[Peru's experience with a national blood banking program]

High endemicity of human T-cell lymphotropic virus type 1 among pregnant women in peru

Human T-cell lymphotropic virus type 1(HTLV-1) is associated with adult T-cell leukemia, tropical spastic paraparesis, and other immune-mediated diseases. There are reports of groups with high prevalences of HTLV-1 infection in Peru, but there is limited knowledge of the epidemiology of infection or which routes of infection are most important. We studied 2,492 women presenting to a large maternity hospital in Lima for prenatal, delivery, or abortion services. HTLV-1 seropositivity was confirmed in 42 women (1.7%; 95% confidence interval, 1.2-2.2). Seroprevalence increased with age but did not vary by region of birth or recency of migration to Lima. Age greater than 30 years and sexual intercourse before 20 years of age were strongly and independently associated with infection. History of abortion and history of transfusion were of borderline significance. Women whose male partner had a characteristic that might be a marker for risk of sexually transmitted infections were also more likely to be infected. HTLV-1 is common among Peruvians throughout the country and is maintained by a low level of neonatally acquired infection that is amplified by sexual transmission. In addition to screening of the blood supply, instituted in 1997, programs designed to reduce neonatal and sexual transmission should be effective.

Improving the safety of the blood supply in Ecuador through external performance evaluation of serological screening of blood donors

BACKGROUND

The Ecuadorian National Blood System collects approximately 100 000 units of blood per year. Screening for infectious agents is conducted by 23 autonomous blood services using different methodologies and reagents.

OBJECTIVES

To evaluate the performance of serology testing by laboratories of the Ecuadorian National Blood Bank System.

STUDY DESIGN

Four proficiency panels were distributed between April 2003 and December 2004 containing samples that were characterized as either reactive or non-reactive for hepatitis B surface antigen (HBsAg), antibodies against hepatitis C virus (HCV), and antibodies against human immunodeficiency virus (HIV). Laboratories were classified according to the volume of blood units processed per year, as small (<5000), medium (5000-12000) and large (>12000).

RESULTS

Large and medium blood services consistently obtained better results than small ones. All of the 37 anti-HIV antibody false negative results and all of the 20 HBsAg false negative results were reported by small laboratories. False negative results were associated with the use of rapid tests. Laboratories using rapid tests and certain lots of an enzyme-linked immunosorbent assay (ELISA) failed to detect HCV reactive sera in December 2004.

CONCLUSION

The high number of incorrect results in most small blood services indicates serious weaknesses in blood screening that require urgent corrective action. The National Blood System has implemented on-site audits, training, technical assistance, and increased oversight. The long-term proposal is to centralize blood testing in two large blood centers. The results presented here underline the importance of strengthening the regulatory framework and oversight in Ecuador and highlight the role of external performance evaluation programs for blood safety improvement.