Timeliness of Salmonella notifications in South Australia

To evaluate the timeliness of Salmonella serotype and phage type notifications in South Australia.

We surveyed all notifications of Salmonella to the South Australian Department of Human Services between July 1995 and June 1996. We entered data onto an Epi Info 6.02 database and calculated the time interval between various stages of typing notification.

The median time taken between collection of a faecal specimen and receipt of serotype notification was 10 days (range, 5-38), while phage type notification took a further seven days (range 0-40). The time interval between collection of a specimen and notification of a Salmonella final identity was 14 days (range 6-49). The internal mail system of the Department of Human Services delayed notification a median of two days. Environmental Health Officers supplied reports for 224 (58%) of 384 cases, 71% of which occurred before the final Salmonella isolate was known.

We found that the internal departmental mail system delayed the notification of Salmonella. In South Australia, investigations should focus on clusters of cases of known Salmonella identity, rather than all notified cases.

To improve communicable disease investigations, health agencies should evaluate the timeliness of surveillance systems and examine the feasibility of transferring laboratory data electronically.