Abstract:
BACKGROUND
The largest outbreak of sporotrichosis occurred between 1938 and 1947 in the gold mines
of Witwatersrand in South Africa. Here, we describe an outbreak of lymphocutaneous sporotrichosis
that was investigated in a South African gold mine in 2011.
METHODOLOGY
Employees working at a reopened section of the mine were recruited for a descriptive
cross-sectional study. Informed consent was sought for interview, clinical examination and
medical record review. Specimens were collected from participants with active or partiallyhealed
lymphocutaneous lesions. Environmental samples were collected from underground
mine levels. Sporothrix isolates were identified by sequencing of the internal transcribed
spacer region of the ribosomal gene and the nuclear calmodulin gene.
PRINCIPAL FINDINGS
Of 87 male miners, 81 (93%) were interviewed and examined, of whom 29 (36%) had skin
lesions; specimens were collected from 17 (59%). Sporotrichosis was laboratory-confirmed
among 10 patients and seven had clinically-compatible lesions. Of 42miners with known HIV
status, 11 (26%) were HIV-infected. No cases of disseminated disease were detected. Participants
with 3 years’ mining experience had a four times greater odds of developing sporotrichosis
than those who had been employed for >3 years (adjusted OR 4.0, 95%CI 1.2–13.1). Isolates from 8 patients were identified as Sporothrix schenckii sensu stricto by calmodulin
gene sequencing while environmental isolates were identified as Sporothrix mexicana.
CONCLUSIONS/SIGNIFICANCE
S. schenckii sensu stricto was identified as the causative pathogen. Although genetically
distinct species were isolated from clinical and environmental sources, it is likely that the source was contaminated soil and untreated wood underground. No cases occurred following
recommendations to close sections of the mine, treat timber and encourage consistent
use of personal protective equipment. Sporotrichosis is a potentially re-emerging disease
where traditional, rather than heavily mechanised, mining techniques are used. Surveillance
should be instituted at sentinel locations.
