High burden of invasive group A streptococcal disease in the Northern Territory of Australia

Abstract

Although the incidence of invasive group A streptococcal disease in northern Australia is very high, little is known of the regional epidemiology and molecular characteristics. We conducted a case series of Northern Territory residents reported between 2011 and 2013 with Streptococcus pyogenes isolates from a normally sterile site. Of the 128 reported episodes, the incidence was disproportionately high in the Indigenous population at 69·7/100 000 compared to 8·8/100 000 in the non-Indigenous population. Novel to the Northern Territory is the extremely high incidence in haemodialysis patients of 2205·9/100 000 population; and for whom targeted infection control measures could prevent transmission. The incidences in the tropical north and semi-arid Central Australian regions were similar. Case fatality was 8% (10/128) and streptococcal toxic shock syndrome occurred in 14 (11%) episodes. Molecular typing of 82 isolates identified 28 emm types, of which 63 (77%) were represented by four emm clusters. Typing confirmed transmission between infant twins. While the diverse range of emm types presents a challenge for effective coverage by vaccine formulations, the limited number of emm clusters raises optimism should cluster-specific cross-protection prove efficacious. Further studies are required to determine effectiveness of chemoprophylaxis for contacts and to inform public health response.

High Incidence of Invasive Group A Streptococcal Infections in Remote Indigenous Communities in Northwestern Ontario, Canada

“…In contrast, the crude incidence rate of iGAS calculated in this study among 26 rural and remote First Nations communities in Northwestern Ontario between 2009 and 2014 was more than 10 times higher at a rate of 56.2 per 100 000 population. Although significantly higher than the incidence of iGAS among indigenous peoples in Northern Canada (2.25–20.44 per 100 000 population) [2], it is comparable to indigenous populations in Australia and New Zealand [3, 4, 14, 15]. …”

“…It has been hypothesized in Northern Australia that a major risk factor for GAS bacteremia in Aboriginal people is exposure to an overall high burden of GAS infections, primarily skin infections such as impetigo and pyoderma [3, 26]. These populations also experience high prevalence of nonsuppurative sequelae to GAS infection including acute rheumatic fever and poststreptococcal glomerulonephritis [27, 28].…”

The Nasal and Oropharyngeal Microbiomes of Healthy Livestock Workers

“…Due to its high prevalence in livestock workers, it may be a potential cause of difficult-to-diagnose infections in people with livestock contact, especially in the immunocompromised [34]; however, little information on Dietzia as an opportunistic pathogen exists. Other potential pathogens found in higher abundance in livestock workers were Prevotella [35–37], Streptococcus [38–40], Moraxella [41, 42], Rothia [43], and Oscillibacter [44].…”

Impetigo and scabies – Disease burden and modern treatment strategies

“…S. pyogenes bacteraemia and streptococcal toxic shock syndrome are commonly preceded by skin and soft tissue infection. 11,12 S. aureus bacteraemia carries a high mortality and skin infection is an important risk factor in settings where impetigo is common. 8,13 Where S. pyogenes is the predominant pathogen, impetigo can also lead to significant immune-mediated complications.…”

“…27,38,39 Recommendations for the use of chemoprophylaxis to decolonise household contacts of cases of invasive S. pyogenes disease vary and clear evidence of efficacy in preventing invasive disease is lacking. 12,40 The role of broader community based S. pyogenes decolonisation in the prevention of skin disease has not been assessed.…”