EVALUATION OF COLD CHAIN MONITORING IN KELANTAN, MALAYSIA

An analysis was carried out on a total of 883 cold chain monitor (CCM) cards, which had been attached to batches of poliomyelitis, measles, DPT(diphtheria, pertussis, tetanus) and hepatitis B vaccines, during t heir transport and storage from the central store in Kuala Lumpur to K elantan, a state in north-eastern Malaysia; 234 freeze watches attache d to hepatitis B vaccines were also analysed. The monitor cards and fr eeze watches were observed at six levels between the central store and the periphery during distribution of the vaccines, and a colour chang e in any of the four windows (A, B, C, D) on the CCM cards or the free ze watches was recorded. In addition, 33 unopened vials of oral poliov irus vaccine (OPV), collected from refrigerators in 29 health faciliti es in Kelantan, were tested for potency using the tissue culture infec tive dose 50 (TCID50) method; 14 of them (42%) did not meet the WHO cr iteria for potent vaccines. The results showed that at the final desti nation 13.4% of all cards remained white while a colour change to blue was observed in 65% in window A, 16.6% in window B, and 4.4% in windo w C; none had turned blue in window D indicating that the vaccine had not been subjected to temperatures greater than or equal to 34 degrees C for 2 hours. All but 2 of the 234 freeze watches had turned purple, which indicates exposure of the hepatitis B vaccines to temperatures below 0 degrees C. These results will assist health planners to correc t the weaknesses identified in the cold chain system.