Giardia lamblia infection

Kamda JD, Singtr SM. Phosphoinositide-3 kinase-dependent inhibition of dendritic cell interleukin-12 production by giardia lamblia. Infect Immirn. 2009 77 685-93. 

Like Ascariasis, Giardia lamblia infections may impair vitamin A absorption when the vitamin is administered to children in an oily (Katsampes et al.y 1944) or aqueous (Mahalanabis et al., 1979) form. The mechanism by which intestinal parasites may decrease absorptive efficiency is not by way of fat malabsorption (Sivakumar and Reddy, 1975 Mahalanabis et al.y 1979) it may be due to alterations in the structure integrity of the mucosa, intestinal motility, or both. Also possible is the secretion of toxic irritants by the parasites, causing inflammatory reactions in the submucosa (Sheehy et al.y 1962). 

Bacteria are likely precipitants in many other cases including Escherichia coli, Salmonella species, Shigella species, Vibrio cholerae, and Clostridium difficile. The term dysentery has often been used to describe some of these bacterial infections when associated with serious occurrences of bloody diarrhea. Additionally, acute diarrheal conditions can be prompted by parasites-protozoa such as Entamoeba histolytica, Microsporidium, Giardia lamblia, and Cryptosporidium parvum. Most of these infectious agents can be causes of traveler s diarrhea, a common malady alflicting travelers worldwide. It usually occurs during or just after travel subsequent to the ingestion of fecally-contaminated food or water. It has an abrupt onset but usually subsides within 2 to 3 days. 

A bacterial enteric infection may manifest as diarrhea or may also remain asymptomatic. Recently, it was recognized that even asymptomatic enteric infections by Cryptosporidium, EAggEC and Giardia lamblia may be associated with nutritional shortfalls, even in the absence of overt diarrheal illness [17]. 

Giardiasis For the treatment of giardiasis caused by Giardia duodenalis (also termed Giardia lamblia) in adults and pediatric patients older than 3 years of age. Trichomoniasis For the treatment of trichomoniasis caused by Trichomonas vaginalis in female and male patients. Because trichomoniasis is a sexually transmitted disease with potentially serious sequelae, partners of infected patients should be treated simultaneously in order to prevent reinfection. 

Giardia lamblia 7 days Diarrhea which can last 1-2 weeks Dose >1 cysts Sewage, manure, wild and domestic animals, infected food handlers and water... 

The answer is e. (Hardman, pp 995-998.) Metronidazole is a low-molecular-weight compound that penetrates all tissues and fluids of the body. Metronidazole s spectrum of activity is limited largely to anaerobic bacteria—including B./ragilis—and certain protozoa. It is considered to be the drug of choice for trichomoniasis in females and carrier states in males, as well as intestinal infections with Giardia lamblia. 

It is a nitroimidazole. It has a broad spectrum of protozoal and antimicrobial activity. It shows antibacterial action against all anaerobic cocci, anaerobic gram negative bacilli including bacteroides species and anaerobic spore forming gram positive bacilli. It is very effective in infections due to Entamoeba histolytica, Giardia lamblia and Trichomoniasis. It also causes radio-sensitization. 

Other protozoal infection is giardiasis which is caused by Giardia lamblia and the drug of choice in its treatment are imidazole derivatives. 

Reiner, D.S., Wang, C.-S., Gillen, F.D. 1986. Human milk kills Giardia lamblia by generating toxic lipolytic products. J. Infect. Dis. 154, 825-832. 

Edlind TD, Hang TL, Chakraborty PR. Activity of the anthelmintic benzimidazoles against Giardia lamblia in vitro. J Infect Dis 1990 162(6) 1408-11. 

Garlic has in vitro activity against Entamoeba histolytica, Giardia lamblia, Leishmania major, Leptomonas colsoma, and Crithidia fasciculate (40,47). In vivo and clinical data is needed before garlic can be used for treatment of infections with these organisms. 

In the other group, all the patients have been adults with a history of susceptibility to infection commencing between 19 and 29 years of age. These patients have presented with diarrhea, some evidence of malabsorption, and infestation with Giardia lamblia. Jejunal biopsy and radiology have revealed nodular lymphoid hyperplasia (H16). This syndrome is also seen with severe hypogammaglobulinemia in surviving adults (K4). Cases with isolated IgA deficiency where the absence of isoagglutinins has raised a suspicion of inadequate IgM are also described. 

Opportunistic infections bacterial (MAI, TB) viral (CMV, herpes) fungal Candida albicans, cryptococcus) protozoal Pneumocystis carinii, microsporidia, Isospora belli, Cryptosporidia, Giardia lamblia) Malignancies Kaposi s sarcoma, lymphoma Medications antibiotics, anticancer chemotherapy, antidepressants Neuropsychiatric disorders dementia, depression, anxiety, encephalopathy Socioeconomic factors IV drug abuse, low income... 

Answer C. In amebic dysentery caused by Entamoeba histolytica and GI infections with diarrhea ( back-packer s diarrhea ) due to Giardia lamblia, metronidazole is the drug of choice. Diloxanide is a backup drug for noninvasive intestinal amebiasis, but it has minimal activity in giardial infections. Quinacrine has effectiveness in giardiasis but not amebiasis. TMP-SMX has antiprotozoal effectiveness in Pneumocystis carinii pneumonia. Ciprofloxacin is devoid of antiprotozoal activity. 

Carranza PG, Lujan HD. New insights regarding the biology of Giardia lamblia. Microbes Infect. 2010 12 71-80. 

Berberine possesses antimicrobial activity against bacterial [13, 94-96], fungal [97], protozoan [98, 99], and viral [100-102] infections. In vitro studies have shown that berberine is effective against Entamoeba histolytica, Giardia lamblia, Trichomonas vaginalis [98, 103], Candida spp. [97, 104], Plasmodium falciparum [99], Staphylococcus aureus [95, 105, 106], influenza virus [100], human immunodeficiency virus (HIV) [107], human cytomegalovirus [101], herpes simplex virus, [102] Chlamydia trachomatis [105], Helicobacter pylori [96], and Leish-mania donovani [99]. 

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