Giardiasis

Giardiasis Giardiasis is a diarrheal illness caused by Giardia intestinalis (also known as Giardia lamblia) The parasite is passed in the stool of an infected person or animal (both cysts & trophozoites) The parasite is protected by an outer shell that allows it to survive outside the body and in the environment for long periods of time During the past 2 decades, Giardia has become recognized as one of the most common causes of waterborne disease (drinking and recreational) in humans in the United States Very contagious

Symptoms Symptoms include Some may be asymptomatic diarrhea loose or watery stool foul-smelling stool stomach cramps upset stomach weight loss dehydration Some may be asymptomatic

Incubation Period & Duration Symptoms generally begin 1-2 weeks after being infected Duration Healthy persons, symptoms may last 2-6 weeks

How is Giardia spread? Swallowing recreational water contaminated with Giardia Eating uncooked food contaminated with Giardia Possibly found in soil, food, water, or surfaces contaminated with Giardia

Who is at risk? Everyone Persons at increased risk include: child care workers children who attend day care centers international travelers hikers, campers, swimmers people drinking or accidentally swallowing untreated water

Treatment Several prescription drugs are available Consult with your health care provider Giardia can infect all people Young children & pregnant women may be more susceptible Drink plenty of fluids while ill

Prevention Practice good hygiene Wash hands thoroughly with soap and water after using the toilet before handling or eating food after every diaper change Protect others by not swimming if experiencing diarrhea

Prevention Avoid food that might be contaminated Wash and/or peel all raw vegetables and fruits before eating Use uncontaminated water to wash all food that is to be eaten raw Avoid eating uncooked foods when traveling in countries with minimal water treatment and sanitation systems  Avoid fecal exposure during sex

Prevention Avoid water that might be contaminated Avoid swallowing recreational water Avoid drinking untreated water from ponds and streams Avoid using ice or drinking untreated water when traveling in countries where the water supply might be unsafe If you are unable to avoid drinking or using water that might be contaminated, then treat the water yourself by: Heating the water to a rolling boil for at least 1 minute You can pass Giardia in your stool and contaminate water for several weeks after your symptoms have ended

Infectious Diarrhea in Tourists Staying in a Resort Hotel EID January-February 1999, 5 (1) 168-171 British residents ill while staying at a hotel in Greece 6 lab confirmed cases of Giardia All stayed in the same hotel School sought advice about excluding a child with diarrhea 6 patients reported that many hotel guest were ill

Resort Hotel Outbreak EID January-February 1999, 5 (1) 168-171 British guests arrived at the hotel between May 22 and June 9 1997 Questionnaire administered by phone 86 booking groups 51 groups – 239 persons interviewed 224 ill while on holiday or within a few days of return 95% diarrhea Median duration of 13 days 82% stomach cramps 64% vomiting Median duration of 1 day 35 groups- 138 persons could not be contacted

Resort Hotel Outbreak EID January-February 1999, 5 (1) 168-171 224 ill DEFINITE cases - lab confirmed 70 (31%) PROBABLE cases – no pathogen identified but had diarrhea lasting 4 or more days 107 (48%) POSSIBLE cases – no pathogen identified but had diarrhea lasting less than 4 days

Table 1: Pathogens identified in DEFINITE cases No. of definite casesa (%) Giardia lamblia 58 (83) Cryptosporidium parvum 11 (16) Campylobacter spp. 4 (6) Salmonella spp. 3 (4) Entamoeba histolytica 2 (3) Rotavirus 1 (1) * Sum exceeds 70 because of co-infections

Figure 1. Epidemic curve for diarrhea, by category of case

Figure 2. Interval between arrival at hotel and onset of illness (vomiting or diarrhea), by category of case

Resort Hotel Outbreak EID January-February 1999, 5 (1) 168-171 Telephone interviews – 54 reports 32 (59%) identified problems with food Tasted strange Inadequately cooked or heated Left out uncovered 27 (50%) identified problems with room water Sewage smell Discoloration (around June 4) 7 (13%) identified problems with drinks reconstituted with tap water

Resort Hotel Outbreak EID January-February 1999, 5 (1) 168-171 Significantly associated with illness Consumption of reconstituted orange juice Consumption of raw vegetables and salads Reports of problems with water in the hotel room

Resort Hotel Outbreak EID January-February 1999, 5 (1) 168-171 2 Principal illnesses due to sewage contamination of the water supply Viral gastroenteritis outbreak Giardiasis outbreak

Resort Hotel Outbreak EID January-February 1999, 5 (1) 168-171 Point-source Lab confirmation 129 guests reported that their room water smelled of sewage or was discolored around June 4 (mostly from definite cases) All avoided tap water a. Consumption of reconstituted orange juice Water supply was chlorinated but not filtered at certain points within the hotel