EVALUATION OF THE EFFECT OF TEMPERATURE AND DURATION OF STORAGE ON DETECTION OF HIV ANTIBODIES IN DRIED BLOOD SPOT ON FILTER PAPER

Abstract

This study was conducted during the period between November, 2003 to March; 2004 to study the use of dried blood spot on filter paper for detection of HIV antibodies in venous blood samples using ELISA technique. The study was conducted in Khartoum Teaching Hospital AIDS unit. A total of 100 specimens from known AIDS patients randomly selected and 50 specimens from healthy control were collected on filter paper, and air dried. The collected specimens were subjected to various atmospheric conditions (temperature, etc...) and the effect of time, temperature and humidity, on the stability of antibodies was evaluated. Phosphate buffer saline eluates from dried spot on filter paper were tested for HIV antibodies. The results were then recorded and compared for the different conditions. The result showed that the the detection of HIV antibodies in eluate of whole blood impregnated filter paper strips continued to be stable for two months for all specimens stored in refrigerator, incubator at 37°C, and at room temperature. The specimens there after started to deteriorate and by 3 months all specimens revert negative. The result also showed that dried blood spot on filter paper remained stable for longer time at refrigerator than at room temperature and incubator. The result concluded that collection of blood on filter paper is simple to do, cheap and associated with lower risk of infection and loss or spoiling of specimen compared to the ordinary method of serum collection. Dried blood spot on filter paper are also easier to store and transport with minimum risk and cost.