SARS-CoV-2

 

Currently, our knowledge about the animal origin of SARS-CoV-2 remains largely incomplete. The reservoir hosts of the virus have not been clearly proven. It is not known whether SARS-CoV-2 has been transmitted to humans via an intermediate host and which animals may act as intermediate hosts. Detection of RaTG13, RmYN02 and pangolin coronaviruses implies that several coronaviruses similar to SARS-CoV-2 are circulating in wildlife. Moreover, since previous studies showed recombination as the possible origin of some sarbecoviruses such as SARS-COV, it cannot be ruled out that viral RNA recombination between several related coronaviruses was involved in the evolution of SARS-CoV-2. Expanded surveillance of SARS-CoV-2-related viruses inChina, Southeast Asia and other regions targeting bats, wild and captive pangolins and other animal species will help us better understand the zoonotic origins of SARS-CoV-2.

In addition to wildlife, researchers examined the susceptibility of domesticated and laboratory animals to SARS-COV-2 infection. The study showed experimentally that SARS-CoV-2 multiplies efficiently in cats and in the upper respiratory tract of ferrets, while dogs, pigs, chickens and ducks were not susceptible to SARS-COV-2 (REF.43). Mink susceptibility was documented by a report from the Netherlands on an outbreak of SARS-CoV-2 infection in farmed minks. While symptoms were mild in most infected minks, some developed severe respiratory distress and died of interstitial pneumonia1/44. Both virological and serological testing found evidence of natural SARS-COV-2 infection in two dogs from households with human cases of COVID-19 in Hong Kong, but the dogs

Angiotensin-converting enzyme 2

Appeared asymptomatic. Another serological study detected SARS-CoV-2 neutralizing antibodies in cat serum samples collected in Wuhan after the outbreak of COVID-19, providing evidence for SARS-CoV-2 infection in cat populations in Wuhan, although the possibility of transmission of SARS-CoV-2 from cats to humans is currently uncertain46.

Receptor usage and pathogenesis

SARS-CoV-2 uses the same receptor as SARS-CoV, angiotensin-converting enzyme 2 (ACE2) 11,47. In addition to human ACE2 (hACE2), SARS-CoV-2 also recognizes ACE2 from pig, ferret, rhesus monkey, nutmeg, cat, pangolin, rabbit and dog11,43,48,49. The widespread receptor usage of SARS-CoV-2 suggests that it may have a wide host range, and the varying efficiency of ACE2 usage in different animals may indicate their different susceptibility to SARS-CoV-2 infection. The S1 subunit of a coronavirus is further divided into two functional regions, an N-terminal domain and a C-terminal domain. Structural and biochemical analyzes identified a region of 211 amino acids (amino acids 319–529) in the C-terminal S1 region of SARS-CoV-2 as the RBD, which has a key role in virus entry and is the target of neutralizing antibodies 50,51 ( FIG. 3a). The RBM mediates contact with the ACE2 receptor (amino acids 437-507 of the SARS-CoV-2 S protein), and this region in SARS-CoV-2 differs from that of SARS-CoV in the five residues critical to

 

Evaluated intrauterine vertical transmission of COVID-19 infection in nine infants born in

infected mothers, they found that none of the

infants tested positive for the virus.45 Likewise, there was no evidence of intrauterine infection

caused by vertical transmission in the SARS and MERS epidemics.4 43

The CDC maintains that infants born to mothers with confirmed COVID-19 are considered persons under investigation (PUI) and should be temporarily separated from the mother and isolated.46

 Breastfeeding and infant care

The data available to date are limited and cannot confirm whether or not COVID-19 can be transmitted through breast milk.40 Evaluation of the presence of COVID-19 in breast milk samples from six patients showed a negative result.45 The CDC points out that in the case of confirmed or suspected COVID-19 infection, the decision about whether or how to initiate or continue breastfeeding should be made by the mother in collaboration with family and health professionals.47 Careful precautions should be taken by the mother to prevent transmission of the disease to her infant through respiratory droplets during breastfeeding. This includes wearing a face mask and hand practice FOR good Heart.