Assessing required SARS-CoV-2 blanket testing rates for possible control of the outbreak in the epicentre Lusaka province of Zambia with consideration for asymptomatic individuals: A simple mathematical modelling study

Introduction The novel Coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus—2 (SARS-CoV-2), in Africa is characterised by a more substantial proportion of asymptomatic (or mildly symptomatic) individuals thought to be playing a role in the spread of the infection. The exact proportion and degree of infectiousness of asymptomatic individuals remains unclear. Studies however indicate that their management is crucial for control of SARS-CoV-2 transmission. Methodology We developed a simplified deterministic susceptible-exposed-infectious-removed (SEIR) mathematical model to assess the effect of active isolation of SARS-CoV-2 infected but asymptomatic individuals through blanket testing for control of the outbreak in Lusaka Province of Zambia. Here we modelled two scenarios; (1) assuming asymptomatic individuals comprised 70% of all COVID-19 cases and (2) asymptomatic individuals comprised only 50% of the cases. For contrast, the model was assessed first under the assumption that asymptomatic individuals are equally as infectious as symptomatic individuals and then secondly, and more likely, assuming asymptomatic individuals are only half as infectious as symptomatic individuals. Results For the model assuming 70% asymptomatic cases, a minimum sustained daily blanket testing rate of ≥ 7911 tests/100000 population was sufficient to control the outbreak if asymptomatic individuals are only half as infectious while if equal infectiousness was assumed then a testing rate of ≥ 10028 tests/ 100000 population would be required. For 50% asymptomatic, minimum blanket testing rates of ≥ 4540 tests/ 100000 population was sufficient to control the outbreak at both assumed levels of infectiousness for asymptomatic individuals relative to symptomatic individuals. Discussion and conclusion Our model predicts that active isolation of COVID-19 cases, including asymptomatic individuals, through blanket testing can be used as a possible measure for the control of the SARS-Cov-2 transmission in Lusaka, Zambia, but it would come at a high cost.

Assessing the effects of exposure to a SARS-CoV-2 re-positive patient in healthcare personnel

Objective To evaluate whether patients with COVID-19 who have tested re-positive with the PCR test for the SARS-CoV-2 virus are infectious is a challenge in the current circumstances. A follow-up survey was conducted with healthcare personnel (HCP) who were exposed to a patient whose PCR test results for SARS-CoV-2 were re-positive 18 days after the initial confirmation of negative PCR results. Results We studied a total of 15 HCP who had contact exposures (15/15) and aerosol exposures (7/15). None of them tested positive for IgG against SARS-CoV-2 on blood examination. None of them had any symptoms during 10 days of active isolation. All PCR tests conducted using the nasopharyngeal swabs collected from the HCP on day 10 were negative. No apparent infection was found in any of the HCP who had contact exposure with and/or aerosol exposure to the patient whose PCR test results for SARS-CoV-2 were re-positive 18 days after the initial confirmation of negative results of PCR tests for SARS-CoV-2. Clinical trial: Trial Registration: No. 170, approved June 10th, 2020 by the ethics committee of Sakai City Medical Center.

Neonatal septicemia caused by a rare pathogen: Raoultella planticola - a report of four cases

Background Raoultella planticola(R.planticola) is a very rare opportunistic pathogen and sometimes even associated with fatal infection in pediatric cases. Recently,the emergence of carbapenem resistance strains are constantly being reported and a growing source of concern for pediatricians. Case presentation We reported 4 cases of neonatal septicemia caused by Raoultella planticola. Their gestational age was 211 to 269 days, and their birth weight was 1490 to 3000 g.The R. planticola infections were detected on the 9th to 27th day after hospitalization and occured between May and June. They clinically manifested as poor mental response, recurrent cyanosis, apnea, decreased heart rate and blood oxygen, recurrent jaundice, fever or nonelevation of body temperature. The C-reactive protein and procalcitonin were elevated at significantly in the initial phase of the infection,and they had leukocytosis or leukopenia. Prior to R.planticola infection,all of them recevied at least one broad-spectrum antibiotic for 7-27d.All the R.planticola strains detected were only sensitive to amikacin, but resistant to other groups of drugs: cephalosporins (such as cefazolin, ceftetan,etc) and penicillins (such as ampicillin-sulbactam,piperacillin,etc),and even developed resistance to carbapenem. All the infants were clinically cured and discharged with overall good prognosis. Conclusion Neonatal septicemia caused by Raoultella planticola mostly occured in hot and humid summer, which lack specific clinical manifestations. Pediatricians should keep in mind that R. planticola can be a potential source of neonatal sepsis and even has the potential to acquire carbapenem-resistance. Preventing outbreaks of epidemics requires early detection, timely diagnosis and treatment, and active isolation.

Assessing the effects of exposure to a SARS-CoV-2 re-positive patient in healthcare personnel

Objective: To evaluate whether patients with COVID-19 who have tested re-positive with the PCR test for the SARS-CoV-2 virus are infectious is a challenge in the current circumstances. A follow-up survey was conducted with healthcare personnel (HCP) who were exposed to a patient whose PCR test results for SARS-CoV-2 were re-positive 18 days after the initial confirmation of negative PCR results.Results: We studied a total of 15 HCP who had contact exposures (15/15) and aerosol exposures (7/15). None of them tested positive for IgG against SARS-CoV-2 on blood examination. None of them had any symptoms during 10 days of active isolation. All PCR tests conducted using the nasopharyngeal swabs collected from the HCP on day 10 were negative. No apparent infection was found in any of the HCP who had contact exposure with and/or aerosol exposure from the patient whose PCR test results for SARS-CoV-2 were re-positive 18 days after the initial confirmation of negative results of PCR tests for SARS-CoV-2.Trial Registration: No. 170, approved June 10th, 2020 by the ethics committee of Sakai City Medical Center.

How to keep patients and staff safe from accidental SARS-CoV-2 exposure in the emergency room: Lessons from South Korea’s explosive COVID-19 outbreak

Objectives:We report our experience with an emergency room (ER) shutdown related to an accidental exposure to a patient with coronavirus disease 2019 (COVID-19) who had not been isolated.Setting:A 635-bed, tertiary-care hospital in Daegu, South Korea.Methods:To prevent nosocomial transmission of the disease, we subsequently isolated patients with suspected symptoms, relevant radiographic findings, or epidemiology. Severe acute respiratory coronavirus 2 (SARS-CoV-2) reverse-transcriptase polymerase chain reaction assays (RT-PCR) were performed for most patients requiring hospitalization. A universal mask policy and comprehensive use of personal protective equipment (PPE) were implemented. We analyzed effects of these interventions.Results:From the pre-shutdown period (February 10–25, 2020) to the post-shutdown period (February 28 to March 16, 2020), the mean hourly turnaround time decreased from 23:31 ±6:43 hours to 9:27 ±3:41 hours (P < .001). As a result, the proportion of the patients tested increased from 5.8% (N=1,037) to 64.6% (N=690) (P < .001) and the average number of tests per day increased from 3.8±4.3 to 24.7±5.0 (P < .001). All 23 patients with COVID-19 in the post-shutdown period were isolated in the ER without any problematic accidental exposure or nosocomial transmission. After the shutdown, several metrics increased. The median duration of stay in the ER among hospitalized patients increased from 4:30 hours (interquartile range [IQR], 2:17–9:48) to 14:33 hours (IQR, 6:55–24:50) (P < .001). Rates of intensive care unit admissions increased from 1.4% to 2.9% (P = .023), and mortality increased from 0.9% to 3.0% (P = .001).Conclusions:Problematic accidental exposure and nosocomial transmission of COVID-19 can be successfully prevented through active isolation and surveillance policies and comprehensive PPE use despite longer ER stays and the presence of more severely ill patients during a severe COVID-19 outbreak.

Assessing required SARS-CoV-2 blanket testing rates for possible control of the outbreak in the epicentre Lusaka province of Zambia with consideration for asymptomatic individuals: a simple mathematical modelling study.

Introduction: The novel Coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus - 2 (SARS-CoV-2), in Africa is characterised by a more substantial proportion of asymptomatic (or mildly symptomatic) individuals thought to be playing a role in the spread of the infection. The exact proportion and degree of infectiousness of asymptomatic individuals remains unclear. Studies however indicate that their management is crucial for control of SARS-CoV-2 transmission. Methodology: We developed a simplified deterministic susceptible-exposed-infectious-removed (SEIR) mathematical model to assess the effect of active isolation of SARS-CoV-2 infected but asymptomatic individuals through blanket testing for control of the outbreak in Lusaka Province of Zambia. Here we modelled two scenarios; (1) assuming asymptomatic individuals comprised 70% of all COVID-19 cases and (2) asymptomatic individuals comprised only 50% of the cases. For contrast, the model was assessed first under the assumption that asymptomatic individuals are equally as infectious as symptomatic individuals and then secondly, and more likely, assuming asymptomatic individuals are only half as infectious as symptomatic individuals. Results: For the model assuming 70% asymptomatic cases, a minimum sustained blanket testing rate of ≥ 7911 tests/100000 population was sufficient to control the outbreak if asymptomatic individuals are only half as infectious while if equal infectiousness was assumed then a testing rate of ≥ 10028 tests/ 100000 population would be required. For 50% asymptomatic, minimum blanket testing rates of ≥ 4540 tests/ 100000 population was sufficient to control the outbreak at both assumed levels of infectiousness for asymptomatic individuals relative to symptomatic individuals. Discussion and conclusion: Our model predicts that the current testing rates of ≈ 150/100,000 population are inadequate to control transmission of SARS-Cov-2 in Lusaka. Active isolation of COVID-19 cases including asymptomatic individuals through blanket testing can be used as a possible measure for control of the SARS-Cov-2 transmission in Lusaka, Zambia. Key words: SARS-Cov-2, asymptomatic transmission, deterministic model, blanket testing