Search

Infection with Toxoplasma gondii can lead to congenital and acquired disease, resulting in loss of vision and neurologic illness. We tested sera collected in the National Health and Examination Survey [...]

To the Editor: We correct the prevalence of Toxoplasma gondii immunoglobulin (Ig) G antibodies published in Emerging Infectious Diseases in 2003 (1). An incorrect cutoff value in the computer program [...]

Background. Toxocariasis results from infection with larval stages of a dog and cat intestinal nematode and causes human morbidity. The current United States estimate of Toxocara exposure is 13.9% (National Health and Nutrition Examination Survey [NHANES] III [1988-1994]). Methods. We used a multiplex bead-based assay (Tc-CTL-1MBA) with purified Toxocara canis antigen to estimate Toxocara antibody seroprevalence in serum of 13 509 persons aged =6 years from NHANES 2011-2014 and identified seropositivity risk factors. We tested a subset of 500 samples with the T. canis enzyme immunoassay used in NHANES III to estimate prior seroprevalence had samples from NHANES III been tested by Tc-CTL-1MBA. Results. The age-standardized estimate of Toxocara seroprevalence was 5.0% (95% confidence interval [CI], 4.2%-5.8%), lower than previously reported even after adjusting for increased Tc-CTL-1MBA specificity. Risk factors for seropositivity from multiple logistic regression were older age, non-Hispanic black/Hispanic origin, male sex, living below poverty level, households with =0.5 persons per room, less than college education, and birth outside of the United States. Conclusions. Toxocara seroprevalence estimates in 2011-2014 were lower than in a study from NHANES III (1988-1994), but seropositivity risk factors remained the same and should continue to be the focus of prevention efforts. [ABSTRACT FROM AUTHOR]

The article discusses the evidence of waning vaccine-induced immunity against coronavirus disease 2019 (COVID-19). Topics include the Centers for Disease Control and Prevention's (CDC) guidelines refer to 2 positive SARS-CoV-2 polymerase chain reaction (PCR) test results at least 90 days apart; naturally acquired immunity confers stronger protection against infection and symptomatic disease caused by the Delta variant of SARS-CoV-2, compared to the dose vaccine-induced immunity.

Objectives. We described seroprevalence of antibody to hepatitis A virus (anti- HAV) in the United States during 1999-2006 and compared it with seroprevalence before the availability of vaccine. Methods. We analyzed data from the 1988-1994 and 1999-2006 National Health and Nutrition Examination Survey (NHANES) to obtain estimates of anti- HAV seroprevalence for the U.S. household population. We grouped region of residence based on the 1999 Advisory Committee on Immunization Practices recommendations into 17 states with any recommendation (vaccinating) and 33 states without any recommendation (non-vaccinating). Results. During 1999-2006, the overall seroprevalence of anti-HAV was 34.9% (95% confidence interval [CI] 33.1, 36.7). During 1999-2006, U.S.-born children living in vaccinating states (33.8%, 95% CI 26.2, 42.2) had a higher seroprevalence than children in non-vaccinating states (11.0%, 95% CI 9.4, 12.8; p<0.001). Seroprevalence among children increased from 8.0% (95% CI 6.3, 10.1) during 1988-1994 to 20.2% (95% CI 16.0, 24.8) during 1999-2006 (p<0.001). For U.S.-born children aged 6-19 years, the strongest factor associated with seroprevalence was residence in vaccinating states. Among U.S.-born adults aged >19 years, the overall age-adjusted seroprevalence of. anti-HAV was 29.9% (95% CI 28.3, 31.5) during 1999-2006, which was not significantly different from the seroprevalence during 1988-1994 (32.2%, 95% CI 30.1, 34.4). Conclusions. Increases in seroprevalence among children in vaccinating states suggest a positive effect of the 1999 vaccination recommendations. [ABSTRACT FROM AUTHOR]

Objective. We estimated the varicella seroprevalence among the U.S. Population aged 6-49 years based on retested National Health and Nutrition Examination Survey (NHANES) specimens collected between 1999 and 2004—originally tested using a method unsuitable for detecting vaccine-induced immunity—and compared it with historical estimates. Methods. We performed a confirmatory test suitable for, detecting vaccine-induced immunity on all available specimens from 6- to 19-year-olds who originally tested negative (n=633), and on 297 randomly selected specimens that had tested positive. Retest results superseded original results for determining seroprevalence. We assessed seroprevalence for the entire sample aged 6-49 years (n=16,050) by participant demographic characteristics and compared it with historical estimates (NHANES 1988-1994). Results. The percentage of false-negative results for the original test was higher for specimens from younger children (6-11 years of age: 27.5%; 12-19 years of age: 13.3%) and for specimens collected most recently (2001-2004: 26.0%; 1999-2000: 12.6%). The age-adjusted rate of varicella seroprevalence for 1999-2004 was 93.6% for 6- to 19-year-olds and 98.0% for adults aged 20-49 years compared with 90.0% and 98.1%, respectively, for 1988-1994. We found an increase in seropositivity between the survey periods, from 93.2% to 97.2% (p<0.001) among 12- to 19-year-olds. For children, non-Hispanic black ethnicity and younger age were associated with lower seroprevalence in both survey periods. Conclusions. Varicella seroprevalence increased with age among children and was uniformly high in the U.S. adult population between 1999 and 2004. The original testing produced false-negative seroprevalence results among children's specimens collected between 1999 and 2004 from 6- to 19-year-olds. [ABSTRACT FROM AUTHOR]