Just over 80% of HIV-positive patients co-infected with tuberculosis (TB) complete their full course of TB treatment, according to an audit presented to the fifteenth annual conference of the British HIV Association in Liverpool. This rate of treatment completion is below the 85% target set by the UK’s Chief Medical Officer. About 50% of patients received treatment with a standard and recommended regimen of tuberculosis drugs.
The British HIV Association published guidelines for the treatment of TB in HIV-positive individuals in 2005. These guidelines are currently being updated. Between October 2007 and April 2008 an audit was conducted to assess adherence to these guidelines. A total of 124 HIV centres and 18 TB clinics responded. The investigators were disappointed by the low response rate by TB clinics.
Data were available on 236 HIV/TB co-infected patients.
Consistent with guidelines, few centres were screening patients newly diagnosed with HIV for infection with TB. Clinics were more likely to do this if a patient was from a country with a high TB prevalence.
Specialist TB nurses provided support ay 63% of clinics with HIV nurse specialists providing support at 8% of clinics.
Most (53%) of the patients were female and 85% were born in a country with a high TB prevalence. Notification of TB infection was mentioned on only 36% of patients’ notes, but notification is thought to have been done in a further 48% of cases..
Contact tracing was reported for two-thirds of patients. The investigators speculate that for 9% of patients this was not undertaken because tests showed that the individuals did not have infectious TB. However, it was unclear in the remaining cases if this had been undertaken.
Regular HIV clinic attendance was reported for 78% of patients.
A third of patients first found out they had HIV at the time their TB was diagnosed and 55% already knew they had HIV.
Over two-thirds (69%) of patients had a CD4 cell count below 200 cells/mm3 at the time of their TB diagnosis; this included a substantial number of patients who were known to have HIV before their TB was detected.
Pulmonary TB was present in 58% of patients, with 59% also having extrapulmonary infection.
In two-thirds of patients, infection with TB was confirmed by culture, just meeting the Chief Medical Officer’s target of 65%. In a significant minority of patients, it took longer than the recommended 24 hours to obtain the results of sputum smear microscopy
Resistance to anti-TB drugs was present in eleven individuals at the time the infection was diagnosed. A further three individuals were later found to have resistance and resistance evolved in two patients during treatment.
Clinics reported that they expected 67% of patients to adhere well to treatment. Directly observed therapy was provided to a total of 29 patients at some point during their TB treatment.
The recommended duration of TB treatment is six months. This is extended to twelve months if the central nervous system is involved. Fewer than half (48%) received the recommended six months treatment (in most cases it was longer) and only 50% received the standard regimen of drugs.
Treatment was completed by 79% of patients, with 61% doing so without interruption. The Chief Medical Officer’s target for treatment completion is 85%.
Generally, the interval between the initiation of TB treatment and the starting of antiretroviral therapy was in accordance with guidelines. It is generally recommended that patients receiving TB treatment should receive antiretroviral therapy based on a non-nucleoside reverse transcriptase inhibitor (NNRTI) and this was the case in 80% of patients. However, 16% were taking therapy with a boosted protease inhibitor. Although this can involve a risk of interaction with anti-TB drug, it was appropriately managed in all cases. A small minority of patients initiated HIV therapy with a regimen that only consisted of nucleoside reverse transcriptase inhibitors (NRTIs), a combination that is not recommended.
An immune reconstitution inflammatory syndrome (IRIS) was diagnosed in 14% of patients and most received treatment with steroids. A further 14% of patients reported a worsening of the symptoms of TB after starting HIV treatment, but it was unclear if this was due to an IRIS.
The presenting investigator concluded by expressing concern that HIV tests were still not routine for all patients diagnosed with TB. He added that notification of TB was a statutory requirement but was not happening in all cases and that the rate of treatment completion was not quite on target.
Backx M Audit of management of tuberculosis in HIV co-infected patients. Fifteenth Annual Conference of the British HIV Association, Liverpool, 2009.