Giardia Outbreak in Western Kentucky

Public health officials from the Hopkins County Health Department, Kentucky Department for Public Health, and the Centers for Disease Control and Prevention (CDC) are investigating an outbreak of Giardia, primarily occurring in Hopkins County, Kentucky. As of July 21, 2025, a total of 66 laboratory-confirmed cases of Giardia have been reported in Hopkins, Muhlenberg and Webster Counties since May. Although the specific sources of infection are unknown, many cases have reported dining at El Tapatio Mexican Cantina in Madisonville, Kentucky. The restaurant has fully cooperated with health officials in response to the investigation. Health officials continue to conduct environmental sampling to help identify potential sources of Giardia exposure.

Giardia is a parasite that naturally occurs in untreated waters, such as streams, rivers and lakes. The parasite spreads easily from one person to another through contaminated water, food or other surfaces. Symptoms of Giardia typically occur one to three weeks after exposure. Common symptoms include diarrhea, gas, nausea, stomach pain and fatigue and can last several weeks. Some people, such as young children, pregnant women and those with weakened immune systems, are at higher risk for dehydration or other complications.

To diagnose giardiasis, the infection caused by Giardia, CDC recommends collecting three stool samples over several days. Microscopy with direct fluorescent antibody (DFA) testing is the gold standard for diagnosing giardiasis. Illnesses caused by Giardia should be reported by health care providers and laboratories to the local health department where the patient resides within one business day of identification.

The Giardia parasite is protected by an outer shell called a cyst and can survive outside the body for long periods of time. People with Giardia infections can shed the cysts in their feces for several weeks and infect others. To prevent and control Giardia outbreaks, CDC recommends prompt diagnosis, maintaining good hand hygiene, cleaning and disinfecting home environments and child care facilities and monitoring water quality in private wells.

Approximately 100 to 300 cases of Giardia occur in Kentucky each year. Giardia occurs more frequently during summer and early fall and is often linked to recreational water sources, like lakes, rivers, and swimming pools. Anyone who is concerned that they may have Giardia should talk to their healthcare provider about testing or treatment options. People with diarrhea should not work in food service or healthcare settings, attend daycare or participate in recreational water activities, such as swimming or splash pads, until diarrhea is resolved.