Utility of thoracic ultrasonography in a rapid diagnosis of angiostrongylosis in young dogs presenting with respiratory distress.

The nematode, Angiostrongylus vasorum is a nematode that lives in the pulmonary arteries of canids and has an obligate gastropod intermediate host. It can cause various clinical signs. with the two most common clinical scenarios consisting of acute respiratory distress and haemorrhagic diathesis, either separately or together. Younger dogs (< 2 years) are overrepresented, and dogs often show pulmonary granulomata (radiographically and pathologically). Thoracic ultrasonography offers a safe, rapid, commonly available, non-invasive means of assessing the lungs. We prospectively examined the utility of thoracic ultrasonography in the diagnosis of angiostrongylosis in 26 client-owned dogs <2 years old, presenting with respiratory distress. We identified small hypoechoic subpleural nodules in 15/26 dogs; 14 of these were subsequently confirmed to have angiostrongylosis by faecal Baermann concentration test, A. vasorum antigen testing or both. The remaining 11 dogs without subpleural nodules had negative faecal analysis and A. vasorum antigen testing and diagnosed with other respiratory diseases. This resulted in a sensitivity of 100% and a specificity of 92% for the detection of angiostrongylosis by thoracic ultrasonography in young dogs presenting with respiratory distress. Our results suggest that thoracic ultrasonography might offer a safe, rapid, relatively accurate diagnostic test for diagnosis of angiostrongylosis in young adult dogs with respiratory distress living in endemic areas.

Selected advanced imaging techniques were unable to quantify in vivo parasitic burden in heartworm-infested dogs.

This prospective exploratory study aimed to determine whether certain noninvasive advanced imaging techniques could estimate parasitic burden in heartworm-infested dogs; a noninvasive method is needed for ethical considerations and permitting longitudinal drug studies. Three cardiac-gated and respiratory-gated 3T MRI techniques and CT pulmonary angiography (CTPA) were performed in three healthy beagles to optimize imaging techniques. Once the imaging techniques were established, a pilot study was performed to determine which one of the MRI techniques would be used in an observer comparison study. Ultimately, spoiled gradient recalled (SPGR)-cine-MRI and CTPA were performed in four and five heartworm-infested dogs, respectively. Heartworms were detected in the pulmonary arteries in all dogs during SPGR-cine-MRI and in no dog during CTPA. However, counting the number of worms was unsuccessful. In conclusion, CTPA and SPGR-cine-MRI were unable to replace necropsy for quantifying parasitic burden in heartworm-infested dogs.

The Occurrence of Physaloptera hispida and a Mastophorus Sp. in Pulmonary Vessels of Hispid Cotton Rats (Sigmodon hispidus) from Georgia, U.S.A.

During 2017-2018, a survey for the rat lungworm, Angiostrongylus cantonensis (Nematoda: Metastrongyloidea), in rodents from Piedmont and Lower Coastal Plains physiographic regions of Georgia was conducted. On 4 occasions, a single worm was recovered from the pulmonary vessels of a single cotton rat (Sigmodon hispidis). One of these worms was identified as a Physaloptera sp. and the remaining 3 as a Mastophorus sp. by morphology. No A. cantonensis were found. Physaloptera (Nematoda: Physalopteroidea) and Mastophorus species (Nematoda: Spiruroidea) are stomach parasites of many wild and domestic animals. This is the first report of these species in the pulmonary vessels of a definitive host. To better characterize these parasites, representative specimens were collected from cotton rat stomachs and identified morphologically and molecularly. Based on partial cytochrome c oxidase subunit 1 (COI) gene sequences, Physaloptera hispida from stomachs were identical to the Physaloptera sp. from the pulmonary vessels. The COI sequences from the Mastophorus sp. from the stomach exhibited a higher degree of variability but confirmed that the pulmonary worms were the same Mastophorus species. Furthermore, sequences of Mastophorus from a coastal site clustered separately from a clade of Mastophorus sequences from cotton rats from a Piedmont site. Our data show that adult worms recovered from pulmonary vessels of cotton rats could be either Physaloptera or Mastophorus sp., indicating that these parasitic worms are not always restricted to the stomach and that worms from pulmonary vessels must be carefully examined to obtain a definitive diagnosis of A. cantonensis infection.

Infection by and Molecular Features of Learedius learedi (Digenea: Schistosomatoidea) in Green Sea Turtles (Chelonia mydas) on the Ogasawara Islands, Japan.

Learedius learedi Price, 1934 , is a blood fluke found in sea turtles, and the adult fluke parasitizes the cardiovascular system of the host. In this study we surveyed 46 green sea turtles, Chelonia mydas, on the Ogasawara Islands, Japan, and blood flukes were detected in the heart and blood vessels of 26 turtles. The flukes were identified as L. learedi based on a detailed morphological description. In addition, molecular identification and characterization of the parasite were performed. The nucleotide sequences of nuclear internal transcribed spacer 2 (ITS2) regions were almost identical to those of L. learedi reported previously, but not to those of Hapalotrema spp., which is the closest related genus. The nucleotide sequences of the 28S ribosomal DNA region formed a single clade with those of the reference L. learedi in the phylogenetic tree, but not with those of Hapalotrema spp. Therefore, the nucleotide sequences of ITS2 and 28S are robust markers for distinguishing L. learedi from other species. The nucleotide sequences of the mitochondrial cytochrome c oxidase subunit 1 (COI) region were analyzed to evaluate the genetic variations in L. learedi. The COI haplotypes revealed the extremely high genetic diversity of the species as well as the host turtles on the Ogasawara Islands. The haplotype frequency in the mitochondrial DNA of the green sea turtles on the Ogasawara Islands is known to be significantly different from those in other Pacific rookeries. Although the number of analyzed flukes is small in this study, no haplotype was close to that in other areas; on the basis of the data, we hypothesized that L. learedi differentiated along with the host turtles on the Ogasawara Islands.

Pulmonary arterial response to Angiostrongylus vasorum in naturally infected dogs: echocardiographic findings in two cases.

BACKGROUND: Angiostrongylus vasorum is a nematode living in the pulmonary arteries of canids. Infected dogs develop severe pulmonary lesions which can potentially lead to pulmonary hypertension (PH). However, reports of PH in natural infected dogs are scant. One of the possible causes of the low prevalence of PH in A. vasorum-infected dogs could be the establishment of large diameter intrapulmonary arteriovenous anastomoses (IPAVAs), which attenuate pulmonary vascular resistance, thus reducing the pulmonary arterial pressure. The present report describes the pulmonary arterial pressure (PAP) response to A. vasorum natural infection in two dogs, assessed by echocardiography and by the saline contrast echocardiographic test (SCE). RESULTS: Both dogs showed clinical signs of respiratory disease. At presentation, case 1 did not show echocardiographic signs of PH and the SCE test was positive proving the presence of IPAVAs. However, at the follow-up visit, despite A. vasorum infection resolution, the same dog showed PH and the SCE test resulted negative, which ruled out the presence of IPAVAs. Case 2 suffered from severe pulmonary arterial hypertension and right-side congestive heart failure since the day of presentation. Saline contrast echocardiography was negative both at the time of presentation and at the follow-up visit. CONCLUSIONS: In the two cases described above, the PH was not associated with IPAVAs. During A. vasorum infection, IPAVAs recruitment mechanism is able to contrast the rise of PAP until a certain level. It probably represents an initial escape mechanism of PH that, over time, exhausts its compensatory capacities allowing PAP to rise and to be detectable on echocardiography.

Canine and feline dirofilariosis in a highly enzootic area: first report of feline dirofilariosis in Greece.

Dirofilaria immitis (heartworm) is enzootic in many areas of the world and quite prevalent in southern European countries. Although dogs are the main host of the parasite, cats may also be infected, and the prevalence of feline dirofilariosis is associated with the respective prevalence of canine infection in any given area. The aim of the present study was to investigate the proportion of D. immitis infection among dogs and cats that were not under any kind of prophylactic treatment and were living in a heartworm enzootic area. In total, 180 stray animals (148 dogs and 32 cats) living in a shelter in Northern Greece were examined for heartworm infection by the Knott's test and serology (antigen and in cats also antibody detection), and additionally echocardiography in the infected cats. Thirty-seven (25%, CI 18.7-32.5%) of the dogs and 3 (9.4%, CI 3.2-24.2%) of cats were found to be positive, by at least one of the tests applied. In 2 of the infected cats, the parasites were also detected by echocardiography. One of the positive cats died suddenly 1 year after diagnosis and at necropsy two decomposing D. immitis were found in the right ventricle and pulmonary artery. This is the first report of confirmed feline dirofilariosis in Greece. The detected proportion of infection in cats was 38% of the respective canine infection in the examined shelter. The results of the present study underline the high risk of infection of cats living in enzootic areas and the imperative character of preventive measures in such conditions.

High prevalence of Angiostrongylus cantonensis (rat lungworm) on eastern Hawai'i Island: A closer look at life cycle traits and patterns of infection in wild rats (Rattus spp.).

The nematode Angiostrongylus cantonensis is a zoonotic pathogen and the etiological agent of human angiostrongyliasis or rat lungworm disease. Hawai'i, particularly east Hawai'i Island, is the epicenter for angiostrongyliasis in the USA. Rats (Rattus spp.) are the definitive hosts while gastropods are intermediate hosts. The main objective of this study was to collect adult A. cantonensis from wild rats to isolate protein for the development of a blood-based diagnostic, in the process we evaluated the prevalence of infection in wild rats. A total of 545 wild rats were sampled from multiple sites in the South Hilo District of east Hawai'i Island. Adult male and female A. cantonensis (3,148) were collected from the hearts and lungs of humanely euthanized Rattus rattus, and R. exulans. Photomicrography and documentation of multiple stages of this parasitic nematode in situ were recorded. A total of 45.5% (197/433) of rats inspected had lung lobe(s) (mostly upper right) which appeared granular indicating this lobe may serve as a filter for worm passage to the rest of the lung. Across Rattus spp., 72.7% (396/545) were infected with adult worms, but 93.9% (512/545) of the rats were positive for A. cantonensis infection based on presence of live adult worms, encysted adult worms, L3 larvae and/or by PCR analysis of brain tissue. In R. rattus we observed an inverse correlation with increased body mass and infection level of adult worms, and a direct correlation between body mass and encysted adult worms in the lung tissue, indicating that larger (older) rats may have developed a means of clearing infections or regulating the worm burden upon reinfection. The exceptionally high prevalence of A. cantonensis infection in Rattus spp. in east Hawai'i Island is cause for concern and indicates the potential for human infection with this emerging zoonosis is greater than previously thought.

Un ocupante insólito de la arteria pulmonar / An Unusual Occupant of the Pulmonary Artery

No disponible

Use of a commercial serologic test for Angiostrongylus vasorum for the detection of A. chabaudi in wildcats and A. daskalovi in badgers.

Three species of the genus Angiostrongylus are known to infect European carnivores: A. vasorum (mainly in canids but also in other carnivores), A. chabaudi (in felids) and A. daskalovi (in mustelids). A. vasorum is responsible for clinically severe disease in domestic dogs, most commonly diagnosed based on fecal examination and serological detection of circulating antigens. Considering the poorly known host range and the challenging larval differentiation in the feces between the three species of Angiostrongylus infecting European carnivores, our aim was to evaluate the cross-reactivity of A. chabaudi and A. daskalovi with A. vasorum using a commercial serologic test developed for domestic dogs. Badgers (Meles meles) (n=10) and wildcats (Felis silvestris) (n=8) were examined between 2015 and 2016 by full parasitological necropsy with subsequent morphological and molecular identification of nematodes and by serology, using IDEXX Angio Detect™ tests. Five out of the ten badgers and two out of the eight wildcats were harboring nematodes in the pulmonary arteries. All nematodes were identified morphologically as A. daskalovi in badgers and A. chabaudi in wildcats, respectively. Serological examination of the plasma samples revealed the positivity of the same animals as found in necropsy. None of the animals negative at necropsy was positive at serology. The 100% correlation between the necropsy results and the serologic positivity to IDEXX Angio Detect™ in badgers infected with A. daskalovi and wildcats infected with A. chabaudi suggest that these rapid tests are able to identify circulating antigens of all species of Angiostrongylus found in European carnivores: A. vasorum, A. daskalovi and A. chabaudi. The possibility for future in-clinic use of this test in domestic cats should be further investigated.

Angiostrongylus chabaudi in felids: New findings and a review of the literature.

Cardiopulmonary infections by Angiostrongylus chabaudi affect domestic and wild felids but, due to limited information on the biology of this nematode, its pathogenicity remains unclear. This article describes the histopathological alterations associated with Angiostrongylus infection in a wildcat from Bulgaria, and reviews current literature on this feline angiostrongylid. Nematodes were isolated from lung lavage and faecal samples of a road killed wildcat in Southern Bulgaria. The morphological identification of parasite larvae as A. chabaudi was confirmed by molecular analysis of part of the 18S ribosomal RNA gene. Upon histopathological examination, severe granulomatous pneumonia, ranging from multifocal to coalescing, and pulmonary vascular lesions were observed. Extensive alveolar collapse, alveolar emphysematous changes, parenchymal haemorrhages and small artery wall hyperplasia were observed in the parenchyma adjacent to the granulomas. Histopathological examination revealed the presence of cross-sections of adult female parasites within the lumen of the pulmonary artery branches, the intima altered markedly by subendothelial proliferation and oedematous changes. This study compliments current knowledge of the pathogenesis of feline angiostrongylosis by A. chabaudi in wildcats, as well as of the distribution of this little-known parasite.

An epidemiological study of A. cantonensis in Jamaica subsequent to an outbreak of human cases of eosinophilic meningitis in 2000.

The infection status of angiostrongylosis in Jamaica was assessed in wild rats and molluscs in the 5 years following the major outbreak of eosinophilic meningitis (EM) in 2000. Parasitological analyses of 297 Rattus rattus and 140 Rattus norvegicus, and 777 terrestrial molluscs from all 14 Parishes on the island revealed Angiostrongylus cantonensis in 32·0% of the rats and in 12·5% of the molluscs. Multivariate analyses confirmed that A. cantonensis occurred significantly more frequently in R. rattus (Odds Ratio [OR] = 1·76), while mean infection intensity in R. rattus was also significantly higher (16·8) than R. norvegicus (11·3) (Mann-Whitney U-test: P = 0·01). Third-stage larvae of A. cantonensis were detected in 29% of 86 Pleurodonte spp.; in 20% of five Poteria spp.; in 18·7% of 369 Thelidomus asper; in 11% of 18 Sagda spp.; and in 6% of 24 veronicellid slugs. Most rodent infections occurred in Northeastern Jamaica (OR = 11·66), a region where infected molluscs were also abundant. Given the prevalence of A. cantonensis infection in rats has significantly increased since the 2000 outbreak, and that a survey of human infections revealed at least ten autochthonous cases in the last 15 years, angiostrongylosis persists as an important zoonosis in Jamaica.

Angiostrongylus chabaudi (Biocca, 1957) in wildcat (Felis silvestris silvestris, S) from Romania.

Angiostrongylus chabaudi is a rare cardio-pulmonary nematode infecting felids. Although almost 60 years have passed since the original description of the species in Italy, this parasite has been seldom found in domestic and wildcats in southern Europe. The present study aims to report a new case of patent A. chabaudi infection in a road-killed wildcat from Maramureș County in Northern Romania. The necropsy revealed the presence of parasites in the pulmonary arteries and the right ventricle, and the fecal examination showed the presence of L1 larvae. Parasites were morphologically and morphometrically characterized as A. chabaudi, showing 100 % nucleotide similarity to an Angiostrongylus sp. originating from a wildcat from Germany and 99 % to A. chabaudi from Italy. This study reports A. chabaudi for the first time in Eastern Europe, expanding knowledge about the distribution range of this species.

First evidence of the European wildcat (Felis silvestris silvestris) as definitive host of Angiostrongylus chabaudi.

Angiostrongylus chabaudi (Strongylida, Angiostrongylidae) is a parasitic nematode described for the first time last century from the pulmonary arteries of six European wildcats (Felis silvestris silvestris) in central Italy. Since then, this parasite remained practically unknown until recently, when immature A. chabaudi have been reported from one wildcat in Germany and two domestic cats (Felis silvestris catus) in Italy. The present report describes the first record of A. chabaudi in Greece and, most importantly, the first known case of patent infection by A. chabaudi. The necropsy of a road-killed F. s. silvestris found near the lake Kerkini, in the municipality of Serres (Macedonia, Greece), revealed the presence of nematodes of both sexes in the right ventricle and the pulmonary artery of the heart. All parasites were mature adults and numerous eggs were present in the uteruses of females. The morphological characteristics of the parasites were consistent with those of A. chabaudi. Moreover, Angiostrongylus-like first stage larvae (L1) were present in the faeces of the animal that was negative for any other cardio-pulmonary parasite. Genetic examination of adult parasites and L1 confirmed the morphological identification as A. chabaudi. Histopathological examination of the lungs showed severe, multifocal to coalescing, chronic, interstitial granulomatous pneumonia due to the presence of adult parasites, larvae and eggs. These findings demonstrate for the first unequivocal time that this nematode reproduces in the European wildcat which should be ultimately considered a definitive host of A. chabaudi. Finally, the L1 of A. chabaudi are described here for the first time, opening new prospects for further studies on this neglected parasite.

Hepatic Shunting of Eggs and Pulmonary Vascular Remodeling in Bmpr2(+/-) Mice with Schistosomiasis.

RATIONALE: Schistosomiasis is a major cause of pulmonary arterial hypertension (PAH). Mutations in the bone morphogenetic protein type-II receptor (BMPR-II) are the commonest genetic cause of PAH. OBJECTIVES: To determine whether Bmpr2(+/-) mice are more susceptible to schistosomiasis-induced pulmonary vascular remodeling. METHODS: Wild-type (WT) and Bmpr2(+/-) mice were infected percutaneously with Schistosoma mansoni. At 17 weeks postinfection, right ventricular systolic pressure and liver and lung egg counts were measured. Serum, lung and liver cytokine, pulmonary vascular remodeling, and liver histology were assessed. MEASUREMENTS AND MAIN RESULTS: By 17 weeks postinfection, there was a significant increase in pulmonary vascular remodeling in infected mice. This was greater in Bmpr2(+/-) mice and was associated with an increase in egg deposition and cytokine expression, which induced pulmonary arterial smooth muscle cell proliferation, in the lungs of these mice. Interestingly, Bmpr2(+/-) mice demonstrated dilatation of the hepatic central vein at baseline and postinfection, compared with WT. Bmpr2(+/-) mice also showed significant dilatation of the liver sinusoids and an increase in inflammatory cells surrounding the central hepatic vein, compared with WT. This is consistent with an increase in the transhepatic passage of eggs. CONCLUSIONS: This study has shown that levels of BMPR-II expression modify the pulmonary vascular response to chronic schistosomiasis. The likely mechanism involves the increased passage of eggs to the lungs, caused by altered diameter of the hepatic veins and sinusoids in Bmpr2(+/-) mice. Genetically determined differences in the remodeling of hepatic vessels may represent a new risk factor for PAH associated with schistosomiasis.

Angiostrongylus vasorum infection in red foxes (Vulpes vulpes) in southern Italy.

Angiostrongylus vasorum (Nematoda: Angiostrongylidae) infection was detected at post-mortem examination in the pulmonary arteries and hearts of 34/102 (33,3%) of red foxes (Vulpes vulpes) from the Campania Region in southern Italy. Pathological changes consisted of granulomatous interstitial pneumonia caused by larvae and intravascular pulmonary adult nematodes. These changes confirm that angiostrongylosis infection in red foxes has a mainly chronic course, in which the infected host may disperse parasite larvae in the environment over its lifetime. Results suggest that the life cycle of A. vasorum is well established in the red fox in the Campania Region representing a potential infection risk for dogs.

Case Report of dirofilariasis in grey wolf in Serbia.

This paper describes a case of dirofilariasis in a two-year old, female grey wolf (Canis lupus lupus). The autopsy revealed the presence of 42 adult forms of Dirofilaria immitis in the pulmonary artery, right ventricle and right atrium, varying in length from 9.5 to 30 cm. This is, to the best of our knowledge, the second report of D. immitis in grey wolves in Serbia. Our finding confirms that the wolf, as a subspecies distinct from the dog, should also be considered as a very suitable definitive host for dirofilariasis.