Always on Alert

In 2005, following a spate of African swine fever outbreaks in the Democratic Republic of the Congo, Gerrit Viljoen, working for the Food and Agriculture Organization of the United Nations (FAO) and the IAEA, visited a piggery outside Kinshasa. Viljoen was there to train local scientists in disease sampling techniques and prepare them for potential outbreaks. What he witnessed still preys on his mind.

Over a dramatic three days, the highly contagious swine pathogen causing the disease swept through the farm, killing all of its 5000 pigs. As tragic as that outbreak and the devastation it wrought on livelihoods were, African swine fever fortunately stops at pigs and does not infect people. But that’s not true for all animal diseases. Many of today’s most contagious and deadly infectious diseases — seven out of every ten — originate from animals. We call them zoonotic diseases or zoonoses.

By providing training, equipment, chemical reagents and technical expertise, the IAEA, in partnership with the FAO, has contributed to bringing some of the world’s most dangerous and damaging diseases, including COVID-19, under control. The IAEA’s response to the ongoing pandemic is the latest in a string of efforts to combat zoonoses, including Zika, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), Rift Valley fever, avian influenza, brucellosis and Ebola.

Nuclear science saving lives

In late 2013, one of the worst and most widespread outbreaks of Ebola ever experienced began. Spread through contact with the blood or bodily fluids of those infected with the disease, Ebola cases rapidly proliferated in Guinea, Liberia and Sierra Leone. In August 2014, the World Health Organization (WHO) declared the region’s Ebola epidemic an international public health emergency. Over two and a half years, the virus killed more than 11 000 people — 40 per cent of those infected. Authorities managed to control the outbreak, saving tens of thousands of lives.

Always on alert for potential outbreaks, already in 2012, the IAEA was informed of Ebola incidents in Central and Eastern Africa and began providing support. By the time of the large outbreaks in West Africa, the IAEA had in place primers and protocols to help identify strains of Ebola — the first step towards controlling the disease. Along with the United States of America’s Centers for Disease Control and Prevention (CDC) and National Institutes of Health (NIH), countries like South Africa and international partners like the WHO, the IAEA and the FAO helped in validating polymerase chain reaction (PCR) test results (see infograph), provided equipment and trained experts.

“Our training went beyond how to get accurate PCR test results; we also gave training on personal protective equipment (PPE) to all medical and veterinary staff to try and ensure that all doctors and scientists involved took the precautions needed when dealing with the Ebola virus itself,” said Viljoen, now Head of the Animal Health and Production Section at the Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture. While the Ebola outbreak that brought West Africa to a standstill has ended, the IAEA is still on the trail of Ebola, now in the Democratic Republic of the Congo.

“The threat of Ebola has not gone away, but we can monitor it and act before future outbreaks occur by surveying Ebola’s viral reservoirs and virus hosts, such as certain bat species,” said Viljoen. Identifying new strains of the disease and analysing the mortality rate, transmissibility and infectivity will play a key role in addressing the disease and stopping future outbreaks.

Staying ahead of outbreaks

Similarly, the avian influenza virus strain H5N1 and other related strains such as H5N8 and H5N6 are an ever-present threat for poultry and people around the world. Originating in Asia but carried by migratory birds, this sometimes deadly to humans zoonotic disease has the potential to appear in other regions, including Europe and Africa. In 2017, it hit Uganda.

Unexplained bird mortalities began to appear in Uganda’s western region, and, at the country’s request, an IAEA emergency response team was dispatched to investigate. “We were already tracking the spread of H5 viruses across Asia, Europe and Africa, and we suspected that it might soon appear in this area. When these birds started dying, we knew we had to act quickly,” said Giovanni Cattoli, Head of the Animal Production and Health Laboratory of the Joint FAO/IAEA Centre, and an international expert on avian influenza research.

The IAEA uses stable isotopes naturally present in bird feathers and droppings to identify which areas waterfowl have visited during their migrations. Correlated with data of confirmed H5 cases, this information was used by the IAEA to trace infections moving with birds from China to the Russian Federation, across Europe and into Africa. Test results confirmed that the bird deaths were caused by the H5N8 strain. With IAEA support, Ugandan authorities were able to act quickly, retrieve bird corpses and implement measures to reduce human and livestock exposure to the disease.

“The faster you are at detecting avian influenza, the faster you can make efforts to limit the exposure of domestic birds and people,” said Cattoli. The disease was later detected in the eastern part of the Democratic Republic of the Congo, and, at the start of 2021, an avian influenza outbreak was confirmed and brought under control in Senegal with IAEA support.

Early detection of zoonotic disease outbreaks is an increasingly important aspect of the IAEA’s work. Last year, the IAEA launched the Zoonotic Disease Integrated Action (ZODIAC) project. Through a systematic and integrated approach, ZODIAC strengthens countries’ preparedness and capabilities for detecting and responding to zoonotic disease outbreaks.