Occurrence of Cryptosporidium sp. in fresh produce from the Metropolitan Area of Costa Rica: an update.

Abstract

Foodborne diseases represent a major global public health problem, causing significant morbidity and mortality, and substantial economic losses. Fruits and vegetables are considered among the main vehicles for transmission of infectious agents like bacteria, viruses, fungi and parasites, including Cryptosporidium sp. This protozoan parasite comprises many species that infect a wide range of hosts, is environmentally and geographically ubiquitous and has become one of the leading causes of diarrheal disease; in immunocompromised hosts, the infection can result in a chronic, life-threatening disease. Considering the importance of fruit and vegetable consumption in the daily diet and the need to ensure their safety, the aim of the study was to evaluate the presence of Cryptosporidium sp. in strawberries, lettuce and cilantro marketed in the Metropolitan Area of Costa Rica and to assess the degree of faecal contamination in these foods. For this purpose, 96 samples were analysed using parasitological and molecular methods that included a nested PCR to amplify Cryptosporidium sp. gp60 gene. Moreover, the presence of total and thermotolerant coliforms and Escherichia coli was also determined by culture methods and counts, for further identification using the VITEK system. Direct examination of wet mount and Ziehl-Neelsen stains revealed five Cryptosporidium sp. positive samples by microscopy and 22 positive samples by PCR; the identified species was Cryptosporidium parvum. Cilantro samples presented the highest counts of total, and thermotolerant coliforms and E. coli was identified in14 samples among 82 samples subjected to bacteriological analyses. The detection of C. parvum in raw vegetables and fruits from different provinces in Costa Rica, particularly using molecular techniques, demonstrates the need to strengthen surveillance and control in the production and marketing of these foods, to improve risk assessment and its relevance to public health.