SAFETY OF VACINATIONS By Leungo

Being vaccinated does not necessarily protect everyone against the diseases, however a high percentage of people are protected against the disease. No vaccine is actually 100% safe because safe implies harmless however almost all diseases cause pain, redness or tenderness on the site of injection and some cause more severe side effects.

· Pertussis can cause persistent inconsolable crying; high fever or seizures associated with the fever however these do not result in permanent damage.

· 3 dose of pertussis also known as whooping cough vaccine protects about 85% of children and reduces the severity of the disease in the 15% if they do catch whooping cough

The old pertussis vaccine (whole cell) raised concerns and public perceptions about reactogenicity however this was replaced by the Accellular pertussis vaccine which are less reactogenic

REFERENCES

www.immunise.health.gov.au

Complications and Prevention of Pertussis

PCL 08 - Nobody is Immune
Amber Hartley

Possible Complications of Pertussis

• Convulsions and encephalopathy (These can also be complications of being immunised against pertussis, however they occur in lower frequency than after pertussis itself.)
• Pneumonia
• Atelectasis (reduction or absence of air in part or all of a lung, with resulting loss of lung volume)
• Rectal prolapse
• Inguinal hernia
• Cerebral anoxia, especially in young children
• Bronchiectasis
• dehydration
  

Prevention of Pertussis

• Fairly easily controlled, by isolation of affected individuals
• Immunisation is highly recommended, and usually very effective (90% in those who have 3 doses), but can wear off.
• Prophylactic erythromycin can be given to susceptible infants exposed to the disease
• Experts estimate that non-immunised family members living with someone suffering from pertussis have an 80% chance of contracting it themselves.
• After 3 weeks with pertussis symptoms, the sufferer is much less contagious. Usually, sufferers are considered to be completely non-contagious 6 weeks after first exhibiting pertussis symptoms.
• Asthmatics appear to be more susceptible to pertussis than non-asthmatics.

References

Kumar and Clark (2005), “Clinical Medicine.” 6th edition. Elsevier Saunders Publishing.

http://www.health.gov.au/internet/main/publishing.nsf/Content/health-pubhlth-strateg-communic-factsheets-pertuss.htm

http://www.kidshealth.org/parent/infections/bacterial_viral/whooping_cough.html

http://www.who.int/immunization/topics/wer8004pertussis_Jan_2005.pdf

Pertussis - what is it? plus Aetiology

Pertussis, also known as whooping cough, is a highly contagious disease caused by the bacterium Bordetella pertussis; it derived its name from the characteristic severe hacking cough followed by intake of breath that sounds like 'whoop'; a similar, milder disease is caused by B. parapertussis. Although many medical sources describe the whoop as "high-pitched," this is generally the case with infected babies and children only, not adults.

Characterization

After a two day incubation period, pertussis in infants and young children is characterized initially by mild respiratory infection symptoms such as cough, sneezing, and runny nose (catarrhal stage). After one to two weeks, the cough changes character, with an increase of coughing followed by an inspiratory "whooping" sound (paroxysmal stage). Coughing fits may be followed by vomiting due to the sheer violence of the fit. In severe cases, the vomiting induced by coughing fits can lead to malnutrition and dehydration. The fits that do occur on their own can also be triggered by yawning, stretching, laughing, or yelling. Coughing fits gradually diminish over one to two months during the convalescent stage. Other complications of the disease include pneumonia, encephalitis, pulmonary hypertension, and secondary bacterial superinfection.

Because neither vaccination nor infection confers long-term immunity, infection of adolescents and adults is also common. Most adults and adolescents who become infected with Bordetella pertussis have been vaccinated or infected years previously. When there is residual immunity from previous infection or immunization, symptoms may be milder, such as a prolonged cough without the other classic symptoms of pertussis. Nevertheless, infected adults and adolescents can transmit the bacteria to susceptible individuals. Adults and adolescent family members are the major source of transmission of the bacteria to unimmunized or partially immunized infants, who are at greatest risk of severe complications from pertussis.

management of pertussis

Management of Pertussis:

The disease can be recognised in two different states, catarrhal stage (which is where the patient is most infectious) or paroxysmal stage (which is where the characteristic paroxysms of coughing begin, about a week after catarrhal stage). The stage in which it is diagnosed will affect the method of treatment. If Pertussis is diagnosed in the catarrhal stage then treatment involves erythromycin (a type of antibiotic which slows the growth of and can sometimes kill bacteria), which will decrease the severity of the disease. If the disease is diagnosed in the paroxysmal stage then antibiotics have a very small role in altering the course of the illness. In some cases intravenous pertussis immune globulin therapy has been shown to decrease whooping, to improve oxygen saturation and to stop bradicardic episodes. Membrane oxygenation is widely used in the management of severe pertussis, but it has had limited success, and pertussis severe enough to require its use is in itself a predictor of a poor outcome. Affected individuals should be isolated to prevent the disease spreading.

References: http://www.cmaj.ca/cgi/content/full/172/4/509
http://www.drugs.com/erythromycin.html
Kumar and Clark

(Monica Abadier)

Diagnosis for Pertussis

The diagnosis is usually made on the clinical symptoms of pertussis. The general symptoms include:

• Cold or flu-like symptoms during the first 1-2 weeks: a runny nose, red runny eyes, a slight cough, and a temperature (usually mild)
• Bouts of coughing that become increasingly worse over the next 2-4 weeks. These episodes of coughing can be followed by the sudden effort to breathe, causing the characteristic ‘whoop’ sound of pertussis. Other symptoms during this period include coughing up thick mucus, and vomiting after the coughing attack, which is really more characteristic of pertussis that the ‘whoop’. Patients, especially infants, may turn blue, and afterwards they become very tired and may lose weight.
• The cough and whoop may last for many weeks or even months in the “classic illness”, especially if the patient simultaneously catches a cold or a throat infection

It is much harder to diagnose older children and adults suffering from mild pertussis, as the early symptoms are very similar to an ordinary cold; thus, the doctor may make the diagnosis on the basis of a characteristic history and the symptoms after several days.

The best method for diagnosis would be to take a sample from the back of the nose and culture it – that is, inoculate the sample on a growth medium so that the Bordetella pertussis bacteria responsible for whooping cough can proliferate. However, in some cases, the sample may fail to capture any of the bacteria present. Blood tests can only help if they show a high rise in pertussis antibodies, and this usually can only be seen if a blood test is taken quite early on in the course of the illness, and another blood test taken at the end of the illness. A large enough rise in antibodies must be shown in order to make the diagnosis.

- Maria Nguyen

Sources:

The Family Encyclopedia of Medicine and Health; 1996, The Book Company

http://www.pertussis.com/faq.html

Incidence of pertussis

Since 1993, pertussis has caused the greatest morbidity of any disease preventable by vaccines recommended for children on the National Immunisation Program (NIP) schedule. The highest numbers of pertussis notifications were seen in 2005, with many jurisdictions experiencing an epidemic in that year, followed by 1997 and 2001. Traditionally, hospitalisations in infants aged less than one year have exceeded notifications, indicating that notification rates tend to underestimate pertussis incidence.^3,149 However, in the 2003–2005 period, there were more notifications than hospitalisations in this age group, which may be a reflection of the increased use of PCR to diagnose pertussis in children. In children, hospitalisations coded as whooping cough have been shown to have a high correlation with clinical pertussis.¹⁹ The high proportion (greater than 50%) of hospitalised cases aged less than one year is consistently observed each year and demonstrates the increased morbidity of pertussis in this age group.

Nationally, the highest notification rates up to 1998 inclusive were among children aged less than one year, followed closely by children aged 5–9 and 10–19 years (Figure 26). Since 1999, notification rates have fallen significantly among 5–9 year olds, reflecting the impact of the fifth dose of pertussis vaccine, introduced since 1994 for four year olds because of waning immunity over time.¹⁵⁰ The number of cases reported to be vaccinated for age may be an over-estimate, as the calculation did not include those with an “unknown” status (it is more likely that those recorded as unknown were not vaccinated). Studies show that a primary three-dose course of acellular pertussis vaccine provides 80%–85% protection.⁷⁶

High incidence rates among 10–19 year olds continued to occur in 2003 and 2004. The susceptibility of this cohort is explained by a combination of low historical coverage (whole-cell vaccine safety concerns in the 1980s) and waning immunity (cohort not eligible for school entry booster dose).^150,151 There has been a downward trend in the notification rate for this age group since 2002 and a sharper decline in the rate since 2004. This is likely to reflect the impact of the fifth dose of pertussis vaccine reaching this older cohort and the impact of an adolescent booster vaccine (dTpa), introduced in November 2003. In response to the high incidence rate in adolescents, both New South Wales and Western Australia conducted whole of high school dTpa vaccination programs in 2004. The combined incidence rate for 10–19 year olds in these states decreased from an average of 85.7 per 100,000 population for 1999–2003 to 37.2 per 100,000 population in 2005.¹⁵² As Australian school-based dTpa programs mature and successive cohorts are vaccinated in future years, pertussis in adolescents should become well controlled, as occurred in 5–9 year olds following the introduction of the preschool booster.

In essence, pertussis is now a problem in two broad age groups: infants with the highest notification and hospitalisation rates, particularly those under 6 months of age who are too young to have received two or more doses of DTPa, and people aged 20 years and over, who account for 80% of pertussis notifications. The latter could be partly related to the increased use, especially in adults, of serology as a diagnostic tool (NNDSS data from 2000–2005 shows an increasing percentage of notifications diagnosed by serology (Quinn H et al, NCIRS, unpublished data)). In addition, recommendations for use of pertussis vaccine in adults make it increasingly likely that clinicians will consider pertussis as a potential cause of chronic cough in adults. Hospitalisations in adults are most likely to be related to complications, but could also be falsely inflated because of coding errors. Although severe morbidity and mortality are less likely in adults, increased circulation of pertussis can facilitate transmission to susceptible infants who are too young to be vaccinated.^153–155 The recent increase in the incidence and burden of pertussis notifications in persons aged 60 years and over warrants further investigation. As with parents, grandparents are an important source of pertussis transmission to infants.¹⁵³ It is also unclear whether the morbidity of pertussis in older people is more severe, or if complications are more likely to occur. With this in mind, it is interesting to note that two of eight pertussis deaths in the past five years have been recorded in people aged 60 years and over.³ The current adult pertussis immunisation strategy in Australia is aimed at cocooning infants, by recommending immunisation in adults who are most likely to come into contact with them (such as family members, health care workers and child care workers). It is hoped that, in time, this may have an impact on neonatal cases.

More info on http://www.healthconnect.gov.au/internet/main/publishing.nsf/Content/cda-cdi31suppl.htm~cda-cdi31suppl-3.htm~cda-cdi31suppl-3i.htm

-Satwik