Ventilator-associated pneumonia (VAP) caused by drug-resistant Acinetobacter baumannii is associated with high mortality in critically ill patients. We identified the prognostic factors of 30-day mortality in patients with VAP caused by drug-resistant A. baumannii and compared survival outcomes among multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR) A. baumannii VAP. A retrospective cohort study was conducted in the Medical Intensive Care Unit at Chiang Mai University Hospital, Thailand. All adult patients diagnosed with A. baumannii VAP between 2005 and 2011 were eligible. Univariable and multivariable Cox’s proportional hazards regression were performed to identify the prognostic factors of 30-day mortality. A total of 337 patients with microbiologically confirmed A. baumannii VAP were included. The proportion of drug-sensitive (DS), MDR, XDR, and PDR A. baumannii were 9.8%, 21.4%, 65.3%, and 3.6%, respectively. The 30-day mortality rates were 21.2%, 31.9%, 56.8%, and 66.7%, respectively. The independent prognostic factors were SOFA score >5 (hazard ratio (HR) = 3.33, 95% confidence interval (CI) 1.94–5.72, P < 0.001), presence of septic shock (HR = 2.66, 95% CI 1.71–4.12, P < 0.001), Simplified Acute Physiology Score (SAPS) II >45 (HR = 1.58, 95% CI 1.01–2.46, P = 0.045), and inappropriate initial antibiotic treatment (HR = 1.53, 95% CI 1.08–2.20, P = 0.016). Drug-resistant A. baumannii, particularly XDR and PDR, was associated with a high mortality rate. Septic shock, high SAPS II, high SOFA score, and inappropriate initial antibiotic treatment were independent prognostic factors for 30-day mortality.

We conducted a retrospective cohort study in the medical intensive care unit of Chaing Mai University Hospital to describe the epidemiology of ventilator-associated pneumonia (YAP) and identify prognostic indicators of 30-day YAP mortality. A total of 621 patients diagnosed with YAP between January 2005 and December 2011 were included. The overall 30-day mortality rate was 44.4%. The major causative pathogens were Acinetobacter baumannii (54.3%), Pseudomonas aeruginosa (35.2%), and methicillin-resistant Staphylococcus aureus (15.1%). Most A. baumannii (90.2%) comprised drug-resistant strains. Identified prognostic indicators were co-morbid malignancy (hazard ratio [HR] = 1.60; 95% confidence interval [CI] 1.02-2.42; P = 0.040), septic shock (HR = 2.51; 95% CI, 1.60-4.00; P < 0.001), Simplified Acute Physiology Score II >45 (HR = 1.62; 95% CI, 1.03-2.56; P = 0.041), Sequential Organ Failure Assessment score >5 (HR = 3.40; 95% CI 2.00-5.81; P < 0.001), and delayed inappropriate empirical antibiotic treatment (HR = 2.23; 95% CI, 1.12-4.45; P = 0.022). YAP was associated with high mortality. The major causative pathogen was drug-resistant A. baumannii. Therefore, early detection of YAP by surveillance in mechanically ventilated patients leading to earlier treatment may improve patient outcomes. Guidelines for prescribing appropriate empirical antibiotics to cover drug-resistant bacteria could be established using local epidemiological data.

Open burnings, agricultural and forest fires, are the major sources of particulate matters (PM) in Chiang Mai during dry season. We aim to determine the association of an increased daily PM (PM₁₀, PM_2.5) and daily non-accidental mortality and causes of death in Chiang Mai. The association between PM and daily non-accidental mortality including causes of death were analyzed using a generalized linear model with Poisson distribution. The results showed that PM₁₀ and PM_2.5 were associated with daily non-accidental mortality on different lag days (adjusted RR range from 1.009–1.018 and 1.016 for each 10 µg/m³ increment of PM₁₀ and PM_2.5, respectively). The causes of death associated with PM₁₀, PM_2.5 found on different lag days were chronic obstructive pulmonary disease (COPD), coronary artery disease (CAD), and sepsis. We concluded that PM₁₀ and PM_2.5 are associated with daily non-accidental mortality and causes of death were COPD, CAD, and sepsis.

Various vaccines have been developed to control the COVID-19 pandemic, but the available vaccines were developed using ancestral SARS-CoV-2 wild-type (WT) strains. Commercial anti-SARS-CoV-2 receptor binding domain (RBD) antibody assays have been established and employed for validation of vaccine efficacy. However, these assays were developed before the SARS-CoV-2 variants of concern (VOCs) emerged. It is unclear whether anti-RBD IgG levels can predict immunity against VOCs. In this study, we determined the correlations between the levels of anti-RBD IgG and neutralizing antibodies (NAbs) against SARS-CoV-2 variants in vaccinated subjects. After vaccination, 100% of subjects showed an anti-RBD IgG response, whereas 82, 79, 30, 75, and 2% showed NAb responses against WT, Alpha, Beta, Delta, and Omicron variants, respectively. A high correlation was observed between anti-RBD IgG and NAbs against WT, Alpha, Beta, and Delta, but not so for the Omicron NAbs. Among subjects with high levels of anti-RBD IgG, 93, 93, 71, 93, and 0% of them had NAbs against WT, Alpha, Beta, Delta, and Omicron variants, respectively. These results indicate that anti-RBD IgG levels cannot be used as a predictor for the presence of NAbs against the globally dominant SARS-CoV-2 Omicron variant.