Invasive wild boar (Sus scrofa) as a functional reservoir for the dynamics of Trichinella in the Patagonia region.

Trichinellosis is a zoonotic disease that has been studied mainly in domestic pigs (Sus scrofa domesticus). The cycle involves infection in domestic and wild fauna, which fulfill complex ecological roles, where Trichinella spiralis is reported in wild boar (Sus scrofa). The objective of this study was to determine the prevalence of trichinellosis in wild boar and evaluate the distance of positive animals to the nearest urbanization areas in Argentina Patagonia. Necropsies were carried out on wild boar hunted in the Nahuel Huapi and Lanín National Parks and surrounding areas. Skeletal muscle samples were collected from 1,694 wild boar and artificial digestion was performed on all samples. Trichinella spp. were found in 96 (5.8%) wild boar (0.2 to 424 Larvae/g). Parasitism in wild boar depends on the distribution of the population in natural and urban areas. Infected wild boar were found near peri-urban areas, demonstrating the importance of routine epidemiological surveillance and sanitary measures in and around cities. More research is needed to identify the Trichinella species that infect wild animals. We recommend the application of active and passive epidemiological surveillance in South America on exotic and native fauna that are hunted and consumed by humans.

A cross-sectional study of free-roaming dogs in a Patagonian city: Their distribution and intestinal helminths in relation to socioeconomic aspects of neighborhoods.

Human and dog health are inextricably linked, and although our relationship with dogs brings numerous benefits for our well-being, it is known that they can transmit disease. Bariloche is a Patagonian tourist city with heterogeneous social composition. This cross-sectional study evaluates the population of free-roaming dogs and their intestinal parasites in relation to the socioeconomic level of the city's human population. Census areas were used as survey units, stratified in three levels according to socioeconomic status. The free-roaming dog population was estimated by walking around each census area. Eight fresh feces per census count area were collected and analyzed using coproparasitological flotation tests, and CoproELISA was used to detect Echinococcus sp. A total of 858 free-roaming dogs were registered along 40.9 km, with significant differences between socioeconomic strata: the highest numbers were found in the lowest income strata. Of the feces collected, 39.2% tested positive for parasites, those associated with a lower socioeconomic level having higher percentages of positive feces and a greater number of species. Eight species of helminths were found, some of which were zoonotic, such as Echinococcus sp., Toxocara canis, and Dibothriocephalus latus. The presence of parasites can be explained by the number of free-roaming dogs per census count area. The free-roaming dogs generally have owners, and their parasitic infection is strongly associated with the socioeconomic level of the population. The main problem is irresponsible pet care, which generates healthy conditions for both dogs and humans. Thus, both dogs and humans deserve effective ethical public policies.

Sarcocystis spp. infection in South American deer huemul (Hippocamelus bisulcus) and pudu (Pudu puda) from Patagonian National Parks, Argentina.

Sarcocystis spp. are intracellular protozoan parasites with heteroxenous life cycles. This study described Sarcocystis spp. infection in adult South American native deer huemul (Hippocamelus bisulcus) and pudu (Pudu puda). Heart, diaphragm, tongue, and skeletal muscle samples were collected from 5 huemuls and 2 pudus, found dead in National Parks. Direct microscopic examination, transmission electron microscopy, PCR, and sequencing were performed. Sarcocystis spp. microscopic thin-walled cysts were identified in 3 huemuls and 1 pudu. Several cysts from 1 huemul and 1 pudu were observed by TEM; ultrastructure was similar to previously reported as cyst wall type 17 and types 2 and 8, respectively. Fragments of the 18S rRNA and cytochrome c oxidase subunit I (cox1) genes were amplified and sequenced from 3 individual cysts from 2 huemuls and 2 cysts from the pudu. The sequences from huemuls showed a high identity among them (> 99%) at both amplified targets. The highest identities were > 99.7% at 18S rRNA and 93% at cox1 with S. tarandivulpes sequences. The 18S rRNA gene sequences from pudus showed an identity > 99.7% with Sarcocystis sp., S. taeniata, and S. linearis sequences, while the cox1 sequences were different, one showing 99.42% identity with S. venatoria and the other 98.22% with S. linearis. A single species, similar to S. tarandivulpes, was identified in all huemul samples while 2 molecularly different Sarcocystis spp. were found in 1 pudu with high similarities to either S. venatoria or to S. linearis, S. taeniata-like, and S. morae. Based on the cox1 sequence identities, at least the Sarcocystis sp. in huemuls might represent a new species, primarily occurring in this host. Additional sarcocyst isolates from both hosts need to be examined molecularly in order to firmly establish whether these species are indeed native to huemuls and/or pudus or are derived from introduced deer species.

A SURVEY OF PARASITE LESIONS IN WILD RED DEER ( CERVUS ELAPHUS) FROM ARGENTINA.

In Argentina there is little information about diseases that affect exotic ungulates and the health risks that they pose to native wildlife, livestock, and humans. The aim of this study was to evaluate the health status of red deer ( Cervus elaphus) in the Nahuel Huapi National Park and surrounding areas in Patagonia, Argentina. During three consecutive hunting seasons, necropsies were performed on 101 red deer, and tissues were examined histologically. The most common lesions were those associated with hepatic and pulmonary parasites. Fasciola hepatica was observed in 15 red deer and was associated with cholangiohepatitis (8%) and/or cholangitis (10%). Dictyocaulus sp. (likely Dictyocaulus eckerti) was associated with interstitial pneumonia (5%), bronchitis (5%), pulmonary emphysema (13%), and bronchus-associated lymphoid tissue hyperplasia (13%). Other findings included Sarcocystis spp. cysts in the myocardium (89%) associated with interstitial, focal, lymphoplasmacytic myocarditis (8%); periportal lymphoplasmacytic hepatitis (8%); hepatic centrilobular necrosis (6%); lymphoplasmacytic interstitial nephritis (25%); and follicular hyperplasia in mediastinal, prescapular, and prefemoral lymph nodes (86%). Our report of lesions caused by endemic parasites of livestock in free-ranging exotic red deer in Patagonia sets the foundation for a health-monitoring and -surveillance system of wildlife in this region, which is essential for the sustainable management of threatened Argentinean native fauna.

Sarcocystosis in wild red deer (Cervus elaphus) in Patagonia, Argentina.

Sarcocystis spp. are protozoan parasites with a heteroxenous life cycle, which produce cysts in the muscle of herbivorous animals. In these animal species, sarcocystosis is frequently asymptomatic, although it may occur with high prevalence. Seven Sarcocystis spp. have been described in red deer (Cervus elephus). The aim of this study was to determine the prevalence of sarcocystosis, and to perform the morphological and molecular characterization of Sarcocystis spp. found in wild red deer of the Nahuel Huapi National Park (NHNP), Patagonia, Argentina. Full necropsies of 62 red deer killed by hunters in the NHNP and neighboring areas were performed. Samples of heart and skeletal muscle were examined histologically and selected samples were also examined by transmission electron microscopy (TEM), PCR and sequencing. Sarcocystis spp. thin walled cysts were detected in 62 % (38/62) of heart, and in 22 % (3/14) of skeletal muscle samples examined histologically. TEM revealed a smooth and thin cyst wall (≤1 µm), with scarce and separated ribbon-like protrusions. A total of three partial and one full 18S ribosomal RNA (rRNA) gene sequences were obtained, and showed the highest identity (≥99 %) with Sarcocystis taeniata, a species described in moose (Alces alces). The morphological and molecular results indicate that red deer in Argentina are frequently infected with S. taeniata, a species for which the definitive host is unknown. The present results also confirm that Sarcocystis spp. using cervids as intermediate host are not host-specific. Further studies are needed to improve the epidemiological knowledge of Sarcocystosis in red deer.

Pododermatitis in captive-reared black stilts (Himantopus novaezelandiae).

A potential cause of pododermatitis ("bumblefoot") was investigated in captive-reared juvenile black stilts at the Department of Conservation "Kaki Recovery Program" at Twizel, New Zealand. To address the importance of substrate, the development of clinical signs in individuals was compared among aviaries that contained rubber matting and/or salt footbaths, and controls. No effect of either experimental manipulation of the environment was apparent on pododermatitis development. With the substrate appearing not to be an initiating factor, and a previous study that indicated that the birds' diet fulfills the nutritional requirements for rearing black stilts in captivity, results of this study suggest that insufficient space for exercise may instead be the cause.

Pulmonary aspergillosis in a great rhea (Rhea americana).

A 5-mo-old great rhea (Rhea americana) gradually became emaciated over a 1-wk period and died. Necropsy revealed several small yellow nodules in the lungs. Microscopically, the nodules consisted of granulomas containing numerous thin, 4-microm-diameter, septate, branching fungal hyphae. Aspergillus fumigatus grew readily on Sabouraud dextrose agar. This report appears to be the first of mycotic pneumonia in great rheas.

Hematology and serum chemistry values of the lesser rhea (Pterocnemia pennata) raised in Patagonian farms (Argentina).

Hematologic and serum chemistry values were determined for chicks, juveniles, and adult farmed lesser rheas (Prerocnemia pennata). Blood samples were taken during March-April 1998 from the brachial veins of lesser rhea, including 64 chicks, 24 juveniles, and 36 adults, raised in Patagonian farms (Argentina). Lesser rhea chicks had significantly lower erythrocyte counts, hematocrit, hemoglobin, red cell indices, and copper than did the juveniles and adult individuals. No significant differences were observed between females and males. Most values were similar to those reported for other ratites. The data obtained provide hematologic and serum chemistry values for lesser rhea from farms.