Kuiz: 31-33

Acute Paediatric Hepatitis of Unknown Origin UK: Working hypotheses

The following hypotheses are all being actively tested by the investigations in process.

There are increased paediatric acute non-A-E hepatitis presentations due to:

1. A normal adenovirus infection, due to one of:

a. Abnormal susceptibility or host response which allows adenovirus infection to progress more frequently to hepatitis (whether direct or immunopathological), for example from lack of exposure during the coronavirus (COVID-19) pandemic.

b. An exceptionally large wave of normal adenovirus infections, causing a very rare or under-recognised complication to present more frequently.

c. Abnormal susceptibility or host response to adenovirus due to priming by a prior infection with SARS-CoV-2 (including Omicron restricted) or another infection.

d. Abnormal susceptibility or host response to adenovirus due to a coinfection with SARS-CoV-2 or another infection.

e. Abnormal susceptibility or host response to adenovirus due to a toxin, drug or environmental exposure.

2. A novel variant adenovirus, with or without a contribution from a cofactor as listed above.

3. A post-infectious SARS-CoV-2 syndrome (including an Omicron restricted effect).

4. A drug, toxin or environmental exposure.

5. A novel pathogen either acting alone or as a coinfection.

The California and San Francisco Departments of Public Health have confirmed that a recent case of COVID-19 among an individual in California was caused by the Omicron variant (B.1.1.529). The individual was a traveler who returned from South Africa on November 22, 2021. The individual had mild symptoms that are improving, is self-quarantining and has been since testing positive. All close contacts have been contacted and have tested negative.

Genomic sequencing was conducted at the University of California, San Francisco and the sequence was confirmed at CDC as being consistent with the Omicron variant. This will be the first confirmed case of COVID-19 caused by the Omicron variant detected in the United States

On November 26, 2021, the World Health Organization (WHO) classified a new variant, B.1.1.529, as a Variant of Concern and named it Omicron and on November 30, 2021, the United States also classified it as a Variant of Concern. CDC has been actively monitoring and preparing for this variant, and we will continue to work diligently with other U.S. and global public health and industry partners to learn more. Despite the detection of Omicron, Delta remains the predominant strain in the United States

The recent emergence of the Omicron variant (B.1.1.529) further emphasizes the importance of vaccination, boosters, and general prevention strategies needed to protect against COVID-19. Everyone 5 and older should get vaccinated and boosters are recommended for everyone 18 years and older

KENILWORTH, N.J., Feb. 4, 2021 – Merck (NYSE: MRK), known as MSD outside the United States and Canada, today affirmed its position regarding use of ivermectin during the COVID-19 pandemic. Company scientists continue to carefully examine the findings of all available and emerging studies of ivermectin for the treatment of COVID-19 for evidence of efficacy and safety. It is important to note that, to-date, our analysis has identified:

- No scientific basis for a potential therapeutic effect against COVID-19 from pre-clinical studies;
- No meaningful evidence for clinical activity or clinical efficacy in patients with COVID-19 disease, and;
- A concerning lack of safety data in the majority of studies.

We do not believe that the data available support the safety and efficacy of ivermectin beyond the doses and populations indicated in the regulatory agency-approved prescribing information.

Malaysia received a second batch of COVID-19 vaccines on 21 May 2021, shipped via the COVAX Facility, a partnership between WHO, the Coalition for Epidemic Preparedness Innovations (CEPI), Gavi, and UNICEF. This is another important step in the fight against the COVID-19 pandemic and supporting immunization efforts by the Government of Malaysia.

The Government of Malaysia through the Ministry of Health and Ministry of Science, Technology and Innovation has been working together with WHO and UNICEF to bring life-saving vaccines to Malaysia.

The 559 200 doses of Oxford/AstraZeneca vaccines that arrived follow the 21 April COVAX shipment of 268 800 doses to Kuala Lumpur, Malaysia.

In total, Malaysia has received 828 000 doses of the expected 1 387 200 doses of Oxford/AstraZeneca vaccine provided by the COVAX Facility.

Bloomberg spoke to two experts about the vaccines, zeroing in on the Sinovac Biotech Ltd. shot, which has been the focus of a crisis in confidence after it posted efficacy levels of just above 50% in a final stage trial in Brazil -- the minimum required by leading global drug regulators.

According to Fiona Russell from the Murdoch Children’s Research Institute in Melbourne and Paul Griffin, a professor from the University of Queensland in Brisbane:

1. For very mild disease, requiring no treatment the efficacy of Sinovac is about 50%.
2. For infections requiring some medical intervention, it’s about 84%.
3. For moderate-to-severe Covid cases, it’s 100%!

Conclusion: That’s what you expect from Covid vaccines -- higher efficacy against more severe infections and lower against milder ones. From what I can see, it looks like a very worthwhile vaccine.

Airborne transmission of SARS-CoV-2 can occur during medical procedures that generate aerosols (“aerosol generating procedures”). WHO, together with the scientific community, has been actively discussing and evaluating whether SARS-CoV-2 may also spread through aerosols in the absence of aerosol generating procedures, particularly in indoor settings with poor ventilation.

Thus, a susceptible person could inhale aerosols, and could become infected if the aerosols contain the virus in sufficient quantity to cause infection within the recipient. However, the proportion of exhaled droplet nuclei or of respiratory droplets that evaporate to generate aerosols, and the infectious dose of viable SARS-CoV-2 required to cause infection in another person are not known, but it has been studied for other respiratory viruses.

To date, transmission of SARS-CoV-2 by this type of aerosol route has not been demonstrated; much more research is needed given the possible implications of such route of transmission.

Recent clinical reports of health workers exposed to COVID-19 index cases, not in the presence of aerosol-generating procedures, found no nosocomial transmission when contact and droplet precautions were appropriately used, including the wearing of medical masks as a component of the personal protective equipment (PPE). These observations suggest that aerosol transmission did not occur in this context.

Further studies are needed to determine whether it is possible to detect viable SARS-CoV-2 in air samples from settings where no procedures that generate aerosols are performed and what role aerosols might play in transmission.

Outside of medical facilities, some outbreak reports related to indoor crowded spaces have suggested the possibility of aerosol transmission, combined with droplet transmission, for example, during choir practice, in restaurants or in fitness classes. In these events, short-range aerosol transmission, particularly in specific indoor locations, such as crowded and inadequately ventilated spaces over a prolonged period of time with infected persons cannot be ruled out.

However, the detailed investigations of these clusters suggest that droplet and fomite transmission could also explain human-to-human transmission within these clusters. Further, the close contact environments of these clusters may have facilitated transmission from a small number of cases to many other people (e.g., superspreading event), especially if hand hygiene was not performed and masks were not used when physical distancing was not maintained.

COVID-19 spreads mainly from person to person through respiratory droplets produced when an infected person coughs, sneezes, talks, or raises their voice (e.g., while shouting, chanting, or singing). These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs.

Recent studies show that a significant portion of individuals with COVID-19 lack symptoms (are “asymptomatic”) and that even those who eventually develop symptoms (are “pre-symptomatic”) can transmit the virus to others before showing symptoms.

To reduce the spread of COVID-19, CDC recommends that people wear cloth face coverings in public settings when around people outside of their household, especially when other social distancing measures are difficult to maintain.

Why it is important to wear a cloth face covering

Cloth face coverings may help prevent people who have COVID-19 from spreading the virus to others. Wearing a cloth face covering will help protect people around you, including those at higher risk of severe illness from COVID-19 and workers who frequently come into close contact with other people (e.g., in stores and restaurants).

Cloth face coverings are most likely to reduce the spread of COVID-19 when they are widely used by people in public settings. The spread of COVID-19 can be reduced when cloth face coverings are used along with other preventive measures, including social distancing, frequent handwashing, and cleaning and disinfecting frequently touched surfaces.