HEALTH

Mine over matter

Prof. Gavin Churchyard, CEO of the Aurum Institute for Health Research
Prof. Gavin Churchyard (1).jpg

The harsh reality is that 1% of gold miners die annually – and 4% are sent home ill.

One in every hundred gold miners in South Africa has been dying annually for at least the past 10 years — and the mortality rate, fed by the HIV/TB epidemic, shows no sign of changing anytime soon. An additional 4% of gold miners are repatriated home (medically boarded) due to ill health (mainly lung disease) — roughly five times the national workforce average.
This is according to two top medical experts at the heart of the mining industry, who add that historic upheavals (like the infamous Marikana Mine protest killings on August 16, 2012) and the ongoing inter-union strife significantly affect essential health monitoring and research.
Professor Gavin Churchyard, CEO of the Aurum Institute for Health Research, a not-for-profit public benefit organisation with roots in the mining industry, also revealed that what was previously hoped to bring down the TB prevalence among highly migratory gold miners, wide-scale prophylactic drug intervention among asymptomatic (dormant) carriers, has been found to have little protective effect.
This has far-reaching and sobering implications for the ongoing nation-wide spread of TB whose incidence (new cases over time) is driven by HIV. He explains that the moment a TB carrier (dormant) becomes HIV positive and their immune system is progressively compromised, their risk of developing active TB increases. “The prevalence of undiagnosed TB disease is the driving force of TB transmission at a population level,” he added.

Debate on limiting underground time
Gold miners, because of their long-term exposure to silica-dust deep underground, are highly prone to developing silicosis with attendant TB (latent or active). Gold miners make up 32% of all miners in the country. Debate in mining medical circles currently revolves around whether legislation should require mining houses to limit the number of years a worker spends underground to 10 or 15 years (Brazil has set the ceiling for certain job categories at 10 years).
Churchyard says silicosis prevalence “jumped dramatically” among gold miners after 15-20 years of underground work, but describes reducing this time frame as a currently “un-validated intervention”. The high prevalence of undiagnosed active TB, which is responsible for ongoing TB transmission rates in the population, has not changed much, based on two surveys a decade apart.
The first Aurum Institute survey, in 2000 including some 2 000 gold miners, revealed that 2,5% of them had undiagnosed (active) TB. The second probe in 2011 (this time of 13 000 gold miners) done as part of Churchyard’s latest research, recently published in the New England Journal of Medicine, uncovered a prevalence of 2,3% — despite widespread campaigning for and administration of prophylactic isoniazid preventative therapy (IPT).
This is cold comfort to those revelling in nationwide HIV successes, including an anti-retroviral treatment (ART) programme now reaching 2,3 million South Africans, (up from 923 000 in 2009).
HIV prevalence in the mining sector is currently unclear – the last survey in 2000 put it at 30%, almost triple the national average. Churchyard boasts of a 10% or lower HIV prevalence from some mining houses with a pinch of salt, observing; ‘these are often based on unreliable and typically unrepresentative’ samples. He concedes that the mining sector led the way in the national ART roll-out, but says current individual mining house HIV prevalence measurements are shaky.
Representative HIV prevalence surveys done by independent research bodies and supported by labour are required to monitor the impact of HIV programmes on the HIV epidemic, he emphasises.
Dr Thutula Balfour-Kaipa, head of Health for the South African Chamber of Mines (SACOM), agrees that HIV surveillance on the mines was “very much determined by the approach and attitude of the relevant union”. While it was understandable that many unions were uncomfortable with the idea of linking an HIV test to someone, mining houses made a strict distinction between occupational health and primary health care.
“The occupational health officer who determines your fitness to work doesn’t know your HIV status, but there are still pockets where the union does not support testing.”
She says the current volatile union environment, doesn’t help – when unions are struggling for survival, issues like health tend to take a back seat.
Another added complication in measuring HIV prevalence was workers who belonged to a medical aid being tested privately. In spite of this, anecdotal evidence was that HIV rates had stabilised along with those in the general population. She says mining houses with the largest numbers of migrant workers (gold and platinum) had the highest levels of HIV and were thus above the national average.
“You may find prevalence at 18% on a gold or platinum mine but as low as 12% in the coal sector (low migrancy).”
Balfour-Kaipa says a final tally currently being completed on 2013’s fatal mine accidents “looks like it’s going to be under 100 workers, making it a landmark year, given that in 2012 there were 123 deaths (excluding the 34 Marikana killings)”. The COM believed that health on mines had improved overall — TB is a huge part of this, so even a small improvement there helps a lot.
“The concern now is silicosis; we’re not really happy with progress on this. Silicosis is the product of both concentrations of dust and length of exposure. We assume mines are doing everything possible to get dust levels as low as possible but the length of exposure is our biggest challenge”.
Balfour-Kaipa admits that there were no national guidelines on duration of exposure. If government, labour and the employers decided to “go this route, we’d have to be very clear on what happens to a person and their job”.
She says there was no active discussion on this yet. “We’d like to see stability at union level so that we can focus on health. With all these political battles, strikes, and membership strife, health and safety come last.”
Churchyard told Leadership no hard data existed on national medical boarding rates — but when pushed, estimated the figure at around 0,1% or 0,2% of the national work-force. “The gold mining sector medical boarding rate is 1%, making it a possible five to 10 times higher.”

Phasing-out of single sex hostels a relief
When both executives were asked by Leadership about changes in accommodation for miners (the proportion of miners in single sex hostels was 90% in early 2000), they said this had dropped to well below 50%, a hugely positive HIV and TB transmission risk reduction. Other positives included the sharing of HIV/TB health services between richer and poorer mines.
Churchyard says one of the most dramatic changes in national health policy recently was the introduction of continuous IPT for immune-compromised people for three years, making South Africa one of the first countries in the world to add IPT to ART for longer than a period of six months.
He explained that IPT was “like an umbrella – it only protects you from the rain (of TB disease) for as long as you keep it up”. Adding IPT to the ART regimen meant that the national TB incidence could be kept down, thus reducing the pool of TB infectious people and having an overall population level impact.
From less than one percent of all HIV infected South Africans on IPT five years ago, (which he called “inexcusable” at the time), more than 370 000 of the 2,3 million people on ART were now on IPT.
This was in line with international best practice and the World Health Organisation guidelines. Churchyard says the national TB rate peaked in the year 2008 and started to decline — but even with a slight drop, South Africa had the second highest TB rate or epidemic in the world (one in one hundred people).
Gold mine TB rates stood at three in one hundred workers nationwide, platinum one to two in one hundred workers, while coal mirrored the national rate with the diamond mining sector even lower.
HIV drives not only TB, but also bacterial pneumonia, cryptococcosis, enteritis, bronchitis, urinary tract infections and soft tissue infections.
This is according to a major paper, Morbidity and Mortality in South African Gold Miners: Impact of Untreated Disease Due to Human Immunodeficiency Virus, which Churchyard contributed to in the American journal, Clinical Infectious Diseases. Cryptococcosis (a fungal infection leading to lesions or abscesses in the brain and central nervous system) caused 44% of deaths in HIV positive patients.
Balfour-Kaipa says data from the Department of Mineral Resources shows that occupational TB reported by gold mines had dropped from 4 500 in 2007 to 2 838 in 2012.
Churchyard warns against official underestimation; he said these figures came from routine data collection and recorded only cardio-pulmonary TB in miners who had done risk work (defined as more than 200 risk shifts).
Balfour-Kaipa told Leadership that analysis of annual reports from the majority of South African mining companies shows that TB rates had declined from 1 387 cases per 100 000 workers in 2010 to 1 031 cases per 100 000 in 2012.
Silica dust was responsible for TB in the gold sector being up to three times the average South African rate over “the past several decades”.

Take-home message
The health executives’ main take home message is very similar to that of the National Health Minister, Dr Aaron Motsoaledi: go back to basics; scale up HIV testing, speed up access to ART, initiate ART earlier (at a CD4 cell count level of 500, not 350), rapidly scale-up the use of new TB diagnostic technology and limit miners’ exposure to dust.
Taken together these measures will have a major impact on TB rates and HIV infections in South Africa.

Chris Bateman

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