A historical review of the techniques of recovery of parasites for their detection in human stools

Abstract Since the early 20th century, the detection of intestinal parasites has improved with the development of several techniques for parasitic structures recovery and identification, which differ in sensitivity, specificity, practicality, cost, and infrastructure demand. This study aims to review, in chronological order, the stool examination techniques and discuss their advantages, limitations, and perspectives, and to provide professionals and specialists in this field with data that lays a foundation for critical analysis on the use of such procedures. The concentration procedures that constitute the main techniques applied in routine research and in parasitological kits are a) spontaneous sedimentation; b) centrifugation-sedimentation with formalin-ethyl acetate; and c) flotation with zinc sulfate solution. While selecting a technique, one should consider the purpose of its application and the technical-operational, biological, and physicochemical factors inherent in the procedures used in stool processing, which may restrict its use. These intrinsic limitations may have undergone procedural changes driven by scientific and technological development and by development of alternative methods, which now contribute to the improvement of diagnostic accuracy.

Spatial and seroepidemiology of canine visceral leishmaniasis in an endemic Southeast Brazilian area

Abstract INTRODUCTION: Canine visceral leishmaniasis (CVL) is a public health problem, and its prevalence is associated with the coexistence of vectors and reservoirs. CVL is a protozoonosis caused by Leishmania infantum that is endemic in the southeast region of Brazil. Thus, vector and canine reservoir control strategies are needed to reduce its burden. This study aimed to verify the CVL seroprevalence and epidemiology in a municipality in Southeast Brazil to initiate disease control strategies. METHODS: A total of 833 dogs were subjected to Dual Path Platform (DPP) testing and enzyme-linked immunosorbent assays. For seropositive dogs, epidemiological aspects were investigated using a questionnaire and a global position system. The data were submitted to simple logistic regression, kernel estimation, and Bernoulli spatial scan statistical analysis. RESULTS: The overall CVL-confirmed seroprevalence was 16.08%. The 28.93% in the DPP screening test was associated with dogs maintained in backyards with trees, shade, animal and/or bird feces, and contact with other dogs and cats, with sick dogs showing the highest chances of infection (odds ratio, 2.6; 95% confidence interval, 2.38-1.98), especially in residences with elderly people. A spatial analysis identified two hotspot regions and detected two clusters in the study area. CONCLUSIONS: Our results demonstrated that residences with elderly people and the presence of trees, shade, feces, and pet dogs and cats increased an individual's risk of developing CVL. The major regions where preventive strategies for leishmaniasis were to be initiated in the endemic area were identified in two clusters.

An outbreak of caprine toxoplasmosis - investigation and case report / Surto de toxoplasmose caprina - investigação e relato de caso

ABSTRACT: The present study aimed to investigate an abortion outbreak in a dairy goat herd in the municipality of Arapoti, Parana, Brazil. At the beginning of the outbreak, blood samples were collected from 33 goats with clinical signs; later, of the whole goat herd, two cats and two dogs. Milk samples were collected from 78 lactating goats. Four environmental soil samples and four samples of feed residue from goat feeders were collected too. Immunofluorescence antibody test (IFA) was used for serodiagnosis, the molecular analysis was conducted by means of the polymerase chain reaction (PCR), for the isolation of the etiological agent the bioassay was used. The results of the IFA revealed that 76.53% (137/179) of the goats, two dogs and two cats were seropositive for Toxoplasma gondii. Bioassay revealed one buffy coat and two milk sample having viable T. gondii. In the PCR, 11 whole blood samples, eight milk, three feeder troughs, and all soil samples were positive. The findings of the present study confirmed an outbreak caused by environmental contamination (of soil and feed) with T. gondii oocysts that could have been shed by kittens that lived on the farm and had access to the stock of goat food, facilitating this contamination, which reinforces the need for veterinary assistance and good management practices on farms.

RESUMO: O presente estudo teve como objetivo investigar um surto de aborto em um rebanho de cabras leiteiras no município de Arapoti, Paraná, Brasil. No início do surto, foram coletadas amostras de sangue de 33 cabras com sinais clínicos; mais tarde, de todo o rebanho caprino, dois gatos e dois cachorros. Foram obtidas amostras de leite das 78 cabras em lactação. Quatro amostras ambientais de solo e quatro de resíduos de comedouro também foram coletadas. O teste de imunofluorescência (IFI) foi utilizado para o sorodiagnóstico, a análise molecular foi conduzida por meio da reação em cadeia da polimerase (PCR), para isolamento do agente etiológico utilizou-se o bioensaio. Os resultados da IFI revelaram que 76,53% (137/179) das cabras, todos os cães e gatos eram soropositivos para Toxoplasma gondii. O bioensaio revelou uma amostra de camada leucocitária e duas de leite contaminadas com T. gondii viável. Na PCR, 11 amostras de sangue total, oito de leite, três resíduos alimentares e todas as amostras de solo foram positivas. Os resultados do presente estudo confirmaram um surto causado por contaminação ambiental (de solo e alimentos) com oocistos de T. gondii que, provavelmente, foram eliminados por gatos que permaneceram na fazenda e tinham acesso ao estoque de alimento dos caprinos, reforçando a necessidade de assistência técnica veterinária e boas práticas de manejo.

Abordagem da saúde única na ocorrência de enteroparasitas em humanos de área urbana no norte do Paraná / Single health approach in the occurrence of enteroparasites in humans in the urban area in northern Paraná / Enfoque de la salud única en ocurrencia de enteroparásitos en humanos de la zona urbana en el norte de Paraná

As enteroparasitoses causadas por helmintos e protozoários infectam humanos e animais no mundo todo, e sua prevalência está relacionada à falta de hábitos de higiene pessoal em consequência do seu ciclo oral-fecal. No Brasil, como não são doenças de notificação obrigatória, é possível que sua prevalência esteja subnotificada. Em Londrina, não existem dados sobre a prevalência dessas parasitoses na população urbana adulta, que ofereçam suporte para delinear programas de saúde preventiva na comunidade. Foram coletadas amostras de fezes de 187 humanos residentes na área urbana de Londrina para pesquisa de enteroparasitas. Dados epidemiológicos foram coletados por meio de um questionário epidemiológico aplicado a todos os participantes. As variáveis associadas ao risco foram analisadas conforme foram relatadas pelos indivíduos parasitados. Foram discutidos: gênero, idade, renda familiar mensal, lavagem das mãos antes da alimentação e após utilizar o banheiro, água de consumo, ocorrência de diarreia nos últimos sete dias, abastecimento de água e rede de esgoto. Foram detectados ovos ou cistos de parasitas em 8/187 (4,27%) amostras investigadas. A ocorrência do protozoário Giardia spp. foi verificada em 7/187 (3,74%) amostras e o helminto Enterobius vermiculares em 1/187 (0,53%). Devido ao ciclo destes parasitas envolver a saúde humana, animal e do ambiente, é sugerido que a ocorrência das enteroparasitoses reduza por meio da abordagem de Saúde Única na área urbana de Londrina, PR.

Intestinal parasitic infections are caused by helminthes and protozoa infecting humans and animals worldwide. Its prevalence is related to lack of personal hygiene habits due to its oral-fecal cycle. In Brazil, they do not require compulsory notification and, therefore, it is possible that the prevalence is underreported. In Londrina, there are no data on the prevalence of these parasites in the adult urban population to support the designing of preventive health programs in the community. Stool samples were collected from 187 human residents in the urban area of Londrina in order to research for enteroparasites. Parasite eggs or cysts were detected in 8/187 (4.27%) samples investigated. The occurrence of Giardia spp. was seen in 7/187 (3.74%) samples, while Enterobius vermicularis was observed in 1/187 (0.53%) sample. Epidemiological data were collected using an epidemiological questionnaire applied to all participants. The variables associated with the risk were analyzed and reported by infected individuals, such as: gender, age, family income, washing hands before eating and after using the bathroom, water consumption, occurrence of diarrhea in the past seven days, water supply and sewage system. Since the parasite cycle involves human, animal and environmental health, it is suggested that the occurrence of intestinal parasites be reduce through the Single Health approach in the urban area of Londrina, PR.

Las enteroparasitosis causadas por helmintos y protozoarios infectan humanos y animales en todo el mundo, y su prevalencia está relacionada con la falta de hábitos de higiene personal, como resultado de su ciclo fecal-oral. En Brasil, no son enfermedades de declaración obligatoria, es posible que su prevalencia no se denuncie. En Londrina, no hay datos sobre la prevalencia de esos parásitos en la población adulta urbana, que apoyen el diseño de programas preventivos de salud en la comunidad. Se recogieron muestras de heces de 187 residentes humanos en el área urbana de Londrina para investigación de enteroparásitos. Datos epidemiológicos se han recogido mediante un cuestionario epidemiológico administrado a todos los participantes. Las variables asociadas al riesgo se analizaron conforme relatado por los individuos infectados. Se discutieron: género, edad, renta familiar mensual, lavarse las manos antes de comer y después de ir al baño, agua de consumo, la aparición de diarrea en los últimos siete días, el suministro de agua y alcantarillado. Se ha detectado huevos o quistes de parásitos en 8/187 (4,27%) muestras investigadas. La aparición del protozoário Giardia spp. se observó en 7/187 (3,74%) muestras y el helminto Enterobius vermicularis en 1/187 (0,53%). Debido al ciclo de estos parásitos involucrar la salud humana, animal y el medio ambiente, se sugiere que la aparición de enteroparasitosis se reduzca a través del enfoque de Salud Única en la zona urbana de Londrina, PR.

Occurrence of Ehrlichia canis and Anaplasma platys in household dogs from northern Parana / Ocorrência de Ehrlichia canis e Anaplasma platys em cães domiciliados da região norte do Paraná

Canine monocytic ehrlichiosis caused primarily by Ehrlichia canis and canine thrombocytic anaplasmosis induced by Anaplasma platys are important emerging zoonotic tick-borne diseases of dogs. There is evidence that these pathogens can also affect humans. This study evaluated the presence of E. canis and A. platys in blood samples collected from 256 domiciled dogs in the municipality of Jataizinho, located in north region of the State of Parana, Brazil, by PCR assay. The occurrence of E. canis and A. platys was 16.4% (42/256) and 19.4% (49/256), respectively; while 5.47% (14/256) of the dogs evaluated were co-infected by these two organisms. The presence of E. canis and A. platys was not significantly associated with the variables evaluated (sex, age, outdoor access, and presence of ticks during blood collection). Infection of dogs by E. canis was associated with anemia and thrombocytopenia, while infection induced by A. platys was related only to thrombocytopenia. Canine monocytic ehrlichiosis and canine thrombocytic anaplasmosis should be included in the differential diagnoses when these hematological alterations are observed during routine laboratory evaluation of dogs.(AU)

Erliquiose monocítica canina, causada principalmente por Ehrlichia canis, e anaplasmose trombocítica canina, devida a infecção com Anaplasma platys, são importantes doenças transmitidas por carrapatos que acometem os cães, com evidências que podem também acometer o homem. O presente estudo avaliou a ocorrência desses agentes em amostras de sangue de 256 cães domiciliados na cidade de Jataizinho, na região Norte do Paraná, Brasil, utilizando a técnica da Reação em Cadeia da Polimerase (PCR). A ocorrência de E. canis e A. platys foi de 16,4% (42/256) e 19,4% (49/256), respectivamente, com 5,47% (14/256) dos animais apresentando coinfecção. Não foi observada associação significativa com as variáveis sexo, idade, acesso à rua e presença de carrapatos no momento da coleta de sangue. A infecção por E. canis teve relação com anemia e com trombocitopenia, enquanto a infecção por A. platys apresentou relação apenas com trombocitopenia. Com base nos resultados obtidos, reforçou-se a necessidade de que erliquiose e anaplasmose canina devem estar entre os diagnósticos diferenciais, quando da detecção de anemia e trombocitopenia em exames laboratoriais.(AU)