Bacterial Aetiology of Pyrexia of Unknown Origin in Khartoum Educational Hospital

Abstract

The clinical phenomenon of pyrexia of unknown origin (PUO) was defined in 1961 as an illness persisting for three weeks or longer, with episodes of fever greater than 38ºC and with no diagnosis reached after one week of routine hospital investigations. This study was carried out in Khartoum Educational Hospital, from October 2006 to April 2007 to determine the bacterial aetiology of pyrexia of unknown origin .Two hundred blood samples were collected from two hundred PUO patients for culture and serological tests. Fifteen ml of blood were collected from every patient. These 15 ml of blood were divided into: 10 ml for culture, 2.5ml for serology and 2.5 ml for blood films and ESR tests. This study aimed at the isolation and identification of bacterial aetiology and to determine their susceptibility to certain antibacterial agents. Of the 200 blood cultures, 39 (19.5%) were infected and 161 (80.5%) were noninfected. The percentages of isolated microorganisms were (49%) for Staphylococcus aureus followed by Pseudomonas aeruginosa (15.4%), Salmonella typhi (10.3%), Proteus mirabilis (8%), Candida albicans (8%), Escherichia coli (5.1%), and Klebsiella pneumoniae (5.1%). Grampositive bacteria represented 49% of total isolated organisms while Gram- negative bacteria represented 43.5% of total bacterial isolates. The most active drug against Gram- positive cocci was vancomycin followed XII by gentamicin and cephalexin. All Gram- negative bacilli (except Ps. aeruginosa) were 100% susceptible to imipenem, ciprofloxacin, ceftazidime and ceftriaxone. All Pseudomonas aeruginosa strains were 100% susceptible to gentamicin, amikacin, imipenem, piperacillin and ceftazidime and 83 of them were susceptible to ciprofloxacin, aztereonam, ceftriaxone . Serological tests were done for the 200 patients' sera. They included Widal test for typhoid (enteric) fever (11.5%), and Widal –like test for brucellosis (4%), rheumatoid factor (1%), antistreptolysin O (ASO) antibodies test (4.5%), and venereal diseases research laboratory (VDRL) test (1%). Other investigations included thin and thick blood films for malaria parasite, the percentage of which was (8%), and erythrocyte sedimentation rate (ESR) was elevated in (45.5%) of the cases. None of the S. aureus strains was resistant to vancomycin . None of the Gram-negative bacteria was resistant to ceftazidime or imipenem.