[1] Imperial Coll, Dept Surg & Canc, St Marys Hosp Campus, London W2 1PG, England
[2] Imperial Coll, Div Med, St Marys Hosp Campus, London W2 1PG, England
[3] Imperial Coll, Dept Infect Dis, St Marys Hosp Campus, London W2 1PG, England
[4] Imperial Coll Healthcare NHS Trust, Jefferiss Wing, Dept HIV Med, St Marys Hosp, London W2 1NY, England