Table 1 Thresholds for the definition of sleeping sickness risk categories. Thresholds are applied to the risk function R (i.e., the ratio between the average annual intensity of HAT cases and the intensity of exposed population). Where the risk function is < 10−6 (i.e., < 1 HAT case per 106 people per annum), risk is considered ‘marginal’ [17]
From: Human African trypanosomiasis in the Democratic Republic of the Congo: disease distribution and risk
Category of risk | R | HAT cases per annum |
|---|---|---|
Very high | >10−2 | ≥1 per 102 people |
High | 10−3 < R < 10−2 | ≥1 per 103 people AND < 1 per 102 people |
Moderate | 10−4 < R < 10−3 | ≥1 per 104 people AND < 1 per 103 people |
Low | 10−5 < R < 10−4 | ≥1 per 105 people AND < 1 per 104 people |
Very low | 10−6 < R < 10−5 | ≥1 per 106 people AND < 1 per 105 people |