What does the new model salaried contract mean for GPs?
Mumps is back and GPs are in the frontline Dr David Baxter takes a look at the outbreak and the GP's role
Behind the headlines
·Some 1,352 cases of mumps were reported between April and June 2004 the highest in the seven years since records began
·MMR uptake fell to
80 per cent across the UK in 2003/4
·Uptake of first MMR vaccine by age five also fell by 0.5 per cent and coverage of the preschool booster plunged by 0.6 per cent in the last quarter
Two weeks ago Pulse asked me for an article on the current situation regarding mumps.
Just as I began to write it a colleague rang to complain of an acute painful swelling in the neck associated with facial swelling and fever: further questioning identified that the swelling was bilateral, tender and located in the region of the parotid gland.
The differential diagnosis is discussed later, but mumps immediately sprang to mind as the most likely cause given the substantial increase in cases and because the individual was a young adult who hadn't received two mumps-containing vaccines.
The country-wide outbreak started several years ago and so far there have been 3,756 confirmed cases in the first nine months of 2004 compared with just over 372 in 1999 the cause is in part due to how the MMR programme was implemented in the 1990s and in part to the ongoing concern about adverse vaccine events and its knock-on effect on MMR uptake.
MMR vaccine was introduced to the USA in the early 1970s in the UK we used separate measles and rubella vaccines for females and measles for males until 1988 when both programmes were replaced with the combined MMR.
Initially given as a one-dose programme, the primary vaccine failure rates (estimated at 1 per cent for rubella, 6 per cent for measles and 12 per cent for mumps) demanded a two-dose schedule which was subsequently introduced in 1996: however, lack of available mumps vaccine meant that a number of children only received the MR (measles and rubella) vaccine.
Concern over adverse events was caused by Dr Andrew Wakefield's 1988 study of 10 autistic children. Waves of publicity given to this and other studies caused uptake to decline.
Infectivity and transmission
The numbers of susceptible children, adolescents and young adults has now become large enough for mumps to transmit. Such spread, which is by respiratory droplets and direct contact, takes place from a couple of days before onset of the parotitis and lasts about seven days. Maximum infectivity is from two days before to four days after onset of parotitis. While not as easily spread as influenza or measles, about 90 per cent of people had mumps infection by the age of 20 prior to mass immunisation.
Mumps generally affects the parotid glands but can involve the submandibular and sublingual glands.
The differential diagnosis of infective parotitis includes parainfluenza (types 1 and 3), influenza, coxsackie A and B, cytomegalovirus, enteric cytopathic human orphan and lymphocytic choriomeningitis viruses: the most common bacterial cause is Staphylococcus aureus although this is generally unilateral.
Other causes of parotid swelling include salivary calculus, cervical adenitis, neoplasia, Mikulicz syndrome and drug-induced parotid swelling.
The diagnosis is usually made on clinical grounds: mumps specific IgM can be detected by a saliva test kit available from your local health protection unit (HPU).
A viral swab throat sample is also a good idea. Treatment for uncomplicated cases is generally symptomatic and supportive. Mumps is notifiable to the local 'proper officer' using the standard notification form.
'Recurrent mumps' is explainable on the basis of infection with any of the different strains of mumps virus or other viral pathogens can cause bilateral parotitis.
The Health Protection Agency in collaboration with local HPUs and PCTs has organised a number of vaccination programmes in schools and universities where outbreaks have been reported: in addition a number of school nurse services now offer MMR to secondary school children as part of a regular programme.
Endemic mumps is of concern because it isn't simply a minor viral illness causing salivary gland swelling, headache and fever which resolves within a week without requiring anything other than supportive care.
Infection with wild mumps is systemic from the start and involvement of other organs including the testes, ovaries, pancreas and eyes is common: furthermore, because it is a neurotropic virus, complications include meningitis, encephalitis, myelitis, polyneuritis and cranial neuritis1-3.
These adverse outcomes are more likely if infection is acquired as an adult: furthermore such complications can also occur in the 30 per cent of cases without salivary gland involvement the so-
called 'subclinical group'.
Orchitis is present in up to a third of postpubertal males it can reportedly cause sterility if bilateral.
Testicular swelling may be present at the onset of illness or can develop up to 10 days later: one in 20 females can develop oophoritis.
Pancreatitis should be suspected in an individual with parotitis complaining of abdominal pain.
Estimates of the frequency of neurological complications vary. In the USA meningitis reportedly occurs in 10 per cent of clinical cases and encephalitis in 2.6 per 1,000 cases since the latter has a 2 per cent mortality, meningoencephalitis is a potentially devastating complication.
To the extent that immunisation programmes are delivered through primary care, GPs are key to ensuring that vaccine uptake rates increase to the 95 per cent required to prevent endemic disease transmission. Clearly, however, national and local support is required to address the adverse publicity specifically associated with MMR.
In terms of managing this specific outbreak you can also assist by providing opportunistic MMR immunisations. Last week I wrote to the GPs with whom I work recommending that any adolescents and young adults registered with them who come to the practice requesting MMR be given this if unprotected.
This was probably the fifth or sixth such letter written over the past three years. Such an approach will decrease the numbers of susceptibles and should be accommodated in nGMS as a payment as part of outbreak disease management.
1988 MMR vaccine introduced for all babies over one year
1996 Second MMR dose introduced for children aged three to five years of age. Catch-up programme launched. Dose introduced for all children born after
Jan 1 1990 who have not had two doses
1998 Wakefield study suggesting link between MMR and autism published
2003/4 MMR uptake falls to 80 per cent across UK
2004 Quarterly cases of mumps rise to 1,352 - the highest for seven years
Some complications of mumps
·Aseptic meningitis in 15 per cent (usually without further complications)
·Orchitis (usually unilateral) in up to 20 per cent of post-pubertal males; sterility seldom occurs
·Oophoritis in 5 per cent of post-pubertal females; sterility seldom occurs
·Profound deafness occurring in one ear 1:15,000 cases
·Encephalitis between 1:400 to 1:6000 cases, case fatality rate for mumps encephalitis is 1.4 per cent
·Pancreatitis, neuritis, arthritis, mastitis, nephritis, thyroiditis and pericarditis may also occur
·Although no evidence of fetal abnormalities, mumps in the first trimester of pregnancy may increase the rate of spontaneous abortion
·Mumps vaccine is one of the components of MMR vaccine; the introduction of MMR vaccine in 1988 effectively halted the three-yearly cycles of mumps epidemics
Source: Health Protection Agency
1 CDC. (1984) Mumps surveillance report. January 1977-December 1982. Atlanta, GA: US Department
of Health and Human Services, Public Health Service
2 Philip RN et al (1959). Observations on mumps epidemic in a 'virgin' population. American Journal
of Hygiene, 69, 91-111
3 Hayden GF et al (1978). Current status of mumps
and mumps vaccine in the United States. Pediatrics,
David Baxter is consultant in communicable disease control at Greater Manchester Health Protection Unit