Effects of Crude Oil Exposure on Rats Experimentally Infected with Trypanosoma brucei brucei

ABSTRACT

This study investigated the effect of exposure to crude oil on rats experimentally infected with Trypanosoma brucei brucei. Thirty (30) adult male albino rats weighing 165 ± 15.0g were used for the study. They were kept in metal cages in a fly-proof house and fed with proprietary rodent diet and given water ad libitum. The rats were divided into five groups (AE) of six rats each. Groups A and B represented the uninfected-unexposed and infectedunexposed controls respectively, whereas groups C, D and E were exposed orally to 0.1, 0.2 and 0.4 ml of crude oil respectively every alternate day for three weeks. All rats were inoculated intraperitoneally (ip) with 0.3 ml suspension of a 10% washed sheep red blood cell (SRBC) and given a booster dose of SRBC seven days later. Groups B – E were later infected ip with Trypanosoma brucei brucei. Rectal temperature, packed cell volume (PCV), total and differential white blood cell (WBC) counts were monitored weekly. Parasitaemia was assayed daily while direct haemagglutination was evaluated weekly from the sixth week. In addition the serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) as well as the serum levels of urea and creatinine were estimated. Data generated was analysed by analysis of variance (ANOVA) using SPSS version 15 for Windows. Variant means were separated by Duncan’s multiple range test. The results of the study showed an average pre-patent period of 5 days for all T. brucei brucei infected rats, with peak parasitaemia observed for groups B, C and E on day 10 post infection and a second wave from day 12 post infection until day 14 after which all the rats were humanely sacrificed. The parasitaemia of group D on the other hand peaked on day 11 post infection without remission. All T. brucei brucei infected rats (groups B, C, D and E) showed a significant increase (p