Understanding the challenges to COVID-19 vaccines and treatment options, herd immunity and probability of reinfection

Unlike pandemics in the past, the outbreak of coronavirus disease 2019 (COVID-19), which rapidly spread worldwide, was met with a different approach to control and measures implemented across affected countries. The lack of understanding of the fundamental nature of the outbreak continues to make COVID-19 challenging to manage for both healthcare practitioners and the scientific community. Challenges to vaccine development and evaluation, current therapeutic options, convalescent plasma therapy, herd immunity, and the emergence of reinfection and new variants remain the major obstacles to combating COVID-19. This review discusses these challenges in the management of COVID-19 at length and highlights the mechanisms needed to provide better understanding of this pandemic.

Prevalence of Vancomycin-Resistant Enterococcus (VRE) in Poultry in Malaysia: The First Meta-Analysis and Systematic Review

Databases such as PubMed, Scopus and Google Scholar were searched. Data extraction and assessment of study protocol was done by two independent reviewers and the results were reviewed by a third. OpenMeta analyst and comprehensive meta-analysis (CMA) were used for the meta-analysis. The random effect model was used, publication bias and between-study heterogeneity was assessed. Seventeen studies were added to the final meta-analysis. Studies were sampled from 2000–2018 and of the 8684 isolates tested, 2824 were VRE. The pooled prevalence of VRE among poultry in Malaysia was estimated at 24.0% (95% CI; 16.7–33.1%; I² = 98.14%; p < 0.001). Between-study variability was high (t² = 0.788; heterogeneity I² = 98.14% with heterogeneity chi-square (Q) = 858.379, degrees of freedom (df) = 16, and p < 0.001). The funnel plot showed bias which was confirmed by Egger’s test and estimates from the leave-one-out forest plot did not affect the pooled prevalence. Pooled prevalence of VRE in chickens and ducks were 29.2% (CI = 18.8–42.5%) and 11.2%, CI = 9.0–14.0%) respectively. Enterococcus faecalis was reported most with more studies being reported in Peninsular Malaysia Central region and used antibiotic disc diffusion as detection method. Increased surveillance of VRE in poultry in Malaysia is required.

Genotypic variations of virulent genes in Enterococcus faecium and Enterococcus faecalis isolated from three hospitals in Malaysia

BACKGROUND

The genus Enterococcus is of increasing significance as a cause of nosocomial infections, and this trend is exacerbated by the development of antibiotic resistance.

OBJECTIVES

The aim of the present study was to estimate the potential virulence factors in enterococci and to ascertain their prevalence in Malaysian hospitals.

MATERIAL AND METHODS

The study comprised 222 enterococcal strains isolated from blood, urine, exudates, sputum, stool and body fluid. These strains were collected from patients staying in three referral hospitals in Malaysia. All isolates were identified to the species level, and their MIC of vancomycin was determined using E test strips. Specific primers were designed for detection of the five potential virulence genes (gelE, PAI, esp, ace, and sprE) by PCR assay.

RESULTS

Different patterns and frequency of virulence determinants were found for the E. faecalis and E. faecium isolates. E. faecalis isolates had more virulence determinants than E. faecium isolates. Clinical enterococcal isolates were found to possess more virulence determinants than enterococci isolated from faecal samples. The esp gene is significantly more common (p = 0.049) in vancomycin-resistant strains (85.7%) than in vancomycin-sensitive strains (44.2%). All of the vancomycin-resistant isolates were isolated from faecal samples. None of the classical virulence factors were found in 11% of enterococcal isolates, while all five virulence genes were found in 21% of enterococcal isolates.

CONCLUSIONS

All the virulence genes considered in this study were important in the pathogenesis of enterococcal infections and further studies including more virulence genes and epidemiological data will be necessary in order to analyze the association and role of virulence genes in the pathogencity of enterococci.

Methicillin-resistant Staphylococcus aureus nosocomial infection trends in Hospital Universiti Sains Malaysia during 2002-2007

BACKGROUND AND OBJECTIVES

Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen that causes severe morbidity and mortality in many hospitals worldwide. The aim of the present study was to assess the burden of MRSA nosocomial infection, its association with factors of interest, and its antimicrobial susceptibility.

METHODS

This was a retrospective analysis of a database of all S aureus that were cultured from patients admitted to the different wards of Hospital Universiti Sains Malaysia (HUSM) over a period of 6 years.

RESULTS

The MRSA infections rate was 10.0 per 1000 hospital admissions. The incidence density rate of MRSA infections during the study period was 1.8 per 1000 patient-days, with annual rates ranging from 0.95 to 3.47 per 1000 patient-days. Duration of hospitalization, previous antibiotic use, and bedside invasive procedures were significantly higher among MRSA than methicillin-sensitive S aureus patients (P>.05). The highest number of MRSA infections were found in orthopedic wards (25.3%), followed by surgical wards (18.2%) and intensive care units (ICUs) (16.4%). All MRSA isolates were resistant to erythromycin (98.0%), co-trimoxazole (94.0%) and gentamicin (92.0%). Clindamycin was the best antibiotic with only 6% resistance. All MRSA isolates were sensitive to vancomycin.

CONCLUSION

The rate of nosocomial MRSA infection per 1000 admissions was higher than that in other studies. The three factors associated most significantly with acquired MRSA infections included duration of hospitalization, antibiotic use, and bedside invasive procedures. This study confirmed that vancomycin-resistant S aureus has not yet been established in HUSM.