Previous
Next

Index
 several weeks before these reports there had been a break in a major sewer line in the area and there had been reports of persons with raw sewage in their yards. There was also the possibility of contamination of potable water supplies. Hepatitis A investigations are especially difficult because of the long incubation period. Questions are often phrased as ”where do you usually purchase …” rather than going for specifics. The technique used in this type of interview is quite
    different from that used for research purposes. In a research interview, questions are preset and the goal is consistency with the aim of reducing variability. In investigative interviews, the purpose is to pick up “leads”. While there are a basic set of points to be covered (child care and restaurant exposures, IV drug use, etc), responses drive the interview. Names of specific establishments are not used in order to avoid biasing respondents. Once the public is aware of a problem with a particular establishment, the effectiveness of interviewing is significantly compromised. It was difficult to maintain a neutral voice tone and confine comments to a calm “Uh huh” when the sixth person has just told you they shopped at the same store as the other five persons.

    The occurrence of the sewer break threw a real wrench into this investigation as we now had 2 possible sources to contend with. Although we had 9 persons who shopped at the same market, this was one of the largest in the area and it was quite possible that this reflected shopping patterns of area residents rather than the source of infection. We needed a comparison group. We could have used neighbor controls but the hour was late and we didn’t want to raise public awareness until and unless it was unecessary.

Slide 16 of 25