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PubMed2005

Observations on helminth infections of free-living and captive rheas (Rhea americana) in Brazil.

The present work describes helminth infection of eight free-living and 12 captive rheas (Rhea americana) from, respectively, Pantanal of Mato Grosso do Sul State, and Jaboticabal, Sao Paulo State, Brazil. Captive birds were young and had a high mortality rate, while free-living birds were adult and apparently healthy. Infections were evaluated by post-mortem examination of internal organs and recovery of helminths using standard parasitological procedures. Seven species of nematodes (Sicarius uncinipenis, Torquatoides crotophaga, Deletrocephalus dimidiatus, D. cesarpintoi, Paradeletrocephalus minor, Capillaria venteli and Dicheilonema rheae) and two species of cestodes (Houttuynia struthionis and Chapmania tauricolis) were identified. P. minor, which inhabits the large intestine, was the most common helminth in free-living birds (63.9%). In captive rheas, a mean parasitic load of 173 helminths per host was found. The gizzard of these birds was the most parasitized organ and S. uncinipenis was most common (92.5%). Parasitism of free-living and captive birds and associated pathology are discussed.

Animals↗
PubMed2001

A study of risk factors for intestinal helminth infections using epidemiological and anthropological approaches.

This study. conducted in Kisumu District, Kenya, identified important risk factors for infection with intestinal helminths using traditional epidemiological methods. This was combined with a rapid assessment study using qualitative methods, which focused on sanitation practices and local illness perceptions. The multiple logistic regression analysis revealed that the absence of latrines was a significant predictor for hookworm infection with an odds ratio (OR) of 1.9. The analysis also revealed that households without soap had a 2.6 times higher risk of being infected with Ascaris lumbricoides compared with households where soap was available, and that the number of inhabitants living in a household was a significant predictor for infections with hookworms (OR=3.2). Furthermore, the presence of children of 5 years and under in the household was a predictor for infection with A. lumbricoides (OR=2.7), while the absence of this age group was a predictor for hookworm infection (OR=3.8). The qualitative part of the study revealed that people did not consider worms as a serious health threat, but as a nuisance. Among the population. latrines were seen as beneficial because they were believed to prevent disease, to provide privacy and to keep the environment free of faeces. Handwashing was done many times a day but usually not with soap, which was mainly used when bathing or washing the whole body. Many inhabitants in a household or the presence of children of 5 years and under were never mentioned as being a disadvantage, and these elements would therefore be difficult to include in a control strategy. Since the lack of latrines and of soap were identified as risk factors for infection, while latrines, soap and medicine were seen as assets by the population, it is suggested that helminth control interventions should be concentrated within these areas in this particular society.

Age Distribution↗
PubMed2004

Helminthic infections of the liver.

Human helminthic infestation is exceedingly common on a global scale, with as many as 1.5 to 2 billion people affected worldwide. Helminths (parasitic worms) that infect the liver and hepatobiliary system include nematodes (roundworms), cestodes (tapeworms), and trematodes (flatworms or flukes). The majority of morbidity and mortality from these infestations is caused by the host immune response to the larvae or adult worm. Helminthic disease manifestations vary from the extremes of asymptomatic carriage to cirrhosis and decompensated liver disease. Current basic science and clinical research focus on improvements in medical therapy, mass screening and chemoprophylaxis, and the development of preventative vaccine strategies.

Helminthiasis↗
PubMed2005

Helminthic Infections of the Liver.

Human helminthic infestation is exceedingly common on a global scale, with as many as 1.5 to 2 billion people affected worldwide. Helminths (parasitic worms) that infect the liver and hepatobiliary system include nematodes (roundworms), cestodes (tapeworms), and trematodes (flatworms or flukes). The majority of morbidity and mortality from these infestations is caused by the host immune response to the larvae or adult worm. Helminthic disease manifestations vary from the extremes of asymptomatic carriage to cirrhosis and decompensated liver disease. Current basic science and clinical research focus on improvements in medical therapy, mass screening and chemoprophylaxis, and the development of preventative vaccine strategies.

Journal Article↗
PubMed2000

Chronic immune activation associated with intestinal helminth infections results in impaired signal transduction and anergy.

Helminthic parasites cause widespread, persistent infections in humans. The immigration of Ethiopians to Israel (a group denoted here by "Eth."), many of them infested with helminths and in a chronic immune-activation state, enabled us to investigate the effects of such immune activation on immune responses. We studied the immune profile and immune functions of 190 Eth. and Israeli non-Eth. (Isr.) highly, partially, or non-immune-activated individuals. Immune cells from highly immune-activated individuals were defective in several signaling responses, all of which were restored gradually following anti-helminthic treatment. These cells showed poor transmembrane signaling, as seen by the phosphorylation of various tyrosine kinases and of the MAPK kinases, ERK1/2 and p38; deficient degradation of phosphorylated IkappaBalpha; increased expression of cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), which appears to block proliferative responses in these cells; decreased beta-chemokine secretion by CD8(+) cells after stimulation; and reduced proliferation to recall antigen stimulation. Highly immune-activated individuals also showed decreased delayed-type skin hypersensitivity responses to recall antigen before deworming. These findings support the notion that chronic helminthic infections cause persistent immune activation that results in hyporesponsiveness and anergy. Such impaired immune functions may diminish the capacity of these individuals to cope with infections and to generate cellular protective immunity after vaccination.

Abatacept↗
PubMed2003

Could control of soil-transmitted helminthic infection influence the HIV/AIDS pandemic.

In May 2001, the World Health Assembly (WHA) estimated that two billion people were infected by soil-transmitted helminths (S-THs) and schistosomiasis, worldwide. The WHA urged member states to recognise that there can be synergy between public health control programmes for S-THs, schistosomiasis and other diseases. This is particularly relevant to the new dimension created by the HIV/AIDS epidemics in the same impoverished communities and countries where helminthiasis is hyperendemic. Immunological adaptation between humans and parasitic helminths has developed during evolution. Review of 109 research papers, 76% (83/109) of which, were published between 1995 and February 2002, revealed increasing evidence that this relationship may have created an opportunity for more rapid infection by the human immunodeficiency virus (HIV), as well as quicker progression to AIDS. Moreover, the efficacy of some vaccines against HIV is likely to be impaired by chronic helminthiasis. For this, there is strong, indirect evidence. There is an urgent need for parasitologists, epidemiologists, immunologists and virologists to undertake comprehensive, transdisciplinary research. On the other hand, there is no current evidence that immunosuppression by HIV facilitates helminthic infection. The situation in regard to strongyloidiasis, however, is not yet clear.

Animals↗
PubMed2006

Targeting newly enrolled low-age school children for the control of the intestinal helminth infection in rural Nepal.

This study aims to identify an effective intervention group for the control of the intestinal helminth infection among school-age children in rural Nepal. We examined 1677 stool samples of school-age children from 25 schools and 1014 samples from 25 communities in rural Nepal. We used formalin-ether sedimentation technique for the microscopic examination of the stool samples and identified three major intestinal helminths: Ascariasis lumbricoides, hookworm and Trichuris trichiura. Our results revealed that the newly enrolled under-6-year-old children at the schools were more widely infected with at least one of the three major helminths than those in the communities (odds ratio [OR] 2.29). We detected a significant difference in the prevalence of A. lumbricoides (OR 1.70), hookworm (OR 2.57) and T.trichiura (OR 3.23) between under-6-year-old children at the schools and those at the communities. The study results suggest that an appropriate deworming programme is needed for the newly enrolled under-6-year-old children in the primary schools in Nepal.

Adolescent↗
PubMed1988

[The prophylactic effect of albendazole containing a pulse-release bolus on gastrointestinal helminth infection in calves].

The prophylactic effect of an albendazole containing 'pulse release' bolus on gastrointestinal helminth infection in calves during their first grazing season was tested on a farm in the Netherlands in 1986. Thirty calves were divided into two groups of young calves and two of old calves. On being turned out to grass, calves of one of these groups were given a bolus containing 3 x 2 grammes of albendazole, to be released after thirty-one, sixty-two and ninety-three days. The treated young calves showed a much lower egg-output, produced a lower infestation of herbage, displayed significantly lower pepsinogen levels and showed a significantly better gain in weight compared with the untreated young calves. Differences were not observed between the two groups of older calves, probably because of the fact that one of the treated calves had lost the bolus at an earlier stage.

Albendazole↗
PubMed1991

Production of IL-10 by CD4+ T lymphocytes correlates with down-regulation of Th1 cytokine synthesis in helminth infection.

After the onset of parasite egg deposition, mice infected with the helminth Schistosoma mansoni mount strong Th2 cytokine responses in the absence of significant Th1 cytokine synthesis. To examine the basis of this immunoregulatory state, spleen or lymph node cells from schistosome-infected mice were stimulated with parasite-specific Ag and the supernatants tested for their capacity to suppress IFN-gamma synthesis by a Th1 cell line. Strong inhibition was observed that was neutralized by a mAb against IL-10, a cytokine previously shown to down-regulate Th1 cytokine synthesis. By means of ELISA measurements the production of IL-10 in schistosome infection was confirmed and shown to depend on CD4+ T cells. IL-10 synthesis stimulated by either mitogen or Ag was observed only at those stages of infection when Th2 response induction and Th1 cytokine down-regulation also occurred and was not detected in mice vaccinated with attenuated parasites. Moreover, the addition of the neutralizing anti-IL-10 mAb to Ag-stimulated spleen cell cultures from infected mice caused a dramatic augmentation in IFN-gamma synthesis. These findings suggest that IL-10 is responsible for the down-regulation of Th1 responses observed in schistosome infections, a phenomenon that may enable the parasite to escape potentially harmful cell-mediated responses.

Animals↗
PubMed1976

Blowfly strike in the breech region of sheep in relation to helminth infection.

The incidence of breech strike in radically mulesed weaner sheep was reduced from about 50% to about 5% by suppression of helminth infection. Prediposition of sheep to flystrike appeared to result from the helminths causing diarrhoea and soiling of the wool in the breech region. Wethers were struck more frequently than ewes. The efficiency of control of breech strike in mulesed weaners is considered in relation to helminth control and crutching.

Animals↗
PubMed1999

Relationship between system of raising Egyptian buffaloes and the effect of climate conditions on the helminthic infection rate, middle Delta, Egypt.

No doubt climate conditions are of sound influence in both prevalence of helminthic infection and the physiology of the host. Fewer studies have been done on this relationship on farm animals. To complete the view, one thousand, two hundred and seventy eight buffaloes owned by farmers from 160 herds belong to 32 villages in the middle Delta of Egypt were randomly chosen to study factors which influence the infection with gastrointestinal parasites. Relationship between number of parasites, herd size, resources of water and season of the year were investigated. The main results showed that: (1) Fasciola gigantica infection recorded the highest percentage, 48.04% followed by Neoascaris vitulorum and Eimeria spp. (2) Percentage rates of parasitic infection (single, double or triple) in each animal were 62.80%, 29.43% and 7.77%, respectively. (3) Infection rate tended to increase with herd size in most cases. (4) Resource of water had highly significant effect on infection rate. (5) The highest infection was recorded in summer and the lowest in spring or winter. (6) A negative and highly significant correlation between infection and number of parasites (0.99). Herd size did not associate with infection, while temperature and relative humidity correlated significantly with infection rate (0.67 and 0.78) respectively.

Animal Husbandry↗
PubMed1996

Coccidial and helminth infections in goats kept indoors in the Netherlands.

An investigation was carried out on coccidial and helminth infections in goats kept indoors on five farms in the Netherlands. The goats were individually sampled. Coccidial oocysts were identified and nematode eggs counted. Larval cultures were made and infective larvae identified to the generic or species level. The goats were divided into three groups according to their age: kids, those weaned but not served, and older goats. Oocysts were found in 26 out of 27 kids (96.3%), in 52 out of 55 weaned but not served goats (94.5%), and in 72 out of 110 older goats (65.5%). Eimeria ninakohlyakimovae was the most common species in all groups with an overall prevalence of 82%, followed by Eimeria arloingi (78%) and Eimeria aspheronica (53.3%). Other species present were Eimeria alijevi (50%), Eimeria christenseni (39.3%), Eimeria caprina (38.7%), Eimeria hirci (28.7%) and Eimeria jolchijevi (7.3%). Nematode eggs were seen on four of the five farms. It appeared that on two farms some goats, although now kept indoors, had been on pasture in the past. These goats excreted low numbers of eggs of Ostertagia and/or Trichostrongylus, Strongyloides papillosus, Haemonchus contortus, Trichuris spp. and larvae of Muellerius capillaris. In goats that were kept exclusively indoors, infections with Strongyloides papillosus were found on two farms in the older group and on one farm also in the group weaned but not served. On two farms Skrjabinema ovis was incidentally observed by the farmer in older goats. This was confirmed by faecal examinations on one farm. All kids were free of nematode infection.

Animals↗
PubMed2006

Cross-sectional parasitological survey for helminth infections among fish farmers in Nghe An province, Vietnam.

A total of 964 adult fish farmers in five eastern districts in Nghe An province, Vietnam were investigated in late 2004 for food-borne trematodes and other helminth infections using duplicate Kato-Katz thick smears prepared from single stool samples. Eggs of fish-borne trematodes and of Fasciolopsis buski were found in 0.6 and 0.7% of farmers, respectively. Infection prevalences with soil-transmitted helminths (STHs), namely Ascaris lumbricoides, Trichuris trichiura and hookworm, were 34.8, 50.7 and 51.3%, respectively, and 81.8% were infected with at least one of the three STHs. While A. lumbricoides and T. trichiura were more prevalent in the eastern districts compared to the more western districts, the opposite was true for hookworm infections. The widespread prevalence of STH infections in fish farmers suggests that control of these infections in school-age children only may be inadequate. Identification of the human behavioural factors and environmental features responsible for the distribution and frequency of STHs among adults is needed as well as a sensitive diagnostic test of fish-borne trematodes at species level.

Adult↗
PubMed1996

Is the induction of apoptosis the mechanism of the protective effects of TNF alpha in helminth infection?

Tumour necrosis factor alpha has been implicated in protective immune responses to a number of parasitic helminths. However, the final effector mechanisms resulting in death or expulsion of the parasite are unclear. Here we suggest that, by employing phylogenetically conserved mechanisms, the mammalian immune system is able to interfere with helminth development directly and that the protective effects of TNF alpha in helminth infections may operate via the induction of parasite apoptosis.

Animals↗
PubMed1984

[Prevalence Of Intestinal Helminthic Infections And Skin Tests For Paragonimus And Clonorchis In Tuberculosis Patients]

This study was conducted to evaluate prevalence of intestinal helminthic infections and skin tests and Paragonimus and Clonorchis in tuberculosis(TB) patients in Korea. Stool examinations by formalin-ether technique and intradermal tests were carried out in 2 areas; Masan TB hospital and Kong-Ju TB hospital. 1. The positive rate of intestinal helminths of any kind was 51.7 % among 329 patients in Masan hospital, but 18.1 % among 215 patients in Kong-Ju hospital. 2. The infection rates of Trichocephalus trichiurus and Clonorchis sinensis were 20.7 % and 17.6 % respectively in Masan hospital patients, but the infection rates of T. trichiurus and C. sinensis were 6.5 % and 6.0 % respectively in Kong-Ju hospital patients. 3. In skin tests, positive reactions to Paragonimus and Clonorchis antigens were 22.0 % and 37.6 % respectively in Masan hospital patients. On the contrary, Kong-Ju hospital patients showed the positive rates of 15.2 % for Paragonimus and 27.2 % for Clonorchis respectively.

Journal Article↗
PubMed2000

Eosinophil granule proteins in serum and urine of patients with helminth infections and atopic dermatitis.

Eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin (EPX) are cytotoxic molecules involved in helminth infections and allergic reactions. Hitherto most clinical chemical studies have been concerned with the analysis of serum ECP in allergic diseases. The aim of this study was to examine whether serum as well as urine levels of these proteins are useful clinical chemical parameters in helminthiases and allergic diseases such as atopic dermatitis. Comparing these diseases under the same methodological conditions, levels of ECP and EPX were generally higher in helminthiases than in atopic dermatitis and non-helminth, non-allergic diseases. The highest levels of both proteins occurred in tropical worm diseases, in particular hookworm disease and onchocerciasis. When comparing helminthiases with allergic disorder, only hookworm disease (ECP and EPX) and onchocerciasis (EPX) exhibited significantly higher eosinophil cationic protein serum levels than atopic dermatitis. In patients with schistosomiasis mansoni and egg loads of > 1000-10 000 eggs/g stool (epg) EPX serum levels were significantly higher than in patients exhibiting loads < 1000 epg. Urinary analyses revealed only EPX to be present in measurable amounts. Levels of this protein were much higher in urine of patients with hookworm disease and onchocerciasis than in those with atopic dermatitis and in healthy controls. The results suggest that besides serum EPX, urinary EPX may be a useful clinical chemical parameter in eosinophilia of helminth and allergic aetiology.

Adolescent↗
PubMed2000

The potential of geographical information systems and remote sensing in the epidemiology and control of human helminth infections.

Geographic information systems (GIS) and remote sensing (RS) technologies are being used increasingly to study the spatial and temporal patterns of infectious diseases. For helminth infections, however, such applications have only recently begun despite the recognition that infection distribution patterns in endemic areas may have profound effects on parasite population dynamics and therefore the design and implementation of successful control programmes. Here, we review the early applications of these technologies to the major human helminths (geohelminths, schistosomes and the major lymphatic filarial worms), which demonstrate the potential of these tools to serve as: (1) an effective data capture, mapping and analysis tool for the development of helminth atlases; (2) an environment for modeling the spatial distribution of infection in relation to RS and environmental variables, hence furthering the understanding of the impact of density-independent factors in underlying observed parasite spatial distributions and their effective prediction; and (3) a focal tool in parasite control programming given their abilities to (i) better define endemic areas, (ii) provide more precise estimates of populations-at-risk, (iii) map their distribution in relation to health facilities and (iv) by facilitating the stratification of areas by infection risk probabilities, to aid in the design of optimal drug or health measure delivery systems. These applications suggest a successful role for GIS/RS applications in investigating the spatial epidemiology of the major human helminths. It is evident that further work addressing a range of critical issues include problems of data quality, the need for a better understanding of the population biological impact of environmental factors on critical stages of the parasite life-cycle, the impacts and consequences of spatial scale on these relationships, and the development and use of appropriate spatially-explicit statistical and modeling techniques in data analysis, is required if the true potential of this tool to helminthology is to be fully realized.

Animals↗