CROI: Rapid scale-up of HIV treatment in Zambia

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Zambia’s Ministry of Health reported impressive results from its HIV treatment scale-up programme at the Thirteenth Conference on Retroviruses and Opportunistic Infections, held this week in Denver.

By the end of 2005 a total of 22,121 adults and children in the Lusaka area had begun antiretroviral treatment, predominantly initiated through nurse and clinical officer-led clinics, and a total of 36,566 patients had been enrolled into HIV care.

Almost half of the people who began treatment did so in the second half of 2005, indicating that treatment enrolment accelerated dramatically in the second year of the programme.

Glossary

WHO stage

A simplified system to describe four clinical stages of HIV-related disease, based on clinical parameters (symptoms, weight loss and different opportunistic infections) rather than decreasing CD4 cell count. Stage I is asymptomatic, stage II mild symptoms, stage III advanced symptoms and stage IV severe symptoms (an AIDS diagnosis).

multivariate analysis

An extension of multivariable analysis that is used to model two or more outcomes at the same time.

body mass index (BMI)

Body mass index, or BMI, is a measure of body size. It combines a person's weight with their height. The BMI gives an idea of whether a person has the correct weight for their height. Below 18.5 is considered underweight; between 18.5 and 25 is normal; between 25 and 30 is overweight; and over 30 is obese. Many BMI calculators can be found on the internet.

inter-quartile range

The spread of values, from the smallest to the largest. The inter-quartile range (IQR) only includes the middle 50% of values and measures the degree of spread of the most common values.

hazard

Expresses the risk that, during one very short moment in time, a person will experience an event, given that they have not already done so.

However Zambia still has a long way to go. The Zambian Ministry of Health estimates that 56,000 adults in the Lusaka area need treatment already, and a further 28,000 people will become eligible for antiretroviral treatment each year.

Responses good even among most advanced patients

Even amongst patients with the most advanced HIV disease, those with baseline CD4 cell counts below 50 cells/mm3, more than 90% of patients followed for 15 months (460 days) were still alive. In comparison all the patients with CD4 cell counts below 50 enrolled in the programme for 15 months who did not receive any antiretroviral therapy (largely a historical control group enrolled before the availability of free ART) were dead after 15 months.

Clinical care at all sites was standardised according to national guidelines. Treatment initiation was guided by World Health Organization (WHO) clinical staging and CD4 cell count. The standard first-line drug regimen consisted of AZT (zidovudine, Retrovir) or d4T (stavudine, Zerit), plus 3TC (lamivudine, Epivir), plus nevirapine (Viramune) or efavirenz (Sustiva). 92% of patients received nevirapine-based regimens; efavirenz was given only where concomitant TB treatment was necessary.

Data were collected using a computerised record system and standardised chart reviews.

Among the 11,074 individuals who started treatment by August 2005, 61% (6,806) were women. Nearly three-quarters (8,009 patients, or 73%) had WHO stage III or IV disease. The mean CD4 cell count was 131 cells/mm3 (interquartile range [IQR] 52-182); viral load data were not reported. The mean body mass index was 21.3 (IQR 17.9-22.4).

Over 81,248 patient-months of follow-up, 1,269 participants died, for a crude death-rate of 0.016 deaths/patient-month). About one-half (53%) of these deaths occurred within 60 days of enrolment into the program, and 43% were among patients with baseline CD4 counts of 50 or fewer cells/mm3.

Multivariate analysis showed the following hazard ratios for death among those who started antiretroviral therapy:

  • WHO stage 3 (reference stage 1 and 2 combined): 2.0
  • WHO stage 4: 3.3
  • 50 – 200 CD4 cells (reference CD4 > 200): 1.5
  • 200): 2.1
  • Body mass index
  • Haemoglobin
  • Adherence
  • TB: 1.0

Nearly 12,000 individuals were followed for at least six months to assess immunological response. Among the 8,284 patients who started antiretroviral therapy, mean CD4 count increased by 61 cells/mm3 at six months and by 85 cells/mm3 at twelve months, compared with only a 5 cells/mm3 increase at six months and a 23 cells/mm3 decrease as twelve months among the 3,570 participants who did not receive treatment (p

References

Sinkala M et al. Rapid scale-up of antiretroviral services in Zambia: 1-year clinical and immunologic outcomes. Thirteenth Conference on Retroviruses and Opportunistic Infections, Denver, abstract 64, 2006.