hostklion.blogg.se - Retrospective cohort study

Conduct a small number of in-depth, open-ended interviews.Be mindful that new sources frequently occur, given ever-changing social, behavioral, and commercial trends. Consult health department records, review the literature, and consult experts to learn about previous sources. Determine sources of similar outbreaks.Interviews with these patients can yield important clues (e.g., by identifying the index case, secondary case, or a narrowed list of common exposures). Give extra attention to the earliest and latest cases on an epidemic curve and to persons who recently visited the neighborhood where the outbreak is occurring.

Further investigation of the parenteral nutrition administered to adults but not children in that hospital identified contaminated amino acid solution as the source ( 1).

In an outbreak of bloodstream infections caused by Serratia marcescens among patients receiving parenteral nutrition (food administered through an intravenous catheter), investigators had a difficult time finding the source until they noted that none of the 19 cases were among children.

(Of course, generalizations do not always hold true!)

By examining the sex distribution among persons in outbreaks, US enteric disease investigators have learned to suspect a vegetable as the source when most patients are women.

Descriptive epidemiology (see Chapter 6) can help develop hypotheses. The initial steps of an investigation, described in previous chapters, are some of your best sources of hypotheses. Example: Using an Analytic Study to Solve an Outbreak at a Church Potluck Dinner (But Not That Church Potluck).Selection of Controls in Case–Control Studies.Types of Observational Studies for Testing Hypotheses.