Is home quarantine indicated for all influenza strains?

Home Quarantine for Influenza: Not Routinely Indicated for All Strains

Home quarantine is not generally recommended for routine influenza cases due to practical implications and because infections transmitted by pre-symptomatic people are rare, but early isolation at home of people feeling unwell and feverish when influenza is circulating is strongly recommended. 1

General Recommendations for Influenza Control

• Early isolation at home of people feeling unwell and feverish is recommended when influenza is circulating in the community 1, 2
• Regular handwashing and good respiratory hygiene (covering mouth and nose when coughing or sneezing) are strongly supported measures for reducing transmission 1, 2
• Mask wearing is recommended in healthcare settings for those with symptoms of acute respiratory infections 1, 2

When Quarantine May Be Considered

While routine quarantine is not generally recommended for all influenza cases, there are specific situations where more stringent isolation or quarantine measures may be appropriate:

• During a severe pandemic, voluntary household quarantine following diagnosis of influenza in a family member might be considered 1
• For institutional outbreaks in settings housing persons at high risk (e.g., nursing homes, hospitals), more aggressive control measures including isolation and quarantine may be necessary 1, 2
• When trying to stop spread in a healthcare setting 1
• When a person known to be exposed to diagnosed influenza is nearing the end of the incubation period and has planned travel where self-isolation would be impossible 1

Institutional Outbreak Control Measures

For outbreaks in institutional settings such as nursing homes or hospitals, more comprehensive control measures are recommended:

• Instituting droplet precautions and establishing cohorts of patients with confirmed or suspected influenza 1, 2
• Re-offering influenza vaccinations to unvaccinated staff and patients 1
• Restricting staff movement between wards or buildings 1
• Restricting contact between ill staff or visitors and patients 1
• Administering chemoprophylaxis to all residents regardless of vaccination status when outbreaks occur in institutions housing high-risk persons 1

Duration of Infectivity and Isolation

• Patients with influenza are typically contagious from 1 day before symptoms develop and remain infectious for approximately 5 days after symptom onset 2
• When institutional outbreaks occur, chemoprophylaxis should continue for at least 2 weeks, and if new cases continue to appear, it should be extended until approximately 1 week after the end of the outbreak 1

Special Considerations for High-Risk Populations

• More aggressive control measures may be warranted for protecting high-risk individuals, including those with chronic medical conditions, immunocompromised status, adults ≥65 years, and children <5 years 1
• Chemoprophylaxis may be considered for high-risk individuals who have been exposed to influenza, even when quarantine is not implemented 1

Practical Implications

• The European Centre for Disease Prevention and Control (ECDC) notes that general quarantine for influenza has practical challenges that limit its feasibility in most scenarios 1
• Resources required for contact tracing and enforcing quarantine make it impractical in most scenarios 3
• The focus should be on early isolation of symptomatic individuals rather than quarantine of exposed but asymptomatic persons 1, 2

Pandemic Scenarios

During a pandemic, recommendations may differ based on the severity and transmissibility of the strain:

• For lower transmissibility strains, household-based quarantine combined with isolation of cases outside the household and targeted prophylactic use of antivirals may be effective even with moderate compliance 3
• Border restrictions or internal travel restrictions are unlikely to delay spread by more than 2-3 weeks unless more than 99% effective 4
• School closure during the peak of a pandemic can reduce peak attack rates but has limited impact on overall attack rates 4

Home quarantine is not a one-size-fits-all approach for influenza control. The decision to implement quarantine measures should be based on the specific influenza strain characteristics, setting, and risk to vulnerable populations.