Table 1.

Baseline Frequencies of Respiratory Cases Observed in Year 1, Disease Detection Thresholds and Retrospective Respiratory Cluster Detection for Years 2005–2012. Prevalence Describes the Proportion of Chimpanzees with Respiratory Signs Among the Individuals Observed Within the Week. Community Thresholds Were Set so that Approximately 95% of Baseline Data Fell Within the Threshold Level. Thresholds Were Used to Detect Clusters of Respiratory Cases that Significantly Exceeded Year 1 Baseline Levels in Daily Health Record (DHR) Data from March 2005 to December 2012. For Each Detection, DHR and Weekly Health Record (WHR) Data Were Examined to Estimate the Cluster Size (i.e., Number of Cases) and Rule out False Alarms (i.e., a Signaled Event with < 2 Cases).

	Kasekela	Mitumba
Year 1 baseline weekly number of cases, mean (range)	0.2 (0–2)	0.35 (0–3)
Count threshold	≥ 2	≥ 2
Number of weeks with detections	12	9
Number of respiratory clusters	8	5
Range of cluster sizes	2–55	2–24
Year 1 baseline weekly prevalence of cases, mean (range)	2.7% (0–28.6%)	8.2% (0–50%)
Prevalence threshold	≥ 16.7%	≥ 33.3%
Number of weeks with detections	10	8
Number of respiratory clusters	5	4
Range of cluster sizes	6–55	3–24