The primary symptoms of giardiasis include loss of appetite, diarrhea, watery stools, cramps, upset stomach, bloating, gas and burping. Some also suffer from projectile vomiting although it is fairly uncommon. It is important to note that most people are asymptomatic to giardiasis and only about a third of those infected exhibit any symptoms. The incubation period for the disease is nine to fifteen days. If left untreated, the symptoms can last up to six weeks or more.
Giardia infection is a waterborne disease. The parasite that causes it can be found in streams, lakes, municipal water supplies, swimming pools, whirlpool and wells. Water can become contaminated from wastewater discharge, animal feces or agricultural runoff. Sometimes, children and adults suffering from diarrhea can also accidentally contaminate pools and spas.
Giardiasis can also be spread through food. Food handlers infected with giardiasis and who don’t wash their hands thoroughly can transmit it. Raw produce that is irrigated or washed with contaminated water may also cause it.
In addition, it can be transmitted through person-to-person contact. Hands can become contaminated with fecal matter (this can happen when changing a child’s diaper for example). Childcare workers and children in child care centers are often more at risk. Giardiasis can also be transmitted through anal sex.
While there are drugs that effectively treat giardiasis, your best defence is prevention. There are some segments that are at higher risk of becoming infected with the giardia parasite. These include people who are traveling to areas with poor sanitation, people without access to safe drinking water and people who have anal sex and children.
For travellers it is generally advisable to avoid eating or drinking the following to help reduce their chances of getting giardia infection. These include:
- tap water
- raw or undercooked meat
- fruit that has already been peeled
- mayonnaise or sauces
When traveling, it is generally believed that sealed bottled water, tea, coffee and alcohol may be safe to drink. It might be in the interest of travelers to avoid swimming in water that may be contaminated with giardia.