Pharyngitis Complications in North America in the 21 st Century

Transcription

1 CUMMING SCHOOL OF MEDICINE Department of Family Medicine Pharyngitis Complications in North America in the 21 st Century Do current guidelines lead to overdiagnosis and overtreatment Dr. Ian Johnston MBChB, BSc (Hons) Dr. James Dickinson, Dr. Carmen Gittens 1 st September 2015

2 Conflicts of Interest None to disclose

3 Background Acute Rheumatic Fever (ARF) Immunologic sequelae Group A streptococcus (GAS) infection Can lead to Rheumatic Heart Disease (RHD). ARF links to GAS pharyngitis established 1950s. Warren Air Force Base (Southern Wyoming). Studies supported antibiotic prescription to reduce incidence of ARF. Conclusions largely supported by recent Cochrane reviews. Two thirds reduction in chance of ARF with primary antibiotics. o Where this complication is common.

4 Background Cochrane database Syst Rev. 2013;11(11). doi: / cd pub4.

5 Background ARF already declining before penicillin. Improvements in hygiene and overcrowding. ARF and RHD still a significant cause of morbidity. Developing world Aboriginal communities in Australia/New Zealand.

6 U.S. CDC made ARF not notifiable Incidence <1 per million. Isolated reports since. e.g. Utah late 90s. Canadian Pediatric Surveillance Program ( ) 2.9 per million (<18 population) Other western countries incidence very low. Guidelines worldwide: Swab & treat for GAS to prevent non-suppurative (ARF) and suppurative complications. Background

7 Objectives Current rate in Canada? Relationship to aboriginality and crowding?

8 Methods Retrospective study of routinely collected data. Canadian Institute for Health Information (CIHI) admission data (ICD10-CA codes) from 2004/5-2010/11 with a most responsible or secondary diagnosis of ARF including: I00 - Rheumatic fever without mention of heart involvement I01 - Rheumatic fever with heart involvement I02 - Rheumatic chorea Includes all discharges from acute inpatient care across Canada with an age <18 (excludes Quebec). Canadian census data Aboriginal population by health region. Crowded dwellings >1 person/room.

9 Results 275 cases identified - 7 year study period 5.58/million under 18 population (7.04 million). 6% of under 18s live in predominantly aboriginal communities.

10 Results Percetange Aborignal Proportion Crowding

11 Results Burntwood, MB Hospitalisation rate per million < Mamawetan Churchill River, SK Keewatin Yatthu, SK Percentage Aboriginal Population

12 Results Burntwood, MB Hospitalisation rate per million < Keewatin Yatthu, SK Mamawetan Churchill River, SK Proportion Crowding

13 Results ARF Hospitalization Rate (per year, per 1,000,000 persons <18y) Quebec (Regional data not available) Burntwood Rate: Quebec Regional data not available Keewatin Yatthe Rate: Mamawetan Churchill River Rate: 70.48

14 Results Likely overestimation: Data is individual hospitalizations. Each child admitted locally, then transferred for specialist assessment/echo etc. Each case appears in data twice. Any recurrence in the 7 year period will be admitted again (also twice).

15 Discussion Common Belief Evidence Need to have a sore throat to get ARF. 80% of cases of ARF no recollection of antecedent throat infection. Every GAS sore throat may cause ARF. Repeated infections to trigger first episode of ARF. Not all Group A strep strains rheumatogenic. Every case of ARF will get RHD. 40% of cases of RHD no recognized history of ARF. Repeated ARF necessary to progress to RHD. Oral antibiotics needed to prevent RHD Secondary prophylaxis with IM penicillin following ARF most cost effective way to prevent RHD.

16 Discussion Lancet. 2012;379(9819): doi: /s (11)

17 Discussion Antibiotics/otitis media. 1 in 14 children treated with antibiotics = adverse event (vomiting/diarrhea/rash) Cochrane Database Syst Rev. 2013;(1). doi: / cd pub2. International collaborative study of severe anaphylaxis. Oral antibiotics = Low risk (5-15/ exposed patients). Pharmacoepidemiol Drug Saf. 2003;12(3): doi: /pds.822. Scottish study NNT of > J R Coll Gen Pract. 1985;35(274): >7000 additional cases vomiting/diarrhea/rash 5-15 Anaphylactic/anaphylactoid reactions.

18 Discussion 7.3 Million pediatric sore throats annually (US data). Antibiotics 53%. Not recommended ones 27% (increased resistance). J Am Med Assoc. 2005;294(18): doi: /jama ~95% pharyngitis viral. 20% of children asymptomatic chronic carriers of GAS. Can Fam Physician. 2011;57(7): Clin Infect Dis. 2012;55(10): doi: /cid/cis629 Clinical prediction rules don t help decide who to swab. Can Med Assoc J. 2014;187(1): doi:doi: /cmaj

19 Further Work CIHI currently re-running the numbers up to 2014 Including suppurative complications of GAS J36 Peritonsillar abscess J39.0 Retropharyngeal and parapharyngeal abscess Watch this space

20 Conclusion ARF rare in western countries. Other complications rare/easily managed. Further supportive data anticipated Antibiotics unacceptable risk of harm. Consider antibiotics in high risk. ~6% Canadian kids. Secondary antibiotics in remainder. ~94% Canadian kids. Guidelines need to change to reflect this.

21 Try not to see a wolf when it s not there! Questions Acknowledgements: Dr. Gittens and Dr. Dickinson for the initial work, help and support with project. Grace Perez for statistical support. Analysts at CIHI for data support. Photograph of Peyto Lake, Banff national park AB - Courtesy Breanna Uzelman ian.johnston2@ucalgary.ca