Epidemiology of Salmonellosis Among Infants in the United States: 1968-2015.

OBJECTIVES: Describe characteristics of gastroenteritis, bacteremia, and meningitis caused by nontyphoidal Salmonella among US infants. METHODS: We analyze national surveillance data during 1968-2015 and active, sentinel surveillance data during 1996-2015 for culture-confirmed Salmonella infections by syndrome, year, serotype, age, and race. RESULTS: During 1968-2015, 190 627 culture-confirmed Salmonella infections among infants were reported, including 165 236 (86.7%) cases of gastroenteritis, 6767 (3.5%) bacteremia, 371 (0.2%) meningitis, and 18 253 (9.7%) with other or unknown specimen sources. Incidence increased during the late 1970s-1980s, declined during the 1990s-early 2000s, and has gradually increased since the mid-2000s. Infants' median age was 4 months for gastroenteritis and bacteremia and 2 months for meningitis. The most frequently reported serotypes were Typhimurium (35 468; 22%) for gastroenteritis and Heidelberg for bacteremia (1954; 29%) and meningitis (65; 18%). During 1996-2015 in sentinel site surveillance, median annual incidence of gastroenteritis was 120, bacteremia 6.2, and meningitis 0.25 per 100 000 infants. Boys had a higher incidence of each syndrome than girls in both surveillance systems, but most differences were not statistically significant. Overall, hospitalization and fatality rates were 26% and 0.1% for gastroenteritis, 70% and 1.6% for bacteremia, and 96% and 4% for meningitis. During 2004-2015, invasive salmonellosis incidence was higher for Black (incident rate ratio, 2.7; 95% confidence interval, 2.6-2.8) and Asian (incident rate ratio, 1.8; 95% confidence interval, 1.7-1.8) than white infants. CONCLUSIONS: Salmonellosis causes substantial infant morbidity and mortality; serotype heidelberg caused the most invasive infections. Infants with meningitis were younger than those with bacteremia or gastroenteritis. Research into risk factors for infection and invasive illness could inform prevention efforts.

Salmonella enterica Serotype Newport Infections in the United States, 2004-2013: Increased Incidence Investigated Through Four Surveillance Systems.

Newport is the third most common Salmonella enterica serotype identified among the estimated 1.2 million human salmonellosis infections occurring annually in the United States. Risk factors for infection and food items implicated in outbreaks vary by antimicrobial resistance pattern. We conducted a descriptive analysis of data from four enteric disease surveillance systems capturing information on incidence, demographics, seasonality, geographic distribution, outbreaks, and antimicrobial resistance of Newport infections over a 10-year period from 2004 through 2013. Incidence increased through 2010, then declined to rates similar to those in the early years of the study. Incidence was highest in the South and among children <5 years old. Among isolates submitted for antimicrobial susceptibility testing, 88% were susceptible to all antimicrobials tested (pansusceptible) and 8% were resistant to at least seven agents, including ceftriaxone. Rates of pansusceptible isolates were also highest in the South and among young children, particularly in 2010. Pansusceptible strains of Newport have been associated with produce items and environmental sources, such as creek water and sediment. However, the role of environmental transmission of Newport in human illness is unclear. Efforts to reduce produce contamination through targeted legislation, as well as collaborative efforts to identify sources of contamination in agricultural regions, are underway.

Naturalistic assessment of demand for cigarettes, snus, and nicotine gum.

RATIONALE: Behavioral economic measures of demand provide estimates of tobacco product abuse liability and may predict effects of policy-related price regulation on consumption of existing and emerging tobacco products. OBJECTIVE: In the present study, we examined demand for snus, a smokeless tobacco product, in comparison to both cigarettes and medicinal nicotine. We used both a naturalistic method in which participants purchased these products for use outside the laboratory, as well as laboratory-based self-administration procedures. METHODS: Cigarette smokers (N = 42) used an experimental income to purchase their usual brand of cigarettes and either snus or gum (only one product available per session) across a range of prices, while receiving all products they purchased from one randomly selected price. In a separate portion of the study, participants self-administered these products during laboratory-based, progressive ratio sessions. RESULT: Demand elasticity (sensitivity of purchasing to price) was significantly greater for snus than cigarettes. Elasticity for gum was intermediate between snus and cigarettes but was not significantly different than either. Demand intensity (purchasing unconstrained by price) was significantly lower for gum compared to cigarettes, with no significant difference observed between snus and cigarettes. Results of the laboratory-based, progressive ratio sessions were generally discordant with measures of demand elasticity, with significantly higher "breakpoints" for cigarettes compared to gum and no significant differences between other study products. Moreover, breakpoints and product purchasing were generally uncorrelated across tasks. CONCLUSIONS: Under naturalistic conditions, snus appears more sensitive to price manipulation than either cigarettes or nicotine gum in existing smokers.

The Role of HIV in the Household Introduction and Transmission of Influenza in an Urban Slum, Nairobi, Kenya, 2008-2011.

BACKGROUND: Little is known about how human immunodeficiency virus (HIV) infection affects influenza transmission within homes in sub-Saharan Africa. METHODS: We used respiratory illness surveillance and HIV testing data gathered in Kibera, an urban slum in Nairobi, Kenya, to examine the impact of HIV status on (1) introducing influenza to the home and (2) transmitting influenza to household contacts. RESULTS: While HIV status did not affect the likelihood of being an influenza index case, household contacts of HIV-infected influenza index cases had twice the risk of developing secondary influenza-like illness than contacts of HIV-negative index cases. CONCLUSIONS: HIV-infected influenza index cases may facilitate transmission of influenza within the home.