| Clinical
Features |
Highly communicable,
vaccine-preventable disease that lasts for many weeks and is
typically manifested in children with paroxysmal spasms of
severe coughing, whooping, and posttussive vomiting. |
| Etiologic
Agent |
Bordetella pertussis, a
gram-negative coccobacillus. |
| Incidence |
This disease results in high morbidity
and mortality in many countries every year. In the United
States, 5000-7000 cases are reported each year. Incidence of
pertussis has increased steadily since the 1980s. The incidence
in 2002 was 3.01/100,000 when 8,296 cases of pertussis were
reported. |
| Complications |
Major complications are most common
among infants and young children and include hypoxia, apnea,
pneumonia, seizures, encephalopathy, and malnutrition. Young
children can die from pertussis and 13 children died in the
United States in 2003. Most deaths occur among unvaccinated
children or children too young to be vaccinated. |
| Transmission |
Occurs through direct contact with
discharges from respiratory mucous membranes of infected
persons. |
| Risk
Groups |
Children who are too young to be fully
vaccinated and those who have not completed the primary
vaccination series are at highest risk for severe illness. Like
measles, pertussis is highly contagious with up to 90% of
susceptible household contacts developing clinical disease
following exposure to an index case. Adolescents and adults
become susceptible when immunity wanes. |
| Surveillance |
National reporting through the
National Electronic Telecommunications System for Surveillance (NETSS)
and through several Enhanced Surveillance Sites throughout the
United States. |
| Trends |
Pertussis is an endemic illness. In
the United States epidemics occur every 3-5 years. The most
recent epidemic occurred in 1996. Overall increase in cases
since 1990, with disproportionate increase in adolescents and
adults. |
| Challenges |
Understanding pertussis pathogenesis
and immunity; protecting infants from severe pertussis; control
of pertussis outbreaks; diagnosing pertussis in a timely,
accurate, and standardized fashion; understanding the true
burden of disease in different age and socioeconomic groups;
evaluating the impact of a licensed pertussis vaccine in persons
> 14 years of age; evaluating the impact of acellular
vaccines on prevention programs; and determining the prevalence
of erythromycin-resistant B. pertussis. |
| Opportunities |
Characterize strains using newly
developed molecular typing methods (e.g., pulsed-field gel
electrophoresis and gene-sequencing analysis) to elucidate
epidemiology and virulence factors, examine isolates for
antimicrobial susceptibility and to identify resistance
mechanisms; study transmission of pertussis within populations
(e.g., how adults/adolescents transmit the organism to others);
study efficacy of acellular pertussis vaccines among persons >
14 years of age; study effectiveness of acellular pertussis
vaccines to control outbreaks; apply/evaluate new diagnostic
tests. |