ISRAEL JOURNAL OF
VETERINARY MEDICINE
INTESTINAL CHLAMYDIOSIS IN THE PROGENY OF
IMPORTED BEEF CATTLE; FIRST DETECTED IN
ISRAEL
Vol. 56 (2) 2001
J. Brenner1 Y. Yaakobovich2 and M. Berenstein2
1. Unit of Neonatal Diseases Prevention
2. Department of Bacteriology, Kimron Veterinary Institute, P. O. Box 19, 50250 Bet Dagan, Israel
Summary
Intestinal chlamydiosis was diagnosed for the first time in Israel in the progeny of imported cattle.
Eighty calves were born to 100 imported dams. Forty calves born at the beginning of the calving
season showed no clinical signs of disease. The 40 remaining calves, born subsequently, developed on
day 5 a watery-yellowish diarrhea tinged with undigested spots of blood (morbidity rate = 0.5). Clinical
signs lasting 5 days were observed. 25 of the sick calves died while the remaining 15 recovered (case
fatality rate = 0.315). Chlamydial antigen was demonstrated in 6 out of 14 samples submitted, and was
identified in feces, synovial fluid, lung and pharyngeal lymph node.
To evaluate whether this type of chlamydial outbreak could be considered as a rare syndrome in Israeli
farms, an attempt to demonstrate chlamydial antigens in the feces of newborn calves less than 10 days
old and suffering from diarrhea, was carried out during a 12 month period.
Only 2 out of 100 diarrheic fecal samples originating from local cattle over a period from January
throughout December 1999, were chlamydial antigen positive (prevalence of 0.02, 95% CI, 0,0.07).
This outbreak of intestinal chlamydiosis in young calves was observed for the first time in Israel and
we conclude that it should be considered as a rare phenomenon.
Introduction
Chlamydiae are obligate, intracellular parasites belonging to the bacterial order of Chlamydiales.
Infection of livestock with chlamydiae may result in pneumonia, abortion, rhinitis, conjunctivitis,
arthritis, or enteritis or in no apparent disease. The intestinal tract is the natural habitat for chlamydia,
mostly causing inapparent infections. The intestine may be an important portal of entry in the
development of systemic infections (1), and chlamydia may occasionally cause severe enteric disease
in calves less than 10 days old (1, 2,3,4).
Hepatic lesions, not necessarily with clinical signs of hepatitis, interstitial pneumonia and
arthritis often accompany watery diarrhea and dehydration. Serosal hemorrhages, mucosal edema and
petechiae are often observed.
The demonstration of chlamydia in fecal samples and internal organs of young calves, born to
imported dams, led us to conduct a study to verify its unusual rare appearance in Israel.
The object of this study was to determine the incidence of intestinal chlamydiosis of diarrheic
young calves less than 10 days old in Israel during a 12 month period (January-December 1999).
Materials and Methods
Materials and Methods
Pathological specimens originating from imported young cattle (Murray Grey) submitted for
detection of chlamydial antigen
Three dead calves 10 days old were brought to Kimron Veterinary Institute (KVI) originated
from a Murray Grey breed imported two years earlier from Australia. These calves belonged to a
Kibbutz farm that owns also two local beef cattle herds and one large dairy cattle herd. No clinical
disease in the neonatal calf rearing units was observed in these three herds.
On post mortem examination, extensive abomasal petechiae were observed in the dead calves
and chlamydial involvement was suspected.
Eleven additional fecal samples of calves less than 10 days old originating from the affected
Australian herd and born towards the end of the calving period were examined for chlamydial antigen.
Six were from diseased calves and 5 from healthy ones.
In addition, all the fecal samples were submitted for routine bacterial and viral diagnosis (5)
(Table 1).
Chlamydial antigen examination of fecal samples from young calves from other herds on
the same farm
Fecal samples were collected from 20 healthy calves up to 10 days old originating from the other 3
herds (2 beef and 1 dairy) belonging to the same farm. The observational period overlapped (partially)
the period during which the clinical manifestations were observed in the imported stock (November
1999-February 2000).
Fecal samples of local Israeli diarrheic calves
Eighty-four fecal samples including 24 from cadavers and 60 feces from diarrheic calves less than <10
day old which arrived to the department of bacteriology at the KVI for routine diagnosis were
examined for chlamydial antigen. In addition, 16 other fecal samples from two herds, 8 samples from
each herd, were included after one positive chlamydia sample in each herd was detected during the
survey.
Chlamydial antigen in pathological material
A commercial kit Cell LPS IF test (Cellab PTY LTD, Brookvale, Australia) based on the detection of
the common group specific chlamydial lipopolysaccharide (LPS) antigen was used. It utilizes a
fluorescein-labeled monoclonal antibody which binds specifically to the organism. The manufacturer
claims 92.5% of specificity and 89.0% of sensitivity when the tests are performed according to
instructions.
This test is recommended by the OIE (6).
Statistics
Proportion of chlamydial positive samples and 95% confidential interval (CI) for each group of
samples were calculated, namely, for those originating from “Israeli” or “foreign” sources. Case
fatality rate (number of deaths/number of cases) and morbidity rate (number of cases/population at
risk) were calculated for the herd (“foreign”) that experienced the intestinal chlamydiosis outbreak.
Results
Identification of intestinal chlamydiosis in imported beef calves (Murray Grey)
In calves born in Israel to imported Australian beef cattle, unusual morbidity and mortality were
observed. A total of 80 calves were born to 100 imported dams. The calving period lasted
approximately 3 months, from October to the end of December 1998. The 40 calves born during the
first half of the calving period, showed no clinical signs of disease. Morbidity suddenly erupted. All the
remaining 40 (morbidity rate = 0.5) calves born thereafter developed on day 5 a watery-yellowish
diarrhea tinged with undigested drops of blood. Twenty-five of them died after an illness lasting 5 days
(case fatality rate = 0.315). Supportive treatment with antibiotics and physiological solutions probably
saved the remaining 15 calves.
Chlamydial antigen was identified in two of three cadavers brought for post mortem examination. This
was demonstrated in the feces and the synovial fluid (no other organs were inspected) of one calf,
while in the other it was found in the feces, lung and pharyngeal lymph node. No attempt at antigen
demonstration was performed on the first cadaver which was precedent before chlamydial disease was
suspected.
Chlamydiae antigen was demonstrated in 3 out of 6 diseased calves and in one out of 5 other healthy
ones. A total of 6 positive cases was demonstrated out of 14 specimens (11 feces and 3 cadavers) tested
(incidence of 0.428, 95% CI, 0.18-0.71).
Table 1 lists other enteropathogens found in the feces of the diseased Murray Grey calves. Only
rotavirus as a major enteropathogen could have been associated and even involved in this outbreak.
They were identified in about 50% of the samples.
Table 1. Microorganisms prevalence in feces of young diarrheic Murray Grey calves
Positive samples
7
Campylobacter Jejumi
1
Cryptosporidium parvum 5
Salmonella Cl
1
Tested Pathogen
Rotavirus
Negative samples
7
5
9
13
Prevalence
50%
20%
35.7%
7.7%
Coranvirus, E. coli K99+ and anaerobic bacteria or other Salmonella spp. were negative.
Chlamydial antigen in fecal samples collected in 1999
Only two out of 100 diarrheic fecal samples originating from local sources, were positive for
chlamydial antigen (prevalence of 0.02, 95% CI, 0,0.07).
Discussion
As reported by others, the majority of calves yielding chlamydia from fecal samples are of apparently
good health and clinically normal (1). The enteritis described in this study and the demonstration of
chlamydial antigen in fecal samples concomitantly with its demonstration in internal organs and
synovial fluid, is consistent with clinical descriptions reported of intestinal chlamydiosis (1,3,4).
However, definitive diagnosis requires isolation of the infective agent from internal organs or detection
of antigen by a specific IF test as was fulfilled in this outbreak (7).
Reggiardo et al., (8) reported chlamydial agents recovered from calves suffering from diarrhea as
young as two days of age. In experimental infection, it was demonstrated that 24-hour-old calves
developed fever, leukocytosis and diarrhea and some mortality after oral exposure (1). Other infected
calves developed watery, mucoid and bloody diarrhea, dehydration and frequently the affected calves
died.
Doughri et al,. (1) and Shewen (2) reported an undifferented diarrheic syndrome produced
experimentally that had ensued in dehydration and death in calves under two weeks of age.
Routine examination for intestinal chlamydiosis in fecal samples originating from young calves
younger than 10 days is performed periodically. Until 1999, clinical intestinal chlamydiosis of young
calves was considered as very rare, if at all, in Israel. Our current data confirm that this epidemiological
situation was not changed materially.
With regard to the identification of the chlamydia, there are no commercially available reagents that
can distinguish between C. psittaci and C. pecorum or between different strains of C. psittaci. These
strains cause dramatically diverse disease syndromes and have greatly varying pathogenic properties
(9).
In this outbreak, we assume that the strain involved was C. pecorum according to the new classification
reviewed by Everett (9). Based on the latter, C. pecorum is responsible for lesions encountered in the
intestine, joints and lymph nodes of cattle and other farm animals. We have demonstrated the presence
of chlamydial antigen in all these organs and in the lung of newborn calves that was examined.
The identification of chlamydial antigen in fecal samples in more than one case from calves originating
from imported cattle, confounds the findings in fecal samples originating from the local diarrheic
young calves. Thus, it seems that the intestinal chlamydiosis of the imported calves was an unusual
event in Israeli herds.
Based on our records, no problems related to intestinal chlamydiosis have been encountered in Israel
during the last 25 years. We have been tested, at random, few dozens of fecal samples of diarrheic
calves less than 10 days of age for the presence of chlamydial antigen. They resulted negative (personal
communication). Furthermore, we were unable to confirm its presence in pathogenic fecal samples
collected during 1999 in such a magnitude that could be considered as an outbreak of intestinal
chlamydiosis in calves. With regard to the two identifications that were found during our observational
period on two different farms, the findings might be considered as sporadic events. In fact we failed to
demonstrate chlamydial antigen in any of the additional sixteen fecal samples, taken on these same
sites in successive order. These cases did not meet the “outbreak” criteria. Moreover, no clinical
manifestations consistent with intestinal chlamydiosis were observed on these two above-mentioned
farms.
The presence of this pathogen in calves originating from imported cattle remains unexplained as we
failed to demonstrate Chlamydial antigen presence in fecal samples taken from the imported dams
(data not shown).
Some authors propose that although ruminants become infected orally, newborn calves are probably
infected in utero or even transplacentally (8,10).
The in utero infection theory may explain the apparent absence, so far, of chlamydial transmission
from the affected herd to the other 3 herds on the same farm. It also strengthens some claims that
vertical transmission is the major route of transmission of intestinal chlamydiosis (8,10). Indeed we
were unable to demonstrate chlamydial antigen in young calves originating from the other three herds
on the same farm. Moreover, no outbreaks of undifferented diarrhea were observed during or after the
outbreak in the imported stock.
Diarrhea, which by its nature is multi-factorial and therefore several enteropathogens in combination
might be isolated/demonstrated. Other enteropathogens, which were demonstrated in the feces of the
affected calves, especially rotavirus and cryptosporidia might cause diarrhea alone or in combination
with other pathogens
References
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polyarthritis in calves. J. Infect. Dis. 123: 41-50.
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