Almost half of Hong Kong’s population have been infected with Covid-19 during the fifth and worst wave of outbreak, according to the latest estimations by medical experts at the University of Hong Kong (HKU).
As of Monday, around 3.6 million people in the city had already contracted the virus as the fifth wave peaked on March 4, scholars from the Li Ka Shing Faculty of Medicine of HKU said on Tuesday. The approximation accounts for around 48 per cent of Hong Kong’s population, which totalled around 7.4 million by the end of last year.
In their eighth update on the city’s pandemic development based on epidemiology modelling, the HKU experts predicted that the number of Covid-19 cases would begin to drop towards the end of March.
The daily caseload is expected to fall below 1,000 by the end of April, and to under 100 by mid-May, if the city’s public health and social distancing measures remain unchanged.
The fifth wave is forecast to infect a total of around 4.5 million people, the scholars projected, while around 5,102 people will succumb to the virus.
Asked about the estimation by HKU, Principal Medical and Health Officer of the Communicable Disease Branch of the Centre for Health Protection Albert Au said on Tuesday it was a “reasonable figure.” He said the health authorities knew the infection figures they published did not cover all Covid-19 cases.
“Not all infected person can be found. Some were asymptomatic and some did not get tested… behind every case that we know of, there may been three or four cases,” he said.
On Tuesday, Hong Kong reported 27,765 new Covid-19 cases and 289 deaths. The fifth wave of infections, which began in January, has pushed the city’s caseload from around 12,600 to beyond 700,000 in a little over two months. Meanwhile, the death toll – which stood at 213 before the current wave – multiplied around 20-fold to surpass 4,200.
Citing public transport Octopus card data, the HKU scholars said they began to detect a slight uptick in population mobility. Such changes could affect the accuracy of the projections, they said.
“This could well portend a fundamental change in transmission dynamics that would render our assumptions inaccurate, thus underestimating the forward burden of the fifth wave,” the study read.
The study also estimated that there was an eight-day interval between the date when symptoms begin to show and death for elderly Covid-19 patients aged 70 or above who lived in residential care homes. The interval, deduced from data relating to 37 deaths and the dates of symptoms onset, was slightly longer for patients in the same age group in general, which stood at 10.5 days.
The model adopted by HKU took into account the higher risk of infection and mortality among residents of the elderly care homes. Only nine per cent of local elderly care homes have not reported a Covid-19 outbreak, according to the report, with 31 per cent of residents infected. The deaths reported from the care homes also made up 58.9 per cent of the total number of deaths recorded in the fifth wave.