JEDDAH, 18 February — It’s Haj season and with tens of thousands of people gathering at one place or the other, one disease that one has to be extra careful about is influenza.
Growing awareness of meningitis prompts the average citizen and resident to get vaccinated regularly once every two years. Similar awareness is growing about influenza, one other disease that spreads rapidly due to close proximity with infected people.
“When you’ve people close together, a virus like influenza has a wonderful opportunity to spread,” Dr. John Oxford, professor of virology at St. Bartholomew’s and the Royal London Hospital, Queen Mary’s School of Medicine and Dentistry, told Arab News in a recent interview.
Influenza typically affects the upper and lower respiratory tracts, the nose, sinuses, throat, lungs and the middle ear. It is spread from person to person by coughing and sneezing. The infected person may continue to spread the virus for an additional four to six days after the start of symptoms. Explosive outbreak of influenza occurs each winter and typically lasts six to eight weeks. These outbreaks result in on an average 10 percent of adult population being infected with the virus and cause 10,000 to 40,000 deaths each year in the US alone.
Oxford, who was here to give a presentation on “New treatment for pandemic and epidemic influenza” at a seminar organized by Hoffmann-La Roche Pharmaceuticals at Hilton Jeddah, said: “Despite new advances, influenza is not yet under control worldwide.” Asked whether vaccine against influenza could play a major role in controlling the disease, Oxford, who has co-authored two standard texts on influenza and published 250 scientific papers, said: “Vaccine is very good but is concentrated on and targeted at vulnerable groups like young children and elderly people. Vaccine is specially used to prevent hospitalization of vulnerable people, but that leaves rest of the people vulnerable to the disease. Vaccine cannot be given to all because of its shortage. Moreover, studies suggest that vaccine is between 30 and 90 percent effective. If an unpredicted new strain of virus appears after the vaccine has been manufactured and distributed, individuals who have received the vaccine will not be protected. Recommendations for vaccination vary from country to country, but generally it is reserved for high risk groups (children, the elderly and those with underlying physical illness) and residents of health care and nursing facilities and other long-stay facilities where rapid spread is likely.”
However, he added: “Vaccine is important. It’s high-tech. Every year, it has to be reformulated because the virus changes. Of course, some of the new drugs now available will not replace vaccine but work together. Flu vaccine has to be taken every year like meningitis vaccine every two years. No doubt, the meningitis organism changes, but the flu virus changes rapidly.”
One of the defining characteristics of influenza is that symptom onset is abrupt — sufferers can often remember the exact time at which the illness began. Symptoms may include fever/chills, cough muscle aches and pains, headaches and fatigue/weakness. These symptoms are a direct consequence of viral replication. If quickly diagnosed, drugs can have a quick influence, he says.
A crucial differentiation between a viral attack and influenza is the speed with which the symptoms come on. “You may be sitting in a restaurant sipping coffee and within 20 minutes or so you begin to feel ill with cough, headache, temperature, shivering, aches and pains. You feel like taking a rest,” he said and recalled the year before last when 20,000 people died of influenza in England within weeks. Half of them were elderly people and the other half in the younger age groups.
Referring to new drugs, he said they would help focusing attention on the disease. “The focus will enable people to differentiate between a common cold and flu. You can relax with a common cold but not with influenza. Once diagnosed, management has to be quick. Today doctors can manage influenza. In olden days people suffering from influenza usually took a paracetamol and relaxed.”
Oxford cautioned that if especially elderly people neglected influenza, it might lead to secondary complications like bronchitis, sinusitis, otitis, pneumonia and also myocarditis and encephalitis. Also, risking complications are individuals whose immune system is compromised by, say, HIV treatment or steroid use; young children; those already suffering from chronic illnesses like chronic respiratory, cardiac or renal disease; and diabetics.
Sometimes, in spite of vaccination, you get influenza. In 1918 influenza killed 50 million people worldwide, in 1957 some five million and in 1968 three million, all in a matter of a few weeks. “This is not a virus to be taken lightly because if not controlled and managed a huge global outbreak could follow.”
Oxford’s research interest is the pathogenicity of influenza, in particular the 1918 Spanish influenza strain, which he combines with conducting clinical trials using new influenza vaccines and antiviral drugs. This research has been featured on Science TV programs Channel recently in the US and Europe. He was also part of a major science program on the National Geographic Channel. He is scientific director of the college research virology company called Retroscreen Ltd. The hospital’s unique collection of tissue samples has also enabled Oxford and his team to study encephalitis lethargica and its possible links with the 1918 influenza. A natural extension to his work is to analyze samples from the Svalbard victims including brain tissue, which will be tested for the encephalitis lethargica. Nevertheless, influenza is a highly contagious viral illness that typically occurs during the winter months. It is characterized by a sudden and rapid onset of debilitating clinical symptoms, which affect the entire body, and “knocks the individual flat.”
Everyone is at risk of developing influenza, even patients who are normally very healthy may spend five to six days in bed and up to two weeks recovering from the infection. About 38 percent of all influenza related deaths occur in adults, and some 20 percent of the patients that die during epidemics were previously healthy. Every year, 100 million people are affected in Europe, Japan and the US alone.
Influenza epidemics can occur virtually every year — although the extent and severity of each one varies widely. Worldwide influenza epidemics — known as pandemics — occur every 10 to 40 years and can affect between 25 to 50 percent of the population.
Many patients use over-the-counter medications, such as paracetamol to reduce the symptoms of influenza. These agents do not attack the underlying cause of the illness, the virus, and so their potential to stop and prevent and development complications is limited.
He says, investigators have had success with a new class of drugs — neuraminidase inhibitors — that attack the virus, the root cause of the influenza infection. “Ongoing search for a convenient orally administered medicine led to the development of Tamiflu (oseltamivir phosphate). The medication targets one of the two major surface structures of the influenza virus the neuraminidase protein. The neuraminidase site is virtually the same in all common strains of influenza. If neuraminidase is inhibited, the virus is not able to infect new cells. Tamiflu fights the influenza virus and meets the need for an easy and reliably administered influenza treatment.”