Pertussis

Bordetella pertussis

http://www.hhmi.princeton.edu/sw/2002/psidelsk/Microlinks.htm

Whooping Cough
Also known as Pertussis
Outbreaks first described in the 16th Century
Major cause of childhood fatality prior to vaccination

paaap.org/immunize/ course/slide27.html

Pertussis
Highly contagious respiratory infection caused by Bordetella pertussis
Outbreaks first described in 16th century
Bordetella pertussis isolated in 1906
Estimated >300,000 deaths annually worldwide


Pertussis Pathogenesis
Attachment to cilia of ciliated epithelial cells in respiratory tract

Pertussis antigens allow evasion of host defenses (lymphocytosis but impaired chemotaxis)

Local tissue damage in respiratory tract

Systemic disease may be toxin mediated

Pertussis Clinical Features
Incubation period 5-10 days (up to 21 days)

Insidious onset, similar to minor upper respiratory infection with nonspecific cough

Fever usually minimal throughout course

Pertussis Clinical Features

Catarrhal stage 1-2 weeks
Paroxysmalcough stage 1-6 weeks
Convalescence Weeks to months

Pertussis in Adults

Accounts for up to 7% of cough illnesses per year
Disease often milder than in infants and children
Adults often source of infection for children


Pertussis Complications*
Condition
Pneumonia
SeizuresEncephalopathy
Death
Hospitalization
Percent reported
5.2
0.8
0.1
0.2
20
*Cases reported to CDC 1997-2000 (N=28,187)

Pertussis Epidemiology

Reservoir Human
Adolescents and adults
Transmission Respiratory droplets
Airborne rare
Communicability Maximum in catarrhal stage
Secondary attack rate
up to 90%


Diagnosis
Isolation by culture
PCR
Direct fluorescent antibody
Serological testing

http://medinfo.ufl.edu/year2/mmid/bms5300/images/d7053.jpg

Treatment
Antibiotic therapy
Erythromycin
Azithromycin and clarithromycin

http://www.aboutthatbug.com/AboutThatBug/files/CCLIBRARYFILES/

FILENAME/0000000032/033_lg.jpg

http://www.vet.purdue.edu/bms/courses/lcme510/chmrx/macrohd.htm

Prevention
The primary method of prevention for pertussis is vaccination. There is insufficient evidence to determine the effectiveness of antibiotics in those who have been exposed but are without symptoms. Preventative antibiotics, however, are still frequently used in those who have been exposed and are at high risk of severe disease (such as infants).