Coconino County Health Department exploring a currently unknown communicable disease (illness that is spread from one person to another, from an animal to a person, or from a surface or a food), called Disease X

Below are data that you collected for an internship with the Coconino County Health Department exploring a currently unknown communicable disease (illness that is spread from one person to another, from an animal to a person, or from a surface or a food), called Disease X. You have a hypothesis that a contaminant from PurinalE) dog food may cause Disease X. You recruit 10 individuals who worked at the Flagstaff Nestle Purina® Plant and 10 Flagstaff residents that did n_ot work at the plant to participate in your study. You tested all participants for Disease X every morning for 10 days. Individuals were followed until they withdrew from the study, they got Disease X, or the end of the study. All 20 individuals were free of Disease X at the start of the study. Note: once a participant got Disease X, they were no longer able to get Disease X again. “P NESTLE PURINA® PLANT WORKERS . . . . Developed Disease Participant Follow Up Time (In days) 1 3 Y 2 10 10 73 oerson da s _’ _. _. FLAGSTAFF RESIDENTS THAT DO NOT WORK AT THE PURINA® PLANT Developed Disease Partlcmant x Yes or No Follow-Up Time (in days) 10 10 10 10 10 10 84 oerson da s

a. What is the study design? b. Is your study population dynamic or fixed? Explain your answer. c. What is the prevalence of Disease X at baseline among all participants? d. What is the cumulative incidence (risk) of Disease X over the 10-day study among all participants? e. What is the cumulative incidence (risk) of Disease X over the 10-day study for Purina® plant workers? f. What is the cumulative incidence (risk) of Disease X over the 10-day study among non-plant workers? g. Calculate the risk ratio of Disease X comparing Purina® plant workers and non-plant workers. Interpret in a sentence. h. What is the incidence rate of Disease X during the study period among Purina® plant workers? i. What is the incidence rate of Disease X during the study period among non-plant workers? j. Calculate the rate ratio comparing Purina® plant workers and non-plant workers. Interpret in a sentence. k. What is your conclusion based on these results? Was your hypothesis correct?