Coronavirus: Over 3,500 deaths, 100k cases across 100 countries; here are the numbers that define the outbreak
COVID-19 was first recognized in Wuhan, China, at the start of December 2019 and in the following two months it has grown to over 100,000 cases globally. Here are some numbers to show how much the disease has spread so far and how deadly it is.
It has spread to over 100 countries/regions
As of March 9, the disease has been diagnosed in 110,034 people and it has killed 3,825 globally.
The World Health Organization (WHO) risk assessment is very high in the case of China as well as the regional and global levels. Around one in every five people who catch COVID-19 needs hospital treatment, says the WHO.
“The global number of confirmed cases of COVID-19 has surpassed 100,000. As we mark this somber moment, the WHO reminds all countries and communities that the spread of this virus can be significantly slowed or even reversed through the implementation of robust containment and control activities,” said WHO in a statement.
On March 8, WHO Director-General Dr Tedros Adhanom Ghebreyesus tweeted that the number of countries reporting COVID-19 cases has reached 100 after the numbers crossed 100,000 and while this is very serious, “this should not discourage us.”
“Even though we are over 100,000 #COVID19 cases, this is a relatively young outbreak. We’re still learning about it,” said Dr Ghebreyesus.
For COVID-19, data to date suggest that 80% of infections are mild or asymptomatic, 15% are severe infection, requiring oxygen and five percent are critical infections, requiring ventilation. For COVID-19, the current understanding is that older age and underlying conditions increase the risk for severe infection.
The disease has spread to over 100 countries ort regions. More cases are now being reported outside China.
The WHO situation report on March 8 reported 3,610 new infections outside China and 71 new deaths. In contrast, there were 46 new infections in China and 27 new deaths.
In its update on March 9, China’s National Health Commission reported 40 new cases of confirmed infections, 60 new cases of suspected infections, and 22 deaths.
Accordingly, as per March 9 numbers over 80,000 have been sickened in China so far. In all, 58,600 patients had been cured and discharged from hospital in China, shows the latest estimates.
About one-third of residential communities in the Hubei provincial capital Wuhan, the epicenter of the novel coronavirus outbreak, have had no newly confirmed cases in the past two weeks as of March 5, according to the city's epidemic prevention and control headquarters.
Outside of China, the leading countries include South Korea, Iran, Italy, France, Germany, and the US. Globally, 61,965 have recovered from COVID-19, according to figures till March 9.
Global case fatality rate stands at 3.4% currently
The overall mortality rate of this disease is difficult to calculate because of the different ways it is being diagnosed in different countries. Also, it is too early to make any conclusive statements about what the overall mortality rate will be for the novel coronavirus.
Globally, about 3.4% of reported COVID-19 cases have died, said the World Health Organization (WHO) in their March 3 briefing.
By comparison, seasonal flu generally kills far fewer than 1% of those infected. Again, by contrast, severe acute respiratory syndrome (SARS), killed 9.6% of those infected, and Middle East respiratory syndrome (MERS) killed 34.4%.
“We believe that there is over-diagnosis or over-representation of people who are the most severely ill. We find severe cases first because they are the most obvious and they are in the hospital. That is going to skew the case fatality rates or mortality rates upwards. And the more that we do diagnose, the more that we diagnose mild cases, the more that will drive down the overall fatality rate. But it is too soon to say how far that will go,” said Dr. Inglesby is the Director of the Center for Health Security of the Johns Hopkins Bloomberg School of Public Health.
As far as China is concerned, an analysis of 1,023 deaths that occurred among 44,672 confirmed cases till February 11 showed an overall case fatality rate of 2.3%.
Subsequently, the WHO-China Joint Mission released a report in February, which estimated the case-fatality rate at between 3% and 4% nationwide in China.
According to another estimate till February 20, the overall case fatality rate varied by location and intensity of transmission -- that is, 5.8% in Wuhan versus 0.7% in other areas in China.
“In China, the overall mortality rate was higher in the early stages of the outbreak (17.3% for cases with symptom onset from January 1- 10 ) and has reduced over time to 0.7% for patients with symptom onset after February 1,” said the report.
The global fatality rate will become clear once the epidemic has run its full course, said experts.
Incubation period of 2 to 14 days
The disease has an incubation period of two to 14 days, with an average incubation of about five days. The incubation period refers to the time from exposure to the development of symptoms
According to the US CDC, symptoms such as fever, cough, and shortness of breath may appear 2-14 days after exposure.
An analysis of medical records of 138 patients showed that the median time from the first symptom to dyspnea (difficult or labored breathing) was five days, to hospital admission was seven days, and to acute respiratory distress syndrome (ARDS) was eight days. The median time from the onset of symptoms to ICU admission was 10 days.
The incubation period of SARS is usually 2-7 days but maybe as long as 10 days. In the case of MERS, the median incubation period “for secondary cases associated with limited human-to-human transmission” is approximately five days (range 2-14 days), says the WHO.
In China, a study of 44,672 confirmed cases until February 11, concluded that 1.2% or 889 were asymptomatic, or cases that have no symptoms. This makes containing this disease and slowing it down particularly challenging, say experts.
According to experts, understanding the incubation period is very important for health authorities as it allows them to introduce more effective quarantine systems for people suspected of carrying the virus, as a way of controlling and hopefully preventing the spread of the virus.
Reproductive number: One person can infect over 2
The reproductive number – the number of secondary infections generated from one infected individual – is understood to be between 2 and 2.5 for the COVID-19 virus, according to WHO experts. This implies that each infected person can transmit the virus to another two or over two people on an average at current transmission rates.
A study had said self-sustaining human-to-human transmission of the novel coronavirus is the only plausible explanation of the scale of the outbreak in Wuhan.
“We estimate that, on average, each case infected 2.6 (uncertainty range: 1.5-3.5) other people up to January 18, 2020, based on an analysis combining our past estimates of the size of the outbreak in Wuhan with computational modeling of potential epidemic trajectories. This implies that control measures need to block well over 60% of transmission to be effective in controlling the outbreak,” said the researchers.
Further, according to the WHO, the serial interval -- the time between successive cases -- is estimated to be 5-6 days For the influenza virus, the serial interval is three days. This means that influenza can spread faster than COVID19.
“Transmission in the first 3-5 days of illness, or potentially pre-symptomatic transmission – transmission of the virus before the appearance of symptoms – is a major driver of transmission for influenza. In contrast, while we are learning that there are people who can shed COVID-19 virus 24-48 hours prior to symptom onset, at present, this does not appear to be a major driver of transmission,” said the WHO.
89 million masks needed daily
Based on WHO modeling, an estimated 89 million medical masks are required for the COVID-19 response each month. For examination gloves, that figure goes up to 76 million, while international demand for goggles stands at 1.6 million per month.
Healthcare workers rely on personal protective equipment to protect themselves and their patients from being infected and infecting others. “We can’t stop COVID-19 without protecting health workers first,” said Dr Ghebreyesus.
But shortages are leaving doctors, nurses and other frontline workers dangerously ill-equipped to care for COVID-19 patients, due to limited access to supplies such as gloves, medical masks, respirators, goggles, face shields, gowns, and aprons.
According to the WHO, since the start of the COVID-19 outbreak, prices have surged. Surgical masks have seen a six-fold increase, N95 respirators have trebled and gowns have doubled.
To meet rising global demand, the WHO estimates that the industry must increase manufacturing by 40%.
As of March 3, WHO has shipped nearly half a million sets of personal protective equipment to 47 countries, but supplies are rapidly depleting, they add.