‘Seek care immediately’: Four dead in outbreak of waterborne disease following Brazil floods

Aerial view of floods in Eldorado do Sul, Rio Grande do Sul state, Brazil
The southern state of Rio Grande do Sul was hit by unprecedented floods this month - NELSON ALMEIDA/AFP via Getty Images

More than 50 cases of the waterborne leptospirosis disease have been confirmed in the wake of Brazil’s devastating floods, leaving at least four dead with warnings of additional fatalities to come.

The southern state of Rio Grande do Sul was hit by weeks of unprecedented floods in May after being inundated with torrential rains. More than 2.3 million people have been affected, 165 killed, and at least 581,000 displaced by the climate disaster.

Now, the health department is battling a new threat – an outbreak of leptospirosis.

Fifty-four cases of the zoonotic disease – which is spread through water contaminated with infected animals’ urine – have been confirmed, and as many as 800 suspected cases are being investigated.

With many towns still under water, authorities have warned additional fatalities are likely.

Katiane Mello (R) leaves her flooded home in a boat navigating a street in Eldorado do Sul, Rio Grande do Sul state, Brazil, on May 9, 2024
A resident leaves her flooded home by boat navigating a street in Eldorado do Sul - CARLOS FABAL/AFP via Getty Images

“The water is going to recede but there’s still going to be a lot of it, and leptospirosis can survive in that water for weeks,” said Dr Max Eyre, a leptospirosis expert at the London School of Hygiene and Tropical Medicine, working in Brazil. “It’s a serious problem and likely to get a lot worse.”

The disease is caused by spirochete bacterium from the genus Leptospira and tends to occur during heavy rainfall or flooding. It is estimated to cause more than one million human cases and almost 60,000 deaths globally each year.

Symptoms range in severity from a mild disease with fever, chills and headaches lasting around a week, to life-threatening illness which can lead to kidney damage, liver failure, meningitis and pulmonary haemorrhage.

Of those who are hospitalised, between five and 16 per cent die.

“Seek care immediately,” said health minister Nísia Trindade. “We cannot tell people not to have contact with water, because this is the situation in most municipalities in Rio Grande do Sul, but try to wear boots, gloves, be aware of these symptoms and seek medical attention as soon as possible.”

Locals move in boats following floodings due to heavy rains in Porto Alegre, Rio Grande do Sul state
Locals use boats to move around their neighbourhood following the floods - NELSON ALMEIDA/AFP via Getty Images

The health department has also urged people to avoid consuming water or food that might be contaminated with flood water.

The disease is understood to be able to affect every mammal in the world – and has even been detected in seals in New Zealand and California – but is often spread in urban settings via rats.

“Affected rats shed the disease in their urine, they deposit it always and everywhere. In one study in Salvador [in the northeastern state of Bahia] we found about 80 per cent of rats were actively shedding,” says Dr Eyre. “Then suddenly a flood comes and carries it into peoples houses.”

Many of the areas affected in Brazil are informal settlements, with open sewers and poor rubbish collection systems, which leads to a “huge proliferation of rats living among the people,” according to Dr Eyre.

The four victims were all men aged between 33 and 67 and lived in different cities.

“Everyone is at risk if they have contact with water or soil without waterproof boots,” warned Dr Eyre, adding that the confirmed cases are only the “tip of the iceberg”.

People walk through a flooded street in the Chacara neighborhood in Eldorado do Sul, Rio Grande do Sul state, Brazil
Anyone who comes into contact with water or soil without waterproof boots is at risk - ANSELMO CUNHA/AFP via Getty Images

People affected need to receive early treatment with antibiotics to avoid severe infections, but this can be difficult in flood settings as healthcare infrastructure collapses.

The disaster struck more than 80 per cent of the state’s municipalities and has affected more than 3,000 health establishments, such as hospitals, pharmacies and clinics, according to the federal government’s health research institute Fiocruz.

“One of the main problems after flooding is that people don’t have access to healthcare,” said Dr Eyre. “With leptospirosis they can also be misdiagnosed – it has non-specific symptoms like headaches and malaise – and doctors might tell them to go home. Education and communication about the disease is important.”

Given the scale of the crisis, the health minister has urged doctors to prescribe antibiotics before test results are confirmed. “It is not necessary to confirm the disease by testing to apply the medication,” Ms Trindade said. “The symptoms are enough for healthcare professionals and doctors to recommend it.”

Aerial view of the flooded Beira-Rio stadium of the Brazilian football team Internacional in Porto Alegre, Rio Grande do Sul state, Brazil
Aerial view of the flooded Beira-Rio stadium of the Brazilian football team Internacional in Porto Alegre - ANSELMO CUNHA/AFP via Getty Images

Authorities had previously predicted a surge in infectious diseases, including leptospirosis and hepatitis B, as sewage mixed into the floodwaters. They are also concerned about respiratory and infectious diseases, and have urged flood victims to be vaccinated against influenza, Covid-19, tetanus, hepatitis A and rabies.

Dr Eyre noted that it is common for leptospirosis to come hand-in-hand with other diseases.

“Leptospirosis is very climate dependent, and one of the classic issues is that it usually comes at the same time as other diseases like zika, dengue,” he said, noting that Brazil has been battling a major dengue epidemic this year.

Brazil sees approximately 4,000 annual cases of the disease annually, with a 10 per cent fatality rate, according to researchers. Outbreaks occur primarily during the rainy season and mostly affect young adults between the ages of 20 and 49.

The clean up operation also increases the risks of injuries from venomous animals such as scorpions, snakes and spiders which had sought shelter in former houses.

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