First report of Aelurostrongylus abstrusus in St. Kitts.

A 4-month-old intact male domestic shorthair kitten living in St Kitts, West Indies presented with respiratory distress, cachexia, and mucopurulent nasal discharge. Thoracic radiographs revealed a diaphragmatic hernia. The diaphragmatic hernia as well as subpleural pulmonary nodules suspicious for verminous pneumonia were identified during a postmortem examination. Histology showed multifocal to coalescing pyogranulomatous and eosinophilic pneumonia centered on larvae and morulated eggs. The lesion and nematode morphology were consistent with Aelurostrongylus abstrusus. Although Aelurostrongylus abstrusus has been reported worldwide, this is the first report of a metastrongyloid lungworm in cats in St. Kitts and for the West Indies. This case report should increase the awareness of A. abstrusus pneumonia in cats from St. Kitts and other locations in the eastern Caribbean.

Prevalence of helminth and coccidian parasites in Swedish outdoor cats and the first report of Aelurostrongylus abstrusus in Sweden: a coprological investigation.

BACKGROUND: This study was performed in order to gather recent epidemiological data on feline endoparasites in Swedish cats. Faecal samples from 205 outdoor cats were collected by their owners and submitted to the National Veterinary Institute for analysis. The study population was comprised of cats with access to an outdoor environment and with no history of anthelmintic treatment within the last 3 months. Intestinal parasites were detected with a centrifugal flotation technique and Baermann larval sedimentation was performed to detect metastrongylid lungworms. Eggs, larvae and oocysts were identified morphologically by microscopic examination. The following information was collected from cat owners: breed, sex, age, anthelminthic medication last used, observation of cestode proglottids and residential address. RESULTS: Endoparasites were detected in 25% of samples. Eggs of Toxocara cati were found in 21% of samples, followed by taeniid eggs (4%), oocysts of Cystoisospora felis/C. rivolta and capillarid eggs (both 1%). One cat tested positive for Toxoplasma gondii-like oocysts. Larvae of Aelurostrongylus abstrusus were detected in one cat, which is the first published observation of this parasite in Sweden. CONCLUSIONS: The occurrence of intestinal parasites is rather high in outdoor cats in Sweden, which could indicate the need for more intensive deworming routines in the population. Clinical practitioners should be aware of the possible occurence of A. abstrusus in Swedish cats when considering potential causes of respiratory problems in cats in the future.

Protostrongylid parasites and pneumonia in captive and wild thinhorn sheep (Ovis dalli).

We describe health significance of protostrongylid parasites (Parelaphostrongylus odocoilei and Protostrongylus stilesi) and other respiratory pathogens in more than 50 naturally infected Dall's sheep (Ovis dalli dalli) from the Mackenzie Mountains, Northwest Territories (1998-2002) as well as in three Stone's sheep (O. d. stonei) experimentally infected with P. odocoilei (2000-2002). Histological lesions in the brain and distribution of P. odocoilei in the muscles of experimentally and naturally infected sheep were consistent with a previously hypothesized "central nervous system to muscle" pattern of migration for P. odocoilei. Dimensions of granulomas associated with eggs of P. odocoilei and density of protostrongylid eggs and larvae in the cranial lung correlated with intensity of larvae in feces, and all varied with season of collection. Prevalence of P. stilesi based on the presence of larvae in feces underestimated true prevalence (based on examination of lungs) in wild Dall's sheep collected in summer and fall. Similarly, counts of both types of protostrongylid larvae in feces were unreliable indicators of parasitic infection in wild Dall's sheep with concomitant bacterial pneumonia associated with Arcanobacterium pyogenes, Pasteurella sp., and Mannheimia sp. Diffuse, interstitial pneumonia due to P. odocoilei led to fatal pulmonary hemorrhage and edema after exertion in one experimentally infected Stone's sheep and one naturally infected Dall's sheep. Bacterial and verminous pneumonia associated with pathogens endemic in wild Dall's sheep in the Mackenzie Mountains caused sporadic mortalities. There was no evidence of respiratory viruses or bacterial strains associated with domestic ruminants, from which this population of wild sheep has been historically isolated.

Verminous encephalitis in a horse produced by nematodes in the family protostrongylidae.

Parasitic granulomatous eosinophilic inflammation was observed in the central nervous system (CNS) of a 6-month-old Arabian colt from New York state. Inflammation was associated with eggs, larvae, and adult nematodes in the cerebellum. Nematodes had histological characteristics of the superfamily Metastrongyloidea. The presence of dorsal-spined larvae in the CNS was further indicative of infection with a nematode in the family Protostrongylidae. Infections were most compatible with Parelaphostrongylus tenuis but specific diagnosis was not possible. This is the first definitive report of a protostrongylid nematode infection in a horse.

Cathepsin B homologue at the interface between a parasitic nematode and its intermediate host.

Parelaphostrongylus tenuis is a parasitic nematode that causes a debilitating neurologic disease in many North American cervids and domestic livestock species. We produced a PCR-based cDNA library from infective larvae (L3) in order to identify molecules that mediate parasitism. A dominant 1,250-bp amplicon encoded a homologue of cathepsin B cysteine proteases. The sequence incorporated a C29G substitution in the putative active site. Antibodies generated against a recombinant form detected the native protein (PtCPR-1) in Western blot assays of L3, but not adult worm, extracts. Immunohistochemical methods revealed that PtCPR-1 synthesis was restricted to larval stages within the snail intermediate host (Triodopsis sp.), beginning as early as 2 days postinfection (dpi) of snails. The protein was present in the intestine and luminal contents and was lost from larvae over time. Concurrent studies showed that larvae induced an immune response in snails beginning at 1 dpi. Layers of hemocytes encapsulated larvae immediately after infection, and granuloma-like structures formed around parasites in chronic infections. Loss of PtCPR-1 from L3 and its accumulation in host tissues coincided with degeneration of granuloma architecture 90 to 105 dpi. Fully developed L3 emerged from the snail at this time. Our data implicate PtCPR-1 in larval development and possibly in the emergence of P. tenuis from the intermediate host. Emerged L3 survived desiccation and cold stress, suggesting that they could remain infectious in the environment. Molecules promoting emergence would facilitate dispersal of L3 and increase the likelihood of transmission to definitive hosts.

Bronchoalveolar cellular responses of goats following infections with Muellerius capillaris (Protostrongylidae, Nematoda).

The development of Muellerius capillaris in the lung of goats was associated with marked tissue damage and pronounced a cellular reaction. Using broncho-alveolar lavage, the time course of the cellular responses was studied following primary and secondary infection. During the primary infection, there was a biphasic increase in total broncho-alveolar leucocytes (an average of 294.0 +/- 137.0 cells microl[-1]) and in the absolute number of macrophages (182.0 +/- 82.0 cells ul[-1]), lymphocytes (68.5 +/- 35.0 cells microl[-1]), eosinophils (35.3 +/- 16.4 cells microl[-1]) and neutrophils (10.9 +/- 8.7 cell microl[-1]). The lung tissue reaction against worms consisted of a mild infiltration of inflammatory cells. The secondary infection resulted in significant changes in the pulmonary tissue characterised by severe inflammation, leading to widespread granulomatous formation throughout the parenchyma, hyperplasia of cells Type II and a leucocytosis in the broncho-alveolar fluids, with an anamnestic-like response by all cell types. The overall average of the total leucocytes, macrophages, lymphocytes, eosinophils and neutrophils was 529.3 +/- 347.4; 265.4 +/- 148.1; 127.3 +/- 100; 125.4 +/- 100.1 and 14.0 +/- 8.7 cells microl(-1), respectively. Secondary infection also resulted in 56% reduction of worms established in the lungs and 72.3% of L1 larval production. These data suggest that the broncho-alveolar leucocyte response to infection has an immunological basis and that the alveolar macrophages, neutrophils, eosinophils, and lymphocytes may play a significant role in lung resistance against protostrongylid nematodes.

Migratory behaviour and desiccation tolerance of protostrongylid nematode first-stage larvae.

Migration of first-stage larvae (L1) from faeces to soil is a crucial stage in the life-history of protostrongylids transmitted via land snails. Migration of Muellerius cf. capillaris and a Cystocaulus sp. L1 from fresh Nubian ibex (Capra ibex nubiana) faeces (48-50% water content, W.C.) to substrate soils (at 100% r.h., 26 degrees C) was measured experimentally using dry (3 +/- 1% W.C.), wet (31 +/- 0.43% W.C.) and flooded (48.4 +/- 2.45% W.C.) soils. The highest migration rates (90.4 +/- 1.6% migration) in both species occurred on flooded soils when the faecal pellet W.C. reached 90%. The next highest migration rates (43.2 +/- 3.6% migration, at 60% faecal W.C.) were on the wet soils and no migration occurred on dry soil or dry-substrate papers. Migration rates did not differ significantly (P > 0.05) between species. Active Theba pisana were not infected by M. cf. capillaris L1 on dry infested soils, but were infected following rehydration of the same soils. By day 10, L1 of M. cf. capillaris demonstrated lower survival rates in water and in 97% and 76% r.h. (74.5%, 15.2% and 1.9%, respectively) than the Cystocaulus sp. (97.5%, 43.8%, 43.3%) and Protostrongylus sp. (97.9%, 43.2%, 23.8%, P < 0.05). All three nematodes had a remarkably high survival rate (> 99% overall survival, by day 10) when exposed directly to 0% r.h. at 23 degrees C. Results demonstrate the ability of L1 to survive extreme desiccation through anhydrobiosis. Migration of L1 from faeces to soil can take place only during rains which coincide with peak activity of land snails in desert habitat.