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The East African : Oct 13th 2014
34 The EastAfrican OUTLOOK OCTOBER 11-17,2014 S CI E N C E New breath test to ease TB diagnosis The test will lead to ea≥ly t≥eatment of Multi-d≥ug ≥esistance TB By CHRISTABEL LIGAMI Special Correspondent A new breath test for drug resistant tuberculosis that gives results within 10 minutes has been developed. Scientists from the US say the rapid test will lead to early diagnosis and treatment of multi-drug-resistance tuberculosis (MDR-TB). MDR-TB is a form of tuberculo- sis that is resistant to two or more of the primary drugs used for the treatment of TB. Currently a new DNA detection technique called GeneXpert has been endorsed by WHO. From a sample of sputum it can be detected whether one has TB and whether it is resistant to one of the key drugs, rifampicin, in about three hours. But for full drug resistance information, the patient has to wait longer. In a study published in the jour- nal Nature Communications, the scientists say the current commonly used TB test — the standard method — takes up to six weeks to detect MDR TB. “There is an urgent need for rapid, point-of-care diagnostic tools for tuberculosis and drug sensitivity,” say the researchers. The scientists used an inhaled form of isoniazid — an antibiotic commonly used to treat the disease — which is activated by a TB enzyme. They found that TB bacteria emit a unique gas signature within 10 minutes of exposure to this inhaled antibiotic in rabbits. Also the test was able to almost instantly provide information on drug resistance, which would normally take up to six weeks using current diagnostic methods. However, as the research has focused only on rabbits so far, the next step will be to try the test in humans. PREVALENCE In 2012, there were about 1,000 MDR-TB cases reported in East Africa The WHO estimates that TB infects 8.6 million people each year worldwide and kills 1.3 million, second only to HIV. Kenya recorded 225 newly confirmed cases of MDR-TB Uganda recorded 89 new cases Rwanda reported 58 new cases Tanzania reported 42 cases and Burundi 24 cases. If the test is successful within a clinical setting, there is hope that it could boost early diagnosis and treatment of TB.” Graham Timmins, lead researcher “If the test is successful within a clinical setting, there is hope that it could boost early diagnosis and treatment of TB, which are crucial to the global fight against the disease,” said Graham Timmins, associate professor at the University of New Mexico, US, who led the research. A medical worker at a mobile testing facility for TB in Tanzania. Picture: File TB is difficult to treat, requiring at least six months of treatment with multiple drugs. Rapid, accurate diagnosis is critical for timely initiation of treatment. Childhood TB is also very dif- ficult to diagnose, meaning the true case burden of paediatric TB is probably higher than estimated, and many children in need are not identified and therefore do not receive TB treatment. Most high-burden countries still rely on sputum smear microscopy, which cannot detect drug resistance. Tests to detect resistance are available only in regional or referral laboratories in most countries. The WHO estimates that TB in- fects 8.6 million people each year worldwide and kills 1.3 million, second only to HIV. In 2012, there were about 1,000 MDR-TB cases reported in East Africa. Kenya recorded 225 newly confirmed cases of MDR-TB, followed by Uganda which recorded 89 new cases; Rwanda 58; Tanzania 42 and Burundi 24 cases, the least in the region. The biggest recent change in the TB diagnostics technology has been the introduction of the GeneXpert automated molecular diagnostic machine. WHO recommended the Gen- eXpert machine, which provides a two-hour diagnosis of TB, in December 2010. In East Africa Kenya, Uganda and Tanzania are using the machine to detect whether the TB strain can be treated with rifampicin, one of two main drugs used to treat the disease However while the Xpert offers rapid testing, it remains expensive and not adapted for decentralised health-care settings. According to Eunice Wahome a TB specialist at Kenyatta National Hospital, challenges related to the currently available TB diagnostics include issues of availability, affordability, quality, acceptability/ adaptability and delivery. “For example, there is no true, instrument-free, inexpensive point of care TB diagnostic test for use in the rural settings while the GeneXpert machine recommended by WHO offers rapid diagnosis in decentralised settings, the test is still expensive,” said Dr Wahome. Uganda ≥eco≥ds high ≥ate of HIV infections in child≥en BY HALIMA ABDALLAH Special Correspondent UGANDA faces a dilemma in its efforts to contain new HIV infections as it emerges that children and adolescents are not getting the required treatment and care. Data released recently by the Ministry of Health on HIV and Adolescents shows that 130,000 adolescents aged between 15 and 19 are living with HIV. Sixty three per cent of these are sexually active. According to the data, many of these young people do not have comprehensive knowledge on HIV, and practise unprotected sex. “It is our collective responsibility to reverse this trend and ensure that all HIV-exposed children are tested early and the infected ones promptly put on treatment,” said Aida Girma Unicef country representative. Uganda is at the forefront in the fight against mother-to-child transmission of HIV, and one of the few countries that has adopted and nationally rolled out lifelong anti-retroviral treatment (ART) for all HIV positive pregnant and breastfeeding women with remarkable success. “We note, however, that diagnosis and treat- ment of infected children has not achieved similar progress as less than 40 per cent of children in need of ARTs are enrolled in active care,” Ms Girma added. In Uganda, like elsewhere in the world, chil- dren born with HIV are becoming adolescents while others have grown into adults. Even though it was known that the children would live with the chronic infection, experts globally focused treatment and care on infected adults. “We put a lot of attention on adults in the past because at the time, there were no doses for children and medical workers were not comfortable administering adult drugs to children,” said Dr Alex Ario, programme director of the Aids Control Programme at Uganda’s Ministry of Health. “Now we have the right doses and the medical workers are following guidelines on how to treat and care for the children,” Dr Ario added. However, many mothers are still hesitant to take their children for treatment over thestigma associated with the disease. It is even worse for mothers who have to walk long distances to the health facilities to get medication. In some instances, the drugs are not available. Out of 1,340,000 people in need of treatment, 640,000 are currently accessing ART – slightly less than 50 per cent. WHO statistics show that globally, more than 2 million adolescents aged between 10 and 19 are living with HIV, which most of them acquired from their mothers. Unicef estimates that about one-seventh of all new infections occur during adolescence. Hippos resting by a river. Pic: File Changes in genetic makeup responsible for height Subtle changes in our genetic make-up could help to explain why some people are taller than others, the largest ever study of height has suggested. About 400 genome regions have been identified that may be responsible for the extra inches, according to research involving more than 250,000 people. Scientists say this could pave the way for a simple test to reassure parents with fears about their child’s growth. It may also shed more light on cancer, where cell growth is out of control. BRIEFS Ugandan health worker dies from Marburg fever A Ugandan health worker has died in Kampala after an outbreak of Marburg, an infectious haemorrhagic fever similar to Ebola, authorities said, adding that 80 people who came into contact with him had been quarantined. Samples were taken and tested at the Uganda Virus Research Institute, and results confirmed the man had the Marburg virus. His brother, one of the people he came into contact with, has developed similar symptoms and has also been quarantined. Genetic screening good for bowel cancer patients Younger bowel cancer patients should be offered a genetic test to screen for a rare condition linked to a higher risk of further cancers, say researchers. Genetic screening of tumours would save lives and would be cost-effective, according to the study published in the Health Technology Assessment. Lynch syndrome raises the risk of developing cancer, particularly bowel cancer and womb and ovarian cancers. They say screening for the genetic condition in under-50s would be costeffective and prevent new cases in both them and their relatives. Scientists discover rich fauna in Tanzania, Kenya A study by an international team of scientists coordinated by Italy’s MUSE—Science Museum has updated knowledge on the faunal richness of the Eastern Arc Mountains of Tanzania and Kenya and revealed the discovery of 27 new species. The 23 amphibians and reptiles identified emphasise the area’s exceptional biological importance and strenghen its candidature for the Unesco’s list of World Heritage Sites.
Oct 6th 2014
Oct 20th 2014