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Treatment Helps In Preventing Tuberculosis Among Those At High Risk
By: JAMA on Aug 28 2005
Treatment of Tuberculosis
The drug isoniazid reduced the incidence of tuberculosis among HIV-infected miners in South Africa, a population at high risk of TB, according to a study in the June 8 issue of JAMA, a theme issue on tuberculosis.
Lead author Alison D. Grant, M.B.B.S., Ph.D., of the London School of Hygiene and Tropical Medicine, London, presented the findings of the study at a JAMA media briefing on tuberculosis at the National Press Club.
A major consequence of the human immunodeficiency virus (HIV) epidemic in developing countries is the increasing incidence of tuberculosis (TB), according to background information in the article. The cornerstone of TB control programs is the World Health Organization (WHO) strategy known as DOTS (directly observed therapy, short course), which may be effective in controlling drug resistance but has not prevented rising TB incidence in regions with high HIV prevalence.
The impact of HIV on TB is illustrated by data from gold mines in South Africa, where overall TB incidence now exceeds 4,000 per 100,000 population per year (i.e., 4 percent). Tuberculosis incidence was already high in this setting before the spread of HIV infection, largely because of a high prevalence of silica dust exposure. Rising HIV prevalence has resulted in increasing Tuberculosis incidence, despite well-implemented TB control programs. Additional interventions are required to reverse the rise of TB in such settings.
In collaboration with the mining health service, the study team established a clinic for HIV-infected employees in a gold mining company in South Africa in 1999 to provide specialist care for HIV-infected employees, including preventive therapy (isoniazid and cotrimoxazole). This study evaluates the effect of this intervention. The authors analyzed 1,655 HIV-infected males (median age, 37 years) attending the clinic between 1999 and 2001 (before antiretroviral therapy was available). Median follow-up was 22.1 months. Employees were invited in random sequence to attend a workplace HIV clinic. Isoniazid, 300 mg/d, was self-administered for 6 months among attendees with no evidence of active tuberculosis.
A total of 1,016 of 1,655 men included in the analysis attended the clinic at least once. Six hundred seventy-nine (97 percent) of 702 men eligible to start primary isoniazid preventive therapy did so. The researchers found that the tuberculosis incidence rate before vs. after clinic enrollment was 11.9 vs. 9.0 per 100 person-years, respectively (incidence rate ratio [IRR] after adjustment for calendar period, 0.68 [32 percent reduced incidence]). In further analysis adjusting for calendar period, age, and silicosis grade, the tuberculosis IRR for clinic enrollment was 0.62 (38 percent reduced incidence). In analysis excluding individuals with a history of tuberculosis (and, hence, ineligible for isoniazid preventive therapy), the adjusted IRR for clinic enrollment was 0.54 (46 percent reduced incidence).
"Despite our intervention, the TB incidence rate in the postclinic phase remained unacceptably high at 9 per 100 person-years," the authors write.
"Additional interventions such as secondary preventive therapy and antiretroviral therapy [which is now being rolled out among the workforce] are required to reduce the very high residual morbidity attributable to TB in this community. Further work is needed to determine how best to use available interventions to minimize TB morbidity in areas where both HIV and TB are highly prevalent," the researchers conclude.
(JAMA. 2005;293:2719-2725) - WASHINGTON, D.C.
IN THE DEVIL'S MINER IT'S BOLIVIAN CHILDREN WHO PAY THE PRICE FOR CHEAP SILVER
BRIAN GIBSON / brian@vueweekly.com
Documentary reveals harsh existence of two young silver miners
In Bolivia, one of the poorest countries in the Americas, lies the highest city in the world, 4300 metres above sea level. And over Potosi, its wide slope strewn with cloud or cast in shadow, the stark and implacable mountain of Cerro Rico looms.
Inside the mountain, in dank tunnels that can reach temperatures of 40 degrees, Bolivian children mine for silver worth US$13 or $14 per pound.
Two of these kids are 14-year-old Basilio Vargas and his 12-year-old brother Bernardino. The tender, humble home life of the fatherless Vargas family is built on the rough-scrabble, back-breaking quest for veins of silver. The four of them depend on the boys’ money and the little extra that the mother makes for guarding miners’ tools in their stone house up on the mountain.
Keif Davidson and Richard Ladkani’s The Devil’s Miner, an achingly scored and exquisitely shot documentary, watches the Vargas brothers as they sit on rubble outside the mine with the silhouettes of peaks spreading out in the dusk before them, chewing coca leaves in order to fortify themselves for a 12- or 24-hour shift of work underground.
We trudge after these two boys as they gently prod sticks of dynamite into holes in the rock or scurry up into nooks and crannies in the sides of mining shafts, jumping out of the way of brakeless wagons being pushed full-tilt along the tracks by grimy men. Of the 800 children who work in Cerro Rico, the boss of one cooperative-run mine notes sombrely, “It is an incredible sadness. They are throwing their bodies into the same fire that we do.”
The Devil’s Miner is fuelled by the unearthly tension between the workers’ outer and inner worlds. The city’s churches are far from the dark, hot, arsenic-tainted shafts, and once inside, the miners give offerings to Tio, or Satan, their subterranean protector. After Sunday mass in Potosi, miners gather above the city for the sacrifice of a llama, whose blood they spread on themselves and splatter on the entrance to the mine in an effort to appease the master of their hellish second home.
The red-eyed, horned idols of Tio found in every mine are a legacy of colonialism—the Spaniards apparently built many of them in order to intimidate the Indios into continuing to slave away for them.
Now, the usually native miners—who often die at 35 or 40 from silicosis, caused by the tunnels’ dust accumulating in and slowly eating away at their lungs—eke out a grudging, perilous, subsistence-wage living with their labour in the “mountain that eats men alive,” so named because 8 million are said to have died in Cerro Rico.
The Vargas brothers hope to escape the mines—Basilio finds work at a better-paying, more dangerous mine, where pneumatic hammers spew the fatal dust up around cloth-muffled drillers—by saving up enough money for themselves and their sister Vanessa to go to school, where the students will call a miner “rock thief” or “dust sucker.”
By afternoon, the uniformed Basilio has left his Christianity-promoting, disciplinarian school and is slogging his way through muddy puddles and claustrophobic caverns. The camera practically bores its way into the rock as it follows the light of the acetylene flame on his helmet into the descending darkness.
This is an unflinching, unforgettable glimpse at two boys who have been aged beyond their years by grinding work that they must endure for the faint hope of a different future. But it is just a glimpse—as one miner says, “Nobody can grasp what they are going through. The lives they have lived.” V
Thu, Feb 23 (7 pm)
The Devil’s Miner
Directed by Keif Davidson,
Richard Ladkani
Featuring Basilio Vargas,
Bernardino Vargas
Metro cinema, $8 |
