By Dr C Hemavathi
The Remdesivir drug is a widely discussed and debated subject in the context of COVID-19 which manifests with a wide clinical spectrum ranging from asymptomatic patients to septic shock and multiorgan dysfunction. The present health crisis is classified based on the severity of the presentation such as mild, moderate, severe and critical. The most common symptoms of patients include fever (98.6%), fatigue (69.6%), dry cough and diarrhea.
Patients with mild illness may present with symptoms of an upper respiratory tract viral infection which include dry cough, mild fever, nasal congestion, sore throat, headache, muscle pain and malaise. It is also characterised by the absence of serious symptoms such as dyspnoea. A majority (81%) of COVID-19 cases are mild in nature as per the existing state of affairs. Furthermore, radiograph features are also absent in such cases. Patients with mild disease can quickly deteriorate into severe or critical cases in the absence of timely, proper and adequate healthcare.
In case of moderate disease, the patients exhibit respiratory symptoms of cough, shortness of breath, and tachypnea. However, no signs and symptoms of severe disease are present.
Patients with severe disease exhibit severe pneumonia along with acute respiratory distress syndrome, sepsis, or septic shock. Appropriate clinical diagnosis and radiographic studies are necessary to avoid further complications.
The US Center for Disease Control and Prevention has developed certain criteria for persons under investigation. Immediate prevention and infection control measures are necessary in respect of persons under investigation. Epidemiological factors are used to assess the need for testing. These include close contact with a laboratory-confirmed patient within 14 days of symptoms or travel history to an infected area within 14 days of symptom onset. It is necessary to collect samples from both the upper and lower respiratory tracts according to the norms of the World Health Organisation. This can be achieved through expectorated sputum, bronchoalveolar lavage, or endotracheal aspirate. These samples are then assessed for viral ribonucleic acid using polymerase chain reaction. It is recommended to repeat the test for re-verification purposes if a positive test result is obtained. A negative test with a strong clinical suspicion also demands repeat testing.
Isolation remains the most effective measure for the containment of COVID-19. No specific anti-viral medication or vaccine is currently available. Therefore, the treatment of COVID-19 includes symptomatic care and oxygen therapy. Patients with mild infections require early supportive management with the use of acetaminophen, external cooling, oxygen therapy, nutritional supplements and anti-bacterial therapy. Critically ill patients require high flow oxygen, extracorporeal membrane oxygenation, glucocorticoid therapy and convalescent plasma. The administration of systemic corticosteroids is not recommended to treat Acute Respiratory Distress Syndrome. Moreover, unnecessary administration of antibiotics should also be avoided to prevent further complications.
ECMO should be considered in patients with refractory hypoxemia despite undergoing protective ventilation. Patients with respiratory problems require intubation, mechanical ventilation, high-flow nasal oxygen, or non-invasive ventilation. Treatment of septic shock requires hemodynamic support with the administration of vasopressors. Organ function support is necessary for patients with multiple organ dysfunctions.
Therapeutically, aerosol administration of alpha-interferon (5 million units twice daily), chloroquine phosphate, and lopinavir/ritonavir have been suggested. Other suggested anti-virals include ribavirin and abidor. The use of three or more anti-viral drugs simultaneously is not advisable. The present clinical studies suggest that Remdesivir can be used for prophylaxis and therapy. Furthermore, a fusion inhibitor targeting the HR1 domain of spike protein has the potential to treat COVID-19.
Preventive measures basically include optimising infection control protocols, self-isolation, and patient isolation during the provision of clinical care. Close contact with patients, farm animals and wild animals should be prevented. Patients and the general public must cover coughs and sneezes to prevent aerosol transmission. Frequent handwashing with soap and water and hand sanitizers is an effective preventive method. Immunocompromised individuals are advised to avoid public gatherings. Emergency medicine departments must apply strict hygiene measures for the control of infections. Healthcare personnel must use personal protective equipment such as N95 masks, FFP3 masks, gowns, eye protection, gloves and gowns.
The COVID-19 pandemic has caused more infections and deaths as compared with SARS or MERS. It is deemed that SARS-CoV-2 is more infectious than SARS or MERS. Elderly citizens with comorbidities are at great risk of fatality. The rapid spread of disease warrants intense surveillance and isolation protocols to prevent further transmission. No authentic medication or vaccine is found to date. Current treatment strategies primarily deal with symptomatic care and oxygen therapy. Prophylactic vaccination is required for the future prevention of COV-related epidemics or pandemics.
Remdesivir is found to be practically useful in the treatment of coronavirus and the prevention of deaths among patients. It is evident from the medical observation that the drug substantially reduces the length of hospitalisation of the affected persons. The drug was given on the basis of emergency authorisation in the US by the Food and Drug Administration on May 1, 2020. It is also noted that the drug modestly reduces the recovery time in the case of severely ill patients. The utility of the drug is not well established in respect of the prevention of death. The Remdesivir, hydroxychloroquine, lopinavir/ritonavir and interferon regimens have little or no effect on 28-day mortality or the in-hospital course according to the observation of scientists. However, it is widely believed that early treatment with the experimental antiviral drug Remdesivir significantly reduced clinical disease and damage to the lungs of rhesus macaques infected with SARS-CoV-2.
(The writer is Associate Professor and Head, Government Women’s Science College, Vijayanagar 4th Stage, Mysuru).