Cases Of Pythiosis Research Articles

Pitiose cutânea em equídeos no Bioma Amazônico

ABSTRACT: The study aimed to describe the clinicopathological aspects of 37 cases of pythiosis, 34 in horses and three in mules, from properties located in the Amazon biome of Pará, Brazil. The clinical signs observed in the animals were weakness, poor-to-regular nutritional status, pale mucous membranes, itching at the lesion site, and lameness when the limbs were affected. The lesions were located on the lips, nostrils, rib region, thoracic and abdominal walls, scapular, distal limbs, foreskin, perineum and udder. Macroscopically, ulcerative and granulation-tissue-like masses were observed, with fistulous tracts filled with yellowish and foul-smelling serosanguinous discharges. In the biopsy, it was possible to visualize white and firm areas with foci of yellowish necrotic material and hardened masses, called kunkers. The histopathological examination showed a pyogranulomatous inflammatory reaction with the presence of Pythium insidiosum hyphae, which were impregnated with black, confirming the diagnosis of pythiosis in equids in the Amazon biome, being the first report of the disease in mules in the region.

S2.4a Pythiosis: An emerging disease in Hong Kong

S2.4 Veterinary mycology research, September 21, 2022, 3:00 PM - 4:30 PMOomycosis is an emerging disease of humans and animals caused by oomycetes in the Stramenopiles-Alveolata-Rhizaria super group, mainly Pythium insidiosum and occasionally Lagenidium giganteum or Paralagenidum species. In surface freshwater, oomycetes produce motile biflagellate asexual zoospores with marked chemotactic attraction to epithelial surfaces of vertebrate hosts. Infection is the result of encystation and invasion of damaged skin or gastrointestinal mucosa.Of ∼ 4200 cases of pythiosis reported globally between 1980 and 2021 only ∼ 20% involved humans while 80% involved animals, mainly horses, dogs, and cattle. Most human cases occur in India and Thailand, whereas most animal infections were reported in the United States and Brazil. Pythiosis has been reported in mainland China, but the burden of the disease is low and comprises <1% of overall cases in humans.Neither pythiosis nor lagenidiosis has been previously reported in humans or animals in Hong Kong. From January 2018 to January 2022, the Veterinary Diagnostic Laboratory of City University of Hong Kong diagnosed 10 cases of oomycosis (5 canine, 5 feline) after identification of non-parallel walled, irregularly branching, and poorly septate hyphae in the center of necrotic regions of histological sections of formalin-fixed paraffin-embedded tissues (FFPET). Species identity was confirmed by PCR and sequencing of 28S rDNA from DNA extracts of FFPET. There were 8 cases of P. insidiosum and 2 of L. giganteum infection. Serum ELISA was positive for Pythium antibodies in 5/6 cases tested and negative for Pythium/Lagenidium/Paralagenidum antibodies in a German shepherd dog (GSD) with disseminated disease caused by L. giganteum.Affected dogs were young to middle-aged at presentation (9 months to 5 years old). Two dogs had focal cutaneous infections, two had extensive gastrointestinal involvement, and the GSD had disseminated disease with cutaneous, mediastinal, and abdominal involvement.Affected cats were young (8 weeks to 18 months) and presented with subcutaneous/cutaneous disease. Three cats had a distinctive perianal ring of bulging subcutaneous granulation tissue, including one that also had an ulcerated, proliferative and necrotic lesion involving two adjacent hind-limb digits. One cat had facial subcutaneous swelling with mandibular lymph node enlargement and the remaining cat presented with extensive circumferential swelling of one hind limb from the distal paw to the mid-stifle.All cats tested negative for the Feline leukemia virus and Feline immunodeficiency virus. Traumatic or surgical wounds preceding infection were identified in a kitten caught in a rodent glue-trap with skin wounds, in a cat with facial involvement that had an injured globe surgically enucleated, and in a dog with cutaneous pythiosis that had chronic dermatitis.Treatment data were available for one canine case. The GSD with lagenidiosis was treated with combination antimicrobial therapy including voriconazole, terbinafine, minocycline, and azithromycin. The dog responded poorly. Mefenoxam was substituted for voriconazole and hyperbaric oxygen therapy was administered. After initial response, the dog succumbed 4 months from diagnosis. We have had success with the treatment of four feline cases using combination therapy including surgical debridement, immunotherapy with a Pythium vaccine, and combinations of antifungal drugs (posaconazole and terbinafine), and/or antimicrobials (doxycycline/minocycline and azithromycin).

Nested PCR Detection of Pythium sp. from Formalin-Fixed, Paraffin-Embedded Canine Tissue Sections.

Simple SummaryPythium insidiosum is a waterborne fungus-like organism commonly present in tropical and subtropical areas that causes a disease named pythiosis in dogs and other animals. This disease can cause inflammatory lesions on the skin and gastrointestinal tract and, if left untreated, may be fatal. Because this mold lacks the distinctive features of true fungi, it requires specific treatment. Diagnosis of pythiosis is commonly achieved by microscope visualization after staining the tissue sections (histopathology). Although some stains highlight hyphae, these techniques are challenging to distinguish P. insidiosum from other fungi. Our study aimed to develop a molecular technique (nested PCR) to specifically detect P. insidiosum DNA in biopsy specimens to aid in diagnosing this organism. Archived biopsies from 26 dogs suspected of pythiosis were examined by histopathology with special stains and tested by the novel nested PCR. Agreement between histopathology and nested PCR occurred in 18/26 cases. The microscopic examination identified hyphae consistent with Pythium sp. in 57.7% of the samples, whereas the nested PCR detected P. insidiosum DNA in 76.9% of samples, aiding in the sensitivity of the diagnosis of pythiosis in dogs. Using this combination of techniques, we report 20 canine cases of pythiosis over 18 years in Indiana and Kentucky, an unexpectedly high incidence for temperate climatic regions. Thus, we recommend using our nested PCR test in addition to the microscopic examination to increase the sensitivity of the diagnosis.Pythium insidiosum is an infectious oomycete affecting dogs that develop the cutaneous or gastrointestinal form of pythiosis with a poor prognosis. If left untreated, pythiosis may be fatal. This organism is not a true fungus because its cell wall and cell membrane lack chitin and ergosterol, respectively, requiring specific treatment. Identifying the organism is challenging, as a hematoxylin and eosin (H&E) stain poorly stain the P. insidiosum hyphae and cannot be differentiated conclusively from other fungal or fungal-like organisms (such as Lagenidium sp.) morphologically. Our study aimed to develop a nested PCR to detect P. insidiosum and compare it with the traditional histopathologic detection of hyphae. Formalin-fixed, paraffin-embedded (FFPE) tissue scrolls from 26 dogs with lesions suggesting the P. insidiosum infection were assessed histologically, and DNA was extracted from the FFPE tissue sections for nested PCR. Agreement between the histologic stains, (H&E), periodic acid–Schiff (PAS), and/or Grocott methenamine silver (GMS) and the nested PCR occurred in 18/26 cases. Hyphae consistent with Pythium sp. were identified via histopathology in 57.7% of the samples, whereas the nested PCR detected P. insidiosum in 76.9% of samples, aiding in the sensitivity of the diagnosis of pythiosis in dogs. Using this combination of techniques, we report 20 canine cases of pythiosis over 18 years in Indiana and Kentucky, an unexpectedly high incidence for temperate climatic regions. Using a combination of histopathology evaluation and nested PCR is recommended to aid in the accurate diagnosis of pythiosis.

Pythium insidiosum complex hides a cryptic novel species: Pythium periculosum

Early phylogenetic analysis of Pythium insidiosum, the etiologic agent of pythiosis in mammals, showed the presence of a complex comprising three monophyletic clusters. Two included isolates recovered from cases of pythiosis in the Americas (Cluster I) and Asia (Cluster II), whereas the third cluster included four diverged isolates three from humans in Thailand and the USA, and one isolate from a USA spectacled bear (Cluster III). Thereafter, several phylogenetic analyses confirmed the presence of at least three monophyletic clusters, with most isolates placed in clusters I and II. Recent phylogenetic analyses using isolates from environmental sources and from human cases in India, Spain, Thailand, and dogs in the USA, however, showed the presence of two monophyletic groups each holding two sub-clusters. These studies revealed that P. insidiosum possesses different phylogenetic patterns to that described by early investigators. In this study, phylogenetic, population genetic and protein MALDI-TOF analyses of the P. insidiosum isolates in our culture collection, as well as those available in the database, showed members in the proposed cluster III and IV are phylogenetically different from that in clusters I and II. Our analyses of the complex showed a novel group holding two sub-clusters the USA (Cluster III) and the other from different world regions (Cluster IV). The data showed the original P. insidiosum cluster III is a cryptic novel species, now identified as P. periculosum. The finding of a novel species within P. insidiosum complex has direct implications in the epidemiology, diagnosis, and management of pythiosis in mammalian hosts.

Geographic distribution of Pythium insidiosum infections in the United States.

To describe the geographic distribution of infections caused by Pythium insidiosum in dogs, horses, and other animal species in the US. For the last 20 years, we have collected data from cases of pythiosis in 1,150 horses, 467 dogs, and other species (59) from various geographic locations in the US. Due to lost data (from 2006 to 2016), the selected cases include years 2000 to 2005 and 2016 to 2020. The selection of cases was based on infected host clinical features, serum samples demonstrating strong positive anti-P insidiosum IgG titers in serologic assays, and positive results on ≥ 1 of the following diagnostic modalities: microbial culture on 2% Sabouraud dextrose agar, histologic evaluation, PCR assay, and wet mount cytologic evaluation (with potassium hydroxide). Most confirmed P insidiosum infections were found in horses and dogs in the southeastern US. Interestingly, in Texas, no cases were found west of longitude 100°W. Few pythiosis cases were diagnosed in west-coast states. Equine cases were more often diagnosed during summer and fall months, but canine cases were more often diagnosed between September and February. Cases in other species were discovered in the same geographic areas as those in dogs and horses. To our knowledge, this is the first report providing the ecological distribution of P insidiosum infection in affected species in the US. Results of this study illustrated the importance of including P insidiosum in the differential diagnostic scheme of nonhealing skin lesions or intestinal granulomatous masses, particularly in dogs and horses inhabiting or having visited endemic areas.

Global Distribution and Clinical Features of Pythiosis in Humans and Animals.

Pythiosis is a difficult-to-treat infectious disease caused by Pythium insidiosum. The condition is unfamiliar among healthcare workers. Manifestation of pythiosis is similar to other fungal infections, leading to misdiagnosis and delayed treatment. The geographical extent of pythiosis at a global scale is unclear. This study aimed to analyze the clinical information recorded in the scientific literature to comprehensively project epidemiological characteristics, clinical features, and future trends of pythiosis. From 1980 to 2021, 4203 cases of pythiosis in humans (n = 771; 18.3%) and animals (primarily horse, dog, and cow; n = 3432; 81.7%), with an average of 103 cases/year, were recruited. Pythiosis case reports significantly increased in the last decade. Pythiosis spanned 23 tropical, subtropical, and temperate countries worldwide. Some patients acquired pythiosis from a trip to an endemic country. Strikingly, 94.3% of human cases were in India and Thailand, while 79.2% of affected animals were in the U.S.A. and Brazil. Clinical features of pythiosis varied. Vascular and ocular pythiosis were only observed in humans, whereas cutaneous/subcutaneous and gastrointestinal infections were predominant in animals. Mortality depended on host species and clinical forms: for example, none in patients with ocular pythiosis, 0.7% in cows with a cutaneous lesion, 26.8% in humans with vascular disease, 86.4% in dogs with gastrointestinal pathology, and 100% in several animals with disseminated infection. In summary, this study reports up-to-date epidemiological and clinical features of pythiosis in humans and animals. It increases awareness of this life-threatening disease, as the illness or outbreak can exist in any country, not limited to the endemic areas.

Vascular pythiosis caused by Pythium aphanidermatum: the first case report in Asia

BackgroundPythium, soil-borne plant pathogens, are in the class Oomycetes. They are not true fungi, but are related to diatom and algae. There are two human pathogens including P. insidiosum and P. aphanidermatum. To date, only one case of pythiosis caused by P. aphanidermatum has been reported. We present herein the first case of P. aphanidermatum vascular pythiosis in Asia.Case presentationA 47-year-old Thai woman, living in North Thailand, with ß thalassemia/hemoglobin E presented with acute recurrent arterial insufficiency of both legs. Emergent embolectomy with clot removal was performed. The pathology of the clot exhibited noncaseous granulomatous inflammation with many fungal hyphal elements. PCR identified P. aphanidermatum with 100% identity. Final diagnosis is vascular pythiosis. Unfortunately, the patient eventually expired after treatment with itraconazole, terbinafine, azithromycin, and doxycycline.ConclusionsTo date, only one case of pythiosis caused by P. aphanidermatum has been reported. We present herein the first case of P. aphanidermatum vascular pythiosis in Asia.

An initial survey of 150 horses from Thailand for anti-Pythium insidiosum antibodies

IntroductionPythium insidiosum causes a life-threatening infection termed pythiosis in humans and other animals. The organism has been identified in tropical and subtropical environments worldwide. Since 1985, human pythiosis has been increasingly reported from Thailand. Seroprevalence studies estimated that 32,000 Thai people had been exposed to the pathogen. In 2018, the first animal pythiosis case in Thailand was diagnosed in a horse. Here, we investigated the seroprevalence of anti-P. insidiosum antibodies in the Thai equine population. Materials and methodsWe surveyed serum anti-P. insidiosum antibodies in 150 horses distributed across Thailand, using three established serological tests: enzyme-linked immunosorbent assay (ELISA), immunochromatographic test (ICT), and Western blot analysis. ResultsELISA detected the anti-P. insidiosum antibodies in three horses. ICT and Western blot confirmed the presence of the antibodies in one of the ELISA-positive horses. Based on one positive out of 150 horses tested, the seroprevalence of anti-P. insidiosum antibodies in the Thai equine population was 0.7%, which is markedly higher than that in the Thai human population (0.07%), but much lower than that in the Brazilian equine population (11.1%). ConclusionThe seroprevalence of the anti-P. insidiosum antibodies in the equine population suggests a higher incidence of pythiosis in horses than in humans. The antibody surveillance reported by our group was undertaken to promote a better understanding of the epidemiology and host susceptibility of pythiosis in Thailand.

Mastitis by Pythium insidiosum in Mares

Background: Pythiosis is a chronic inflammatory disease caused by the oomycete Pythium insidiosum. This disease has been reported in several species, but most cases occur in horses. In this species, the cutaneous form is more prevalent, with occasional involvement of adjacent lymph nodes and bone tissue. The involvement of the mammary glands was not properly characterized. Therefore, the aim of this study is to describe cases of pythiosis with the involvement of the mammary glands in mares.Case: A retrospective study of all biopsy samples and necropsy examinations of horses, performed at the Animal Pathology Laboratory of the Federal University of Campina Grande from January 2000 to December 2018, was carried out. During the study period, 142 cases of cutaneous pythiosis were identified. Of these, in three the lesions extended to the mammary glands. Mares with 3-, 7- and 12-year-old, mongrel, from the backlands of the Paraiba were affected. On physical examination, the mares presented swollen mammary glands and multifocal wounds, which discharge serosanguinolent secretion. Clinical evolution ranged from 15 to 30 days. The animals had been medicated, but the wounds did not heal and mastectomies were performed. Macroscopically, the mammary glands were enlarged and with multifocal areas of ulceration measuring 1 to 3.5 cm in diameter. At the cut surface, they exhibited fistulous tracts containing kunkers. In the histopathological evaluation, was observed diffuse and marked inflammatory infiltrate of eosinophils extending through the deep dermis and interlobular mammary stroma; and multifocal areas, sometimes focally extensive, of eosinophilic necrosis with intralesional negative images of hyphae. In histological sections stained by periodic acid–Schiff, the walls of the hyphae were weakly stained in blue; but when impregnated by Grocott methenamine silver, they were strongly marked in black and were characterized by semi-parallel walls, rare septations and branching, and a diameter varying from 3-8μm. At immunohistochemistry, the hyphae showed strong cytoplasmic and wall immunostaining for the anti-P. insidiosum antibody.Discussion: The diagnosis of mastitis by P. insidiosum was established based on the epidemiological, clinical, anatomopathological and immunohistochemical findings. Lesions in horses are more frequently located at the extremities of the limbs and the ventral portion of the thoracoabdominal wall. In these cases, it is likely that the lesions have started on the skin adjacent to the udder and have extended to the mammary parenchyma. The intralesional structures known as kunkers have been described in horses, mules, donkeys, and camels, being absent in the other animal species affected. The kunkers are always present in equine pythiosis and allow the establishment of an accurate presumptive diagnosis. Clinically important findings include wounds that discharge serosanguineous secretions and do not heal through conventional treatments. Histological lesions characterized by areas of eosinophilic necrosis with intralesional hyphae, which are weakly stained by PAS and strongly impregnated by GMS, are highly suggestive of pythiosis. Pythiosis is relatively frequent in horses in the backlands of Paraiba, predominantly in the cutaneous form. The involvement of the mammary glands is an uncommon presentation that should be included as a differential diagnosis of mastitis in mares.

Pythium insidiosum em equino: Relato de caso

Pythiosis is a chronic granulomatous condition affecting horses and other species such as dogs, cattle, goats, cats, wild animals and humans. It occurs in regions with tropical, subtropical or temperate climates, and in areas with accumulated water, bathed and lagoons. Brazil is among tropical countries as an endemic site of equine pythose.The etiologic agent in mammals is an oomycete of the Kingdom Stramenopila, Phylum Oomycota, Class Oomycetes, Order Pythiales, Family Pythiaceae, Genus Pythium, Species Pythium insidiosum. It is a parasite of aquatic plants, which through asexual reproduction produces zoospores that can infect animals. It causes great damages in the echinoculture and the prognosis of the disease depends on the extension of the lesions and compromise of structures such as tendons, joints and bone tissues. It is a disease that causes an infectious picture in the skin and subcutaneous region, however can present systemic picture, pulmonary, gastrointestinal, ocular, among others. The disease in horses characterized by eosinophilic granuloma formation with presence of necrotic masses called "kunkers". The “kunkers” present histologically as eosinophilic concretions of varied size, circular shape, irregular contours, composed of hyphae, collagen, arterioles and inflammatory cells. Many protocols for treatment have been used: chemical (antifungals), surgical and immunotherapy. The most appropriate treatment for pythiosis in horses is the surgical removal of granuloma combined with immunotherapy. However, the treatment is complicated by the unique characteristics of the agent that differs from the true fungi in the production of motile zoospores and in the composition of their cell wall. True fungi possess chitin in their wall, while Pythium contains cellulose and β-glucans, which makes it difficult to penetrate the drugs. In this work, it is proposed to report a case of pythiosis diagnosed in an equine attended at the Hospital of Veterinary Clinics (HCV) of UFRGS (Federal University of Rio Grande do Sul). A long and expensive treatment with complications and adverse reactions at the immunotherapeutic site was observed. However, the therapy was efficient in reducing the lesion, improving the infections condition of the skin and subcutaneous region.

Seroprevalence of anti--Pythium insidiosum antibodies in the Thai population.

Pythiosis is a life-threatening disease of humans and other animals in tropical and subtropical countries. The causative agent is Pythium insidiosum. Diagnosis of pythiosis can be missed due to the lack of awareness in the medical community. Treatment of the disease is difficult and challenging. Most pythiosis patients end up losing an infected organ (i.e., eye or leg), and many die from uncontrolled infection. In 2006, the largest series of human cases of pythiosis (∼100) was reported from Thailand, highlighting the nationwide distribution of this high morbidity and mortality disease. The global distribution of P. insidiosum is demonstrated by its detection in several regions around the world. Epidemiological studies of exposure to the pathogen in the general population are lacking. Here we used a combination of two established diagnostic tools (i.e., ELISA and Western blot) to explore the seroprevalence of anti-P. insidiosum antibodies in 2641 individuals, aged ≥ 15 years, sampled from Thailand. Four individuals were identified with anti-P. insidiosum antibodies in their sera, thus providing a statistically-estimated prevalence of ∼7 in 10000 or ∼32000 in the entire Thai population. The detection of the anti-P. insidiosum antibodies in healthy people with no history of pythiosis suggests that subclinical infections can occur. Taking into account the seroprevalence of anti-P. insidiosum antibodies, the global distribution of the organism, the nationwide distribution of patients, and the high morbidity and mortality of the disease, awareness of pythiosis should be raised as a public health concern in Thailand and other countries.

A CASE OF PYTHIOSIS IN A DONKEY

A case of crater-shaped granulomatous ulcer was observed in skin covering knee joint of right forelimb in 8 years old male donkey referred to Mansoura veterinary teaching hospital. Clinical examination of the lesion showed necrotic tissue with tumor appearance, abundant fibrinous-bloody exudation and yellowish-white caseous material (kunkers). Mycological isolation revealed white to off-white colonies at 37°C but not at 25°C. The colonies did not present aerial mycelium, and the mycelial growth penetrated the medium in all cultures. Histopathologically, the lesion with the hematoxylin-eosin (H&E) stain showed severe pyogranulomatous dermatitis, with abundant eosinophilic and neutrophilic inflammatory infiltrate and poorly stained thin septated hyphae. Immunohistochemistry showed positively stained hyphae inside the lesion using rabbit polyclonal antibody. The definitive diagnosis of the disease was based on the clinical features, mycological isolation, histopathological findings and immunohistochemical staining. This report described a case of pythiosis in a donkey.

Pythiosis in dogs in the semiarid region of Northeast Brazil

ABSTRACT: We describe the epidemiological, clinical and pathological features of five cases of pythiosis in dogs in northeast semiarid. The disease occurred in dogs with age between one and three years, females and males of different breeds. The dogs were created in urban areas, but were occasionally taken to the countryside and then had contact with wetlands. The main clinical signs were weight loss, vomiting, diarrhea and tenesmus. Macroscopically there were intestinal wall thickening with irregular firm masses with yellowish granular areas interspersed with a whitish tissue, involving the duodenum, colon and rectum, extending to the lymph nodes and pancreas, and the vagina and liver. In the skin there were areas of alopecia and irregular ulcerations, some containing small cavitations with serosanguineous secretion. Microscopically there were pyogranulomatous inflammation and in one case also there were eosinophilic necrosis associated with negative images tubuliformes by hematoxylin and eosin, strongly stained by GMS and weakly by PAS. Hyphae were strongly marked by immunohistochemistry with polyclonal anti-Pythium insidiosum. The disease occurs sporadically in dogs in the semiarid Northeast, however should be included in the differential diagnosis of chronic diseases and proliferative aspect of the gastrointestinal system, and front skin lesions of difficult treatment.

Pythiosis in sheep from Paraná, southern Brazil

Abstract: This paper reports pythiosis in a sheep from southwestern Paraná, Brazil, confirmed by indirect ELISA (Enzime-Linked Immunosorbent Assay) and immunohistochemistry, as well as it describes the macro and microscopic injuries, in order to understand the pathogenicity. A 4-year-old ewe from a flock of 30 Santa Inês sheep, raised semi-extensively with access to a weir, showed cachexia, bilateral enlargement in nasal region, a serous and bloody secretion with a fetid odor from its nose and swollen submandibular and retropharyngeal lymph nodes. Blood collection was performed trough jugular vein puncture in order to make complete blood cell count (CBC) and to obtain serum for the subsequent serological examination. As the hematological counts were within the normal range for sheep, the animal was euthanized and submitted to necropsy. Indirect ELISA resulted positive for pythiosis. Necropsy revealed necrosis of the hard palate with a diameter of 3.5cm and extending up to the nasal cavity, forming a fistula. Submandibular and retropharyngeal lymph nodes were enlarged and edematous on section. Microscopic findings for submandibular and retropharyngeal lymph nodes consisted in moderate infiltration of eosinophils mainly in the subcapsular sinus, characterizing reactive eosinophilic lymphadenitis. The nasal cavity revealed rhinitis and oral cavity stomatitis with necro-eosinophilic and pronounced multifocal granulomatous infiltration and presence of hyphae. Hyphae found in palate and nasal cavity were positive for Pythium insidiosum by Grocott's method and immunohistochemistry, the last one considered to be confirmatory for the pathogen diagnostic. This report has an important epidemiological aspect, as it is the first case of pythiosis in sheep confirmed by serology in South Brazil and an alert of possible infection by the pathogen in floodplains.

Aspectos epidemiológicos da conidiobolomicose em ovinos na região semiárida do Nordeste do Brasil

Com o objetivo de determinar aspectos epidemiológicos da conidiobolomicose dos ovinos, foi realizado um estudo caso-controle em 27 propriedades (16 com casos e 11 controles) nos estados da Paraíba e do Rio Grande do Norte. Das 16 propriedades com casos, em nove (56,3%), ocorreu apenas um foco e em sete (43,8%) aconteceram dois, totalizando 23 focos no período do estudo. Em 20 focos, foi diagnosticada somente conidiobolomicose e, em três, além de casos de conidiobolomicose, ocorreram casos de pitiose rinofacial. Nos focos de conidiobolomicose, a morbidade variou de 0,7% a 73,3% e a letalidade foi de 100%. Treze focos (56,5%) aconteceram no período chuvoso (janeiro a maio), seis (26,1%) ocorreram no período seco (junho a dezembro) e, em quatro, não foi determinada a época de ocorrência. Em todas as propriedades com casos, os animais tinham acesso a açudes, durante todo o ano ou por períodos de 2-8 meses. Na análise univariada dos fatores de risco referentes aos focos de conidiobolomicose, as variáveis associadas foram: pastejo dos animais às margens dos açudes; período de pastejo às margens dos açudes; presença de matéria vegetal constituída por plantas aquáticas; pressão de pastejo; e raça, afetando predominantemente a raça Santa Inês. Conclui-se que a associação de fatores como pastejo constante em áreas úmidas com matéria vegetal decomposta e solo rico em matéria orgânica expõe os animais à infecção por Conidiobolus spp. e predispõe à ocorrência de focos. A implantação de pastagens para corte, nas margens dos açudes, pode ser uma medida eficaz de controle da conidiobolomicose

Epidemiologia da pitiose equina na Região Sul do Rio Grande do Sul

Foi realizado um levantamento dos casos de pitiose equina recebidos no Laboratório Regional de Diagnóstico da Faculdade de Veterinária da Universidade Federal de Pelotas, no período de janeiro de 1979 a julho de 2011, com o objetivo de determinar as condições epidemiológicas em que a doença ocorre na região sul do Rio Grande do Sul. Nesse período foram recebidos 1888 materiais de equinos, dos quais, 435 eram provenientes do sistema tegumentar e 63 (14,5%) corresponderam à pitiose. Os animais afetados eram de ambos os sexos com idades variando entre oito meses e 22 anos. A raça mais frequentemente afetada foi a Crioula. A maioria dos casos de pitiose foi encaminhada ao laboratório entre março e junho. A evolução das lesões de pitiose variou de duas semanas até um ano. Os municípios com maior número de casos de pitiose foram Pelotas (22/63) Santa Vitória do Palmar (15/63) e Rio Grande (8/63). Foi observado que na maioria dos casos, no mês provável de infecção a temperatura máxima foi superior ou próxima a 30°C em pelo menos um dia. A observação de casos em épocas mais frias do ano pode ser devido ao fato da temperatura de águas estagnadas ser mais elevada que a temperatura ambiental o que permite o desenvolvimento das estruturas infectantes de Pythium insidiosum.

A Comparative Study of the Histopathology and Immunohistochemistry of Pythiosis in Horses, Dogs and Cattle

Twenty-one cases of pythiosis in horses (n = 10), dogs (n = 9) and cattle (n = 2) were investigated. The aetiology in all cases was confirmed by immunohistochemistry. Data related to the clinical course and outcome and localization of the lesions were obtained from pathology reports. The equine lesions consisted of fibrotic tissue with multiple, often coalescing, areas of immature granulation tissue encircling eosinophilic cores. Affected dogs had gastrointestinal and/or cutaneous lesions with either or both of a granulomatous/pyogranulomatous or necrotizing eosinophilic inflammatory reaction. In cattle, cutaneous lesions were characterized by multifocal to coalescing granulomas with surrounding fibrosis. The number of intralesional hyphae, the distribution of hyphae, the presence of angioinvasion and the nature of the local inflammatory reactions were associated with the different types of lesions observed.

Doenças da pele em caprinos e ovinos no semi-árido brasileiro

Foi realizado um estudo das doenças de pele diagnosticadas em ovinos e caprinos, no semi-árido dos Estados da Paraíba, Pernambuco e Rio Grande do Norte. De janeiro de 2000 a novembro de 2006 foram registrados no Hospital Veterinário da Universidade Federal de Campina Grande, em Patos, Paraíba, 656 diagnósticos em caprinos e 324 em ovinos, além do estudo de espécimes de necropsia ou biópsia da pele de 31 em caprinos e 45 em ovinos enviados para exame histológico. Dos casos atendidos 80 (8,16%) apresentavam alterações na pele, destes 35 ocorreram em caprinos (5,33% do total de casos diagnosticados nesta espécie) e 45 em ovinos (13,88% dos casos diagnosticados nesta espécie). Das doenças de pele, a mais freqüente foi a miíase (10 casos em caprinos e 7 em ovinos) seguida do ectima contagioso (8 casos em caprinos e 2 em ovinos), carcinoma epidermoide (4 casos em caprinos e 5 em ovinos), dermatofilose (8 casos em ovinos), dermatite alérgica (1 caso em ovino e 1 em caprino). Além disso, foram diagnosticados dois casos de pitiose em ovinos, dois casos de epidermólise bolhosa em caprinos, um caso de intoxicação por Brachiaria brizantha (fotossensibilização) e outro de intoxicação por Leucaena leucocephala (alopecia) em ovinos e um caso de papilomatose, um de pênfigo foliáceo, um de prototecose e um de rabdomiossarcoma em caprinos. Em 4 casos em ovinos e 19 em caprinos não foi realizado diagnóstico etiológico da doença. A informação gerada sobre a ocorrência e epidemiologia das doenças de pele permite estabelecer medidas adequadas de controle.

Human Pythiosis, Brazil

Pythiosis, caused by Pythium insidiosum, occurs in humans and animals and is acquired from aquatic environments that harbor the emerging pathogen. Diagnosis is difficult because clinical and histopathologic features are not pathognomonic. We report the first human case of pythiosis from Brazil, diagnosed by using culture and rDNA sequencing.

Pythiosis in Africa

We report the first case of pythiosis from Africa in an 8-month-old dog with a chronic and ulcerative cutaneous lesion. The etiologic agent belonged to the genus Pythium. Phylogenetic analysis placed the isolate in a sister group to the other P. insidiosum strains. However, the isolate may belong to a new Pythium species.