Efficacy of disinfectants on control and clinical bacteria strains at a zonal referral hospital in Mwanza, Tanzania: a cross sectional hospital-based study

Abstract

Contaminated-hospital surfaces are an important source of pathogenic bacteria causing health-care associated infection (HCAIs). Monitoring the performance of disinfectants that are routinely used to clean hospital surfaces is critical for prevention and control of HCAIs. Nevertheless, the evaluation of the performance of disinfectants and their efficacy are not routinely practiced in most resource-limited countries. This study was designed to determine the efficacy of sodium dichloroisocyanurate (NaDCC) and chloroxylenol against American Type Culture Collection (ATCC) and their respective multidrug resistant (MDR) strains causing neonatal sepsis at a zonal referral hospital in Mwanza, Tanzania. Four ATCC (n = 4) and their respective MDR strains of Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were used. The suspension test was used with contact time of 1, 5 and 10 min with starting concentration of 10⁵ bacterial colony forming unit per milliliters (CFU/mL). The log₁₀ reduction value at specified bacteria-disinfectant contact time was used to assess the efficacy of 0.5%NaDCC and 4.8% chloroxylenol in-use and freshly prepared solutions. In-use 0.5%NaDCC demonstrated poor log reduction (˂ 5log) against MDR-clinical isolates. Freshly laboratory prepared 0.5% NaDCC had 100% microbial reduction at 1, 5 and 10 min of both ATCC and MDR strains up to 48 h after preparation when compared with freshly prepared 4.8% chloroxylenol (˂ 5log). Freshly, prepared 0.5% NaDCC should be used in health-care facilities for effective disinfection practices.