Leptospirosis in humans

This text from HM Government 2022



Data for leptospirosis was obtained from the Rare and Imported Pathogens Laboratory (RIPL, UKHSA Porton Down). As of 1 August 2020 a laboratory-confirmed case of leptospirosis is defined by a positive 16S rRNA PCR result only. An IgM enzyme-linked immunoabsorbent assay (EIA) continues to be performed on all samples of suspected leptospirosis cases. A case with a positive leptospirosis IgM result will usually be treated clinically on the basis of this result, even in the absence of a positive PCR result. A case with a positive IgM but without a confirmatory PCR result is therefore reported as a probable case for surveillance purposes.

There were 25 confirmed cases of leptospirosis reported in the third quarter of 2022, compared to 16 cases reported in the same quarter of 2021. There were 36 probable cases reported in the third quarter of 2022, compared to 15 in the same quarter of 2021. Figure 2 shows the number of confirmed cases reported by quarter over the past 5 years (2018 to 2022).

Figure 1. Laboratory confirmed and probable cases of leptospirosis by quarter, Q1 2018 to Q3 2022

In the third quarter of 2022, 20 confirmed cases (20 out of 25, 80%) were male (aged 17 to 75 years) and 5 cases (5 out of 25, 20%) were female (aged 48 to 51). Cases were reported in the South East (8), London (5), the East of England (4), the South West (3), Yorkshire and Humber (2), the North West (1), the West Midlands (1) and the East Midlands (1). No cases were reported in Wales.

Of the confirmed cases, 16 (64%) reported recent travel abroad. Of these, 6 cases had visited southeast Asia, 6 cases had visited central America, one case had visited South America, 2 cases had visited southern Europe and one case had visited western Europe.

Of the 25 confirmed cases, 9 reported potential exposures (some cases reported more than one exposure):