 |  |
| Quick Links |
 Home |
| Objectives |
| Research |
| Organization |
| Achievements |
| Man power Development |
| Contact |
| Plague |
| plague | Classification of Bio-weapons | Bioterrorism related links |
Yersinia pestis, the causative agent of plague, if used as a weapon, could cause disease and death in sufficient numbers to cripple an entire region.The potential use of plague as a biological weapon is of great concern after few deaths reported in Himachal Pradesh, India.
Plague as a Biological weapon: The epidemiology of plague following its use as a biological weapon would differ substantially from that of naturally occurring infection. Intentional dissemination of plague would most probably occur via an aerosol of Y pestis.
Distinction between naturally occuring plague and artificially disseminated plague.
- Occurrence of cases in locations not known to have enzootic infection
- persons without known risk factors
- and in the absence of prior rodent deaths.
Y pestis is a nonmotile, gram-negative bacillus, sometimes coccobacillus, that shows bipolar (also termed safety pin) staining with Wright, Giemsa, or Wayson stain
Y pestis is a lactose nonfermenter, urease and indole negative, and a member of the Enterobacteriaceae family.
Vector (Xenopsylla cheopis)
- Xenopsylla cheopis
| Bubonic Plague |
- characterized by chills, fever, vomiting, diarrhea, and the formation of buboes.
- Bacteria invade lymph nodes, which swell and are called Buboes
- Blood vessels break, causing internal bleeding
- Dried blood under the skin turns black, hence the name, "Black Death"
- Spread is slow from person-to-person
- Mortality is very high (up to 75%) in untreated cases
- Early treatment with antibiotics is very effective
| Septicemic Plague |
- Gastrointestinal symptoms, e.g., nausea, vomiting, diarrhea, and abdominal pain are comman in septicemic plague.
- It is usually fulminant and fatal.
- Refractory hypotension, renal shutdown, obtundation, and other signs of shock are preterminal events.
| Pneumonic Plague |
- This is the most rapidly developing and fatal form of plague.
- characterized by cough, sputum production, increasing chest pain, tachypnea, and dyspnea.
- sputum is usually watery or mucoid, frothy, and blood-tinged.
- Bacteria invades victim's lungs
- lungs fill with frothy bloody liquid
- Localized pulmonary involvement is followed by a rapid segmental consolidation in the lobes of the same and opposite lungs.
- Spreads rapidly from person-to-person
Diagnostic specimens for smears include
- Blood (In all Patients)
- Lymph nodes (in patients with suspected buboes)
- Sputum samples or tracheal aspirates (in those with suspected pnemonic plague)
| Plague cases can be confirmed |
- If small gram-negative and/or bipolar-staining coccobacilli are seen on a smear taken from affected tissues
- If immunofluorescence stain of smear or material is positive (greater change in serum antibodies) for the presence of Yersinia pestis F1 antigen.
- If only a single serum specimen is tested and the anti-F1 antigen titer by agglutination is >1:10.*
- ELISA is useful in early detection of IgM and IgG antibodies to Y.pestis
| Drug | Dosage | Interval (hours) | Route of Administration | ||||||||||||||||||||||||||||||||||||||||||
| Streptomysin | |||||||||||||||||||||||||||||||||||||||||||||
| Adults | 2 g/day | 12 | IM
| Children | 30 mg/kg/day | 12 | IM
| Gentamicin |
| Adults | 3 mg/kg/day | 8 | IM or IV
| Children | 6.0 - 7.5 mg/ kg/day | 8 | IM or IV
| Infants / neonates | 7.5 mg/kg/day | 8 | IM or IV
| Tetracycline |
| Adult | 2g/day | 6 | PO
| Children >= 9 yr | 25-50 mg/kg/day | 6 | PO
| Chloramphenicol |
| Adults | 50 mg/kg/day | 6 | PO or IV
| Children >=1 yr | 50 mg/kg/day | 6 | PO or IV
| | ||||