Aerobacteriology of laboratories and offices: Evidence of high risk exposure to immune complex formation in Nigeria

To evaluate the air bacterial load especially in high environmentally polluted areas. The air bacterial load of 5 laboratories and 2 offices in Anambra State were sampled, using settled plate (sedimentation) method. All the laboratories showed average of 44-55 colony forming units (CFU) within 15 minutes. Both aerobic and anaerobic bacteria were isolated. The predominant bacteria were: Micrococcus, Diptheroids, Staphylococcus species, Bacillus species, Corynebacterium diphtheriae (C. diphtheriae), Clostridium species and Propionibacterium amongst other variety of bacteria isolated. Office with air-conditioning system gave a total of 34 CFU out of 74 CFU shown in the two 2 offices, while the office without air-conditioning system gave forty (40) colonies. It was found that the laboratories with more number of people, with frequent movement were more air loaded with bacteria than those with less number of people. All the areas sampled, contain significantly high number of colony forming units (CFU) than 3 CFU found in standard clean room P <0.001. It is an evidence of high risk of persistent infections and subsequent immune complex formation.