Group A Streptococcus Carriage Research Articles

Leveraging School Health Programs in Africa: Integrated Screening for Rheumatic Heart Disease and Dental Caries.

Rheumatic heart disease (RHD) and dental caries (DC) disproportionately affect children and young adults in sub-Saharan countries, with major impact on schoolchildren's health and education. DC in children with RHD constitutes an important risk for fatal complications. Our study aimed at assessing the feasibility of simultaneous RHD and DC screening in school environment. March 20-24, 2022, we performed an observational descriptive study of schoolchildren in a public school in Maputo City, Mozambique. RHD screening involved two stages: first, a physical examination (including cardiac auscultation and direct observation of the oral cavity), and second, an abbreviated echocardiography performed by a cardiologist. Rapid testing for group A Streptococcus (GAS) was done to every eighth child in the classroom and for those with signs suggesting recent infection, in accordance with the study protocol developed for screening. A multidisciplinary team collected the data. Data were analyzed using descriptive statistics. A total of 954 students (median age 9; range 6-15) were screened. One hundred and twenty-five participants were eligible for a rapid antigen test, of which 6 (4.8%) tested positive. On clinical evaluation 52 children (5.3%) presented a heart murmur. Echocardiography on 362 children showed borderline RHD in 35 children and definite RHD in 2 (0.6%); 1 child had a ventricular septal defect. Dental cavities were present in 444 (48.4%), despite 904 out of 917 students reporting brushing of their teeth once to three times daily (98.6%). School-based integrated oral and cardiovascular screenings and use of rapid tests for GAS carriage provide crucial information to create customized preventive strategies for rheumatic fever (RF) and RHD in low- and middle-income countries (LMICs), in addition to detecting children at very high risk of bacterial endocarditis. The sustainability of such interventions and acceptability by health providers needs to be assessed.

Time to negative throat culture following initiation of antibiotics for pharyngeal group A Streptococcus: a systematic review and meta-analysis up to October 2021 to inform public health control measures.

BackgroundPublic health guidance recommending isolation of individuals with group A streptococcal (GAS) infection or carriage for 12-24 h from antibiotic initiation to prevent onward transmission requires a strong evidence base.AimTo estimate the pooled proportion of individuals who remain GAS culture-positive at set intervals after initiation of antibiotics through a systematic literature review (PROSPERO CRD42021290364) and meta-analysis.MethodsWe searched Ovid MEDLINE (1946-), EMBASE (1974-) and Cochrane library. We included interventional or observational studies with ≥ 10 participants reporting rates of GAS throat culture positivity during antibiotic treatment for culture-confirmed GAS pharyngitis, scarlet fever and asymptomatic pharyngeal GAS carriage. We did not apply age, language or geographical restrictions.ResultsOf 5,058 unique records, 43 were included (37 randomised controlled studies, three non-randomised controlled trials and three before-and-after studies). The proportion of individuals remaining culture-positive on day 1, day 2 and days 3-9 were 6.9% (95% CI: 2.7-16.8%), 5.4% (95% CI: 2.1-13.3%) and 2.6% (95% CI: 1.6-4.2%). For penicillins and cephalosporins, day 1 positivity was 6.5% (95% CI: 2.5-16.1%) and 1.6% (95% CI: 0.04-42.9%), respectively. Overall, for 9.1% (95% CI: 7.3-11.3), throat swabs collected after completion of therapy were GAS culture-positive. Only six studies had low risk of bias.ConclusionsOur review provides evidence that antibiotics for pharyngeal GAS achieve a high rate of culture conversion within 24 h but highlights the need for further research given methodological limitations of published studies and imprecision of pooled estimates. Further evidence is needed for non-beta-lactam antibiotics and asymptomatic individuals.

Prevalence of group A streptococcal carriage in school children from Cape Town: A cross- sectional study and systematic review


 
 
 
 Background. Asymptomatic children can be a major reservoir of pharyngeal group A streptococcus (GAS). The role of GAS carriage causing subsequent infections resulting in the manifestation of clinical symptoms, or being associated with transmission to uninfected individuals, is not entirely clear. Furthermore, data on GAS carriage from countries in Africa remain scant with only a few studies reporting carriage.
 Objectives. We performed a cross-sectional study to determine the prevalence of asymptomatic pharyngeal carriage of group A streptococci in school children in Cape Town. We considered our results in the context of a meta-analysis of data of GAS carriage in Africa.
 Methods. We conducted a school-based cross-sectional study from 2009 to 2011 in two Cape Town peri-urban communities, enrolling 950 healthy learners. Pharyngeal swabs were obtained from learners and processed at the National Health Laboratory Service (NHLS) microbiology laboratory at Groote Schuur Hospital, Cape Town. Thereafter, we conducted a systematic review through a comprehensive literature search among several sources. Prevalence estimates with 95% confidence intervals (CIs) were determined using a random-effects meta-analysis model.
 Results. GAS was isolated from 31 participants corresponding to a carrier rate of 3% (95% CI 2% - 4%). Combining our results with 18 other studies revealed a pooled prevalence of 9% (95% CI 6% - 11%). Regional pooled rates were similar across southern, eastern and northern Africa, of between 9% (95% CI 6% - 11%) and 11% (95% CI 4% - 21%) while countries within Central Africa had a pooled estimate of 7% (95% CI 5% - 9%). Western Africa had the lowest pooled estimate of 2% (95% CI 1% - 2%).
 Conclusion. There was a relatively low rate of carriage of GAS in asymptomatic school children residing in South Africa. Pooled prevalence rates revealed regional differences across the African continent as regards the rate of GAS carriage, with the western and northern African regions having rates of GAS carriage that were lower and higher respectively than those of East, Central and southern African countries, which demonstrated similar rates of carriage.
 
 
 

Low rate of asymptomatic carriage and salivary immunoglobulin A response to Group A Streptococci in the healthy adult population in Finland

Streptococcus pyogenes, also called group A streptococcus (GAS), is a human pathogen causing a wide range of infections ranging from mild tonsillitis to severe, life threatening conditions such as bacteraemia, necrotizing fasciitis, and streptococcal toxic shock syndrome. GAS may also colonise the oropharynx without causing any signs of disease which is known as asymptomatic carriage. This study aims to investigate IgA responses against GAS and oral streptococci from saliva samples collected from healthy Finnish adults. In addition, asymptomatic throat GAS carriage was studied. The study participants consisted of healthy adult volunteers who provided one saliva sample, a throat swab, and a background questionnaire. Total salivary IgA, and GAS specific IgA were analysed from the saliva samples using enzyme-linked immunosorbent assays (ELISA) and the results were compared to oral streptococci specific IgA levels. Asymptomatic GAS throat carriers were identified by bacterial culture, and the isolates were emm typed. Samples from a total of 182 individuals were analysed. The median salivary IgA concentration was 62.9 µg/ml (range 17.3–649.9 µg/ml), and median GAS and oral streptococcal specific IgA concentrations 2.7 and 3.3 arbitrary units (AU, range 1.4–7.4 AU and 1.6–12.0 AU), respectively. Three individuals with asymptomatic GAS throat carriage were identified.

Three sequential outbreaks of Group A Streptococcus over a two-year period at the Canadian Forces Leadership and Recruit School, St. Jean Garrison, Québec.

Since December 2016, the basic military training (BMT) facility for the Canadian Armed Forces (CAF) has experienced repeated outbreaks of Group A Streptococcus (GAS). In 2018, a voluntary mass antibiotic prophylaxis (MAP) program was implemented to interrupt GAS transmission among recruits. The objective of this study was to describe the epidemiology of three GAS outbreaks and a period of increased pharyngitis infections at the CAF BMT facility in Québec over a two-year span, and to detail the prevention and control measures implemented to mitigate the risk to recruit health. Descriptive data were collected on invasive and severe GAS cases along with laboratory data including genotyping of throat swabs from recruits presenting with pharyngitis. A laboratory-based acute respiratory infection surveillance system was used to aid in monitoring and decision-making. Close contacts of recruits were assessed for asymptomatic GAS carriage and MAP adverse events surveillance was conducted. Three distinct GAS outbreaks occurred at the Canadian Forces Leadership and Recruit School totaling eight invasive (iGAS) and 13 severe (sGAS) cases over two years. All iGAS/sGAS cases, apart from one instructor, were among recruits. The predominant strain in all three outbreaks was type emm6.4. A total of 11,293 recruits received MAP (penicillin G benzathine or azithromycin) between March 7, 2018 and November 18, 2019. There were eight reported serious adverse events related to penicillin administration. The CAF BMT facility experienced three GAS outbreaks over the course of two years, and despite the use of enhanced hygiene measures, only MAP has been effective in quelling these outbreaks.

Increase of emm1 isolates among group A Streptococcus strains causing scarlet fever in Shanghai, China

ObjectiveScarlet fever epidemics caused by group A Streptococcus (GAS) have been ongoing in China since 2011. However, limited data are available on the dynamic molecular characterizations of the epidemic strains. MethodEpidemiological data of scarlet fever in Shanghai were obtained from the National Notifiable Infectious Disease Surveillance System. Throat swabs of patients with scarlet fever and asymptomatic school-age children were cultured. Illumina sequencing was performed on 39emm1 isolates. ResultsThe annual incidence of scarlet fever was 7.5–19.4/100,000 persons in Shanghai during 2011–2015, with an average GAS carriage rate being 7.6% in school-age children. The proportion ofemm1 GAS strains increased from 3.8% in 2011 to 48.6% in 2014; they harbored a superantigen profile similar to emm12 isolates, except for the speA gene. Two predominant clones, SH001-emm12, and SH002-emm1, circulated in 66.9% of scarlet fever cases and 44.8% of carriers. Genomic analysis showed emm1 isolates throughout China constituted distinct clades, enriched by the presence of mobile genetic elements carrying the multidrug-resistant determinants ermB and tetM and virulence genes speA, speC, and spd1. ConclusionA significant increase in the proportion ofemm1 strains occurred in the GAS population, causing scarlet fever in China. Ongoing surveillance is warranted to monitor the dynamic changes of GAS clones.

2185. Group A Streptococcus (GAS) Detection by PCR in Children with Viral Acute Respiratory Illness and Healthy Children

BackgroundAcute pharyngitis is mostly of viral etiology; GAS, the leading bacterial cause, comprises 20%–30% of pediatric pharyngitis. Patients with pharyngitis and additional acute respiratory illness (ARI) symptoms more suggestive of viral etiology, including cough, rhinorrhea and conjunctivitis, are not recommended for GAS testing. The use of highly sensitive GAS PCR assays in patients with sore throat and viral ARI symptoms may detect GAS colonization and lead to antibiotic overuse. We evaluated GAS PCR in viral ARI inpatients and asymptomatic healthy controls (HC) to illustrate the potential negative impact of offering GAS PCR test in poorly selected patients.MethodsIn November 2015–June 2016, 458 ARI inpatients (< 18 years) and 205 HC (< 5 years, no ARI symptoms within 72 hours) in Kansas City were enrolled in the New Vaccine Surveillance Network study. Mid-turbinate and throat swabs were tested by multiplex respiratory panel PCR and leftover nucleic acid extracts were further tested by real-time GAS PCR. Presenting symptoms of cough, rhinorrhea and/or conjunctivitis, plus sore throat were assessed by parent interview.ResultsOverall, 6.3% of HC < 5 years old and 8.7% of ARI subjects < 18 years were GAS (+); mostly in the 3–15 year old age group (25/40, 62.5%). Among 3–15 year old GAS (+) ARI subjects, 92.8% had cough, 76.2% rhinorrhea and 37.2% conjunctivitis; 80% had > 2 of 3 symptoms noted above. Among 40 GAS (+) ARI subjects, a virus was co-detected in 34 (85%), among which Rhinovirus/Enterovirus were predominant 22/34 (55%). Of the 130 (28%) ARI subjects with sore throat, more tested positive for viruses (107/130, 82.3%) than for GAS (9/130, 6.9%). All GAS (+) HC (13/205, 6.3% overall) were < 3 year olds.ConclusionPCR detected GAS in 6.3% HC < 5 years old and 8.7% ARI subjects < 18 years old; mostly in 3- to 15-year-old ARI subjects. Most GAS (+) ARI children had cough, rhinorrhea or conjunctivitis and/or virus co-detection suggesting GAS carriage. Our data demonstrate that GAS may be detected in patients with a low clinical suspicion for acute GAS pharyngitis. These findings highlight the need to review patient selection and exercise caution in implementing highly sensitive GAS PCR assays especially in such clinical settings. Disclosures All authors: No reported disclosures.

An Experimental Group A Streptococcus Vaccine That Reduces Pharyngitis and Tonsillitis in a Nonhuman Primate Model.

Group A Streptococcus (GAS) infections account for an estimated 500,000 deaths every year. This bacterial pathogen is responsible for a variety of mild and life-threatening infections and the triggering of chronic autoimmune sequelae. Pharyngitis caused by group A Streptococcus (GAS), but not asymptomatic GAS carriage, is a prerequisite for acute rheumatic fever (ARF). Repeated bouts of ARF may trigger rheumatic heart disease (RHD), a major cause of heart failure and stroke accounting for 275,000 deaths annually. A vaccine that prevents pharyngitis would markedly reduce morbidity and mortality from ARF and RHD. Nonhuman primates (NHPs) have been utilized to model GAS diseases, and experimentally infected rhesus macaques develop pharyngitis. Here we use an NHP model of GAS pharyngitis to evaluate the efficacy of an experimental vaccine, Combo5 (arginine deiminase [ADI], C5a peptidase [SCPA], streptolysin O [SLO], interleukin-8 [IL-8] protease [SpyCEP], and trigger factor [TF]), specifically designed to exclude GAS components potentially linked to autoimmune complications. Antibody responses against all Combo5 antigens were detected in NHP serum, and immunized NHPs showed a reduction in pharyngitis and tonsillitis compared to controls. Our work establishes the NHP model as a gold standard for the assessment of GAS vaccines.IMPORTANCE GAS-related diseases disproportionally affect disadvantaged populations (e.g., indigenous populations), and development of a vaccine has been neglected. A recent strong advocacy campaign driven by the World Health Organization and the International Vaccine Institute has highlighted the urgent need for a GAS vaccine. One significant obstacle in GAS vaccine development is the lack of a widely used animal model to assess vaccine efficacy. Researchers in the field use a wide range of murine models of infection and in vitro assays, sometimes yielding conflicting results. Here we present the nonhuman primate pharyngeal infection model as a tool to assess vaccine-induced protection against colonization and clinical symptoms of pharyngitis and tonsillitis. We have tested the efficacy of an experimental vaccine candidate with promising results. We believe that the utilization of this valuable tool by the GAS vaccine research community could significantly accelerate the realization of a safe and effective GAS vaccine for humans.

Risk factors, clinical course and outcomes of pregnancy-related group A streptococcal infections: retrospective 13-year cohort study

ObjectivesTo investigate the incidence, risk factors, clinical course and outcomes of pregnancy-related group A streptococcus (GAS) infection. MethodsA retrospective 13-year cohort study of culture-proven pregnancy-related GAS infection was performed at two university hospitals serving heterogeneous, multicultural, urban and rural populations. ResultsOf 124 women diagnosed with pregnancy-related GAS infection, 115 (93%) were in the puerperium, an incidence of 0.8 cases per 1000 live births (95% confidence interval, 0.7–0.9). A multivariate analysis showed primiparity and cesarean delivery to be independent protective factors against puerperal GAS infection (adjusted odds ratios (95% confidence interval), 0.60 (0.38, 0.97) and 0.44 (0.23, 0.81), respectively). Of the nine remaining patients, eight were diagnosed after first trimester abortions and one had an infected ectopic pregnancy. Among the entire cohort (n = 124), the predominant manifestations were fever and abdominal tenderness. Twenty-eight patients (23%) had severe GAS infections. All were treated with β-lactams, and most (n = 104, 84%) received clindamycin. Only four (3%) required surgical intervention; the rest fully recovered with conservative medical treatment including antibiotics. No recurrences, maternal deaths or neonatal complications were noted. ConclusionsPregnancy-related GAS infection is not rare; it lacks specific signs and still carries significant morbidity. Primiparity, a presumable surrogate for diminished exposure to children and thus less GAS carriage, and cesarean delivery in which perioperative antibiotic prophylaxis was uniformly provided, appear as protective factors against puerperal GAS infection. This hints to the importance of community-acquired GAS and may support shifting efforts from infection-control–oriented nosocomial investigations to screening and prevention–driven policies.

Outbreak of invasive group A streptococcus: investigations using agar settle plates detect perineal shedding from a healthcare worker

Outbreaks of group A streptococcus (GAS) infections may occur in healthcare settings. Transmission to patients is sometimes linked to colonized healthcare workers (HCWs) and/or a contaminated environment. To describe the investigation and control of an outbreak of healthcare-associated GAS on an elderly care medical ward, over six months. Four patients developed septicaemia due to GAS infection without a clinically obvious site of infection. The outbreak team undertook an investigation involving a retrospective review of GAS cases, prospective case finding, HCW screening and environmental sampling using both swabs and settle plates. Immediate control measures included source isolation and additional cleaning of the ward environment with a chlorine disinfectant and hydrogen peroxide. Prospective patient screening identified one additional patient with throat GAS carriage. Settle plate positivity for GAS was strongly associated with the presence of one individual HCW on the ward, who was subsequently found to have GAS perineal carriage. Contamination of a fabric-upholstered chair in an office adjacent to the ward, used by the HCW, was also detected. In total, three asymptomatic HCWs had throat GAS carriage and one HCW had both perineal and throat carriage. All isolates were typed as emm 28. This is the first outbreak report demonstrating the use of settle plates in a GAS outbreak investigation on a medical ward, to identify the likely source of the outbreak. Based on this report we recommend that both throat and perineal sites should be sampled if HCW screening is undertaken during an outbreak of GAS. Fabric, soft furnishings should be excluded from clinical areas as well as any adjacent offices because pathogenic bacteria such as GAS may contaminate this environment.

Group A Streptococcus pharyngitis and pharyngeal carriage: A meta-analysis.

ObjectiveAntibiotic treatment of Group A Streptococcus (GAS) pharyngitis is important in acute rheumatic fever (ARF) prevention, however clinical guidelines for prescription vary. GAS carriers with acute viral infections may receive antibiotics unnecessarily. This review assessed the prevalence of GAS pharyngitis and carriage in different settings.MethodsA random-effects meta-analysis was performed. Prevalence estimates for GAS+ve pharyngitis, serologically-confirmed GAS pharyngitis and asymptomatic pharyngeal carriage were generated. Findings were stratified by age group, recruitment method and country income level. Medline and EMBASE databases were searched for relevant literature published between 1 January 1946 and 7 April 2017. Studies reporting prevalence data on GAS+ve or serologically-confirmed GAS pharyngitis that stated participants exhibited symptoms of pharyngitis or upper respiratory tract infection (URTI) were included. Included studies reporting the prevalence of asymptomatic GAS carriage needed to state participants were asymptomatic.Results285 eligible studies were identified. The prevalence of GAS+ve pharyngitis was 24.1% (95% CI: 22.6–25.6%) in clinical settings (which used ‘passive recruitment’ methods), but less in sore throat management programmes (which used ‘active recruitment’, 10.0%, 8.1–12.4%). GAS+ve pharyngitis was more prevalent in high-income countries (24.3%, 22.6–26.1%) compared with low/middle-income countries (17.6%, 14.9–20.7%). In clinical settings, approximately 10% of children swabbed with a sore throat have serologically-confirmed GAS pharyngitis, but this increases to around 50–60% when the child is GAS culture-positive. The prevalence of serologically-confirmed GAS pharyngitis was 10.3% (6.6–15.7%) in children from high-income countries and their asymptomatic GAS carriage prevalence was 10.5% (8.4–12.9%). A lower carriage prevalence was detected in children from low/middle income countries (5.9%, 4.3–8.1%).ConclusionsIn active sore throat management programmes, if the prevalence of GAS detection approaches the asymptomatic carriage rate (around 6–11%), there may be little benefit from antibiotic treatment as the majority of culture-positive patients are likely carriers.

An emm5 Group A Streptococcal Outbreak Among Workers in a Factory Manufacturing Telephone Accessories.

Ranked among the top10 infectious causes of death worldwide, group A Streptococcus (GAS) causes small- and large-scale outbreaks, depending on the trigger as transmission of a GAS strain or expansion of predominant clones. In China, GAS infections other than scarlet fever are not notifiable. In Shanghai, an epidemiological investigation was initiated after two successive severe pneumonia cases with one death in a digital factory, from where outbreaks are less widely reported. The investigation was performed using emm typing, pulsed-field gel electrophoresis (PFGE) typing, superantigen profiling, and genome analysis. This enabled characterization of relatedness among the outbreak isolates and identification of the mobile genetic elements present. Among 57 patients with respiratory symptoms investigated in the factory, emm5 GAS strains were isolated from 8 patients. The eight GAS infection cases comprising one fatal severe pneumonia case, six influenza-like illness cases, and one pharyngitis case. Two risk factors were identified: adult with an age of 18–20 years and close contact with a GAS patient or carrier. GAS attack rate was 14.0% (8/57), and GAS carriage rate was probably around 2.7% (14/521) based on surveys in two nearby districts. All the 10 outbreak associated isolates were assigned to emm5 and sequence type ST-99 (emm5/ST-99), harbored superantigen genes speC, speG, and smeZ, and were assigned to two similar PFGE patterns (clones). Among the outbreak associated isolates, all carried ermA with resistance to erythromycin and inducible resistance to clindamycin, and eight (80%) carried a tetM gene with resistance to tetracycline. Among the 14 carriage isolates, 12 were emm12/ST-36, and 2 were emm1/ST-28, all with superantigen genes speC, speG, ssa, and smeZ. All the carriage isolates harbored ermB and tetM with resistance to erythromycin, clindamycin, and tetracycline. Genome analysis showed the two outbreak clones were closely related and possessed new prophages carrying virulence gene sdc and antibiotic resistance genes of ermA and tetM, which were not found in the emm5 reference strain Manfredo. This is the first report of a GAS outbreak in this type of workplace. The outbreak was caused by two closely related emm5 clones that differed from the predominant emm types circulating in China.

Prevalence of group a streptococcus pharyngeal carriage and clinical manifestations in school children aged 5\u201315\xa0yrs in Wakiso District, Uganda

BackgroundBeta-hemolytic streptococci carrier rates in children living in low-income countries are high ranging from 10 to 50%. Although most of these children are asymptomatic, they are a reservoir and pose a risk of transmission. The aim of this study was to determine the prevalence of group a streptococcus pharyngeal carriage and clinical manifestations in school going children in Wakiso district, Uganda.MethodsA cross sectional study targeting children age 5–15 years in primary schools in one sub-county of Wakiso district was carried out. Three hundred and sixty-six children from five primary schools were enrolled and evaluated for group a streptococcus (GAS) carriage. A semi-structured questionnaire was used to collect data that included social demographics, school environment and clinical findings. For every enrolled child a throat swab was taken and cultured for GAS and blood was drawn for anti-streptolysin-O titres. Analysis of data was done using STATA.ResultsThe prevalence of GAS carriage was 16%. The children with GAS positive cultures were mainly females. The factor associated with GAS carriage was the school location, with peri-urban schools more likely to have children with GAS compared to rural schools; AOR 2.48 (95% CI: 1.01 – 6.11), P = 0.049. There was no significant difference between the characteristic of children with GAS positive verses GAS negative throat swab cultures.ConclusionThere is a high prevalence of GAS pharyngeal carriage among children aged 5–15 years attending primary schools in Wakiso District, Uganda.

Asymptomatic group A Streptococcal throat carriage in Royal Marines recruits and Young Officers

A prospective observational study was conducted in Royal Marines (RM) recruits to investigate throat carriage of group A Streptococcus (GAS) and incidence of soft tissue infections. 1012 RM recruits were followed through a 32-week training programme, with throat swabs being obtained in weeks 1, 6, 15, and 32. Alongside a separate cohort of 46 RM Young Officers (YO) undergoing training were sampled in parallel. Carriage of group A Streptococcus was detected in only 5/1012 (0.49%) recruits at the beginning of training and remained low throughout training. There was no association between GAS carriage and development of soft tissue infection. There was no carriage of GAS in the smaller YO cohort at the start of training, (0/46). At week 6, a surge in GAS carriage was detected in 8/46 (17%) YO, that could be ascribed to a cluster of GAS genotype emm83. Asymptomatic GAS carriage is very infrequent among young adults in England and this should be borne in mind when considering the relevance of a positive throat swab result in symptomatic patients or outbreaks. Despite low prevalence, there is however potential for GAS to rapidly and transiently disseminate among adults during outbreaks.

Clinical and epidemiological aspects of streptococcus pyogenes pharyngitis and carriage in Africa

Infection with Group A β-haemolytic Streptococcus, also known as Streptococcus pyogenes, results in various mucosal and skin diseases including pharyngitis. An exaggerated immune response to a single or repeated group A streptococcal (GAS) infection subsequently results in acute rheumatic fever (ARF) and, in the absence of intervention, repeated bouts of ARF may in turn result in progression to RHD, particularly in those ARF patients with cardiac involvement. Addressing GAS pharyngitis through appropriate primary prevention measures and treating all symptomatic GAS sore throats with a course of oral or parenteral penicillin presents an opportunity for the primary intervention of RHD. Failure to eradicate streptococci from the pharynx occurs in about one third of non-treated cases, giving rise to carrier status in those individuals harbouring intracellular GAS and thus representing a potential source of the acquisition of infections for other children and adults. Improved living conditions and access to healthcare during the last century are credited for the considerable decline in the prevalence of ARF and RHD in developed countries. However, a few studies have been reported from within Africa, and in these GAS carriage ranged around 9.0%. In South African studies GAS carriage isolation rates, which range from 1.62% to16.8%, were reported. As regards the prevalence of GAS pharyngitis, it is generally higher in developing countries and impoverished communities within industrialised nations. The most-up-to-date data from South Africa was collected more than 30 years ago with rates then ranging from 23.2% to 45.5%. There are no incidence data on GAS pharyngitis in Africa. This review found that there is a need to document the epidemiology of GAS carriage and GAS pharyngitis in school children of all ages within Africa. Molecular characterisation of strains harboured in the pharynx of carriers and of those isolated during bouts of pharyngitis, will help to identify risk factors associated with carriage in school-aged children and infl uence the planning and evaluation of management programmes in the screening of pharyngeal carriers and treatment of GAS pharyngitis.

Outbreak of group A Streptococcus infections in an outpatient wound clinic-Colorado, 2014.

In September 2014, wound clinic A reported a cluster of group A Streptococcus (GAS) infections to public health authorities. Although clinic providers were individually licensed, the clinic, affiliated with hospital A, was not licensed or subject to regulation. We investigated to identify cases, determine risk factors, and implement control measures. A case was defined as GAS isolation from a wound or blood specimen during March 28-November 19, 2014, from a patient treated at wound clinic A or by a wound clinic A provider within the previous 7 days. All wound clinic A staff were screened for GAS carriage. Wound care procedures were assessed for adherence to infection control principles and possible GAS transmission routes. We identified 16 patients with 19 unique infections: 9 (56%) patients required hospitalization, and 7 (44%) required surgical debridement procedures. One patient died. Six (37%) patients received negative pressure wound therapy at GAS onset. Staff self-screening found no GAS carriers. Breaches in infection control and poor wound care practices were widespread. This GAS outbreak was associated with a wound care clinic not subject to state or federal regulation. Lapses in infection control practices and inadequate oversight contributed to the outbreak.

MANAGEMENT OF CLINICALLY CURED TONSILLOPHARYNGITIS IN PATIENTS WITH GROUP A STREPTOCOCCUS ISOLATED FROM A PHARYNGEAL SWAB

The group A streptococcus (GAS) tonsillopharyngitis is a very common disease in children’s age. Inappropriate use of antibiotics is frequently encountered, both for treatment purposes and for eradication of the causative agents. The aim of our study was to discover reasons and causes for inappropriate use of antibiotics in children. We have used the triangulation approach to the problem which was studied by the analysis of interviews, observation of patient-cases and by the review of medical records. We discovered that prescribers had very different attitudes towards curing GAS tonsillopharyngitis as well as towards curing GAS carriage. The physicians were under the pressure to prescribe antibiotics and the parents were prone to administer antibiotics to children by themselves. Such behavior could be partially explained by the lack of funds for laboratory analyses. Moreover, the patients were still allowed to buy antibiotics without prescriptions. General culture of using antibiotics should be increased to a higher level among both health workers and parents in order to change some irrational behavior when managing patients who have been cured from streptococcal tonsillopharyngitis. Acta Medica Medianae 2015;54(4):46-51.

Natural variant of collagen-like protein a in serotype M3 group a Streptococcus increases adherence and decreases invasive potential.

Group A Streptococcus (GAS) predominantly exists as a colonizer of the human oropharynx that occasionally breaches epithelial barriers to cause invasive diseases. Despite the frequency of GAS carriage, few investigations into the contributory molecular mechanisms exist. To this end, we identified a naturally occurring polymorphism in the gene encoding the streptococcal collagen-like protein A (SclA) in GAS carrier strains. All previously sequenced invasive serotype M3 GAS possess a premature stop codon in the sclA gene truncating the protein. The carrier polymorphism is predicted to restore SclA function and was infrequently identified by targeted DNA sequencing in invasive strains of the same serotype. We demonstrate that a strain with the carrier sclA allele expressed a full-length SclA protein, while the strain with the invasive sclA allele expressed a truncated variant. An isoallelic mutant invasive strain with the carrier sclA allele exhibited decreased virulence in a mouse model of invasive disease and decreased multiplication in human blood. Further, the isoallelic invasive strain with the carrier sclA allele persisted in the mouse nasopharynx and had increased adherence to cultured epithelial cells. Repair of the premature stop codon in the invasive sclA allele restored the ability to bind the extracellular matrix proteins laminin and cellular fibronectin. These data demonstrate that a mutation in GAS carrier strains increases adherence and decreases virulence and suggest selection against increased adherence in GAS invasive isolates.

Prevalence of group A streptococcal pharyngitis among schoolchildren of Barabanki district, Uttar Pradesh, India

Background: The aim of this study was to determine the prevalence of Group A streptococcus (GAS) pharyngitis and its carriage among schoolchildren in the age group 5-15 years in Barabanki district, Uttar Pradesh, India. The study also aimed to determine the minimum inhibitory concentration (MIC) of Penicillin G, antimicrobial susceptibility pattern and inducible Clindamycin resistance in GAS. Materials and Methods: Three hundred schoolchildren from six different schools were included in the study. Identification of group A streptococcus was done on the basis of Bacitracin sensitivity test, pyrrolidonyl peptidase (PYRase) test and Lancefield grouping by latex agglutination test. Antibiotic susceptibility test and D-zone test were done in GAS isolates. Results: Out of the 300 schoolchildren, GAS was found in three (4.7%) out of 63 symptomatic children and two (0.8%) out of 237 asymptomatic children. The overall prevalence of GAS pharyngitis and of GAS carriage was 1% and 0.67%, respectively. The isolation of GAS was significantly higher in symptomatic cases when compared to asymptomatic cases (P value = 0.0308). All the strains were sensitive to Penicillin, Ampicillin, Quinupristin-Dalfopristin, Vancomycin and Linezolid. Conclusion: A low prevalence of GAS pharyngitis and GAS carriage was observed in the study, probably due to the cross-sectional nature of the study. All five GAS isolates were sensitive to Penicillin.

Investigation of a Prolonged Group A Streptococcal Outbreak Among Residents of a Skilled Nursing Facility, Georgia, 2009-2012

Group A Streptococcus (GAS) is an important bacterial cause of life-threatening illness among the elderly. Public health officials investigated a protracted GAS outbreak in a skilled nursing facility in Georgia housing patients requiring 24-hour nursing or rehabilitation, to prevent additional cases. We defined a case as illness in a skilled nursing facility resident with onset after January 2009 with GAS isolated from a usually sterile (invasive) or nonsterile site (noninvasive). Cases were "recurrent" if >1 month elapsed between episodes. We evaluated infection control practices, performed a GAS carriage study, emm-typed available GAS isolates, and conducted a case-control study of risk factors for infection. Three investigations, spanning 36 months, identified 19 residents with a total of 24 GAS infections: 15 invasive (3 recurrent) and 9 noninvasive (2 recurrent) episodes. All invasive cases required hospitalization; 4 patients died. Seven residents were GAS carriers. All invasive cases and resident carrier isolates were type emm 11.0. We observed hand hygiene lapses, inadequate infection documentation, and more frequent wound care staff turnover on wing A versus wing B. Risk factors associated with infection in multivariable analysis included living on wing A (odds ratio [OR], 3.4; 95% confidence interval [CI], .9-16.4) and having an indwelling line (OR, 5.6; 95% CI, 1.2-36.4). Cases ceased following facility-wide chemoprophylaxis in July 2012. Staff turnover, compromised skin integrity in residents, a suboptimal infection control program, and lack of awareness of infections likely contributed to continued GAS transmission. In widespread, prolonged GAS outbreaks in skilled nursing facilities, facility-wide chemoprophylaxis may be necessary to prevent sustained person-to-person transmission.