Lyme disease in England and Wales more common in older white women, study finds

Patients with Lyme disease in England and Wales hospitals appear to be predominantly white, female and living in areas of low deprivation, according to a new study by the University of Liverpool and Public Health England.

The study, which examined data on 2,361 hospital patients collected between 1998 and 2015, also found an increase in Lyme disease incidence over time, with the number of new cases peaking in August each year and higher rates in central southern and western England. The findings, published today in BMC Public Health, may inform and help target health promotion messages.

Lead author Dr John Tulloch, who is based at the NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, said: “In the United Kingdom information relating to infected Lyme disease patients’ characteristics, where they live and how they are managed within the National Health Service is not fully understood. Through our analysis of NHS hospital data we were able to identify demographic information about Lyme disease patients accessing hospitals for management and treatment and, for the first time, start to describe how they progress through the healthcare system.”

The authors identified 2,259 Lyme disease patients within anonymised health records in England and 102 patients within records in Wales, respectively. Out of all identified cases, 60.1% were women or girls, with peaks of new cases at the ages between six and ten, and 61 and 65 years. Out of the 1,877 patients for whom ethnicity information was recorded 96% self-identified as white.

Dr Tulloch said: “These data display a predominance of female cases of certain age groups, most of whom identify as white. The reasons for this are hard to explain, but could be related to differences in health seeking behaviour between women and men and an increased exposure to tick habitats due to leisure activities in children and older people, as opposed to occupational exposure in younger adults. The apparent association between ethnicity and Lyme disease is most likely due to sociocultural and behavioural reasons, for example living in areas that are more likely to see a higher abundance of disease-transmitting ticks.”

Analysing the data over time, the authors found that the number of new cases rose from 0.08 per 100,000 people in 1998 to 0.53 cases per 100,000 people in 2015. The exact cause for the increase in Lyme disease incidence remains unclear, but may be the result of various factors, such as increased awareness by the public and/or hospital clinicians, increase in referrals by clinicians in primary care, or a true increase in incidence within England and Wales, according to the authors.

Dr Tulloch said: “Almost all parts of England and Wales reported Lyme disease cases attending hospitals with clear hotspots of disease in central southern England. This highlights that while Lyme disease poses a risk across both countries, for the majority of people the risk is likely to be very low.”

In a recent complementary study, published in BMJ Open, the researchers also looked at the demographics of 3986 laboratory-confirmed Lyme disease cases in England and Wales from 2013–2016 and found many similar findings. The incidence of laboratory-confirmed Lyme disease rose significantly from 1.62 cases per 100 000 in 2013 to 1.95 cases per 100 000 in 2016, with a significant clustering of cases located in southern England. The results also suggested that Lyme disease patients originate from areas with higher socioeconomic status and disproportionately in rural areas.

Dr Tulloch added: “Being aware of the signs and symptoms of Lyme disease is important so that patients can receive early diagnosis and treatment from their family doctor. Symptoms typically develop up to three weeks after being bitten by a tick and include a spreading circular red rash or flu-like symptoms.”

Research reference:

Characteristics and patient pathways of Lyme disease patients: a retrospective analysis of hospital episode data in England and Wales (1998–2015), BMC Public Health, doi.org/10.1186/s12889-019-7245-8

The demographics and geographic distribution of laboratory-confirmed Lyme disease cases in England and Wales (2013–2016): an ecological study, BMJ Open, doi:10.1136/bmjopen-2018-028064