Is Naegleria fowleri an Emerging Parasite?

Abstract

Naegleria fowleri causes an uncommon but deadly disease called primary amoebic meningoencephalitis (PAM). There has been an increase of reported PAM cases, particularly since 2000. Although water is the dominant route of transmission of PAM, infection through soil/dust is a possible alternative route. We have observed differences in epidemiology between the southern US states and the Indian subcontinent (ISC). The patient age range is greater in ISC than the US, and there are more infections in ISC which are not water-associated. We show that PAM is under reported and argue that climate change will increase the incidence of PAM and the geographic range of N. fowleri will spread poleward.

A comparative ‘omics approach to candidate pathogenicity factor discovery in the brain-eating amoebaNaegleria fowleri

“…The reported incidence of infection is relatively low (Trabelsi et al, 2012); however, infection is likely more prevalent, particularly in developing countries with warm climates and inconsistent medical reporting. N. fowleri has been recently proposed as an emerging pathogen based on increased case reports in the past decade (MacIver et.al. 2019).…”

“…2019). With cases from temperate locations reported in recent years (Baral and Vaidya, 2018; Kemble et al, 2012), the threat of N. fowleri may be exacerbated by range expansion due to climate change (MacIver et.al. 2019), which has been associated with a rise in freshwater temperatures, an increase in aquatic recreational activities (Siddiqui and Khan, 2014), and extreme weather events.…”

“…2019), which has been associated with a rise in freshwater temperatures, an increase in aquatic recreational activities (Siddiqui and Khan, 2014), and extreme weather events. It is likely that we are still not fully aware of the global scale of N. fowleri infection (Maciver et al, 2019), or how infection may increase as climate change accelerates.…”

Ubiquitin-Like Modifiers: Emerging Regulators of Protozoan Parasites

“…Trichomoniasis, one of the most common sexually transmitted diseases, is caused by Trichomonas vaginalis , a protozoan parasite that remains understudied despite being globally widespread and linked to adverse pregnancy outcomes and increased HIV susceptibility [ 8 ]. Naegleria fowleri , the causative agent of a rare, but highly lethal, primary amoebic meningoencephalitis (PAM) with a mortality rate estimated at 95–97%, may be considered an emerging pathogen as there are indications of an upward trend in the number of PAM cases over the last two decades and an increasing favourability of environmental conditions for the growth of this parasite [ 9 ]. Lack of vaccines, limited chemotherapy options, and the emergence of drug-resistant parasites are the challenges posed by the majority of protozoan diseases.…”

An Optimized Most Probable Number (MPN) Method to Assess the Number of Thermophilic Free-Living Amoebae (FLA) in Water Samples

“…These low concentrations in environmental water often make it difficult to accurately count the FLA [16], regardless of the method that is used to concentrate the samples, either by centrifugation or filtration [17]. Because of the risk associated to the presence of N. fowleri (the presence of one single amoeba is enough to cause or start an infection) and the potential link between the concentration of N. fowleri and pathogenicity, it is important to obtain the most accurate count of this amoeba in water [18][19][20].…”