The current prevalence and potential elimination of the soil transmitted helminth’s from Grenada

OBJECTIVE: This study formed part of a soil transmitted helminth elimination program in Grenada. The study assessed the prevalence of soil transmitted helminths (STH’s) in Grenadian primary school children. DESIGN AND METHODS: A longitudinal study was carried out on students attending 39 out of all 54 (72.2%) primary schools in Grenada, Carriacou and Petite Martinique between March 2013 and December 2014. The schools were randomly selected for inclusion in the study. Zinc Sulphate Floatation with centrifugation and Microscopy was used to assess the prevalence of STH’s in stool samples from Grenadian primary school children. RESULTS: The overall prevalence of STH was 1.3% (95% CI= 0.54-2.72). In 4 of the 8 parishes the prevalence was 0%. The highest prevalence was 3.9% (0.48-13.46) in St. Patrick. The STH identified were Ancylostoma duodenale, Ascaris lumbricoides and Trichuris trichuria. CONCLUSION: The prevalence of STH’s in the initial survey was 1.3%. This low prevalence indicates that the elimination program which utilizes a multi pronged approach including targeted chemotherapy and education may be feasible.

Prevalence, serovars and antimicrobial susceptibility of Salmonella spp. from wild and domestic green iguanas (Iguana iguana) in Grenada, West Indies.

Cloacal swabs from 62 green iguanas (Iguana iguana), including 47 wild and 15 domestic ones from five parishes of Grenada, were sampled during a 4-month period of January to April 2013 and examined by enrichment and selective culture for the presence of Salmonella spp. Fifty-five per cent of the animals were positive, and eight serovars of Salmonella were isolated. The most common serovar was Rubislaw (58.8%), a serovar found recently in many cane toads in Grenada, followed by Oranienburg (14.7%), a serovar that has been causing serious human disease outbreaks in Japan. Serovar IV:48:g,z51 :- (formerly, S. Marina) highly invasive and known for serious infections in children in the United States, constituted 11.8% of the isolates, all of them being from domestic green iguanas. Salmonella Newport, a serovar recently found in a blue land crab in Grenada, comprised 11.8% of the isolates from the green iguanas. The remaining four less frequent serovars included S. Javiana and S. Glostrup. Antimicrobial susceptibility tests conducted by a disc diffusion method against amoxicillin-clavulanic acid, ampicillin, cefotaxime, ceftazidime, ciprofloxacin, enrofloxacin, gentamicin, nalidixic acid, streptomycin, tetracycline and trimethoprim-sulfamethoxazole showed that drug resistance is minimal, with intermediate susceptibility, mainly to streptomycin, tetracycline and cefotaxime. This is the first report of isolation and antimicrobial susceptibilities of various Salmonella serovars from wild and domestic green iguanas in Grenada, West Indies.

Existence of Angiostrongylus cantonensis in rats (Rattus norvegicus) in Grenada, West Indies.

The zoonotic rat lung worm, Angiostrongylus cantonensis is endemic to Asia, North America, Africa and Australia. The parasite is expanding geographically and has recently been recorded in some of the Greater Antilles in the northern part of the Caribbean. In this study A. cantonensis is reported for the first time in the Lesser Antilles in one of the southernmost islands, Grenada. Between September 2005 and September 2006, 192 rats (Rattus norvegicus) were trapped throughout the island. The rats were anesthetized, exsanguinated, necropsied and the lungs were fixed whole in 10% buffered formalin, trimmed, processed, cut at 3microm, stained with hematoxylin and eosin and examined microscopically. A total of 45 (23.4%) of the 192 rats examined were found to be infected with A. cantonensis and adult worms were found in the cardiopulmonary system of one of the rats. Microscopically, pulmonic lesions, consisting of pulmonary thrombosis, hypertrophy of pulmonary arteries and granulomatous pneumonia were associated with intralesional adults, larvae and embryonated eggs of A. cantonensis. An incidental finding of variably sized (2-7mm) solitary to multiple cysts containing larvae of Taenia taeniaformis were seen in the livers of 57 rats. This report of A. cantonensis in Grenada provides evidence of the further global expansion of this important zoonotic parasite and the public health implications of this discovery is discussed.

Prevalence of gastrointestinal parasites in free-range poultry in Grenada, West Indies.

Rural poultry production systems in Grenada are based on the scavenging indigenous domestic fowl (Gallus domesticus), the predominant species in the poultry sector. This study was done to establish the species and frequency of gastrointestinal parasites in 106 free-ranges chickens ages between 1-2 years, and collected from 13 households. Three nematodes and one tapeworm were identified: Gongylonema ingluvicola (29.2%); Ascaridia galli (10.3%); Heterakis gallinarum (4.7%); Capillaria contorta (2.83%); Railietina tertagona (38.6%). Helminth infections in free-range chickens, even when they occur in low numbers, may result in subclinical disease. High numbers can produce clinical disease. Further studies may be required to devise appropriate prevention and control methods, with improved management systems. This is the first report of gastrointestinal parasites of free-ranging poultry in Grenada.

Prevalence of gastrointestinal parasites in free-range poultry in Grenada, West Indies.

Rural poultry production systems in Grenada are based on the scavenging indigenous domestic fowl (Gallus domesticus), the predominant species in the poultry sector. This study was done to establish the species and frequency of gastrointestinal parasites in 106 free-ranges chickens ages between 1-2 years, and collected from 13 households. Three nematodes and one tapeworm were identified: Gongylonema ingluvicola (29.2%); Ascaridia galli (10.3%); Heterakis gallinarum (4.7%); Capillaria contorta (2.83%); Railietina tertagona (38.6%). Helminth infections in free-range chickens, even when they occur in low numbers, may result in subclinical disease. High numbers can produce clinical disease. Further studies may be required to devise appropriate prevention and control methods, with improved management systems. This is the first report of gastrointestinal parasites of free-ranging poultry in Grenada.

Neospora caninum detected in feral rodents.

The role of rodents in the epidemiology of neosporosis was investigated by assaying brain tissue of feral mice (Mus musculus) and rats (Rattus norvegicus) for Neospora caninum. Both mouse and rat brain tissue were extracted for total DNA, and subjected to two different N. caninum-specific nested polymerase chain reaction (PCR) assays. A portion of brain tissue from the mice and rats were also assayed for N. caninum in gerbils or gamma-interferon gene knockout (KO) mice. Of the 105 feral mice tested, 10% were positive in the N. caninum-specific PCR assays. Of the 242 rats tested, 30% were positive in both assays. Although mice and rats had N. caninum by PCR testing, clinical signs of N. caninum infection were not observed nor were N. caninum parasites observed in gerbils or KO mice inoculated with the rodent brain tissue.

Investigation of Neospora sp. and Toxoplasma gondii antibodies in mares and in precolostral foals from Parana State, Southern Brazil.

Antibodies to Neospora sp. and Toxoplasma gondii were measured in mares and precolostral foals from a farm in Parana State, Brazil. An indirect fluorescent antibody test (IFAT) was used to determine specific antibodies. Three sampling points, 2003, 2004 and at parturition were included in the study, but not all horses are represented at a parturition time point. In 2003, antibodies to Neospora were detected in 17 mares (47%) at 1:50 dilution and in 5 mares (13.8%) at 1:100 dilution. In 2004, antibodies to Neospora were found in 11/36 (30%) horses with titers of 1:50 and in 6 mares (16.6%) at 1:100 dilution. The prevalence of antibodies against T. gondii was 2.7% in mares, either in 2003 and 2004. Evidence for the role of Neospora sp. in equine reproduction failure was not observed in the farm. Immunoglobulin G antibodies to Neospora were found in two of the nine precolostrum foals. Four seronegative foals were born from seronegative mothers, and three seronegative foals were born from seropositive mothers (1:50). Two seropositive precolostrum foals were born from seropositive mothers (1:50). The foals were born clinically normal, and T. gondii antibodies were not detected in their serum samples. The total immunoglobulins values detected on seronegative precolostrum foals were lower than the levels observed in the seropositive foals. This data warrants additional studies to differentiate N. hughesi and N. caninum serologically and determination if these parasites were associated with equine neurological disease and reproductive failure.

Evaluation of co-morbidity indices in patients admitted for chronic obstructive pulmonary disease.

BACKGROUND: There is limited and conflicting information on the use of co-morbidity instruments to predict mortality in patients with chronic obstructive pulmonary disease (COPD). METHODS: We sought to test the validity of the Charlson Index and another co-morbidity instrument, the Adult co-morbidity evaluation 27 (ACE-27), in patients admitted with COPD exacerbations. Co-morbidity scores were obtained by chart review. Information on mortality was retrieved from the Social Security Death Index. We examined the predictive validity of the Charlson and the ACE-27 using survival analysis. RESULTS: There were 112 patients eligible for the study. The ACE-27 but not the Charlson predicted survival, after adjusting for age, gender, and smoking history in Cox regression, hazard ratio (95% CI) of 1.99 (1.17-3.39). CONCLUSIONS: This study confirms earlier findings that the Charlson Index is not a reliable predictor of mortality in patients with COPD. However, the ACE-27 appears to be useful for predicting survival in this study.

Impact of a computer-based auto-tutorial program on parasitology test scores of four consecutive classes of veterinary medical students.

A "Hard and Soft Tick" auto-tutorial that integrates basic knowledge of the parasite biology with practical aspects of tick identification, clinical presentation, pathology, disease transmission, treatment, and control was developed at the University of Wisconsin-Madison School of Veterinary Medicine. The purpose of this study was to assess impact of the auto-tutorial on parasitology test scores in four classes (1999, 2000, 2001, and 2002) of veterinary students. The analysis revealed a small but significant increase (p = 0.054) in mean percentage examination scores for students who used the tutorial over those who did not.

Infestation of a bird and two cats by larvae of Plodia interpunctella (Lepidoptera: Pyralidae).

The larvae of Plodia interpunctella (Hübner), commonly known as the Indian meal moth, often cause enormous losses in stored food supplies. We present three clinical case reports of accidental infestation by P. interpunctella larvae in two domestic cats and one parakeet. A larva gained entry into the avian host and subsequently migrated to the brain. It was alive, covered with "silk-like" fibers and confirmed to be a fourth instar. Plodia interpunctella larvae were excised with forceps from the subcutaneous tissues of the ear and neck of two cats in a different household. Previous reports of infestation by P. interpunctella larvae in vertebrates are unknown.

Serological diagnosis of neosporosis in a herd of dairy cattle in southern Brazil.

Neospora caninum-specific antibodies were detected in 60 of 172 (34.8%) dairy cattle by enzyme-linked immunosorbent assay (ELISA) in a herd from Parana State, Brazil. The seropositive animals included 47 of 126 (37.3%) adult cows, 7 of 29 (24%) heifers (1-2 yr), 4 of 15 (27%) heifers (5 mo-1 yr), and 2 precolostral samples. Data collected over a 9-yr follow-up period revealed that the proportion of pregnancies ending in abortion was 20% (31/154) among ELISA seropositive cows and 8% (15/193) among seronegative cows. The farm recorded 46 abortions, of which 31 (67.3%) were from seropositive cows. All sera positive by ELISA (n = 60) and sera from cows (n = 11) that were ELISA-negative but that had aborted were tested by the indirect fluorescent antibody test (IFAT) at dilutions from 1:25 to 1:200. All sera from ELISA-positive cows (n = 47) had an IFAT titer of 1:25:35 (74%) of these sera were also seropositive at a dilution of 1:200 (IFAT). Cows seropositive by ELISA had a 4-fold increased risk of having aborted at least once, compared to ELISA-seronegative cows. This association was statistically significant (P = 0.0016). The attributable fraction for this association indicated that approximately 76% of the risk for a cow having a history of abortion was attributable to seroconversion to N. caninum.

Massive Dracunculus insignis infection in a dog.

An 11-year-old 13-kg (28.6-lb) spayed female Cocker Spaniel was examined because of subcutaneous nodules on the hind limbs and ventral aspects of the thorax and abdomen. Focal areas of erythema and pyoderma were associated with the nodules, and purulent exudate could be expressed from a fistula in the nodules. A nematode approximately 20.5 cm in length was isolated from a draining fistula in 1 nodule and identified as Dracunculus insignis. The dog was treated with ivermectin, fenbendazole, and metronidazole, but the owner was still able to recover worms from multiple nodules for the next year.

Further characterization of the TS-4 temperature-sensitive mutant of Toxoplasma gondii in mice.

Maternal transmission of Toxoplasma gondii infection to fetuses is important in human and veterinary medicine. Animals, including mice, have been successfully vaccinated with living tachyzoites of the avirulent, nonpersistent, TS-4 temperature-sensitive mutant of T. gondii and have survived challenge infections. We examined in the murine model the persistence of TS-4 infection, transplacental and transmammary transmission, and virulence in neonates. Bioassays of mouse tissues and histological examination of tissues indicated that no viable organisms were present beyond 14 days after inoculation in adult female mice. The TS-4 mutant was not transmitted transplacentally in mice inoculated at 5, 10, or 15 days of gestation and not transmammarily transmitted in mice inoculated 2 days postpartum. Four groups of mouse pups were inoculated subcutaneously with 2 x 10(4), 2 x 10(5) tachyzoites, or with Hanks' balanced salt solution at 2, 3, or 10 days of age. Severe clinical disease and death were observed in 2- or 3-day-old mice and moderate to severe disease was observed in the 10-day-old mice. Results indicate that the TS-4 mutant can cause disease in young nursing mice but is avirulent for pregnant or nonpregnant adult mice.

Evaluation of the safety and efficacy of vaccination of nursing pigs with living tachyzoites of two strains of Toxoplasma gondii.

The safety of vaccination and persistence and distribution of Toxoplasma gondii stages within tissues following vaccination were examined in 3-day-old nursing pigs vaccinated with living tachyzoites by intravenous and subcutaneous routes of either the TS-4 mutant strain or its parent RH strain of T. gondii. The efficacy of vaccination of nursing pigs with the TS-4 mutant was also examined in pigs challenged orally with oocysts following vaccination. Pigs were vaccinated with 3 x 10(5) living tachyzoites when 3 days old and boosted with 3 x 10(5) living tachyzoites when 17 days old. Group 1 had 2 pigs vaccinated intravenously (i.v.) with Hanks' balanced salt solution (HBSS) and served as a vaccination control. Group 2 and 5 pigs vaccinated i.v. with tachyzoites of the TS-4 mutant; 3 pigs were used to examine the safety, persistence, and distribution of the TS-4 mutant and 2 were used for oocyst challenge. Group 3 had 5 pigs vaccinated i.v. with tachyzoites of the RH strain and all were used to examine the safety, persistence, and distribution of the RH strain within their tissues. Group 4 had 3 pigs vaccinated subcutaneously (s.c.) with tachyzoites of the TS-4 mutant; 1 was used to determine the persistence and distribution of the TS-4 mutant within its tissues and the other 2 pigs were used for GT-1 oocyst challenge studies. Group 5 had 3 pigs vaccinated s.c. with tachyzoites of the RH strain and all were used to examine the safety, persistence, and distribution of the RH strain within their tissues. None of the control pigs or pigs vaccinated with the TS-4 mutant developed clinical signs of disease or died prior to oocyst challenge. The TS-4 mutant was not reisolated from the tissues of vaccinated pigs nor were microscopic lesions present in the tissues of pigs that had been killed and examined at necropsy. Severe disease with clinical signs consisting of dyspnea, inactivity, diarrhea, and ocular lesions was observed in the group 3 pigs vaccinated i.v. with the RH strain. One pig died 7 days after initial vaccination. Microscopic lesions were observed in numerous tissues of all group 3 pigs. Swelling, erythema, and ulcers were observed at the site of inoculation in the group 5 pigs that were vaccinated s.c. with the RH strain. Minimal to no microscopic lesions were observed in these group 5 pigs. The RH strain was reisolated from pigs in both groups vaccinated with this strain.(ABSTRACT TRUNCATED AT 400 WORDS)

Ultrastructure of Isospora suis during excystation and attempts to demonstrate extraintestinal stages in mice.

Transmission electron microscopy was used to examine the structure of the oocysts, sporocysts and sporozoites of Isospora suis during in vitro excystation. Oocysts were ground in a teflon-coated tissue grinder to free most sporocysts and to allow for exposure of oocysts and sporocysts to excystation medium. The suspension of oocysts and sporocysts was incubated at 37 degrees C for 0-45 min in excystation medium. After incubation, the intact oocysts and sporocysts, excysted sporocysts, and sporozoites in the excystation medium were pelleted by centrifugation and fixed for transmission electron microscopy. The oocyst wall was composed of three layers. Treatment with 1.5% (v/v) sodium hypochlorite solution removed the outer layer. The sporocyst wall was composed of two layers, the inner layer of which was interrupted by sutures. During excystation these sutures separated, allowing release of the sporozoites. Sporozoites were elongate and possessed all of the organelles typical of coccidial sporozoites. Tissues from experimentally inoculated outbred Swiss-Webster or inbred BALB/c mice were examined for extraintestinal stages (monozoic cysts) of I. suis by immunoperoxidase staining using specific antisera. Extraintestinal stages were not observed in mice, including those given methylprednisolone acetate.

Filaroides hirthi infection in two related dogs.

Filaroides hirthi infection was diagnosed in 2 related Yorkshire Terriers. Dog 1 had a chronic nonproductive cough, but results of fecal flotation examination were negative. Dog 2 was a 1-year-old female progeny of dog 1. Both dogs came from the same kennel and were raised together for 8 weeks. Dog 2 had generalized demodicosis accompanied by secondary bacterial infection and had been treated with corticosteroids. Dog 2 also was given 68 micrograms of ivermectin, PO, and then 50 mg of fenbendazole/kg, PO, q 24 h for 14 days. After the 14-day treatment, results of 3 fecal examinations were negative for Filaroides sp and other parasites, and the dog improved without complications. Fecal examination of the other dogs in the kennel were negative for F hirthi.