PhD thesis - University of Hertfordshire Research Archive

papers (Pearson et al., 1977; Bruce, Zochowski, & Ferguson, 1977; Blaser &
Reller, 1981; Norkrans & Svedhem, 1982; Kist, 1982; Severin, 1982; Taylor
et al., 1983; Hopkins & Scott, 1983; Blaser, Taylor, & Feldman, 1983;
Santosham et al., 1983; Potter et al., 1983; Kist, 1983; Oosterom et al., 1983;
Hopkins, Olmsted, & Istre, 1984; Oosterom et al., 1984; Engleberg et al.,
1984; Nolan, Harris, & Canova, 1984; Hopkins & Olmsted, 1985; Kist &
Rossner, 1985b; Harris, Weiss, & Nolan, 1986; Harris et al., 1986; Harris,
Weiss, & Thompson, 1986; Salfield & Pugh, 1987; Schmid et al., 1987; Harris
et al., 1987; Saeed, Harris, & DiGiacomo, 1993; Kassenborg et al., 2004).
Further scrutiny revealed eight were not case-control studies (Pearson et al.,
1977; Bruce, Zochowski, & Ferguson, 1977; Norkrans & Svedhem, 1982;
Hopkins & Olmsted, 1985; Hudson et al., 1990; Svenungsson et al., 2000;
Engberg et al., 2004; Olesen et al., 2005), four were case-case comparisons
(Murray, 1986; Neal & Slack, 1995; Evans, Ribeiro, & Salmon, 2003;
Kassenborg et al., 2004), three were non-exposure case-control studies
(Neal et al., 1996; Smith et al., 2002; Ethelberg et al., 2005), three provided
insufficient detail (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 onto peer-reviewed
publications which were included already (Oosterom et al., 1983; Nolan,
Harris, & Canova, 1984) and one focussed on protective factors for
Campylobacter infection (Cameron et al., 2004). One manuscript (Harris,
Weiss, & Thompson, 1986) cited in the reference list of 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.
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 1).
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