Author + information
- Louise Eske Bruun,
- Mia Nielsen,
- Robert Skov,
- Thomas Gerds,
- Per Kragh,
- Gunnar Gislason and
- Christian Torp–Pedersen
Staphylococcus aureus is a major cause of Infective Endocarditis (IE). A genetic predisposition to Staphylococcus aureus bacteraemia (SAB) has been demonstrated in mice and we therefore we examined if a family history of SAB in first–degree relatives increases the risk of SAB and whether the risk changes with gender of the first–degree relatives.
We used nationwide registers to identify citizens with a first episode of SAB (index–cases) admitted to hospital in the years 1991–2012 and to trace their first–degree relatives (study–cases). Poisson regression was used to determine rate ratios (RRs) of SAB using the incidence in the general population as a reference. Sensitivity analyses were performed to take contagiousness bias into account, by excluding the study–cases diagnosed with SAB <1 year after the index–cases acquired SAB.
From 1991–2012, 23.607 patients were diagnosed with SAB. For the entire Danish population we identified 10.623 offspring's to 5214 maternal index–cases, 18.392 offspring's to 8346 paternal index–cases and 7412 siblings to 4825 index–cases of siblings. Study–cases (children/siblings) had a mean follow up time of 2.5 years (IQR: 1.25–3.75). In total, 64 study–cases acquired SAB during the study period. The RR of incurring SAB was 2.10 (95% CI (CI) 1.65–2.68) in subjects having a first–degree relative previously admitted with SAB. RRs were 1.7 (CI 1.00–2.84) and 2.2 (CI 1.65–2.91) having a sibling or a parent admitted with SAB, respectively, as compared to the general population. A paternal or maternal index–case >50 years was associated with RRs of 2.03 (CI 1.37–3.00) and 1.79 (CI 1.04–3.09), respectively. No significant results were observed for parents ≤ 50 years. Siblings to a male index case had a RR of 2.4 (CI 1.43–3.92), whereas no significant risk was observed in siblings to a female index case (RR 1.2, CI 0.74–3.31). However, no interaction with gender was found, neither in parents (p=0.80) nor in the sibships (p=0.14). The sensitivity analysis resulted in significant RRs slightly different from the primary RRs.
For the first time a significant familial clustering of SAB has been demonstrated.
Poster Sessions, Expo North
Sunday, March 10, 2013, 9:45 a.m.–10:30 a.m.
Session Title: Valvular Heart Disease: Clinical V – Endocarditis
Abstract Category: 31. Valvular Heart Disease: Clinical
Presentation Number: 1198–88
- 2013 American College of Cardiology Foundation