Science and the Coronavirus: Experimental drugs, genome analysis, portable tests, and the role of cruise ships in spreading the virus
From time to time, we'll be bringing you a roundup of the latest coronavirus news as pertains to science, medical treatments, medical trials, and studies from the scientific community. Here's the second edition.
Experimental drugs to treat COVID-19?
The world desperately needs new medicines to treat COVID-19, the disease caused by the novel coronavirus that has pretty much shut down most of the world. Unfortunately, the process to develop new medicines can take a decade or more, and more often than not, experimental medicines fail.
But drug companies and medical researchers the world over are working day and night to develop and deliver new medicines. Several dozen are now in development, and you can see highlights of those efforts here. So far, studies are small and lack real control groups, which make it hard for researchers to be sure of their conclusions.
Doctors on the front lines have been trying older medicines, such as the malaria drugs hydroxychloroquine and chloroquine, in the hopes that they will prove effective. Large studies of such medicines are already in process.
People are holding on to hope that something will be available soon to help us fight this virus, known as SARS-CoV-2. Click here to have a look at what’s being developed and how soon it could be ready. It is important to keep two things in mind: 1) Supply could be an issue if large numbers of people need it. 2) Some of these timelines could shift, and some of these treatments and vaccines are likely to fail. That is the unfortunate reality of how medicine works.
Genome Analysis suggests that Coronavirus could be a 'Chimera' of two different viruses
There are many grey areas as to the origins of SARS-CoV-2, the virus that causes COVID-19. There are doubts as to whether it originated in a bat or a pangolin, or some other wild animal. And where did it originate? Did it really originate in a wet market in Wuhan? Or was its origin in the depths of a forest or a cave?
In December 2019, 27 of the first 41 people hospitalised (66 per cent) frequented a wet market located in the heart of Wuhan city in Hubei province. But, according to a study conducted at Wuhan Hospital, the very first human case - patient zero - did not frequent this market.
Instead, a molecular dating estimate based on the SARS-CoV-2 genomic sequences indicates an origin in November. This raises questions about the link between this COVID-19 epidemic and wildlife.
The role of cruise ships in the transmission of COVID-19
Cruise ships are often settings for outbreaks of infectious diseases because of their closed environment and contact between travellers from many countries.
More than 800 cases of laboratory-confirmed COVID-19 cases occurred during outbreaks on three cruise ship voyages, and cases linked to several additional cruises have been reported across the United States. Transmission occurred across multiple voyages from ship to ship by crew members; both crew members and passengers were affected; 10 deaths associated with cruise ships have been reported to date.
Cruise ships bring diverse populations together under confined circumstances for a period of several weeks. These are ideal circumstances for respiratory illnesses to take hold and spread amongst the passengers. Passengers on certain cruise ship voyages might be aged 65 years and above, which places them at greater risk for severe consequences of SARS-CoV-2 infection. In this paper we can see that transmission occurred across multiple voyages of several ships.
During February 7–23, 2020, the largest cluster of COVID-19 cases outside mainland China occurred on the Diamond Princess cruise ship, which was quarantined in the port of Yokohama, Japan, on February 3. On March 6, cases of COVID-19 were identified in persons on the Grand Princess cruise ship off the coast of California, which was subsequently quarantined. By March 17, confirmed cases of COVID-19 had been associated with at least 25 additional cruise ship voyages.
On February 21, the CDC recommended avoiding travel on cruise ships in Southeast Asia; on March 8, this recommendation was broadened to include deferring all cruise ship travel worldwide for those with underlying health conditions and for persons aged 65 years and above. On March 13, the Cruise Lines International Association announced a 30-day voluntary suspension of cruise operations in the United States. The CDC issued a level 3 travel warning on March 17, recommending that all cruise travel be deferred worldwide.
Introduction of fast portable tests to curb the coronavirus pandemic
Singapore, Taiwan, and Hong Kong have had extraordinary success in limiting the impact of the sudden acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This shows that an investment in pandemic preparedness yields direct results. Despite their close proximity to China, these three countries have managed to keep their case numbers and their fatalities low.
The rest of the world, however, is completely unprepared for the onslaught of the virus, and it shows. Many healthcare systems have had to face community transmission before adequate testing was in place for isolation and tracking. Although public health authorites in many places imposed draconian measures and isolation tactics, many were caught on the backfoot in validating, implementing, and distributing SARS-CoV-2 diagnostic tests and in establishing decentralized point-of-care (POC) testing.
That situation is now starting to change. More and more of these tests are being shipped to the places that need them. Besides, the present crisis could be a defining moment for diagnostics based on CRISPR technology, with the first diagnostic test based on CRISPR gene editing technology only be weeks away. To stop the virus spreading, however, will take a massive effort to scale up the production of easy-to-use POC tests and then to deploy them widely.
Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents
Currently, the emergence of a novel human coronavirus, SARS-CoV-2, has become a global health concern causing severe respiratory tract infections in humans. Human-to-human transmissions have been described with incubation times between 2-10 days, facilitating its spread via droplets, contaminated hands or surfaces.
This study reviewed the literature on all available information about the persistence of human and veterinary coronaviruses on inanimate surfaces as well as inactivation strategies with biocidal agents used for chemical disinfection, e.g. in healthcare facilities. The analysis of 22 studies reveals that human coronaviruses such as Severe Acute Respiratory Syndrome (SARS) coronavirus, Middle East Respiratory Syndrome (MERS) coronavirus or endemic human coronaviruses (HCoV) can persist on inanimate surfaces like metal, glass or plastic for up to 9 days, but can be efficiently inactivated by surface disinfection procedures with 62–71% ethanol, 0.5% hydrogen peroxide or 0.1% sodium hypochlorite within 1 minute.
Other biocidal agents such as 0.05–0.2% benzalkonium chloride or 0.02% chlorhexidine digluconate are less effective. As no specific therapies are (yet) available for SARS-CoV-2, early containment and prevention of further spread will be crucial to stop the ongoing outbreak and to control this novel infectious thread.