As cases of the avian flu virus seem to worsen in southern China bordering Hong Kong, citizens and visitors are again urged to take precautionary measures against the spread of the disease.

The lethal virus, which affects fowl and migratory bird species and could be passed on to humans, claimed the life of a bus driver from Shenzhen. Thousands of chicken had already been culled in Shenzhen, a city in Guangdong province with close to 10 million in population.

This is the first human fatality in 18 months as the fight to eradicate the disease continues.

The 39-year-old man, surnamed Chen, died in Shenzhen of complications due to severe pneumonia, kidney, liver and heart failure caused by the H5N1 virus.

A spokesman for the Hong Kong health department said in a statement authorities would heighten their vigilance "and continue to maintain stringent port health measures in connection with this development".

Health authorities in China have also vowed to stay in "close contact and work together" with Hong Kong and "jointly step up measures in controlling the epidemic", the official Xinhua news agency said.

Aside from China, countries in Southeast Asia including Vietnam, Indonesia, and Malaysia have had human cases of H5N1 since 2009.

If you are a frequent traveller to these areas, prevention and taking more precaution measures are advised.

If you think you have been exposed to avian influenza, call your health care provider before your visit. This will give the staff a chance to take proper precautions that will protect them and other patients during your office visit.

Tests to identify the avian flu exist but are not widely available. A test for diagnosing strains of bird flu in people suspected of having the virus gives preliminary results within four hours. Older tests took two to three days.

Your doctor might also perform the following tests:

  • Auscultation (to detect abnormal breath sounds)
  • Chest x-ray
  • Nasopharyngeal culture
  • White blood cell differential

Other tests may be done to look at the functions of your heart, kidneys, and liver.

The New York Times reported that the symptoms of avian flu infection in humans depend on the strain of virus.

Infection with the H5N1 virus in humans causes typical flu-like symptoms, which might include:

  • Cough (dry or productive)
  • Diarrhea
  • Difficulty breathing
  • Fever greater than 100.4°F (38°C)
  • Headache
  • Malaise
  • Muscle aches
  • Runny nose
  • Sore throat