Pertussis (whooping cough) is a highly contagious bacterial infection caused by Bordetella pertussis. The disease derives its name from the "whoop" sound made from the inspiration of air after a cough. The whoop is generally quite coarse, but may be high-pitched in babies and children. As well as being very distressing and uncomfortable for those affected, the disease still carries a significant mortality, even in countries where vaccination is almost universal.
Where is pertussis usually found?
Pertussis is endemic throughout the world, with developing countries showing highest incidence, though statistics remain unreliable. A resurgence of the disease has been well documented in
many industrialised countries, including those with well developed immunisation programs.
common is pertussis?
Increasingly common. In the US, more than 25,000 cases were reported, up from about 1000 in 1976, the low point. Pertussis is often mistaken for a cold or the flu; frequently misdiagnosed and probably seriously underreported.
How is pertussis transmitted?
Transmission is usually by contact with respiratory droplets, though it can occur through contact with freshly contaminated articles from an infected person. No animal or insect vectors are involved.
pertussis be spread from person-to-person?
Very easily, with infection rates of about 80% of those close to an affected person.
is most at risk from pertussis?
Infants and young children are most susceptible to pertussis morbidity and mortality. Infants younger than six months, who have not yet received three doses of the 'triple vaccine' (diphtheria-tetanus-pertussis) and under-vaccinated preschool children have been at highest risk. Pertussis infection rates dropped dramatically after the whole cell pertussis vaccine came into widespread use, and an all-time low in reported cases in the United States was reached in 1976.
There is some evidence that the majority of patients now infected with Bordetella pertussis are adults, with studies confirming pertussis as a cause of persistent cough among teenagers and adults. Many affected adults were born in an era of low immunisation coverage, with waning immunity in those who were vaccinated.
Increasing fear and distrust of government vaccination programmes is undoubtedly contributing, with the illogical insistence on the triple vaccine or nothing possibly being the greatest single factor. There is also evidence that healthcare workers are unwilling to 'encourage' vaccination, as many share the parents' doubts.
Interestingly, all these doubts and fears are usually described by medical academics as 'misconceptions' despite the lack of open debate on the issues. Debate has largely been restricted to witch-hunting those within the profession who speak out; though, it has to be admitted, much of the scaremongering has been misinformed and unhelpful, as it has disratced from the real issues.
What are the
symptoms of pertussis?
Pertussis is a serious illness, not only for infants, but also for children and adults.
Initially, it may present like the common cold; runny nose, sneezing often with congestion or a mild cough. Severe coughing starts after a week or two, and in small children and infants, and excessive exhalation due to continuous coughing leads to a "whooping" sound as air is forcably inhaled.
Hospitalization is required for half of all infected infants under one year, and 20% of infants progress to pneumonia. Convulsions occur in about one per cent.
Dehydration, ear infections and loss of appetite may feature.
When is it necessary
to contact a doctor?
Those who have heard the 'whooping' will always know when to call the doctor; but any abnormal breathing sounds in a sick infant or small child should be taken seriously. Unfortunately, not all infants present with classic symptoms. Fever or prolomged respiratory symptoms should be investigated, even at the risk of exasperating your doctor!
What are the long term
effects of pertussis?
Coughing may last for months, and medicines have little effect. Recovery is slow, and attacks may recur later.
Most people recover, but permanent lung damage may occur, particularly in premature babies or people with lung disease. Convulsions and inflammation of the brain may occur in infants, and can lead to permanent damage..
What is the mortality
rate for pertussis?
Probably no more than 40 deaths per year in the USA, nearly all infants; a similar proportion in most countries with a vaccination programme. Most should be considered as avoidable deaths.
How is pertussis diagnosed?
Initial diagnosis is by clinical signs - the 'whoop' is diagnostic in itself - but confirmation is by taking a swab from deep inside the nose. B. pertussis can be identified by genetic test or laboratory culture.
there a treatment for pertussis?
Treatment is by five days of antibiotic. The patient will not be contagious even the cough persists.
Is there a
way to prevent infection?
The vaccination is very effective; but the benefits reduce over the next 5-7 years; a child who has been immunised as an infant is likely to catch the disease in an attenuated (weakened) form, if in contact with the infection - but will still be infectious to unprotected children.
If a parent has concerns about vaccination, it is important to discuss the issues with a health professional; while there are risks with the accination, there are also risks associatedwith not being vaccinated.
Vaccination progammes work on the basis that if all are vaccinated, the risks are small - though large for those who have problems, of course - it is time there was much more honesty, which would ultimately lead to fewer concerned parents, fewer missed vaccinations, and fewer cases of whooping cough!
What is the pertussis
The first effective pertussis vaccine was developed in the 1930s and was in widespread use by the late-1940s, combined with diphtheria and tetanus toxoids (DTP vaccine).
In 1991, DTaP vaccine was licensed in the US; this utilised a purified version of the pertussis vaccine, claimed to have fewer side effects (DTaP).
In 2005, two new triple vaccines were licensed, intending to make it possible to vaccinate adolescents and adults against pertussis.
Pertussis is not available as a single vaccine, despite many thousands of requests, a need for boosters which does not always coincide with a need for tetanus / diphtheria boosters, and unanswered accusations that combining three potentially toxic substances increases the risks.
What is safer for the population as a whole may be less safe for certain individuals, and there is little work available to help predict the likely victims.
What is the protocol for pertussis
Primary immunisation consists of three doses of a pertussis-containing product with an interval of one month between each dose:
DTaP/IPV/Hib for infants from two months up to ten years of age or to complete a primary course that has been interrupted, allowing an interval of one month between the remaining doses..
The DTaP/IPV vaccine, which contains a lower dose of pertussis antigen, should only be used as a booster in fully primed children.
Children of one to ten years who have completed the primary course plus a reinforcing dose (which includes four doses of diphtheria, tetanus and polio), but have not received four doses of pertussis-containing vaccine, may be offered a dose of combined DTaP/IPV or DTaP/IPV/Hib (if appropriate) to provide some or additional protection against pertussis, preferably allowing an interval of one year from the previous dose.
These children will therefore receive an extra dose of diphtheria, tetanus or polio vaccinesunnecessarily. Such additional doses are likely to produce an acceptable rate of reactions. Acceptable to whom? Are parents told they are being given two unnnecessary vaccinations? This risk could be avoided if a 'single vaccine' were allowed.
Currently immunisation against pertussis is not recommended for children aged ten years or over, and adults.
Who should get vaccinated
Primary immunisation is for infants and children under ten years of age. Repeat vaccinations may be advised for individuals outside that range.
Are there adverse reactions
to the pertussis vaccine?
The original formulation of the vaccine (DTP) became associated with unacceptable levels of brain damage, to the extent that many parents refused to allow vaccination, and many manufacturers were forced to discontinue. The modern acellular pertussis vaccine which was approved in the US in 1992 for use in the combination DTaP vaccine, said to be 'safer'. DTP is still produced, and distributed by the WHO, as it is cheaper.
I have been unable to find any paper that states how much 'safer' the new vaccine is; authorities have been satisfied by the scientific evidence that the risk is 'acceptable'. Interestingly, there is now evidence that resistant starins are developing, reducing the effectiveness of the new vaccine. When introduced, it was said to work in about 95% of cases (DTP prevents almost 100%), again, details of the level of failure do not seem to be available.
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Can pertussis be controlled
Like all airborne infections, pertussis thrives in poor, damp, crowded, overheated environments. Isolation of those affected is essential.
Is there legal protection for
workers and others?
No specific measures apply to pertussis; most countries have health and safety legislation that may apply in some cases.
What can be learned from
Vaccines have proved to be only a partial answer; pressure on parents from governments to take the triple vaccine have led to increasing resistance, particularly as governments have been slow to accept the limitations and problems associated with vaccines, and continue to deny single vaccines to most people; the demonisation of any critic of vaccination policy has proved severely counter-productive, leading to more distrust, and, perhaps perversely, encouraging support for all sorts of weird and unsubstantiated theories. History reliably argues that honesty is the best policy - tell that to a politician at your peril!
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Article written by Andrew Heenan BA (Hons), RGN, RMN