An outbreak of lymphocutaneous sporotrichosis among mine-workers in South Africa

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.http://www.plosntds.orgam201

Epidemiologic Investigations into Outbreaks of Rift Valley Fever in Humans, South Africa, 2008–2011

Rift Valley fever (RVF) is an emerging zoonosis posing a public health threat to humans in Africa. During sporadic RVF outbreaks in 2008–2009 and widespread epidemics in 2010–2011, 302 laboratory-confirmed human infections, including 25 deaths (case-fatality rate, 8%) were identified. Incidence peaked in late summer to early autumn each year, which coincided with incidence rate patterns in livestock. Most case-patients were adults (median age 43 years), men (262; 87%), who worked in farming, animal health or meat-related industries (83%). Most case-patients reported direct contact with animal tissues, blood, or other body fluids before onset of illness (89%); mosquitoes likely played a limited role in transmission of disease to humans. Close partnership with animal health and agriculture sectors allowed early recognition of human cases and appropriate preventive health messaging

Validation of a Pan-fungal polymerase chain reaction (PCR) assay for the detection and identification of medically important fungi in a diagnostic laboratory

The laboratory diagnosis of fungal infection is complicated, based on the microscopic detection, culture isolation, and detection of serological response. In recent years, there has been an increase in the utilization of molecular diagnostic techniques for the detection and accurate identification of fungal pathogens. This was a laboratory accuracy study evaluating the performance of a selected pan-fungal PCR using 70 previously identified reference fungal isolates. The DNA yield and purity of three different DNA extraction methods was assessed, using 6 representative fungal isolates. The ZR Fungal/Bacterial DNA MicroPrep™ produced a median concentration of 17.28 ng/μl,which was significantly higher (p value = 0.0079) than the MagNA pure LC DNA Isolation Kit III and QIAamp DNA Mini Kit, which produced median yields of 11.08ng/μl and 3.54 ng/μl, respectively. The selected pan-fungal PCR was optimized PCR and successfully performed on 62 of the 70 reference isolates. A selection of 56 amplicons were submitted for DNA sequence determination. Of all the sequences queried on the NCBI and Ribosomal Development Project (RDP) databases, 95/111(86%) were concordant with the results obtained from the reference laboratory. Study findings have shown that the selected pan-fungal PCR, coupled with DNA sequence analysis is an excellent diagnostic tool for the identification of medically relevant fungi. This assay, in combination with conventional culture, is useful for the rapid and accurate identification of fungal isolates. Future work will involve evaluating the utility of this assay for the detection and identification of medically relevant fungi in deep tissue biopsies

An Outbreak of Lymphocutaneous Sporotrichosis among Mine-Workers in South Africa

<div><p>Background</p><p>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.</p><p>Methodology</p><p>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 partially-healed lymphocutaneous lesions. Environmental samples were collected from underground mine levels. <i>Sporothrix</i> isolates were identified by sequencing of the internal transcribed spacer region of the ribosomal gene and the nuclear calmodulin gene.</p><p>Principal Findings</p><p>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 42 miners 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 <i>Sporothrix schenckii</i> sensu stricto by calmodulin gene sequencing while environmental isolates were identified as <i>Sporothrix mexicana</i>.</p><p>Conclusions/Significance</p><p><i>S</i>. <i>schenckii</i> 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.</p></div

Minimum inhibitory concentrations for the yeast phase of <i>Sporothrix schenckii</i> complex isolates, n = 13.

<p>*Species-level identity was determined by sequencing of the nuclear calmodulin gene;</p><p>^†multiple isolates from the same patient were not tested (i.e. isolates 38.2, 41.2 and 41.3);</p><p>abbreviations: AMB: amphotericin B; VRC: voriconazole; POS: posaconazole; ITC: itraconazole; BMD: broth microdilution test.</p><p>Minimum inhibitory concentrations for the yeast phase of <i>Sporothrix schenckii</i> complex isolates, n = 13.</p

Epidemic curve with cases of confirmed and probable sporotrichosis detected at a reopened section of a gold mine by month, Barberton, 2009–2011, n = 17.

<p>Epidemic curve with cases of confirmed and probable sporotrichosis detected at a reopened section of a gold mine by month, Barberton, 2009–2011, n = 17.</p

Phylogenetic analysis of the partial calmodulin gene sequences from 10 clinical outbreak isolates, 5 environmental outbreak isolates, 9 unrelated clinical strains and 10 reference strains.

<p>Phylogenetic analysis of the partial calmodulin gene sequences from 10 clinical outbreak isolates, 5 environmental outbreak isolates, 9 unrelated clinical strains and 10 reference strains.</p

A patient with probable sporotrichosis of the upper limb with a chain of healed lesions in a classic lymphocutaneous distribution.

<p>A patient with probable sporotrichosis of the upper limb with a chain of healed lesions in a classic lymphocutaneous distribution.</p

Epidemiologic Investigations into Outbreaks of Rift Valley Fever in Humans, South Africa, 2008–2011

Rift Valley fever (RVF) is an emerging zoonosis posing a public health threat to humans in Africa. During sporadic RVF outbreaks in 2008–2009 and widespread epidemics in 2010–2011, 302 laboratory-confirmed human infections, including 25 deaths (case-fatality rate, 8%) were identified. Incidence peaked in late summer to early autumn each year, which coincided with incidence rate patterns in livestock. Most case-patients were adults (median age 43 years), men (262; 87%), who worked in farming, animal health or meat-related industries (83%). Most case-patients reported direct contact with animal tissues, blood, or other body fluids before onset of illness (89%); mosquitoes likely played a limited role in transmission of disease to humans. Close partnership with animal health and agriculture sectors allowed early recognition of human cases and appropriate preventive health messaging