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.

Infections of Intestinal Helminth at Two Species of Field Mice, Apodemus agrarius and A. Peninsulae, in Gangwondo and Chungcheongnam-do, Korea

Rodents are important reservoirs of diseases affecting people and livestock, and are major sources of parasite contamination of agricultural products. We surveyed the infection status of intestinal helminths in 2 species of field mice, Apodemus agrarius and A. peninsulae, captured in the agricultural fields of Gangwon-do and Chungcheongnam-do, Korea. Total 83 mice (57 A. agrarius and 26 A. peninsulae) were collected in 2 surveyed areas, and the intestines of each mouse were opened with scissors, and then intestinal contents were examined with microscope. Total 6 species of intestinal helminth were detected in 61 (73.5%) out of 83 mice examined. Four species of nematode, i.e., Nippostrongylus brasiliensis, Aspiculuris tetraptera, Heterakis spp. and ascarid, were found in 40 (48.2%), 14 (16.9%), 11 (13.3%) and 13 (15.7%) mice respectively. One species of cestode, Hymenolepis diminuta and 1 unidentified egg were also detected in the intestines of 14 (16.9%) and 1 (1.2%) mice, respectively. Conclusively, this study identified 5 helminth species in the gastrointestinal tracts of wild rodents captured in some areas in central and northern Korea, and N. brasiliensis was the most prevalent (dominant) species rather than zoonotic ones.

Endoparasites of Small Mammals in Edo State, Nigeria: Public Health Implications

Some small mammals occur as household pests and harbour a number of parasites that could be of public health importance. This study profiled the helminth and protozoan parasites in trapped small mammals within and around human dwelling places (houses) located across 4 major towns (Auchi, Benin, Ekpoma, and Uromi) and environs in Edo state, Nigeria. Six genera (Apodemus sp., Crocidura sp., Mastomys natalensis, Mus musculus, Rattus sp., and Sorex sp.) were identified from 502 trapped small mammals. Overall, M. musculus (71.9%) and Rattus rattus (20.1%) were the most frequently trapped. In total, on examination of blood, gastrointestinal contents, and brain tissues, 12 helminth taxa (Angiostrongylus sp., Aspicularis sp., Capillaria sp., Gongylonema sp., Heterakis spumosa, Hymenolepis diminuta, Hymenolepis nana, Mastophorus muris, Moniliformis moniliformis, Nippostrongylus brasiliensis, Strongyloides sp., Trichosomoides sp., and Trichuris sp.), and 6 protozoan parasites (Babesia sp., Trypanosoma lewisi, Plasmodium sp., Eimeria sp., Isospora sp., and Toxoplasma gondii) were isolated. Most prevalent helminths with relatively heavy mean intensity were Strongyloides sp. and Heterakis spumosa, while Plasmodium, Eimeria, and Isospora were the most prevalent protozoan parasites. Generally, intrinsic factors like sex and age had marginal influence on the rate and burden of infection in M. musculus and R. rattus. Although the infection rate and prevalence of zoonotic parasites were low, they were largely recovered in rodents from Ekpoma. This study elucidates the public health implication of the presence of zoonotic parasites in these small mammals.

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.

Evaluación experimental de Ulomoides dermestoides (Tenebrionidae) como hospedero intermediario de Hymenolepis diminuta / Experimental evaluation of Ulomoides dermestoides (Tenebrionidae) as an intermediate host of Hymenolepis diminuta

El objetivo del estudio fue determinar si Ulomoides dermestoides se comporta como hospedero intermediario de Hymenolepis diminuta, por lo que cien de ellos se infectaron experimentalmente con huevos del cestodo. Como resultado se obtuvo que en el 92% de los insectos se formaron cisticercoides que, inoculados en ratas de laboratorio, desarrollaron el estadio adulto con cuyos huevos se repitieron nuevas infecciones obteniendo los mismos resultados, por lo que se puede señalar que U. dermestoides experimentalmente se comporta como hospedero intermediario...

The aim of the study was to determine if Ulomoides dermestoides behaves as an intermediate host of Hymenolepis diminuta, therefore one hundred of them were experimentally infected with tapeworm eggs. As a result, it was found that in 92% of the insects formed cysticercoids which, inoculated in laboratory rats, developed the adult stage. These adults produced eggs with which the infection process was repeated, obtaining the same results. Therefore it can be said that U. dermestoides experimentally acts as an intermediate host...

Endoparasites of rodents and their zoonotic importance in Germi, Dashte-Mogan, Ardabil province, Iran

In order to verify the infectivity of rodents with endoparasites in Germi [Dashte-Mogan, Ardabil Province] the current study was undertaken. Using live traps, 177 rodents were trapped during 2005-2007. in field laboratory, all rodents were bled prior to autopsy, frozen at -20[degree sign] C, and shipped to the School of public Health, Tehran University of Medical Sciences, Iran. In parasitological laboratory, every rodent was dissected and its different organs were examined for the presence of any parasite. Blood thick and thin smears as well as impression smears of liver and spleen were stained with Geimsa and examined microscopically. Two species of rodents were trapped; Meriones persicus [90.4%] and Microtus socialis [9.6%]. The species of parasites found in M. persicus and their prevalences were as follows: Hymenolepis diminuta [38.8%], Hymenolepis nana [2.5%], Trichuris sp. [40.6], Mesocestoides larva [=tetraptrathyridium] [3.1%], Capillaria hepatica [6.9%], Moniliformis moniliformis [11.3%], Syphacia obvelata [2.5%], Taenia endothoracicus larva [0.6%], Physaloptera sp. [0.6%], Dentostomella translucida [0.6%, Heligmosomum mixtum [0.6%], Strobilocercus fasciolaris [0.6%], and Aspiculuris tetraptera [11.8%]. There were no statistical differences between male and female for infectivity with parasites in either M. persicus or M. socialis. No blood or tissue protozoan parasite was found in any of the rodents examined. Among different species identified, some had zoonotic importance. Therefore, the potential health hazard of these species needs to be considered to prevent infectivity of humans

Rodents as reservoir host of intestinal helminthes in different Egyptian agroecosystems

Hymenolepis diminuta were detected in rodents in all zones surveyed Governorates under studied [Suez, Menoufia, Giza, Damietta and Beni-Sewaf]. The highest infestation recorded at Suez and Demiatta Governorates. On the other hand, rodents at Menoufia and Beni-Sewaf showed there is no convincing evidence that they infested with H. diminuta. The existence of one species of nematode namely, Streptopharagus kuntzi were recorded at Suez, Giza and Demiatta Governorates only. While Menoufia and Beni-Sewaf Governorates showed no convincing evidence that, they infested with nematode. Worms were recovered from Norway rats. Data indicated that Rattus norvegicus were the most vulnerable species at infection with H. diminuta and Streptopharagus kuntzi. Summer is highly infested with nematode in comparison with other seasonal study

Hymenolepis diminuta in a child from rural area.

We report a rare case of Hymenolepis diminuta infection in a 12-year-old girl from a rural area of Devghar.

Lead concentrations in some organs of the rat meriones libycus and its parasite Hymenolepis diminuta from Riyadh city, KSA

In the present study, the tape worm Hymenolepis diminuta was chosen to estimate lead bioaccumulation in an urban area highly polluted with lead [the industrial area] and another less polluted one [Al-Karj road] at Riyadh City, K.S.A. Lead concentrations were found 38 to be 32 and 15 times in the parasite [H. diminuta] than in the intestine, liver and kidney of the host [Meriones libycus]. Thus, the proposed model of cestode parasite-rat as bio-indicator of lead pollution seems to be promising in the terrestrial habitat

A survey on intestinal parasites of soldiers in Korea

Total of 2,643 Korean soldiers were examined of their stool for parasitic infections by both cellophane thick smear and formalin-ether concentration techniques from August 1983 to December 1985. Out of them, 73.6% were free from any parasite, 22.6% were ova positive and 4.0% cyst positive. The ova positive rates by species were Ascaris lumbricoides 2.0%, Trichuris trichiura 13.0%, hookworm and Trichostrongylus orientalis 0.08% respectively, Clonorchis sinensis 7.6%, Metagonimus yokogawai 1.1%, Paragonimus westermani 0.08%, Echinostoma hortense 0.04%, Fibricola seoulensis 0.9%, Taenia sp. 0.3%, Hymenolepis nana 0.2% and H. diminuta 0.04%. Most of them (87.3%) were positive by a species, 11.9% by two and 0.8% by 3 species. The cyst positive rates were Entamoeba histolytica 0.6%, E. coli 1.4%, Endolimax nana 1.7%, Iodoameba butschlii 0.04% and Giardia lambla 0.9%. Among the cyst positives, 89.5% were positive by a species, 7.6% by two and 0.5% by 3 species. The intestinal parasite infections among the Korean soldiers decreased distinctly compared with previous data.

Case report on human infection of Hymenolepis diminuta

There has been no report on human infection of Hymenolepis diminuta in Korea until the first 3 cases were reported by our members after the identification of those eggs in stool in 1964. However, the distinct differentiation between H. diminuta and H. nana would often be difficult by the shape of eggs without adult worm. In 1965, authors found the additional case revealed the eggs in stool and succeeded to obtain three adult worms of H. diminuta from 10 years old boy in Pusan. The characteristic morphology of egg and adult worm were discussed to compare to those of H. nana. Conclusively, the first human infection of H. diminuta in Korea was reported after the identification both the eggs and adults worms

Studies on the parasitic helminths of Korea II. Parasites of the rat, Rattus norvegicus Erxl. in Seoul, with the description of Capillaria hepatica(Bancroft, 1893) Travassos, (1915)

An investigation of the helminth parasites of house rat R. norvegicus Erxl. in Seoul has been carried on four years. A total of 325 rat was examined. Ten species of helminths were considered, of which 4 species were recored for the first time from Korea. The adult worm of Capillaria hepatica, the most common parasite of house rats in Seoul, was observed experimentally, and provided a more complete description of this worm.

Studies on the metabolism of C(14)-proline in some parasitic helminths

A comparison of the absorption and incorporation of C(14)-proline into protein by the 7 kinds of helminth parasites is presented. The radioactivity of free amino acid fraction is greater than that of protein fraction in all the worms, and only a small amount of exogenous labeled proline is incorporated into tissue protein. In general, the pattern of C(14)-proline uptake and its incorporation into protein shows rapid linear increase during the period of 15 to 30 min and reaches the maximum at 60 min after incubation, and then the equilibrium state was maintained throughout further incubation.

Autoradiographic studies on some parasitic helminth

Direct contact method of autoradiography was utilized in studying the distribution of exogenous C(14)-proline in Clonorchis sinensis, Eurytrema pancreaticum, Hymenolepis diminuta and Dipylidium caninum. The most distinct autoradiogram were obtained after 60 min of incubation, corresponding to the maximal absorption of C(14)-proline in these parasite. The radioactivitity of this labeled amino acid was chiefly concentrated in reproductive organs, especially egg-containing uterine tubules.