Rotavirus Antigenemia in Children Is Associated with Viremia

BACKGROUND: Antigenemia is commonly detected in rotavirus-infected children. Although rotavirus RNA has been detected in serum, definitive proof of rotavirus viremia has not been shown. We aimed to analyze a defined patient population to determine if infectious virus could be detected in sera from children with rotavirus antigenemia. METHODS AND FINDINGS: Serum samples obtained upon hospitalization from children with gastroenteritis (57 stool rotavirus-positive and 41 rotavirus-negative), children with diagnosed bronchiolitis of known (n = 58) or unknown (n = 17) viral etiology, children with noninfectious, nonchronic conditions (n = 17), and healthy adults (n = 28) were tested for rotavirus antigen by enzyme immunoassay (EIA). Results of serum antigen testing were assessed for association with clinical and immunological attributes of the children. Rotavirus antigenemia was detected in 90% (51/57) of children with rotavirus-positive stools, in 89% (8/9) of children without diarrhea but with rotavirus-positive stools, in 12% (2/17) of children with bronchiolitis of unknown etiology without gastroenteritis, and in 12% (5/41) of children with gastroenteritis but with rotavirus-negative stools. Antigenemia was not detected in sera from children with noninfectious nonchronic conditions, children with bronchiolitis of known etiology and no gastroenteritis, or healthy adults. Neither age nor timing of serum collection within eight days after onset of gastroenteritis significantly affected levels of antigenemia, and there was no correlation between antigenemia and viral genotype. However, there was a negative correlation between serum rotavirus antigen and acute rotavirus-specific serum IgA (r = −0.44, p = 0.025) and IgG (r = −0.40, p = 0.01) titers. We examined 11 antigen-positive and nine antigen-negative sera for infectious virus after three blind serial passages in HT-29 cells using immunofluorescence staining for rotavirus structural and nonstructural proteins. Infectious virus was detected in 11/11 (100%) sera from serum antigen-positive children and in two out of nine (22%) sera samples from antigen-negative children (p = 0.002). CONCLUSIONS: Most children infected with rotavirus are viremic. The presence of viremia is directly related to the detection of antigenemia and is independent of the presence of diarrhea. Antigenemia load is inversely related to the titer of antirotavirus antibody in the serum. The finding of infectious rotavirus in the blood suggests extraintestinal involvement in rotavirus pathogenesis; however, the impact of rotavirus viremia on clinical manifestations of infection is unknown

Low Prevalence of Chlamydia trachomatis Infection in Non-Urban Pregnant Women in Vellore, S. India

Objective: To determine the prevalence and risk factors for Chlamydia trachomatis (CT) infection in pregnant women and the rate of transmission of CT to infants. Methods: Pregnant women ($28 weeks gestation) in Vellore, South India were approached for enrollment from April 2009 to January 2010. After informed consent was obtained, women completed a socio-demographic, prenatal, and sexual history questionnaire. Endocervical samples collected at delivery were examined for CT by a rapid enzyme test and nucleic acid amplification test (NAAT). Neonatal nasopharyngeal and conjunctival swabs were collected for NAAT testing. Results: Overall, 1198 women were enrolled and 799 (67%) endocervical samples were collected at birth. Analyses were completed on 784 participants with available rapid and NAAT results. The mean age of women was 25.8 years (range 18– 39 yrs) and 22 % (95 % CI: 19.7–24.4%) were primigravida. All women enrolled were married; one reported.one sexual partner; and six reported prior STI. We found 71 positive rapid CT tests and 1/784 (0.1%; 95 % CI: 0–0.38%) true positive CT infection using NAAT. Conclusions: To our knowledge, this is the largest study on CT prevalence amongst healthy pregnant mothers in southern India, and it documents a very low prevalence with NAAT. Many false positive results were noted using the rapid test. Thes

Evaluation of Target Attainment of Vancomycin Area Under the Curve in Children With Methicillin-Resistant Staphylococcus Aureus Bacteremia.

BACKGROUND: Vancomycin is often required to treat methicillin resistant Staphylococcus aureus (MRSA) bacteremia in children. Treatment failure occurs in up to 50% of adults and is associated with a 24 hour area under the curve/minimum inhibitory concentration (AUC(24h)/MIC) <400. We sought to identify patient factors associated with vancomycin AUC and whether AUC(24h)/MIC <400 was predictive of treatment failure in children. METHODS: Hospitalized children <18 years of age with MRSA bacteremia receiving vancomycin were included in a retrospective cohort study. AUC(24h) was calculated using a validated PK model. Factors such as age, gender, underlying conditions, presence of foreign bodies, patient site of infection, and markers of illness severity were examined for an association with vancomycin AUC, and AUC(24h)/MIC was evaluated for an association with treatment failure. RESULTS: Subjects requiring intensive care (ICU) support were significantly more likely to have higher vancomycin AUC(24h) and AUC(avg) than those subjects not needing ICU support. While vancomycin serum trough concentrations are predictive of vancomycin AUC, sub-optimal exposure of vancomycin occurred in almost 20% of subjects despite trough concentrations within the target range. A relationship between vancomycin AUC(24h)/MIC and treatment failure could not be established. CONCLUSIONS: To ensure optimal AUC/MIC pharmacodynamic index, especially in critically ill patients, estimation of the AUC is critical

CT Prevalence Studies in India.

<p>This table shows a review on Indian data which show a wide variation in CT prevalence and methods of laboratory confirmation.</p