Giardiasis Outbreak Associated with Asymptomatic Food Handlers in New York State, 2015

Abstract

Giardia duodenalis is a protozoan that causes a gastrointestinal illness called giardiasis. Giardiasis outbreaks in the United States are most commonly associated with waterborne transmission and are less commonly associated with food, person-to-person, and zoonotic transmission. During June to September 2015, an outbreak of 20 giardiasis cases occurred and were epidemiologically linked to a local grocery store chain on Long Island, New York. Further investigation revealed three asymptomatic food handlers were infected with G. duodenalis , and one food handler and one case were coinfected with Cryptosporidium spp. Although G. duodenalis was not detected in food samples, Cryptosporidium was identified in samples of spinach dip and potato salad. The G. duodenalis assemblage and subtype from one of the food handlers matched two outbreak cases for which genotyping could be performed. This outbreak highlights the potential role of asymptomatically infected food handlers in giardiasis outbreaks.

Detection of human intestinal protozoan parasites in vegetables and fruits: a review

“…The outbreaks of giardiasis have also been associated with a variety of processed foods. Human infections of G. duodenalis are often associated with the consumption of contaminated raw vegetables and fruits [39][40][41].…”

Risk factors for sporadic giardiasis: a systematic review and meta-analysis

“…Not washing hands before meals or during food preparation is a risk factor. A recent outbreak underscores the risk associated with asymptomatic food handlers (Figgatt et al, 2017). It is essential to highlight that this meta-analysis shows the importance of the recommendation of washing vegetables and washing hands before eating or before preparing food.…”

A scoping review of risk factors and transmission routes associated with human giardiasis outbreaks in high-income settings

“…The contaminated food became the primary transmission route for the outbreak. In another outbreak, no individual food item was identified; the assemblage and subtype from one of the asymptomatic food handlers matched the two outbreak cases for which genotyping was available ( Figgatt et al., 2017 ). An outbreak among UK tourists residing at a hotel in Greece was linked to a number of risk factors, including the consumption of raw vegetables ( Hardie et al., 1999 ).…”