19 Jan Leptospirosis (Weil’s Disease)
It’s been a while, but the blog is back and ready to kick off 2021 with a………Well, not really a bang, but more of a pathetic little pffffftt!.
This weeks post is courtesy of Gareth Ward an Advanced Paramedic Practitioner in general practice in the south west and examines Leptospirosis, a relatively rare and easily overlooked disease that requires a high index of suspicion too diagnose.
Leptospirosis is a zoonosis bacterial infection caused by Leptospires, of which there are over 260 different types of serovars (Rahman et al., 2019) . Leptospirosis is caused by an infection of the Leptospires (bacteria) which are thin coiled shaped bacteria which propel themselves in the bloodstream utilizing a flagella.
The leptospires are excreted by animal urine (mainly rats) and contaminate the human host through broken skin or the conjunctiva. As the leptospires affect different organs, this will depend on the symptoms shown. The invasiveness mechanism remains poorly understood (Ge et al., 2020) .
The epidemiology shows that it is more frequently seen in the tropics (up to ten times) due to poor sewer management. However, it was still prevalent with 91 cases in the U.K. last year (Public Health England, 2020) . Only 10% of patients will progress to Weil’s Disease (Sagar, Patel and Rai, 2019) .
The incubation period is generally 7–21 days (maybe 2–30 days), but reiterating the mechanism remains poorly misunderstood. Bacteria enter the hosts skin via broken skin and gain entry less commonly through the mucosa or conjunctiva in the eyes. Once the bacteria is in the host, the innate immune system initiates, causing patients to feel myalgia, headache and fever. Which often can be misinterpreted as a viral illness which is why occupational history is of importance. For a small sample of patients, this will progress into Weil’s disease due to the bacteria spreading amongst different part of the body. Leptopsires colonize in the kidneys, likely causing an acute kidney injury (AKI). There is a well-known triad of Jaundice, AKI and haemorrhage (secondary to thrombocytopenia) (Lau et al., 2018) .
Occupations where there may be a risk of occupationally acquired Weil’s disease include:
workers in outdoor leisure industries, particularly if in contact with water;
sewage and wastewater workers;
construction/demolition/building renovation workers – where there are rodents or stagnant water;
farmworkers; and pest control workers
Health and Safety Executive (N.D)
Diagnosis & Investigation
Due to vague symptoms that the patient will present with, standard investigatory blood should be undertaken. Consisting of full blood count, CRP, renal function, liver function tests(if systemically unwell or any clinical concern discuss with medics on call). Further tests can be carried out as below but involve a high turn around time to patient follow up is pivotal with robust safety netting advice.
Most patients won’t require any medications and symptoms will resolve. A small percentage of patients mentioned above may require hospital admission due to secondary complications requiring hospital treatment such as an AKI. Whilst awaiting antibody results, it’s imperative that patients are followed up and given strict safety netting advice.
Ge, Y.-M., Sun, A.-H., Ojcius, D.M., Li, S.-J., Hu, W.-L., Lin, X. and Yan, J. (2020) M16-Type Metallopeptidases Are Involved in Virulence for Invasiveness and Diffusion of Leptospira interrogans and Transmission of Leptospirosis. The Journal of Infectious Diseases [online]. 222 (6), pp. 1008–1020. Available from: https://academic.oup.com/jid/article/222/6/1008/5818523doi:10.1093/infdis/jiaa176 [Accessed 15 January 2021].
Health and Safety Executive (no date) Leptospirosis (Weil’s Disease and Hardjo) Background Information [online]. Available from: https://www.google.com/url?client=internal-element-cse&cx=015848178315289032903:hqkynptgd1o&q=https://www.hse.gov.uk/agriculture/zoonoses-data-sheets/leptospirosis.pdf&sa=U&ved=2ahUKEwjszsHGrqjuAhWgR0EAHbSSBowQFjABegQICRAB&usg=AOvVaw0rAVuWG4m9LSKq5ZczH8Tm [Accessed 19 January 2021].
Lau, C.L., Townell, N., Stephenson, E., van den Berg, D. and Craig, S.B. (2018) Leptospirosis: An important zoonosis acquired through work, play and travel. Australian Journal of General Practice [online]. 47 (3), pp. 105–110. Available from: https://www1.racgp.org.au/ajgp/2018/march/leptospirosisdoi:10.31128/AFP-07-17-4286.
Public Health England (2020) Common animal-associated infections quarterly reports: 2019 – GOV.UK. Available from: https://www.gov.uk/government/publications/common-animal-associated-infections-quarterly-reports-2019 [Accessed 15 January 2021].
Rahman, A., Rachman, A., Malaysia, K., Yaacob Latif, J., Tun Razak, B. and Lumpur Malaysia, K. (2019) Evaluation of IgM LAT and IgM ELISA as compared to microscopic agglutination test (MAT) for early diagnosis of Leptospira sp Tropical Biomedicine 36 (4).
Sagar, P., Patel, H. and Rai, S. (2019) Clinical and Laboratory Evaluation of Patients with Fever with Thrombocytopenia. 07 . Available from: https://dx.doi.org/10.18535/jmscr/v7i11.40doi:10.18535/jmscr/v7i11.40 [Accessed 15 January 2021].