CANINE HEARTWORM INFECTION AND PROPHYLAXIS USE AMONG PET CARETAKERS FROM THE CUMBERLAND GAP REGION OF TENNESSEE, USA.

The prevalence of infection with canine heartworm (CHW), Dirofilaria immitis, continues to increase across the United States, regardless of the availability of effective and affordable prophylactic products. Current reports of CHW prevalence as estimated by the Companion Animal Parasite Council (CAPC) are thought to under-represent the true magnitude of the issue because pet dogs that do not receive regular veterinary care are often excluded. This study estimated the prevalence of CHW in pet dogs and associated prophylaxis use in pet dogs in the Cumberland Gap Region with a combined doorstep diagnostic testing approach and caretaker survey. Dogs tested (n = 258) during the summers of 2018 and 2019 revealed a 2.3% (6/258) prevalence in the pet dog population with 33% (2/6) being microfilaremic. Questionnaire data from caretaker interviews revealed that 41.8% (108/258) of the dogs were not receiving CHW prophylaxis. Significant predictors of CHW prophylaxis use identified through logistic regression included pet caretaker awareness of CHW as an important health issue and the use of veterinary services in the year preceding participation in the survey. These results underscore the importance of veterinary-mediated client interaction to create risk awareness of CHW disease and association with prophylaxis compliance.

Factors associated with heartworm preventative use in the golden retriever lifetime study.

Introduction: Heartworm disease is preventable with use of heartworm preventatives, but the reported prevalence of heartworm preventative use in the United States is low, some estimates falling around 50% of dogs. However, there are very few estimates of prevalence and its associated factors. Methods: We aimed to estimate prevalence and evaluate factors, including vaccination status, demographics, lifestyle, physical conditions, medications and supplements, and environment and living conditions, for their association with heartworm preventative use in a large dataset from the Golden Retriever Lifetime Study (N = 2,998). Due to the large number of predictors evaluated, we built a bootstrapped elastic net logistic regression model, which is robust to overfitting and multicollinearity. Variables were evaluated by calculating covariate stability (>80%) and statistical significance (p<0.02). Results: In our sample, the prevalence of heartworm use was 39.5%. In our elastic net model, receiving vaccinations (rabies, Bordetella, or any other vaccine), being located in the Southern U.S., being altered, having an infectious disease or ear/ nose/throat system disease diagnosis, being on heartworm preventatives in the past, currently being on tick preventative, having sun exposure in an area with concrete flooring, living in a house with more rooms with carpeted floors, and spending time on hardwood flooring inside were associated with greater odds of heartworm preventative use. Supplementation use and being in the top quartile of height were associated with lower odds of heartworm preventative use. Discussion: The explanatory factors we identified can be used to improve client communication. In addition, target populations for educational interventions and outreach can be identified. Future studies can validate the findings in a more diverse population of dogs.

Serosurvey of arthropod-borne diseases among shelter dogs in the Cumberland Gap Region of the United States.

BACKGROUND: The Cumberland Gap Region (CGR) of the United States is a natural corridor between the southeastern, northeastern, and midwestern regions of the country. CGR has also many species of ticks and mosquitos that serve as competent vectors for important animal and human pathogens. In this study, we tested dogs from six different animal shelters in the CGR for Rocky Mountain spotted fever (RMSF), anaplasmosis, Lyme disease, canine ehrlichiosis and canine heartworm disease. RESULTS: Sera from 157 shelter dogs were tested for antibodies to RMSF agent, Rickettsia rickettsii, using an indirect immunofluorescence assay. Sixty-six dogs (42.0%) were positive for either IgM or IgG, or both IgM and IgG antibodies to R. rickettsii. Moreover, the same set of sera (n = 157) plus an and additional sera (n = 75) from resident dogs at the same shelters were tested using the SNAP 4Dx Plus. Of 232 dogs tested, two (0.9%) were positive for antibodies to Anaplasma phagocytophilum/A. platys, nine (3.9%) were positive for antibodies to Borrelia burgdorferi, 23 (9.9%) for positive for antibodies to Ehrlichia canis/E. ewingii, and 13 (5.6%) were positive for Dirofilaria immitis antigen. Co-infection with two or more etiologic agents was detected in five animals. Three dogs had antibodies to both B. burgdorferi and E. canis/E. ewingii, and two dogs were positive for D. immitis antigen and antibodies to B. burgdorferi and E. canis/E. ewingii. CONCLUSIONS: Shelter dogs in the CGR are exposed to a number of important vector-borne pathogens. Further studies are required to ascertain the roles these animals play in maintenance and transmission of these pathogens.

BASELINE HEALTH AND NUTRITION EVALUATION OF TWO SYMPATRIC NOCTURNAL LEMUR SPECIES (AVAHI LANIGER AND LEPILEMUR MUSTELINUS) RESIDING NEAR AN ACTIVE MINE SITE AT AMBATOVY, MADAGASCAR.

Extractive industries can have significant impacts on ecosystems through loss of habitat, degradation of water quality, and direct impact on floral and faunal biodiversity. When operations are located in sensitive regions with high biodiversity containing endangered or threatened species, it is possible to minimize impact on the environment by developing programs to scientifically monitor the impact on resident flora and fauna species in the early phases of operation so that effects can be mitigated whenever possible. This report presents the baseline health, nutrition, and trace mineral evaluation for 33 Avahi laniger (Eastern wooly lemur) and 15 Lepilemur mustelinus (greater sportive lemur) captured and given complete health evaluations that included the measurement of fat-soluble vitamins and trace minerals in addition to routine complete blood counts, serum chemistries, and parasite evaluations. All lemurs appeared healthy on physical examination despite the presence of minor wounds consistent with interspecies aggression in some individuals. Serum chemistry values were within expected ranges for other lemur species; however, A. laniger erythrocytes were significantly smaller than those of L. mustelinus. Serum nickel values were markedly higher than expected in both species, and selenium, copper, and cobalt levels were higher in L. mustelinus compared with A. laniger at the study site, as well as values for I. indri or P. diadema reported from other locations. Endoparasites and ectoparasites were typical of those reported in other wild lemur species, but load and diversity varied between A. laniger and L. mustelinus despite inhabiting the same forest ecosystem. This baseline assessment provides the foundation for ongoing monitoring.

A retrospective examination of paleoparasitology and its establishment in the Journal of Parasitology.

Volume 95 (2009) of the Journal of Parasitology represented a significant benchmark in the history of paleoparasitology when it received on the cover formal recognition as a topical area for publication. This retrospective examination chronicles the emergence of paleoparasitology, from its origins as an adjunct contribution to the study of prehistoric human populations to its modern expression as a sub-disciplinary interest. The aim of paleoparasitology is to elucidate the temporal and spatial dimensions of parasitism from the fossil record of human and non-human host populations.

Gastrointestinal parasites in relation to host traits and group factors in wild meerkats Suricata suricatta.

Meerkats are one of the most endearing of South African's wildlife celebrities and one of the most highly studied social mammals. However, although parasites are widely recognized as important regulatory factors in animal population, basic knowledge on meerkats' parasites is lacking. Here 100 fresh fecal samples of wild meerkats were examined for the presence of endoparasitic infection. Endoparasitic taxa identified by the presence of eggs or oocysts included Toxocara suricattae, Oxynema suricattae, Pseudandrya suricattae, Cystoisospora sp. and Eimeria sp. Non-specific diagnoses were made for parasites in the Order Strongylida, Order Spirurida and coccidian based on the morphology and size of the eggs and oocysts. The prevalence of infection with T. suricattae and the strongylate species increased with age, while prevalence of coccidia and intensity of infection by the strongylate species increased with decreasing group size, suggesting that stress associated with living in smaller group may increase susceptibility to parasitism. Moreover, parasite communities were more similar between individuals from the same group than between individuals from different groups, suggesting an important role of the environment in parasite infestation. We did not detect any differences between males and females. This study represents the first detailed report of gastrointestinal parasites in wild meerkats, and is a key starting point for future studies on the effect of endoparasite load in the life history of this species.

Liver function in rats acclimatized to a simulated altitude of 5500 m.

We examined the functional and morphological characteristics of the liver in rats acclimatized to a simulated altitude of 5500 m. We examined the metabolic activity and cytoplasmic distribution of liver mitochondria and the capacity of the liver to regenerate after partial hepatectomy. Mitochondrial respiration, oxidative phosphorylation, the respiratory control ratio (RCR), and the morphological characteristics of mitochondria in liver sections were studied after 3 months acclimatization to high altitude (HA). Partial hepatectomy was performed in a subset of animals after 30 days acclimatization to 5500 m. The rate of hepatic regeneration, induction of ornithine decarboxylase and uridine diphosphate glucuronyltransferase (UGT1a1), and plasma bilirubin were measured 24, 48, 72, and 96 hours after hepatectomy. Acclimatization to 5500 m did not affect the mitochondrial respiratory capacity or oxidative phosphorylation. The RCR decreased and acid phosphatase activity increased, which suggests that there were subtle changes in mitochondrial integrity. In addition, mitochondria were distributed more homogeneously in hepatocytes. Hepatic regeneration, which was associated with 25-fold induction of the ornithine decarboxylase, did not differ between controls and the altitude-exposed animals. Plasma bilirubin levels rose markedly 24 hours after hepatectomy, but returned to control levels 48 hours after the operation in the altitude-exposed animals. Thus, the remarkable functional capacity of the liver was retained at simulated HA. Redistribution of hepatic mitochondria seems to play an important role in maintaining hepatic function despite severe cellular hypoxia.

Prevalence of endoparasitic infection in children and its relation with cholera prevention efforts in Mexico.

OBJECTIVE: To investigate whether increased knowledge and use of public health measures promoted for cholera prevention is reflected in lower prevalence of parasitic infection in households in a community in the state of Tamaulipas, Mexico, that is close to the border with the United States of America. METHODS: Between 1994 and 1997, fecal samples from 438 children were collected through convenience sampling and then examined for helminth eggs/larvae and protozoan cysts as biologic indicators of household compliance with recommended cholera prevention measures. The suggested measures were to wash hands before meals and after defecation, to drink purified water, to wash fruits and vegetables, and to eat well-cooked food. In addition, information on the knowledge of and the use of cholera preventive measures was collected by interviews with adult informants in 252 households (186 of those households also provided a fecal sample for analysis). RESULTS: Parasitic infections occurred in 131 of the 438 children (30%), who resided in 79 of the 186 households (42%) that provided fecal samples. Giardia lamblia accounted for 12.5% of all infections. Infections with Hymenolepis nana, Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis, Ancylostoma/Necator, Strongyloides stercoralis, Entamoeba coli, Entamoeba hartmanni, Entamoeba histolytica, Endolimax nana, and Iodamoeba bütschlii were also noted. Infected children were older and more often had an infected sibling. Households with three or more children were also more likely to have an infected child. The primary caregivers in the households where at least one child had a parasitic infection were distinguished by their inability to list at least three cholera prevention measures from memory. CONCLUSIONS: The 42% household prevalence of parasitic infection was relatively high and indicates that some residents of this community may not have fully embraced the public health education efforts promoted for prevention of cholera. The occurrence of nonpathogenic protozoan parasites such as Endolimax nana, Entamoeba coli, Entamoeba hartmanni, and I. bütschlii are important bioindicators for the persistence of unhygienic behaviors that increase the risk of cholera and other infectious diseases dependent on fecal-oral transmission. Information obtained by similar studies can be useful for monitoring compliance with community health and hygiene programs and may indicate the need to intensify educational efforts for the prevention of diarrhea associated with enteric pathogens that cannot be controlled by drugs alone.

Detection of Toxoplasma gondii IgG antibodies in juvenile great grey kangaroos, Macropus giganteus giganteus.

Serial IgG antibody titers to Toxoplasma gondii from three juvenile great grey kangaroos (Macropus giganteus giganteus) with clinical signs consistent with toxoplasmosis were compared with titers from three clinically normal juveniles of similar age. The modified agglutination test was used to measure antibodies to T. gondii. Results demonstrated declining antibody titers to T. gondii in five of six animals. Antibody titers were similar in animals with and without clinical signs. This was interpreted as an indication that maternal IgG antibodies to T. gondii were transferred to juveniles, presumably in milk, rather than an indication of clinical disease. Therefore, clinicians should interpret Toxoplasma serology results in juvenile macropods cautiously.

Prevalence of endoparasitic infection in children and its relation with cholera prevention efforts in Mexico

OBJECTIVE: To investigate whether increased knowledge and use of public health measures promoted for cholera prevention is reflected in lower prevalence of parasitic infection in households in a community in the state of Tamaulipas, Mexico, that is close to the border with the United States of America. METHODS: Between 1994 and 1997, fecal samples from 438 children were collected through convenience sampling and then examined for helminth eggs/larvae and protozoan cysts as biologic indicators of household compliance with recommended cholera prevention measures. The suggested measures were to wash hands before meals and after defecation, to drink purified water, to wash fruits and vegetables, and to eat well-cooked food. In addition, information on the knowledge of and the use of cholera preventive measures was collected by interviews with adult informants in 252 households (186 of those households also provided a fecal sample for analysis). RESULTS: Parasitic infections occurred in 131 of the 438 children (30 percent), who resided in 79 of the 186 households (42 percent) that provided fecal samples. Giardia lamblia accounted for 12.5 percent of all infections. Infections with Hymenolepis nana, Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis, Ancylostoma/Necator, Strongyloides stercoralis, Entamoeba coli, Entamoeba hartmanni, Entamoeba histolytica, Endolimax nana, and Iodamoeba bütschlii were also noted. Infected children were older and more often had an infected sibling. Households with three or more children were also more likely to have an infected child. The primary caregivers in the households where at least one child had a parasitic infection were distinguished by their inability to list at least three cholera prevention measures from memory. CONCLUSIONS: The 42 percent household prevalence of parasitic infection was relatively high and indicates that some residents of this community may not have fully embraced the public health education efforts promoted for prevention of cholera. The occurrence of nonpathogenic protozoan parasites such as Endolimax nana, Entamoeba coli, Entamoeba hartmanni, and I. bütschlii are important bioindicators for the persistence of unhygienic behaviors that increase the risk of cholera and other infectious diseases dependent on fecal-oral transmission...

Increased prevalence of Brucella suis and pseudorabies virus antibodies in adults of an isolated feral swine population in coastal South Carolina.

Two hundred twenty seven adult (> 8 mo) feral swine (Sus scrofa) trapped from April through July 1999 at three locations on a coastal South Carolina (USA) peninsula with restricted ingress and egress were tested for Brucella suis and pseudorabies virus (PRV) antibodies. Approximately 44% of the animals tested positive for B. suis antibodies and 61% tested positive for antibodies to PRV. Previous surveys (1976 and 1992) of feral swine at the same location with similar methods indicated lower seroprevalences (28% and 18% for B. suis and 0% and 19% for PRV). We also found 39% of feral swine seropositive (n = 179) for Trichinella spiralis and 49% seropositive (n = 181) for Toxoplasma gondii. Results of repeated sampling demonstrated that seroprevalence to pathogens can increase with time in an isolated, unhunted population of feral swine suggesting an increased risk to local domestic livestock and potentially to human health.

Diagnosis and Treatment of Trichospirura leptostoma Infection in Common Marmosets (Callithrix jacchus).

Trichospirura leptostoma is a spirurid nematode that inhabits the pancreatic ducts of the common marmoset, Callithrix jacchus, and other New World primates. This parasite was diagnosed in members of this species at the Marmoset Research Center in Oak Ridge, Tennessee colony after their importation from multiple colonies outside the United States. Animals with few parasites in the pancreas had few tissue changes, whereas those with many parasites had moderate to severe fibrosis replacing exocrine tissue. Trichospirura leptostoma can cause chronic pancreatitis, resulting in subclinical to clinical pancreatic insufficiency and secondary malnutrition. Clinical signs of pancreatic insufficiency in affected marmosets included weight loss (despite good appetite) and increased fecal volume. Because earlier reports did not mention treatments, experimental therapeutic regimens were attempted to eliminate infections from the marmosets. In the clinical studies, different doses and treatment periods with ivermectin and fenbendazole were evaluated for therapeutic efficacy. Fenbendazole given daily at a dosage of 50 mg/kg of body weight by gavage for 14 days was the most effective treatment (PI 0.052). Control of the cockroach vector, as well as treatment of infected animals, is needed to prevent Trichospirura leptostoma-induced disease.