Tuberculosis and HIV Coinfection in Two Districts in Somaliland

Abstract

Tutkimuksessa selvitettiin immuunikatoviruksen (HIV) yleisyyttä tuberkuloosipotilailla Somalimaassa ja arvioitiin HIV-infektion vaikutusta taudinkulkuun.

HIV on tärkein kansanterveydellinen ongelma Afrikassa ja se sen kantajilla on suuri riski sairastua tuberkuloosiin. Tutkimus toteutettiin kahdessa suuressa tuberkuloosisairaalassa Boramassa ja Hargeisassa vuosina 2003-2004. Aineiston muodostivat 800 näissä sairaaloissa hoidettua tuberkuloosipotilasta. Suurimmalla osalla potilaista (82%) oli keuhkotuberkuloosi. Potilaista 11% oli HIV-positiivisia. Värjäysnegatiivinen tuberkuloosi oli yleisempää HIV-infektion kantajilla (56%) kuin muilla potilailla (24%). Kolmen kuukauden hoidon jälkeen edelleen värjäyspositiivisia oli 12% HIV-infektoituneista ja 6% muista potilaista. Hoidon lopussa 38% HIV-positiivisista oli parantunut tuberkuloosista, mikä ole selvästi vähemmän kuin muista potilaista (73%).

Tulokset osoittavat HIV-infektion yleistyneen tuberkuloosipotilailla myös Somalimaassa, vaikka tiulanne on edelleen selvästi parempi kuin monissa muissa Saharan eteläpuolisen Afrikan maissa. HIV-potilaiden tuberkuloosi on erityinen haaste sillä hoitotulokset ovat huonompia kuin muilla potilailla.

The objectives of the study were to assess human immunodeficiency virus (HIV) prevalence among patients with tuberculosis in Somaliland and to analyse differences in disease characteristics, smear conversion and treatment outcome between HIV seropositive and seronegative tuberculosis (TB) patients.

The study was conducted in two main TB centres in Somaliland, Borama and Hargeisa from January 2003 to August 2004. A total of 839 patients treated in these centres were enrolled. Thirty-one patients withdrew from the study and 8 cases were excluded for not fulfilling the study criteria. Data on HIV serological testing and follow up of sputum smear conversions and treatment outcome was obtained for 800 TB patients. Age groups 15 24 and 25 34 years comprised 66% of the TB patients. Age distribution was similar among men and women. The majority of the patients were residents of Borama and Hargeisa districts. Of the patients 81.5% (95% 78.4 83.8) had pulmonary and 18.5% (95% CI 16.2 21.6) extrapulmonary tuberculosis. Of the patients with pulmonary disease, 73% (95%CI 69.5 76.3) were smear-positive cases and 27% (95% CI 23.6 30.4) smear-negative. Hargeisa TB centre had a higher proportion of pulmonary smear-negative cases compared to Borama (34% versus 14%). Among 800 TB patients tested for HIV infection, 10.9% (95% CI 8.9 13.2) were HIV seropositive. In Borama, the HIV seroprevalence was 14.5% (95% 10.9 19.0) and in Hargeisa 8.8% (95% CI 6.6 11.6). Among 536 men and 264 women, HIV prevalence was 11.1% (95% CI 8.8 14.1) versus 10.2% (95% CI 7.1 14.1). Occupation and marital status were also associated with HIV infection.

The disease characteristics among the 713 HIV seronegative TB patients showed that 81.5% (95% CI 78.4 84.1) were pulmonary and 18.5% (95% CI 15.8 21.5) were extrapulmonary, while the corresponding figures among the 87 HIV seropositive patients were 79% (95% CI 69.6 86.4) and 21% (95% CI 13.5 30.3). Among the 581 HIV seronegative pulmonary TB patients, 76% (95% CI 72.9 79.8) were smearpositive and 24% (95% CI 20.1 27.0) smear-negative. Among the 68 HIV seropositive pulmonary TB patients, 44% (95% CI 32.4 55.2) had pulmonary smear positive disease and 56% (95% CI 44.7 67.5) pulmonary smear-negative TB.

Smear results at 5/6 months of TB treatment were obtained from 411 TB patients with smear conversion in 97% (95% CI 94.6 98.2). Treatment outcome was obtained from 800 TB patients and among them 50% (95% CI 46.2 53.2) were cured, 31% (95% 7 CI 28.0 34.4) completed treatment, 4.5% (95% CI 3.2 6.1) died, 2.4% (95% CI 1.0 2.9) failed, 2.5% (95% CI 1.6 3.8) defaulted, 4.4% (95% CI 3.1 6.0) transferred and 6% (95% CI 4.5 7.8) could not be evaluated.

No smear conversion was reached at 2/3 months of TB treatment for 12% of the HIV seropositive and 6% of the seronegative TB cases (odds ratio, OR 1.9, 95% CI 0.43 7.38). No difference was observed between HIV seropositive and HIV seronegative TB in smear results at 5/6 months of TB treatment, with failure rates of 4% versus 3% (OR 1.3, 95% CI 0.46 9.75). Treatment failure rates among HIV smearnegative and HIV smear-positive TB were 62% versus 27%. HIV smear-negative TB patients had more frequent failures (OR 4.44, 95% CI 1.36 14.96).

HIV seroprevalence among the TB patients in Somaliland has increased. The national prevalence among TB patients was 4.7% in 1999, while the seroprevalence in the current study was 10.9%. The figures of Borama TB centre were 10% in 1999 and 14.5% in 2003. In Hargeisa, seroprevalence increased from 7% to 8.8%. No difference was found between HIV seropositive and seronegative patients in disease characteristics (pulmonary and extrapulmonary). The proportion of smear-negative TB was higher among the HIV seropositive. The treatment outcome was poorer among the HIV seropositive patients. It is recommended to start sentinel sites for HIV surveillance in the TB centres.