We compared the clinical characteristics and outcome of vaccinated hospitalized COVID-19 patients with unvaccinated hospitalized COVID-19 patients. A retrospective cohort study was conducted at the Sindh Infectious Diseases Hospital and Research Center, Karachi, Pakistan. A total of 1407 hospitalized COVID-19 positive patients were included from April 2021 to March 2022, of which 812 (57.71%) were males. Of the 1407, 378 (26.87%) patients were vaccinated while 1029 (73.13%) were unvaccinated. Of the vaccinated patients, 160 (42.32%) were partially vaccinated while 218 (57.68%) were fully vaccinated (vaccine breakthrough infection). Fewer unvaccinated COVID-19 patients survived compared to vaccinated patients (62.5% vs. 70%, RR 0.89, 95% CI: 0.82–0.96, p-value = 0.004). Despite there being more vaccinated patients above 60 years of age (60.05% vs. 47.13%), their risk of mortality was lower by 43% (OR = 0.578; CI = 0.4201 to 0.7980, p = 0.0009). On survival analysis, vaccinated patients had better 30-day survival compared to unvaccinated patients (p = 0.028). Moreover, comparing waves 3–5, unvaccinated patients of wave 4, which was driven by the delta variant, had the worst survival (51.8%, p ≤ 0.001) while vaccinated patients of wave 3 (driven by the alpha variant) had the best survival (71.6%).

Carbapenem-resistant Gram-negative (CR-GN) pathogens pose a critical threat to patient outcomes in high-dependency and intensive care environments. This study aimed to delineate species prevalence, antimicrobial resistance phenotypes, carbapenemase genotypes, and clinical–environmental transmission dynamics across critical-care units. Cross-sectional surveillance was conducted in six ICUs and HDUs of a tertiary-care hospital in Karachi, Pakistan. We identified predominant species, quantified resistance patterns, and detected carbapenemase genes using PCR, exclusively on meropenem-resistant isolates. Network analysis highlighted high-centrality contamination hubs across ICUs and HDUs. Acinetobacter baumannii (36.7%) and Klebsiella pneumoniae (33.9%) were predominant, with 58% originating from environmental reservoirs. Meropenem non-susceptibility was 55% (60/109), and colistin non-susceptibility was 68.6% (35/51), based on standardized CLSI testing. ICU isolates exhibited significantly higher meropenem resistance than HDU isolates. Among carbapenem-resistant isolates, blaOXA-48-like (52.8%) and blaNDM (25%) were most prevalent. Network topology revealed ICU1 and HDU2 as high-centrality transmission nodes. These findings highlight pervasive environmental colonization and heightened antimicrobial pressure in ICUs, necessitating reinforced decontamination protocols, antimicrobial stewardship, and continuous molecular surveillance. This study provides the first integrated clinical–environmental surveillance of MDR Gram-negative bacteria in Pakistan, revealing that over half of isolates originated from surfaces and that network-based mapping can pinpoint contamination hubs driving hospital transmission.

Background: Each coronavirus disease 2019 (COVID-19) wave is unique in its clinical presentation and outcome. In this study, we compared the clinical characteristics and outcomes of COVID waves 2–5 in inpatient settings. Methods: A retrospective study was conducted at the Sindh Infectious Diseases Hospital and Research Center on adult patients who were admitted with a positive COVID polymerase chain reaction from July 2020 to March 2022. SPSS 26 was used to analyze the data. Results: A total of 3190 COVID-19 patients were admitted. Wave 2 had the highest percentage of discharges compared with mortality (81%; P = .0001). Cytokine release syndrome was most common in wave 3 (32.7%; P = .0001). Severe COVID on admission was predominant in wave 4 (79.4%; P = .0001), with the highest rates of intubation (27.1%; P = .0001), septic shock (24.3%; P = .0001), and disease progression (50.8%; P = .0001). In wave 5, the majority were elderly (median age, 68 years) and had mild COVID (22.4%; P = .0001), most had comorbidities (84.6%; P = .0001), and the ratio of acute kidney injury was high (29.2%; P = .0001). Mortality was lowest in wave 2 (18.9%; P = .0001) and highest in wave 4 (42.5%; P = .0001; odds ratio, 3.18; 95% CI, 2.6–3.8; compared with wave 2). Conclusions: Each wave had some unique characteristics compared with other waves, with wave 4, driven by the Delta variant, being the deadliest one in terms of disease severity and outcomes.

Background: The COVID-19 pandemic caused significant loss to healthcare systems across the world. Patients usually presented with fever and cough as the primary symptoms. This paper aims to discuss the clinical features, outcomes, areas of work, and duration of absence from work in employees working at a tertiary care renal hospital in Pakistan. Material and Methods: Data of employees who were suspected of having COVID-19 was compiled and divided into waves according to the COVID-19 waves in Pakistan. The clinical characteristics and duration till return to work was calculated and compared among waves using Chi-square test. Results: Five waves of COVID-19 were observed during the study. A total of 620 employees were tested during the waves, of which 216 (35%) tested positive. Of those who tested positive, most were healthcare workers (n=165 [76%], p-value <0.01). The most common symptom among positive cases was fever and least common was a combination of fever cough (p-value <0.01). The duration of absence from work dropped from a maximum of 43 days in the first wave to five days in the fifth wave. A total of 4763 employee days were lost during the pandemic. Conclusion: Strict implication of safety protocols in the workplace followed by astute management strategies must be maintained. Now that the pandemic is nearly over, strategies to mitigate outbreaks in the hospital should be limited to screening employees with fever and cough to preserve resources and reduce employees’ absence from work. Keywords: COVID-19, Healthcare workers, Absence of employees, Fever and cough, Duration of absence

Background: Raoultella terrigena (formerly Klebsiella terrigena) is an environmental gram-negative rod. It can cause infections in humans, especially in immunosuppressed patients and tends to be multi-drug resistant, limiting treatment options. There is lack of data on clinical presentation and outcomes of infections due to this organism. In this study; we describe the clinical features (presenting complaints, co-morbid diseases, complications, etc.), available treatment options, and outcomes (hospital/ICU stay, mortality) of patients with R. terrigena infections, seen retrospectively over six years. Material and Methods: A cross-sectional study was conducted on all adult hospitalized patients with clinical specimens positive for Raoultella terrigena at a 700-bedded tertiary care hospital in Karachi, Pakistan, from January 2013 to December 2018. Results: We identified 58 patients with R. terrigena isolated from different cultures specimens, of which n=12 (22.6%) were colonizers. The median age was 61.5 years (IQR=43-71), and most were male (n=28). The most common site of infection was the respiratory tract in 28.3%, then urinary tract in 26%, and central line in 26.1%. Amongst infected cases, 37% had septic shock, 45.7% had respiratory failure. Conclusion: R. terrigena is a multi-drug-resistant organism with a high mortality rate and can cause hospital-acquired respiratory tract infections in patients. Keywords: Raoultella terrigena, Klebsiella terrigena, Raoultella species, Klebsiella species.