Objective:

To evaluate the feasibility of decentralized respiratory virus surveillance using self-collected samples, online questionnaires, and telemedicine in a household cohort in Switzerland.

Approach:

• Study Setting and Participants: This pilot study enrolled 108 households in the canton of Bern, comprising 161 adults, 32 children, 29 cats, and 15 dogs.
• Sampling Procedures: Participants were instructed to report respiratory symptoms through an online questionnaire. Symptomatic index cases collected nasal swabs, and other household members collected samples 7 days later. Dogs underwent nasal sampling and cats underwent oropharyngeal sampling.
• Sample Handling: Participants mailed samples directly to a centralized biobank and entered the corresponding sample identification numbers on an online platform.
• Laboratory Analysis: Samples were tested for 13 respiratory viruses, including SARS-CoV-2, influenza, respiratory syncytial virus, and rhinovirus, using a commercially available CE-IVD multiplex PCR panel.
• Endpoints and Analysis: The primary endpoint was the proportion of indicated samples that were collected and analyzed. Viral positivity was compared between symptomatic index cases and mostly asymptomatic household contacts, and participants completed surveys about the acceptability of study procedures.

Key Findings:

• During 152 respiratory illness events in 78 households, 336 of 387 expected swabs (87%) were received. Seventy-six received samples were excluded because of participant protocol breaches.
• Valid results were obtained from 131 of 188 requested index-case samples (70%), 105 of 152 household-contact samples (69%), and 24 of 47 pet samples (51%).
• A respiratory virus was detected in 82 of 131 index-case samples (63%). Rhinovirus accounted for 38 of 82 positive samples (46%), followed by SARS-CoV-2 in 21 (26%).
• Among human household contacts, 24 of 105 samples (23%) contained a virus. Rhinovirus accounted for 17 of 24 positive contact samples (71%).
• Viral positivity was 60% among swabs from symptomatic participants and 6% among swabs from asymptomatic participants.
• Potential household transmission was observed in 14 rhinovirus events, 3 SARS-CoV-2 events, and 2 parainfluenza events.
• None of the 24 analyzed pet swabs was PCR-positive, despite reported close contact between participants and their pets.
• Among 96 households responding to the acceptability survey, 70% agreed that nasal sampling was not unpleasant. Eight of 10 households surveyed after an early illness event found telemedicine helpful and home sampling easy.

Interpretation:

Decentralized respiratory virus surveillance using symptom-triggered self-sampling and online reporting was feasible in this household cohort, although the proportion of requested samples yielding valid results was suboptimal. The substantially higher viral positivity among symptomatic participants supported self-reported respiratory symptoms as an indicator for initiating sample collection. The absence of positive pet samples should be interpreted cautiously because only 24 pet samples were analyzed and most viruses included in the panel were human pathogens.

Limitations:

• Approximately one-third of expected samples did not produce analyzable results because samples were not submitted or were excluded following protocol breaches.
• Some participants submitted samples incorrectly because of procedural uncertainty, limited motivation, or difficulty recording sample identification numbers.
• Valid results were available for only 51% of requested pet samples.
• The multiplex panel did not test for bacterial respiratory pathogens such as pneumococci or Mycoplasma pneumoniae.
• Most viruses included in the panel were human pathogens, limiting interpretation of negative pet results.
• The telemedicine assessment involved only 10 households that experienced an illness event during the first month.
• The study was a pilot conducted in 108 households in the canton of Bern, and it did not establish diagnostic effectiveness or effects on clinical outcomes.

Conclusion:

A decentralized household cohort using remote self-sampling and online questionnaires was feasible for respiratory virus surveillance and pandemic preparedness, but sample yield was suboptimal. Simplifying sample-identification and submission procedures may improve data completeness in larger studies. The pilot findings were intended to inform future investigations of emerging respiratory diseases.