The Prevalence of Parasitic Contamination of Fresh Vegetables in Tehran, Iran

Objective: Parasitic diseases have created numerous health and economic problems in developing and developed countries. One of the most prevalent ways of transmitting diseases is by consuming raw vegetables that are contaminated with parasites. With respect to the importance of healthy vegetable consumption, an awareness of vegetable status helps prevent infection. Therefore, the present study was conducted to determine the level of parasitic contamination of vegetables consumed in Tehran. Methods: This descriptive and cross-sectional study was conducted on vegetable samples spread in Tehran from October 2017 to September 2018. The samples included 240 vegetables selected from 10 types of vegetable including leek, basil, mint, spring onion, radish, parsley, lettuce, cress, tarragon and coriander. Each sample was examined after passing through washing and centrifuging. Parasitic agents such as unicellular, egg and larva of the worms were studied. The data were analysed using SPSS software. Conclusion: Parasitic infection was observed in 62 samples (25.8%). The highest and lowest rates of contamination were observed in coriander and lettuce, respectively. Rhabditoid larva (12.5%; 15 cases) and Physaloptera egg (1.6%; 2 cases) were the most and least observed parasites, respectively. Other parasites such as Entamoeba, Giardia, Blastocystis, Hymenolepis, Ascaris and the egg and larva of hookworms were also observed. Despite the relative improvement of social, agricultural, economic and health conditions in Tehran, the prevalence of parasitic infections still persists. Factors such as developing modern waste collection methods, improving urban sewage systems, preventing domestic animal traffic on pastures and promoting the knowledge of different classes of people could reduce the prevalence of these types of diseases.

Prevalence and molecular characterization of Cryptosporidium spp. and Giardia intestinalis in household dogs and cats from Shiraz, Southwestern Iran.

In the present study, a total of 615 fecal samples from veterinary clinics were screened by microscopy for the presence of Cryptosporidium and Giardia oocysts. Molecular genotyping of Cryptosporidium and Giardia were carried out using PCR and sequence analysis. Overall, Cryptosporidium and Giardia oocysts were detected in the 0.6% (2/315) and 1.9% (6/315) of dogs and in the 0.7% (2/300) and 1.3% (4/300) of cats, respectively. Sequencing revealed the presence of C. canis (n = 2) in dogs and C. felis (n = 2) in cats. Moreover, G. intestinalisassemblage D (n = 2), C (n = 3) and A, sub-assemblage AII (n = 1) were identified in dogs; G. intestinalis assemblage F (n = 3) and assemblage A, sub-assemblage AI (n = 1) were identified in cats. The highest prevalence of Giardia was observed in dogs younger than one year (6/315), and in those with diarrhea (p < 0.05). Data of the study suggest that dogs and cats play a minor role in the zoonotic transmission of cryptosporidiosis and giardiasis in Southwestern Iran.

Comparison of three cost effective staining methods for detection of Pneumocystis jirovecii.

Pneumocystis pneumonia due to Pneumocystis jirovecii infection is an emerging health problem not only for HIV-infected patients but also for other immunocompromised patients in many countries. We compared Gomori methenamine silver (GMS), Toluidine Blue O (TBO) and Giemsa staining methods using standard procedures. The sensitivity and specificity of GMS were 100 %. The sensitivity and specificity of TBO were 96 and 100 %, respectively. The sensitivity and specificity of Giemsa stain were 84 and 90 %, respectively. Only GMS had positive and negative predictive values of 100 % while PPV and NPV for TBO were 100 and 90.9 %, and for Giemsa stain were 95.4 and 69.2 %, respectively. Therefore, our results suggest that if TBO or Geimsa stains are used as the primary staining methods in a clinical laboratory, then confirmation with a GMS staining method should be performed to increase the sensitivity and specificity of the final test result.