Tetracycline given as prophylaxis
Live attenuated vaccine are used
Streptomycin given in treatment
Xenopsylla cheopis is major vector
Ans:B.)Live,attenuated vaccine are used..
The patient is suffering from Plague.Safety pin appearance is seen in the microscopic image.
- It is a zoonotic disease that primarily affects rodents; humans are incidental hosts.
- Reservior is wild rat.(Tatera indica).
- Transmitted to humans by the bite of an infected rat flea.
- Rat flea can survive upto 4 years in rat burrows under optimum conditions.
- Partially blocked Flea is most dangerous for transmitting plague.
- Propogative type of trasmission involved in the case of plague in rat flea
- Xenopsylla cheopis, also known as the tropical rat flea, the primary vector for bubonic plague .
- Caused by Yersinia Pestis.
- Y pestis is a nonmotile, pleomorphic, gram-negative coccobacillus that is nonsporulating.
- The bacteria elaborate a lipopolysaccharide endotoxin, coagulase, and a fibrinolysin, which are the principal factors in the pathogenesis of plague.
- The following are the modes of plague transmission in humans:
- Bites by fleas
- Exposure to humans with pneumonic plague
- Handling of infected carcasses
- Scratches or bites from infected domestic cats
- Exposure to aerosols containing plague-causing bacilli.
- Bubonic plague
- This is the most common presentation of plague.
- The incubation period varies but usually ranges 2-6 days.
- There is a sudden onset of high fever, chills, and headache.
- Patients with this type experience body aches, extreme exhaustion, weakness, abdominal pain, and/or diarrhea.
- Painful, swollen lymph glands (buboes) arise, usually in the groin (most common site), axilla, or neck.
- Septicemic plague
- In septicemic plague, bacterial endotoxins cause disseminated intravascular coagulation (DIC).
- Pneumonic plague
- It is highly contagious and transmitted by aerosol droplets.
- Meningeal Plague.
- Pharyngeal Plague.
- Bubonic plague
- Y pestis may be observed on a peripheral blood smear.
- Smear stained with Wright-Giemsa reveals rod-shaped bacteria.
- A Wayson stain demonstrates the typical “safety pin” appearance (bipolar staining) of the bacterium.
- Gram stain shows small gram-negative coccobacilli.
- Streptomycin is the drug of choice, gentamicin can be used when streptomycin is not readily available; tetracyclines and chioramphenicol are alternative choices.
- Prophylaxis for health personnel working in a plague ward is vaccination.
- Plague vaccine
- The WHO recommends that under all circumstances, vaccinaion should be only for the prevention, not the control of human plague.(Most important measure to control epidemic rodent control)
- To be effective, vaccination should be carried out at least a week before an anticipated outbreak, and the vaccine should be given in 2 doses.
- Killed plague vaccine is used.
- The vaccine is given subcutaneously in two doses at interval of 7 to 14 days.
- Immunity starts 5 to 7 days after inoculation, and lasts for about 6 months.
- Booster doses are recommended six-monthly for persons at continuing risk of infection.
- Plague vaccine
- Postexposure prophylaxis
- Chemoprophylaxis using tetracycline or chioramphenicol .
- Cheopis Index for estimating explosion of plague:
- It is the average number of X. cheopis per rat. It is a specific flea index, so it is a more significant index than total flea index. If this index is more than one, it is regarded as indicative of potential explosiveness of the situation, should a plague outbreak occur.