Drug resistant TB: Africa’s forgotten health crisis

[NAIROBI] Deric Mashinga recalls a night last December when he felt unwell and went to bed unusually early. “I was coughing uncontrollably and with chest pains,” says Mashinga. The next day he walked to the nearby health centre to seek medication.

肯尼亚卡卡梅加县湿布韦卫生中心的医务人员诊断出他患有肺炎和处方抗生素。Mashinga说：“三周后，我变得很好，但在三个星期后发出严重的咳嗽和胸部疼痛。”“我回到医院，那里的医生建议我向我被诊断出患有结核病的Kaimosi医院寻求帮助。”

Mashinga, a 32-year-old plumber, was devastated, but began medication after the doctor reassured him that he would recover in time. “I took the drugs consistently for the first three weeks but honestly never skipped drugs,” he says. Despite this, Mashinga’s situation deteriorated and he was confirmed as having multidrug-resistant tuberculosis (MDR-TB). He is still undergoing treatment, taking a second course of drugs.

当引起TB的细菌对治疗该疾病，利福平和异念珠菌的两种最有效的抗菌药物具有抗性时，就会发生MDR-TB。尽管在全球范围内，感染数量每年下降约2％，但每年有数十万个新病例，这种情况是谁称为public health crisis.

多哥洛美大学的药理学研究员弗雷德里克·艾哈利（Frederic Ahiator）说，患者最常由于抗生素滥用而产生对抗菌药物的抗菌株。他说：“当患者不遵循规定的剂量或所需治疗的持续时间时，很明显，这些药物对他无效，并且他会产生多药耐药性菌株。”

TB is responsible for 1.6 million deaths globally each year, with Africa bearing the most severe burden, WHO figures show. The organisation estimates that in 2017 there were 558,000 new cases with resistance to rifampicin, the most effective first-line drug.

Immunologist Mohlopheni Marakalala at the Africa Health Research Institute in South Africa, says MDR-TB requires more drugs than non-resistant strains and most patients are unable to take the complete dosage for the required six months. “This makes the bacteria that affects patients become resistant to drugs,” Marakalala tellsSciDev.Net.

Marakalala says that drug resistance is fueled by continued transmission of the disease, propagated by poor living conditions, especially shared hostels, informal settlements and mining environments.

The BCG vaccine that is used for TB prevention is effective in children but generally not in adults. “If we need to meet the [UN] goals of eradication by 2050, we need effective vaccines,” Marakalala says.

该国国家结核病计划主管Yacine Mar Diop说，在塞内加尔，卫生工作者正试图解决完成药物课程的障碍。

"When a patient is undergoing treatment for pharmaco-sensitive tuberculosis, knowing that it is a six-month treatment, the patient must go to the nearest care centre to take his medication for the first two months," she says.

如果病人不可能这样做, there are “community relays” who will administer medication at the patient’s home.

"With drug-resistant TB, this is an accompanying procedure that does not stop at the beginning of treatment, but continues throughout treatment," says Mar Diop.

But MDR-TB is still a challenge in Senegal. There are an estimated 300 cases of drug-resistant tuberculosis each year, according to a 2014 survey by the national TB programme.

Mar Diop说，冗长的药物方案和不良副作用会导致患者放弃治疗，从而促进了抵抗的出现。这些药物通常会引起严重的呕吐，这也可能导致该药物吸收不良。

According to Mar Diop, 13,665 cases of TB were recorded in Senegal in 2017, but this figure represents only two thirds of the total estimated cases. The remainder, she says, are never identified and stay in their communities, thereby sustaining the epidemic.

在肯尼亚，国家结核病，麻风病和肺部病计划（NLTP）将结核病列为该国第四大死亡原因，介于每年5,000和15,000人死亡。这些情况很大一部分是MDR-TB。NLTP的结核病护理和治疗负责人斯蒂芬·穆雷什（Stephen Muleshe）说，确认这些情况是一个重大挑战。But according to the WHO, there were 669 recorded cases in the country, with the true number estimated to be around 1,300.

Kenya plans to introduce the injection-free therapy recommended by WHO for drug-resistant TB. The oral drugs, delivered over a period of 18-24 months, have fewer side effects and are more effective. “We are going this direction because injections have had many adverse effects on patients including hearing impairment,” says Muleshe. “We have done ad-hoc interviews with MDR-TB [patients] and almost all of them prefer longer therapy with no side effects.”

但除非医生治疗病人是很困难的can identify who has MDR-TB in the first place. In 2010, Kenya introduced a test called GeneXpert that can identify TB bacteria and determine whether they are resistant to Rifampicin by analysing DNA. This has been a great step for Kenya to combat MDR-TB, according to Muleshe.

However, Mar Diop cautions that the technology is too costly to make it widely available in Senegal and says more resources are needed for equipment and training.

Marakalala also stresses the need for better diagnostic tools, as well as short-term therapies. “Africa has the capacity to find lasting solutions to MDR-TB,” he says. “The case of HIV management in Africa through improved diagnostics leading to victims having a longer life is a classic example that [shows] the continent can control multidrug-resistant TB.”