METHODS: This was an observational study reviewing all confirmed ZIKV cases detected in Malaysia through the ZIKV clinical surveillance and Flavivirus laboratory surveillance between June 2015 and December 2017. All basic demographic characteristics, co-morbidities, clinical, laboratory and outcome data of the confirmed ZIKV cases were collected from the source documents.
RESULTS: Only eight out of 4043 cases tested positive for ZIKV infection during that period. The median age of infected patients was 48.6 years and majority was Chinese. Two of the subjects were pregnant. The median interval between the onset of disease and the first detection of ZIKV Ribonucleic Acid (RNA) in body fluid was 3 days. Six cases had ZIKV RNA detected in both serum and urine samples. Phylogenetic analysis suggests that isolates from the 7 cases of ZIKV infection came from two clusters, both of which were local circulating strains.
CONCLUSION: Despite similar ecological background characteristics, Malaysia was not as affected by the recent ZIKV outbreak compared to Brazil and Singapore. This could be related to pre-existing immunity against ZIKV in this population, which developed after the first introduction of the ZIKV in Malaysia decades ago. A serosurvey to determine the seroprevalence of ZIKV in Malaysia was carried out in 2017. The differences in circulating ZIKV strains could be another reason as to why Malaysia seemed to be protected from an outbreak.
RESULTS: In this study we generated Whole Exome Sequencing (WES), Reduced Representation Bisulfite Sequencing (RRBS) and RNA sequencing (RNA-seq) data from samples with known mixtures of mouse and human DNA or RNA and from a cohort of human breast cancers and their derived PDTXs. We show that using an In silico Combined human-mouse Reference Genome (ICRG) for alignment discriminates between human and mouse reads with up to 99.9% accuracy and decreases the number of false positive somatic mutations caused by misalignment by >99.9%. We also derived a model to estimate the human DNA content in independent PDTX samples. For RNA-seq and RRBS data analysis, the use of the ICRG allows dissecting computationally the transcriptome and methylome of human tumour cells and mouse stroma. In a direct comparison with previously reported approaches, our method showed similar or higher accuracy while requiring significantly less computing time.
CONCLUSIONS: The computational pipeline we describe here is a valuable tool for the molecular analysis of PDTXs as well as any other mixture of DNA or RNA species.
METHODS: Swab and fluid samples (n=358) from healthcare workers' hands, frequently touched surfaces, medical equipment, patients' immediate surroundings, ward sinks and toilets, and solutions or fluids of 12 selected wards were collected. Biochemical tests, PCR and 16S rRNA sequencing were used for identification following isolation from CHROMagar™ Orientation medium. Clinically important bacteria such as Enterococcus spp., Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter spp., Pseudomonas aeruginosa and Enterobacter spp. were further characterised by disc diffusion method and rep-PCR.
RESULTS: The 24 Gram-negative and 19 Gram-positive bacteria species identified were widely distributed in the hospital environment. Staphylococci were predominant, followed by Bacillus spp. and P. aeruginosa. Frequently touched surfaces, medical equipment, and ward sinks and toilets were the top three sources of bacterial species. Nine S. aureus, four Acinetobacter spp., one K. pneumoniae and one Enterobacter spp. were multidrug-resistant (MDR). The ESKAPE organisms were genetically diverse and widely dispersed across the hospital wards. A MDR MRSA clone was detected in a surgical ward isolation room.
CONCLUSION: The large variety of cultivable, clinically important bacteria, especially the genetically related MDR S. aureus, K. pneumoniae, Acinetobacter spp. and Enterobacter spp., from various sampling sites indicated that the surfaces and fomites in the hospital were potential exogenous sources of nosocomial infection in the hospital.