Comparison of Clinical Characteristics and Outcome of COVID-19 Patients Between the 4th and 5th Wave in a Tertiary Care Hospital in Karachi, Pakistan.

ABSTRACT       Objective: To compare the clinical parameters of 4th and 5th COVID waves in Karachi, Pakistan. STUDY DESIGN: Descriptive study. Place and Duration of the Study: PNS Shifa Hospital, Karachi, from July 2021 to February 2022. METHODOLOGY: All patients with COVID-19 in PNS Shifa Hospital were included in the study. The patients were divided into two groups, those who had COVID-19 during the 4th wave, and others who had it during the 5th wave. The patients' demographic details, comorbidities, vaccination status, initial presentation, the severity of disease, clinical progress, and final disposal from the hospital were noted. A comparison of severity, length of hospital stays, and mortality was made between the groups. RESULTS: There were 747 patients admitted during the Delta variant-dominated 4th wave of COVID-19, and 490 patients during the 5th wave, dominated by the Omicron variant. A vast majority of fifth-wave patients had the mild disease (87.35% vs. 49.39%), with significantly lower critical patients (2.04% vs. 7.09%). Vaccination was effective against both the Delta and the Omicron variant of the SARS-CoV-2 virus. The mean length of stay in the hospital for patients was significantly lesser (p < 0.001) during the 5th wave as compared to the 4th wave (6.43 ± 3.37 vs. 9.56 ± 5.45 days). The mortality rate was 7.09% among patients admitted in the 4th wave and 2.04% in the 5th wave. This difference was statistically significant (p < 0.001). CONCLUSION: The severity of disease, length of hospital stays, and mortality were higher in the Delta variant-dominated 4th wave of COVID-19 as compared to the Omicron variant-dominated 5th wave in Pakistan. The vaccination was effective against both the Delta and the Omicron variant of COVID 19, as the mortality rate among the vaccinated patients during the two waves was not significantly different. KEY WORDS: COVID 19, Vaccination, Disease outcome, Mortality.

Rapid detection of ceftriaxone resistance in clinical isolates of extensively drug resistant Salmonella enterica serovar Typhi.

OBJECTIVE: To see the efficacy of rapid colour test for the sensitivity of ceftriaxone against clinical isolates of salmonella typhi. METHODS: The cross-sectional validation study was conducted at the Department of Microbiology, Pakistan Navy Ship Shifa Hospital, Karachi, from Nov 2018 to April 2019, and comprised clinical isolates of salmonella typhi that were obtained from five different hospitals in Karachi and Hyderabad. The isolates were tested using the rapid colour test. All the isolates were also tested using the conventional disc diffusion method and minimum inhibitory concentrations on the Vitek-2 version 8.01. RESULTS: Of the 97 isolates, 83(85.5%) were ceftriaxone-resistant and 14(14.4%) were ceftriaxone-sensitive. Sensitivity and specificity of the rapid colour test were 100% when compared with the results of the other methods. All the results were readable within 2 hours on the colour test. CONCLUSIONS: The colour test was found to be a rapid, accurate and inexpensive tool to screen for ceftriaxone resistance in typhoid-endemic areas.

Evaluation of Nitrate Reductase Assay for Early Detection of Multi and Extensively Drug Resistance Tuberculosis in our Setup.

OBJECTIVE: To evaluate the performance of nitrate reductase assay on smear positive pulmonary specimens for detection of multi and extensively drug resistant tuberculosis simultaneously. STUDY DESIGN: Cross-sectional analytical study. PLACE AND DURATION OF STUDY: Microbiology Department, Armed Forces Institute of Pathology, Rawalpindi from June to December 2016. METHODOLOGY: Smear positive pulmonary samples were processed both by nitrate reductase method on Lowenstein Jenson medium and also inoculated on gold standard Bactec MGIT 960 TB system. All the specimens were first digested and decontaminated according to standard protocol before inoculation. RESULTS: Out of total 76 samples, three did not give color and, therefore, were excluded from the final data analysis. Among the remaining 73 samples, mycobacterial index was: 28 specimens were having 1+ (1-9 bacilli/100 fields), 26 samples were 2+ (1-9 bacilli/ field), and 19 samples were having 3+ index (>9 bacilli/field). The respective sensitivity and specificity were 84% and 100% for isoniazid (INH); 82% and 100% for rifampin (RIF); 67% and 100% for amikacin (AK); and both 100% for ofloxacin (OFX). Overall agreement in case of INH, RIF, AK, and OFX was 94.5%, 97.2%, 98.6% and100%, respectively. Overall average agreement was 97.5%. CONCLUSION: Nitrate reductase assay is a reliable, low cost and accurate method that can be used for early for diagnosis of multi and extensively drug resistant tuberculosis.