Fear, Access, and the Real-Time Estimation of Etiological Parameters for Outbreaks of Novel Pathogens

Nina H Fefferman; Eric Lofgren; Nianpeng Li; Pieter Blue; David Weber; Abdul-Aziz Yakubu

) (t i a , and ) (t r a are the fractions of the populations 143 in the respective health categories at time t. To build the perceived disease process from 144 this model, we then incorporate rates of testing for each fraction of the population, and 145 the sensitivity and specificity of the test as follows. 146 147 Importantly, we will define as susceptible any person one who is not infected with our the 148 pathogen of concern, despite possible infection with another illness. It is therefore not 149 only reasonable but probable that "susceptible people" will seek out health care services 150 and be tested for infection under our surveillance process, especially if the symptoms of 151 their infection closely match those of the pathogen causing our focal outbreak. We 152 therefore define α to be the rate at which susceptible people are tested for illness, call δ 153 the rate at which infected people are tested for illness, and call λ the rate at which 154 recovered people are tested for illness. (For purposes of this paper, we will assume 155 λ α = , however this assumption may be relaxed in future work if memory of recently 156 resolved symptoms affects health care seeking behavior). We define the false positive 157 rate of the diagnostic test 1 ε and the false negative rate of the test 2 ε (these may apply 158 either to clinical diagnostic sensitivity and specificity, or else to error rates stemming 159 from differences in physician opinion during syndromic surveillance). 160 161 . CC-BY-NC-ND 4.0 International license It is made available under a author/funder, who has granted medRxiv a license to display the preprint in perpetuity.