ABSTRACT
Cellulitis is an acute bacterial infection of the dermis and subcutaneous tissue usually found complicating a wound, ulcer, or dermatosis. This article provides guidelines for the surveillance of cellulitis. The primary objectives of cellulitis surveillance are to (1) monitor trends in rates of infection, (2) describe the demographic and clinical characteristics of patients with cellulitis, (3) estimate the frequency of complications, and (4) describe the risk factors associated with primary and recurrent cellulitis. This article includes case definitions for clinical cellulitis and group A streptococcal cellulitis, based on clinical and laboratory evidence, and case classifications for an initial and recurrent case. It is expected that surveillance for cellulitis will be for all-cause cellulitis, rather than specifically for Strep A cellulitis. Considerations of the type of surveillance are also presented, including identification of data sources and surveillance type. Minimal surveillance necessary for cellulitis is facility-based, passive surveillance. Prospective, active, facility-based surveillance is recommended for estimates of pathogen-specific cellulitis burden. Participant eligibility, surveillance population, and additional surveillance considerations such as active follow-up of cases, the use of International Classification of Disease diagnosis codes, and microbiological sampling of cases are discussed. Finally, the core data elements to be collected on case report forms are presented.
ABSTRACT
Background: Contemporary data for the global burden of sore throat and group A Streptococcus (Strep A) pharyngitis are required to understand the frequency of disease and develop value propositions for Strep A vaccines. Methods: We used Clarivate Analytics' Web of Science platform to search WoS core collection, PubMed, Medline, data citation index, KCI-Korean Journal Database, Russian Science Citation Index, and the SciELO Citation Index for articles published between Jan 1, 2000, and Feb 15, 2021, from any country and in any language. The risk of bias was assessed using the JBI critical appraisal checklist. We used random-effects meta-analyses to pool sore throat and Strep A sore throat incidence rates from community-based studies. Our study was registered with PROSPERO (CRD42020181103). Findings: Of 5,529 articles identified by the search strategy, 26 studies met the inclusion criteria, but only two included data to determine incidence among adults. The pooled incidence rate, calculated for children only, was 82.2 episodes per 100 child-years (95% CI 25.2-286.3, I2 = 100%) for sore throat (7 studies; 7,964 person years) and 22.1 episodes per 100 child-years (95% CI 14.7-33.1, I2 = 98%) for Strep A sore throat (9 studies; 15,696 person years). The pooled cumulative incidence rate of sore throat from five studies was 31.9 per 100 children. There was significant methodological and statistical heterogeneity among studies, and five of 26 studies had a risk of bias score less than five (range: nine [maximum score] to one). Interpretation: Strep A sore throat has a considerable global burden. However, methodologically standardised studies are required to quantify that burden, analyse differences in rates between populations, and evaluate the likely impact of future Strep A vaccines. Funding: This study was funded by Wellcome Trust 215,490/Z/19/Z.
ABSTRACT
Genetic manipulation of Streptococcus pyogenes (Group A Streptococcus, GAS) has historically been a challenging process, with considerable variation in efficiency between different strains. Here, we outline an optimized, rapid method for creating markerless isogenic mutations that combines Gibson assembly cloning with a new temperature-sensitive plasmid, pLZts. This method is highly efficient and reduces the time needed to create GAS mutants to ~2-3 weeks, with the ability to prepare multiple mutants simultaneously.
