Researchers in the UK have just published a paper in the journal Epidemiology and Infection reporting on the largest series of confirmed cases of Lyme disease in the country. Their findings indicate that not only is the infection much more common than previously thought but that patients’ symptoms can vary considerably, posing something of a dilemma for inexperienced physicians.
The paper, by Dryden and colleagues, details 508 patients who were assessed at a single hospital in the south of England between 1992 and 2012.
The patients tested positive for Lyme disease using the recommended two-tier testing system of ELISA and immunoblot and had a variety of symptoms including:
- Rash (71%)
- Neurological symptoms (16% – 50% of whom had VII cranial nerve palsies)
- Arthropathy (8%)
- Pyrexia (5%)
- Cardiac abnormalities (1%)
- Non-specific symptoms: fatigue, myalgia, cognitive changes (20%).
On average the time between the patient being bitten by a tick and developing clinical symptoms was 15 days, with most then waiting another 14 days before receiving a clinical diagnosis and/or treatment. However, only a third of patients could clearly recall a tick bite preceding the symptoms.
Another group of patients, who were not included in this case study, believed they had Lyme disease based on a probable tick bite but did not test positive on the ELISA or immunoblot and had subjective symptoms that the researchers did not classify as Lyme disease. They stressed the importance of applying an alternative label to the condition suffered by these patients in order to distinguish it from Lyme disease itself. As such, they named this set of symptoms as chronic arthropod-borne neuropathy (CAN)
Lyme Disease Mostly a Summer Phenomenon in the UK
Those patients who did present with Lyme disease tended to have acquired the condition in the summer months and be in either their first decade of life or in their sixties. Some 95% of patients were believed to have become infected with Lyme disease bacteria in the UK, the rest becoming infected while abroad. Standard antibiotic therapy effectively resolved the infection in almost all patients and recurrence of the disease was rare.
This case study noted that between 1992 and 2012 the mean rate of borreliosis in the UK was 9.8/100 000, with the rate increasing each year until levelling off in 2009. The reported national rate during this time was just 1.7/100 000, highlighting a significant disparity that could affect the likelihood of a physician thinking to test for the infection.
As we have noted before at LymeDiseaseGuide.org, there appears to be a difference in the symptoms caused by different subspecies of Borrelia, meaning that those infected in Europe tend to experience more neurological symptoms while those in the US usually report joint pain (arthropathy) more frequently. Where a patient has acquired the infection when travelling this could cause some confusion over the etiology of symptoms and delay diagnosis, illustrating the need for improved physician education and the taking of a detailed medical and travel history for all patients with Lyme disease symptoms in the UK or abroad.
Dryden, M.S., Saeed, K., Ogborn, S., Swales, F. Lyme borreliosis in southern United Kingdom and a case for a new syndrome, chronic arthropod-borne neuropathy. Epidemiol Infect. 2014 May 9:1-12.