This discussion is based on Question 1 of the Sample Calculation Paper, December 2018, from the GPhC
The past few months have seen a rising crescendo of news articles highlighting a growing global measles epidemic and crisis. The following list is drawn from just the BBC alone.
- 20 August 2018: Measles cases reach record high in Europe
- 15 February 2019: Measles is evil. We have to vaccinate
- 25 March 2019: The measles has made my life
- 27 March 2019: US County declares measles outbreak emergency.
- 27 March 2019: Explaining the US measles outbreak
- 5 April 2019: Measles: How a preventable disease returned from the past
- 9 April 2019: New York measles emergency declared in Brooklyn
- 24 April 2019: Measles: Greater Manchester outbreak rises to 47 cases
- 26 April 2019: Measles outbreak: Trump tells Americans to “get their shots”
The sad reality is that this is a crisis that could largely have been prevented in the developed world. UNICEF reports that, globally, over the past 8 years an average of 21.1 million children have missed out on essential measles vaccines each year, giving a total of approximately 169 million unvaccinated children in that time period alone. In high-income countries, the statistics make for some sobering reading. The raw data over this time period is shown on the following table, courtesy of UNICEF.
The United States is significantly over-represented, as the equivalent doughnut chart shows below.
The reasons for failures to achieve required measles vaccination rates are varied. Measles has had a hard time because of the influence of disproven scare stories linking the MMR vaccine with autism. This misinformation has led to increasing fear or skepticism about the vaccine.
In low and middle-income countries, on the other hand, the causes are related to poor governance, poor health systems, complacency, logistic and economic challenges. Data from 2017 alone show that the countries that contributed the most were Nigeria, India, Pakistan, Indonesia and Ethiopia.
UNICEF highlights that two doses of the measles vaccine are essential to protect children from the disease. However, the global coverage of the first dose of the measles vaccine was reported at 85 per cent in 2017, a figure that has remained relatively constant over the last decade despite population growth. Global coverage for the second dose is much lower, at 67 per cent. The World Health Organization recommends a threshold of 95 per cent immunization coverage to achieve so-called ‘herd immunity’.
The BBC has a useful video that discusses vaccines, particularly the measles vaccine, in some detail. It is helpful to watch and is added below for reader convenience.
The BBC has reported exciting developments in the treatment of some of the symptoms of Parkinson’s disease. Researchers in Canada have managed to develop a new treatment that helps restore the ability to walk in affected patients through an implant that provides electrical stimulation in the spine. The following video, provided courtesy of the BBC, provides further details.
The British National Formulary (BNF) defines Parkinson’s disease as a progressive neurodegenerative condition resulting from the death of dopaminergic cells of the substantia nigra in the brain.
Motor-symptoms may include hypokinesia (decreased bodily movement), bradykinesia (slowness of movement), rigidity (stiffness), rest tremor, and postural instability. Non-motor symptoms include dementia, depression, sleep disturbances, bladder and bowel dysfunction, speech and language changes, swallowing problems and weight loss. Patients with suspected Parkinson’s disease should be referred to a specialist and reviewed every 6 to 12 months.
Both the BNF and the National Institute for Health and Care Excellence (NICE) highlight the need for both pharmacological and non-drug treatment options for the various symptoms. In respect of non-drug treatment, patients should be offered physiotherapy if balance or motor function problems are present, speech and language therapy if they develop communication, swallowing or saliva problems, and occupational therapy if they experience difficulties with their daily activities. Dietitian referral should be considered.
Drug treatment has centred on negating the effects of the loss of dopamine through replacing dopamine (via levodopa), using dopamine agonists or using a range of drugs that offset the negative effects of dopamine loss. The medical challenge is being able to attain the fine balance that mimics normal brain and motor function without the development of unacceptable side effects from the drugs themselves.
NICE highlights that initial drug treatment should be subject to a consideration of the relative benefits and harms of the treatment options, using the following comparative chart for reference:
The guidance highlights that in early stages of Parkinson’s disease, patients whose motor symptoms decrease their quality of life should be offered levodopa combined with carbidopa (co-careldopa) or benserazide (co-beneldopa), which help prevent the peripheral metabolism of levodopa. Parkinson’s disease patients whose motor symptoms do not affect their quality of life, could be prescribed a choice of levodopa, non-ergot-derived dopamine-receptor agonists (pramipexole, ropinirole or rotigotine) or monoamine-oxidase-B inhibitors (rasagiline or selegiline hydrochloride).
The NICE guidance goes on to provide more guidance on what to do in the event that a patient develops motor fluctuations, uncoordinated movements or simply that the medicines stop being as effective due to progression of the disease.
The news of the development of new treatment via electrical stimulation therefore offers promise as an option with comparatively low side effects, particularly where traditional approaches have reached their limits. It also comes on the back of recent findings that Parkinson’s disease may start in the gut, a promising field of research that may yet yield other avenues towards treating, preventing or reversing this debilitating condition.