Needs assessment of a pythiosis continuing professional development program.

BACKGROUND: Pythiosis is a rare disease with high mortality, with over 94% of cases reported from Thailand and India. Prompt diagnosis and surgery improves patient outcomes. Therefore, continuing professional development (CPD) is essential for early recognition. However, a needs assessment related to a pythiosis CPD program has not been performed. OBJECTIVES: We conducted a needs assessment to develop a pythiosis CPD program. PATIENTS/METHODS: We conducted a survey study with 267 King Chulalongkorn Memorial Hospital residents (141 internal medicine (IM) residents and 126 surgery residents). A 30-item survey consisting of a knowledge assessment, demographic section, and an attitudes portion was distributed both electronically and via paper. The data was analyzed with descriptive and inferential statistics. RESULTS: Sixty-seven percent completed the survey (110/141 IM residents, 70/126 surgery residents). The mean score [95% confidence interval] on the knowledge assessment was 41.67% [39.64%-43.69%] across all objectives. The three domains with the highest scores were pythiosis risk factors (67.22% correct), microbiologic characteristics (50.83%), and radiographic interpretation (50.56%). The three domains with the lowest scores were laboratory investigation (15.00%), epidemiology (29.17%), and symptomatology (30.83%). Most participants noted that the program should be online with both synchronous and asynchronous sessions, with a preferred length of 60-90 minutes per session. CONCLUSION: The pythiosis CPD program should emphasize education regarding symptomatology, laboratory investigation, and epidemiology, all of which are critical for the early detection of pythiosis to decrease mortality from this devastating disease. Most respondents felt this program was necessary and should be implemented in a virtual blended format.

Epidemiology of horse pythiosis in the Pantanal of Mato Grosso: Exploring the host-parasite-vector relationship.

Horse pythiosis is considered an endemic disease in the Brazilian Pantanal region, causing devastating health and economic losses. This study aimed to enhance the understanding of pythiosis epidemiology, map the distribution of horse body lesions, and investigate the correlation between these lesions and warm body surface areas, potentially implicating hematophagous vectors in the disease's transmission. A prospective study was conducted on equids in the Pantanal Mato-grossense and adjacent areas from 2012 to 2022, with 112 horses and three mules diagnosed with pythiosis. Clinical and epidemiological data, lesions' photographic records, and healthy equids' thermal imaging were collected. Most pythiosis cases occurred between January and March, correlating with regional flood cycles. Most lesions were found on limbs and the ventral abdomen, with dark-colored horses exhibiting a higher frequency of lesions. Interestingly, the thermal mapping revealed that warm areas on a healthy horse's body overlapped significantly with lesion distribution - blood-sucking insects also prefer these areas. The results suggest that pythiosis lesions in horses correlate with warmer areas of the animal body, reinforcing the hypothesis of vector involvement in disease transmission. This study underscores the need for further observational research to fully understand the complex epidemiological dynamics of pythiosis in horses.

Cutaneous Pythiosis in 2 Dogs, Italy.

We report cutaneous pythiosis in 2 dogs in Italy that had recurrent exposure to the same freshwater habitat. Phylogenetic analysis placed the isolates within Pythium insidiosum complex cluster IV, corresponding to P. periculosum. In Italy, pythiosis should be considered in differential diagnoses by human and veterinary health professionals.

A Retrospective Study of Pythiosis in Domestic Animals in Northeastern Brazil.

Pythiosis is an endemic disease in northeastern Brazil and we now report the epidemiological, clinical and pathological findings in a retrospective study of naturally occurring cases in domestic animals. From January 1985 to December 2020, the Laboratory of Animal Pathology of the Federal University of Campina Grande examined 13,542 tissue samples from necropsies and biopsies. Among these samples, 306 were diagnosed as pythiosis: 195 cases in horses, 75 in sheep, 19 in dogs, six in mules, four in cattle, three in cats, two in goats, one in a donkey and one in an ostrich. Affected equids had lesions in the skin, mammary glands and nasal cavities. Affected sheep had cutaneous, nasal and digestive lesions while cattle and goats had cutaneous lesions. Carnivores developed lesions, mainly in the alimentary tract, of sufficient severity to cause death or result in euthanasia. The single affected bird had lesions in the alimentary tract and surgical excision resulted in remission. The disease had a long and life-threatening clinical course in most affected species but resolved spontaneously in cattle. Clinical signs were directly related to the location of the lesions, which were invariably characterized by chronic inflammation associated with intralesional hyphae. Veterinary clinicians and pathologists should be familiar with the clinicopathological features of pythiosis and the wide range of susceptible animal species.

Role of Immunotherapy in Pythium insidiosum Keratitis.

Pythium keratitis is a potentially devastating ocular condition. Incidence of Pythium keratitis has been reported in tropical and subtropical areas. In previous reports, there were no effective or standard treatments, and combinations of medication, immunotherapy, and surgery were proposed. Pythium insidiosum antigen immunotherapy (PIAI) showed an acceptable safety profile, but its efficacy is questionable in Pythium keratitis. This retrospective review included 10 eyes from 10 patients. All cases were confirmed diagnosis of P. insidiosum keratitis by culture and/or polymerase chain reaction. Three doses of PIAI were injected at 2-week intervals in all patients. The infiltration diameter ranged from 5.2 mm to total corneal involvement, and eight cases (80%) had hypopyon. Therapeutic penetrating keratoplasty (TPK) or scleral graft were undertaken in nine cases. Enucleation was done in one case on the first visit. A second TPK was undertaken in three cases, and two globes were saved. Two cases in the globe salvage group received voriconazole via eyedrops and intracameral injection. No case received either linezolid or azithromycin. Three of nine eye globes (33.33%) were saved. PIAI did not show efficacy in the treatment of Pythium keratitis. Radical surgery including resurgery in recurrence is an approved effective treatment. The recently reported medications may offer supportive management.

Pythium insidiosum keratitis - A review.

Pythium insidiosum is an oomycete and is also called "parafungus" as it closely mimics fungal keratitis. The last decade saw an unprecedented surge in Pythium keratitis cases, especially from Asia and India, probably due to growing research on the microorganism and improved diagnostic and treatment modalities. The clinical features such as subepithelial infiltrate, cotton wool-like fluffy stromal infiltrate, satellite lesions, corneal perforation, endoexudates, and anterior chamber hypopyon closely resemble fungus. The classical clinical features of Pythium that distinguish it from other microorganisms are reticular dots, tentacular projections, peripheral furrowing, and early limbal spread, which require a high index of clinical suspicion. Pythium also exhibits morphological and microbiological resemblance to fungus on routine smearing, revealing perpendicular or obtuse septate or aseptate branching hyphae. Culture on blood agar or any other nutritional agar is the gold standard for diagnosis. It grows as cream-colored white colonies with zoospores formation, further confirmed using the leaf incarnation method. Due to limited laboratory diagnostic modalities and delayed growth on culture, there was a recent shift toward various molecular diagnostic modalities such as polymerase chain reaction, confocal microscopy, ELISA, and immunodiffusion. As corneal scraping (10% KOH, Gram) reveals fungal hyphae, antifungals are started before the culture results are available. Recent in vitro molecular studies have suggested antibacterials as the first-line drugs in the form of 0.2% linezolid and 1% azithromycin. Early therapeutic keratoplasty is warranted in nonresolving cases. This review aims to describe the epidemiology, clinical features, laboratory and molecular diagnosis, and treatment of Pythium insidiosum keratitis.

Outbreak of equine pythiosis in a southeastern region of Brazil: Environmental isolation and phylogeny.

Pythiosis is a disease caused by the oomycete Pythium insidiosum, mainly reported in equines, dogs and humans and directly transmitted through contaminant zoospores in aquatic environments. We report the first outbreak of equine pythiosis in five equines. Wound samples were submitted for diagnostic testing including mycological culture and nested PCR. Treatment approaches consisted of conventional and alternative therapies. Microbiological analyses were performed using water samples from the riverbanks close to where the animals had grazed. All animals were positive for P. insidiosum cultures, and two animals responded successfully to alternative therapy (ozone therapy). After culture and molecular analysis of environmental samples, the presence of P. insidiosum in one section of the Tietê River was confirmed through a 99% sequence identity. Phylogenetic analyses using the cytochrome oxidase II gene showed that the animal isolates clustered in clade I and the environmental isolates clustered in clade III. Although the environmental and wound isolates belonged to different genetic clades, we concluded that the Tietê River is an important source of infection by P. insidiosum and that research concerning environmental isolation of P. insidiosum from rivers and lakes should be strongly facilitated in Brazil.

Geographic distribution of Pythium insidiosum infections in the United States.

OBJECTIVE: To describe the geographic distribution of infections caused by Pythium insidiosum in dogs, horses, and other animal species in the US. ANIMALS: 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. PROCEDURES: 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). RESULTS: 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. CLINICAL RELEVANCE: 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.

Pythiosis in Equidae in Northeastern Brazil: 1985-2020.

The epidemiologic, clinical, pathologic, microbiological and immunohistochemical findings of pythiosis in equidae in northeastern Brazil are described. From January 1985 to December 2020 the Laboratory of Animal Pathology of the Federal University of Campina Grande received 1,331 tissue samples of equidae, 202 (15.17%) of which were diagnosed as pythiosis. Equidae of both sexes with ages varying from 4 months to 25 years were affected. Most animals were mixed breed (79.7%) and reared in an extensive system (73.26%). The disease occurred throughout the year but the highest incidence (70.29%) was noted after the rainy season. The clinical course was always chronic. The lesions were preferentially located on the limbs and ventral thoracoabdominal wall and characterized by nodules or tumor-like masses with ulcerations and serosanguineous discharge. The cut surface showed fistulous tracts containing kunkers. The direct examination of the kunkers and microbiological culture revealed sparsely septate and branched hyaline hyphae. Histopathology revealed a marked inflammatory infiltrate of eosinophils with multifocal well-defined areas of eosinophil necrosis and collagenolysis and intralesional negatively-stained hyphal profiles; in the donkey, a pyogranulomatous inflammatory infiltrate was noted surrounding these areas. Immunohistochemistry for Pythium insidiosum revealed strong immunolabelling of the hyphae. Pythiosis occurs endemically in equidae in northeastern Brazil, with seasonal variation in the incidence. The intralesional kunkers establishes an accurate presumptive diagnosis, but confirmation should preferably be performed through histopathology associated with immunohistochemistry, culture-based or molecular methods.

Retrospective multifactorial analysis of Pythium keratitis and review of literature.

Purpose: The aim of this work was to study the demographic profile, clinical diagnostic features, challenges in management, treatment outcomes, and ocular morbidity of microbiological culture-proven Pythium keratitis in a tertiary eye care hospital in South India. Methods: Retrospective analysis of microbiologically proven Pythium keratitis patients was performed at a tertiary eye center from October 2017 to March 2020. Demographic details, risk factors, microbiological investigations, clinical course, and visual outcomes were analyzed. Results: Thirty patients were analyzed. The mean age was 43.1±17.2 years. Most common risk factors were history of injury in 80% and exposure to dirty water in 23.3%. Visual acuity at baseline was 20/30 to perception of light (PL). The most common clinical presentation was stromal infiltrate and hypopyon in 14 (46.6%) patients each. The microbiological confirmation was based on culture on blood agar and vesicles with zoospores formation with incubated leaf carnation method. Seven (23.3%) patients improved with topical 0.2% Linezolid and topical 1% Azithromycin, 19 (63.3%) patients underwent Therapeutic keratoplasty (TPK) and 4 were lost to follow-up. Seven (23.3%) patients had graft reinfection, and 3 (10%) developed endophthalmitis. The final visual acuity was 20/20- 20/200 in 6 (20%) patients, 20/240-20/1200 in 5 (16.6%) patients, hand movement to positive perception of light in 16 patients and no perception of light (Pthisis Bulbi) in 3 (10%) patients. Conclusion: P. insidiosum keratitis is a rapidly progressive infectious keratitis with prolonged and relapsing clinical course. It usually results in irreparable vision loss in majority of the patients. Prompt diagnosis, clinical awareness, and specific treatment options are needed for successfully managing this devastating corneal disease.

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

INTRODUCTION: Pythium 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 METHODS: We 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. RESULTS: ELISA 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%). CONCLUSION: The 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.

Pythiosis in cattle in Northeastern Brazil / Pitiose em bovinos no Nordeste do Brasil

The epidemiological, clinical and pathological aspects of cutaneous pythiosis occurring in cattle from three farms in the Northeastern of Brazil are described. A biopsy of the lesions of one bovine from each farm was performed. In two cases, the affected cattle had contact with water accumulated in dams during the dry season in the semiarid region. Another case occurred in the coastal tropical region in cattle grazing around irrigation channels. Clinically, lesions were observed mainly on the skin of the thoracic and/or pelvic limbs, characterized by flat and irregular ulcerated areas or nodules of varying sizes, some with fistulous tracts penetrating deep into the subcutaneous tissue. In one case the regional lymph nodes were affected. Histologically, in all cases, pyogranulomatous dermatitis associated with negative hyphae images, in hematoxylin-eosin stained sections, were observed. In sections stained by Grocott methenamine silver, the hyphae measured 2-8μm and had irregular ramifications and rare septations. Immunohistochemistry technique demonstrated strong immunolabeling for Pythium insidiosum. Pythiosis should be included in the differential diagnosis of dermatopathies in cattle in the Northeastern of Brazil.(AU)

Descrevem-se os aspectos epidemiológicos, clínicos e patológicos da pitiose cutânea em bovinos de três propriedades do Nordeste do Brasil. Uma biópsia das lesões de um bovino de cada propriedade foi realizada. Em dois casos, os bovinos afetados tiveram acesso à água acumulada em açudes durante a estação seca da região semiárida. O outro bovino acometido estava a pastoreio próximo a canais de irrigação na região litorânea. Clinicamente, as lesões foram observadas principalmente na pele dos membros torácicos e/ou pélvicos e caracterizavam-se por áreas planas e irregulares de ulceração ou nódulos de tamanhos variados, alguns com trajetos fistulosos penetrando profundamente no tecido subcutâneo. Em um caso, os linfonodos regionais foram afetados. Histologicamente, em todos os casos, observou-se dermatite piogranulomatosa associada a imagens negativas de hifas, em secções corados por hematoxilina e eosina. Em seções coradas por metenamina de prata de Grocott, as hifas mediam 2-8μm e possuíam ramificações irregulares com raras septações. A imuno-histoquímica demonstrou forte imunomarcação para Pythium insidiosum. A pitiose deve ser incluída como diagnóstico diferencial de dermatopatias de bovinos no Nordeste do Brasil.(AU)

Equine pythiosis in the eastern wetlands of Uruguay / Pitiose equina em áreas úmidas do leste do Uruguai

Equine pythiosis is an ulcerative and granulomatous disease of the skin, caused by the oomycete Pythium insidiosum (Pythiaceae). The objective of this study was to describe seven cases of equine pythiosis that occurred from 2012 to 2017 in the eastern region of Uruguay. Six of the seven cases occurred in the eastern wetland ecosystems of the Merin basin, and the remaining case occurred in the wetland fluvial plains of the Tacuarembó River. Lesions consisted of a large, rapidly growing ulcerated tumor with abundant granulation tissue, serosanguineous secretion, and fistulous tracts containing large concretions or kunkers. The animals presented intense pruritus, claudication and loss of body condition, with death or euthanasia in extremis in six cases. The main histological lesions consisted of an eosinophilic and pyogranulomatous inflammatory process, with numerous foci of eosinophilic necrosis (kunkers), collagenolysis, and a Splendore-Hoeppli reaction. In all cases, silver coloration (Grocott) showed intralesional hyphae compatible with P. insidiosum, which was confirmed by immunohistochemistry in three cases. A horse in the terminal phase of the disease was treated with triamcinolone acetonide (50mg IM every 15 days), and fully recovered after 1 year. It is concluded that equine pythiosis is prevalent in the wetland ecosystems of eastern Uruguay and that treatment with triamcinolone is auspicious.(AU)

Pitiose é uma doença granulomatosa e ulcerativa da pele dos equinos causada pelo oomyceto Pythium insidiosum (Pythiaceae). O objetivo deste trabalho foi descrever sete casos de pitiose equina que ocorreram de 2012 a 2017 na região leste do Uruguai. Seis dos sete casos ocorreram no ecossistema de áreas pantanosas da bacia da bacia da Lagoa Mirim Merin e o restante nas planícies fluviais pantanosas do rio Tacuarembó. As lesões se caracterizaram por tumores ulcerados de crescimento rápido com abundante tecido de granulação, secreção serossanguinolenta e presença de tratos fistulosos contendo material coraloide ou kunkers. Os equinos apresentavam prurido intenso, claudicação e perda da condição corporal e seis morreram ou foram eutanasiados in extremis. As principais lesões histológicas consistiam de um processo inflamatório piogranulomatoso com numerosos focos de necrose eosinofílicos (kunkers), colagenólise e reação de Splendori-Hoepli. Em todos os casos a impregnação pela prata (Grocott) revelou a presença de hifas intralesionais compatíveis com P. insidiosum, o que foi confirmado pela imuno-histoquímica em três casos. Um equino em fase terminal da doença foi tratado com triamcinolona acetonida (50mg, IM, a cada 15 dias), recuperando-se completamente após um ano. Conclui-se que a pitiose é uma enfermidade presente em áreas úmidas na região leste do Uruguai e o tratamento com triamcinolona pode ser uma alternativa promissora.(AU)

Identification of Pythium insidiosum complex by matrix-assisted laser desorption ionization-time of flight mass spectrometry.

PURPOSE: Pythiosis is an infection of humans and other animals caused by the fungal-like pathogen Pythium insidiosum. This pathogen causes life-threatening infection in the infected hosts. Culture, histopathology, serology and molecular tools are used to diagnose its infections. Successful management of pythiosis is directly linked to an early diagnosis. Thus, a rapid identification of putative cultures developing submerged sparsely septate hyphae is of extreme importance. However, few laboratories are familiar with the culture identification of this unique pathogen and its differential diagnosis with similar filamentous fungi. METHODOLOGY: We have evaluated the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) on 53 isolates of P. insidiosum collected from cases of human and animal pythiosis in the USA and around the world. To assess the specificity of the approach, 18 pathogenic and saprotrophic filamentous fungal and fungal-like microbes were also tested. RESULTS: MALDI-TOF in-house spectra correctly identified the 53 P. insidiosum isolates (score range 1.93-2.51). MALDI-TOF based identification within P. insidiosum isolates showed protein spectra variation between geographical diverse isolates. A mass spectrometry approach was able to discriminate P. insidiosum from the 18 filamentous fungal and fungal-like microbes in this study, including four Pythium spp. and Phytopythium litorale plant pathogenic species. CONCLUSION: The data showed MALDI-TOF could be used for the accurate and rapid culture identification of P. insidiosum in the clinical laboratory.

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.

Clinical profile, risk factors and outcome of medical, surgical and adjunct interventions in patients with Pythiuminsidiosum keratitis.

PURPOSE: To report clinical profile and compare management options for Pythium keratitis. METHOD: Retrospective interventional study of 46 patients diagnosed as Pythium keratitis by PCR DNA sequencing from January 2014 to July 2017. Interventions were categorised into medical management (MM) (topical azithromycin and linezolid with oral azithromycin at presentation), surgery (S) (therapeutic penetrating keratoplasty, TPK), surgical adjunct (SA) (cryotherapy±alcohol with TPK) and medical adjunct (MA) (MM after TPK). RESULTS: Primary treatment included MM (1 eye), SA (3 eyes) and S (42 eyes). Recurrence occurred in 27/43 eyes (MM+S group). Second surgery (S) was required in 11 eyes (TPK-2), with additional procedures (SA) in 10 eyes and evisceration in five eyes. 8/43 eyes received MA after TPK-1. One eye required TPK-3. Recurrence occured in all eyes that received MA (100%) and in 28 of 54 TPKs (51.8%) (TPK 1+2+3) in 42 eyes. Recurrence was noted in 1/14 (7.1%) that underwent SA. CONCLUSION: The currently available and recommended treatment for Pythium keratitis is surgical by means of a TPK and in worse cases evisceration. In our study, MM/MA measures showed no benefit with recurrence or worsening of infection requiring resurgery. Almost 50% of TPKs had a recurrence requiring resurgery. However, adjunctive procedures during TPK appear to have additional benefit with low risk of recurrence and could be included as routine care.

Pythium keratitis in South India: Incidence, clinical profile, management, and treatment recommendation.

PURPOSE: To study the demographic profile, clinical features, treatment outcome, and ocular morbidity of microbiologically proven Pythium keratitis in South India. METHODS: A retrospective analysis of clinical records of microbiologically proven Pythium keratitis at a tertiary eye care referral center in South India from January 2016 to November 2017 was performed. Demographic details, predisposing risk factors, microbiological investigations, clinical course, and visual outcome were analyzed. RESULTS: Seventy-one patients with microbiologically proven Pythium keratitis were identified. The mean age was 44(±18.2) years with an increase in male preponderance and 50% were farmers. Duration of delay at time of presentation to the hospital was a mean of 14(±7.2) days. The visual acuity at baseline ranged from 6/6 to no light perception (median 2.1 logMAR). A combination of 5% natamycin and 1% voriconazole was given to 42% patients, and natamycin alone was given to 39.4% patients. 1% itraconazole eye drops alone was initiated in 7 (10%) patients and 3 among this group responded. Therapeutic keratoplasty (TPK) was performed in 48 (67.6%) patients. None of the primary grafts remained clear after a period of 1 month. Twenty-six eyes (54.2%) had graft reinfection and all these eyes either developed anterior staphyloma (4) or were eviscerated (3) and 13 eyes became phthisical. The remaining 22 patients who had TPK resulted in failed graft. Among these, re-grafts were performed in 6 patients, of which 5 were doing well at the last follow-up. CONCLUSION: We report a large series of patients with Pythium keratitis. Promoting early and differential diagnosis, awareness of clinicians and specific treatment options are needed for this devastating corneal disease.

Potential distribution of Pythium insidiosum in Rio Grande do Sul, Brazil, and projections to neighbour countries.

Pythium insidiosum is a widespread pathogen that causes pythiosis, a disease with severe health consequences in horses and humans worldwide. Latin America hosts one of the largest, but scattered, horse herds, making it critical to identify areas at high risk of pythiosis transmission to help guide surveillance in areas with disease transmission risk. We utilized ecological niche modelling and epidemiological data to reconstruct the ecological conditions for pathogen circulation to identify areas with potential risk of pythiosis in Brazil and Uruguay. We surveyed 338 horse farm locations in southern Brazil and reconstructed the landscape conditions where the disease is endemic, based on the association between high-resolution satellite imagery and P. insidiosum serology. The final model was projected to the entire Brazil-Uruguay border region to predict areas at risk of disease transmission. We detected 66 seropositive farms and risk of infection in areas with low vegetation and low temperatures. There was a significant difference between seropositive and seronegative locations, mainly during the summer, suggesting that P. insidiosum circulates under specific landscape conditions. Areas that were unsuitable for P. insidiosum circulation were clustered in the central, north-eastern, and north-western regions of the study area. Our findings suggest that P. insidiosum is a generalist pathogen that has the potential to circulate across broad areas in Uruguay and Rio Grande do Sul in Brazil. The risk maps generated may help stakeholders with disease prevention, as well as highlight pythiosis as a potential transboundary disease with economic and public health importance.

Epidemiologia de micoses, pitiose e micotoxicoses em equinos no sudeste do Rio Grande do Sul / Epidemiology of mycoses, pitiosis and micotoxicosis in horses in southeastern Rio Grande do Sul, Brazil

Descrevem-se os aspectos epidemiológicos das doenças causadas por fungos e oomicetos na população de equinos na região sudeste do Rio Grande do Sul, estabelecendo as taxas epidemiológicas, suas causas e sua importância sanitária na região. Foi realizada a epidemiologia descritiva por meio do cálculo da incidência das doenças encontradas ao longo dos anos e verificada a existência de associação entre a ocorrência dessas enfermidades e o sexo, a raça e a estação do ano. Entre os anos de 1978 e 2014 a pitiose teve prevalência de 49,71% (86/173), as micotoxicoses 30,05% (52/173), sendo 45 casos de leucoencefalomalácia e sete de ergotismo. As micoses tiveram prevalência de 19,65% (34/173), sendo as dermatofitoses as mais prevalentes com 58,82% (20/34) dos casos. As espécies de dermatófitos mais frequentemente isoladas foram Trichophyton mentagrophytes 60% (12/20), Trichophyton equinum 25% (5/20) e Microsporum gypseum, Microsporum canis e Trichophyton verrucosum ambos responsáveis por 5% (1/20) das infecções. Rinosporidiose foi diagnosticada em 35,29% (12/34) dos casos. Micoses uterinas causadas por Candida albicans e Cryptococcus laurentii foram observadas em 5,88% (2/34) dos casos. Alergia por Cladosporium sp. teve um registro. De acordo com as incidências calculadas entre 1990 e 2014 a pitiose teve incidência mediana (IM) 2,98 e distância interquartil (DI) =3,82, as fêmeas tiveram chance 4,18 vezes maiores de desenvolver a doença, a enfermidade ocorre independente das estações climáticas. A leucoencefalomalácia teve IM=0,0; DI 1,00 e equinos machos tiveram 3,4 vezes mais chance de desenvolver a doença que fêmeas, no inverno a possibilidade de ocorrência dessa enfermidade foi seis vezes maior. O ergotismo teve IM = 0,00; DI = 0,000, rinosporidiose IM=0,00; DI=0,088 e dermatofitose IM=0,00; DI=0,935. A pitiose foi mais prevalente entre as doenças encontradas, podendo ser considerada endêmica na região. Considera-se que a magnitude das doenças possa ser ainda maior dentro do rebanho equino, uma vez que as doenças descritas não são de notificação obrigatória e algumas são bem conhecidas por veterinários e proprietários, que muitas vezes não fazem a confirmação laboratorial do diagnóstico.(AU)

The epidemiological aspects of diseases caused by fungi and oomycetes in horses in southeastern Rio Grande do Sul, Brazil, is described. The epidemiological rates, their causes, and health importance in the region were established. A descriptive epidemiology study was carried out in relation of potential risk factors. The impact on these diseases in the region was measured. From 1978 to 2014, pythiosis had a prevalence of 49.71% (86/173), and mycotoxicoses of 30.05% (52/173), with 45 cases of leukoencephalomalacia and 7 of ergotism. The prevalence of fungal infections was 19.65% (34/173) of cases. Dermatophytosis was the most prevalent fungal infection with 58.82% (20/34) of cases. The most isolated dermatophyte species were Trichophyton mentagrophytes 60% (12/20), Trichophyton equinum 25% (5/20) and Microsporum gypseum, Microsporum canis, and Trichophyton verrucosum, both responsible for 5% (1/20) of infections. Rhinosporidose was diagnosed in 35.29% (12/34) of cases. Uterine mycosis caused by Candida albicans and Cryptococcus laurentii was observed at 5.88% (2/34) of cases. Cladosporium sp. allergy was noted in one record. According to the incidence from 1990 to 2014, pythiosis had median incidence (MI) of 2.98 and interquartile range (DI) of 3.82. Mares were 4.18 times likely to develop the disease then males. The disease occurs in the region in every season. Leukoencephalomalacia had MI of 0.0; DI 1.00 and male horses were 3.4 times more likely than mares to develop the disease. Leukoencephalomalacia was 6 times more likely to occur during winter. Ergotism had MI of 0.00; DI of 0.000, rhinosporidiosis MI of 0.00, DI of 0.088 and ringworm MI of 0.00, and DI of 0.935. In the study pythiosis had the highest prevalence among the diseases observed, and may be considered endemic in the region. The magnitude of the diseases observed may be even greater within the equine herd, since these diseases are not of obligatory notification and some are well known by veterinarians and owners, who often do not obtain a laboratory confirmation of the diagnosis.(AU)

Clinicopathological features and outcomes of pythiosis.

OBJECTIVES: Vascular pythiosis is a life-threatening infection caused by the oomycete Pythium insidiosum. This article reports the clinical presentation, serodiagnosis, pathology, and outcomes seen at the authors' institution. METHODS: The cases of patients with proven vascular pythiosis at Ramathibodi Hospital, Mahidol University, Bangkok, Thailand from January 2006 to December 2016 were analyzed retrospectively. RESULTS: Thirteen patients were analyzed, eight of whom had underlying thalassemias. Of the remaining five patients, one had aplastic anemia, one had myelodysplasia, one had acute leukemia, one had cirrhosis, and one had alcoholism. Neutropenic patients showed a rapid clinical deterioration. Atypical presentations including carotid arteritis, aneurysm, brain abscess, and stroke occurred in the non-thalassemic patients. Serology yielded positive results in all cases, with a rapid turnaround time. Serology has the advantage of providing a presurgical diagnosis, which allows prompt surgery and clinical cure to be achieved. Pathology revealed a neutrophilic response in the acute phase and a later shift to granuloma. Immunotherapy in combination with itraconazole and terbinafine was given. The amputation rate was 77%, and disease-free surgical margins were achieved in five cases (38%). The mortality rate was 31%. CONCLUSIONS: This study highlights new aspects of pythiosis, such as the unusual host, clinical presentation, serology as a marker for rapid diagnosis, histopathology, and outcomes. Early recognition of the disease with prompt multimodality treatment may improve survival.