INFLUENZA: What Lies Ahead?

his disease knows no Despite all our technological stark reminder that 100 years ago international boundaries and advancements and surveillance the devastation of the 1918 Tkills more people than war abilities, mankind has not been Spanish Flu was evident or terrorism. There were more able to accurately predict a single worldwide. It is conservatively than 2.8 million new cases of it in severe pandemic. This year is a estimated that more than 50 Japan in the first week of February 2018. The Centre for Disease Control (CDC) reported 4000 deaths weekly due to it and its complications in the USA. In Hong Kong, schools were shut early for the Chinese New Year [16 Feb 2018] after an outbreak claimed over 120 lives. This year it is reported to be the worst outbreak since 2010 with mostly children and the elderly affected. No, we are not talking of a frightening new disease. In fact we are talking of the wily foe which annually somehow manages to outfox and outwit us by being able to undergo subtle changes that counters medical science’s best attempt to curb its rampant spread. We are talking of the influenza virus.

By Dr Salim Parker TRAVEL SASTM Past President MEDICINE

?? | diversions WINTER 2018 million humans lost their lives due to the disease with about 10 million fatalities in India. South Africa was the fifth most severely affected country with close to 500 000 deaths. Two waves were recorded in our country starting from Cape Town and Durban. The well-developed rail and sea transport system at that time facilitated the spread of the pandemic. Since the disease primarily affected young adults aged between Despite all our 18 and 40, a technological staggering 900 advancements and 000 children were orphaned surveillance abilities, mankind in our country. has not been able to It was always accurately predict a single occurs there. The been known to affect wild birds considered that severe pandemic. 1957 pandemic and poultry on the Chinese most pandemics would spread from mainland mainland. These viruses, such as originate from Asia. Most of China and spread wordwide H5N1, occasionally crossed the the earth’s land mass and within 6 months. The 1968 one species barrier and infected population is found there and started in Hong Kong and rapidly humans. When this happened, close interaction between humans spread. Avian influenza, more H5N1 had a 50% mortality in and animals most commonly commonly known as bird flu, has humans. Because of the frequent

?? | diversions WINTER 2018 TRAVEL MEDICINE interactions and numbers of humans and birds in the northern hemisphere, the rationale was that one of these influenza viruses would mutate into a virulent form and start the next human influenza pandemic. Again the virus was able to outmanoeuvre the unsuspecting human race. The H1N1 pandemic of 2009 started in Mexico in about March and very rapidly spread along the international travel routes. Since the vast majority of flights departing Mexico flew to North America and Europe, the disease, called swine flu, first manifested there before spreading to the rest of the world. By July Cold versus flu pic is from: httpcdtdesign.comwordpress20180126fhw-cold- 2009 virtually all countries had flu-prevention-campaign reported cases. Computer modelling has shown that thousands of kilometres from The swine flu pandemic also stopping the spread would have Antarctica to Central America and shed some important light on been near impossible. If for acquires different influenza animal-human virus transmission. example travel out of Mexico strains there and then takes it It is now known that humans was curtailed by 40%, the rate of back to the frozen wastelands transmit far more influenza the spread of swine flu would where the different viruses mutate viruses to swine than swine have been delayed by only two and exchange genetic material. transmit to humans. Human-to- days. If the traffic out of The potential exists that one of swine transmission is actually the Mexico was decreased by these mutated strains may key to the evolution of influenza 90%, the rate would It is now known be extremely infective diversity in swine and in effect, have slowed by only in humans and, if it humans sow the seeds of future that humans transmit two weeks! is carried somehow pandemics by infecting swine. We are far more influenza to large Influenza is often considered discovering more viruses to swine than settlements, may a trivial disease but the South and more about this swine transmit to initiate the next African death statistics tell a fascinating virus. A humans. pandemic. Of concern different horrifying story. type called H11N2 was is that the first human Tuberculosis is still the number discovered in Antarctica in case of H7N4, which occurs one killer in our country. Influenza 2014. What was fascinating about in birds, was documented on 14 and pneumonia, which is grouped this virus was that it contained February 2018. In March 2018 a as one entity for death statistics genetic material from strains H1N2 specie that most likely purposes, has been the second found in the northern and resulted from the genetic leading cause of death from 2009 southern hemispheres. It has been interchange between the current till 2013. The introduction of a postulated that migratory birds circulating H1N1 and H3N2 very effective vaccine against such as the giant petral flies strains was described. pneumonia had led to

?? | diversions WINTER 2018 influenza/pneumonia falling to the once hospitalized. Influenza TRAVEL MEDICINE 6th leading of death by 2015. But vaccination reduced statistics can be deceiving. hospitalisation of working-age Diabetes was the leading cause of persons with diabetes mellitus by severe effects due to influenza natural deaths in South African 79%. Influenza vaccination was infection and vaccination has ladies in 2016. We have to associated with a significant been proven to be associated with consider the relationship decrease in risk for hospital better outcomes. between diabetes admission due to The cost to the economy Patients suffering and influenza as stroke, heart failure, during the winter season can be the effects of from other medical and influenza or staggering. In 2013 the direct and high blood conditions such as heart pneumonia in one indirect costs was 26 billion glucose levels failure also benefit from study. Patients dollars for the 8 million afflicted in predisposes vaccination as deaths due to suffering from the USA. For 2018 36 million to infections influenza related other medical cases were postulated, leading to and its complications decreased conditions such as 750 000 hospitalisations and 56 complications. heart failure also 000 deaths at a cost of 87 billion by up to 50%. Diabetes mellitus benefit from vaccination dollars. Preventing an epidemic has been associated with as deaths due to influenza through vaccination would be a worsened outcome of influenza related complications decreased about one tenth of the cost of as it tripled the risk of by up to 50%. There is an managing an outbreak. Influenza hospitalisation following infection. association between influenza and vaccination should be high on the It also quadrupled the risk of acute myocardial infarctions. priority list for most citizens, intensive care unit admission Asthma sufferers have more especially those at high risk.

?? | diversions WINTER 2018