Salmonellosis-Related Mortality in the United States, 1990–2006

Abstract

Despite the recognition of nontyphoidal Salmonella as an important foodborne infection, few data exist on salmonellosis as a cause of death in the United States. To provide a quantitative assessment of the burden of Salmonella-related mortality in the United States, we examined national multiple-cause-of-death data for the years 1990-2006. Crude and age-standardized rates of salmonellosis mortality and 95% confidence intervals (CI) were computed for race, sex, age, state of residence, and year. A matched case-control analysis, using non-Salmonella deaths as controls, was conducted to determine whether certain diseases were more likely to be listed as comorbid conditions for Salmonella-related death. Salmonellosis was reported as an underlying or associated cause of death among 1316 persons, with an average annual age-adjusted mortality rate of 0.03 per 100,000 person-years. Salmonellosis mortality rates were higher among blacks and Asian/Pacific Islanders with an age-adjusted rate ratio of 2.61 (95% CI, 2.43-2.81) and 2.48 (95% CI, 2.30-2.67), respectively. Rates were also higher in males with an age-adjusted rate ratio of 1.84 (95% CI, 1.68-2.03). The highest frequency of deaths occurred among adults age 75-84 (n = 329; 25% of all cases). A declining trend in salmonellosis-related deaths was observed over the study period. Several comorbid conditions were associated with Salmonella deaths, including HIV and connective tissue disorders, with matched odds ratios of 7.44 (95% CI, 5.04-10.97) and 3.69 (95% CI, 1.88-7.25), respectively. Despite declining trends, salmonellosis continues to be an important cause of preventable death especially among selected subgroups, underscoring the need for expanded prevention efforts.

Clinical Features of Human Salmonellosis Caused by Bovine-Associated Subtypes in New York

“…Such low mortality is a reflection of current standards of care, and it coincides with the decreasing salmonellosis case fatality reported in other studies over time (MacCready et al, 1957;Saphra and Winter, 1957;Jones et al, 2008;Cummings et al, 2010;Ruzante et al, 2011).…”

The Burden of Salmonellosis in the United States

“…Between 1990 and 2006 the age-adjusted mortality rate for human salmonellosis declined from 0.06 per 100,000 population (95%CI, 0.05-0.07; n=136 deaths) to 0.01 per 100,000 population (95%CI, 0.01-0.02; n=45 deaths). The variance between deaths and incidence, in terms of trends over the past decade show that deaths have decreased (Cummings PL et al, 2010), but incidence has increased (CDC, 2011). This difference could potentially be the result of better medical treatment or other contributing factors accounting for the decline in deaths.…”

“…While whites had the highest absolute number of deaths (n = 893), they had the lowest age-adjusted mortality rate (0.023 per 100,000 population; 95% CI, 0.021-0.024). Reasons for disparities in Salmonella mortality based on gender and race/ethnicity have been discussed in a previously published paper (Cummings PL et al, 2010). California and New York had the highest number of deaths (n=219 and n=105, respectively), but relatively low age-adjusted mortality rates (0.04 per 100,000 population, 95% CI, 0.04-0.05 and 0.03 per 100,000 population, 95% CI, 0.02-0.04, respectively).…”

“…Although Hawaii and District of Columbia had smaller numbers, they had the highest age-adjusted www.intechopen.com mortality rates during 1990-2007 (0.08 per 100,000 population, 95% CI, 0.04-0.12; n=18 and 0.08 per 100,000 population, 95% CI, 0.02-0.13; n=8, respectively). Methods used in this updated analysis are similar to those previously described in Cummings PL et al, 2010. Briefly, years of potential life lost (YPLL) were calculated by subtracting the age in years at the time of death from 75 years (Gardner, 1990).…”

“…Comorbid health conditions and their related immuno-suppressive treatments may be particularly problematic, especially among vulnerable groups at high risk of progressing to severe forms of salmonellosis (Trevejo et al, 2003;Cummings PL et al, 2010). For example, those with HIV/AIDS, certain types of cancers (e.g., leukemia, bone marrow), or autoimmune disorders are at significantly greater risk for death, as compared to persons without these conditions.…”