Influenza A(H1N1)
• New strain - never reported before
• Contains gene segments from 4 different influenza types:
– North American swine
– North American avian
– North American human and
– Europe/Asian swine
Where we are now
Confirmed Cases Reported Worldwide
Distribution by Age
How dangerous is it?
• Deaths reported in Mexico
– Very little information on who are the most vulnerable
• Most cases diagnosed outside Mexico have had a mild disease
– Hospitalisations occur only in patients with underlying disease (Not sure why)
Case definition
source : Crisis Preparedness and Response Centre , Ministry of Health Malaysia , 29 April 2009
Symptoms
Diarrhoea and vomiting uncommon
Children
• Young children are less likely to have the usual influenza signs and symptoms, such as fever and cough
• Infants may present with fever and lethargy, and may not have cough or have other respiratory symptoms.
• Symptoms of severe disease in infants and young children may include apnea, tachypnea, dyspnea, cyanosis, dehydration, altered mental status, and extreme irritability
High Risk Groups for Complications if Infected
• all children aged 6 months--4 years (59 months)
• all persons aged >65 years
• children and adolescents (aged 6 months--18 years) who are receiving long-term aspirin therapy and who might be at risk for experiencing Reye syndrome after influenza virus infection
• adults and children who have chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, hematological, or metabolic disorders (including diabetes mellitus)
• adults and children who have immunosuppression (including immunosuppression caused by medications or by HIV)
• adults and children who have any condition (e.g., cognitive dysfunction, spinal cord injuries, seizure disorders, or other neuromuscular disorders) that can compromise respiratory function or the handling of respiratory secretions or that can increase the risk for aspiration
• residents of nursing homes and other chronic-care facilities.
• pregnant ladies
Transmission
• Coughing or sneezing
• Touching contaminated surfaces/objects and then touching mouth or nose
Survival of the Virus
• Hard non-porous surfaces 24-48 hours
– Plastic, stainless steel
• Recoverable for > 24 hours
• Transferable to hands up to 24 hours
• Cloth, paper & tissue
– Recoverable for 8-12 hours
– Transferable to hands 15 minutes
• Viable on hands <5> • 1 day prior to the illness onset to 7 days after onset
• Day before onset = Day -1
• Day of onset = Day 0
• Days after onset = Days 1-7
Treatment
• Zanamivir (or) Oseltamivir
• Initiated as soon as possible after the onset of symptoms
• Duration of treatment = 5 days
• Duration of prophylaxis = 10 days from last exposure Is the human seasonal influenza vaccine effective against influenza virus A(H1N1)?
• There are certain similarities between the usual H1N1 human influenza viruses (covered by the seasonal vaccine) and the novel influenza virus A(H1N1) so one cannot rule out some level of cross-protection, but this is likely to be only partial.
• In any case, investigations need to be undertaken to determine whether this is the case.
• Those investigations are under way, but will take quite some time.
Prevention
• Covering nose and mouth with a tissue when coughing or sneezing, dispose the tissue in the trash immediately after use
• Handwashing with soap and water, especially after coughing or sneezing
• Cleaning hands with alcohol-based hand cleaners
• Avoid close contact with sick people
• Avoid touching eyes, nose or mouth with unwashed hands (This is especially vital when you are in the open public)
• If you are sick with influenza, stay home from work or school and limit contact with others to keep from infecting them, wear a surgical mask if necessary.
For more current update, please visit http://www.moh.gov.my/
Prepared by Dr Tan Wan Lin (information courtesy of Dr Chow Ting Soo, Head of Department, Infectious Disease Unit, Penang Hospital)
