The Effectiveness of Ultraviolet-C (UV-C) versus Aerosolized Hydrogen Peroxide (aHP) in ICU Terminal Disinfection

BACKGROUND

According to the Centers for Disease Control and Prevention, 10% of patients with healthcare-acquired infections (HAIs) died during their hospitalisation in 2015. Thus, the reduction in HAI prevalence is critical. One strategy to achieve this is the adequate disinfection of patient rooms within the hospital.

AIM

To compare the effectiveness of an Ultraviolet-C room sanitizer against that of an aerosolized hydrogen peroxide device in eliminating selected healthcare-associated (HA) pathogens and other HA-organisms in an ICU setting.

METHODS

The disinfection systems were tested on the following organisms: meticillin-resistant Staphylococcus aureus, extended-spectrum beta-lactamase-producing Klebsiella pneumoniae, carbapenem-resistant K. pneumoniae, vancomycin-resistant enterococci, multidrug-resistant Acinetobacter baumannii, and Candida auris. Media plates with known densities of each organism and placed at preselected regions within an ICU room. The mean kill rate was determined for each organism. Additionally, swabs were taken from five high-touch areas from different ICU rooms prior to manual cleaning, following manual cleaning, and following each disinfection method in order to compare their effectiveness.

FINDINGS

The UV-C device achieved a 96.75% mean microbial reduction in non-shaded areas. It was significantly less effective in the shaded regions. The aHP system achieved a mean kill rate of 50.71% for all areas. The swab results revealed that 15% of manually cleaned surfaces still harboured a microbial load, which was eradicated after use of either no-touch disinfection system.

CONCLUSION

This study presents the notable differences between two no-touch disinfection methods, highlights their effectiveness and advocates for their incorporation alongside a manual cleaning regimen.

Horizontal transfer of OXA-23-carbapenemase-producing Acinetobacter species in intensive care units at an academic complex hospital, Durban, KwaZulu-Natal, South Africa

Introduction: Carbapenemase production is an important mechanism of carbapenem resistance in Acinetobacter species. This study investigated the presence of the carbapenem-hydrolysing class D β–lactamase- encoding genes, blaOXA-23 and blaOXA-58, and their association with the spread of multidrug-resistant (MDR) Acinetobacter species in intensive care units at an academic hospital. Method: Forty-four MDR Acinetobacter species were confirmed using VITEK®2 and Epsilometer tests. The blaOXA-23 and blaOXA-58 genes were detected by polymerase chain reaction (PCR) in twenty-four selected isolates. The blaOXA-23 amplicons were sequenced and compared to the GenBank database. Genotypic relatedness of isolates was determined by pulsed field gel electrophoresis (PFGE). Clinical and laboratory data were analysed. Results: Among the twenty-four isolates, eighteen were carbapenem resistant and six were sensitive. The blaOXA-23 gene, but not blaOXA-58, was detected in the eighteen resistant strains. The blaOXA-23 amplicons showed 100% identity with the GenBank database of blaOXA-23. The MICs of carbapenems against Acinetobacter species carrying the blaOXA-23 gene were 8 to 16 μg/ml. Genetic relatedness was evident among isolates of seven pairs from fourteen patients. Of these patients, twelve were in the same ICUs and two were adjacent to another ICU during the same hospitalisation period. Conclusion: The selected MDR Acinetobacter species carried the blaOXA-23 gene responsible for resistance to carbapenems, while molecular and clinical data analysis suggested horizontal transmission in ICUs. In addition, the PFGE typing of a diverse collection of MDR Acinetobacter species clones showed that isolates were related to no more than two patients, suggesting that no outbreak had occurred.

Treatment Outcomes in CML Patients Treated With Tyrosine Kinase Inhibitors at a Tertiary Teaching Hospital in South Africa

BACKGROUND

Chronic myeloid leukemia (CML) has become one of the most treatable hematologic neoplasms since the advent of the tyrosine kinase inhibitors (TKIs), but it was not known if similar treatment outcomes could be achieved in a resource-limited country. We tested the hypothesis that, despite challenges to access to second-generation TKIs, excellent responses could be replicated in the setting of limited resources.

PATIENTS AND METHODS

Records of 58 patients with newly diagnosed CML in the chronic phase treated with TKIs at a tertiary teaching hospital in Cape Town, South Africa between 2003 and 2012 were reviewed and assessed according to European LeukemiaNet (ELN) criteria.

RESULTS

After a median follow-up of 60.5 months, progression-free survival at 60 and 96 months was 79.98% and 68.4%, respectively. Overall survival at 60 and 96 months was 92.9% and 83.6%, respectively. Progression to blast phase at 60 months was associated with poorer survival (P = .0002) but progression to accelerated phase was not (P = .1456). Attainment of a complete cytogenetic response at 12 months (P = .28) or major molecular response at 18 months (P = .268) did not have prognostic significance.

CONCLUSION

Despite delays in achievement of the target responses defined according to ELN criteria, the use of imatinib mesylate as a first-line treatment can still result in treatment outcomes comparable with those in developed countries. These data suggest opportunities for improvement and success might be even greater with uninterrupted access to second-generation or newer TKIs.

Molecular characterisation of gastrointestinal stromal tumours in a South African population

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the digestive tract. Pathogenesis is linked to activating mutations identified in two proto-oncogenes, v-kit Hardy/Zuckerman 4 feline sarcoma viral oncogene homologue KIT (KIT) and the platelet-derived growth factor α (PDGFRα). In addition, these mutations affect response to treatment with tyrosine kinase inhibitors. In the present study, we report on the molecular characterisation of GISTs in the South African population. Tumour DNA was extracted from 46 GIST samples, followed by cycle sequencing of KIT exons 11, 13 and 17 and PDGFRα exons 12, 14 and 18. Fragment length analysis was used to detect a 6-bp duplication in KIT exon 9. Wild-type duplications were analysed further by PCR and sequencing of additional KIT and PDGFRα exons was performed. Overall, 78.3% of the samples had a mutation in KIT or PDGFRα. Of these, mutations were detected in KIT exon 11 (88.9%), PDGFRα exon 18 (8.3%) and KIT exon 9 (2.8%). Mutations varied from simple substitutions and duplications to large deletions (some with nucleotide insertions) resulting in missense mutations. In addition, seven single nucleotide polymorphisms were detected in 17 patients, one of which appears novel. The incidence of mutations in KIT exon 11 and PDGFRα exon 18 is consistent with the literature, however, the low incidence of KIT exon 9 mutations detected was unexpected. In contrast to previous western and Asian studies, this mutation appears to be rare in the South African population. The present study contributes to the molecular understanding of GISTs in the South African population.