Posts Tagged ‘tb’

The Regional Tuberculosis Centre (RTC) in Pokhara is the chief Nepalese government TB facility in the country’s Western Region. It provides diagnostic and treatment services as well as technical support for TB control activities in the region.

WHO issues new recommendations calling for accelerated uptake of testing and treatment for TB prevention

The World Health Organization (WHO) recommends scaling up access to testing and treatment for TB infection, especially among groups who are particularly at risk, such as small children and people living with HIV. The move will expand access to testing and care for people with latent TB infection (LTBI). People with latent TB may develop active TB in the future if they do not receive appropriate treatment.


“The new WHO guidelines will help countries catalyze TB prevention and contribute to ending the TB epidemic,” said Dr Tereza Kasaeva, Director of WHO’s Global TB Programme. “Making sure everyone can obtain the treatment they need, to prevent latent TB developing into active TB, will save lives and reduce suffering.”


The new WHO Updated and consolidated guidelines for programmatic management of Latent TB infection, recommend action on three fronts:

  • Expanding the number of groups being prioritized for latent TB infection testing and treatment. Health practitioners have been prioritizing testing and treatment of people living with HIV and children under the age of 5 who have been in contact with people who have TB. WHO has now identified HIV-negative children aged ≥ 5 years, adolescents and adults who are contacts of TB patients, as well as contacts of patients with multidrug-resistant TB (MDR-TB), as additional high-risk groups.
  • Expanding the testing options: WHO recommends scaled-up testing for latent TB infection in both high- and low- TB- burden countries. A tuberculin skin test or interferon-gamma release assay can be used to test for latent TB infection. Active TB disease should always be ruled out before prescribing preventive treatment, as per WHO guidelines.
  • Expanding the treatment options: WHO is recommending two new shorter treatment regimens to treat latent TB infection. Rifapentine and isoniazid weekly for 3 months may be offered as an alternative to 6 months of isoniazid monotherapy as preventive treatment for both adults and children. Rifampicin plus isoniazid daily for 3 months should be offered as an alternative to 6 months of isoniazid monotherapy as preventive treatment for children and adolescents aged < 15 years. These shorter regimens will help patients adhere to their treatment and complete it.

WHO is also releasing a mobile application to support programmatic management of latent TB infection. Countries are encouraged to adapt this tool to the country context and ensure systematic monitoring and evaluation. Access the mobile application here.

“The scale-up of TB preventive treatment has been slow. Only twelve of the 30 countries with a high burden of HIV-associated TB reported provision of TB preventive treatment among people living with HIV, and only 13% of the 1.3 million eligible children received preventive treatment in 2016,” said Dr Haileyesus Getahun, Coordinator for TB/HIV and community engagement, WHO Global TB Programme. “We hope the new guidelines will disrupt the status quo in many countries and leapfrog global implementation of TB prevention efforts.”

The consolidated guidelines are expected to guide the development of national guidelines for latent TB management, adapted to the national and local epidemiology of TB, the health infrastructure and other national and local determinants. The guidelines will also contribute to global and national responses in finding and reaching those TB patients not in care, through systematic screening and testing. The guidelines are to be used primarily in national TB and HIV control programmes, or their equivalents in ministries of health, and for other policy-makers working on TB and HIV and infectious diseases. They are also appropriate for officials in other line ministries with work in the areas of health.

“We really look forward to implementing these new guidelines, as they offer a number of opportunities, including simpler, shorter, preventive TB regimens, that will help reinvigorate scale-up of TB prevention for high burden countries like ours”, said Dr Yogan Pillay, the Deputy Director-General for Health in South Africa. “These guidelines clearly aim to be transformative and will go a long way in ensuring that no at-risk person gets left behind.”

These guidelines have been developed because countries have asked for them. WHO will work with countries to mobilize the resources required to ensure they are implemented.


Latent TB Infection : Updated and consolidated guidelines for programmatic management

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Antibiotik Lama Ini Berpotensi Jadi Obat Baru bagi Pasien TBC

Tuberkulosis (TBC) masih menjadi salah satu penyakit yang meresahkan masyarakat. Sampai saat ini, ilmuwan masih terus mencari obat yang tepat untuk memeranginya.

Saat meneliti D-cycloserin yang merupakan antibiotik lama, ilmuwan menemukan harapan baru untuk pengobatan penderita TBC.


Ilustrasi tuberculosis (TBC)(Bet_Noire)

Profesor David Roper di Warwick’s School of Life Sciences dan Dr Luiz Pedro Carvalho dari The Francis Crick Institute, menjelaskan keunikan kerja antibiotik D-cycloserin di tahap persenyawan molekular.

“Dalam penemuan baru ini, D-cycloserin terikat pada enzim ligase D-alanine-D-alanine dan mengalami modifikasi secara kimia pada enzim. Modifikasi kimia inilah yang belum pernah terlihat sebelumnya,” kata Profesor Roper.

“Kami sekarang mengerti keunikan obat antibiotik ini yang memiliki metode unik saat bekerja terhadap target yang  berbeda,” tambahnya, dikutip dari Labnews, Rabu (17/1/2018).

Antibiotik D-cycloserin  menghambat kerja dua jenis enzim berbeda yaitu racemase D-alanine dan D-alanine-D-alanine ligase. Kedua bakteritersebut diketahui saling terkait untuk membangun dan mempertahankan dinding struktural sel bakteri.

D-cycloserin akan membentuk ikatan molekular dengan kelompok kimia yang membuat enzim racemase D-alanin bekerja, dengan tujuan melumpuhkan enzim D-alanin itu.

Seperti diketahui, D-cycloserin adalah obat antibiotik produk lama yang efektif melawan banyak penyakit akibat mikroba, semisal tuberkulosis. Akan tetapi karena dianggap memiliki efek sampingnya berbahaya, obat tersebut hanya dijadikan cadangan kedua saat proses perawatan.

Saat ini, peneliti telah menemukan keunikan kerja kimiawi D-cycloserin terhadap sejumlah bakteri yang menjadi target. Kinerja kimiawai tersebut kemungkinan hanya dimiliki oleh antibiotik D-cycloserin saja di seluruh dunia.

Peneliti akan melakukan penelitian kembali dengan tujuan memodifikasi struktur D-sikloserin.

Harapannya, menghasilkan antibiotik yang lebih spesifik dan menghindari beberapa efek samping yang merugikan dan mengurangi efek samping kekebalan terhadap antibiotik saat infeksi.

“Dengan memahami proses molekuler dan seluler yang disebabkan antibiotik, kita akan benar mengerti bagaimana membuat obat yang lebih baik, yang sangat dibutuhkan dalam menghadapi ancaman resistensi antibiotik saat ini,” kata Dr Luiz Pedro Carvalho dari Laboratorium Metabolisme Mycobacterial and Antibiotic Research di Francis Crick Institute.



Harvard Study: Vitamin A Helps Protect Against TB


Raúl Silverio Carbajal / Partners In Health Hugo Iván Díaz Vásquez (left), a laboratory technician with PIH in Peru, preps patient samples in Carabayllo, a neighborhood north of Lima.


Tuberculosis is the most deadly infectious disease in the world, killing 1.8 million people in 2015 alone, yet little is known about why exposure to the airborne disease sickens some people and not others.

Harvard researchers think diet may be key to TB transmission. According to an article published in Clinical Infectious Diseases in May, people with low levels of vitamin A were at least 10 times more likely to develop TB after exposure to the disease than those with higher levels. Increasing consumption of vitamin A—found in carrots, sweet potatoes, dairy, meat, and supplements—could be a powerful tool in disease prevention.

Dr. Megan Murray, the Ronda Stryker and William Johnston Professor of Global Health at Harvard Medical School, and her team of investigators discovered this link as part of an epidemiological study of TB among people living in Carabayllo and surrounding districts north of Lima, Peru. Staff from Socios En Salud, as Partners In Health is known locally, were essential for recruitment, patient follow-through, and blood sample collection and analysis of the 12,000 participants over five years.

We spoke with Murray, PIH’s director of research, about the surprise findings, why adolescents with low vitamin A levels are particularly at risk, and what the vitamin A link means for TB prevention.

How did your team arrive at this discovery?*

Households in Carabayllo were recruited when somebody developed TB, so we knew that we were looking at a population that was relatively high risk. Among the 12,000 household contacts, about half had given a blood sample. We checked to see if people had undiagnosed TB at the time that we drew their blood. Then we followed people for infection, and then for disease. With TB, those are different. Lots of people were already infected. About half of the people who weren’t, became infected within the next 12 months—probably because of exposure. About 2 percent of the people developed active TB. We took those cases and matched them to people who were just like them in terms of age, gender, and other factors, but who hadn’t developed TB. Then we compared their vitamin A levels, and they were really different.

Were you surprised by that difference?

We were just stunned. We were actually interested in vitamin D. People had been speculating for many years that low vitamin D is associated with TB risk, based on a seasonal pattern. The argument is that the disease starts to progress in the summer and takes five or six months to manifest. We were following that up, but then we had some data from a previous study that Dr. Molly Franke, an assistant professor at Harvard Medical School, had done in kids that showed that fruits and vegetables, in a case-controlled study, were protective against TB. We thought, ‘Well, let’s throw in some fruits and vegetables that seem to be associated with various vitamins.’

We were just stunned.

It turns out that vitamin A is only minimally associated with fruits and vegetables; it’s actually more in dairy and meat. When we got this result—that contacts with low levels of vitamin A were at greater risk for developing active TB, we were like, “Whoa, that can’t be right.” We looked for every possible reason why it might not be right, but we do think it is right.

The 10-fold factor is striking. Can you put that in context?

It’s huge. The strongest risk factor that we know is between smoking and lung cancer. That’s a 20-fold risk. It’s not a great example, because it’s so extreme that it’s way out of the normal ballpark. When you think about something like smoking and heart disease, you know it’s a very strong link. A ton of the heart disease in the world is caused by smoking. But it only doubles the risk. As epidemiologists and public health people, we’re interested in odds that are as low as 1.1, which is a 10 percent increased risk. We’re talking here about 10 times or 20 times the risk.

Vitamin A-deficient adolescents had up to 20 times the risk of developing TB. Any idea why?

We know that TB rates are higher in that age group than in any other age group. As kids move into puberty, from 10 to 20 years old, they’re at enormously high risk. We don’t really know why that is.

Adolescent health is not something that is well studied, especially around immunity. We do know that there’s some infectious diseases that are much worse in adolescence. Because of the growth spurt, they have very different metabolic demands and processes.

Vitamin A deficiency is prevalent among 30 percent of the population in low- to middle-income countries. Why is this?

I’m assuming it’s because of diet. If you think about it, it’s in dairy, meat, and fish. These aren’t very common in our diet. And the poorer the country, the less vitamin A you’re going to get.

To support these recent findings, your team is now helping design a study to test vitamin A supplementation among guinea pigs exposed to TB. How far along are you, and do you see anything promising?

Our collaborators at the University of Colorado—Fort Collins set up a nice guinea pig model in diabetes. They can make guinea pigs diabetic and then see what happens with TB. One of the questions we’ve been asking is, ‘What effect do drugs routinely used for diabetes have on TB?’ They’re on to some very interesting stuff suggesting that some of the anti-diabetes drugs could be useful in controlling TB, regardless of whether you’re diabetic or not.

When we learned this about vitamin A, I asked them if they could set up a similar project. They designed it, and we are waiting minute-by-minute for NIH funding. We’ll be ready the minute they say, “Go!”

So how long will it be before we test a vitamin A intervention in humans?

We can try it today, because this is something we know is good for people. We don’t need animal results to proceed with a trial here. We know that people who are vitamin A deficient should be given vitamin A, regardless of their TB risk. The trial that we’re envisioning is really about whether people at risk for TB should be screened for vitamin A. If they were low, we would treat it.

What do you hope will come about as a result of this publication?

I’ve had people say, ‘Why bother with a clinical trial? Let’s just give everyone vitamin A.’ I agree with that to some degree. In the U.S., we don’t recommend people who are not vitamin A deficient to take it. People take enormous doses of vitamins, and they can actually take too much vitamin A. To get people on board and to have TB programs start thinking this is a good approach, having some evidence that it’s useful is going to be good.

The poorer the country, the less vitamin A you’re going to get.

If you live in the U.S. and somebody in the household has TB, you get screened by the public health department. They come and do a skin test for TB and, if you have it, you get six to nine months of a preventive drug. We’d like to do that in lower resource settings. But some countries say, ‘Our TB burden is just too high. We can’t give half our population these drugs.’

The nice thing about vitamin A is that it’s good for other things besides TB. There’s a lot of interesting research going on right now on the relationship of vitamin A and general immunity.

*This interview has been edited and condensed.