Researchers in Canada are beginning to answer an important question raised by the recent, rapid rise in invasive group A Streptococcus (GAS) infections: how to assess risk of infection among close contacts of patients.
The researchers found that the length of time spent with an infected person was a key factor in determining who became a GAS carrier. From March 1995 to March 1996, they studied 102 contacts of 17 patients treated for invasive GAS at Hôpital Maisonneuve-Rosemont in Montreal. The contacts were split into two groups: those who had spent 24 hours or more with a patient during the week before symptoms began and those who had spent 12 to 24 hours with a patient during that period. All the contacts received throat cultures when patients were hospitalized and again 2 weeks later.
Voelker R. Timing Key in Group A Strep. JAMA. 1999;281(22):2078. doi:10.1001/jama.281.22.2078