The World Organisation for Animal Health (WOAH) announced that Liberia had reported an outbreak of highly pathogenic H5N1 avian influenza, commonly known as bird flu, on a poultry farm in Bong County. This marks a significant development in the ongoing global spread of the virus, which has devastated poultry populations and raised concerns about potential risks to human health and food security.
The outbreak, detected in February 2025, shows the challenges faced by countries in controlling this highly contagious disease and highlights the need for robust biosecurity measures and international cooperation.
Details of the Outbreak
According to WOAH, the H5N1 outbreak occurred on a poultry farm housing 26,000 birds in Liberia’s Bong County, a central region known for agricultural activity. The virus killed 18 birds, a relatively small number compared to the flock size, but the rapid spread of H5N1 prompted swift action. Liberian authorities vaccinated approximately 25,800 birds in the affected flock, though the timing of the vaccination—whether preemptive or post-outbreak—remains unspecified.
The H5N1 strain is notorious for its high pathogenicity, meaning it can cause severe illness and high mortality rates in poultry. Globally, the virus has led to the culling of hundreds of millions of birds over the past few years, disrupting food supply chains and driving up prices for poultry products, particularly eggs.
In Liberia, where poultry farming is a critical source of income and nutrition for many communities, this outbreak poses a significant threat to local livelihoods and food security.
Global Context of H5N1 Spread
The H5N1 virus is part of a broader wave of avian influenza that has swept across the globe since 2020, affecting wild birds, poultry, and, in rare cases, mammals, including humans. The virus is primarily spread by migratory wild birds, which can introduce it to domestic flocks through droppings or direct contact. In recent years, H5N1 has been reported in numerous countries, including the United States, Bosnia, Senegal, and the Philippines, illustrating its transboundary nature.
In the United States, for example, H5N1 has infected over 136 million birds since 2022, contributing to record-high egg prices. The U.S. Department of Agriculture (USDA) reported a concurrent outbreak of the rarer H5N9 strain alongside H5N1 on a California duck farm in January 2025, highlighting the virus’s ability to evolve and present new challenges.
The spread of H5N1 to mammals, such as dairy cows and cats in the U.S., has further raised alarms about its potential to adapt and pose a greater risk to humans.
In West Africa, countries like Senegal and Togo have also reported H5N1 outbreaks in recent years, often linked to wild bird populations. Senegal’s 2023 outbreak, for instance, was traced to migratory birds near the Langue de Barbarie National Park, emphasizing the role of ecological factors in the virus’s spread. Liberia’s outbreak adds to the region’s challenges, where limited veterinary infrastructure and resources can hinder rapid response efforts.
Health and Economic Implications
While H5N1 primarily affects birds, its potential to infect humans is a growing concern. According to WOAH, human infections are rare and typically occur through close contact with infected birds or contaminated environments. Between 2005 and 2020, approximately 850 human cases of H5N1 were reported globally, with a high mortality rate. In the U.S., nearly 70 human cases have been recorded since March 2024, including one fatality in January 2025, underscoring the virus’s potential severity.
The World Health Organization (WHO) has emphasized that H5N1 does not currently transmit easily between humans, reducing the immediate risk of a pandemic. However, experts warn that the virus’s spread to mammals, including dairy cows and cats, increases the likelihood of mutations that could enhance its transmissibility. A 2024 study published in Emerging Microbes and Infections noted that H5N1 infections in cats could serve as a “bridge” for the virus to infect other species, potentially including humans.
Economically, H5N1 outbreaks have far-reaching consequences. The culling of infected flocks disrupts poultry production, leading to supply shortages and higher prices. In the U.S., egg prices doubled from $2 per dozen in September 2023 to $4.16 in December 2024 due to H5N1-related losses. In Liberia, where small-scale poultry farming supports many households, the outbreak could exacerbate food insecurity and economic hardship, particularly in rural areas like Bong County.
Response and Prevention Strategies
Liberian authorities have taken steps to contain the outbreak, including vaccination and likely implementing biosecurity measures such as restricting poultry movement and disinfecting farm equipment. WOAH recommends strict biosecurity practices, such as keeping poultry away from wild birds, maintaining hygiene in poultry housing, and promptly reporting illnesses or deaths to veterinary services.
Globally, responses to H5N1 vary. In the U.S., the USDA relies on a “stamping out” strategy, which involves culling infected flocks and enhancing surveillance. However, some experts argue that this approach has been insufficient to contain the current outbreak, prompting calls for poultry vaccination. Mexico, for instance, launched a large-scale vaccination campaign in 2023 to protect high-risk areas, though its effectiveness against new viral strains remains under evaluation.
The Food and Agriculture Organization (FAO) and WOAH have launched a ten-year Global Strategy for the Prevention and Control of High Pathogenicity Avian Influenza, emphasizing coordinated international action. FAO Deputy Director-General Beth Bechdol has called H5N1 a “transboundary” threat, urging countries to work together to protect food production systems and mitigate economic losses.
Liberia faces significant challenges in managing the H5N1 outbreak. Limited access to veterinary resources, diagnostic tools, and vaccines can hamper rapid response efforts. Additionally, the country’s reliance on smallholder farming makes it difficult to enforce biosecurity measures consistently. International support, including technical assistance and funding from organizations like WOAH and FAO, will be critical to strengthening Liberia’s capacity to control the virus.
