Staphylococcal poisoning during a village festival, Medina, Misamis Oriental, Philippines in 2014.

INTRODUCTION

On 18 August 2014, cases of food poisoning in San Vicente Village were reported to the Event-Based Surveillance & Response Unit of the Philippine Department of Health. An investigation was conducted to identify the implicated source, describe the outbreak and evaluate the risk factors.

METHODS

A case-control study was conducted. A suspected case was a previously well individual of Medina who attended the village festival and developed abdominal pain and vomiting with or without nausea, diarrhoea and fever from 18 to 19 August. A confirmed case was a suspected case with a rectal swab positive for bacterial culture. Rectal swabs, water and food samples were sent to the national reference laboratories. Food source and consumption interviews and environmental inspections were conducted.

RESULTS

Sixty-four cases and 123 unmatched controls were identified. The median incubation period was 1 hour 15 minutes. Five cases (8%) were positive for Staphylococcus aureus, one (2%) for Aeromonas hydrophilia and one (2%) for Shigella boydii. One (14%) water sample was positive for Aeromonas spp. Of the collected food samples, beef steak was positive for Staphylococcus aureus. Risk factors were consumption of Filipino-style beef stew (odds ratio [OR]: 6.62; 95% confidence interval [CI]: 2.90-15.12) and stir-fried noodles (OR: 3.15; 95% CI: 1.52-6.50). Prolonged serving time and improper food storage were noted.

DISCUSSION: In this foodborne outbreak, Staphylococcus aureus was the likely causative agent. Meals were contaminated due to improper food handling practices. We recommend that a policy be created to mandate that village-appointed food handlers undergo food safety training.