What are the risks of a bird flu outbreak to people living with HIV/AIDS?

It’s been described as “the biological equivalent of the Boxing Day tsunami” — an outbreak of avian influenza in Australia could cause thousands of deaths, officials have warned, and people living with HIV/AIDS are among the groups at risk.

But while new cases of the deadly H5N1 influenza infection are occurring at an increasing rate across the south-east Asian region, federal health authorities have sought to reassure the public that Australia is well prepared for any outbreak, while urging us to be ‘Prepared and Protected’ in case a pandemic emerges in the coming months.

It’s not surprising that the government is concerned. The World Health Organisation has warned that as many as 150 million people could die if the virus becomes transmissible between humans. “It’s like a combination of global warming and HIV/AIDS, 10 times faster than it’s running at the moment,” the WHO’s Dr David Nabarro said recently.

To date, no cases have been identified of the virus passing from human to human, however many experts say it is only a matter of time before that occurs. What happens next depends on the effectiveness and speed with which global and national management plans are put in to place.

Australia’s chief medical officer has warned that an outbreak of bird flu could result in more than 13,000 deaths, 58,000 hospitalisations and 2.6 million people seeking medical attention, all within a short period.

Among the groups likely to be disproportionately affected should an outbreak occur in Australia are people living with HIV/AIDS, especially those with lower T-cell counts, as well as young children, the elderly and others with impaired immune function.

While there’s no reason to panic, it is recommended that everyone understand ahead of time what they can do to protect themselves.

How it spreads

Epidemics of influenza (flu) occur almost every year, typically during the winter months. Caused by a virus, most cases of flu are relatively mild and, while deaths do occur, most people recover within a couple of weeks. Different flu viruses can infect many different animals; ‘avian influenza’ infects birds such as chickens, ducks and waterfowl and can cross to humans, either directly or via another host animal such as pigs.

The deaths to date from the current outbreak have all been in people who caught the virus from infected birds. The worry is that if a person with human flu became infected with the bird flu virus as well, the virus would mutate into a form which can be transmitted from person to person.

Serious influenza pandemics occur on average about three times per century, whenever new subtypes of the influenza virus emerge and spread from person to person. The worst-ever pandemic occurred in 1918-19, causing more than 40 million deaths worldwide, 11,500 in Australia. Since then, less severe pandemics have occurred in 1957-58 and 1968-69.

While it’s impossible to predict when a pandemic might occur, there is widespread agreement that further pandemics are inevitable and one may be imminent.

Influenza spreads from person to person in droplets of liquid carried by coughs and sneezes. If these droplets are inhaled by an uninfected person, the virus can lodge in mucous membranes inside the nose and throat to cause flu.

Protecting yourself and others

Whether dealing with the doomsday scenario of a global flu pandemic or the common-or-garden variety seasonal flu, the measures to prevent spreading the virus are much the same.

If you have the flu, or any other respiratory illness, you should use a clean tissue when you cough or sneeze. The tissue should then be disposed of and you should wash your hands thoroughly with soap and water, then dry them with a clean towel.

Simple hand washing is perhaps the most effective way to prevent catching the flu. Most people catch the flu not from droplets in the air but by touching surfaces – door handles, for example – which have become contaminated with the flu virus. Regular hand washing (especially before meals) and avoiding contact between hands and face can prevent many infections.

As with any infectious illness, it’s recommended that if you do contract influenza you avoid, as much as possible, public places and close contact with people, especially those at greater risk of serious illness. If you don’t have the flu, there’s no need to hide from the world; just follow the hygiene precautions above and use common sense to avoid exposing yourself to unnecessary risk.

Having an annual flu shot will not protect from the H5N1 influenza strain – but it will protect against common-or-garden variety flu, which may be just as serious for people with reduced immunity and is certainly more prevalent.

The antiviral drugs Tamiflu and Relenza are available on prescription to help reduce the severity of symptoms; we don’t know for sure at this stage, however, how effective these drugs would be against this strain of flu. Both drugs are safe for people with HIV to take for short periods, and can also be taken as a preventative if you are travelling to an area where bird flu outbreaks have occurred.

While people living with HIV/AIDS have good cause to be concerned about this new threat, there is no cause for panic. Despite some of the doomsday scenarios being canvassed by the media, there is much that can be and is being done to reduce the impact of any influenza outbreak.