Author- PS SWATHI, A student at Presidency university, Bangalore.
ABSTRACT :
Naegleria fowleri, a free-living amoeba, is the causative agent of Primary Amebic Meningoencephalitis (PAM). It was named in honor of Malcolm Fowler, an Australian pathologist after he and Rodney Carter identified it in cases of PAM following four fatal infections between 1961 and 1965. Despite its rarity, Naegleria fowleri is notorious for its staggering fatality rate of 98%. This amoeba thrives in warm, freshwater environments and can endure temperatures up to 45°C. Recent fatalities reported in the South Indian state of Kerala have sparked widespread concern and numerous inquiries regarding this pathogen. Given its rarity, many remain unaware of its severe lethality. This article aims to elucidate the life cycle of Naegleria fowleri, its devastating impact on human health, and preventive measures, and address common misconceptions and questions surrounding this amoeba.
IN-DEPTH ABOUT NAEGLERIA FOWLERI :
Naegleria fowleri, commonly known as the brain-eating amoeba, was discovered in 1965 by Malcolm Fowler. Recent fatalities in Kerala have heightened public concern, with four cases of Primary Amebic Meningoencephalitis (PAM) reported over the past two months, three of which have been declared fatal by a doctor in Palakkad district. PAM, although exceedingly rare, is a deadly disease caused by Naegleria fowleri. Due to its rarity, public knowledge about PAM is limited. Current data indicate that N. fowleri predominantly affects teenagers, particularly males. The United States reports the highest incidence of brain-eating amoeba infections compared to other regions with almost two-thirds of the total reports. Survivors of this disease are exceedingly rare for various reasons.
Naegleria fowleri sustains itself by feeding on bacteria in aquatic environments. Upon entering the human body, it begins to consume brain tissue, hence its moniker as a brain-eating amoeba. The Naegleria genus comprises over 40 species, yet only N. fowleri is known to be fatal to humans. Research suggests that this amoeba is attracted to chemicals used by nerve cells for communication. Once it enters the nose, it travels to the brain via the nasal passages, where it commences feeding on brain tissue.
LIFE CYCLE OF N. FOWLERI :
Naegleria fowleri undergoes three distinct stages in its life cycle. The first stage, the trophozoite stage, is the active, feeding phase during which the amoeba infects the human brain. In this stage, N. fowleri can be detected in Cerebrospinal fluid (CSF) or tissues. The second stage, the amoeba-flagellate stage, is a temporary phase that occurs when the trophozoite is exposed to environmental changes. During this stage, the amoeba neither feeds nor divides. The final stage, the cystic stage, enables the amoeba to withstand harsh conditions such as food scarcity or unfavorable temperatures by transforming into a cyst, thus allowing it to survive until conditions become favorable again.
WHERE IT IS FOUND?
Naegleria fowleri thrives in hot weather, with studies indicating its ability to withstand temperatures up to 45-46°C. This brain-eating amoeba necessitates a specific pH level for survival and, consequently, cannot persist in saline sea waters. It is predominantly found in fresh, warm water bodies such as lakes, rivers, ponds, untreated swimming pools, and other geothermal water sources.
SYMPTOMS :
The early symptoms usually start within 5 days of infection but it can vary and extend up to 12 days. At first, the symptoms are mild such as headache, fever, nausea, vomiting, etc but can quickly worsen. The latter symptoms include hallucinations, confusion, fatigue, loss of balance, seizures, and coma. After the symptoms commence the disease usually causes death in about 5 days ( can range from 1 – 12 days).
CAUSES :
Naegleria fowleri causes infection in humans when water contaminated with the amoeba enters the nasal passages. From there, it travels through the nasal cavity and directly impacts the brain. This can occur during activities such as swimming in freshwater bodies or untreated swimming pools, or cleansing the sinuses with untreated water.
DIAGNOSIS AND TREATMENTS :
The brain-eating amoeba poses significant diagnostic challenges, with approximately 75% of cases identified after the death of the victim. Due to the disease’s rarity and swift progression, established treatment protocols are lacking. Medical examiners generally commence diagnosis by analyzing Cerebrospinal fluid (CSF) or tissue samples.
CASES OF PAM :
The National Library of Medicine in the United States has undertaken significant studies aimed at diagnosing and developing treatments for Primary Amebic Meningoencephalitis (PAM) caused by Naegleria fowleri. An analysis of a fatal PAM case involving a 5-month-old infant, with no history of swimming, suggested that the amoeba may have entered through bathing water sourced from an artificial well. Similarly, in Australia, another fatal PAM case highlighted the presence of Naegleria fowleri in the household water supply. These instances underscore the potential for infection or disease transmission associated with bathing and washing activities.
PREVENTIVE MEASURES :
- Avoid swimming in freshwater sources like lakes, ponds, and rivers, especially during summer.
- Avoid swimming in untreated swimming pools.
- Use nose caps while jumping into warm and freshwater bodies.
- Avoid rinsing sinuses with direct water from pipes, lakes, ponds, rivers, or any other geothermal water sources.
- Use well-boiled water for cleansing sinuses.
- Rinse the nose with warm water immediately after swimming.
AWARENESS TO PUBLIC :
Significant measures should be taken up by the government, medical practitioners as well as citizens to educate society about this rare but deadly disease. It can easily survive in hot weather conditions which makes it highly spreadable among the population. However, the reported cases are fewer, its hard to conclude whether it’s a good thing or a bad thing as the unofficial and unreported numbers are unpredictable.
CONCLUSION :
Naegleria fowleri stands as a paradox—a pathogen that is easily encountered yet remarkably lethal. While literate populations can access information through articles, blogs, social media, and news, educating the less informed about the dangers posed by this amoeba is crucial. Once N. fowleri enters the human body via the nasal passage, its rapid progression can swiftly lead to fatality. Diagnosis, treatment, and cure are challenging due to the amoeba’s swift and elusive nature. Prevention and vigilant safeguarding are paramount, especially since initial symptoms may not initially raise significant concern. Government bodies and educational institutions should prioritize setting up awareness campaigns, as their outreach can effectively reach and inform a vast majority of the population about this grave threat.
