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Prevent Illness. Diagnosis and Treatment. Diagnosis and Treatment Information for Medical Professionals. To receive updates about giardiasis and other waterborne diseases, enter your email address: Email Address. What's this? Links with this icon indicate that you are leaving the CDC website. You could have to submit more samples during treatment. Your doctor may also perform an enteroscopy. This procedure involves running a flexible tube down your throat and into your small intestine.
This will allow your doctor to examine your digestive tract and take a tissue sample. In most cases, giardiasis eventually clears up on its own. Your doctor might prescribe medication if your infection is severe or prolonged. Most doctors will recommend treatment with antiparasitic drugs, rather than leaving it to clear up on its own. Certain antibiotics are commonly used to treat giardiasis:. Giardiasis can lead to complications such as weight loss and dehydration from diarrhea.
The infection can also cause lactose intolerance in some people. Children under 5 years old who have giardiasis are at risk for malnutrition , which can interfere with their physical and mental development.
Ponds, streams, rivers, and other bodies of water can all be sources of giardia. Bring bottled water with you when you go hiking or camping. You should also avoid brushing your teeth with tap water.
Keep in mind that tap water can also be present in ice and other beverages. Avoid eating uncooked local produce. Be cautious about sexual practices associated with the spread of this infection, such as anal sex. Use a condom to reduce the chance of contracting giardiasis. Giardiasis infections usually last about six to eight weeks, but problems such as lactose intolerance can persist after the infection clears up.
In addition, as a tetraploid organism, Giardia would be expected to develop resistance much more slowly than haploid organisms.
Therefore, it is more accurate to refer to treatment failure or clinical resistance. A few reports have addressed the treatment of patients with refractory giardiasis. In one report, six patients had giardiasis lasting from 6 months to over one year and had already failed one or more treatment courses that included metronidazole.
Five of the 6 patients were successfully treated with the combination of metronidazole and quinacrine In a large water-borne outbreak of giardiasis in Norway there were 38 out of cases that were considered refractory to metronidazole These 38 patients were treated with a progressive approach using one week of albendazole plus metronidazole, followed by paromomycin for those failing the first regimen and three weeks of quinacrine plus metronidazole for those failing the second regimen.
Thirty responded to metronidazole plus albendazole. Six of the 8 failures were treated with paromomycin and 3 responded. The remaining 3 were treated with quinacrine plus metronidazole and all responded. These studies suggest that combination therapy with metronidazole and albendazole or quinacrine will be successful in most cases of treatment failure.
In addition to documented treatment failures, many people have persistent symptoms after presumably successful treatment of giardiasis, which could be due to inability to find Giardia in fecal samples or altered intestinal anatomy or function after diarrhea. A study of the above-noted outbreak of giardiasis in Norway revealed that some people had persistent symptoms, but negative fecal samples. The lack of an outcome difference between the two groups suggested that the persistence of symptoms was not due to cryptic giardiasis.
Instead, these patients had an illness consistent with irritable bowel syndrome, an entity that is common after a variety of gastrointestinal infections. Patients with laboratory proven giardiasis from the same outbreak had a prevalence of Pregnancy: Pregnancy poses a significant complication for the treatment of giardiasis, since few of the available agents are known or presumed to be safe during early pregnancy.
The benzimidazoles mebendazole and albendazole are embryotoxic in animals during organogenesis although at levels higher than obtained with these drugs in humans.
The nitromidazoles metronidazole, tinidazole, secnidazole, ornidazole are mutagenic in bacteria, so acceptance of these agents during pregnancy has been very slow. However, metronidazole has subsequently been evaluated in multiple studies during second and third trimesters of pregnancy for treatment of bacterial vaginosis or trichomoniasis, including some showing improved outcome when patients with symptomatic vaginosis at risk for premature delivery were treated , These agents are overall, the most efficacious for treating giardiasis and appear reasonable to use during the second and third trimesters for symptomatic giardiasis, especially since the nutritional consequences of giardiasis may outweigh any as yet theoretical risk of these drugs.
However, paromomycin, a nonabsorbed aminoglycoside is often recommended during pregnancy, especially when the disease is mild or asymptomatic. A lactase free diet can be tried during treatment and shortly after, because deficiency of disaccharidases can occur due to damage to the brush border. Lactase deficiency during giardiasis is very common , , and enzyme deficiency may persist for weeks to months.
Therefore, elimination of lactose from the diet is commonly recommended for patients with giardiasis. Antidiarrheal drugs may be used but are usually not necessary. Likewise, oral rehydration solution or intravenous fluid administration is advised for volume depletion, but that rarely occurs with giardiasis.
Probiotics have been studied for the treatment and prevention of a number of intestinal pathogens because of the known effect of probiotics on gastrointestinal flora. These probiotic agents have not been approved by the FDA so there is no standardization in the US, and those who choose to use them must obtain them from health food stores. When resolution of symptoms is achieved in individual patients, repeat stool specimens are not required.
Treatment failure that is documented by persistence of parasites may be the result of drug resistance, but true drug resistance has not been clinically correlated with treatment failures, perhaps because of the difficultly in adapting the organisms to in vitro cultivation.
Whether asymptomatic carriers should be treated remains controversial, but probably depends on the setting. Treatment of asymptomatic carriers in non-endemic areas may prevent symptomatic cases, but reinfection occurs so frequently in some endemic regions that asymptomatic carriers should not be treated.
Carriers of who work in day care centers or in food preparation should have documentation of parasitologic cure by stool specimens. When there is reason to suspect cross-infection in a family, all carriers in the family should be treated till parasitological cure is documented.
Vaccines for humans are not available, but a commercial Giardia vaccine is available in the USA for dogs and cats in preventing clinical symptoms and reduction of cyst shedding. It protected dogs and cats from infection when orally challenged with Giardia lamblia derived from a symptomatic human source Whether the vaccine is prevents naturally occurring infection has not been determined. The vaccine has also been proposed as an immunotherapeutic agent for persistently infected animals but subsequent studies have not demonstrated efficacy for this purpose 11 , Since Giardia is transmitted via a fecal-oral route, prevention efforts should be directed at interrupting these routes of transmission.
One of the most frequent means of acquisition of infection is by ingestion of contaminated water, typically from fresh water streams or shallow wells. Since cysts remain viable for longer at lower temperatures, the risk is sometimes higher in colder climates. Iodine or chlorine treatment also has activity against the cysts, but is much less effective for Giardia than for most bacterial or viral pathogens, requiring more prolonged exposure.
Food is a much less frequent source, but outbreaks have been associated with infected food handlers. These infections are difficult to prevent, but uncooked foods should be avoided in endemic areas. In developed countries, direct fecal-oral transmission occurs most frequently in settings where small children are cared for; these infections can be reduced by good handwashing techniques and appropriate use of gloves.
Male homosexual activity has been documented as a means of transmission of giardiasis, and female: female sexual transmission has been documented for Entamoeba histolytica, which has a similar mechanism of transmission Presumably, these occur by direct fecal-oral contact, and may not be prevented by the usual barrier methods. Household pets are usually infected by non-human genotypes of G. Adam RD.
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