pneumococcal
not annotated - annotated - LINNAEUS only
21272792
Effective management in clusters of pneumococcal disease: a systematic review.
Outbreaks of serious pneumococcal disease can occur with high attack rates in certain settings. We systematically reviewed studies of interventions implemented in pneumococcal clusters and those reporting the effect of antibiotics on carriage reduction to assess the effectiveness of interventions. Evidence was graded according to the Scottish Intercollegiate Guidelines Network system. Of 28 identified cluster reports, one showed that administration of antibiotics to close contacts reduced risk of pneumococcal disease. In three of four clusters where rifampicin chemoprophylaxis was used and in four of five clusters where penicillin was used no further cases were seen after intervention. In clusters where pneumococcal polysaccharide vaccine was used, subsequent cases occurred, all within around 2 weeks of vaccination, which suggests delayed benefit with this approach (evidence grade D). Use of infection control measures alone was reported in eight clusters, with no further cases being reported in seven (grade D). From 21 selected carriage studies, large carriage reductions were observed consistently with use of penicillin and azithromycin, with median values being 90% and 73%, respectively (grade C). The findings were presented to a working group for pneumococcal cluster guidelines and used to develop key recommendations on the management of clusters that supported prompt use of amoxicillin or azithromycin chemoprophylaxis, pneumococcal vaccination for close contacts, and implementation of infection control measures.
21492929
Serotype replacement in disease after pneumococcal vaccination.
Vaccination with heptavalent pneumococcal conjugate vaccine (PCV7) has significantly reduced the burden of pneumococcal disease and has had an important public health benefit. Because this vaccine targets only seven of the more than 92 pneumococcal serotypes, concerns have been raised that non-vaccine serotypes (NVTs) could increase in prevalence and reduce the benefits of vaccination. Indeed, among asymptomatic carriers, the prevalence of NVTs has increased substantially, and consequently, there has been little or no net change in the bacterial carriage prevalence. In many populations, pneumococcal disease caused by NVT has increased, but in most cases this increase has been less than the increase in NVT carriage. We review the evidence for serotype replacement in carriage and disease, and address the surveillance biases that might affect these findings. We then discuss possible reasons for the discrepancy between near-complete replacement in carriage and partial replacement for disease, including differences in invasiveness between vaccine serotypes. We contend that the magnitude of serotype replacement in disease can be attributed, in part, to a combination of lower invasiveness of the replacing serotypes, biases in the pre-vaccine carriage data (unmasking), and biases in the disease surveillance systems that could underestimate the true amount of replacement. We conclude by discussing the future potential for serotype replacement in disease and the need for continuing surveillance.