European Journal of Applied Sciences 8 (6): 347-355, 2016
ISSN 2079-2077
© IDOSI Publications, 2016
DOI: 10.5829/idosi.ejas.2016.347.355
Corresponding Author: Simegnew Adugna, College Veterinary Medicine, Haramaya University,
P.O. Box 138, Dire Dawa, Ethiopia. E-mail: adusim@yahoo.com.
347
A Review of Bovine Leptospirosis
Simegnew Adugna
College Veterinary Medicine, Haramaya University, P.O. Box 138, Dire Dawa, Ethiopia
Abstract: Leptospirosis is caused by bacteria of genus Leptospira. It is a potentially zoonotic disease and
affects humans and animals and has worldwide occurrence. The source of infection is an infected animal which
contaminates the premises by infective urine, aborted fetuses and uterine discharges. Risk factors like animal
risk factors and environmental and management factors affect the relationship between host and agent. It has
major economic impact in farm animals which is associated with abortion, stillbirth and birth of weak neonates,
with a high death rate. The clinical signs may be acute, subacute, or chronic and is usually associated with two
serovars, Pomona or Hardjo. The most prominent post mortem findings with leptospirosis are anemia and
icterus. A variety of serological tests can be used for diagnosis of leptospirosis such as ELISA and
Immunofluorescence; however, the microscopic agglutination test is still the most widely used as reference
method in the determination of antibody titer. Many antimicrobial drugs are effective for the treatment. Control
methods are useful to avoid and eradicate this disease, which includes biosecurity and biocontainment,
occupational hygiene and immunization.
Key words: Cattle Leptospirosis Risk Factor Zoonosis
INTRODUCTION of skin or mucus membranes with urine and to a lesser
Leptospirosis is a worldwide zoonotic disease of Ingestion of infected animals and venereal transmission
domestic animals and wildlife. It is caused by a spirochete can also be routes of infection. Infections can be readily
bacteria classified under the Leptospira, of which there established via the conjunctiva, vaginal mucosa, or skin
are approximately 17 species. The term Leptospira abrasions. Disease outbreaks in small herds are often self-
interrogans is used to describe the broad group of limiting. However, control of enzootic infections in large
pathogenic leptospires associated with animal hosts. herds generally requires immunization, chemotherapy and
Serovars are primary grouping below the species fencing the herd from surface waters and limiting contact
designations [1]. with rodents and others wildlife [1].
The same disease processes are seen in all animals The microscopic agglutination test (MAT) is the
although some species are more resistant to acute commonly used serological test for diagnosis. It measures
infections. Infections may be asymptomatic or cause both IgM and IgG antibodies. An enzyme linked
various signs, including fever, icterus, haemoglobinuria, immunosorbent assay (ELISA) measures IgM and IgG is
renal failure, infertility, abortion and death. After acute helpful in distinguishing titers due to natural infections
infection, leptospires frequently localize in the kidneys or from those due to vaccination. Demonstration of
reproductive organs and are shed in the urine, sometimes leptospires in urine or tissues is helpful in diagnosis.
in large numbers for months or years, especially with host Older techniques like dark field microscopy of urine are
adapted serovars. Because the organisms survive in not sensitive or specific. Newer tests include fluorescent
surface waters, such as swamps and rivers, for extended antibody techniques and polymerase chain reaction (PCR)
periods, the disease is often waterborne. The organism [3]. Definitive confirmation of leptospirosis is made by
survives well in mud and moist soil, such river banks, isolation of the organism from urine or tissues of infected
floods frequently result in an increase of disease animals. However, because leptospires are not easily
outbreaks [2]. Infection is commonly acquired by contact cultured, isolation is not usually performed in clinical
extent, by intake of urine-contaminated feed or water.