Antimicrobial investigation on the multi-state outbreak of salmonellosis and shigellosis in Iran

Foodborne diseases are caused by indigestion of contaminated food. In some cases they may result in either hospitalization or death. The Centers for Disease Control (CDC) and Prevention in 2017 stated that 10% reduction in foodborne illness would prevent nearly five million illnesses every year. Approximately one out of six Americans become ill from contaminated foods or beverages every year. Another problem is drug resistance which is responsible for approximately 2 million illnesses and around 23000 dead every year. Nearly 400,000 Americans acquire antibiotic-resistant Salmonella or Campylobacter each year. The aim of this study was to evaluate the outbreak of salmonellosis and shigellosis along with their antibiotic susceptibility patterns in different provinces of Iran.

Over a period of 2 years from 2015 to 2016, a total of 1055 cases in 249 outbreaks reported in 20 provinces of Iran, as a part of surveillance by the National Institute of Health (NIH). The stool samples of patients were taken and tested for Salmonella spp. and Shigella spp. by conventional standard techniques. Disk diffusion was used for the antibiotic sensitivity test.

Of 1055 cases, 118 (11.2%) contained Shigella and 74 (7%) contained Salmonella. Antibiotic susceptibility tests showed that entirely 100% of Salmonella and Shigella isolates were susceptible to ciprofloxacin; whereas 12.2% of Salmonella and 98.2% of Shigella were resistant to cotrimoxazole.

Our results show that there is a need for more food handling practices to minimize the exposure of consumers to Salmonella and Shigella, at all points along the distribution chain.