Chlamydial infections
Chlamydophila abortus : Human
infection
In the literature, there are several reports of human abortion, or severe respiratory disease in non-pregnant humans, derived from chlamydiae from aborting sheep
(Mare, 1994). These reports stem from the 1950s
(Giroud and Jadin, 1954) to the present
(Jorgensen, 1997). The majority of these reports are of abortions in pregnant sheep farmer’s wives, exposed to chlamydiae mainly during lambing. In one case, the affected person died suddenly during spontaneous labour, and the infant died 2 hours after birth. A pregnant sheep farmer’s wife, who avoided contact with a flock in which abortion had not taken place for 1 year, still acquired infection and aborted.
Other occupations that have come into contact with chlamydiae from aborting sheep and developed disease include abattoir workers, vaccine manufacturing workers, and laboratory scientists.
It is clear that persons associated with sheep should be made aware of the dangers of infection. During lambing,
particularly if abortions are occurring, protective clothing (including boots and gloves) should be worn.
Additionally, disinfection of potentially infected areas and materials should be carried out. Pregnant women should stay away from sheep, especially during lambing.
Inhalation of infected material from sheep can also result in chlamydial respiratory disease in non-pregnant humans.
However, in general, the products of the sheep dairy industry are not a hazard to human health.
Human infection resulting from contact with infected goats has
also been reported (Villemonteix et al.,
1990; Popischil et al.,
2002). The latter paper describes an "abortion storm" on a Swiss farm with
cattle and goats, which affected 50% of the goats during the lambing season. In
one of three investigated caprine abortions Chlamydophila abortus was
identified as the cause. However during this time a woman in the 19/20th week of
pregnancy and who had contact with aborting goats developed a severe generalized
infection and herself aborted. Her placenta contained Chlamydophila abortus
as shown by both immunohistochemistry and PCR. It is clear therefore that
aborting goats as well as aborting sheep are a potential hazard to pregnant
women [Popischil et al., 2002].
Human infection can also be acquired from cattle.
The evidence for this is indirect, being primarily based on the presence
of complement fixing antibodies (Enright and Sadler,
1954).
The most compelling evidence is a case of fatal pneumonitis in a cattle rancher
in the USA (Barnes and Brainerd, 1964). In the human patient, a persistent febrile state was observed despite a prolonged course of tetracycline. Mild dry cough, dyspnoea and malaise were early signs that preceded the development of acute pneumonitis,
followed by severe tachypnoea and extreme
cyanosis . Chlamydiae were isolated from cardiac blood. Lesions in the lung resembled those seen in the
pneumonitis associated with
avian-derived C. psittaci infection in humans. In this particular case, the rancher had handled aborted foetuses from
a herd which had experienced high levels of abortion for several years. Chlamydial infection
was implicated in the bovine abortion episodes. Three other people on the ranch also developed measurable antibody responses to chlamydiae.
Bovine chlamydial infection has also been implicated in a case of human abortion
(Page and Smith, 1974).
It would be wise to treat cases of bovine abortion with the same caution as
those in sheep. At any time during the year but particularly the calving season
or if abortions are occurring, humans exposed to cattle should be vigilant for the development of mild to severe febrile
disease and aware of the possibility of chlamydial infection from bovine
sources.
[PG Updated MEW June 2003]
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