Objectives: To determine the prevalence of bacteria that could cause diarrhoea in stool specimens of individuals with and without diarrhoea in both urban and rural areas of Nigeria. To ascertain the antibiotic susceptibilities of the bacterial diarrhoeagenic agents isolated. To document the predominant signs and symptoms associated with the various bacterial agents of diarrhoea.
Design: Prospective study.
Setting: Patients/individuals attending government and private clinics in Lagos, Edo and Cross-River States of Nigeria.
Subjects: A total of 1,200 stool samples were collected from patients with diarrhoea. Another total of 1,200 stool specimens were obtained from controls.
Results: For diarrhoea cases in urban areas Campylobacter spp. were more predominant (28%) and were followed by enteropathogenic Escherichia coli (EPEC) (28%) whereas in rural areas, EPEC were the most commonly isolated bacteria (18%), closely followed by Salmonella spp. (16%). Controls had a similar distribution pattern. Higher rates of isolation of these enteric bacteria were recorded among diarrhoea cases than in controls (p < 0.05). Diarrhoea due to Vibrio, Yersinia, Aeromonas, Plesiomonas and EPEC was mainly watery whereas it mainly consisted of blood/mucus for Shigella and Salmonella. All were associated with abdominal pain and fever. Results presented also indicate that over 80% of Shigella species, Salmonella, EPEC and P. shigelloides were susceptible to nalidixic acid and nitrofurantoin. Virtually all the enteropathogens were resistant to commonly used antibiotics such ampicillin, erythromycin, tetracyclines and streptomycin.
Conclusion: Results show that distributional patterns of bacterial agents of diarrhoea may vary in urban and rural areas and have revealed the effectiveness of nalidixic acid, gentamicin and nitrofurantoin, in that order, against these enteropathogens.