Occurrence of Hymenolepis diminuta: a potential helminth of zoonotic importance in murid rodents / Ocorrência de Hymenolepis diminuta: um helminto potencial de importância zoonótica em roedores murídeos

The study reveals the prevalence of a potential rodent-borne zoonotic helminth species, Hymenolepis diminuta in commensal rodents caught from irrigated and rain-fed areas of Swat, Pakistan. Three hundred and fifty rodents (269 rats and 81 mice) trapped during vegetative, flowering/fruiting and mature/harvesting stages of crops were studied from 2011-2013. Hymenolepisdiminuta eggs were identified on the basis of their shape, size, colour and markings on the surface of the egg shell and three pairs of embryonic hook-lets. Overall prevalence of H. diminuta was 3.14% (n=11/350). The highest prevalence 3.49% (n=5/143) of H. diminuta was noted at harvesting stages of the crops whereas the lowest 2.59% (n=2/77) during vegetative stage. Infection was higher in males 3.25% (n=7/215) than females 2.96% (n=4/135). Adult rodents were highly infected while no sub-adult was found infected. Infection was higher in mice 3.70% (3/81) than rats 2.69% (8/269) while no significance (p=1.0000:0.1250 to 32.00 CI). Rats and mice appears to show the most suitable reservoirs by hosting H. diminuta a zoonotic helminth. The presence of these rodents in all possible habitats can act as a main channel of transferring parasites through various habitats and can pose a hazard to humans in the area.

O estudo revela a prevalência de uma espécie potencial de helmintos zoonóticos transmitidos por roedores, Hymenolepis diminuta, em roedores comensais capturados em áreas irrigadas e alimentadas pela chuva de Swat, Paquistão. Trezentos e cinquenta roedores (269 ratos e 81 camundongos) presos durante os estágios vegetativo, floração/frutificação e maturidade/colheita das safras foram estudados de 2011-2013. Ovos de Hymenolepisdiminuta foram identificados com base em sua forma, tamanho, cor e marcações na superfície da casca do ovo e três pares de anzóis embrionários. A prevalência geral de H. diminuta foi de 3,14% (n = 11/350). A maior prevalência 3,49% (n = 5/143) de H. diminuta foi observada na fase de colheita das lavouras, enquanto a menor 2,59% (n = 2/77) durante a fase vegetativa. A infecção foi maior nos homens 3,25% (n = 7/215) do que nas mulheres 2,96% (n = 4/135). Roedores adultos foram altamente infectados, enquanto nenhum subadulto foi encontrado infectado. A infecção foi maior em camundongos 3,70% (3/81) do que em ratos 2,69% (8/269), embora sem significância (p = 1,0000: 0,1250 a 32,00 CI). Ratos e camundongos parecem mostrar os reservatórios mais adequados hospedando H. diminuta um helmintos zoonótico. A presença desses roedores em todos os habitats possíveis pode atuar como um canal principal de transferência de parasitas através de vários habitats e pode representar um perigo para os humanos na área.

Occurrence of Hymenolepis diminuta: a potential helminth of zoonotic importance in murid rodents

Abstract The study reveals the prevalence of a potential rodent-borne zoonotic helminth species, Hymenolepis diminuta in commensal rodents caught from irrigated and rain-fed areas of Swat, Pakistan. Three hundred and fifty rodents (269 rats and 81 mice) trapped during vegetative, flowering/fruiting and mature/harvesting stages of crops were studied from 2011-2013. Hymenolepisdiminuta eggs were identified on the basis of their shape, size, colour and markings on the surface of the egg shell and three pairs of embryonic hook-lets. Overall prevalence of H. diminuta was 3.14% (n=11/350). The highest prevalence 3.49% (n=5/143) of H. diminuta was noted at harvesting stages of the crops whereas the lowest 2.59% (n=2/77) during vegetative stage. Infection was higher in males 3.25% (n=7/215) than females 2.96% (n=4/135). Adult rodents were highly infected while no sub-adult was found infected. Infection was higher in mice 3.70% (3/81) than rats 2.69% (8/269) while no significance (p=1.0000:0.1250 to 32.00 CI). Rats and mice appears to show the most suitable reservoirs by hosting H. diminuta a zoonotic helminth. The presence of these rodents in all possible habitats can act as a main channel of transferring parasites through various habitats and can pose a hazard to humans in the area.

Resumo O estudo revela a prevalência de uma espécie potencial de helmintos zoonóticos transmitidos por roedores, Hymenolepis diminuta, em roedores comensais capturados em áreas irrigadas e alimentadas pela chuva de Swat, Paquistão. Trezentos e cinquenta roedores (269 ratos e 81 camundongos) presos durante os estágios vegetativo, floração/frutificação e maturidade/colheita das safras foram estudados de 2011-2013. Ovos de Hymenolepisdiminuta foram identificados com base em sua forma, tamanho, cor e marcações na superfície da casca do ovo e três pares de anzóis embrionários. A prevalência geral de H. diminuta foi de 3,14% (n = 11/350). A maior prevalência 3,49% (n = 5/143) de H. diminuta foi observada na fase de colheita das lavouras, enquanto a menor 2,59% (n = 2/77) durante a fase vegetativa. A infecção foi maior nos homens 3,25% (n = 7/215) do que nas mulheres 2,96% (n = 4/135). Roedores adultos foram altamente infectados, enquanto nenhum subadulto foi encontrado infectado. A infecção foi maior em camundongos 3,70% (3/81) do que em ratos 2,69% (8/269), embora sem significância (p = 1,0000: 0,1250 a 32,00 CI). Ratos e camundongos parecem mostrar os reservatórios mais adequados hospedando H. diminuta um helmintos zoonótico. A presença desses roedores em todos os habitats possíveis pode atuar como um canal principal de transferência de parasitas através de vários habitats e pode representar um perigo para os humanos na área.

Occurrence of Hymenolepis diminuta: a potential helminth of zoonotic importance in murid rodents / Ocorrência de Hymenolepis diminuta: um helminto potencial de importância zoonótica em roedores murídeos

The study reveals the prevalence of a potential rodent-borne zoonotic helminth species, Hymenolepis diminuta in commensal rodents caught from irrigated and rain-fed areas of Swat, Pakistan. Three hundred and fifty rodents (269 rats and 81 mice) trapped during vegetative, flowering/fruiting and mature/harvesting stages of crops were studied from 2011-2013. Hymenolepisdiminuta eggs were identified on the basis of their shape, size, colour and markings on the surface of the egg shell and three pairs of embryonic hook-lets. Overall prevalence of H. diminuta was 3.14% (n=11/350). The highest prevalence 3.49% (n=5/143) of H. diminuta was noted at harvesting stages of the crops whereas the lowest 2.59% (n=2/77) during vegetative stage. Infection was higher in males 3.25% (n=7/215) than females 2.96% (n=4/135). Adult rodents were highly infected while no sub-adult was found infected. Infection was higher in mice 3.70% (3/81) than rats 2.69% (8/269) while no significance (p=1.0000:0.1250 to 32.00 CI). Rats and mice appears to show the most suitable reservoirs by hosting H. diminuta a zoonotic helminth. The presence of these rodents in all possible habitats can act as a main channel of transferring parasites through various habitats and can pose a hazard to humans in the area.

O estudo revela a prevalência de uma espécie potencial de helmintos zoonóticos transmitidos por roedores, Hymenolepis diminuta, em roedores comensais capturados em áreas irrigadas e alimentadas pela chuva de Swat, Paquistão. Trezentos e cinquenta roedores (269 ratos e 81 camundongos) presos durante os estágios vegetativo, floração/frutificação e maturidade/colheita das safras foram estudados de 2011-2013. Ovos de Hymenolepis diminuta foram identificados com base em sua forma, tamanho, cor e marcações na superfície da casca do ovo e três pares de anzóis embrionários. A prevalência geral de H. diminuta foi de 3,14% (n = 11/350). A maior prevalência 3,49% (n = 5/143) de H. diminuta foi observada na fase de colheita das lavouras, enquanto a menor 2,59% (n = 2/77) durante a fase vegetativa. A infecção foi maior nos homens 3,25% (n = 7/215) do que nas mulheres 2,96% (n = 4/135). Roedores adultos foram altamente infectados, enquanto nenhum subadulto foi encontrado infectado. A infecção foi maior em camundongos 3,70% (3/81) do que em ratos 2,69% (8/269), embora sem significância (p = 1,0000: 0,1250 a 32,00 CI). Ratos e camundongos parecem mostrar os reservatórios mais adequados hospedando H. diminuta um helmintos zoonótico. A presença desses roedores em todos os habitats possíveis pode atuar como um canal principal de transferência de parasitas através de vários habitats e pode representar um perigo para os humanos na área.

Prevalence of Hymenolepis nana and H. diminuta from Brown Rats (Rattus norvegicus) in Heilongjiang Province, China

Hymenolepis nana and Hymenolepis diminuta are globally widespread zoonotic cestodes. Rodents are the main reservoir host of these cestodes. Brown rats (Rattus norvegicus) are the best known and most common rats, and usually live wherever humans live, especially in less than desirable hygiene conditions. Due to the little information of the 2 hymenolepidid species in brown rats in China, the aim of this study was to understand the prevalence and genetic characterization of H. nana and H. diminuta in brown rats in Heilongjiang Province, China. Total 114 fecal samples were collected from brown rats in Heilongjiang Province. All the samples were subjected to morphological examinations by microscopy and genetic analysis by PCR amplification of the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene and the internal transcribed spacer 2 (ITS2) region of the nuclear ribosomal RNA gene. In total, 6.1% (7/114) and 14.9% (17/114) of samples were positive for H. nana and H. diminuta, respectively. Among them, 7 and 3 H. nana isolates were successfully amplified and sequenced at the COX1 and ITS2 loci, respectively. No nucleotide variations were found among H. nana isolates at either of the 2 loci. Seventeen H. diminuta isolates produced 2 different COX1 sequences while 7 ITS2 sequences obtained were identical to each other. The present results of H. nana and H. diminuta infections in brown rats implied the risk of zoonotic transmission of hymenolepiasis in China. These molecular data will be helpful to deeply study intra-specific variations within Hymenolepis cestodes in the future.

Infección por Hymenolepis diminuta en infante del municipio Girardot, Maracay, estado Aragua, Venezuela / Infection by Hymenolepis diminuta in infant from the Girardot municipality, Maracay, Aragua State, Venezuela

Se presenta un caso inusual de infección por Hymenolepis diminuta en infante de un año de edad residente en Maracay, estado Aragua. El hallazgo se realizó de manera fortuita por el personal del Laboratorio de Parasitosis Intestinales y Serología de Esquistosomiasis de la Dirección General de Salud Ambiental del Ministerio del Poder Popular para la Salud, a donde fueron remitidos ejemplares adultos del parásito eliminado de forma espontánea por el paciente. Antes de la expulsión del parásito, el paciente presentó sintomatología digestiva, fiebre y manifestaciones alérgicas. La representante del infante refirió la presencia de ratas y ratones en el jardín de la vivienda. Este caso se constituye en el primer informe de infección por H. diminuta en el estado Aragua. Se sugiere realizar investigación epidemiológica más rigurosa para determinar la prevalencia de himenolepiosis.

Presentation of an unusual case of Hymenolepis diminuta infection in a one-year old infant residing at Maracay, Aragua State. The finding occurred fortuitously by the staff of the Intestinal Parasites and Schistosomiasis Serology Laboratory of the General Direction of Environmental Health of the Ministerio del Poder Popular para La Salud, who received two adult forms of the parasite eliminated spontaneously by the patient. Before the expulsion of the parasite, the patient had digestive symptoms, fever and allergic reactions. The infant’s guardian referred the presence of rats and mice in the garden of the house. This case is the first report of this type of infection by H. diminuta in Aragua State. A more rigorous epidemiological investigation is suggested to determine the prevalence of himenolepiosis.

A Human Case of Hymenolepis diminuta in a Child from Eastern Sicily

We report a case of Hymenolepis diminuta infection in a 2-year-old child living in a suburban area of Catania, Italy. This case was initially referred to us as Dipylidium caninum infection, which was not cured after being treated twice with mebendazole. However, by analyzing the clinical presentation and stool samples we arrived to the diagnosis of H. diminuta infection. The case presented with atypical allergic manifestations which had never been reported as clinical features of symptomatic H. diminuta infection; remittent fever with abdominal pain, diffuse cutaneous itching, transient thoracic rash, and arthromyalgias. The patient was treated with a 7-day cycle of oral niclosamide, which proved to be safe and effective. This case report emphasizes that a correct parasitological diagnosis requires adequate district laboratories and trained personnel. In addition, we recommend the importance of reporting all H. diminuta infection cases, in order to improve knowledge on epidemiology, clinical presentation, and treatment protocols.

Infección por Hymenolepis diminuta en un niño del municipio Maracaibo, Estado Zulia, Venezuela / Infection by Hymenolepis diminuta in a child from the Maracaibo Municipality, Zulia State, Venezuela

Se presenta el primer caso descrito en el estado Zulia de un individuo infectado por Hymenolepis diminuta. El hallazgo fue fortuito, al realizar exámenes coproparasitológicos a un grupo de niños que viven en una comunidad de bajos recursos. Sus familiares refieren que, en vista de la frecuencia de síntomas digestivos del niño de 6 años (dolor abdominal y diarrea), recibía regularmente medicamentos antiparasitarios como piperazina, por parte del personal médico del programa Barrio Adentro. Al examen microscópico se observaron huevos de H. diminuta, Blastocystis hominis y quistes de Endolimax nana. Las condiciones higiénico-sanitarias de la vivienda, así como la referencia de presencia de ratas en el sector, confirman la posibilidad de la infección; a pesar de ello, ningún otro miembro del grupo familiar presentó huevos de esta especie en sus heces. Luego de recibir tratamiento específico con albendazol, no se detectaron huevos de H. diminuta en las heces.

The first case of an individual infected by Hymenolepis diminuta in Zulia State is presented. The finding was fortuitous, when doing coproparasitological examinations in a group of children living in a low income community. His family members refer that due to the frequency of digestive symptoms of the 6 year-old child (abdominal pain and diarrhea) he had been regularly prescribed anti-parasite drugs such as piperazine by the Barrio Adentro program medical staff. In the microscopic examination he showed H. diminuta and Blastocytis hominis eggs, and Endolimax nana cysts. The sanitary-hygienic conditions of the household, as well as the reference of rats in the area, confirming the possibility of this infection; in spite of that, no other member of the family group showed eggs from this species in their feces. After receiving specific treatment with albendazol, no H. diminuta were found in his feces.

Síndrome diarreico crónico debido a infección por hymenolepis diminuta: Reporte de un caso

La infección parasitaria del intestino delgado del hombre producida por cestodos conocidos como Hymenolepis diminuta o "tenia del ratón", es excepcional. Varios artrópodos coprozoicos sirven como huéspedes intermediarios. La ingestión de los hospederos intermediarios parasitados produce la infección en el hospedero definitivo y, accidentalmente, en el hombre, donde la infección es bien aceptada, sin un cuadro clínico específico, presentándose como diarrea, dolor abdominal difuso y otras manifestaciones inespecíficas. A nuestro centro fue llevado paciente masculino de 50 años de edad con Retardo mental, quien presentaba evacuaciones diarreicas múltiples con moco y sin sangre, anorexia, pérdida de peso y fiebre de un mes de evolución, por lo cual se ingresa. Durante su hospitalización, se realiza Videocolonoscopia evidenciándose abundantes helmintos en todo su trayecto. Se toman muestras para Biopsia, en las cuales se observan formas maduras e inmaduras de Hymenolepis diminuta. Posterior a tratamiento con Praziquantel, el paciente es dado de alta, por evolución satisfactoria.

The parasitic infection of the small bowel produced by cestodos acquaintances like diminuta Hymenolepis or "tape-worm of the mouse" is exceptional. Several coprozoic arthropods serve as intermediary guests. The ingestion of the intermediary parasitized inn-keepers produces the infection in the definitive inn-keeper and, accidental, in the man, where the infection is accepted well, without a clinical specific picture, appearing as diarrhea, abdominal diffuse pain and other unspecific manifestations. A 50-year-old masculine patient with mental delay was taken to our center, who presented multiple diarrheic evacuations with snot and without blood, anorexia, loss of weight and fever of a month of evolution, by which it is deposited. During his hospitalization, videocolonoscopy is realized progressing up to blind person, being found abundant helmintos in all its distance. Samples are taken for Biopsy, which demonstrate mature and immature forms of Hymenolepis Diminuta. Later to treatment with Praziquatel, the patient is discharged, for satisfactory evolution.