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Measles: top of the spots

Measles is back in the news again with outbreaks reported by the Health Protection Agency in areas such as Hackney, Surrey and Sussex.(1) Wendy Cunningham explores the reasons behind these outbreaks and advises on how healthcare professionals can recognise and treat the disease, and work together with parents to help get measles back under control again

Wendy Cunningham
BSc Advanced Nurse Practitioner (Primary Care)
Nurse Practitioner Mandeville and Elmhurst Surgeries Aylesbury
Buckinghamshire
Senior Lecturer and
Mentor
BSc Nurse Practitioner Programme
London South Bank University

Measles is a highly contagious acute viral illness that is caused by the rubeola virus and is spread by aerosols of infected nasopharyngeal secretions (droplets). Once a person becomes infected, the virus lives in the mucosa of the nose and throat later multiplying in the lungs.(2) It can live on inanimate surfaces for up to two hours following contact with infected secretions, and remains active and contagious during this time. Measles carries a high morbidity and mortality rate and is rarely subclinical. While any age group can be affected, it is mainly seen in the under-fives. It is a notifiable disease and should be reported to the HPA according to local and national guidelines.

The global picture
The World Health Organization has set goals to globally eradicate measles by 2010, but in order for this to be achieved, 95% of the world's population needs to be immunised. By definition, elimination requires less than one case per million in a given region and eradication necessitates worldwide elimination.(3)
Measles is among the top five infectious disease killers worldwide, with 30 million cases each year accounting for a million deaths per annum, and a 5-15% mortality rate in Africa alone.(4) There is no difference in strain from the measles we see in the Third World to that affecting the European population and there are no animal reservoirs.

Prevention
Prevention is by measles mumps and rubella (MMR) vaccination with a primary combined dose given at 13 months, which is said to confer 90-95% immunity. A further booster dose is recommended for preschool children at three to five-years-of-age. This is necessary as 5% of recipients do not acquire immunity following the primary dose. Of that remaining 5% who are not immune, 95% will respond following the booster, ensuring almost 100% immunity levels are achieved.5 Unfortunately there is no way of predicting which children will fall within the 5% category so it is recommended that all children receive the booster dose. For those children who have achieved immunity after the primary dose, the booster does no harm and merely boosts immunity.
 
History
Notification of measles in England and Wales began in 1940 and a measles vaccination was introduced in 1968. This resulted in a substantial reduction in measles transmission (see Figure 1).
Seroprevalence studies confirmed that a higher proportion of school-age children were susceptible to measles in 1991 than in 1986/7, and a major resurgence of measles was predicted.(5) Small outbreaks occurred in 1993 in England and Wales, and Scotland saw an epidemic in 1993-4 when 138 teenagers were admitted to hospital. In order to prevent an epidemic in the UK, a large vaccination campaign was implemented in 1994 for 5-16-year-olds and eight million children were immunised against measles and rubella, as there were insufficient stocks of the full MMR vaccine. This resulted in a sevenfold reduction in the susceptibility to measles rates in the target population and endemic transmission was interrupted. To maintain control after this campaign, a two-dose MMR schedule was introduced in 1996.

[[nip43_fig1_31]]

Media scares
Until 2006, the last confirmed death from measles was in 1992 in an unimmunised immunocompromised 13-year-old boy. Between 1995 and 2003 there were 12 deaths in England and Wales. There were 739 confirmed cases of measles in the UK in 2006.(6)
Publicity surrounding a speculative and highly contentious report published in The Lancet in 1998 postulating a link between the MMR vaccine and autism and bowel disease was thought to have had an impact on the reduction of vaccination uptake.(6) Media scares further raised parental anxiety resulting in some parents refusing the vaccine altogether while others opting for single-dose vaccines.
The Department of Health subsequently funded studies to investigate the suggestions, but scientists found no associated link to autism and bowel disease. Numerous studies from The Committee on Safety of Medicines, the Medical Research Council and the Cochrane Collaboration have also dismissed these theories and experts have repeatedly stressed that public concern about the safety of the MMR vaccination has no foundation. Public health experts are hoping to bring an end to this controversy and have highlighted that autism is often first diagnosed in children around the same age that MMR vaccination is undertaken, and that the increased incidence of autism preceded use of MMR.
 As with any vaccine scare the perpetual cycle is seen. Vaccination uptake is reduced, the disease manifests, so vaccine uptake increases again, with resulting disease rate reduction. However, while all this is happening, many people become infected and risk serious complications with some cases proving fatal. A classic example is the pertussis vaccination scare in the late 1970s.

Signs and symptoms of measles
The pre-eruptive and catarrhal stage
Measles initially presents with cold symptoms such as rhinorrhoea, conjunctival suffusion (runny eyes), photophobia and mild-to-severe temperature, which may peak at >40.5oC. Greyish white irregular spots surrounded by an erythematous base known as Koplik's spots can be found on the buccal mucosa opposite the second molars and are diagnostic at this stage. They appear like salt grains on a red base one to two days before the rash appears, and last for two to three days. Other symptoms such as tiredness, irritability and lack of energy accompany generalised aches and pains, poor appetite and a dry cough. This is sometimes referred to as the prodromal (running before) stage.

The eruptive or exanthematous stage
On days three to four following initial symptoms a maculopapular reddish brown rash appears and
classically starts behind the ears, on the forehead and neck spreading to the trunk and limbs in a downward pattern. The rash eventually becomes confluent (joined up) and lasts for up to 10 days, but can leave brown postinflammatory staining and desquamation, which may take up to eight weeks to fade completely.
It should be noted that measles can occur without a rash in immunocompromised patients weeks or months after exposure.

Diagnosis
Diagnosis is made from the typical clinical picture of the prodromal pre-eruptive and exanthematous stages and strongly suggestive features include:

  • Rash for at least three days.
  • Fever for at least one day.
  • At least one of the following: cough, coryza or conjunctivitis.

Confirmation is by positive IgM-specific saliva or serum analysis. These must be taken within six weeks from onset of symptoms.
Management
Treatment is based on symptom control and the treatment of complications. Antipyrexial measures such as paracetamol or ibuprofen, light cotton clothing and ensuring adequate fluids to avoid dehydration are in accordance with NICE guidelines.(7) Encourage rest. Dimming the lights relieves eye discomfort if photophobia is present. Ensure the eyes are kept clean to remove discharge and prevent crusting. Humidity may help reduce cough. Children should be reviewed around day three to assess for pneumonia. Antibiotics are indicated only for secondary infection. The HPA recommends that children stay off school until five days from onset of rash, but this may need to be extended dependent on the clinical condition of the child.
Measles has an 8-14-day incubation period and infectivity is from two to four days before and five days following the appearance of rash. Reinfection is rare. 

Complications
Complications can be mild, such as otitis media, laryngitis and conjunctivitis, but may be severe as in bronchopneumonia and more rarely encephalitis, meningitis, hepatitis and pericarditis, which can prove fatal (see Table 1). Optic neuritis can result in squint (strabismus) due to optic nerve damage. Those who are
malnourished or immunocompromised are at increased risk of complications.
Subacute sclerosing panencephalitis can occur several years after contracting measles and is fatal, but is very rare. Maternal measles is not teratogenic but can cause miscarriage.

[[nip43_table1_32]]

Combined MMR vaccine
The MMR vaccine was introduced in 1988 as a combined vaccine and is generally well tolerated (See Table 2 for adverse reactions). It is a live vaccine containing
attenuated (modified) organisms given by intramuscular injection as Priorix (GlaxoSmithKline) or M-M-R II (Sanofi Pasteur) in the deltoid or anterolateral thigh. Separate limbs should be used but if another vaccination is given in the same limb, the sites should be 2.5 cm apart. It may be given by deep subcutaneous injection in patients with bleeding disorders.
Live vaccines should be given either at the same time as other live vaccines or four weeks apart. If given simultaneously, each vaccine will begin to replicate an appropriate immune response. Interferon is produced and should a further live vaccine be given during this response time, the interferon may prevent replication of the second vaccine. If there is a history of true anaphylaxis to eggs then paediatric opinion should be sought.
MMR is contraindicated in pregnancy, untreated malignant disease and in those who have had a severe reaction to previous immunisation or are allergic to the excipients neomycin, kanamycin or gelatin. It is fairly well tolerated, but side-effects that mimic a mild measles infection with presentation of a rash the first week after immunisation and parotid swelling may be seen in 1:50 at around the third week, lasting a few days. Anaphylaxis remains a risk as with any immunisations (see Table 2).
If a child is exposed to measles after six months of age and before primary vaccination, they should be given the MMR. Babies under six months of age are thought to have acquired immunity from their mothers.
If a child has received MMR before 12 months of age due to travel or outbreaks of measles, this dose should be discounted and a further two doses given at the recommended times.

[[nip43_table2_32]]

Human normal immunoglobulin
Human normal immunoglobulin (HNIG) may be given within five days of exposure and effectively aborts an attack of measles. HNIG is derived from plasma sourced outside the UK due to the risk of variant Creutzfeldt-Jakob disease and is screened for hepatitis C and B, and HIV. A person may be given the vaccination within three days following exposure to measles and most will become immune. Ninety percent of members of the same household who have been in contact with measles will develop it if they are not immune.

Single-dose vaccines
Single-dose vaccines are not advocated by the Department of Health and HPA, and are only available privately. They are not licensed for use in the UK. Private clinics are self-regulating and there have been reports of quality assurance problems such as poor maintenance of the cold chain and reconstitution
inaccuracies. There have been reports of falsified blood tests to prove seroconversion and ongoing legal cases are outstanding.
There are increased risks associated with single-dose schedules. Each vaccination carries a certain risk of anaphylaxis, and recipients are exposed to a six-fold risk with single doses as opposed to two with the combined. They are also at risk of acquiring the actual diseases while awaiting completion of the course.

What has been done?

  • Some areas in the UK have developed innovative schemes to make information more accessible and convenient, such as the ''spotty bus'' in Hackney, which brings immunisation and education materials to the public.
  • WHO and UNICEF are undertaking large immunisation programmes in an attempt to combat the disease in the Third World.
  • Early diagnosis and treatment coupled with vaccination of contacts should be upheld along with vigilance in reporting cases.
  • Healthcare professionals should take every opportunity to ensure that patients and parents have all the evidence-based information to help them make informed decisions.
  • Opportunistic vaccinations should be offered and consideration of flexible clinic times made available to improve accessibility for working parents.
  • Healthcare workers should have received the two doses of MMR or have a positive antibody test for measles and rubella to prevent spread to their patients and to protect them from the disease.

Conclusion
While we must remain open-minded to new ideas and theories, we must ensure that our practice is based on sound evidence-based medicine to safeguard patients and ensure that accurate information is relayed to them.
With unrelenting efforts to take every opportunity to ensure that vaccination programmes are accessible, safe and encouraged, we can work collaboratively towards WHO targets of global eradication of measles.

References

  1. Health Protection Agency. Measles. Available from: http://www.hpa.org.uk
  2. Kumar P, Clark M. Clinical medicine. 5th ed. Edinburgh: WB Saunders; 2002.
  3. World Health Organization. Measles. Available from: http://www.who.int/topics/measles/en
  4. University of Leeds. Measles, mumps and rubella. Available from: http://www.dentistry.leeds.ac.uk/oralpath/viruses/viral%20infections/MMR...
  5. Department of Health. Immunisation against infectious diseases. The Green Book. London: DH; 2006. Available from: http://www.dh.gov.uk/en/publichealth/healthprotection/immunisation/green...
  6. Wakefield AJ, Murch SH, Anthony A, et al. Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children. Lancet 1998;351:637-41.
  7. National Institute for Health and Clinical Excellence. Feverish illness in children: assessment and initial management in children younger than five years. Clinical Guideline 47. London: NICE; 2007.


Resources

Dermnet
W: www.dermnet.org

UK Clinical Virology Network
W: www.clinical-virology.org

Clinical Knowledge Summaries:
clinical topics
W: www.cks.library.nhs.uk/clinical_topics
 
Bandolier
W: www.ebandolier.com

Your comments: (Terms and conditions apply)

"Great article. However, the issue of anaphylaxis to eggs was disproved by Gold in 2000 (see Green Book). He did a big study in Australia and found that the true allergen was gelatine, which you do allude to." - Kirsty Armstrong, London