F2F Poster 21st Lancefield International Symposium for Streptococci and Streptococcal Diseases 2022

Throat as portal of entry in invasive Group A Streptococcal disease: a prospective 2-year study in two health districts, Finland (#317)

Ville Kaila 1 , Johanna Vilhonen 2 , Kirsi Gröndahl-Yli-Hannuksela 3 , Kaisu Rantakokko-Jalava 4 , Tapio Seiskari 5 , Kari Auranen 6 , Emilia Lönnqvist 3 , Mirva Virolainen 3 , Hanne-Leena Hyyryläinen 7 , Jarmo Oksi 2 , Jaana Syrjänen 1 , Jaana Vuopio 3
  1. Department of Internal Medicine, Infectious Disease Unit, Tampere University Hospital, Tampere, Finland
  2. Infectious Diseases, Turku University Hospital, Turku, Southwest Finland, Finland
  3. Institute of Biomedicine, University of Turku, Turku, Finland
  4. Clinical Microbiology, Turku University Hospital, Turku, Finland
  5. Clinical Microbiology, Tampere University Hospital, Tampere, Finland
  6. Department of Mathematics and Statistics, University of Turku, Turku, Finland
  7. Finnish Institute for Health and Welfare, Helsinki, Finland

Background

Streptococcus pyogenes (Group A Streptococcus, GAS) is an important human pathogen, that may colonize the mucous membranes, but can also cause severe invasive (iGAS) infections. Often the portal of entry cannot be located. It has been assumed that hematogenous seeding from the nasopharynx may occur. In this study we aimed to test this hypothesis of throat being a possible portal of entry in an iGAS infection.

Methods

We performed a prospective clinical study covering iGAS infections in two university hospitals in Finland. All recruited patients were interviewed to gather information on possible preceding tonsillitis-like symptoms and a throat swab was taken for culture and isothermal amplification tests (IAT) to search for GAS.

Results

Altogether 45 patients were enrolled. Ten patients (22%) had a positive IAT. In the interview, 14 patients of 37 (38%) reported having had a sore throat prior to the onset of other symptoms. Information on throat soreness was not available in eight patients. The 20 patients with preceding throat soreness and/or positive IAT were significantly younger (45.3 vs. 60.7 yr., p=0.010), were more likely to have a body mass index (BMI) less than 30 kg/m2(p=0.005), had a lower Charlson class (p=0.033), but needed invasive mechanical ventilation more often (p=0.018) than the 22 patients without sore throat or positive IAT.

Conclusions

Prior throat soreness or GAS throat colonization was frequently observed among patients with iGAS infection. Hematogenous seeding from the nasopharynx may be an important portal of entry especially among younger and healthier patients with severe disease.