Cyclospora Foodborne Disease 2015 PDF

PUBH 4104 Foodborne Disease Protozoan Infections Cyclospora 1 Cyclospora Philadelphia, Pennsylvania, June 2000 – Wedding reception – 1 to 7 days later, diarrhea and other GI illnesses – 83 attendees, 54 showed symptoms that met the case definition for...

PUBH 4104 Foodborne Disease Protozoan Infections Cyclospora 1 Cyclospora Philadelphia, Pennsylvania, June 2000 – Wedding reception – 1 to 7 days later, diarrhea and other GI illnesses – 83 attendees, 54 showed symptoms that met the case definition for cyclosporiasis – Raspberry cream filling in the wedding cake had DNA fragments from Cyclospora cayetanensis Only species of Cyclospora known to cause disease in humans 2 The Usual Suspects 3 Cyclospora Background Spring/Summer 1996 – 1465 cases of cyclosporiasis in North America 20 US States 2 Canadian Provinces 1997 – 1600 cases in North America Strawberries were implicated first before raspberries were found to be the major culprit Cyclospora infection was virtually unknown in North America before this. 4 Cyclospora Background In order to continue export of product to the United States in 1996, Guatemalan Farms were required to improve: – Water quality – Employee hygiene – Sanitary conditions 5 Cyclospora Background In 1997 further outbreaks associated with raspberries occurred in April It was the end of May before the USA suspended the importation of Guatemalan raspberries Also outbreaks associated with; – Mesclun (AKA spring mix, mixed baby lettuce or field greens) – Fresh basil (outbreaks in British Columbia and Toronto) – Fresh snow peas 6 Cyclospora Background Canada did not put restrictions in place on the importation of product from Guatemala – 1998 in Toronto over 300 people became ill from raspberries – 1999 saw several outbreaks of cyclosporiasis, Guatemalan blackberries were suggested to be the cause, but not proven, in two outbreaks – In 2000 there were other outbreaks, two of them had Guatemalan raspberries implicated as the source 7 Cyclospora Background How the berries are contaminated is not known but possibilities include: – Fecal contamination of water used to spray fruit for irrigation or in pest control – Contamination during storage or during the packing process – Insect or bird droppings contamination prior to picking 8 Cyclospora A coccidian, spore-forming protozoan Oocysts are 8-10 ㎛ in diameter Infection is through ingestion of sporulated oocysts in either food or water Oocysts require weeks to months (1-2 weeks in optimal conditions) outside humans to sporulate and become infectious (human-human transmission is unlikely) Infectious dose of oocysts is unknown. 9 Cyclospora Asymptomatic carriers may excrete oocysts without being ill – Natives of endemic areas may frequently be asymptomatic, but infectious – Cyclospora in endemic in Haiti, Peru and Nepal where rainy-season outbreaks occur. – Outside these areas, infections are usually travel related. 10 Cyclospora Lifecycle 11 Cyclospora Health Effects Clinical features include: – Watery diarrhea, usually yellow or khaki green in color, without blood or inflammatory cells, is the chief symptom, lasting an average of 19-43 days – Diarrhea may be explosive – Severe fatigue, anorexia, nausea, vomiting, abdominal bloating, weight loss and stomach cramps – A small percentage may experience fever, chills and a flu-like illness 12 Cyclospora Health Effects Symptoms may occur anywhere from 1 to 11days after exposure with an average of a week. Untreated cases in immuno-competent hosts may last 1-2 months or longer Reactive arthritis is seen following longer lasting infections. May also see ocular inflammation or sterile urethritis 13 Cyclospora Health Effects Low levels are sufficient to cause disease Organism is resistant to chlorine – In endemic areas, boiling water or the use of filtration is suggested. 14 Cyclospora Diagnosis Diagnosis may be through: – Detection of eggs in stool samples or duodenal aspirates Oocysts autofluoresce a bright blue under UV light (365nm) Acid-fast staining may be used to show oocysts – Detection of parasite DNA through PCR 15 Autofluorescence under UV light (365 nm) 16 Cyclospora Diagnosis 17