Epidemics that didn’t happen: Leptospirosis in Vanuatu

Leptospirosis, caused by the Leptospira bacteria, is one of the world’s most common and widely spread zoonotic diseases of epidemic potential. Epidemics are common when such environments experience heavy rainfall or flooding, and the increasing incidence of flooding brought on by climate change presents a growing public health challenge. The disease has emerged as a public health priority in Vanuatu, an archipelago nation in the South Pacific Ocean, because of its staggering toll on lives and livelihoods.

Between March 1 and 3, 2023, two severe tropical cyclones, Cyclone Judy and Cyclone Kevin, made landfall in Vanuatu. The cyclones devastated homes and critical infrastructure, including roads and airports. For several days, more than 80% of the population was left without food, electricity and basic hygiene facilities. Cyclone Kevin was particularly damaging to the country’s health system.

“The twin cyclones damaged many health facilities across the capital and across the country. Damage to roofing led to broken medical equipment and soiled stockpiles of essential medicines,” said Dr. Philippe Guyant, a medical officer at the World Health Organization (WHO) in Vanuatu. “The response teams had fewer resources to deal with the many public health threats the cyclones helped create because of the cyclones themselves.”

Leptospirosis is endemic in Vanuatu, but the extensive flooding caused by Judy and Kevin brought the bacteria out from the soil and into the water, creating ideal conditions for the spread of the disease and other water-borne illnesses.

Vanuatu’s response to mitigate an outbreak of leptospirosis

In recent years, Vanuatu’s MOH has been making strides to anticipate leptospirosis outbreaks during the rainy season in order to minimize the public health impacts and economic burden posed by the disease. This includes ramping up the capacity of the nation’s laboratory facilities, training frontline workers to spot symptoms and arming them with essential medications to treat suspected cases and engaging with local communities to make sure they understand how to keep themselves and each other safe. When the twin cyclones hit, the MOH was able to mount a response building on these ongoing preparedness efforts.

Once warnings were issued for Judy and Kevin, the surveillance unit held daily meetings with frontline workers across the country to ensure they were trained to spot the symptoms of leptospirosis and other water-borne diseases and that they were equipped with medications to treat any suspected cases. Later, when the cyclones made landfall, medical teams were deployed to the hardest-hit areas—because those were also the areas most likely to experience public health threats like leptospirosis in the aftermath. Frontline workers based in those areas were given priority on rapid diagnostic tests and medications and trained to alert the MOH on any cases and follow up with any patients in need of attention.

In addition to deploying all its available medical staff, Vanuatu also engaged its retired nurses to make up for ongoing staff shortages. From March 6 to 16, when the country was placed on “red alert” for leptospirosis, those workers identified 10 cases. And within four weeks of the cyclones making landfall, they had alerted the surveillance unit to 19 cases and three deaths, most of which came from Vila Central Hospital in the nation’s capital.

The NHEOC, led by the MOH and co-led by WHO, deployed mobile clinics around Port Vila, where around 20% of the population lives. These teams went into the affected communities delivering information on how to stay safe from leptospirosis and other water-borne diseases. Leptospirosis outreach and awareness activities were completed in six priority areas across Efate island, where Cyclone Kevin caused significant damage, ultimately reaching 7,875 people.

19 cases and three deaths were reported in the first four weeks after the cyclones. By May 26, this had risen to a total of 53 cases and 6 deaths, before cases slowed to a baseline rate typical for the time of year. In contrast, Vanuatu reported 99 cases in 2021 and 59 cases in 2022, illustrating how the MOH’s ongoing efforts to develop critical capacities and mount an effective response prevented a crisis from spiraling into disaster—even against a backdrop of two severe tropical cyclones making landfall.

While the disease is likely to remain endemic for the foreseeable future, WHO, MOH and other Ministries continue to partner with frontline workers and wider communities through a One Health approach to build on these outbreak response efforts, to make sure the nation is prepared to respond to future heavy rains—and any health threats that follow.