Communicable disease factsheets

Pertussis

Pertussis (whooping cough) is a serious, sometimes fatal, respiratory infection caused by the bacterium, Bordetella pertussis. This fact sheet covers: the disease and its agent; spread of infection; prevention; surveillance and reporting.

The disease and its agent

Pertussis (whooping cough) is a serious, sometimes fatal, respiratory infection caused by the bacterium, Bordetella pertussis. World-wide pertussis is responsible for about 250,000 deaths in children annually.

In most cases the disease usually begins with cold-like symptoms, which progresses to a paroxysmal cough with a inspiratory whoop. Babies under 12 months of age often require admission to hospital. Complications include convulsions, pneumonia, coma, inflammation of the brain, and permanent brain damage. Around one in every 200 children under six months of age who contracts pertussis will die. The most common cause of death is from pertussis pneumonia.

Spread of infection

Pertussis is a highly infectious disease, typically transferred to 70-100 per cent of susceptible household contacts. Infection is spread by direct contact with droplets from the nose and throat of an infected person. The incubation period is commonly 7-10 days and not more that 21 days. A case is infectious from 7 days after exposure to 3 weeks after the onset of typical paroxysms. Children should be excluded from child care until well and until five days after starting antibiotic treatment.

During epidemics cases occur mainly in school aged children, who then pass it on to younger siblings. Adolescents and adults may also be reservoirs of infection. In the 1993-1996 Australian epidemic almost 50 per cent of reported cases were in adults and children over 9 years of age.

Prevention

The incidence and severity of pertussis is reduced by immunisation. The vaccine is usually given as a trivalent vaccine (DTP), in which pertussis is combined with diphtheria and tetanus vaccines. The primary course consists of 3 doses, the first at 2 months of age and then at intervals of 2 months. Booster doses are recommended at 18 months and at the time of school entry (4-5 years).

Information about outbreak control, exclusion periods and chemoprophylaxis of contacts is provided in the CDNANZ publication Control of Pertussis in Australia, 1998. .

Surveillance and reporting

Reported cases are collected through the National Notifiable Diseases Surveillance System, for national reporting through the Communicable Diseases Intelligence (CDI).  

Year	ACT	NSW	NT	Qld	SA	Tas	Vic	WA	Total
1991	7	45	0	131	44	2	65	43	337
1992	9	195	1	208	67	27	140	92	739
1993	45	1405	7	597	1126	58	513	239	3990
1994	19	1534	138	1937	982	26	447	568	5651
1995	34	1342	174	1416	389	118	376	448	4297
1996	33	1112	16	766	690	30	1201	183	4031
1997	115	3536	24	1786	1643	119	1683	1180	10086
1998	7	1117	5	622	248	17	209	247	2472