| Respiratory viruses cause significant morbidity and mortality. Institutions often contain populations at risk for severe complications, and crowding can drive transmission. This thesis presents methods for dealing with institutional outbreaks.;Detecting transmission depends on accurate and timely diagnostic and epidemiologic evidence. We developed techniques based on the incubation period that use the time of symptom onset to identify institutionally-acquired infections. We reviewed the literature on the incubation periods for: adenovirus, HCoV, SARS, influenza A and B, measles, parainfluenza, RSV and rhinovirus, identifying 38 documents with data for pooled analysis.;The estimated incubation periods ranged from 0.6 days for influenza B to 12.5 days for measles. For most respiratory viruses, ≥95% of cases will develop symptoms between 4/9 and 2 1/4 times the median; classifying those cases developing symptoms after being in the institution for 1.1 the median as having institutionally acquired infection will have 84% positive predictive value.;Respiratory virus detection by RT-PCR of mouthwash specimens would provide an easily administered test that could be widely deployed. We performed RT-PCR on mouthwash specimens collected from 36 patients and compared the results to those found by EIA and viral culture on conventional specimens (the gold-standard).;Of 29 gold-standard negatives, 29 tested negative by our test (100% specificity). Of 7 gold standard positives, 5 tested positive by our test (71% sensitivity).;Accurate measures of transmissibility and intervention effect are crucial in controlling outbreaks. We estimated the basic reproductive rate, R0, for an outbreak of a novel influenza in Fort Dix, New Jersey and four outbreaks of intra-pandemic influenza in Thailand. In the latter four we estimated how R changed over time and the effect of interventions.;In Fort Dix, transmission was confined to an army base, where R0 was 1.2. In the four Thai outbreaks, R 0 ranged from 2.6 to 5.9. Only in one outbreak was there an effective intervention, reducing transmission by 90%.;These institutional outbreaks highlight the challenge that rapid spread and increased transmission present to control. Only early detection will allow us to effectively intervene. The statistical and diagnostic methods presented here may make this possible. |
