COVID-19( SARS-COV-2)

• Classification
• Virology
• Pathogenesis
• Clinical manifestations/symptoms
• Diagnosis
• Treatment
• Conclusion
• Preventive Measures

CLASSIFICATION

Novel beta coronavirus of the same subgenus as SARS-COV(Severe acute respiratory syndrome-corona virus) named SARS-COV-2.Coronavirus disease 2019(COVID-19) has rapidly disseminated worldwide hence declared by World Health Organization as Pandemic

VIROLOGY: Class of virus
An enveloped virus with a positive-sense single-stranded RNA(Ribonucleic acid) genome.

PATHOGENESIS: How the disease starts

Coronavirus S protein has been reported as a significant determinant of virus entry into host cells. The envelope spike glycoprotein binds to its cellular receptor, ACE 2() for SARS-COV. The entry of SARS-COV into the cell was initially identified to be accomplished by direct membrane fusion between the virus and plasma membrane. It is found that a critical proteolytic cleavage event occurred at SARS-COV S-protein at position S2 mediated the membrane fusion and viral infectivity.
After the virus enters the cell, the viral RNA genome is released into the cytoplasm and translated into two polyproteins and structural proteins, after which the viral genome begins to replicate. The newly formed envelope glycoproteins are inserted into the membrane of the endoplasmic reticulum or Golgi and the nucleocapsid is formed by the combination of genome RNA and nucleocapsid protein.

Antigen Presentation In Corona Virus Infection

While the virus enters the cells its antigen will be presented to the antigen presentation cells (APC) which are a central part of the body’s anti-viral immunity. Antigenic peptides are presented by major histocompatibility complex(MHC), or human leukocyte antigen(HLA) in humans and then recognized by virus-specific cytotoxic T lymphocytes (CTLS). For SARS-COV and MERS-COV the presentation is mainly dependent on MHC-1 molecules, but MHC-II also contributes to its presentation.

Humoral and Cellular Immunity

Antigen presentation subsequently stimulates the body’s humoral and cellular Immunity which are mediated by virus-specific B and T cells similar to acute viral infection the antibody profile against the SARS-COV virus has a typical pattern of IgM and IgG(immunoglobulin M & G) production. IgM disappears over 12weeks, IgG plays a protective role.
Comparing to humoral responses, there are more researches on the cellular Immunity of coronavirus. The latest report shows the number of CD4+ and CD8+ T cells in the peripheral blood of SARS-COV-2 infected patients significantly is reduced were as evidenced by high proportions of HLA-DR(CD4 3.47%) and CD38(CD8 39.4%) double positive. Even if there is no antigen, CD4+ and CD8+ memory T cells can persist for four years in the part of SARS-COV recovered individuals and can perform T cell proliferation, DTH response and production of IFN-8(inferno-8), six years after SARS-COV infection specific T cell memory responses to the SARS-COV peptide library could still be identified in 14 of 23 recovered SARS patients.

Cytokine storm in COVID-19

The report in Lancet shows ARDS( Acute respiratory distress syndrome) is the main cause of death of COVID-19 . of the 41 SARS-COV-2 infected patients admitted in the early stages of the outbreak, six died from ARDS.
ARDS is the common immuno-pathophysiological event for SARS-COV-2, SARS-COV and MERS-COV Infection.
One of the main mechanism of ARDS is the cytokine storm, the deadly uncontrolled systemic inflammatory response resulting from the release of a large amount of pro-inflammatory cytokines(INF-alpha, INF-gamma, IL-B, IL-6, IL-12, IL-18, IL-33, TNF-alpha, TGF-B, etc),(IL(interleukin), TNF(Tumor necrotic factor) and Chemokines (CCL2, CCL3, CCL5, CXCL8, CXCL9, CXCL10, etc.)
The cytokine storm will trigger a violent attack by the immune system to the body, cause ARDS and multiple organ failure and finally lead to death in severe cases of SARS-COV-2 infection, just like what occurs in SARS-COV and MERS-COV Infection

CLINICAL MANIFESTATION/ SYMPTOMS

Clinical manifestations range from mild respiratory symptoms to severe pneumonia and a fatality rate around 2% person to person transmission is occurring both in the community and health care settings.
Clinical symptoms of COVID-19 are highly atypical, including;
Respiratory symptoms, like ARDS
Non-productive cough
Fever
Dyspnea
Viral pneumonia
Loss of taste

Diagnosis of COVID-19

Clinical diagnosis of COVID-19 is mainly based on
1.epidemiological history
2.clinical manifestation
3.some auxiliary examinations such as :
4.Nucleic acid detection
5.CT scan
6.Immune identification technology (point of care testing (POCT)) of IgM & IgG
7.Enzyme-linked immunosorbent assay(ELISA)
8.Blood culture

Nucleic Acid Detection Technology

The two commonly used nucleic acid detection technologies for SARS-COV -2 are real-time quantitative polymerase chain reaction (RT-qPCR) and high. Throughput sequencing. The authoritative identification method for SARS- COV -2 is virus blood culture and high- throughput sequencing of the whole genome, However, the later is limitedly used due to high cost.

TREATMENT OF COVID-19

Virally targeted inhibitors like Remdesivir and adenosine analogs that can target the RNA- dependent RNA polymerase and block viral RNA synthesis has been a promising antiviral drug against a wide array of RNA viruses (including SARS & MERS-COV) Infection in culture cells
Remdesivir and Chloroquine have been demonstrated to inhibit SARS-COV-2 effectively in vitro. Hence other nucleoside analogs such as Favipiravir, Ribavirin, and Galidesivir, may be potentially clinically applicable against SARS-COV-2. Other monoclonal antibodies neutralizing SARS-COV, such as M396 CR 3014, could be an alternative for the treatment of SARS-COV-2

VACCINE

Effective SARS-COV-2 vaccines are essential for reducing disease severity, viral shedding and transmission thus helping to control coronavirus outbreak. The WHO is working with the Chinese scientists as well as other scientists around the world to launch more than 80 clinical trials on a potential treatment for SARS-COV-2. Traditional Chinese medicine seems to have some effects on the supportive treatments.

CONCLUSION

The occurrence and development of SARS-COV-2 depend on the interaction between the virus and the individuals’ immune system-viral load, viral titer, and viability of the virus in vitro. The individuals’ immune system factors include genetics (such as HLA genes ), age, gender nutritional status,neuroendocrine-immune regulation, and physical status. These factors all contribute to whether an individual is infected with the virus, the duration and severity of the disease and the reinfection. In the early stages of the pandemic, accurate diagnosis helps control the spread of the disease. It is imperative to develop new safe, accurate, fast and simple new technologies for detecting SARS-COV-2. Of course, physicians will intentionally intervene in the two factors to make them develop into a directional beneficial to human health, which can help patients recover as soon as possible. However, it must not be considered that medical intervention can achieve a 100% curative effect.

KEY COVID-19 PREVENTIVE MEASURES

Key preventive measures remain;
1.Personal hygiene including regular hand washing with an alcohol-based sanitizers
2.Social distancing, not less than a meter especially to people with one or more of the symptoms
3.Regular home exercises, like rope skipping and short distance running as well as taking a deep breath followed by a gentle release
4.Proper cleaning of our environment
Isolating yourself followed by a call for immediate medical attention when one or more symptoms of COVID -19 develops

STAY SAFE
STAY HOME

Huawei’s P Smart line already has its 2020 member planned. The phone has recently been certified with 3 cameras by TENAA and now some renders have come up which show us the possible look of the phone. Images also include the MatePad Pro tablet.

Regarding the design, it seems that P Smart 2020 will not present anything new. We still have the droplet notch, a glossy back cover, and the triple chamber configuration. Specifications will be a slight upgrade from 2019.

• Kirin 810 Processor
• 4 GB RAM
• 128 GB internal storage
• 48 MP + 8 MP + 2 MP Main Camera
• 16MP front camera
• 3,900 mAh battery

In addition to memory upgrades, P Smart is expected to bring improved cameras and the inclusion of an ultra-wide lens finally. If Huawei wants to avenge this mobile phone in the Portuguese market, it will have to compete with Samsung’s A line, which features very interesting equipment.

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MatePad Pro is a pseudo rival to the iPad

The MatePad Pro, also known as MediaPad M7, will be the brand’s next tablet. The tablet has varied colors, bringing some variety to the tablet market, which usually features equipment in black, blue and silver.

We also have a rear dual camera and a “hole” design on the screen, where is the front camera. The tablet comes with a USB-C port, biometric reader under the glass and a pen holder and keyboard case.

However, this tablet will have the same problem as the rest of the market: the operating system. Although versatile Android is a limited system when it comes to productivity. The same cannot be said of the iPad which with the new iOS 13 represents a true piece of work technology.

As long as Android stays as it is, tablets will remain big phones. Huawei does not seem to include major applications or operating system changes to make its tablets more attractive, as Samsung, for example.