The prevalence of Listeria spp. food contamination in Iran: A systematic review and meta-analysis.

Listeria monocytogenes can cause circling disease, encephalitis, meningitis, septicemia, and mastitis in dairy cattle. Contamination from the environment can contaminate foods with Listeria spp. Consumption of foods containing L. monocytogenes can lead to listeriosis in susceptible people (adults with a compromised immune system), pregnant women, and infants. The objective of this study was to determine the prevalence of Listeria spp. and L. monocytogenes in various foods in Iran. We searched PubMed, Science direct, Scopus, Google scholar, and Iranian local databases including Iranian scientific information database and Magiran for relevant studies up to May 2015 using related keywords. In our preliminary search, we retrieved 1344 articles. After removing duplicates and reviewing titles/abstracts, 117 articles were considered, out of which, 75 articles had sufficient quality for inclusion in this meta-analysis. The prevalence of Listeria spp. contamination was about 18.3% in poultry, 8.5% in raw meat, 14.6% in ready-to-eat (RTE) foods, 10% in sea foods, 7.3% in traditional dairy, 3.2% in commercial dairy, and 0.1% in eggs. The findings showed that L. monocytogenes was most prevalent in ready to eat (9.2%), seafood (5.1%), poultry (5%), traditional dairy (4%), raw meat (2.6%), commercial dairy (1.4%), and egg (0.2%), respectively. Furthermore, the presence of L. monocytogenes particularly in RTE foods (that are consumed without further heat processing) and under-cooked products could be a potential risk for public health. So, contamination should be controlled at all levels of the food chain.

The Nickel Concentration in Breast Milk during the First Month of Lactation in Yazd, Center of Iran.

Breastfeeding plays an important role in the growth and development of breastfed infants, especially in the first 6 months of their lives. The present study was conducted to determine the nickel concentrations in breast milk of lactating women in Yazd, Iran. One hundred fifty volunteers were selected among nursing mothers referring to health centers in Yazd. In the first month of lactation, milk samples were collected three times, on days 3 to 5 (first), 16 (Second), and 30 (third) after delivery. Nickel concentration of the samples was measured by atomic absorption spectrophotometer. Demographic variables were collected through a questionnaire which was completed by mothers. The mean age of the study group was 27.40 ± 4.66 years. The mean nickel concentrations in breast milk at the first, second, and third samples were 47.3 ± 7.40, 49.9 ± 8.05, and 54.8 ± 7.38 µg/l, respectively. The concentration of nickel in the breast milk of more than 86 % of mothers was higher than the permissible range for it. There was no significant relationship between the mean value of nickel in breast milk and education, age, and job of mothers. High level of nickel in breast milk may be attributed to consumed food and drinking water containing nickel. Monitoring the nickel level in breast milk regularly is recommended.