity. Using multivariate analyses, we found that, when controlling for the potential confounding effect of site type, year, duck species, body mass and age, lead levels in the liver were negatively associated with body condition and spleen mass. Spleen mass was also lower in ducks with higher lead levels in their bones. In live ducks, high blood lead levels were associated with low packed cell volume and red cell morphologic abnormalities. These findings suggest that, despite the lack of recorded lead-induced mortality in the region, lead exposure results in less conspicuous but still significant impacts on the health of ducks, which could have serious implications for their conservation. Moreover, this evidence further supports the need for urgently banning lead shot in the region.

Lead gunshot pellet ingestion and tissue lead levels in wild ducks from Argentine hunting hotspots.

Lead poisoning in waterfowl due to ingestion of lead pellets is a long recognized worldwide problem but poorly studied in South America, particularly in Argentinean wetlands where duck hunting with lead gunshot is extensive. In 2008, we found high pellet ingestion rates in a small sample of hunted ducks. To expand our knowledge on the extent of lead exposure and to assess health risks from spent shot intake, during 2011 and 2012 we sampled 415 hunter-killed ducks and 96 live-trapped ducks. We determined the incidence of lead shot ingestion and lead concentrations in bone, liver and blood in five duck species: whistling duck (Dendrocygna bicolor), white-faced tree duck (D. viduata), black-bellied whistling-duck (D. autumnalis), rosy-billed pochard (Netta peposaca) and Brazilian duck (Amazonetta brasiliensis). The ingestion of lead shot was confirmed in 10.4% of the ducks examined (43/415), with a prevalence that varied by site and year, from 7.6% to 50%. All bone samples (n=382) and over 60% of liver samples (249/412) contained lead concentrations above the detection limit. The geometric mean lead concentration in tissues (mg/kg dry weight) was 0.31 (GSD=3.93) and 3.61 (GSD=4.02) for liver and bone, respectively, and 0.20 (GSD=2.55) in blood (mg/kg wet weight). Lead levels surpassed toxicity thresholds at which clinical poisoning is expected in 3.15% of liver samples, 23.8% of bones and 28% of blood samples. Ducks with ingested lead pellets were much more likely to have high levels of lead in their liver. Rosy-billed pochards were consistently more prone to ingesting lead shot than other duck species sampled. However, whistling ducks showed higher levels of lead in liver and bone. Our results suggest that lead from ammunition could become a substantial threat for the conservation of wild duck populations in Argentina. The replacement of lead by non-toxic shot would be a reasonable and effective solution to this problem.

Exposure to selected Pathogens in to selected pathogens in Geoffroy's cats and domestic carnivores from central Argentina.

Wild carnivores share a high percentage of parasites and viruses with closely related domestic carnivores. Because of increased overlap and potential contact with domestic species, we conducted a retrospective serosurvey for 11 common carnivore pathogens in 40 Geoffroy's cats (Leopardus geoffroyi) sampled between 2000 and 2008 within or near two protected areas in central Argentina (Lihué Calel National Park, La Pampa, and Campos del Tuyú National Park, Buenos Aires), as well as five domestic cats and 11 domestic dogs from catde ranches adjacent to Lihué Calel Park. Geoffroy's cats had detectable antibody to canine distemper virus (CDV), feline calicivirus (FCV), feline coronavirus, feline panleukopenia virus (FPV), Toxoplasma gondii, Leptospira interrogans (serovars Ictero/Icter and Ballum), and Dirofilaria immitis. None of the wild cats had antibodies to feline herpesvirus, feline immunodeficiency virus (FIV), feline leukemia virus, or rabies virus. Domestic dogs had antibodies to CDV, canine adenovirus, canine herpesvirus, and canine parvovirus. Antibodies to FPV, FCV, FIV, and T. gondii were found in domestic cats. We provide the first data on exposure of free-ranging Geoffroy's cats to pathogens at two sites within the core area of the species distribution range, including the first report of antibodies to CDV in this species. We encourage continued monitoring for diseases in wild and domestic carnivores as well as preventive health care for domestic animals, particularly in park buffer zones where overlap is greatest.

Isolation and characterization of an H9N2 influenza virus isolated in Argentina.

As part of our ongoing efforts on animal influenza surveillance in Argentina, an H9N2 virus was isolated from a wild aquatic bird (Netta peposaca), A/rosy-billed pochard/Argentina/CIP051-559/2007 (H9N2) - herein referred to as 559/H9N2. Due to the important role that H9N2 viruses play in the ecology of influenza in nature, the 559/H9N2 isolate was characterized molecularly and biologically. Phylogenetic analysis of the HA gene revealed that the 559/H9N2 virus maintained an independent evolutionary pathway and shared a sister-group relationship with North American viruses, suggesting a common ancestor. The rest of the genome segments clustered with viruses from South America. Experimental inoculation of the 559/H9N2 in chickens and quail revealed efficient replication and transmission only in quail. Our results add to the notion of the unique evolutionary trend of avian influenza viruses in South America. Our study increases our understanding of H9N2 viruses in nature and emphasizes the importance of expanding animal influenza surveillance efforts to better define the ecology of influenza viruses at a global scale.

Squirrel monkey cytomegalovirus antibodies in free-ranging black howler monkeys (Alouatta caraya), Misiones, Argentina.

Serum from four black howler monkeys (Alouatta caraya) was screened for antibodies to seven viruses by dot immunoassay. Cytomegalovirus antibodies were detected in three of four individuals and provide the first evidence of exposure by black howler monkeys to this virus.

Phylogenetic analysis of H6 influenza viruses isolated from rosy-billed pochards (Netta peposaca) in Argentina reveals the presence of different HA gene clusters.

Until recently, influenza A viruses from wild waterfowl in South America were rarely isolated and/or characterized. To explore the ecology of influenza A viruses in this region, a long-term surveillance program was established in 2006 for resident and migratory water birds in Argentina. We report the characterization of 5 avian influenza viruses of the H6 hemagglutinin (HA) subtype isolated from rosy-billed pochards (Netta peposaca). Three of these viruses were paired to an N2 NA subtype, while the other two were of the N8 subtype. Genetic and phylogenetic analyses of the internal gene segments revealed a close relationship with influenza viruses from South America, forming a unique clade and supporting the notion of independent evolution from influenza A viruses in other latitudes. The presence of NS alleles A and B was also identified. The HA and NA genes formed unique clades separate from North American and Eurasian viruses, with the exception of the HA gene of one isolate, which was more closely related to the North American lineage, suggesting possible interactions between viruses of North American and South American lineages. Animal studies suggested that these Argentine H6 viruses could replicate and transmit inefficiently in chickens, indicating limited adaptation to poultry. Our results highlight the importance of continued influenza virus surveillance in wild birds of South America, especially considering the unique evolution of these viruses.

Isolation of Salmonella spp. from yacare caiman (Caiman yacare) and broad-snouted caiman (Caiman latirostris) from the Argentine Chaco.

Presence of Salmonella spp. was evaluated in yacare caiman (Caiman yacare) and broad-snouted caiman (Caiman latirostris) from a ranching facility in the Argentine Chaco. Crocodilian ranching programs are based on captive breeding of wild-harvested eggs and release of excess hatchlings into the wild. Samples for bacterial isolation were collected from 102 captive (35 C. yacare and 67 C. latirostris) and seven free-ranging caiman (four C. yacare and three C. latirositris) between 2001 and 2005 and from three artificially incubated C. yacare wild eggs. Two Salmonella spp. of known zoonotic potential, S. infantis and S. nottingham, were isolated from captive caiman in 2001 and 2002, respectively. This is the first report for S. nottingham in reptiles and of S. infantis in caiman. Salmonella spp. prevalence varied significantly between years, with a 77% prevalence peak in 2002. Although the cause of this increase was not confirmed, we found no correlation with the type of enclosure, caiman species, or body weight. Deteriorated physical condition of caiman hatchlings due to dietary changes in 2002 could have influenced Salmonella spp. shedding. However, external sources such as food, water, or enclosures could not be ruled out. Pathogenic Salmonella spp. present a risk for human infection. Inadvertent introduction of Salmonella spp. or other bacteria into the environment when caiman are released could pose a threat to wild caiman populations. Prophylactic measures to detect and decrease Salmonella spp. presence in caiman ranching facilities are recommended to reduce risk to humans and make caiman-ranching a sound conservation strategy for crocodilian species.

Antibodies to type A influenza virus in wild waterbirds from Argentina.

Limited information exists on avian influenza (AI) virus infection in South American wild birds. As part of a national surveillance program in Argentina, indigenous waterbirds were screened for antibodies to AI virus. From November 2006 to July 2007, serum samples from 540 waterbirds of 12 species were tested for type-specific antibodies to AI virus with the use of a commercially available blocking enzyme-linked immunosorbent assay (bELISA) and the agar-gel immunodiffusion (AGID) test. Thirty-three percent (176/540) of serum samples were positive with the bELISA and 12% (64/540) were positive with the AGID test. The bELISA detected antibodies to AI virus in eight of the 12 species, and the AGID detected positives in only five species. These results provide insight into AI virus circulation in Argentinean waterbirds and preliminary data to guide further surveillance efforts.

Impact of yellow fever outbreaks on two howler monkey species (Alouatta guariba clamitans and A. caraya) in Misiones, Argentina.

Two yellow fever outbreaks (YFOs) occurred in northeastern Argentina between November 2007 and October 2008, seriously affecting populations of two howler monkey species: the brown howler Alouatta guariba clamitans and the black howler Alouatta caraya. Both howlers live syntopically in El Piñalito Provincial Park, Misiones, where four groups (36 individuals) were studied since January 2005. The first dead howlers were found on January 20, 2008, in El Piñalito. Systematic searches found 14 dead howlers within the area (12 from the study groups and two from neighboring groups), with only two young seen on January 25, 2008, and none found since up to December 2008. In October 2008, another YFO hit howler monkey populations from El Soberbio, Misiones. Overall, 59 howlers were found dead in Misiones from November 2007 to December 2008. Thanks to the alert of the howler's death in El Piñalito, a prompt human vaccination campaign started in the area. Wild howler monkey populations from both species are in a delicate situation in Misiones, especially the brown howler, an already endangered species in Argentina and endemic to the Atlantic Forest. If we add the recurrence of YFOs to the reduction of suitable habitat to small fragments, it could be only a matter of time until howler populations disappear from the Upper Paraná Atlantic Forest in Misiones.

Canine distemper infection in crab-eating fox (Cerdocyon thous) from Argentina.

Canine distemper virus (CDV) has been reported worldwide in wild carnivores and has been cited as the cause of population declines in some species. Crab-eating foxes (Cerdocyon thous) from El Palmar National Park, Argentina, were observed either dead or exhibiting clinical neurologic signs. Samples were taken from two individuals that were laterfound tobe positive for CDV by direct immunofluorescence in brain tissue. Based on molecular studies, the CDV strain had a high percentage of identity compared to CDV strains affecting dogsin Argentina. This is the first report of CDV infection in wild carnivores in Argentina.

Recent and chronic exposure of wild ducks to lead in human-modified wetlands in Santa Fe Province, Argentina.

Poisoning of waterfowl due to ingestion of lead pellets is a worldwide problem in areas that are subject to hunting. No studies have assessed exposure of waterbirds to this heavy metal in Argentina, in spite of intense hunting activity, and the fact that only lead ammunition is commercially available. The objective of this study was to evaluate duck exposure to lead by examining gizzard and bone samples collected from 30 wild ducks, 16 Rosy-billed Pochard (Netta peposaca), and 14 Fulvous Whistling-Duck (Dendrocygna bicolor), provided by hunters in northern Santa Fe Province, Argentina, in July 2007. Radiographs, followed by dissection of the gizzards, showed that 31% of the Rosy-billed Pochards and 29% of the Fulvous Whistling-Ducks had ingested lead pellets (between one and four per animal). Lead in bone was found at concentrations associated with detrimental health effects. In spite of the small number of samples in this project, these results indicate high levels of lead exposure (both recent and chronic) in these species. This is the first report of a problem in Argentina that could represent a threat to the health and conservation of native aquatic species, their predators, and the wetlands they inhabit.

First detection of Bacillus anthracis in feces of free-ranging raptors from central Argentina.

Prevalence of anthrax spores in feces of raptors was determined from samples collected in November-December 2000 and April-May 2001 in an agricultural region of Santa Fé province, Argentina. Feces were tested from 48 birds of six raptor species. One of 14 chimango caracaras (Milvago chimango) and one of eight road-side hawks (Buteo magnirostris) tested positive. The prevalence of Bacillus anthracis spores in feces for the six species was 4% (n=48). The prevalence was 7% (n=14) for chimango caracaras, 13% for road-side hawks (n=8), and 0% for the remaining species (Burrowing owl [Speotyto cunicularia] [n=17], Swainson's hawk [Buteo swainsoni] [n=3], Aplomado falcon [Falco femoralis] [n=2], and American kestrel [Falco sparverius] [n=4]). Grouped by their feeding habits, prevalence for scavenger species was not significantly different than for predators (7% vs. 3%, P>0.999). This study provides evidence that in central Argentina scavenger and non-scavenger raptors may have a role in the epidemiology of anthrax. Long-term studies to determine the extent of this potential involvement in the epidemiology of anthrax in central Argentina are required.

Inmovilización química y evaluación de salud de vizcachas salvajes (Lagostomus maximus) en el chaco arido argentino / Chemical restraint and sanitary assessment of wild vizcachas (Lagostomus maximus) in the arid argentin chaco / Contenção farmacologica e avaliação sanitaria de viscachas selvagens (lagostomus maximus) no chaco árido argentino

Con el objetivo de evaluar la salud de vizcachas salvajes (Lagostomus maximus), se capturaron en el Chaco Árido argentino 10 ejemplares y se efectuaron 11 inmovilizaciones con anestesias fijas o inhalatoria. Para las anestesias, se administraron una combinación de tiletamina- zolazepam (n = 7) o una combinación de medetomidina y ketamina (n = 2) o gas isofluorano con un vaporizador portátil creando un circuito semicerrado (n = 2). Los estudios de salud comprendieron hematología, bioquímica sanguínea, análisis parasitológicos y de exposición a agentes infecciosos mediante cultivo y serología. El uso de tiletamina-zolazepam resultó en una pobre calidad anestésica y recuperaciones prolongadas. Por El contrario, el uso de medetomidina-ketamina o de isofluorano, proporcionaron inmovilizaciones más seguras. Se concluye que el protocolo testado de tiletamina-zolazepam no sería recomendable para esta especie, sobre todo en vida libre. La búsqueda de anticuerpos para los agentes infecciosos evaluados resultó negativa, por otra parte, se aisló Listeria innocua serovar 6a em hisopados rectales, se constató infestación con pulgas (Pulex irritans), ooquistes de Eimeria lagostomi, huevos de la Familia Trichostrongylidae y huevos similares a Heteroxynema viscaciae

RESUMO: Com objetivo de avaliar a condição sanitária de viscachas selvagens (Lagostomus maximus), foram capturados, no Chaco Árido argentino, 10 animais e realizadas 11 imobilizações, com anestesia injetável ou inalatória. Empregaram-se três diferentes protocolos: tiletamina-zolazepam (n = 7), metetomidina-cetamina (n = 2) ou isoflurano com vaporizador portátil em sistema semi-fechado (n = 2). A avaliação sanitária consistiu de hematologia, bioquímica sérica, exames parasitológicos e avaliação da exposição a agentes infecciosos por cultura e sorologia. O uso de tiletamina-zolazepam proporcionou má qualidade anestésica e recuperações prolongadas, enquanto a combinação medetomidina-cetamina, possibilitou imobilizações mais seguras. Assim, o protocolo testado de tiletamina-zolazepam não é indicado para esta espécie, especialmente em animais de vida livre. A pesquisa de anticorpos para os agentes infecciosos avaliados foi negativa, mas isolou-se Listeria innocua serovar 6a de suabes retais, e foram encontradas pulgas (Pulex irritans), oocistos de Eimeria lagostomi, ovos de Trichostrongylidae e ovos similares a Heteroxynema viscaciae

ABSTRACT: In order to evaluate the sanitary condition of wild vizcachas (Lagostomus maximus), 10 animals were captured in the Arid Chaco of Argentina and 11 immobilizations were performed through injectable or volatile anesthesia. Three different protocols were used: tiletamine-zolazepam (n = 7), medetomidine-ketamine (n = 2), or isofluorane with a portable vaporizer in a semi-closed circuit (n = 2). The sanitary assessment consisted of hematology, blood chemistry, parasitological analysis, and the assessment of the exposure to infectious agents by culture and serology. The use of tiletamine-zolazepam caused poor anesthetic quality and prolonged recoveries, while the medetomidine-ketamin combination, however, caused safer immobilizations. Thus, the use of the tested protocol of tiletamine-zolazepam is not advisable for this species, mainly for free-ranging animals. The search of antibodies for the evaluated infectious agents was negative, but there was isolated Listeria innocua serovar 6a from rectal swabs , fleas were found (Pulex irritans), oocytes of Eimeria lagostomi, Trichostrongylidae eggs as well as similar Heteroxynema viscaciae eggs.