Biology HSC HSC Practice Question 6a – Evaluate quarantine and environmental control methods

In the coastal city of Port Azure a novel respiratory virus, designated N10, has been detected. Epidemiological and environmental data gathered in the first week are as follows:

• Estimated basic reproduction number R0 ≈ 2.4.
• Incubation period typically 4–7 days; infectiousness begins on average 1 day before symptom onset.
• Approximately 30% of infected individuals remain asymptomatic but can transmit the virus.
• Aerosolized N10 remains viable and potentially infectious in air for up to 8 hours in enclosed spaces under current measured conditions.
• N10 remains detectable and viable on common touch surfaces (plastic/metal) for up to 48 hours.
• Wastewater monitoring in the city sewage network detects N10 RNA and has historically shown a rise in wastewater signal about 3 days before an increase in clinically detected cases.

Local public-health authorities are considering a mixture of interventions: (1) targeted quarantine of laboratory-confirmed cases and their household contacts; (2) a short-term citywide lockdown; (3) mandatory HEPA filtration and ventilation upgrades in public buildings and transport hubs; (4) routine UV-C surface disinfection in high-traffic areas; and (5) enhanced wastewater surveillance to provide early warning of rising community transmission.

The following parts ask you to evaluate and design control measures and monitoring strategies using the information above. Technology is allowed for calculations or brief literature look-ups but is not required.