Scientists develop new regimen to prevent TB, HIV

Antibiotic Bacteria
Representational picture. Pixabay

One of the deadliest diseases that kills more than 1.6 million people across the world each year because of no preventive regime, Tuberculosis, may soon get a preventive drug as a new drug course of a month may be effective in preventing TB, a study paper has said.

The study showed a regimen of isoniazid and rifapentine taken daily for a month effectively prevent TB. It is more safe and can most likely be completed than the traditional nine-month course of isoniazid.

The progress gives scientists a hope against the disease that remains the leading cause of death worldwide, and target WHO End TB Strategy to effectively prevent and treat the disease.

"Multidrug-resistant and rifampin-resistant tuberculosis remain a global health threat, and this regimen when administered by routine tuberculosis treatment programs has resulted in successful treatment in about 55 percent," suggested the study published in The New England Journal of Medicine.

According to a study, one in every three people worldwide harbour the TB bacteria and just one in 10 develop the disease, with treatment more difficult and costly in drug-susceptible tuberculosis.

"The biggest issue is to identify those 10 per cent," The Independent cited senior coordinator for TB at a nonprofit Global Fund, Dr Eliud Wandwalo, as saying.

He added that scientists did not have any good indicator to show which of these 1.8 billion people carrying the bacterium might become sick.

The standard course for TB treatment for decades involved antibiotic isoniazid, which kills the bacteria only when they are replicating and needs to be taken daily for nine months in the hope of catching the bacteria as they multiply.

Isoniazid, however, causes numbness, nausea and fever, as well as, liver toxicity so people are advised not to drink alcohol for the entire nine months when taking the drug.

"The completion rates have been very poor," said Alison Grant, an epidemiologist at the London School of Hygiene and Tropical Medicine, and added that scientists off late have come up with two shorter courses -- a drug called rifampin taken every day for four months or a combination of isoniazid and rifapentine taken once weekly for three months, but still remembering to take all 11 pills together once a week can be more challenging than taking them every day.

But the new development reviewed by the WHO in July, expected to be endorsed later this year, and likely to be approved for HIV patients, can be a game changer in even preventing HIV as the study was conducted only on HIV infected people.

"If we had an intervention for HIV that reduces mortality by 37 per cent, the WHO would have an emergency meeting and the drug would be recommended for uptake in the entire world," Chaisson argued, adding that people just sort of shrug when it is for TB.

According to him, cost effectiveness can be another hurdle as the new course, which also relies on rifapentine like the three-month one, needs three-folds quantity of the drug dropped to $32 from $71 after a year-long advocacy campaign to lower the costs.

Dr. Gavin Churchyard, a TB specialist based in Johannesburg, said there was still more optimism about TB prevention than ever before despite the high costs of the drug manufactured by Sanofi, if supported by political will such as in South Africa.

"South Africa once had an abysmal TB preventive therapy programme, with just a few thousand people taking the pills, but the numbers began to rise dramatically after TB prevention was made in 2008 a national priority. South Africa today has the world's largest TB preventive therapy programme," explained Churchyard.

According to a Lancet report, about 4·6 percent patients globally have multidrug-resistant tuberculosis, although the percentage is much higher (over 25 percent) in countries such as Kazakhstan and Ukraine.

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