Avian influenza: are our feathers ruffled?

ABSTRACT

During the past century, three major influenza pandemics took place, leading to a devastating number of deaths. Pandemics occur through the emergence of a new strain of influenza virus that can infect humans, to which there is little pre-existing immunity and which spreads easily from human to human. The H5N1 influenza virus has the potential of becoming a pandemic virus, since it can infect humans and is highly pathogenic. All that remains is the final step of acquiring the genetic material to enable efficient human-to-human transmission. Therefore, the World Health Organization (WHO) has declared pandemic alert phase 3, the last phase before there is actual evidence of increased and efficient human-to-human transmission. In addition, every case of transmission of an avian influenza virus to humans is regarded by WHO as a cause for heightened alertness and surveillance. The circulation of highly pathogenic avian influenza viruses in large numbers among the poultry population in a growing number of countries is a major concern. Since the influenza viruses are highly unstable, the co-circulation of highly pathogenic animal viruses with human viruses may create opportunities for different species-specific viruses to exchange genetic material, giving rise to a new influenza virus to which humans would have little, if any, protective immunity. In this article, we highlight the current avian influenza situation from its different aspects with a special focus on the Hajj since we host over 2 million pilgrims a year in the holy cities of Mekkah and Medina.