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1.
Clin Infect Dis ; 2021 Aug 06.
Article in English | MEDLINE | ID: covidwho-1707710

ABSTRACT

BACKGROUND: Multiple SARS-CoV-2 superspreading events suggest that aerosols play an important role in driving the COVID-19 pandemic. To better understand how airborne SARS-CoV-2 transmission occurs, we sought to determine viral loads within coarse (>5µm) and fine (≤5µm) respiratory aerosols produced when breathing, talking, and singing. METHODS: Using a G-II exhaled breath collector, we measured viral RNA in coarse and fine respiratory aerosols emitted by COVID-19 patients during 30 minutes of breathing, 15 minutes of talking, and 15 minutes of singing. RESULTS: Thirteen participants (59%) emitted detectable levels of SARS-CoV-2 RNA in respiratory aerosols, including 3 asymptomatic and 1 presymptomatic patient. Viral loads ranged from 63-5,821 N gene copies per expiratory activity per participant, with high person-to-person variation. Patients earlier in illness were more likely to emit detectable RNA. Two participants, sampled on day 3 of illness, accounted for 52% of the total viral load. Overall, 94% of SARS-CoV-2 RNA copies were emitted by talking and singing. Interestingly, 7 participants emitted more virus from talking than singing. Overall, fine aerosols constituted 85% of the viral load detected in our study. Virus cultures were negative. CONCLUSIONS: Fine aerosols produced by talking and singing contain more SARS-CoV-2 copies than coarse aerosols and may play a significant role in SARS-CoV-2 transmission. Exposure to fine aerosols, especially indoors, should be mitigated. Isolating viable SARS-CoV-2 from respiratory aerosol samples remains challenging, and whether this can be more easily accomplished for emerging SARS-CoV-2 variants is an urgent enquiry necessitating larger-scale studies.

3.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-324613

ABSTRACT

Background: Post viral anosmia has been reported in human coronavirus infections. In this current pandemic, olfactory dysfunction (OD) has emerged as a common key presenting symptom of COVID-19 infection. In this study, we describe OD assessment in the inpatient setting of patients both suspected of and with confirmed COVID-19 infection via University of Pennsylvania Smell Identification Test (UPSIT) objective assessment and a simple self-reported 3-item questionnaire. Methods: Thirty patients admitted to the isolation wards of the National University Hospital, Singapore for either suspected or confirmed COVID-19 infection from April to May 2020 were recruited to this study. 10 patients who tested negative for SARS-CoV-2 were recruited as control subjects. The 20 patients with COVID-19 infection were divided into two groups (10 had olfactory testing performed during the first week of illness, 10 in the second week of illness). A simple 3-question survey was administered to each participant - to rank the severity, state the onset and duration of their hyposmia. Olfactory testing was performed using an English version of the UPSIT. Results: Loss of smell was reported in 2 participants from the control group, 6 participants from the in the first week of illness and 5 participants from the second week of illness. Two COVID-19 patients have anosmia on the UPSIT. COVID-19 patients were more likely to have severe hyposmia or anosmia by objective assessment, a difference that was statistically significant ( P = 0.0485). The differences in degree of OD among COVID-19 patients in their first and second week of illness were not statistically significant ( P = 0.6563). Conclusion: Self-reported anosmia was higher among COVID-19 patients compared to controls who were admitted to isolation wards for respiratory symptoms but were tested negative for SARS-CoV-2 infection. On objective assessment by the UPSIT, COVID-19 patients were found to have higher rates of severe hyposmia or anosmia, a difference that was statistically significant ( P = 0.0485). A limitation of this study is the odorants used in UPSIT which may be less familiar to the primarily Asian participants in this study, owing to cultural differences.

4.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-322990

ABSTRACT

Background: Multiple neurological manifestations have been associated with acute Coronavirus disease 2019 (COVID-19) infections, however the late sequelae of COVID-19 are less well described. We describe a series of consecutive young men who present with ischemic stroke in the convalescent phase of asymptomatic COVID-19 infection.Methods: We included consecutive young acute ischemic stroke patients (≤50 years old) with laboratory confirmed COVID-19 infections based on positive SARS-CoV-2 serology, without any respiratory symptoms. We reviewed their clinical course, imaging, and laboratory findings.Findings: Eighteen young male patients, aged 35-50 years old, who were diagnosed with asymptomatic COVID-19 based on positive SARS-CoV-2 serology, presented with acute ischemic stroke from 21 May 2020 to 14 October 2020. The median time from positive serology to stroke was 54·5 days (range 0-130). The median age of the patients was 41 (range 35-50), with a median National Institutes of Health Stroke Scale of five (range 1-25). Ten (55·6%) patients presented with large vessel occlusions, of which 6 patients underwent acute recanalization treatment. Only three patients had a possible cardiac source of embolus. The annual incidence rate ischemic stroke was 2·16 (95% CI 1·36 – 3·48, p<0.001) times more compared to an age, sex, ethnicity-matched historical cohort.Interpretation: Eighteen young patients, with laboratory confirmed COVID-19, presented with acute ischemic strokes in the convalescent period. We report what could be the next wave of complications from the COVID-19 pandemic. Larger prospective studies are needed to identify young patients with cryptogenic stroke who may have had COVID-19 infections.Funding: There was no funding for this study.Declaration of Interests: No authors report any conflict of interest related to this study.Ethics Approval Statement: The study was approved by our institutional ethics review board and a waiver of consent was permitted in view of the observational nature of the study.

5.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-315787

ABSTRACT

Background: Haematological markers such as absolute lymphopenia has been associated with severe COVID-19 infection. However, the described cohorts were generally unwell with a large proportion of patients requiring intensive care stay. It is uncertain if these markers apply to a population with less severe illness. We sought to describe the haematological profile of patients with mild disease with COVID-19 that were admitted to a single centre in Singapore. Methods: We examined 554 consecutive PCR positive SARS-COV-2 patients who were admitted to a single tertiary healthcare institution from Feb 2020 to April 2020 2020. We examined patients based on their haematological profile based on full blood count obtained within 24h of presentation. Results: Patients with pneumonia had higher neutrophil percentages (66.5±11.6 vs 55.2±12.6%, p<0.001), lower absolute lymphocyte count (1.5±1.1 vs 1.9±2.1 x109/L, p<0.011) and absolute eosinophil count (0.2±0.9 vs 0.7±1.8 x109/L, p=0.002). Platelet counts (210±56 vs 230±61, p=0.020) were slightly lower in the group with pneumonia. We did not demonstrate significant differences in the neutrophil-lymphocyte ratio, lymphocyte-monocyte ratio and platelet-lymphocyte ratio in patients with or without pneumonia. Sixty-eight patients (12.3%) had peripheral eosinophilia. This was more common in migrant workers living in dormitories. Conclusion: Neutrophilia and lymphopenia were found to be markers associated with severe COVID-19 illness. We did not find that combined haematological parameters: NLR, MLR and PLR, had any association with disease severity in our cohort of patients with mild-moderate disease. Migrant workers living in dormitories had eosinophilia which may reflect concurrent chronic parasitic infection.

6.
F S Sci ; 3(1): 29-34, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1671309

ABSTRACT

OBJECTIVE: To confirm if severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be detected in semen of men with acute coronavirus disease 2019 and if their male hormone profile (testosterone, follicle-stimulating hormone, luteinizing hormone, sex hormone binding globulin, and free androgen index) is adversely affected during the acute phase of infection and any relation to the ACE2 and/or TMPRSS2 expression in human semen. DESIGN: Clinical study. SETTING: National University Hospital, Singapore. PATIENTS: Asian men aged 21-55 years who were admitted to National University Hospital, Singapore, with a laboratory-confirmed diagnosis of SARS-CoV-2 infection via nasopharyngeal swab in the acute phase of the infection, within 2-14 days of the development of symptoms or contact history, were recruited for the study. INTERVENTIONS: Blood was collected in the morning to assess the male hormone profile. Human semen were obtained by masturbation and sent to the molecular diagnostic laboratories to detect the presence of SARS-CoV-2 RNA and assess the ACE2 and TMPRSS2 expression. MAIN OUTCOME MEASURES: Male hormone profile level and expression of SARS-CoV-2 RNA, ACE2, and TMPRSS2 in human semen. RESULTS: A total of 63 men of Asian ethnicities agreed to participate in the study. Subsequently, 65% of recruited men had completely normal levels of male hormone profile. Moreover, 27% were noted to have higher luteinizing hormone levels between 6.6 and 16.1 IU/L (normal range, 0.8-6.1 IU/L), and 10% had higher follicle-stimulating hormone levels between 13.6 and 41.6 IU/L (normal range, 1.5-12.4 IU/L); all had normal testosterone levels. No SARS-CoV-2 RNAs were detected in all human semen. The ACE2 and TMPRSS2 expression was undetectable in 26 samples, whereas 23 samples only had a detectable TMPRSS2 expression and 4 only had an ACE2 expression. The remaining 3 expressed both ACE2 and TMPRSS2. CONCLUSIONS: Severe acute respiratory syndrome coronavirus 2 could not be found in the semen of a cohort of young to middle-aged Asian men with mild acute SARS-CoV-2 infection. However, there was a detectable expression of ACE2 and TMPRSS2 in semen, although not causal, and it may be correlated to changes in male hormone profiles and male age.


Subject(s)
COVID-19 , SARS-CoV-2 , Angiotensin-Converting Enzyme 2/genetics , Female , Follicle Stimulating Hormone , Humans , Luteinizing Hormone , Male , Middle Aged , RNA, Viral , Seeds , Serine Endopeptidases/genetics , Testosterone
7.
Hematology ; 26(1): 1007-1012, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1555722

ABSTRACT

BACKGROUND: Haematological markers such as absolute lymphopenia have been associated with severe COVID-19 infection. However, in the literature to date, the cohorts described have typically included patients who were moderate to severely unwell with pneumonia and who required intensive care stay. It is uncertain if these markers apply to a population with less severe illness. We sought to describe the haematological profile of patients with mild disease with COVID-19 admitted to a single centre in Singapore. METHODS: We examined 554 consecutive PCR positive SARS-COV-2 patients admitted to a single tertiary healthcare institution from Feb 2020 to April 2020. In all patients a full blood count was obtained within 24 h of presentation. RESULTS: Patients with pneumonia had higher neutrophil percentages (66.5 ± 11.6 vs 55.2 ± 12.6%, p < 0.001), lower absolute lymphocyte count (1.5 ± 1.1 vs 1.9 ± 2.1 x109/L, p < 0.011) and absolute eosinophil count (0.2 ± 0.9 vs 0.7 ± 1.8 × 109/L, p = 0.002). Platelet counts (210 ± 56 vs 230 ± 61, p = 0.020) were slightly lower in the group with pneumonia. We did not demonstrate significant differences in the neutrophil-lymphocyte ratio, monocyte-lymphocyte ratio and platelet-lymphocyte ratio in patients with or without pneumonia. Sixty-eight patients (12.3%) had peripheral eosinophilia. This was more common in migrant workers living in dormitories. CONCLUSION: Neutrophilia and lymphopenia were found to be markers associated with severe COVID-19 illness. We did not find that combined haematological parameters: neutrophil-lymphocyte ratio, monocyte-lymphocyte ratio and platelet-lymphocyte ratio, had any association with disease severity in our cohort of patients with mild-moderate disease. Migrant workers living in dormitories had eosinophilia which may reflect concurrent chronic parasitic infection.


Subject(s)
Blood Cell Count , COVID-19/blood , Pandemics , SARS-CoV-2 , Adult , Anthelmintics/therapeutic use , Antiviral Agents/therapeutic use , COVID-19/drug therapy , COVID-19/epidemiology , Comorbidity , Diabetes Mellitus, Type 2/epidemiology , Dyslipidemias/epidemiology , Eosinophilia/epidemiology , Eosinophilia/etiology , Female , Fever/epidemiology , Fever/etiology , Housing , Humans , Hypertension/epidemiology , Hypoxia/epidemiology , Hypoxia/etiology , Male , Middle Aged , Neutrophils , Parasitic Diseases/drug therapy , Parasitic Diseases/epidemiology , Pneumonia, Viral/blood , Pneumonia, Viral/diagnostic imaging , Pneumonia, Viral/epidemiology , Singapore/epidemiology , Tertiary Care Centers/statistics & numerical data , Transients and Migrants/statistics & numerical data , Travel-Related Illness , Young Adult
8.
Prenat Diagn ; 41(8): 1018-1035, 2021 07.
Article in English | MEDLINE | ID: covidwho-1544371

ABSTRACT

There are over 50 SARS-CoV-2 candidate vaccines undergoing Phase II and III clinical trials. Several vaccines have been approved by regulatory authorities and rolled out for use in different countries. Due to concerns of potential teratogenicity or adverse effect on maternal physiology, pregnancy has been a specific exclusion criterion for most vaccine trials with only two trials not excluding pregnant women. Thus, other than limited animal studies, gradually emerging development and reproductive toxicity data, and observational data from vaccine registries, there is a paucity of reliable information to guide recommendations for the safe vaccination of pregnant women. Pregnancy is a risk factor for severe COVID-19, especially in women with comorbidities, resulting in increased rates of preterm birth and maternal morbidity. We discuss the major SARS-CoV-2 vaccines, their mechanisms of action, efficacy, safety profile and possible benefits to the maternal-fetal dyad to create a rational approach towards maternal vaccination while anticipating and mitigating vaccine-related complications. Pregnant women with high exposure risks or co-morbidities predisposing to severe COVID-19 infection should be prioritised for vaccination. Those with risk factors for adverse effects should be counselled accordingly. It is essential to support patient autonomy by shared decision-making involving a risk-benefit discussion with the pregnant woman.


Subject(s)
COVID-19 Vaccines , COVID-19/prevention & control , Pregnancy Complications, Infectious/prevention & control , SARS-CoV-2/immunology , COVID-19/immunology , Female , Humans , Pregnancy , Pregnancy Complications, Infectious/immunology , Vaccination/ethics
10.
BMC Infect Dis ; 21(1): 1094, 2021 Oct 24.
Article in English | MEDLINE | ID: covidwho-1484304

ABSTRACT

BACKGROUND: Several specific risk scores for Coronavirus disease 2019 (COVID-19) involving clinical and biochemical parameters have been developed from higher-risk patients, in addition to validating well-established pneumonia risk scores. We compared multiple risk scores in predicting more severe disease in a cohort of young patients with few comorbid illnesses. Accurately predicting the progression of COVID-19 may guide triage and therapy. METHODS: We retrospectively examined 554 hospitalised COVID-19 patients in Singapore. The CURB-65 score, Pneumonia Severity Index (PSI), ISARIC 4C prognostic score (4C), CHA2DS2-VASc score, COVID-GRAM Critical Illness risk score (COVID-GRAM), Veterans Health Administration COVID-19 index for COVID-19 Mortality (VACO), and the "rule-of-6" score were compared for three performance characteristics: the need for supplemental oxygen, intensive care admission and mechanical ventilation. RESULTS: A majority of patients were young (≤ 40 years, n = 372, 67.1%). 57 (10.3%) developed pneumonia, with 16 (2.9% of study population) requiring supplemental oxygen. 19 patients (3.4%) required intensive care and 2 patients (0.5%) died. The clinical risk scores predicted patients who required supplemental oxygenation and intensive care well. Adding the presence of fever to the CHA2DS2-VASc score and 4C score improved the ability to predict patients who required supplemental oxygen (c-statistic 0.81, 95% CI 0.68-0.94; and 0.84, 95% CI 0.75-0.94 respectively). CONCLUSION: Simple scores including well established pneumonia risk scores can help predict progression of COVID-19. Adding the presence of fever as a parameter to the CHA2DS2-VASc or the 4C score improved the performance of these scores in a young population with few comorbidities.


Subject(s)
COVID-19 , Hospital Mortality , Humans , Retrospective Studies , Risk Assessment , Risk Factors , SARS-CoV-2 , Severity of Illness Index
11.
Medicine (Baltimore) ; 100(30): e26719, 2021 Jul 30.
Article in English | MEDLINE | ID: covidwho-1475908

ABSTRACT

ABSTRACT: Liver dysfunction in patients with COVID-19 (coronavirus disease 2019) has been described. However, it is not clear if the presence of abnormal liver function tests at presentation was related to underlying undiagnosed liver disease, or a result of the viral infection.We retrospectively examined the first 554 consecutive polymerase chain reaction positive SARS-CoV-2 patients admitted from February 2020 to April 2020 to our academic medical centre. We reviewed their clinical data, chest radiography and laboratory studies obtained within 24 hour of admission.Despite similar hemodynamic parameters, we found significant aspartate transaminase elevation (64 ±â€Š141 vs 35 ±â€Š23 U/L, P < .001) in those with pneumonia compared to those without. Elevated liver enzymes were seen in 102 patients (18.4%). They presented with higher temperatures (38.5 ±â€Š0.9 vs 37.5 ±â€Š0.8 degC, P = .011), higher total white cell counts (6.95 ±â€Š2.29 vs 6.39 ±â€Š2.19 x109/L, P = .021), serum ferritin (240 ±â€Š274 vs 165 ±â€Š198 ng/ml, P = .002) and lactate dehydrogenase (632 ±â€Š912 vs 389 ±â€Š107 U/L, P < .001). These patients were more likely to require intensive care (6.9% vs 2.7% P = .036) and mechanical ventilation (5.9% vs 2.2%, P = .046). Migrant workers from dormitories had a higher rate of baseline liver function test abnormalities (88/425 vs 14/129, P = .01), which were more likely to persist at the time of discharge.Despite relatively mild COVID-19 disease, there was a significant prevalence of liver dysfunction, particularly amongst migrant workers. Elevated liver enzymes were associated with more severe disease, despite similar haemodynamic characteristics. Future studies should explore whether pre-existing liver disease may predispose to more severe COVID-19 disease.


Subject(s)
Aspartate Aminotransferases/blood , COVID-19/complications , L-Lactate Dehydrogenase/blood , Liver Diseases/etiology , Adult , COVID-19/blood , Female , Ferritins/blood , Humans , Leukocyte Count , Liver Diseases/blood , Liver Function Tests , Male , Middle Aged , Retrospective Studies , Risk Factors , Singapore
13.
Nature ; 584(7821): 457-462, 2020 08.
Article in English | MEDLINE | ID: covidwho-1373437

ABSTRACT

Memory T cells induced by previous pathogens can shape susceptibility to, and the clinical severity of, subsequent infections1. Little is known about the presence in humans of pre-existing memory T cells that have the potential to recognize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here we studied T cell responses against the structural (nucleocapsid (N) protein) and non-structural (NSP7 and NSP13 of ORF1) regions of SARS-CoV-2 in individuals convalescing from coronavirus disease 2019 (COVID-19) (n = 36). In all of these individuals, we found CD4 and CD8 T cells that recognized multiple regions of the N protein. Next, we showed that patients (n = 23) who recovered from SARS (the disease associated with SARS-CoV infection) possess long-lasting memory T cells that are reactive to the N protein of SARS-CoV 17 years after the outbreak of SARS in 2003; these T cells displayed robust cross-reactivity to the N protein of SARS-CoV-2. We also detected SARS-CoV-2-specific T cells in individuals with no history of SARS, COVID-19 or contact with individuals who had SARS and/or COVID-19 (n = 37). SARS-CoV-2-specific T cells in uninfected donors exhibited a different pattern of immunodominance, and frequently targeted NSP7 and NSP13 as well as the N protein. Epitope characterization of NSP7-specific T cells showed the recognition of protein fragments that are conserved among animal betacoronaviruses but have low homology to 'common cold' human-associated coronaviruses. Thus, infection with betacoronaviruses induces multi-specific and long-lasting T cell immunity against the structural N protein. Understanding how pre-existing N- and ORF1-specific T cells that are present in the general population affect the susceptibility to and pathogenesis of SARS-CoV-2 infection is important for the management of the current COVID-19 pandemic.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/immunology , Pneumonia, Viral/immunology , Severe Acute Respiratory Syndrome/immunology , T-Lymphocytes/immunology , Betacoronavirus/chemistry , COVID-19 , Case-Control Studies , Coronavirus Infections/virology , Coronavirus Nucleocapsid Proteins , Cross Reactions/immunology , Humans , Immunodominant Epitopes/immunology , Nucleocapsid Proteins/chemistry , Nucleocapsid Proteins/immunology , Pandemics , Phosphoproteins , Pneumonia, Viral/virology , SARS-CoV-2
14.
NPJ Vaccines ; 6(1): 105, 2021 Aug 19.
Article in English | MEDLINE | ID: covidwho-1366818

ABSTRACT

Lactating women can produce protective antibodies in their milk after vaccination, which has informed antenatal vaccination programs for diseases such as influenza and pertussis. However, whether SARS-CoV-2-specific antibodies are produced in human milk as a result of COVID-19 vaccination is still unclear. In this study, we show that lactating mothers who received the BNT162b2 vaccine secreted SARS-CoV-2-specific IgA and IgG antibodies into milk, with the most significant increase at 3-7 days post-dose 2. Virus-specific IgG titers were stable out to 4-6 weeks after dose 2. In contrast, SARS-CoV-2-specific IgA levels showed substantial decay. Vaccine mRNA was detected in few milk samples (maximum of 2 ng/ml), indicative of minimal transfer. Additionally, infants who consumed post-vaccination human milk had no reported adverse effects up to 28 days post-ingestion. Our results define the safety and efficacy profiles of the vaccine in this demographic and provide initial evidence for protective immunity conferred by milk-borne SARS-CoV-2-specific antibodies. Taken together, our study supports recommendations for uninterrupted breastfeeding subsequent to mRNA vaccination against COVID-19.

15.
Medicine (Baltimore) ; 100(30): e26719, 2021 Jul 30.
Article in English | MEDLINE | ID: covidwho-1345775

ABSTRACT

ABSTRACT: Liver dysfunction in patients with COVID-19 (coronavirus disease 2019) has been described. However, it is not clear if the presence of abnormal liver function tests at presentation was related to underlying undiagnosed liver disease, or a result of the viral infection.We retrospectively examined the first 554 consecutive polymerase chain reaction positive SARS-CoV-2 patients admitted from February 2020 to April 2020 to our academic medical centre. We reviewed their clinical data, chest radiography and laboratory studies obtained within 24 hour of admission.Despite similar hemodynamic parameters, we found significant aspartate transaminase elevation (64 ±â€Š141 vs 35 ±â€Š23 U/L, P < .001) in those with pneumonia compared to those without. Elevated liver enzymes were seen in 102 patients (18.4%). They presented with higher temperatures (38.5 ±â€Š0.9 vs 37.5 ±â€Š0.8 degC, P = .011), higher total white cell counts (6.95 ±â€Š2.29 vs 6.39 ±â€Š2.19 x109/L, P = .021), serum ferritin (240 ±â€Š274 vs 165 ±â€Š198 ng/ml, P = .002) and lactate dehydrogenase (632 ±â€Š912 vs 389 ±â€Š107 U/L, P < .001). These patients were more likely to require intensive care (6.9% vs 2.7% P = .036) and mechanical ventilation (5.9% vs 2.2%, P = .046). Migrant workers from dormitories had a higher rate of baseline liver function test abnormalities (88/425 vs 14/129, P = .01), which were more likely to persist at the time of discharge.Despite relatively mild COVID-19 disease, there was a significant prevalence of liver dysfunction, particularly amongst migrant workers. Elevated liver enzymes were associated with more severe disease, despite similar haemodynamic characteristics. Future studies should explore whether pre-existing liver disease may predispose to more severe COVID-19 disease.


Subject(s)
Aspartate Aminotransferases/blood , COVID-19/complications , L-Lactate Dehydrogenase/blood , Liver Diseases/etiology , Adult , COVID-19/blood , Female , Ferritins/blood , Humans , Leukocyte Count , Liver Diseases/blood , Liver Function Tests , Male , Middle Aged , Retrospective Studies , Risk Factors , Singapore
16.
Clin Infect Dis ; 2021 Aug 06.
Article in English | MEDLINE | ID: covidwho-1345720

ABSTRACT

BACKGROUND: Multiple SARS-CoV-2 superspreading events suggest that aerosols play an important role in driving the COVID-19 pandemic. To better understand how airborne SARS-CoV-2 transmission occurs, we sought to determine viral loads within coarse (>5µm) and fine (≤5µm) respiratory aerosols produced when breathing, talking, and singing. METHODS: Using a G-II exhaled breath collector, we measured viral RNA in coarse and fine respiratory aerosols emitted by COVID-19 patients during 30 minutes of breathing, 15 minutes of talking, and 15 minutes of singing. RESULTS: Thirteen participants (59%) emitted detectable levels of SARS-CoV-2 RNA in respiratory aerosols, including 3 asymptomatic and 1 presymptomatic patient. Viral loads ranged from 63-5,821 N gene copies per expiratory activity per participant, with high person-to-person variation. Patients earlier in illness were more likely to emit detectable RNA. Two participants, sampled on day 3 of illness, accounted for 52% of the total viral load. Overall, 94% of SARS-CoV-2 RNA copies were emitted by talking and singing. Interestingly, 7 participants emitted more virus from talking than singing. Overall, fine aerosols constituted 85% of the viral load detected in our study. Virus cultures were negative. CONCLUSIONS: Fine aerosols produced by talking and singing contain more SARS-CoV-2 copies than coarse aerosols and may play a significant role in SARS-CoV-2 transmission. Exposure to fine aerosols, especially indoors, should be mitigated. Isolating viable SARS-CoV-2 from respiratory aerosol samples remains challenging, and whether this can be more easily accomplished for emerging SARS-CoV-2 variants is an urgent enquiry necessitating larger-scale studies.

17.
Infect Chemother ; 53(2): 391-394, 2021 Jun.
Article in English | MEDLINE | ID: covidwho-1295981

ABSTRACT

There have been recent descriptions of the novel coronavirus disease 2019 (COVID-19) presenting as 'varicella-like exanthem'. We report three cases of patients with Varicella-Zoster Virus (VZV) and COVID-19 co-infections, presenting in three varied ways. These cases highlight the need for heightened alertness to how such co-infections can present, to pick up overlapping 'dual pathologies' during this current pandemic given that infection control measures including airborne precautions are crucial for both COVID-19 and VZV.

18.
Int J Infect Dis ; 106: 314-322, 2021 May.
Article in English | MEDLINE | ID: covidwho-1279607

ABSTRACT

BACKGROUND: We examined whether existing licensed pharmacotherapies could reduce the spread of coronavirus disease 2019 (COVID-19). METHODS: An open-label parallel randomized controlled trial was performed among healthy migrant workers quarantined in a large multi-storey dormitory in Singapore. Forty clusters (each defined as individual floors of the dormitory) were randomly assigned to receive a 42-day prophylaxis regimen of either oral hydroxychloroquine (400 mg once, followed by 200 mg/day), oral ivermectin (12 mg once), povidone-iodine throat spray (3 times/day, 270 µg/day), oral zinc (80 mg/day)/vitamin C (500 mg/day) combination, or oral vitamin C, 500 mg/day. The primary outcome was laboratory evidence of SARS-CoV-2 infection as shown by either: (1) a positive serologic test for SARS-CoV-2 antibody on day 42, or (2) a positive PCR test for SARS-CoV-2 at any time between baseline and day 42. RESULTS: A total of 3037 asymptomatic participants (mean age, 33.0 years; all men) who were seronegative to SARS-CoV-2 at baseline were included in the primary analysis. Follow-up was nearly complete (99.6%). Compared with vitamin C, significant absolute risk reductions (%, 98.75% confidence interval) were observed for oral hydroxychloroquine (21%, 2-42%) and povidone-iodine throat spray (24%, 7-39%). No statistically significant differences were observed with oral zinc/vitamin C combination (23%, -5 to +41%) and ivermectin (5%, -10 to +22%). Interruptions due to side effects were highest among participants who received zinc/vitamin C combination (6.9%), followed by vitamin C (4.7%), povidone-iodine (2.0%), and hydroxychloroquine (0.7%). CONCLUSIONS: Chemoprophylaxis with either oral hydroxychloroquine or povidone-iodine throat spray was superior to oral vitamin C in reducing SARS-CoV-2 infection in young and healthy men.


Subject(s)
COVID-19/prevention & control , Hydroxychloroquine/pharmacology , Pharynx , Povidone-Iodine/pharmacology , Adult , Humans , Male , Middle Aged , Time Factors , Treatment Outcome , Young Adult
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