Cost Analysis of Investigations by a Local Health Department in Response to Cases of Pertussis

Background:
The number of reported Pertussis cases is increasing since the 1980's in the U.S. Case investigations for Pertussis are completed by local health departments (LHDs) for the purposes of confirmation and prophylaxis of close contacts. The cost of such activities incurred by a LHD represents another community cost associated with the disease burden of Pertussis which is underreported.

Objectives:
This study aims to characterize factors associated with the cost burden on a LHD while conducting case investigations of Pertussis.

Methods:
A total of 50 cases were randomly selected from the 542 cases reported to the LHD in 2004. Selected cases matched the characteristics of reported cases for 2004 according to average age, race, language spoken, and antimicrobial prophylaxis administration. Time requirements in order to conduct epidemiological case investigations and administration of antimicrobial prophylaxis were estimated from report documentation. Time estimates were multiplied by adjusted fixed costs to render an average cost of an investigation per case. Cases were grouped by covariates including whether the LHD provided prophylaxis directly, English vs. non-English speaking, and immunization status.

Results:
The mean cost per case was $211 ($35-$1,289) for the study set which equates to a total estimated cost to the LHD of $114,362 (95% C: $77,029-$151,695) for Pertussis cases in 2004. The average number of contacts identified per case was 5.6 (1-13). The average cost per case varied $321 vs $63 whether LHD administered antimicrobial prophylaxis directly or whether prophylaxis was given by another provider. Cost estimates did not differ according to immunization status or whether English was spoken.

Conclusions:
The costs incurred by Local and State Health Departments to investigate cases of Pertussis are substantial. This study further highlights the importance and benefit of Pertussis immunization by presenting another indirect cost burden incurred to the community when cases of Pertussis occur.