First survey on zoonotic helminthosis in urban brown rats (Rattus norvegicus) in Spain and associated public health considerations.

The brown rat, Rattus norvegicus, with a worldwide distribution, is the most commensal species among synanthropic rodents, since its main habitat, in urban as well as in rural areas, is always linked to humans. Therefore, people living in close proximity to rodent populations can be exposed to infection. Whereas bacteria and viruses are the best known rat-associated zoonoses in urban environments, the role of brown rats as reservoirs for helminth parasites and the associated risk for humans are less well known. Specifically, this role has not been analyzed in Spain to date. A total of 100 R. norvegicus trapped in the sewage system (n = 85), and parks (n = 15) of Barcelona was examined. The overall prevalence of helminth infection was 85%. The helminths found were Hymenolepis nana (17%), H. diminuta (33%) (Cestoda), Calodium hepaticum (17%), Eucoleus gastricus (28%), Aonchotheca annulosa (12%), Trichosomoides crassicauda (7%), Nippostrongylus brasiliensis (46%), Heterakis spumosa (62%), Gongylonema neoplasticum (20%) (Nematoda) and Moniliformis moniliformis (6%) (Acanthocephala). Five of the ten helminth species are considered zoonotic parasites, with rats acting as reservoirs for human infection, i.e. H. nana, H. diminuta, C. hepaticum, G. neoplasticum and M. moniliformis. G. neoplasticum and M. moniliformis are reported for the first time in urban rats in Europe. H. nana, H. diminuta and C. hepaticum are the most widespread species in European cities. For H. nana and C. hepaticum, rats act as effective spreaders of the human infective stage (eggs). For H. diminuta, G. neoplasticum and M. moniliformis, rats act as indirect reservoirs of the zoonoses since the eggs shed by the rats are infective for their insect intermediate hosts only. Medical practitioners need to be made aware of the range of parasites carried by rats, as there is a realistic likelihood that ill health currently caused by rat infestations may be misdiagnosed.

Effect of Mass Stool Examination and Mass Treatment For Decreasing Intestinal Helminth and Protozoan Infection Rates in Bolivian Children: A Cross-Sectional Study.

Bolivia is one of the countries with a high intestinal helminth and protozoan infection rate. Despite the high prevalence of the parasitic infection, nationwide preventive measures for Bolivian children have not yet been implemented. We evaluated the effect of mass stool examination and treatment as a strategy for decreasing the infection rate. This study was conducted between 2013 and 2015 in children aged 2-18 years. A total of 2,033 stool samples (575 in 2013, 815 in 2014 and 642 in 2015) were collected and examined using the formalin-ether medical sedimentation method. As an anthelminthic medicine, nitazoxanide was given to all infected children within 2 months post-examination, each year. The effect of mass stool examination and treatment was evaluated based on the changes in the overall or individual parasitic infection rates during the study period. The overall parasitic infection rate decreased significantly from 65.2% in 2013 to 43.0% in 2015; a 22.2 percentage point decrease (P<0.001). Protozoan infection accounted for a large portion of the parasitic infections, in the following rates: 62.4% in 2013, 49.3% in 2014, and 41.0% in 2015. The rate of the most common helminth infection, Hymenolepis nana, decreased significantly from 9.0% in 2013 to 6.4% in 2014 to 3.4% in 2015 (P<0.001). Prevalence of the most common pathogenic protozoan infection, Entamoeba histolytica, decreased significantly from 19.0% in 2013 to 3.0% in 2015 (P<0.001). Conversely, the rate of Giardia intestinalis increased significantly from 16.5% in 2013 to 21.2% in 2015 (P<0.01). Mass stool examination and treatment for intestinal helminth and protozoan infections was effective for decreasing the overall parasitic infection rate in the study population, excluding Giardia intestinalis. Further studies on the long-term effect of mass stool examination and treatment for decreasing all intestinal parasitic infection rates in Bolivian children are needed.

Cryptic diversity in hymenolepidid tapeworms infecting humans.

An adult hymenolepidid tapeworm was recovered from a 52-year-old Tibetan woman during a routine epidemiological survey for human taeniasis/cysticercosis in Sichuan, China. Phylogenetic analyses based on sequences of nuclear 28S ribosomal DNA and mitochondrial cytochrome c oxidase subunit 1 showed that the human isolate is distinct from Hymenolepis diminuta and Hymenolepis nana, the common parasites causing human hymenolepiasis. Proglottids of the human isolate were unfortunately unsuitable for morphological identification. However, the resultant phylogeny demonstrated the human isolate to be a sister species to Hymenolepis hibernia from Apodemus mice in Eurasia. The present data clearly indicate that hymenolepidid tapeworms causing human infections are not restricted to only H. diminuta and H. nana.

A new modified technique for concentrating intestinal parasites.

The present study evaluated the diagnostic performance of a modification of the formol ethyl acetate concentration technique, with the addition of 25% acetic acid as compared with formol ethyl acetate concentration technique (FEA) and fecal parasite concentrator kit Fresh fecal material, free of ova and parasites, was pooled in a ratio of 1:4 with 10% buffered formalin to prepare a standardized specimen. Sufficient volumes of formalin-fixed suspension of Giardia lamblia cysts, Entamoeba histolytica cysts, Cryptosporidium oocysts; Ascaris lumbricoides ova, Necator americanus, Taenia spp. and Hymenolepis nana were used to seed individually 3-ml portions of the fecal specimen. The 3-ml samples were split in three parts, one processed by FEA, a second part with FPC and the third part by the modified FAEA; six smears from each sediment were examined by light microscopy. FAEA technique gave the clearest sediments and the highest numbers in most of the parasites. FAEA resulted in a higher percenttage of H. nana, Taenia spp., N. americanus, and G. lamblia per one ml of stool compared with FEA method. When compared with FPC, the same results were achieved in addition to E. histolytica.

A behavioral study of the beetle Tenebrio molitor infected with cysticercoids of the rat tapeworm Hymenolepis diminuta.

The host-parasite relationship, Tenebrio molitor-Hymenolepis diminuta, was analyzed. The learning behavior of infected and uninfected (control) beetles in a T-maze was compared. The infected beetles moved much slower in the T-maze than the controls. The infected beetles reached the same level of learning as the controls. However, they needed more trials than the controls. The effect of the infection was already distinct after the first week and even higher after the second week. This indicates that the initial phase of infection caused stress in the beetles. Longer infection did not worsen their ability to learn. Thus, the parasites clearly changed the behavior of their intermediate host and probably made them more susceptible to their final host, the rat.

[Cestode infections in Poland in 2003]. / Tasiemczyce w 2003 roku.

In 2003, 218 intestinal cestode infections were registered in Poland. Among them 157 were caused by Taenia saginata, 4 by T. solium, 32 by Taenia sp., 1 by Diphyllobothrium latum,. Moreover, 34 cases of cystic echinococcosis were also registered. The obtained results confirmed decreasing frequency of intestinal cestodes in Poland.

The Hymenolepis diminuta-golden hamster (Mesocricetus auratus) model for the evaluation of gastrointestinal anticestode activity.

A novel laboratory anticestode assay was developed using Hymenolepis diminuta in the hamster. The commercial anticestode compounds, praziquantel, bunamidine, and niclosamide were active against patent infections of Hymenolepis diminuta in golden hamsters (Mesocricetus auratus) when given orally at 3.125, 100, and 200 mg/kg, respectively. The gastrointestinal nematode anthelmintics, cambendazole and mebendazole, were active at 50 mg/kg. Rafoxanide (fasciolicide) was active at 25 mg/kg, the lowest level tested. The coccidiostat, nicarbazin, was active at experimental levels (800 mg/kg and up). The anthelmintic-ectoparasiticide (endectocide), ivermectin, was inactive against the tapeworm at 0.5 mg/kg, as expected.

[Cestode infections in Poland in 2002]. / Tasiemczyce w 2002 roku.

In 2002, 264 intestinal cestode infections were registered in Poland. Among them 193 were caused by Taenia saginata, 3 by T. solium, 53 by Taenia sp., 1 by Hymenolepis nana, 1 by Diphyllobothrium latum, 1 by Hymenolepis diminuta. Moreover, 40 cases of cystic echinococcosis were also registered. The obtained results confirmed decreasing frequency of intestinal cestodoses in Poland.

Seroprevalence of anti-cysticercus antibodies among the children living in the urban environs of Maputo, Mozambique.

Blood and faecal samples were collected from 269 children (aged 0-15 years) who lived in the urban environs of Maputo, the capital city of Mozambique. Antibodies against Cysticercus cellulosae were detected, at a titre of at least 1:100, in 56 (20.8%) of the blood samples. When the stool samples were checked for Taenia solium and other helminths, both as direct smears and after formalin-ether concentration, 180 (67.0%) were found to contain at least one helminth species. The parasites most commonly detected in the faecal samples were Trichurus trichiura (36.0%) and Ascaris lumbricoides (35.7%). Only in one sample (0.4%) were gravid proglottids of Ta. solium detected, but Hymenolepis nana (1.1%) and H. diminuta (0.4%) were also found. A positive correlation between seropositivity for anti-cysticercus antibodies and subject age, and positive associations between such seropositivity and infection with A. lumbricoides and infection with Tr. trichiura were observed. None of the other demographic and environmental factors investigated--the child's sex, religion and access to toilets and/or piped water, the type of house in which he or she lived, the number of individuals in the household to which he or she belonged, and whether that household had pets or raised livestock--showed any apparent association with either the seroprevalence of anti-cysticercus antibodies or infection with any intestinal helminth. The use of water from the common sewage-drainage system for agricultural irrigation in the study area probably causes most of the contamination with intestinal parasites.

Comparative clinical studies of nitazoxanide, albendazole and praziquantel in the treatment of ascariasis, trichuriasis and hymenolepiasis in children from Peru.

Three randomized clinical studies were conducted in 2000 to evaluate the efficacy of nitazoxanide paediatric suspension compared to albendazole in the treatment of ascariasis and trichuriasis and praziquantel in the treatment of hymenolepiasis in children from Cajamarca, Peru. Nitazoxanide was administered at a dose of 100 mg (age 1-3 years) or 200 mg (age 4-11 years) twice daily for 3 days, albendazole as a 400-mg single dose and praziquantel as a 25-mg/kg single dose. Post-treatment parasitological examinations were carried out on 3 faecal samples, each collected on a different day between 21 and 30 days following initiation of treatment. Nitazoxanide cured 89% (25/28), 89% (16/18) and 82% (32/39) of the cases of ascariasis, trichuriasis and hymenolepiasis respectively compared with 91% (32/35), 58% (11/19) and 96% (47/49) for the comparator drugs. Each of the drugs produced egg reduction rates in excess of 98%. There were no significant adverse events or abnormalities in haematology or clinical chemistry values or urinalysis.

Correlaçäo entre condiçöes de saneamento básico e parasitoses intestinais na populaçäo de Assis, Estado de Säo Paulo / Correlation between sanitation conditions and enteroparasitoses in the population of Assis, Säo Paulo State, Brazil

Foi estudada a distribuiçäo dos enteroparasitos mais freqüentes na populaçäo de Assis, Säo Paulo, de 1990 a 1992. Foram analisados 18.366 exames oriundos de seis postos de atendimento sanitário (PAS): Vila Marialves, Vila Progresso, Centro, Vila Xavier, Vila Fiúza e Vila Bonfim. A prevalência de enteroparasitoses geral foi 23,3 por cento. Os enteroparasitos mais encontrados foram: Giardia intestinalis (8,7 por cento), Ascaris lumbricoides (5,5 por cento), Trichuris trichiura (2,4 por cento) e Hymenolepis nana (1,9 por cento). Na Vila Marialves, regiäo de baixo nível sócio-econômico essas freqüências foram, respectivamente: 17 por cento; 13,1 por cento; 5,9 por cento e 4,2 por cento. A faixa etária 3 a 12 anos apresentou maior número de indivíduos parasitados. Estabeleceu-se uma correlaçäo entre as condiçöes de saneamento básico, expressos pelo número de ligaçöes de água e esgoto, e a freqüência de parasitoses. Houve queda na freqüência de parasitoses nos PAS entre 1990 e 1992, coincidindo com o aumento do número de ligaçöes de água e esgoto nestas regiöes

Enteroparasitos en niños residentes en zona rural del Partido del Carmen de Patagones: Provincia de Buenos Aires, Argentina / Enteroparasites in children living in rural areas at the Partido de Carmen de Patagones: province of Buenos Aires, Argentina

Como parte del programa de atención primaria de la salud (APS) del año 1996, y en virtud que no existían datos epidemiológicos referidos a enteroparásitos hallados en niños de 0 a 14 años, residentes en una zona rural del Partido de Carmen de Patagones, Provincia de Buenos Aires, es que se realizó el presente estudio epidemiológico descriptivo. Se estudiaron 210 niños a los que se les efectúo un estudio parasitoscópico seriado de materia fecal y mucus anal. Los resultados mostraron que el 60,5 por ciento de la población estudiada era portadora de algún parásito intestinal. El monoparasitismo hallado fue de 67 por ciento, mientras que 33 por ciento restante presentó entre 2 y 5 formas parasitarias. El espectro parasitario fue el siguiente: entamoeba coli 31,5 por ciento, giardia lamblia 24,7 por ciento; enterobius vermicularis 18 por ciento; hymenolepis nana 10,4 por ciento; blastocystis hominis 10,4 por ciento; 10,3 por ciento; chilomastix mesnili 2,5 por ciento; entamoeba hystolytica 0,9 por ciento y trichuris 0,5 por ciento. La distribución parasitaria en los distintos sectores estudiados fue en general homogénea excepto para H. nana la cual presentó una prevalencia más altas en zonas de riesgos con relación a la zona seca. Los resultados obtenidos fueron comunicados a las autoridades sanitarias correspondientes

Human infection with Hymenolepis diminuta: case report from Spain.

We report a case of Hymenolepis diminuta infection in a human. The patient was a 5-year-old girl referred to us through the onset of a cyanotic attack. Treatment with a single dose (10 mg/kg of body weight) of praziquantel was ineffective, but the parasite was eradicated after three treatment cycles with the same drug at dosages of 25 mg/kg/day for 5 days.

Application of lactophenol cotton blue for identification and preservation of intestinal parasites in faecal wet mounts.

Wet mounting is the simplest and easiest technique for the examination of faeces. Routinely employed wet mounts in most of the laboratories include saline, iodine and buffered methylene blue. Lactophenol cotton blue [LCB] staining--mounting medium is commonly used for microscopic identification of fungi. LCB and its modifications were tested as staining mounting medium on parasite positive faecal samples [both fresh as well as formalin fixed] to stain and demonstrate morphology and to preserve parasitic elements [trophozoites, cysts, ova and larvae] in wet mounts. Protozoal cysts [Entamoeba histolytica and Giardia lamblia], helminthic OVA [Ancylostoma duodenale, Ascaris lumbricoides, Enterobius vermicularis, Taenia solium and Hymenolepis nana] and larvae [Strongyloides stercoralis] were well-stained and preserved their morphology in nailpolish enamel sealed LCB-faecal mounts. Morphology was better appreciated in LCB-formalin fixed faecal mounts as compared to LCB fresh faecal mounts and was well preserved by the end of twelve weeks.

Estudio epidemiológico de la infección por hymenolepis nana en la provincia de Ciego de Avila, Cuba / Epidemiological study on hymenolepis nana infection in Ciego de Avila Province, Cuba

An epidemiological study on H. nana infection was carried out in Ciego de Avila province, Cuba, fron 1981 to 1995. In this 15 years period 3,108,422 stool samples were examined for parasites, H. nana eggs were found in 250 (0,008 percent). Seasonal influence of this parasitism was not detected. There were more cases in children than in adults, with males prevaling over females. The more frequent symptoms and signs were abdominal pain, diarrhea and anorexia which relationships with food habits, dwelling characteristics, children day care center and school orchards are analyzed

Interactions between rat C-reactive protein and adult Hymenolepis diminuta.

Interactions between adult Hymenolepis diminuta and rat C-reactive protein (CRP) were investigated in vivo and in vitro. Using an ELISA technique, serum levels of CRP were monitored in rats infected with 100 cysticercoids. Although infection increased the level of this protein in the early stages of parasitization, the increase was not significant until 35 days post-infection (p.i.). Secondary infections did not enhance the response. When H. diminuta was cultured in the presence of CRP, reduced worm motility and opaque areas were observed and electron microscopical studies revealed shedding of microtriches and lysis of the tegument. Initially, damage was restricted to the strobila which correlated with the regional distribution of phosphorylcholine as visualized using immunofluorescence.

Infecciones por taenia sp y otros cestodos intestinales en pacientes de consultorios y hospitales públicos del sector norte de Santiago de Chile: 1985-1994 / Taenia sp and other intestinal cestode infections in individuals from public outpatient clinics and hospitals from the north sector of Santiago, Chile: 1985-1994

During 1985-1994 period, 70,642 parasitological stool examinations were perfomed. The exam was made to each patient which presenting gastrointestinal symptoms or nutritional problems, specially in children. 59,960 out of the 70,642 examinations corresponded to 1 month -15 years old chidren, 4,280 to 16-30 years old individuals and 6,402 to up to 30 years old adults. The infection rates (x 100,000) were: taenia sp, 86; hymenolepis nana, 1,165; diphyllobotrium sp, 4 and hymenolepis diminuta, 1. In this period, 11 cases of infection by taenia saginata were detected, and none taenia solium infection. Although infections rates by intestinal cestodes were higher in males than females, in the taenia sp. infection the difference was not statistical significative. Médico-veterinary control of animals slaughtered in abbatoirs and the improvement of sanitary conditions in the last two decades have contributed to the control of most of human intestinal cestodiases