Vaccination and unexplained sudden death risk in Taiwanese infants.

PURPOSE: In March 1992, eight infants who had died within 36 hours of receiving whole-cell pertussis vaccine (diphtheria, tetanus, and whole-cell pertussis [DTwP]) prompted the Taiwan health authorities to suspend its use. We conducted an investigation of vaccination and sudden unexplained infant death (SUID) and repeated it more recently after Taiwan switched to acellular pertussis vaccine (diphtheria, tetanus, and acellular pertussis [DTaP]) in 2010. METHODS: All SUIDs aged 31-364 days during 1990-1992 and 1996-2013 were selected from the death registration databases. The case-control investigation matched each case to two controls on clinic, sex, and birth date, whereas the follow-up self-controlled case series study compared risk of death during the 30-day post-vaccination risk periods with those in the control periods within the same case. RESULTS: Sudden unexplained infant death was associated with never receiving DTwP (odds ratio 2.28, 95% confidence interval 1.25-4.15) in the case-control investigation. The odds ratios within 0-1, 2-7, 8-14, and 15-30 days of DTwP administration were 1.18, 0.26, 0.50, and 0.77. In the 1996-2013 self-controlled case series studies, this temporal shift between DTwP and SUID was consistently observed for female (incidence rate ratio 1.70, 0.75, 1.01, and 0.84) but not male or DTaP recipients. A pooled analysis showed significant risk within 2 days of receiving DTwP in female infants (incidence rate ratio 1.66, 95% confidence interval 1.05-2.60). CONCLUSIONS: Being unvaccinated and recent receipt of DTwP in female infants was significantly associated with SUID; the latter was consistent with a temporal shift pattern without overall increase in risk. The currently used pertussis vaccine, DTaP, did not increase risk of SUID. Copyright © 2016 John Wiley & Sons, Ltd.

Prevalence of undiagnosed HIV infection among persons aged ≥13 years--National HIV Surveillance System, United States, 2005-2008.

In the United States, approximately 1.1 million adults and adolescents are living with human immunodeficiency virus (HIV) infection and, each year, another 50,000 become infected. At the end of 2008, approximately 20% of the persons living with HIV had an undiagnosed infection. Of those living with HIV at the end of 2008, nearly two thirds were racial/ethnic minorities and half were men who have sex with men (MSM). In 2007, HIV ranked fifth as a leading cause of death among persons aged 35-44 years in the United States but third among blacks or African Americans in this age group. In 40 states with longstanding confidential name-based HIV surveillance systems, 33% of the estimated 41,768 adults and adolescents diagnosed with HIV infection in 2008 developed acquired immunodeficiency syndrome (AIDS) within 1 year and, of these, 44% received their initial diagnosis in an acute care setting, suggesting that they received HIV testing late in the course of the infection. HIV-infected persons who are unaware of their infection or who receive a late diagnosis cannot benefit fully from timely initiation of therapy and are more likely to experience HIV-related morbidity and premature mortality. In addition, persons unaware of their infection are more likely to transmit HIV to others because of a higher prevalence of high-risk sexual behaviors and higher levels of viral RNA that continue to replicate without appropriate antiretroviral treatment.

Undiagnosed HIV prevalence among adults and adolescents in the United States at the end of 2006.

OBJECTIVES: To describe adults/adolescents (age 13 years and older) living with undiagnosed HIV infection in the United States at the end of 2006. METHODS: HIV prevalence and percentage undiagnosed were estimated from cumulative HIV incidence using an extended back-calculation model (using both HIV and AIDS data, the time of first diagnosis with HIV, and disease severity at diagnosis) and estimated cumulative deaths. RESULTS: An estimated 1,106,400 adults/adolescents (95% confidence interval = 1,056,400-1,156,400) were living with HIV in the United States at the end of 2006; overall, 21.0% (232,700; 95% confidence interval = 221,200-244,200) were undiagnosed. Whites had the lowest percentage undiagnosed (18.8%) compared with Hispanics/Latinos (21.6%), blacks/African Americans (22.2%), American Indians/Alaska Natives (25.8%), and Asians/Pacific Islanders (29.5%; all P < 0.001). Persons with a behavioral risk of injection drug use (IDU) had the lowest percentage undiagnosed (female IDU: 13.7% and male IDU: 14.5%); men exposed through heterosexual contact had the highest (26.7%) followed by men who have sex with men (23.5%). CONCLUSIONS: Differences in undiagnosed HIV were evident across demographic and behavior groups. Effective testing programs and early access to treatment and prevention services are necessary to reduce undiagnosed HIV infections and HIV prevalence.

Safety of thimerosal-containing vaccines: a two-phased study of computerized health maintenance organization databases.

OBJECTIVE: To assess the possible toxicity of thimerosal-containing vaccines (TCVs) among infants. METHODS: A 2-phased retrospective cohort study was conducted using computerized health maintenance organization (HMO) databases. Phase I screened for associations between neurodevelopmental disorders and thimerosal exposure among 124 170 infants who were born during 1992 to 1999 at 2 HMOs (A and B). In phase II, the most common disorders associated with exposure in phase I were reevaluated among 16 717 children who were born during 1991 to 1997 in another HMO (C). Relative risks for neurodevelopmental disorders were calculated per increase of 12.5 micro g of estimated cumulative mercury exposure from TCVs in the first, third, and seventh months of life. RESULTS: In phase I at HMO A, cumulative exposure at 3 months resulted in a significant positive association with tics (relative risk [RR]: 1.89; 95% confidence interval [CI]: 1.05-3.38). At HMO B, increased risks of language delay were found for cumulative exposure at 3 months (RR: 1.13; 95% CI: 1.01-1.27) and 7 months (RR: 1.07; 95% CI: 1.01-1.13). In phase II at HMO C, no significant associations were found. In no analyses were significant increased risks found for autism or attention-deficit disorder. CONCLUSIONS: No consistent significant associations were found between TCVs and neurodevelopmental outcomes. Conflicting results were found at different HMOs for certain outcomes. For resolving the conflicting findings, studies with uniform neurodevelopmental assessments of children with a range of cumulative thimerosal exposures are needed.

Adverse event reporting rates following tetanus-diphtheria and tetanus toxoid vaccinations: data from the Vaccine Adverse Event Reporting System (VAERS), 1991-1997.

Since 1966, the Advisory Committee on Immunization Practices (ACIP) has recommended tetanus-diphtheria toxoid (Td) be used instead of single antigen tetanus toxoid (TT) because, while both vaccines protect against tetanus, only Td protects against diphtheria. Despite this recommendation, approximately 2.5 million doses of TT were distributed annually from 1991 to 1997. One possible explanation for the continued use of TT is concern about the relative safety of Td. Small clinical trials found Td to be associated with a higher rate of local vaccine-associated adverse events (VAEs) than TT. To determine if the findings from the trials would hold up on a larger scale, we compared the rate of reporting to the Vaccine Adverse Event Reporting System (VAERS), a passive reporting system, after either vaccine from 1991 to 1997. There were 40 reports per million doses of Td, and 27 reports per million doses of TT, for a reporting rate ratio of 1.4. Reporting rates to VAERS are lower than the rates of VAEs identified in the clinical trials, but the magnitude of the difference in VAEs following TT versus Td is similar. While reporting rates are lower after TT than Td, rates of reported VAEs after both vaccines are low.