Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017536 (giardiasis)
 1,714 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Our objective was to determine the prevalence of intestinal protozoa in homosexual men attending a sexually transmitted diseases (STD) clinic, to compare it with the prevalence in a previous study from the same clinic, and to examine the relationship, if any, between the presence of protozoa and sexual practices. Men who consecutively attended the clinic and who gave a history of having had recent sexual contact with another male were invited to provide a stool sample for protozoological examination. Diarrhoeal samples were examined by direct microscopy for trophozoites and cysts and, after staining, for Cryptosporidium spp. In all cases, a modified formol-ether method was used to concentrate protozoal cysts before microscopy. One hundred and seventy-five of the 257 men invited to participate in the study provided a stool sample. At least one species of protozoan was found in 99 (57%) men. Giardia intestinalis was identified in only 5 (3%) men. Blastocystis hominis was found in 46 (26%) men, but the presence of this protozoan was not associated with diarrhoea. Other than the prevalence of Entamoeba dispar/histolytica and G. intestinalis, which remained unchanged, the proportion of men who harboured the non-pathogenic protozoa was significantly increased from 1981/82. A correlation between oral-anal sex or peno-insertive or peno-receptive anal intercourse and the prevalence of protozoa was not found. There was also no correlation between the number of species of protozoa carried and these sexual practices. The presence of protozoa was not associated with a history of foreign travel or sexual contact with a man who had recently travelled outside the UK. The study showed that, although the prevalence of infection is low, giardiasis is still transmissible amongst homosexual men. A correlation between individual sexual practices and the prevalence of intestinal protozoa was not found.
Int J STD AIDS 1999 Dec
PMID:Intestinal protozoa in homosexual men in Edinburgh. 1063 57

Human-parasite relationships have played an essential role in the emergence or re-emergence of some parasitic diseases. These interactions are due to numerous causes. Some are linked to humans (immunodeficiencies due to AIDS among other causes, treatments, nosocomial contaminations, genetic predisposition), others concern the parasite (particular genotypes having modified their parasitic specificity). Several of these causes were predominant in the emergence of parasitoses such as cryptosporidiasis, microsporidioses or, to a certain point, pneumocystosis, the transmission of which has become zoonotic or even anthroponotic, inter-human. Re-emergent diseases (toxoplasmosis, leishmaniasis, giardiasis, strongyloidiasis, scabies) had already been described in human pathology, but their frequency or symptomatology have been drastically modified. In this case also, the unbalanced host-parasite relationship is largely responsible but it can not be dissociated from other causes, especially environmental and nutritional.
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PMID:Emerging parasite zoonoses: the role of host-parasite relationship. 1111 61

A case of metronidazole- and albendazole-resistant giardiasis in a patient with the acquired immunodeficiency syndrome was successfully treated with nitazoxanide (1.5 g twice a day for 30 days). Animal studies and in vitro assays showed that the isolate was resistant to both metronidazole and albendazole and susceptible to nitazoxanide.
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PMID:Successful treatment of metronidazole- and albendazole-resistant giardiasis with nitazoxanide in a patient with acquired immunodeficiency syndrome. 1136 Feb 22

The use of clarithromycin in preventing Mycobacterium avium complex (MAC) may also prevent a number of other opportunistic infections in AIDS patients. A large multinational study showed a reduction in Pneumocystis carinii pneumonia (PCP), community-acquired pneumonia (CAP), and giardiasis, an intestinal disorder. The study involved participants with CD4 counts below 100.
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PMID:Clarithromycin for MAC prevention offers additional benefits. 1136 31

Giardia lamblia is one of the most common parasitic infections. Although standard treatments are usually curative, some immunocompromised patients, including patients with acquired immunodeficiency syndrome as well as healthy patients, have giardiasis that is refractory to recommended regimens. We report our experience with 6 patients with giardiasis, for whom therapy with a combination of quinacrine and metronidazole resulted in cures for 5 of the 6 patients.
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PMID:Treatment of patients with refractory giardiasis. 1138 90

Diarrhea due to intestinal microbial infections is a frequent manifestation among HIV-infected patients. It has been postulated that HIV-infected patients may have special types of intestinal infections, and that immune activation from such parasites may affect the progression of HIV disease. To evaluate these associations, the frequency of infections was examined in HIV-infected patients in Bahia, Brazil. To determine the potential impact of the presence of intestinal parasitic infections on HIV disease progression, a retrospective study approach was used. The medical charts of 365 HIV-infected patients who had been treated at the AIDS Clinic of the Federal University of Bahia Hospital were reviewed, and the prevalence of parasites was compared with 5,243 HIV-negative patients who had attended the hospital during the same period of time. Among HIV-infected subjects, CD(4) count, RNA plasma viral load (VL), and number of eosinophils were compared according to their stool examination results. The overall prevalence of each parasite was similar for HIV-positive and HIV-negative patients. However, the prevalence of S. stercoralis (p<10(-7)) and G. lamblia (p=0.005) was greater for HIV-infected subjects. The mean CD(4) count and viral load of HIV patients in our clinic who had stool examinations was 350 cells +/- 340 and 4.4 +/- 1.4 log RNA viral load, respectively. In this patient group there was no clear association between the level of the absolute CD(4) count or the viral load and a specific parasitic infection. The presence of an intestinal parasitic infection was not associated with faster progression of the HIV disease among HIV-infected patients. We conclude that strongyloidiasis and giardiasis are more frequent in HIV-infected patients in Bahia, Brazil. If this association is due to immune dysregulation, as has been proposed elsewhere, it must occur in patients after only minor shifts in CD(4) count from normal levels, or as a result of immune dysfunction not represented by CD(4) count. These infections do not appear to alter the progression of HIV disease.
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PMID:High prevalence of giardiasis and stronglyloidiasis among HIV-infected patients in Bahia, Brazil. 1201 May 98

Many classes of pathogens excreted in feces are able to initiate waterborne infections. There are bacterial pathogens, including enteric and aquatic bacteria, enteric viruses, and enteric protozoa, which are strongly resistant in the water environment and to most disinfectants. The infection dose of viral and protozoan agents is lower than bacteria, in the range of one to ten infectious units or oocysts. Waterborne outbreaks of bacterial origin (particularly typhoid fever) in the developing countries have declined dramatically from 1900s. Therefore, some early bacterial agents such as Shigella sonnei remains prevalent and new pathogens of fecal origin such as zoonotic C. jejuni and E. coli O157:H7 may contaminate pristine waters through wildlife or domestic animal feces. The common feature of these bacteria is the low inoculum (a few hundred cells) that may trigger disease. The emergence in early 1992 of serotype O139 of V. cholerae with epidemic potential in Southeast Asia suggests that other serotypes than V. cholerae O1 could also getting on epidemic. Some new pathogens include environmental bacteria that are capable of surviving and proliferating in water distribution systems. Other than specific hosts at risk, the general population is refractory to infection with ingested P. aeruginosa. The significance of Aeromonas spp. in drinking water to the occurrence of acute gastroenteritis remains a debatable point and has to be evaluated in further epidemiological studies. Legionella and Mycobacterium avium complex (MAC) are environmental pathogens that have found an ecologic niche in drinking and hot water supplies. Numerous studies have reported Legionnaires' disease caused by L. pneumophila occurring in residential and hospital water supplies. M. avium complex frequently causes disseminated infections in AIDS patients and drinking water has been suggested as a source of infection; in some cases the relationship has been proven. More and more numerous reports show that Helicobacter pylori DNA can be amplified from feces samples of infected patients, which strongly suggests fecal-to-oral transmission. Therefore, it is possible that H. pylori infection is waterbome, but these assumptions need to be substantiated. Giardiasis has become the most common cause of human waterborne disease in the U.S. over the last 30 years. However, as a result of the massive outbreak of waterborne cryptosporidiosis in Milwaukee, Wisconsin, affecting an estimated 403,000 persons, there is increasing interest in the epidemiology and prevention of new infection disease caused by Cryptosporidium spp. as well as monitoring water quality. The transmission of Cryptosporidium and Giardia through treated water supplies that meet water quality standards demonstrates that water treatment technologies have become inadequate, and that a negative coliform no longer guarantees that water is free from all pathogens, especially from protozoan agents. Substantial concern persists that low levels of pathogen occurrence may be responsible for the endemic transmission of enteric disease. In addition to Giardia and Cryptosporidium, some species of genera Cyclospora, Isospora, and of family Microsporidia are emerging as opportunistic pathogens and may have waterborne routes of transmission. More than 15 different groups of viruses, encompassing more than 140 distinct types can be found in the human gut. Some cause illness unrelated with the gut epithelium, such as Hepatitis A virus (HAV) and Hepatitis E virus (HEV). Numerous large outbreaks have been documented in the U.S. between 1950 and 1970, and the incidence rate has strongly declined in developing countries since the 1970s. Hepatitis E is mostly confined to tropical and subtropical areas, but recent reports indicate that it can occur at a low level in Europe. A relatively small group of viruses have been incriminated as causes of acute gastroenteritis in humans and fewer have proven to be true etiologic agents, including rotavirus, calicivirus, astrovirus, and some enteric adenovirus. These enteric viruses have infrequently been identified as the etiologic agents of waterborne disease outbreaks, because of inadequate diagnostic technology, but many outbreaks of unknown etiology currently reported are likely due to viral agents. Actually, Norwalk virus and Norwalk-like viruses are recognized as the major causes of waterborne illnesses world-wide. The global burden of infectious waterborne disease is considerable. Reported numbers highly underestimate the real incidence of waterborne diseases. The most striking concern is that enteric viruses such as caliciviruses and some protozoan agents, such as Cryptosporidium, are the best candidates to reach the highest levels of endemic transmission, because they are ubiquitous in water intended for drinking, being highly resistant to relevant environmental factors, including chemical disinfecting procedures. Other concluding concerns are the enhanced risks for the classic group of debilitated subjects (very young, old, pregnant, and immunocompromised individuals) and the basic requirement of to take specific measures aimed at reducing the risk of waterborne infection diseases in this growing, weaker population.
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PMID:Microbial agents associated with waterborne diseases. 1254 97

A cross sectional survey was conducted to determine the association between enteric parasites and diarrhoea in HIV-infected adults in Caracas. Three hundred and four patients were evaluated: 104 had acute diarrhoea, 113 chronic diarrhoea and 87 were controls. Isopora belli infection was associated with acute (P = 0.022) and chronic diarrhoea (P = 0.003), Entamoeba histolytica/dispar infection was also associated with both acute (P = 0.015) and chronic diarrhoea (P = 0.017). Strongyloides stercoralis (P = 0.003), and Cryptosporidium parvum (P = 0.017) infections were associated mainly with chronic episodes. Weight loss (P < 0.001), a non-infectious factor investigated, was significantly associated with diarrhoea. Eosinophilia, a laboratory parameter studied, was found to be associated with strongyloidiasis (P = 0.001), giardiasis (P = 0.001) and isoporiasis (P = 0.003). In summary, the presence of enteric parasites in HIV-infected patients from tropical urban areas with diarrhoea, with or without significant weight loss, must be considered. Similarly, eosinophilia might suggest parasitic infection in these patients.
Int J STD AIDS 2003 Jul
PMID:Association between parasitic intestinal infections and acute or chronic diarrhoea in HIV-infected patients in Caracas, Venezuela. 1286 31

Almost all children living in endemic zones are infected by gastrointestinal parasites. However only 3 to 5% develop diarrhea directly related to parasite infection. Entamoeba hystolytica and Entamoeba dispar coexist in many areas. In the past Entamoeba dispar was called non-pathogenic ameba. The vegetating forms are microscopically identical and detection of wall differences using biochemical tests is unreliable. Thus since it is rarely possible to determine whether or not a vegetating ameba found in stools is hematophagous treatment using metronidazole is the only alternative. Failure of such treatment indicates that dysentery is probably due to a cause other than amibiasis, e.g., bacterial infection in most cases. Another protozoan commonly found in endemic areas is Giardia. Giardia can cause diarrhea and this is frequently the case in undernourished children. Giardia infection leads to severe atrophic villosity requiring appropriate specific treatment. In children cryptosporidioses may be asymptomatic or lead to diarrhea especially in cases associated with malnutrition or immunodeficiency related in particular to AIDS. Helminths are a rare cause of significant diarrhea except Anguillula in undernourished children. In children presenting severe malnutrition, anguilluliasis can lead to serious consequences and requires immediate treatment using ivermectin. To avoid severe diarrhea in children presenting immunodeficiency induced by corticotherapy or chemotherapy for cancer, prophylaxis is mandatory against anguilluliasis using ivermectin and usually against giardiasis using metronidazole.
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PMID:[Parasitic diarrhea in eutrophic and malnourished children]. 1476 99

Nitazoxanide (Alinia, Romark Laboratories) was synthesized based on the structure of niclosamide. In vitro studies have demonstrated activity against a broad range of parasites as well as some bacteria. Three controlled trials demonstrated efficacy in cryptosporidiosis, however, the efficacy in advanced AIDS patients (CD4 cell counts = 50) at approved doses was limited. Trials have also demonstrated efficacy comparable to metronidazole (Flagyl, GD Searle and Co.) in giardiasis with fewer side effects. Nitazoxanide is also effective versus intestinal helminths and tapeworms as well as in chronic fascioliasis. Side effects in clinical trials have been similar to placebo. Nitazoxanide is the first agent proven to be effective in cryptosporidiosis. It has also proven efficacy in giardiasis. Nitazoxanide is efficacious again intestinal helminths. Additional indications may be developed in the future.
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PMID:Nitazoxanide: a new broad spectrum antiparasitic agent. 1548 70


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