In the article that appeared on pages e1–e11 of volume 22, issue 2, the formula of the skim-milk tryptone glucose glycerol (STGG) transport medium as listed on page e5 incorrectly references the units as ml for the quantity of tryptone-soya broth. The proper formulation should have been noted as 3.0 g of Oxoid tryptone-soya broth, relative to the quantities of the other ingredients in the STGG medium as is described in the original citation for the transport medium (Gibson LT, Khoury JT. Storage and survival of bacteria by ultra-freeze. Lett Appl Microbiol. 1986;3:127–129).
O'Brien KL, Nohynek H, and the WHO Pneumococcal Vaccine Trials Carriage Working Group. Report from a WHO Working Group: standard method for detecting upper respiratory carriage of Streptococcus pneumoniae. Pediatr Infect Dis J.