| Nontyphoidal Salmonellae, particularly serotypes Typhimurium, Enteritidis, Heidelberg, and Newport, are common causes of foodborne gastroenteritis in the United States (US). It is estimated that about 1.4 million people suffer from salmonellosis each year with an estimated annual cost of {dollar}0.5 to {dollar}2.3 billion. Infections with these serotypes are often associated with the consumption of undercooked chicken, eggs, pork and beef, and contaminated vegetables.; Consumption of foods varies among the different ethnic groups. Additionally, several demographic factors may influence food intake behavior. The objectives of this study were to identify the high-risk population by the determination of the incidence of human infections with the most common Salmonella serotypes in Michigan in terms of time, place of residence (urban vs. rural counties) and demographic (age, gender, race and ethnicity), and whether the incidence is associated with low socioeconomic status (SES). This study was conducted by analyzing the 1995 to 2001 surveillance data on salmonellosis reported to Michigan Department of Community Health. Data on salmonellosis were analyzed by host related factors (race, age, place of residence) and linked to Salmonella serotypes to reveal the trends and important risk factors for the infections. This study revealed that from 1998 to 2001, the incidence of Typhimurium and Enteritidis significantly decreased where as the incidence of Newport significantly increased. Infants aged <1 year had the highest incidence followed by children aged 1 to 4 years. Among cases whose race or ethnicity was known, African-Americans had a significantly higher incidence of Typhimurium, Enteritidis, Heidelberg, and Newport compared with Whites; Hispanics had a significantly higher incidence of Enteritidis compared with Non-Hispanics. The high incidence among African-Americans and Hispanics is largely driven by the high incidence among their infants; children aged 1-4 years and elderly in urban counties. Among African-American infants, the incidence of Typhimurium and Enteritidis peaked at 2 to 4, and 9 and 10 months of age. African-American infants have a significantly higher incidence of invasive salmonellosis compared with White infants. Among African-Americans, the incidence of Typhimurium and Enteritidis increased during the winter months (October-December) where as among whites the incidence decreased. People living in poor area indicated by the census tracts had a significantly higher incidence of Enteritidis compared with people living in economically better areas. Because about 40% and 70% of the cases did not have information on race and ethnicity respectively, the findings regarding the racial and ethnicity differences in the infections should be interpreted with caution. Nevertheless, this information can be used by the state and local health departments of Michigan as a basis to guide salmonellosis prevention efforts in specific population subgroups and to conduct further studies to determine the risk factors for the high incidence among African-American and Hispanic infants, children and elderly; and among people living in poor census tracts. |
