Chlamydia abortus

Chlamydia abortus is a species of Chlamydiaceae, a family of obligate intracellular bacteria, which causes enzootic abortion in sheep and goats, and can also infect cattle and pigs. It is a significant zoonotic agent, capable of causing abortion in pregnant women who come into contact with infected animals or animal products. This organism was previously known as Chlamydophila abortus and is still referred to by this name in much of the literature.

Etiology

Chlamydia abortus is characterized by its unique life cycle, which alternates between an infectious, elementary body (EB) and a replicative, reticulate body (RB). The EB is adapted for survival outside the host cell, while the RB is the active, replicative form within host cells. Infection occurs when susceptible animals or humans inhale aerosols or ingest materials contaminated with EBs.

Epidemiology

The disease caused by Chlamydia abortus, known as ovine enzootic abortion (OEA), is prevalent in many parts of the world, including Europe, the Middle East, and North America. The primary route of transmission is through ingestion or inhalation of the organism from the environment, contaminated by birth products, such as placenta and fetal fluids, from infected animals.

Clinical Signs and Diagnosis

In sheep and goats, infection typically results in late-term abortion, stillbirth, or the birth of weak lambs or kids. Infected animals may also exhibit signs of systemic illness, including fever, anorexia, and lethargy. In humans, Chlamydia abortus can cause flu-like symptoms and, in pregnant women, may lead to miscarriage or premature birth.

Diagnosis of Chlamydia abortus infection is based on clinical signs, history of exposure, and laboratory tests. Polymerase chain reaction (PCR) assays, culture methods, and serology are commonly used to detect the presence of the organism or antibodies against it.

Prevention and Control

Control of Chlamydia abortus infection in livestock is primarily achieved through good husbandry practices, including the isolation of aborting animals, proper disposal of birth products, and sanitation of contaminated areas. Vaccination of susceptible animals is also an effective preventive measure. In humans, avoiding contact with potentially infected animals and their products is crucial for preventing infection.

Treatment

The treatment of Chlamydia abortus infection involves the use of antibiotics. Tetracyclines are commonly prescribed for both animals and humans. Early diagnosis and treatment are essential for preventing the severe consequences of infection.

Public Health Significance

Chlamydia abortus poses a significant public health risk, particularly to pregnant women working in agriculture or veterinary settings. Education on the risks associated with handling potentially infected animals and the importance of personal protective equipment is vital for preventing zoonotic transmission.