Treatment


How is plague treated?

As soon as a diagnosis of suspected plague is made, the patient should be isolated, and local and state health departments should be notified. Confirmatory laboratory work should be initiated, including blood cultures and examination of lymph node specimens if possible. Drug therapy should begin as soon as possible after the laboratory specimens are taken. The drugs of choice are streptomycin or gentamycin, but a number of other antibiotics are also effective (please read the box below for more information about plague treatment).

Those individuals closely associated with the patient, particularly in cases with pneumonia, should be traced, identified, and evaluated. Contacts of pneumonic plague patients should be placed under observation or given preventive antibiotic therapy, depending on the degree and timing of contact.

Source : CDC's home page on Plague


Additional information on plague treatment

Different modalities of treatment are used:

Specific therapy

Aminoglycosides: streptomycin and gentamicin

Streptomycin is the most effective antibiotic against Y. pestis and the drug of choice for treatment of plague, particularly the pneumonic form. Therapeutic effect may be expected with 30 mg/kg/day (up to a total of 2 g/day) in divided doses given intramuscularly, to be continued for a full course of 10 days of therapy or until 3 days after the temperature has returned to normal. Gentamicin has been found to be effective in animal studies, and is used to treat human plague patients.

Chloramphenicol

Chloramphenicol is a suitable alternative to aminoglycosides in the treatment of bubonic or septicaemic plague and is the drug of choice for treatment of patients with Y. pestis invasion of tissue spaces into which other drugs pass poorly or not at all (such as plague meningitis, pleuritis, or endophthalmitis). Dosage should be 50 mg/kg/day administered in divided doses either parenterally or, if tolerated, orally for 10 days. Chloramphenicol may be used adjunctively with aminoglycosides.

Tetracyclines

This group of antibiotics is bacteriostatic but effective in the primary treatment of patients with uncomplicated plague. An oral loading dose of 15 mg/kg tetracycline (not to exceed 1 g total) should be followed by 25-50 mg/kg/day (up to a total of 2 g/day) for 10 days. Tetracyclines may also be used adjunctively with other antibiotics.

Sulfonamides

Sulfonamides have been used extensively in plague treatment and prevention; however, some studies have shown higher mortality, increased complications, and longer duration of fever as compared with the use of streptomycin, chloramphenicol or tetracycline antibiotics. Sulfadiazine is given as a loading dose of 2-4 g followed by a dose of 1 g every 4-6 hours for a period of 10 days. In children, the oral loading dose is 75 mg/kg, followed by 150 mg/kg/day orally in six divided doses. The combination drug trimethoprim-sulfamethoxazole has been used both in treatment and prevention of plague.

Fluoroquinolones

Fluoroquinolones, such as ciprofloxacin, have been shown to have good effect against Y. pestis in both in vitro and animal studies. Ciprofloxacin is bacteriocidal and has broad spectrum activity against most Gram-negative aerobic bacteria, including Enterobacteriaceae and Pseudomonas aeruginosa, as well as against many Gram-positive bacteria. Although it has been used successfully to treat humans with Francisella tularensis infection, no studies have been published on its use in treating human plague.

Other classes of antibiotics (penicillins, cephalosporins, macrolides)

These classes of antibiotics have been shown to be ineffective or of variable effect in treatment of plague and they should not be used for this purpose.

Supportive therapy

The clinician must prepare for intense supportive management of plague complications, utilizing the latest developments for dealing with Gram-negative sepsis. Aggressive monitoring and management of possible septic shock, multiple organ failure, adult respiratory distresssyndrome (ARDS) and disseminated intravascular coagulopathy should be instituted.

Treatment of plague during pregnancy and in children

With correct and early therapy, complications of plague in pregnancy can be prevented. The choice of antibiotics during pregnancy is confounded by the potential adverse effects of three of the most effective drugs.

  • Streptomycin may be ototoxic and nephrotoxic to the foetus. Tetracycline has an adverse effect on developing teeth and bones of the foetus.
  • Chloramphenicol carries a low risk of "grey baby" syndrome or bone-marrow suppression.
  • Experience has shown that an aminoglycoside judiciously administered is effective and safe for both mother and foetus, and in children.
  • Because of its safety, intravenous or intramuscular administration, and ability to have blood concentrations monitored, gentamicin is the preferred antibiotic for treating plague in pregnancy.

Prophylactic therapy

Persons in close contact with pneumonic plague patients, or persons likely to have been exposed to Y. pestis-infected fleas, to have had direct contact with body fluids or tissues of a Y. pestis-infected mammal, or exposed during a laboratory accident to known infectious materials should receive antibiotic preventive therapy, if the exposure was in the previous six days.

The preferred antimicrobials for preventive or abortive therapy are the tetracyclines, chloramphenicol, or one of the effective sulfonamides.

True prophylaxis, i.e. the administration of an antibiotic prior to exposure, may be indicated when persons must be present for short periods in plague-active areas under circumstances in which exposure to plague sources (fleas, pneumonic cases) is difficult or impossible to prevent.

Source : WHO's Plague Manual (Chapter 3)