NEW MICROBIOLOGICA, 34, 17-24, 2011 A waterborne outbreak of epidemic diarrhea due to group A rotavirus in Malatya, Turkey Mehmet Koroglu 1 , Yusuf Yakupogullari 1,2 , Barıs Otlu 2 , Serhat Ozturk 3 , Mehmet Ozden 4 , Ali Ozer 5 , Kemal Sener 6 , Rıza Durmaz 7 1 Clinic Microbiology Resident, Malatya State Hospital, Clinic Microbiology Department, Malatya-Turkey; 2 Assistant Professor, Inonu University, Faculty of Medicine, Department of Clinical Microbiology, Molecular Microbiology Section, Malatya-Turkey; 3 Public Health Resident, Malatya State Hospital, Public Health Department, Malatya-Turkey; 4 Associated Professor, Firat University Medical Center, Immunology and Infectious Diseases Departments, Elazig-Turkey; 5 Public Health Resident, Malatya Beydagi State Hospital, Public Health Department, Malatya-Turkey; 6 Turkish Ministry of Health, Co-Director of Malatya City Health Menagerie; 7 Professor, Inonu University, Faculty of Medicine, Department of Clinical Microbiology, Molecular Microbiology Section, Malatya-Turkey INTRODUCTION Rotavirus is a non-enveloped, triple-layered icosa- hedral virus that is classified as a genus in the Reoviridae family. The virus has a double-strand- ed RNA genome made up of 11 segments that en- code six viral proteins (VP) and six non-structur- al proteins (NSP). The virus possesses at least three important antigenic specificities based on VP6, VP7 (glycoprotein designated G) and VP4 Corresponding author Yusuf Yakupogullari Inou University, Faculty of Medicine Department of Clinic Microbiology 44000 Malatya, Turkey E-mail: yusufyakoup@yahoo.com (protease-sensitive protein P) (Fischer et al., 2004). Seven different rotavirus groups (named A to G) have been characterized in many animal species. Group A rotavirus is the primary human pathogen world-wide, and is the most common cause of rotavirus epidemics and sporadic cases (Parashar et al., 2005). On the other hand, group B and C rotaviruses, also known as swine ro- taviruses (Parashar et al., 2005), have been re- ported in limited geographic regions (Cunliffe et al., 2005; Bern et al., 1992; Fischer et al., 2005). Rotavirus is one of the most frequently reported etiologic agents of severe and dehydrating gas- troenteritis. Approximately one-third of all diar- rheal pediatric hospital admissions can be at- tributed to this pathogen, and an estimated We characterized an outbreak of acute diarrheal disease caused by group A rotavirus that occurred during the Autumn of 2005 in Malatya City, Turkey. A total 9907 patients between 0 to 91 years old (mean age: 25.05±19.67) were includ- ed in the epidemic. The patients’ data were prospectively collected and statistically analyzed. Microbiologic analyses were performed to determine the etiologic agent. Rapid onset diarrhea (98.36%), abdominal cramps (69%), fever (44.4%) and vomiting (69.6%) were the most common symptoms observed in patients. Rotavirus antigen was detect- ed in 52.7% of the studied patients. RT-PCR analysis led to identification of Group A rotavirus as the causative agent of this epidemic. Simultaneous measurements of the drinking water samples yielded very low chlorine levels; as low as 0 to 0.05 mg/L. The outbreak investigation team indicated possible contamination of a large water depository from a water well, which supplies drinking water to two major districts of the city. Effective chlorination and blockage of the passage between the well and the water depository stopped the outbreak. This outbreak shows the high epidem- ic potency of rotavirus in large human populations, including all age groups, and underlines the importance of water safety in pipeline systems. KEY WORDS: Rotavirus, Outbreak, Waterborne, Diarrhea, Chlorination SUMMARY Received September 01, 2009 Accepted July 06, 2010