Properties

Pathogenesis

Clinical findings

Laboratory diagnosis

Treatment & Prevention

Small gram-negative rod

Encapsulated

An infection of rodents particularly rats which may be transmitted to man by the rat flea.

Local draining lymph node becomes infected & a painful swelling develops – a bubo.

Invasion of bloodstream gives rise to fatal septicaemia:

- organisms form abscesses in many organs.

- coagulation & cutaneous haemorrhages.

Spread to lungs results in pneumonic plague, both fatal & infectious.

Droplet spread direct from person to person.

Disease: bubonic plague

Begins with pain & swelling of lymph nodes draining site of flea bite.

Systemic symptoms: high fever, myalgias, & prostration.

Affected nodes enlarge & become tender.

Septic shock & pneumonia are main-life threatening events.

Smear & culture of blood or pus from bubo.

Fluorescent-antibody staining used to identify organism in tissues.

Rise in antibody titer to envelope antigen.

Streptomycin + tetracycline

Prevention:

- control spread of rats.

- avoid contact with dead wild rodents.