Plague is an infectious disease transmitted to man by infected rat fleas. It is primarily a zoonotic disease. The causative agent is Y. pestis which is present in the bubo’s, blood, spleen and liver of infected persons.
Forms of plague
Plague occurs in three forms: 1) Bubonic plague 2) Septicae- mic plague 3) Pneumonic plague. Bubonic plague is the common type of plague. It is characterised by fever, prostration, inflammation and swelling of lymph nodes.
Transmission: Plague is epizootic in rats. The fleas feed on rats. The infected rats die and then the fleas leave the rats. When healthy rats run away the fleas starve. So they bite human beings who are thus infected. The bacilli which are regurgitated or excreted in the faces of fleas may enter through abrasions.
Pneumonic plague is transmitted by droplet infection,
Prevention and control
1. Control of cases by early diagnosis, notification, isolation, treatment and disinfection (of sputum and discharges),
2. Control of fleas with insecticides like DDT or BHC.
3. Control of rodents with rodenticides and by trapping.
4. Vaccination with Haffkine’s anti-plague vaccine.
5. Chemoprophylaxis with tetracycline or sulfonamides
6. Health education about plague and the involvement of rodents.