‘Brain-eating amoeba’
Source: By Alind Chauhan: The Indian Express
South Korea on 26 December 2022 reported its first case of infection from Naegleria fowleri or “brain-eating amoeba”, according to The Korea Times. The authorities said a 50-year-old Korean national, who had recently returned from Thailand, died 10 days after showing symptoms of the rare yet fatal infection.
The Korea Disease Control and Prevention Agency (KDCA) revealed that the man stayed in Thailand for four months before entering South Korea on 10 December 2022. A day later, he was taken to the emergency room after he began suffering from headaches, vomiting, stiffness in the neck and slurred speech, said the report.
The man died on 21 December 2022. Health authorities ran a host of tests to determine the exact cause of his death, which was found to be an infection caused by Naegleria fowleri.
What is Naegleria fowleri?
Naegleria is an amoeba, a single-celled organism, and only one of its species, called Naegleria fowleri, can infect humans, according to the US Centers for Disease Control and Prevention (CDC). It was first discovered in Australia in 1965 and is commonly found in warm freshwater bodies, such as hot springs, rivers and lakes.
How does it infect humans?
The amoeba enters the human body through the nose and then travels up to the brain. This can usually happen when someone goes for a swim or dive or even when they dip their head in a freshwater body. In some cases, it was found that people got infected when they cleaned their nostrils with contaminated water. Scientists haven’t found any evidence of the spreading of Naegleria fowleri through water vapour or aerosol droplets.
Once Naegleria fowleri goes to the brain, it destroys brain tissues and causes a dangerous infection known as primary amebic meningoencephalitis (PAM), according to the CDC.
What are the symptoms of PAM?
The CDC says the first signs of PAM start showing within one to 12 days after the infection. In the initial stages, they might be similar to symptoms of meningitis, which are headache, nausea and fever. In the later stages, one can suffer from a stiff neck, seizures, hallucinations, and even coma. The US public health agency also observed that the infection spreads rapidly and on average causes death within about five days. The fatality of PAM is as such that only four people have survived out of 154 known infected individuals in the United States from 1962 to 2021, the CDC mentions.
What is the treatment for the infection?
As the Naegleria fowleri infection is rare and progresses quickly, scientists haven’t been able to identify any effective treatments yet. At present, doctors treat it with a combination of drugs, including amphotericin B, azithromycin, fluconazole, rifampin, miltefosine, and dexamethasone.
Can climate change increase the spread of the infection?
According to the CDC, with the rising global temperatures, the chances of getting Naegleria fowleri infection will go up as the amoeba mainly thrives in warm freshwater bodies. The organism best grows in high temperatures up to 46°C and sometimes can survive at even higher temperatures.
Various recent studies have found that excess atmospheric carbon dioxide has led to an increase in the temperature of lakes and rivers. “These conditions provide a more favourable environment for the amoeba to grow. Heat waves, when air and water temperatures may be higher than usual, may also allow the amoeba to thrive,” the CDC website says. It also adds that initially the infections in the US were mostly reported in southern states, however, in recent years, they have been seen in northern states too.
So far, Naegleria fowleri has been found in all continents and declared as the cause of PAM in over 16 countries, including India.
