In-depth: The New face of TB: Drug resistance and HIV
KENYA: Drug resistant TB taking hold in urban slums
Photo: Richard Etienne/IRIN
The slums are the ideal environment for TB to thrive
NAIROBI, 29 March 2007 (IRIN In-Depth) - Multidrug-resistant tuberculosis (MDR-TB) is taking an upward turn in the slums of the Kenyan capital, Nairobi, which are the perfect breeding ground for the disease, according to health workers.
Dr Dave Muthama, programme officer for Kenya's National Leprosy and TB Control Programme, told IRIN/PlusNews that although only 46 cases of MDR-TB had been confirmed in the country, the figure could be much higher.
"It is difficult to get good cultures, therefore it is difficult to work out what proportion of patients have MDR," said Christine Genevier, head of mission for the international medical charity, Médecins sans Frontiéres (MSF).
The sputum tests most commonly used to detect TB often fail to recognise it in HIV-infected patients, so the most reliable way of diagnosing TB in HIV-positive patients is by culture testing, in which sputum samples are cultivated in a special liquid. Dr Liesbet Ohler, MSF's TB coordinator, explained that it was more difficult to diagnose TB when someone was also infected with HIV.
FAST FACTS:
- One in 10 new TB infctions are resistant to at least one anti-TB drug
- About 4 percent of all new and previously treated cases of TB globally are MDR strains
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"People who are HIV-positive have a much lower [level of] TB bacilli in their sputum, so that the sputum test may come back negative and the chest x-ray may also look normal," she said. "The immune system is weakened, so the disease develops with less visible signs - less TB is needed to make a person ill with the disease - so people need to be treated on clinical signs before it is too late."
According to Genevier, "There is a lack of labs, a difficulty in diagnosing HIV co-infection and lack of follow-up [of patients taking TB medication]." MDR-TB develops when a TB strain becomes resistant to two or more first-line antibiotic drugs.
"MDR-TB can be acquired either through treatment failures when the patient did not adhere to the treatment properly; when the disease was resistant to the treatment, or directly from an MDR-TB sufferer," she said.
Ohler commented that the "dark and airless" homes in the slums were the ideal environment for TB to thrive. A 2004 report by the Kenya Medical Research Institute estimated that 70 percent of Nairobi's population lived in slums, and a large percentage of HIV-positive cases co-infected with TB came from these areas.
She suggested that stigma could be one reason why people defaulted on their treatment. "Here in Kenya so many people are HIV and TB co-infected, so if you say [you have] TB, people assume [you are infected with] HIV."
The ups and downs of treatment adherence
At MSF's 'Blue House' clinic in Mathare, one of Nairobi's largest slums and home to an estimated 250,000 people, 70 percent of TB patients are co-infected with HIV.
TB treatment is based on the DOTS (Directly Observed Treatment Short-course) practice of monitoring people with TB to ensure that they take their medication every day. However, at Blue House MSF practises SAT (self-administered therapy), which emphasises making patients aware of the benefits of taking their drugs daily and the consequences of not doing so.
"The method of educating the patient works better than one of control," said Genevier.
Monika Juma is one of four Blue House patients on the difficult two-year MDR drug regimen; she has been on the treatment for one-and-a-half months. "I live forty minutes walk away from the Blue House and I have to come in the morning and evening for treatment," she said.
Every morning she receives an injection, takes a sachet of medicine with acidic juice, and 16 tablets. In the afternoon she returns for a further five tablets and another sachet. Juma is also HIV-positive and takes antiretroviral (ARV) drugs. Her daughter and granddaughter, 5, also have TB. Although the doctors suspect that her granddaughter may have MDR-TB, she has not produced a sputum sample confirming this.
Despite the complexity of the treatment, Juma has not defaulted - she is well aware of the consequences of missing a dose of her medication, and has experienced minimal side effects.
The Kenyan government does not provide treatment for MDR-TB, which is 300 times more expensive than the standard TB treatment: a course of TB treatment costs about US$20, while the MDR drug regimen costs an estimated $6,000. Muthama, of the national TB control programme, said the government was working to curb MDR-TB.
"We have treatment centres where we are monitoring treatment as well as watching the patients. As many patients have to walk, we have increased the number of treatment centres to 1,800," he said. "The patients are tested after one-and-a-half months to see if they are responding well, and from here we should be able to see if people have resistant strains."
Health workers and activists are worried, because unless MDR-TB is halted, Kenya could succumb to more virulent strains of TB similar to the extremely drug-resistant TB detected in South Africa, where it has led to the death of more than 200 people.
Kenya is ranked 10th on the United Nations World Health Organisation's list of 22 countries that bear 80 percent of the world's TB burden.
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This report is part of a PlusNews In-depth: 'The New face of TB: Drug Resistance and HIV'