How Do Clinical Characteristics of COVID-19 Infection Differ Between Symptomatic and Asymptomatic Patients?

BACKGROUND AND PURPOSE:

• Yang et al. (JAMA Netw Open., 2020) describe clinical characteristics of both symptomatic and asymptomatic patients with confirmed SARS-CoV-2 infection

METHODS:

• Case series (December 24, 2019, to February 24, 2020)
• Setting
  • Wuhan, China
• Participants
  • Consecutive hospitalized cases with lab confirmed COVID-19
  • Recruited from 26 cluster cases who had
    • Confirmed history of exposure to the Hunan seafood market or
    • Close contact with another patient who had been hospitalized for COVID-19
• Study design
  • RT-PCR on nasopharyngeal swabs was performed every 24 to 48 hours
  • CT scan: On admission with a second chest CT at 4 to 6 days and third CT at 6 to 7 days after the second scan
    • Additional CT for worsening status
  • CD4+T lymphocyte count was tested every 5 to 6 days

RESULTS:

• 78 patients
  • Median (IQR) number of patients per cluster: 3 (2-3) patients
  • Range: 2 to 10 patients per cluster
• Symptomatic vs asymptomatic
  • Symptomatic cases: 57.7% of cases (45 patients)
  • Asymptomatic: 42.3% of cases (33 patients)
• Patients who were asymptomatic tended to
  • Be younger (P < 0.001)
    • Asymptomatic: median (IQR) age 37 (26 to 45) years
    • Symptomatic: 56 (34 to 63) years
  • Be women (P = 0.002)
    • Asymptomatic: 66.7% were women (22 patients)
    • Symptomatic: 31.0% were women (14 patients)
  • Not have biochemical evidence of liver injury (P = 0.03)
    • Asymptomatic: 3% had a liver injury (1 patient)
    • Symptomatic: 20.0% had a liver injury (9 patients)
  • Have higher CD4+T lymphocyte counts  (P = 0.001)
    • Asymptomatic: median (IQR) 719 (538 to 963) per uL
    • Symptomatic: 474 (354 to 811) per ul
  • Have faster lung recovery based on CT scan (P = 0.001)
    • Asymptomatic: median (IQR) duration 9 (6 to 18) days
    • Symptomatic: 15 (11 to 18) days
  • Have a shorter duration of viral shedding on nasopharyngeal swabs (P = 0.001)
    • Asymptomatic: median (IQR) duration 8 (3 to 12) days
    • Symptomatic: 19 (16 to 24) days
  • Have more stable SARS-CoV-2 testing results
    • Asymptomatic: 12.1% had fluctuated results (4 patients)
    • Symptomatic: 33.3% had fluctuated results (15 patients)

CONCLUSION:

• Compared to symptomatic COVID-19 patients, asymptomatic patients experienced less organ injury and CT scans improved more rapidly
  • Consumption of CD4 lymphocytes was lower, suggesting less damage to the immune system
• Asymptomatic patients appear to have a shorter duration of viral shedding, suggesting that they may be infectious for a shorter period of time

Learn More – Primary Sources:

Comparison of Clinical Characteristics of Patients with Asymptomatic vs Symptomatic Coronavirus Disease 2019 in Wuhan, China

ICU Admission for COVID-19 and Maternal Outcomes

PURPOSE:

• Blitz et al. (AJOG, 2020), sought to determine maternal outcomes in pregnant and postpartum women admitted to the ICU with a diagnosis of COVID-19

METHODS:

• Case series of consecutive admissions (March 1 to May 6, 2020)
  • Large integrated healthcare system
  • System responsible for 40,000 deliveries per year (1% of all US births)
• Participants
  • Pregnant and postpartum women (immediately following delivery) with laboratory-confirmed COVID-19 and admitted to the ICU
• Data source
  • Extracted from electronic health record
    • Demographics | Medical comorbidities | Duration of illness prior to hospitalization | Lab results | Radiology Reports | ICU treatments and outcomes

RESULTS:

• Total of 462 pregnant women tested positive for SARS-CoV-2
  • Severe or critical: 15% (70 patients)
  • 13 of 70 patients (19%) admitted to ICU
  • Mean gestational age at hospitalization: 33.3 weeks
  • Symptom onset: 8±3 days prior to admission
• Maternal characteristics of patients admitted to ICU
  • Mean maternal age: 33.8 years
  • Multiparous: 69% | All singletons
  • Largest racial/ethnic group: Hispanic (38%)
  • Comorbidities
    • Obesity: 38%
    • Pulmonary conditions: 23% (e.g, asthma and obstructive sleep apena)
    • No comorbidities: 46%

Clinical course of patients admitted to ICU

• Common clinical findings included tachycardia (77%) and tachypnea (23%) | 02 sat <93% (69%)
• Fever was uncommon (15%)
• Common lab findings
  • Lymphopenia | Elevated transaminases | Elevated inflammatory markers
• Mechanical ventilation: 8 cases (6 postpartum; 2 pregnant)

Treatment

• Prophylactic or therapeutic anticoagulation: 100%
• Hydroxychloroquine: 85%
• Antibiotics for community acquired pneumonia: 92%
• Enrolled in remdesivir trial: 23%
• Interleukin-6 receptor inhibitors: 38%
• Convalescent plasma therapy: 15%

Maternal Mortality

• Maternal mortality: 2 patients died
• Patient 1: periviable fetal demise with multisystem organ failure
  • BMI >40 kg/m2 | Obstructive Sleep Apnea
• Patient 2: “rapid clinical deterioration postpartum”
  • No comorbidities
  • Severe respiratory distress, multiple organ failure and cardiopulmonary arrest

Pregnancy Outcomes

• Deliveries during hospitalization: 54% (7 patients) | Preterm: 4 deliveries (57%)
• Cesarean deliveries
  • Respiratory decompensation: 5 patients
  • Cord prolapse (was induced for worsening respiratory status): 1 patient
• Vaginal delivery: 1 patient

CONCLUSION:  

• 2 patients (1 pregnant, 1 postpartum) hospitalized with COVID-19 died following ICU admission
  • 15% of patients admitted to ICU and 25% of patients on mechanical ventilation  
• The authors state

…pregnant and postpartum women admitted to the ICU with COVID-19 are at risk for maternal death, which may occur even in the absence of significant baseline comorbidities

Learn More – Primary Sources:

Maternal Mortality Among Women with COVID-19 Admitted to the Intensive Care Unit