Severe acute respiratory syndrome is new challenge for medical professionals

Epidemiology:
The disease is caused by RNA containing virus. This is a new virus and there is no antiviral drug available till today to destroy it. On the other hand, the Center for Disease Control (CDC) has announced that they have sequenced SARS virus. Now with this information scientists have begun to target antiviral drugs and vaccines. The sample was taken from SARS infected patient and it was grown in green monkeys kidney cell in order to grow RNA (ribonucleic acid).

The new sequence has 29,727 nucleotides, which places it well within the typical RNA boundaries for Corona virus. Members of this viral family tend to have between 29,000 and 31,000 nucleotides.

Symptoms of SARS:
The illness begins generally with advance fever 100.4°F and up, the equivalent to 38.0°C. Fever often is high, sometimes is associated with chills and rigors. Symptoms like headache, malaise, and muscle weakness are also included. Some patients have reported diarrhea during the fever period.

At the onset of illness, some people have mild respiratory symptoms. After 3 to7 days, a lower respiratory phase begins with the onset of a dry, nonproductive cough or dyspnea (shortness of breath). In 10% to 20% of the cases, the respiratory illness is severe enough to require intubation and mechanical ventilation. Typically, rash and neurological or gastrointestinal findings are absent.

Incubation period:
The incubation period of the SARS virus is typically 2 to 7 days and it can be up to 10 days. Case fatality as per World Health Organization (WHO) is 3%-10%.

Diagnostic Tests:
To diagnose SARS in its early stages, SARS associated Corona Virus (SARS-CoV) detection is essential.

Chest radiographs might be normal during the febrile prodrome (beginning of fever) and throughout the course of illness. However, in a substantial proportion of patients, the respiratory phase is characterized by early focal interstitial infiltrates. Some chest radiographs from patients in the late stages of SARS also have shown areas of consolidation.

Early in the course of disease, the absolute lymphocyte count is often decreased. Overall white blood cell counts have generally been normal or decreased. Early in the respiratory phase, elevated creatine phosphokinase levels (as high as 3,000 IU/L) and hepatic transaminases (two to six times the upper limits of normal) have been noted.

The Center for Disease Control CDC has added laboratory criteria to Case Definition for SARS:
SARS case is laboratory-confirmed if one of the following criteria is met:


• Detection of SARS-CoV RNA by reverse transcriptase-polymerase chain reaction (RT-PCR), which must be confirmed by a second PCR test.


• Detection of antibody to SARS-CoV by indirect fluorescent antibody (IFA) or enzyme-linked immunosorbent assay (ELISA).


• Isolation of SARS-CoV in tissue culture.


• If all of the above mentioned tests are negative within 21 days, the antibody test must be repeated after 21 days.

Transmission:
The transmission of SARS appears to occur predominantly by direct contact with infectious material, including dispersal of large respiratory droplets. However, it is also possible that SARS can be spread through the airborne route. SARS is similar to tuberculosis, where it appears to spread by direct contact with respiratory secretions, but touching contaminated objects is a potential concern.

SARS - Preventive measures
Centre for Disease Control CDC has recommended the use of N95 respirators, consistent with respiratory protection for airborne diseases, such as tuberculosis. Infectious material deposited on a respirator may cause it to become a vehicle for direct or indirect transmission. Therefore, additional precaution must be taken in special cases.

If You Are In Direct Contact With SARS Patient:
If by any means you are in contact with SARS patient, follow these instructions carefully.

1. Use Of Respirator;
CDC recommends use of N95, N99, N100 respirators
One can also opt for following respirators.
When elastomeric (rubber) or powered air purifying respirators (PAPRs) are used, their reusable elements should be cleaned and disinfected after use, in accordance with manufacturer's recommendations.

Respiratory protective devices with a filter efficiency of 95% or greater (e.g., N95, N99, N100) may not be available in some settings due to supply shortages or other factors. In this situation, a surgical (procedure) mask should be worn, but surgical masks may not adequately protect against aerosol or airborne particles, primarily because they allow for leakage around the mask and cannot be fit tested.

Precautions while using respirators:


• Respirators should be used in the context of a complete respiratory protection program. This includes training and fit testing to ensure a proper seal between the respirator's sealing surface and the wearer's face.


• Once worn in the presence of a SARS patient, the respirator should be considered potentially contaminated with infectious material, and touching the outside of the device should be avoided. Upon leaving the patient's room, the disposable respirator should be removed and discarded, followed by hand hygiene.


• Consider wearing a loose-fitting barrier that does not interfere with fit or seal (e.g., surgical mask, face shield) over the respirator.


• Remove the barrier upon leaving the patient's room and perform hand hygiene. Surgical masks should be discarded; face shields should be cleaned and disinfected.


• Remove the respirator and either hang it in a designated area or place it in a bag. (Consider labeling respirators with a user's name before use to prevent reuse by another individual.)


• Use care when placing a used respirator on the face to ensure proper fit for respiratory protection and to avoid contact with infectious material that may be present on the outside of the mask.


• Perform hand hygiene after replacing the respirator on the face.

2. Hand Hygiene;
Hand hygiene is urged for all contact with suspect SARS patients or objects that may be contaminated with the virus that causes SARS, including hand washing with soap and water; if hands are not visibly soiled, use alcohol based cleaners. Patients with SARS pose a risk of transmission to close household contacts and health care personnel in close contact.

3. Advice for patients
The following infection control measures are recommended for patients with suspected SARS in households or residential settings. These recommendations are based on the experience in the United States to date and may be revised as more information becomes available.


• SARS patients should limit interactions outside the home and should not go to work, school, out-of-home child care, or other public areas until 10 days after the resolution of fever, provided respiratory symptoms are absent or improving.


• Use of disposable gloves should be considered for any direct contact with body fluids of a SARS patient. However, gloves are not intended to replace proper hand hygiene. Immediately after activities involving contact with body fluids, like respiratory secretion, urine stool etc. hands should be cleaned. Gloves must never be washed or reused.


• Each patient with SARS should be advised to cover his or her mouth and nose with a facial tissue when coughing or sneezing. If possible, a SARS patient should wear a surgical mask during close contact with uninfected persons to prevent spread of infectious droplets.


• Sharing of eating utensils, towels, and bedding between SARS patients and others should be avoided.


• Household waste soiled with body fluids of SARS patients, including facial tissues and surgical masks, may be discarded as normal waste.


• Household members and other close contacts of SARS patients should be actively monitored by the local health department for illness.

Protective measures:

• Prompt identification of persons with SARS, their movements and contacts;


• Effective isolation of SARS patients in hospitals;


• Appropriate protection of medical staff treating these patients;


• Comprehensive identification and isolation of suspected SARS cases;


• Exit screening of international travelers;


• Timely and accurate reporting and sharing of information with other authorities and/or governments.