Giardia outbreak associated with a roadside spring in Rensselaer County, New York.

Area of Science:

• Public Health
• Environmental Health
• Infectious Disease Epidemiology

Background:

• An increase in Giardia duodenalis cases was observed in Rensselaer County in September 2009.
• Initial epidemiological investigations suggested a potential link to a local roadside spring.

Purpose of the Study:

• To investigate the source of the Giardia duodenalis outbreak.
• To confirm the contamination of the roadside spring and implement control measures.

Main Methods:

• Epidemiological investigation to identify the source of illness.
• Site visit by environmental health staff to assess the roadside spring.
• Collection and laboratory analysis of water samples from the spring for Giardia cysts.

Main Results:

• The epidemiological investigation identified a roadside spring as a probable source.
• Water samples from the spring tested positive for empty Giardia cysts.
• 36 laboratory-confirmed Giardia cases were identified in New York and Massachusetts residents.

Conclusions:

• The roadside spring was confirmed as the source of the Giardia duodenalis outbreak.
• Preventive measures were implemented, including the destruction of the contaminated spring.
• The outbreak highlights the importance of monitoring environmental sources for waterborne pathogens.