Background. Study of meningococcal carriage is essential to understanding the epidemiology of Neisseria meningitidis infection.Methods. Twenty cross-sectional carriage surveys were conducted in 7 countries in the African meningitis belt; 5 surveys were conducted after introduction of a new serogroup A meningococcal conjugate vaccine (MenAfriVac). Pharyngeal swab specimens were collected, and Neisseria species were identified by microbiological and molecular techniques.Results. A total of 1687 of 48 490 participants (3.4%; 95% confidence interval [CI], 3.2%–3.6%) carried meningococci. Carriage was more frequent in individuals aged 5–14 years, relative to those aged 15–29 years (adjusted odds ratio [OR], 1.41; 95% CI, 1.25–1.60); in males, relative to females (adjusted OR, 1.17; 95% CI, 1.10–1.24); in individuals in rural areas, relative to those in urban areas (adjusted OR, 1.44; 95% CI, 1.28–1.63); and in the dry season, relative to the rainy season (adjusted OR, 1.54; 95% CI, 1.37–1.75). Forty-eight percent of isolates had genes encoding disease-associated polysaccharide capsules; genogroup W predominated, and genogroup A was rare. Strain diversity was lower in countries in the center of the meningitis belt than in Senegal or Ethiopia. The prevalence of genogroup A fell from 0.7% to 0.02% in Chad following mass vaccination with MenAfriVac.Conclusions. The prevalence of meningococcal carriage in the African meningitis belt is lower than in industrialized countries and is very diverse and dynamic, even in the absence of vaccination.

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ObjectiveDetection of meningococcal carriers is key to understanding the epidemiology of Neisseria meningitidis, yet no gold standard has been established. Here, we directly compare two methods for collecting pharyngeal swabs to identify meningococcal carriers.MethodsWe conducted cross-sectional surveys of schoolchildren at multiple sites in Africa to compare swabbing the posterior pharynx behind the uvula (U) to swabbing the posterior pharynx behind the uvula plus one tonsil (T). Swabs were cultured immediately and analyzed using molecular methods.ResultsOne thousand and six paired swab samples collected from schoolchildren in four countries were analyzed. Prevalence of meningococcal carriage was 6.9% (95% CI: 5.4-8.6%) based on the results from both swabs, but the observed prevalence was lower based on one swab type alone. Prevalence based on the T swab or the U swab alone was similar (5.2% (95% CI: 3.8-6.7%) versus 4.9% (95% CI: 3.6-6.4%) respectively (p=0.6)). The concordance between the two methods was 96.3% and the kappa was 0.61 (95% CI: 0.50-0.73), indicating good agreement.ConclusionsThese two commonly used methods for collecting pharyngeal swabs provide consistent estimates of the prevalence of carriage, but both methods misclassified carriers to some degree, leading to underestimates of the prevalence.

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This study showed high costs and few life-years gained for the dominant strategy even for the more favourable risk group. New studies may be carried out for new screening and therapeutic strategies.

Nosocomial transmission of viral and bacterial infections is a major problem worldwide, affecting millions of patients (and causing hundreds of thousands of deaths) per year. Rotavirus infections affect most children worldwide at least once before age five. We present here deterministic and stochastic models for the transmission of rotavirus in a pediatric hospital ward and draw on published data to compare the efficacy of several possible control measures in reducing the number of infections during a 90-day outbreak, including cohorting, changes in healthcare worker-patient ratio, improving compliance with preventive hygiene measures, and vaccination. Although recently approved vaccines have potential to curtail most nosocomial rotavirus transmission in the future, even short-term improvement in preventive hygiene compliance following contact with symptomatic patients may significantly limit transmission as well, and remains an important control measure, especially where resources are limited.

The aim of this study was to evaluate the Chiron branched DNA (bDNA) assay for detection of serum hepatitis B virus (HBV) DNA in patients with chronic hepatitis B lacking hepatitis B e antigen (HBeAg) and undergoing interferon (IFN) therapy. Results obtained with the bDNA assay were compared with those obtained using the Abbott liquid hybridization (LH) assay and the polymerase chain reaction (PCR). Serial samples (274) from 34 patients were analysed. Analysis of variance results indicated that bDNA values were more significantly correlated than LH values with both PCR positive/negative results (probability of artifact (Prob > F) = 0.7 and 0.09 for LH and bDNA assays, respectively) and presence/absence of precore mutations (Prob > F = 0.21 and 0.001 for LH and bDNA assays, respectively). Both bDNA and LH results correlated highly with alanine aminotransferase (ALT) values (both had Prob > F values of 0.0) while PCR was not correlated with ALT (Prob > F = 0.05). In 26 evaluable patients, a model based on a generalized Knodell score was used to predict response to IFN therapy, as defined by normalization of ALT values during therapy. This model discriminated well between non-responders and responders. The bDNA results correlated well with the generalized Knodell score, while the LH results did not (Prob > F = 0.04 and 0.19 for the bDNA and LH assays, respectively). In conclusion, the bDNA assay appears to be useful for quantification of HBV DNA levels in HBeAg-negative chronic hepatitis as it correlates with biochemical and histological indications of disease severity as well as with response to IFN therapy.

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