The reduction of HIV transfusion risk in southern Brazil in the 1990s.

A retrospective study of blood donor records was undertaken to obtain risk estimates for transfusing HIV-contaminated blood due to an infectious window period in a large blood bank in the south of Brazil in the 1990s. An incidence/window period model was used to estimate HIV incidence and risk of seroconversion among 11 286 repeat donors with 8917 person-years of follow-up. Separate estimates were calculated for the periods of 1991-94, 1995-96 and 1997-99. Although the residual risk of HIV-positive transfusion decreased from 1 : 5000 in 1991-94 and 1 : 3794 in 1995-96 to 1 : 48 777 in 1997-99, this is still almost 10 times higher than in developed countries. The risk reduction is likely to have resulted from improved donor selection. Despite a 10-fold reduction in the risk of transfusing HIV-contaminated blood because of the screening test's failure to detect the virus during the infectious window period in the 1990s, additional measures are urgently needed to reduce the risk further. To this end, PCR screening of pooled blood donations might be considered in areas of high HIV prevalence when justified by cost-effectiveness calculations.

Residual transfusion risk for hepatitis B and C in southern Brazil, 1991-99.

A retrospective study of 139188 blood donor records for the period 1991-99 was conducted in the largest blood bank in the federal state of Santa Catarina, in southern Brazil. The incidence/window method, based on 11286 repeat donors with 8917 person-years of follow-up, was used to estimate the residual risk for transfusing hepatitis B and C due to infectious window periods for early, mid and late years of the decade. The residual risk for transfusing HBsAg contaminated blood decreased almost three times over the 1990 decade but still remains very high at 1 : 2077 (95% confidence limits 1 : 1075-1 : 4624), with a corresponding incidence of 3.00 (1.35-5.77) per 1000 person-years. Similarly, although residual risk for hepatitis C was reduced more than 30 times in late 1990s, compared with the earlier period, the risk of 1 : 13721 (1 : 7102-1 : 30820) and corresponding incidence of 0.51 (0.23-0.99) per 1000 person-years are still very high compared to developed countries. In addition to vaccination against hepatitis B and health promotion efforts aimed at reduction of hepatitis transmission, special measures such as PCR screening of pooled blood donations might be needed to rapidly achieve a further residual risk reduction in high prevalence areas.

HIV seroprevalence among blood donors in southern Brazil in the decade of 1990.

The objective of this study was to establish the time trend in HIV seroprevalence among blood donors to a large blood bank in southern Brazil during the decade of 1990, and compare it to other data sources from the same region. To this end, a retrospective study of blood donor records in HEMOSC (Center of Hematology and Hemotherapy of Santa Catarina), federal state of Santa Catarina, Brazil, was conducted for the period 1991 through 1999. Annual seroprevalence of HIV among blood donors and its time trend for the entire period were calculated. The HIV seropositive fraction doubled every 3 years, reaching 4 new cases per 1,000 donors per year by the end of the decade, or roughly twice the national average. The increase occurred particularly among female blood donors, those over 46 years of age, and those residing in the Florianópolis metropolitan area. We conclude that, in the decade of 1990, the frequency of HIV in southern Brazil increased in the population seeking to donate blood. Possible reasons for this increase include an increased use of blood donation as a means to obtain HIV testing or increased transmission among low risk populations. The effect of increased transfusion risk of HIV transmission requires urgent attention.

The use and cost of hospital services by London AIDS patients with different AIDS defining conditions.

BACKGROUND: Contracting for HIV service provision is now an established part of the National Health Service commissioning process. AIDS is a heterogeneous condition, comprising various opportunistic illnesses which require different services and which have different resource implications. This study describes the use of hospital services and associated costs for the management of different AIDS defining conditions. METHOD: A retrospective case-notes analysis was performed, of 335 AIDS patients treated at St Mary's Hospital, London, between 1 January 1983 and 30 September 1989, as well as a costing exercise of 37 clinical departments to calculate HIV-related costs. RESULTS: Mean age at time of AIDS diagnosis for these predominantly homosexual men was 38 years. Use of services varied, as did associated costs-from 8163 pounds per patient-year for patients with Constitutional Disease to 42,124 pounds for those with Cytomegalovirus Disease Most diagnostic categories showed a shift over the study period from an in-patient- to an out-patient-based service. Patients diagnosed after 1987 had overall lower costs per patient-year compared with those diagnosed before 1987: whereas out-patient costs for most groups had increased, in-patient expenditure decreased. For most categories, in-patient care costs and out-patient drugs prescribed provided the greatest proportion of total costs. Average costs per in-patient day ranged from 334 pounds to 433 pounds, and average costs per out-patient visit ranged from 99 pounds to 411 pounds for different AIDS defining conditions. CONCLUSIONS: Different opportunistic illnesses of symptomatic HIV disease have different treatment and resource implications. Casemix will need to be taken into consideration when contracting for HIV services, including extra-contractual referrals.

Survival and the use and costs of hospital services for London AIDS patients treated with AZT.

The aim of this study was to evaluate the survival patterns and use and cost of hospital services of AIDS patients treated with azidothymidine (AZT) at St Mary's Hospital, London. A retrospective analysis of inpatient and outpatient case notes was performed, as was a survey of HIV-related care costs in 37 clinical departments. Of the 183 AIDS patients managed between 1 January 1987 and 30 September 1989, 132 were treated with AZt and 51 without AZT. Mean age at time of AIDS diagnosis for these predominantly homosexual men was 37.5 years for those treated with AZT compared with 40.7 years for those not on AZT. Median survival time from date of AIDS diagnosis was significantly longer for patients treated with AZT compared with those not treated with AZT (23 vs 13.5 months, P = 0.0004). The interval from diagnosis of HIV infection to date of AIDS diagnosis did not differ significantly between groups. Inpatients and outpatients use of services was greater for those receiving AZT than for those who did not. Costs reflected this increase use of services and the costs for those treated with AZT were pounds 3061 per AIDS patient-year higher compared with AIDS patients not receiving AZT; 36% of this cost was directly attributable to the cost of AZT itself. The introduction of AZT into routine clinical practice seems to have been a cost-effective intervention though it has been associated with an increased use of hospital services and associated costs per AIDS patient-year as well as increases survival time from AIDS diagnosis.

Correlation between total and CD4 lymphocyte counts in HIV infection: not making the good an enemy of the not so perfect.

The aim of this study was to assess the correlation and average cost of total lymphocyte count compared with CD4 count as a broad estimate of immunosuppression in HIV-1 infected individuals. Spearman's partial rank correlation were calculated between total lymphocyte count, absolute CD4 count and CD4 per cent stratified by stage of HIV-1 infection for routinely collected samples. Data were collected prospectively from a T cell-subset register combined with clinical data obtained retrospectively from case notes of HIV-infected patients managed at St Mary's Hospital, London 1982-1991. Costing data were obtained through a survey of the departments of haematology and immunology (1989/90 prices). The correlation between 1534 paired absolute lymphocyte count and CD4 lymphocyte count was found to be high (R = 0.76). When analysed by stage of HIV infection, the correlation increased from R = 0.64 for asymptomatic patients, to R = 0.72 for patients with symptomatic non-AIDS HIV infection and R = 0.73 for AIDS patients. Correlations between absolute lymphocyte count and CD4 per cent were considerably weaker: R = 0.41 all paired counts; R = 0.32 for asymptomatic patients; R = 0.25 for symptomatic non-AIDS patients; R = 0.32 for AIDS patients. Average cost was pounds 8 per full blood count compared with pounds 38 per T-cell subset analysis. The high correlation between total and CD4 lymphocyte counts, especially for patients with symptomatic HIV disease, demonstrates the suitability of the use of total lymphocyte count in the absence of CD4 counts. Given the considerably lower prices of total lymphocyte counts compared with T-cell subset analysis, this is particularly relevant for developing countries.