"Day 25": a temporal indicator of stabilization of mortality risk among COVID-19 patients with high viral load.

INTRODUCTION: The relationship between SARS-CoV-2 viral load and hospitalization and mortality among COVID-19 patients has been established. However, the estimation of the duration of time after which the risk of mortality of these patients stops escalating was not extensively discussed earlier. Stratifying patients according to their risk of mortality would optimize healthcare services and costs and reduce mortality. METHODOLOGY: In this retrospective observational study, hospital records were used to collect data of 519 COVID-19 patients from May through November 2020. Data included the clinical condition of patients, their viral loads, their admission chest computed tomography results (CO-RAD scale), and the duration of their hospitalization. A Kaplan-Meier analysis was constructed to estimate mortality risk concerning viral load. RESULTS: By the end of the study, 20.42% of patients were deceased. The cumulative mortality was: 36.1% (75/208) among patients with high viral load, 12.6% (28/222) in those with moderate viral load, and 3.4% (3/89) among those with low viral load. Predictors of mortality were: older age [adjusted hazard ratio (aHR) = 1.02, 95% CI: [1.00-1.03], (p = 0.05)], "being female" [aHR = 1.53 with 95% CI: [1.03-2.26], (p = 0.031), "high CO-RAD scale" [aHR = 1.32 (1.06-1.64), p = 0.013], "high viral load" [aHR = 4.59 (2.38-20.92), p = 0.017, ICU admission [aHR = 15.95; 95%CI:7.22-35.20, p < 0.001] and lymphocytosis [aHR = 1.89 45;95%CI:1.04-3.45, p = 0.036]. In the ICU-admitted patients, the median survival was 19 days and mortality stabilized at "day 25". For patients with high viral load, mortality rates stabilized at "day 25 post-admission" after which the risks of mortality did not change until day 40, while patients with low and moderate viral loads reached the peak and stabilized at day "20 post-admission". CONCLUSIONS: Initial high SARS-CoV-2 viral load might be used as an indicator of a delayed stabilization of mortality risk among COVID-19 patients.

Role of environmental surfaces and hands of healthcare workers in perpetuating multi-drug-resistant pathogens in a neonatal intensive care unit.

Neonates admitted to neonatal intensive care units are at a risk of developing healthcare-associated infections, leading to increased risk of mortality. This study aimed to identify organisms causing such late-onset infections in neonates and determine whether these isolates were genetically identical to those from the surrounding environmental surfaces and hands of healthcare workers (HCWs). A cross-sectional study was carried out over a period of 4 months in a university neonatal intensive care unit (NICU). Samples were collected from all neonates with symptoms of late-onset infections (n = 180). Fingerprint samples of 21 healthcare workers as well as 330 random environmental samples were also taken from the unit. Isolates from neonates, environment and fingerprints were subjected to protein electrophoresis followed by sequencing to detect genetic similarities. Almost half of neonatal samples were culture positive (91/180, 50.6%), out of which 72% of bacterial isolates (49/68) were multi-drug resistant. Klebsiella pneumoniae (32.6%) and Candida spp. (28.4%) were the commonest neonatal isolates. A cluster of two homologous Klebsiella pneumoniae strains was isolated from a neonate and an examining bed, while another homologous cluster was from a neonatal sample and a portal incubator. A third cluster was isolated from hands and three neonatal samples. This cluster (caused by Klebsiella pneumoniae strain NH54 chromosome) was found to perpetuate over the 4 months of the study. All three clusters were multi-drug-resistant Klebsiella pneumoniae. A homologous pair of each of Candida tropicalis and Candida glabrata was isolated from the blood of two neonates, and one neonatal and a crash cart sample, respectively. Overall, 8.8% (8/91) of neonatal samples were found to be homologous to other neonatal/environmental/hand isolates, denoting perpetuation of pathogens between neonates themselves and also other reservoirs of infections.Conclusion: The hands of HCWs, crash carts and incubators are reservoirs of pathogens and can lead to nosocomial infections. Clusters of multi-drug-resistant Klebsiella pneumoniae and Candida spp. were the predominant neonatal pathogens in this NICU. What is Known: • The role of hands and the environment in transmission of infections to neonates is a subject of debate. • Genetic sequencing provides solid evidence for detecting homologous strains. What is New: • K. pneumoniae was the most frequently isolated pathogen, and concomitant isolation was found in two cases from the neonatal surroundings (bed/incubator) and hands. • Candida spp. with homology were also found in different neonates and environmental samples suggesting risk of transmission.

Microbial Contamination of Neonatal Injectable Lipid Emulsions at 12 and 24 Hours' Infusion Time With Evaluation of Infection Control Measures.

OBJECTIVES: This study aimed to assess the microbial contamination rate of injectable lipid emulsion (ILE) repackaged syringes at 12 and 24 hours of their infusion time. Probable risk factors associated with contamination of the ILEs were also assessed. In addition, the antimicrobial resistance pattern of the bacterial isolates was also determined. METHODS: Samples of ILE were collected from 152 repackaged syringes and their infusion lines after 12 hours and 24 hours of infusion time (73 and 79 samples, respectively). Samples were cultured, the isolates were identified, and the antimicrobial resistance pattern of the bacterial isolates was identified. A checklist was completed throughout the study to observe the compliance to infection control measures by pharmacists (who prepare) and nurses (who administer) the ILE infusions. Results of septic neonatal cultures were taken from records. RESULTS: Microbial contamination was found in 15.8% of ILE samples. The 2 most common pathogens found among positive samples were Klebsiella pneumoniae (29.2%) and Candida albicans (20.8%). Microbial contamination of repackaged syringes increased from 9.6% at 12 hours to 21.5% at 24 hours. This difference was found to be statistically significant (p = 0.044). A similar trend of predominance of those 2 pathogens, in both ILE and neonatal cultures, was observed. There was a statistically significant better performance of infection control measures of pharmacists rather than nurses. The K pneumoniae isolates (n = 7) showed antibiotic resistance in the following pattern: gentamicin (71.4%), cefazolin (85.7%), and cefoxitin (85.7%). CONCLUSIONS: The rate of ILE contamination was less at 12 hours' than at 24 hours' infusion time. However, contamination rates at 12 hours were unacceptably high. Klebisella pneumoniae and C albicans were the most common pathogens isolated from ILE. Compliance with infection control measures was significantly worse among nurses compared with pharmacists.

Evaluation of antibiotic susceptibility test results: how guilty a laboratory could be?

BACKGROUND: The selection of an appropriate antimicrobial is a challenging task for clinicians. The Kirby-Bauer disk diffusion method is one of the most widely practiced antimicrobial susceptibility tests (AST). It is affected by many factors among which are the media used. Mueller-Hinton agar (MHA) is the standard medium recommended in guidelines. However, these guidelines are not strictly adhered to in some developing countries. OBJECTIVES: Validation of AST results on nutrient agar (NA) medium used as a substitute for MHA by some microbiology laboratories in Alexandria, Egypt. METHODS: A total of 149 clinical bacterial isolates and 3 reference strains: Staphylococcus aureus (S. aureus) ATCC® 25923, Escherichia coli (E. coli) ATCC®25922, and Pseudomonas aeruginosa (P. aeruginosa) ATCC®27853 were comparatively challenged to antibiotics employing MHA and NA. RESULTS: All antibiotics-reference bacterial strain challenges on NA compared to MHA were unacceptable (> 3 out of limit zones in 30 consecutive days). Considering clinical isolates, the frequency of very major, major, and minor errors on NA was highest in the case of P. aeruginosa (8.98%, 4.08%, and 14.7% respectively) followed by S. aureus (7.6%, 6%, and 8.8% respectively). On the other hand, the least frequency of errors was in the case of Enterobacteriaceae (0%, 0.4%, and 3.2% respectively). CONCLUSIONS AND RECOMMENDATIONS: Using NA in AST resulted in multiple errors and the high discrepancy in results compared to MHA making it unreliable for susceptibility testing. MHA should not be replaced by NA in AST. Following guidelines and QC measures for AST must be neither bypassed nor underestimated.

Diagnosis of pulmonary tuberculosis using Ziehl-Neelsen stain or cold staining techniques?

BACKGROUND: Acid-fast bacilli microscopy is the first step in the diagnosis and screening of pulmonary tuberculosis (PTB) in developing countries. It remains a rapid and inexpensive diagnostic tool for diagnosing a large number of PTB cases with limited resources. OBJECTIVE: To evaluate three different staining techniques used in the detection of acid-fast bacilli. The conventional Ziehl-Neelsen (ZN) stain and two cold stains, Gabbett's cold stain and modified cold stain (MCS), were compared with sputum culture. MATERIALS AND METHODS: A total of 300 sputum samples from 100 clinically suspected PTB patients referred to Maamorah Chest Hospital in Alexandria, Egypt, were tested. For staining and culture, three sputum samples from each patient were collected (one 'on spot' and two early morning samples) and pooled together. Smears were prepared using three different staining methods (ZN, Gabbett's cold stain, and MCS) and were inoculated in the Lowenstein-Jensen media. RESULTS: Comparison of sputum staining results using three different staining techniques versus culture proved that the highest sensitivity and specificity were seen for Gabbett's stain (76.6 and 98.5%, respectively). ZN stain had a sensitivity and specificity of 70 and 97.1%, whereas MCS had a sensitivity and specificity of 60 and 95.7%, respectively. CONCLUSION: Gabbett's stain was more accurate in the diagnosis of PTB compared with both ZN and MCS, even though the results were not statistically significant. It can replace ZN for initial diagnosis and follow up of cases. It is also easier, faster, and does not require a heating step.

Is it safe to eat raw seafood? Prevalence of Salmonella in some seafood products sold in Alexandria markets.

BACKGROUND: Salmonella is a significant microbial hazard in seafood. Salmonella-contaminated seafood usually looks and smells normal; it is therefore essential that every effort is made toward the rapid detection of Salmonella as an important criterion in quality control of seafood. AIMS: This study aims to determine the percentage of Salmonella in some Egyptian seafood sold in Alexandria markets and to study the validity of Chromagar Salmonella Plus (CASP) agar versus xylose lysine desoxycholate and Salmonella-Shigella agar for the isolation and identification of Salmonella in seafood. MATERIALS AND METHODS: Two hundred and twenty-five samples of three seafood types, shrimp, gandofli, and river mussel (om-elkhloul) were studied. Samples were selectively enriched in Rappaport-Vassiliadis and tetrathionate broth, and then plated onto the aforementioned plating media for the detection of Salmonella. RESULTS: In total, Salmonella was detected in 9.8% of the samples. The sensitivity and specificity of the media used varied according to the media and enrichment broth combinations used. The CASP and Rappaport-Vassiliadis combination yielded the best sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 95.45, 100, 100, 99.5, and 99.5%, respectively. CONCLUSION AND RECOMMENDATION: CASP was more accurate than xylose lysine desoxycholate and Salmonella-Shigella in the detection of Salmonella from seafood samples. We recommend that CASP medium should be tested against more Salmonella-positive samples before it is used as a screening plating medium for Salmonella in seafood.

The dilemma of widal test - which brand to use? a study of four different widal brands: a cross sectional comparative study.

BACKGROUND: Serodiagnosis of typhoid fever by Widal test based on demonstrating the presence of agglutinins (antibodies) in the serum of an infected patient, against the H (flagellar) and O (somatic) antigens of Salmonella enterica serotype Typhi has been associated with many debates. This is why the aim of this study was to: (i) Compare the diagnostic accuracy of four different commercial kits used to perform Widal test (Remel, BioSystems, Dialab and Biotec). (ii) Compare the sensitivity and specificity of both anti-O and anti-H antibodies. (iii) Compare the validity of single versus paired serum samples with a rising titer for the diagnosis of typhoid fever. METHODS: Duplicate serum samples were obtained from 150 patients clinically diagnosed as typhoid fever patients. Moreover, single serum samples were obtained from 25 patients with febrile diseases other than typhoid fever. All samples were tested using the four different Widal brands and Salmonella Typhi IgM anti-LPS ELISA. RESULTS: -The results of Widal tests differed markedly using the four Widal brands in terms of sensitivity and specificity at three cut-off values of 1/80, 1/160 and 1/320. Remel brand gave the highest sensitivities and the lowest specificities and Dialab brand gave the highest specificities and the lowest sensitivities for both anti-O and anti-H antibodies at the three cut-off values.-Four fold rise in the antibodies titer was not demonstrable among clinically diagnosed typhoid fever patients-H agglutinins were less sensitive and less specific than O agglutinins CONCLUSIONS: -Widal test results showed marked discrepancies using different Widal brands. None of the serum samples of the typhoid fever patients showed four fold rise in the antibody titers. Raised O agglutinins were of slightly greater diagnostic value than raised H agglutinins. SIGNIFICANCE AND IMPACT OF STUDY: Widal test done sequentially using two brands could be of value in typhoid fever diagnosis. Single serum sample could be used for typhoid fever diagnosis relying on anti O titer.

Detection of coagulase positive staphylococci in meat products sold in Alexandria using two different media.

Microbiological examination of 200 meat products collected from 30 supermarkets in Alexandria revealed that CHROMagar Staph aureus yielded higher counts than Baird Parker medium that were significant in all examined products except sausage. The prevalence of coagulase positive staphylococci was 4%, moreover, CHROMagar Staph aureus showed higher recovery rate and specificity (87.5% and 98.9%; respectively) than Baird Parker medium (50.0% and 15.6%; respectively) during their detection. Sanitary evaluation of the supermarkets revealed that all of them were acceptable regarding prevention of bacterial growth parameter, although their mean score was only 55%. Avoidance of contamination parameter had the lowest mean score percent (15.6 +/- 27.3) with only about seven percent of the inspected supermarkets being acceptable. Although all recruited food handlers were apparently healthy, in few supermarkets, handlers were wearing clean light colored uniform (6.7%) and gloves (3.3%). Despite the presence of hand washing basins in all supermarkets, few of them were provided with hot water (6.7%) and detergents were available in 30% of them. Improvement of the sanitary conditions under which meat products are handled in the supermarkets is a must, also, improving the selectivity of CHROMagar Staph aureus in addition to both specificity and recovery rates of Baird Parker medium is recommended.