Studies on asymptomatic bacteriuria in children with sickle cell anaemia are very scanty. However, in this study, the prevalence of asymptomatic bacteriuria in children with sickle cell anemia is 6% and is comparable with the result obtained from Lagos by Ajasin et al  who documented 5.8%. This is also comparable to 5.3% documented by Vanessa et al  in adult sickle cell patients in Kingston, Jamaica. The proportion of children with sickle cell anemia who had significant bacteriuria in the current study is quite high when compared with the prevalence (2%) among children with normal haemoglobin genotype. At same time it is higher than the figures obtained by Abdulrahman  in Kaduna, North West, Nigeria and Okafor  in Enugu, South East, Nigeria among children with normal haemoglobin with prevalence of 1% and 2.1% respectively. The current study further supports the greater susceptibility of children with sickle cell anemia to urinary tract infection (UTI) with a threefold increase in asymptomatic bacteriuria when compared to their normal haemoglobin genotype controls. This higher risk is due to the defect in urine concentrating and acidifying abilities of the kidneys of children with sickle cell anemia. This produces abnormally dilute urine which favours bacterial proliferation.
Of the children with sickle cell anemia who had significant bacteriuria in the current study, there were more females than males in a ratio of 5:1. This ratio agrees with that obtained by Tarry et al  and Ajasin et al  who documented ratios of 10:1 and 3:2 respectively though there were larger sample sizes in the latter studies. This higher risk in the females has been attributed to short course of the female urethra and its proximity to the anal region.
Escherichia coli, a Gram negative enterobacteria was isolated from two (33.3%) of the six subjects with asymptomatic bacteriuria while proteus spp, Staphylococcus albus, Streptococcus faecalis, Staphylococcus aureus constituted 16.7% each. Previous studies [9, 20–23] of asymptomatic bacteriuria both in HbSS and HbAA subjects have identified Gram negative organisms particularly Escherichia coli and Klebsiella species as the most prevalent pathogens causing UTI in children. The Gram negative organisms have also been implicated as the most common cause of symptomatic UTI both in children with sickle cell anemia[16, 24] and those with normal haemoglobin. The range of pathogens in the current study is similar to that reported by earlier workers [15, 19, 23] except that Klebsiella species, the second most commonly reported pathogen causing UTI was not isolated in the current study. Thus organisms like E.coli, Klebsiella species, Proteus species, Streptococcus faecalis and Staphylococcus aureus are frequently isolated in subjects with asymptomatic bacteriuria irrespective of haemoglobin genotype. In developed countries of the world, E. coli is responsible for 80-90% of all organisms isolated from the urinary tract of children with UTI. The frequency with which this organism causes UTI in the developing countries including Nigeria is low as organisms such as Staphylococcus aureus, Streptococcus faecalis and proteus species have larger representation of causative agents in UTI in these less developed countries, probably due to poor environmental and personal hygiene in these less developed countries. It also seems that sickle cell anemia has some effect in the pattern of distribution of the organisms responsible for UTI allowing a greater representation of some other organisms such as Proteus and staphylococcus species. This may be due to the general impairment of the immune system in patients with sickle cell anaemia. The organisms isolated from the two controls with positive culture were both Gram positive organisms. This is at variance with what was obtained by Okafor et al  in which Gram negative organisms accounted for 59% of the 17 cases of asymptomatic bacteriuria among pre-school children. This variance may be due to the smaller number of children enrolled as control in the current study.
The sensitivity of the isolated organisms indicates that most of the organisms were resistant to the older antibiotics such as cotrimoxazole, ampicillin, streptomycin and tetracycline (contraindicated in children less than 8 years) both in subjects and controls. This high resistance to the older antibiotics was also noted by other workers both within and outside the country [15, 23–25]. The reason for this high resistance may be due to self medication and/or sub-therapeutic (drug pressure) prescription by some health workers as well as poor drug compliance by some patients. It may also be due to intrinsic drug resistance developed by the pathogens.
Urinalysis in both subjects and controls indicated that the urine samples were acidic in all the children with asymptomatic bacteruria. It has been stated that children with sickle cell anaemia have urine acidifying defect but this has not been so in the current study. It may be that the kidneys of these subjects still retain their ability to acidify urine. Nitrite test was negative in all the children with asymptomatic bacteriuria and this may be due to the low sensitivity of this test in detecting bacteriuria as has been observed in a study Wammanda and coworkers .
The urine microscopy among the sickle cell anaemia patients showed pyuria ranging from 1-6/hpf but only one with significant bacteriuria had significant pyuria. The sensitivity and specificity of significant pyuria as a determinant of significant bacteriuria in centrifuged urine sample is 61% and 43% respectively . This relatively low sensitivity may explain the presence of significant pyuria in only one of the subjects with asymptomatic bacteriuria. Pyuria is an indication of active inflammation and in cases of asymptomatic bacteriuria as in the current study; significant pyuria may not be detected.
In view of the increased incidence of asymptomatic bacteriuria in children with sickle cell aaemia, it is therefore necessary to screen them for UTI in the clinics using at least the fast and economical tests for detecting bacteriuria such as nitrite and leukocyte esterase tests and that ciprofloxacin may be considered in the empirical treatment of UTI as this has been found to be safe in children .