PhD thesis - University of Hertfordshire Research Archive

susceptibility to Campylobacter infection (Neal, Scott, Slack, & Logan, 1996),
one examined the impact of Campylobacter infection on health and health-
related behaviour (Smith et al., 2002), and one examined demographic and
geographic parameters in relation to Campylobacter infection (Ethelberg et
al.. 2005), three described case-control studies in detail too scant to
contribute meaningfully to understanding (Santosham et al., 1983; Kist 1983;
Baker et al., 2005), two were review articles (Blaser & Reller, 1981; Blaser,
Taylor, & Feldman, 1983), two described outbreaks of Campylobacter
infection (Potter et al., 1983; Harris et al., 1987), two were reports which went
on to peer-reviewed publications already included (Oosterom et al., 1983;
Nolan, Harris, & Canova, 1984) and one focussed on factors which reduce
the risk of Campylobacter infection (Cameron, et al., 2004). One manuscript
(Harris, Weiss, & Thompson, 1986) cited in another (Saeed, Harris, &
DiGiacomo, 1993) did not exist. These papers were excluded, and three
papers (Harris, Weiss, & Nolan, 1986; Harris et al., 1986; Saeed, Harris, &
DiGiacomo, 1993) reporting different aspects of the same study were
combined into a single record, leaving 35 studies for analysis.
Twelve studies were published in the 1980s, ten in the 1990s and thirteen to
date this decade, with most studies conducted in North America, the United
Kingdom (UK) and the rest of Europe in each of these decades respectively
(table A3.1). Studies were most frequently conducted over twelve months on
subjects from all age groups, but some were restricted to adults or
infants/children. The average number of study participants increased over the
surveillance period, with the number of parameters under investigation
increasing commensurately. Studies increasingly focused on indigenously-
acquired infections, employed matching in control selection and utilised
multivariate statistical techniques in analysis. Surprisingly, the period of
exposure for which information was sought did not vary greatly, averaging
nine days.
Based on the information reported, most studies asked participants about
recent exposure to poultry (especially chicken) or dairy produce, as well as
foreign travel and contact with animals and the wider environment. A
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