Abstract
Brucellosis is considered to be the most widespread zoonosis throughout the world and is caused by
different species of the genus Brucella. Brucellosis causes a great economic loss to the livestock industries
through abortion, infertility, birth of weak and dead offspring, increased calving interval and reduction of
milk yield and it is endemic in Bangladesh. The present research was carried out to estimate the prevalence
and to identify the risk factors of brucellosis along with determination of genetic diversity in Bangladesh.
The study was conducted between March 2012 to February 2015 (Three types of populations). Out of
1043, 28 milk samples (2.68 %) and 23 serum samples (2.21 %) were positive by MRT and RBT
respectively. The highest prevalence was 3.05% in the Holstein Friesian cross using MRT, while 2.49% in
the Holstein Friesían cows using RBT. Age-wise prevalence of brucellosis by MRT and RBT were 2.06%
and 1.23%, respectively in 1-4 years age group. On the other hand prevalence of brucellosis based on MRT
and RBT were significantly higher (2.88% and 2.50%) in > 5 years age group (p≤0.01) than those of other
age groups. Based on parity, significantly higher prevalence 3.07% and 2.58% of MRT and RBT were
obtained respectively in parity 3-5 in comparison to other parity group (p≤0.01). It is, however, obvious
that although the MRT is 1st-line screening tests for brucellosis in cows in some countries, their lack of
specificity is of concern. Therefore, the requirement for other confirmatory tests that are more specific
were used for the diagnosis of the disease, especially in Bangladesh. All samples were cultured in the
Department of Medicine, Department of Microbiology & Hygiene, Bangladesh agricultural University,
Mymensingh and OIE reference laboratory for brucellosis but did not identified the bacteria. In case of
human brucellosis 350 blood samples were tested with RBT, SAT, CFT, iELISA, conventional PCR, real
time PCR in the OIE Reference Laboratory for Brucellosis, Federal Research Institute for Animal Health
but were negative in all tests. In case of livestock and human brucellosis bacteria were cultured both in
OIE Reference Laboratory for Brucellosis, Federal Research Institute for Animal Health, but bacteria were
not isolated. In case of goat all samples were tested with RBT, SAT, CFT, İELISA, conventional PCR, real
time PCR in OIE Reference Laboratory for Brucellosis, Federal Research Institute for Animal Health,
Friedrich-Loeffler-Institut, (FLI), but were negative in all tests. Out of total 913 cattle and 99 buffalo sera,
48 cattle and 7 buffalo sera showed positive reaction with RBT having overall prevalence of brucellosis
5.3% (95% Confidence Interval (CI): 3.87-7.38) in cattle and 7.1% (95% CI: 2.89-14.03) in buffalo. Out of
48 RBT positive sera of cattle 21.05% were B. abortus positive whereas out of 7 RBT positive buffalo sera
57.14% were B. abortus positives. The difference in detection level of B. abortus from cattle and buffalo
sera was statistically significant (p>0.02).The odds of getting B. abortus DNA from RBT positive buffalo
sera was 7.61 times higher than the same from cattle sera.This report confirms that B. abortus is endemic
in cattle and buffaloes in Bangladesh. It can be concluded that a combinations of real time PCR with SAT
and iELISA should be applied for detection of brucellosis in cattle and buffaloes from Bangladesh.