Cerrar

Bird flu outbreaks in different parts of the world keep local and international public health agencies on high alert. For example, Cambodia International Health Regulations (IHR) reported two cases of avian influenza (H5N1) in humans on February 23, becoming the first country to report this infection in 2023. Investigation into the route of transmission and other potential cases is ongoing course.

The avian flu, also known as bird flu, is a highly contagious viral disease that affects birds, especially poultry. While the virus primarily spreads among birds, it can also infect humans, leading to severe respiratory illness and even death in some cases. The disease has been a concern for public health authorities worldwide since the outbreak in 2003.

The risk of an avian flu pandemic in Latin America and the Caribbean is compounded by several factors. One of the main factors is the presence of a large number of small-scale poultry farms and backyard chicken coops in the region. These farms are often poorly regulated and lack proper biosecurity measures, making them more susceptible to the spread of the virus.

The Pan American Health Organization (PAHO) issued an alert last January in response to the increased detection of avian influenza outbreaks in birds in ten countries in the Region of the Americas and the recent confirmation of the first case of human infection of avian influenza A(H5) in South America.

In an epidemiological alert, PAHO stressed the importance of controlling infection in birds as the key measure to reduce the risk to humans and recommended that countries strengthen surveillance for seasonal and zoonotic influenza in animal and human populations.

The Organization also reiterated its guidelines on early laboratory diagnosis in human and animal samples and the respective investigation of cases and contacts, and recommended that these and other surveillance, prevention and control actions be carried out in coordination between the health, agriculture and environmental sectors.

In the region, the influenza A(H5N1) virus was first identified in domestic and wild birds in December 2014 in North America. Since then and until the first week of January 2023, Canada, Chile, Colombia, Ecuador, Honduras, Mexico, Panama, Peru, the United States and Venezuela have detected outbreaks of this virus in domestic, poultry and/or wild birds.

Infections of this virus in humans, which can often have severe symptoms, have been much less frequent. But whenever avian influenza viruses circulate among birds, there is a risk of sporadic human cases. So far, two human infections have been confirmed in the region: the first in April 2022 in the United States and the second on January 9, 2023 in Ecuador.

In general, human cases are occasional and, when they have occurred, have not spread easily from person to person. However, the risk of establishing sustained human-to-human transmission exists and could eventually lead to an outbreak or even a pandemic.

The real risk of outbreaks

In recent years, the virus has caused sporadic outbreaks in some parts of the world, including Latin America and the Caribbean. While the number of cases in the region has been relatively low compared to other regions, such as Asia, concerns remain about the potential for avian flu to become the next pandemic in Latin America and the Caribbean.

The avian flu virus is primarily transmitted through direct contact with infected birds or their droppings, but it can also spread through the air. If the virus mutates to a form that can be easily transmitted from person to person, it could cause a pandemic. The possibility of such an outbreak is a concern, given the high population density in urban areas of the region.

People at risk are those exposed to infected birds (domestic, wild or captive), such as poultry keepers and personnel involved in outbreak control. Health care workers are also at risk of infection if adequate prevention and control measures are not observed. 

It is recommended the use personal protective equipment and other hygiene and sanitation measures.

Sources: Nature 615, 196-197 (2023); PAHO,