Serologic Evaluation of MERS Screening Strategy for Healthcare Personnel During a Hospital-Associated Outbreak

Estimating the Neutralizing Effect and Titer Correlation of Semi-Quantitative Anti-SARS-CoV-2 Antibody Immunoassays

For the clinical application of semi-quantitative anti-SARS-CoV-2 antibody tests, the analytical performance and titer correlation of the plaque reduction neutralization test (PRNT) need to be investigated. We evaluated the analytical performance and PRNT titer-correlation of one surrogate virus neutralization test (sVNT) kit and three chemiluminescent assays. We measured the total antibodies for the receptor-binding domain (RBD) of the spike protein, total antibodies for the nucleocapsid protein (NP), and IgG antibodies for the RBD. All three chemiluminescent assays showed high analytical performance for the detection of SARS-CoV-2 infection, with a sensitivity ≥ 98% and specificity ≥ 99%; those of the sVNT were slightly lower. The representativeness of the neutralizing activity of PRNT ND₅₀ ≥ 20 was comparable among the four immunoassays (Cohen’s kappa ≈ 0.80). Quantitative titer correlation for high PRNT titers of ND₅₀ ≥ 50, 200, and 1,000 was investigated with new cut-off values; the anti-RBD IgG antibody kit showed the best performance. It also showed the best linear correlation with PRNT titer in both the acute and convalescent phases (Pearson’s R 0.81 and 0.72, respectively). Due to the slowly waning titer of anti-NP antibodies, the correlation with PRNT titer at the convalescent phase was poor. In conclusion, semi-quantitative immunoassay kits targeting the RBD showed neutralizing activity that was correlated by titer; measurement of anti-NP antibodies would be useful for determining past infections.

Evaluation of six anti-SARS-CoV-2 antibody test kits and practical approaches to optimize the diagnostic performance

In an investigation of six anti-SARS-CoV-2 antibody kits with different target antigen and methodology, each kit showed comparable performance. As false-positive reactions occurred independently with different kits, specificity increased to 100% when pairs of kits were used. With three-kit combination, both sensitivity (99.1%) and specificity (100%) increased.

[Strategy for planning and execution of a large-scale SARS-CoV-2 seroprevalence study on teaching hospital workers during a pandemic situation]

Objetivo

Describir el proceso de planificación y ejecución de un estudio masivo de seroprevalencia para SARS-CoV-2 en los profesionales del Hospital Universitario Fundación Alcorcón (HUFA) (España).

Método

Se efectúa una descripción del plan diseñado y desarrollado en el HUFA para la realización de las extracciones de las muestras para serología en el total de los profesionales que prestan servicio en el hospital, entre el 14 y el 29 de abril del 2020. Se lleva a cabo un análisis descriptivo de la participación de los profesionales en el estudio. De igual manera, se planificaron zonas de extracción, personal sanitario y tiempos de ejecución. Se asignaron 2.326 extracciones a personal sanitario, el resto fueron a trabajadores de las empresas externas.

Resultados

Participaron en el estudio 2.641 trabajadores (90,5%) de 2.918 candidatos. La categoría profesional que más se analizó globalmente fue la de enfermería con un 28,3% (n = 590). El porcentaje de cumplimiento de la organización de los horarios fue del 28,6%. Se planificó hasta un máximo de 298 extracciones diarias. El día con más afluencia fue el cuarto con 399 extracciones.

Conclusiones

El hecho de organizar un dispositivo tan grande con un alcance al 100% de los trabajadores que prestan servicio en el hospital, y con una respuesta tan mayoritaria por parte de ellos, ha permitido que el estudio de seroprevalencia realizado obtenga unos resultados con alta fiabilidad. Aunque el porcentaje de participación fue muy alto, el grado de cumplimiento de la planificación fue reducido.

Serologic Evaluation of Healthcare Workers Caring for COVID-19 Patients in the Republic of Korea

The safety of healthcare workers (HCWs) against severe acute respiratory syndrome virus 2 (SARS-CoV-2) transmission is an important aspect of managing the coronavirus disease 2019 (COVID-19) pandemic. In the South Korea, highly stringent infection prevention and control (IPC) guidelines are implemented, and reports of healthcare-associated SARS-CoV-2 transmission among HCWs are limited. However, subclinical infections may have been missed by the current symptom-based screening strategy. To evaluate the risk of undetected SARS-CoV-2 transmissions from COVID-19 patients to HCWs, we conducted a multicenter seroprevalence study after the first surge of the COVID-19 outbreak. A total of 432 HCWs were evaluated, comprising 309 HCWs designated to laboratory-confirmed COVID-19 patient care and 123 non-designated HCWs. Designated HCWs wore personal protective equipment including an N95 respirator, eye protection, hooded overalls, shoe covers, and inner and outer gloves. Use of a powered air-purifying respirator was recommended for aerosol-generating procedures or long-duration care activities. A high-sensitivity (99.1%) fluorescence immunoassay immunoglobulin G (IgG) kit was used as the initial screening test, and two enzyme-linked immunosorbent assay kits for total and IgG antibodies were used to confirm the test results. A microneutralization test was additionally performed to evaluate the neutralizing activity of positive specimens. Among the evaluated HCWs, none of the non-designated HCWs had a positive result, while one of the HCWs designated for COVID-19 patient care (1/309, 0.3%) was seropositive for SARS-CoV-2 with confirmed neutralizing activity (1:40). This finding suggests that subclinical seroconversion may occur among HCWs caring for COVID-19 patients, although the risk is low under strict IPC guidance.

The effect of coronavirus infection (SARS-CoV-2, MERS-CoV, and SARS-CoV) during pregnancy and the possibility of vertical maternal-fetal transmission: a systematic review and meta-analysis

BACKGROUND

Coronavirus is challenging the global health care system from time to time. The pregnant state, with alterations in hormone levels and decreased lung volumes due to a gravid uterus and slightly immunocompromised state may predispose patients to a more rapidly deteriorating clinical course and can get a greater risk of harm for both the mother and fetus. Therefore, this systematic review was aimed to assess the effect of coronavirus infection (SARS-CoV-2, MERS-CoV, and SARS-CoV) during pregnancy and its possibility of vertical maternal-fetal transmission.

METHODS

A systematic search was conducted on PubMed, Web of Science, Embase, Google Scholar and the Cochrane Library until the end of April. All authors independently extracted all necessary data using excel spreadsheet form. Only published articles with fully accessible data on pregnant women infected with SARS-CoV, MARS-CoV, and SARS-CoV-2 were included. Data on clinical manifestations, maternal and perinatal outcomes were extracted and analyzed.

RESULT

Out of 879 articles reviewed, 39 studies involving 1316 pregnant women were included. The most common clinical features were fever, cough, and myalgia with prevalence ranging from 30 to 97%, while lymphocytopenia and C-reactive protein were the most common abnormal laboratory findings (55-100%). Pneumonia was the most diagnosed clinical symptom of COVID-19 and non-COVID-19 infection with prevalence ranged from 71 to 89%. Bilateral pneumonia (57.9%) and ground-glass opacity (65.8%) were the most common CT imaging reported. The most common treatment options used were hydroxychloroquine (79.7%), ribavirin (65.2%), and oxygen therapy (78.8%). Regarding maternal outcome, the rate of preterm birth < 37 weeks of gestation was 14.3%, preeclampsia (5.9%), miscarriage (14.5%, preterm premature rupture of membranes (9.2%) and fetal growth restriction (2.8%). From the total coronavirus infected pregnant women, 56.9% delivered by cesarean, 31.3% admitted to ICU, while 2.7% were died. Among the perinatal outcomes, fetal distress rated (26.5%), neonatal asphyxia rated (1.4%). Only, 1.2% of neonates had apgar score < 7 at 5 min. Neonate admitted to ICU was rated 11.3%, while the rate of perinatal death was 2.2%. In the current review, none of the studies reported transmission of CoV from the mother to the fetus in utero during the study period.

CONCLUSION

Coronavirus infection is more likely to affect pregnant women. Respiratory infectious diseases have demonstrated an increased risk of adverse maternal obstetrical complications than the general population due to physiological changes occurred during pregnancy. None of the studies reported transmission of CoV from the mother to the fetus in utero, which may be due to a very low expression of angiotensin-converting enzyme-2 in early maternal-fetal interface cells.

Safe surgical tracheostomy during the COVID-19 pandemic: A protocol based on experiences with Middle East Respiratory Syndrome and COVID-19 outbreaks in South Korea

BACKGROUND

A subset of patients with COVID-19 require intensive respiratory care and tracheostomy. Several guidelines on tracheostomy procedures and care of tracheostomized patients have been introduced. In addition to these guidelines, further details of the procedure and perioperative care would be helpful. The purpose of this study is to describe our experience and tracheostomy protocol for patients with MERS or COVID-19.

MATERIALS AND METHODS

Thirteen patients with MERS were admitted to the ICU, 9 (69.2%) of whom underwent surgical tracheostomy. During the COVID-19 outbreak, surgical tracheostomy was performed in one of seven patients with COVID-19. We reviewed related documents and collected information through interviews with healthcare workers who had participated in designing a tracheostomy protocol.

RESULTS

Compared with previous guidelines, our protocol consisted of enhanced PPE, simplified procedures (no limitation in the use of electrocautery and wound suction, no stay suture, and delayed cannula change) and a validated screening strategy for healthcare workers. Our protocol allowed for all associated healthcare workers to continue their routine clinical work and daily life. It guaranteed safe return to general patient care without any related complications or nosocomial transmission during the MERS and COVID-19 outbreaks.

CONCLUSION

Our protocol and experience with tracheostomies for MERS and COVID-19 may be helpful to other healthcare workers in building an institutional protocol optimized for their own COVID-19 situation.

Infection Prevention Measures for Surgical Procedures during a Middle East Respiratory Syndrome Outbreak in a Tertiary Care Hospital in South Korea

In 2015, we experienced the largest in-hospital Middle East respiratory syndrome (MERS) outbreak outside the Arabian Peninsula. We share the infection prevention measures for surgical procedures during the unexpected outbreak at our hospital. We reviewed all forms of related documents and collected information through interviews with healthcare workers of our hospital. After the onset of outbreak, a multidisciplinary team devised institutional MERS-control guidelines. Two standard operating rooms were converted to temporary negative-pressure rooms by physically decreasing the inflow air volume (−4.7 Pa in the main room and −1.2 Pa in the anteroom). Healthcare workers were equipped with standard or enhanced personal protective equipment according to the MERS-related patient’s profile and symptoms. Six MERS-related patients underwent emergency surgery, including four MERS-exposed and two MERS-confirmed patients. Negative conversion of MERS-CoV polymerase chain reaction tests was noticed for MERS-confirmed patients before surgery. MERS-exposed patients were also tested twice preoperatively, all of which were negative. All operative procedures in MERS-related patients were performed without specific adverse events or perioperative MERS transmission. Our experience with setting up a temporary negative-pressure operation room and our conservative approach for managing MERS-related patients can be referred in cases of future unexpected MERS outbreaks in non-endemic countries.

A Middle East respiratory syndrome screening clinic for health care personnel during the 2015 Middle East respiratory syndrome outbreak in South Korea: A single-center experience

BACKGROUND

Transmission of Middle East respiratory syndrome (MERS) to health care personnel (HCP) is a major concern. This study aimed to review cases of MERS-related events, such as development of MERS-like symptoms or exposure to patients.

METHODS

A MERS screening clinic (MSC) for HCP was setup in the National Medical Center during the MERS outbreak in 2015. Clinical and laboratory data from HCP who visited the MSC were retrospectively reviewed. Additionally, these data were compared with the results of postoutbreak questionnaire surveys and interviews about MERS-related symptoms and risk-related events.

RESULTS

Of the 333 HCP who participated in MERS patient care, 35 HCP (10.5%) visited the MSC for MERS-like symptoms. No one was infected with MERS, and the most common symptom was fever (68.6%) followed by cough (34.3%). However, 106 of 285 postoutbreak survey participants experienced at least 1 MERS-related symptom and 26 reported exposure to patients without appropriate personal protective equipment, whereas only 4 HCP visited the MSC to report exposure events.

CONCLUSIONS

Although a considerable number of HCP experienced MERS-related symptoms or unprotected exposure during MERS patient care, some did not take appropriate action. These findings imply that for infection control strategy to be properly performed, education should be strengthened so that HCP can accurately recognize the risk situation and properly notify the infection control officer.

Middle East respiratory syndrome: what we learned from the 2015 outbreak in the Republic of Korea

Middle East Respiratory Syndrome coronavirus (MERS-CoV) was first isolated from a patient with severe pneumonia in 2012. The 2015 Korea outbreak of MERSCoV involved 186 cases, including 38 fatalities. A total of 83% of transmission events were due to five superspreaders, and 44% of the 186 MERS cases were the patients who had been exposed in nosocomial transmission at 16 hospitals. The epidemic lasted for 2 months and the government quarantined 16,993 individuals for 14 days to control the outbreak. This outbreak provides a unique opportunity to fill the gap in our knowledge of MERS-CoV infection. Therefore, in this paper, we review the literature on epidemiology, virology, clinical features, and prevention of MERS-CoV, which were acquired from the 2015 Korea outbreak of MERSCoV.

MERS-CoV Infection in a Pregnant Woman in Korea

Middle East respiratory syndrome (MERS) is a lethal respiratory disease - caused by MERS-coronavirus (MERS-CoV) which was first identified in 2012. Especially, pregnant women can be expected as highly vulnerable candidates for this viral infection. In May 2015, this virus was spread in Korea and a pregnant woman was confirmed with positive result of MERS-CoV polymerase chain reaction (PCR). Her condition was improved only with conservative treatment. After a full recovery of MERS, the patient manifested abrupt vaginal bleeding with rupture of membrane. Under an impression of placenta abruption, an emergent cesarean section was performed. Our team performed many laboratory tests related to MERS-CoV and all results were negative. We report the first case of MERS-CoV infection during pregnancy occurred outside of the Middle East. Also, this case showed relatively benign maternal course which resulted in full recovery with subsequent healthy full-term delivery without MERS-CoV transmission.

Serologic responses of 42 MERS-coronavirus-infected patients according to the disease severity

We evaluated serologic response of 42 Middle East respiratory syndrome coronavirus (MERS-CoV)-infected patients according to 4 severity groups: asymptomatic infection (Group 0), symptomatic infection without pneumonia (Group 1), pneumonia without respiratory failure (Group 2), and pneumonia progressing to respiratory failure (Group 3). None of the Group 0 patients showed seroconversion, while the seroconversion rate gradually increased with increasing disease severity (0.0%, 60.0%, 93.8%, and 100% in Group 0, 1, 2, 3, respectively; P = 0.001). Group 3 patients showed delayed increment of antibody titers during the fourth week, while Group 2 patients showed robust increment of antibody titer during the third week. Among patients having pneumonia, 75% of deceased patients did not show seroconversion by the third week, while 100% of the survived patients were seroconverted (P = 0.003).

Suggested new breakpoints of anti-MERS-CoV antibody ELISA titers: performance analysis of serologic tests

To provide optimal cut-off values of anti-Middle East respiratory syndrome coronavirus (MERS-CoV) serologic tests, we evaluated performance of ELISA IgG, ELISA IgA, IFA IgM, and IFA IgG using 138 serum samples of 49 MERS-CoV-infected patients and 219 serum samples of 219 rRT-PCR-negative MERS-CoV-exposed healthcare personnel and patients. The performance analysis was conducted for two different purposes: (1) prediction of neutralization activity in MERS-CoV-infected patients, and (2) epidemiologic surveillance of MERS-CoV infections among MERS-CoV-exposed individuals. To evaluate performance according to serum collection time, we used ‘days post onset of illness (dpoi)’ and ‘days post exposure (dpex)’ assessing neutralization activity and infection diagnosis, respectively. Performance of serologic tests improved with delayed sampling time, being maximized after a seroconversion period. In predicting neutralization activity, ELISA IgG tests showed optimal performance using sera collected after 21 dpoi at cut-off values of OD ratio 0.4 (sensitivity 100% and specificity 100%), and ELISA IgA showed optimal performance using sera collected after 14 dpoi at cut-off value of OD ratio 0.2 (sensitivity 85.2% and specificity 100%). In diagnosis of MERS-CoV infection, ELISA IgG exhibited optimal performance using sera collected after 28 dpex, at a cut-off value of OD ratio 0.2 (sensitivity 97.3% and specificity 92.9%). These new breakpoints are markedly lower than previously suggested values (ELISA IgG OD ratio 1.1, sensitivity 34.8% and specificity 100% in the present data set), and the performance data help serologic tests to be practically used in the field of MERS management.