The document summarizes COVID-19, caused by SARS-CoV-2. It describes the origin in Wuhan, China in late 2019. Transmission occurs through respiratory droplets from coughing or sneezing. Symptoms range from mild to severe respiratory illness and death. Diagnosis is via PCR testing of nasal swabs. The virus utilizes the ACE2 receptor for cell entry and may cause a cytokine storm. Management involves social distancing, hand washing, testing/isolation of cases and supportive care, as no vaccine yet exists. Experimental treatments under investigation target the virus itself or hyper-inflammation.

1. Corona Virus Disease 2019
(COVID-19)
THE STORY OF OUTBREAK
BY AMIR S. ISMAIL
PERIODONTIST &
ORAL HYGIENIST
KAFR SAQR CENTRAL
HOSPITAL
EGYPT

2. Introduction
COVID-19 is a highly infectious disease caused by
Sever Acute Respiratory Syndrome Corona virus 2
(SARS-COV 2) a beta coronavirus that shares genetic
sequence with SARS-COV 2002 in China (70%
similarity) and MERS-COV 2012 (40% similarity).
Corona viruses infecting mammals and birds so the virus
is thought to be natural and have an animal origin,
through spillover infection.

3. Origen First identified in December 2019 in seafood and wet animal market in Wuhan,
China.
 From December 18, 2019 through December 29, 2019, five patients were
hospitalized with acute respiratory distress syndrome and one of these patients
died.
 By January 2, 2020, 41 admitted hospital patients had been identified as having
laboratory-confirmed COVID-19 infection.
 These patients were presumed to be infected in that hospital, likely due to
nosocomial infection rather than it was an outbreak.

4. Structure

5. Transmission
 The virus is typically spread during close contact and via respiratory droplets
produced when people cough or sneeze.
 Respiratory droplets may be produced during breathing but it is not considered
airborne.
 It may also spread when one touches a contaminated surface and then their face.
 It is most contagious when people are symptomatic, although spread may be
possible before symptoms appear.

6. The virus can live on surfaces up to 72 hours.
The virus remained viable in aerosols three hours.
The virus has been found in the feces of 53% of hospitalized
people and more anal swab positives have been found than oral
swab positives in the later stages of infection.

7. Diagnosis
 Chinese scientists were able to isolate a strain of the coronavirus and
publish the genetic sequence so that laboratories across the world could
independently develop polymerase chain reaction (PCR).
 The standard method of diagnosis is by reverse transcription polymerase
chain reaction (rRT-PCR) from a nasopharyngeal swab in addition of
symptoms, risk factors and a chest CT scan showing features of pneumonia
(ground glass opacities).

8. Pathogenesis

9.  The virus accesses host cells via the enzyme ACE2, which is most
abundant in pulmonary alveoli type II and the glandular cells of gastric,
duodenal and rectal epithelium as well as endothelial cells and
enterocytes of the small intestine.
 The virus uses a special surface glycoprotein called a "spike"
(peplomer) to connect to ACE2 activated by Transmembrane protease
serine 2 (TMPRSS2)to enter the host cell.

12.  The density of ACE2 in each tissue correlates with the severity of the
disease in that tissue and some have suggested that decreasing ACE2
activity might be protective, though another view is that decreasing
ACE2 using angiotensin II receptor blocker medications could be
protective and that these hypotheses need to be tested.
Patients infected with COVID-19 may show higher leukocyte
numbers, and increased levels of plasma pro-inflammatory
cytokines IL1, IL6, TNFα, IFNγ (Cytokine storm).

13. Immunopathology
 A cytokine release syndrome (CRS) of IL-2, IL-7, IL-6, granulocyte-
macrophage colony-stimulating factor (GM-CSF), interferon-γ
inducible protein 10 (IP-10), monocyte chemoattractant protein 1
(MCP-1), macrophage inflammatory protein 1-α (MIP-1α), and tumor
necrosis factor-α (TNF-α) indicate an underlying immunopathology.

14. As a response to cytokine storm Acute respiratory distress
syndrome (ARDS) may develop in severe cases, which may
progress to Acute Disseminated intravascular Coagulation
(DIC) and Multiorgan Dysfunction syndrome (MODS).
Histones (H3&H4) and High mobility group box 1 (HMGB1)
play a crucial role in ARDS and DIC leading to MODS.

15. Signs and symptoms
 Infection with the virus may be asymptomatic or develop a flu-like
symptoms, including hi fever, cough, fatigue, and shortness of breath.
 Time from exposure to onset of symptoms is generally between two
and fourteen days, with an average of five days.
 In sever cases difficulty breathing, persistent chest pain, myalgia,
difficulty waking, and bluish face or lips.

17.  Less commonly, upper respiratory symptoms, such as sneezing, runny
nose, or sore throat may be seen. (difference between (SARS-COV2)
and (SARS-COV and MERS).
 Symptoms such as nausea, vomiting, diarrhea, loss of the sense of
smell and distortion of the sense of taste.
 The disease may progress to pneumonia, multi-organ failure, and
death, time from symptom onset to needing mechanical ventilation is
typically 8 days.

18. Management of the pandemic
 Because a vaccine against SARS-CoV-2 is not expected to become available until
2021 at the earliest, a key part of managing the COVID-19 pandemic is trying to
decrease the epidemic peak, known as flattening the epidemic curve through
various measures seeking to reduce the rate of new infections.
 Preventive measures to reduce the chances of infection include staying at home,
avoiding crowded places, washing hands with soap and warm water often and for
at least 20 seconds, practicing good respiratory hygiene and avoiding touching
the eyes, nose, or mouth with unwashed hands.

19.  The CDC recommends covering the mouth and nose with a tissue when coughing
or sneezing and recommends using the inside of the elbow if no tissue is
available.
 They also recommend proper hand hygiene after any cough or sneeze.
 Social distancing strategies aim to reduce contact of infected persons with large
groups by closing schools and workplaces, restricting travel, and canceling mass
gatherings.
 Social distancing also includes that people stay at least 6 feet apart (about 1.80
meters).

20.  According to the WHO, the use of masks is recommended only if a person is coughing
or sneezing or when one is taking care of someone with a suspected infection.
 Some countries also recommend healthy individuals to wear face masks, particularly
China, Hong Kong and Thailand. That may prevent touching face.
 Those diagnosed with COVID-19 or who believe they may be infected are advised by
the CDC to stay home except to get medical care, call ahead before visiting a healthcare
provider, wear a face mask before entering the healthcare provider's office and when in
any room or vehicle with another person, cover coughs and sneezes with a tissue,
regularly wash hands with soap and water, and avoid sharing personal household items.

21.  CDC recommends using an alcohol-based hand sanitizer with at least
60% alcohol, but only when soap and water are not readily available.
 Prevention efforts are multiplicative, with effects far beyond that of a
single spread.
 Each avoided case leads to more avoided cases down the line, which in
turn can stop the outbreak in its tracks.

22. Treatment
 Only symptomatic supportive care is the only treatment modality accepted by WHO,
which may include increase fluid intake for hydration , antipyretic for high fever,
oxygen support, and supporting other affected vital organs.
 Extracorporeal membrane oxygenation (ECMO) has been used to address the issue
of respiratory failure, but its benefits are still under consideration.
 While the WHO does not oppose the use of non-steroidal anti-inflammatory drugs
such as ibuprofen for symptoms, some recommend paracetamol (acetaminophen) for
first-line use.

23. Personal protective equipment
 Precautions must be taken to minimize the risk of virus transmission, especially
in healthcare settings when performing procedures that can generate aerosols,
such as Dentists, intubation or hand ventilation.
 CDC outlines the specific guidelines for the use of personal protective equipment
(PPE) during the pandemic. The recommended gear includes:
 • respirator or facemask. • gown.
 • medical gloves. • eye protection.

24. Experimental treatment
 Some of trials medications:
 1. Passive immunization by injecting IgG from healed patient into a diseased one.
 2. Chloroquine and Hydroxychloroquine the antimalarial drugs have therapeutic
effects were observed in aspects of fever reduction, improvements on CT imaging
and retarded disease progression though 2 characteristics (anti viral and
immunomodulation) and 3 steps (pre-infection, after viral entry and during
cytokine storm release).

25.  3. Studies have demonstrated that initial spike protein priming by transmembrane
protease serine 2 (TMPRSS2) is essential for entry of SARS-CoV-2 via
interaction with the ACE2 receptor. These findings suggest that the TMPRSS2
inhibitor camostat approved for use in Japan for inhibiting fibrosis in liver and
kidney disease might constitute an effective off-label treatment.
 4. broad-spectrum antiviral drugs like Nucleoside analogues; Remdesivir (GS-
5734), an experimental drug being developed for the treatment of Ebola virus
infection.
 5. protease inhibitors (neuraminidase inhibitors) like Oseltamivir, lopinavir and
ritonavir.

26. Recently
 Controlling of DIC to prevent MODS by some ways;
 Heparinization of patients.
 Compstatin, a potent C3 convertase inhibitor.
 A recombinant Activator Protein C (APC) able to degrade histones both in vitro and
in vivo thus lowering the histone toxicity towards Endothelial cells in vitro and
preventing lethality in histone-treated animals.

27. Thank youREFERENCE; WIKIPEDIA AND WHO