{
  "abstract": "Introduction Autoimmune neuropsychiatric disorders related to ‘strep throat’ (infection of upper respiratory tract caused by streptococcus pyogenes) in children have been described for over 25 years. The most common neuropsychiatric symptoms described are those resembling OCD and Tic disorder but often include anxiety and food restriction. Existing clinical studies have demonstrated conflicting and limited evidence of the relationship between streptococcus infection and neuropsychiatric outcomes. Therefore, we aimed to explore the neuropsychiatric effects of streptococcus pyogenes throat infection hypothesis using a largescale healthcare database in the context of a recent respiratory illness in a large paediatric population.Methods The analysis was run using TriNetX, a global federated health research network providing access to electronic medical records. The primary cohort was defined as those with a confirmed diagnosis of any Acute upper respiratory infection (ICD 10- J00-J06) followed by a positive Streptococcus pyogenes test within 2 weeks which occurred between the ages of 3 and 16. The control cohort had a confirmed negative Streptococcus pyogenes test within 2 weeks after any Acute upper respiratory infection.We compared the incidence of five outcomes (Any mental disorder, Tic disorder, restricted oral intake, anxiety and obsessive-compulsive disorder) between both groups using risk ratios which occurred up to one year following their test result. Participants were propensity matched on 71 baseline variables using a 1:1 greedy nearest neighbour algorithm.Results Our Primary cohort included 487,872 patients and comparison cohort included 1,032,465 patients prior to matching. After matching there were 467,413 patients in both groups. Both prior to and after matching for covariates, a positive Streptococcus test compared to a negative test was associated with a reduced risk of any mental disorder, restricted oral intake and anxiety disorder. The risk of developing OCD was lower in the positive streptococcus group prior to matching [0.81 (0.72, 0.91)] but was no longer significant after matching [0.95 (0.83, 1.08)]. Tic disorder was not significantly different before [RR 1.05 (0.97, 1.13)] or after matching.Discussion This large-scale retrospective paediatric cohort study demonstrated no increase in risk of any neuropsychiatric outcomes after a positive streptococcus test following a recent upper respiratory tract infection. In fact, after matching a positive streptococcus antigen test was associated with slightly lower risk of food restriction, anxiety disorder and any recorded mental disorder. Therefore, we were not able to find any evidence supporting that specific exposure to streptococcus pyogenes is related to increased autoimmune neuropsychiatric outcomes.",
  "authors": [
    {
      "affiliations": [
        "Department of Psychosis Studies, Institute of Psychiatry Psychology and Neuroscience, King’s College London, UK",
        "*First and presenting author"
      ],
      "name": "Danish Hafeez"
    },
    {
      "affiliations": [
        "Department of Psychosis Studies, Institute of Psychiatry Psychology and Neuroscience, King’s College London, UK"
      ],
      "name": "Katharine Lynch-Kelly"
    },
    {
      "affiliations": [
        "Department of Psychosis Studies, Institute of Psychiatry Psychology and Neuroscience, King’s College London, UK"
      ],
      "name": "Thomas Pollak"
    }
  ],
  "title": "Psychiatric outcomes of paediatric exposure to streptococcus pyogenes in the context of respiratory infections- a retrospective cohort study",
  "uid": "2c0203d9-1e2e-5616-a138-4208bdca6838"
}