Naegleria, Acanthamoeba, Vahlkampfia, and Hartmannella are free-living amoeba survive worldwide in different aquatic and soil habitat. Among the Naegleria spp, Naegleria fowleri is the only species pathogenic to humans which it causes primary amoebic meningoencephalitis (PAM). According to De Jonckheere JF (2011), there are at least 235 PAM cases reported worldwide. The disease seemed to be rare but deadly if occurred in person and only about 5% of patients so far survived. Almost 2/3 of cases of PAM was reported from the USA.(1)

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Who Is At Risk For Naegleria Infection?

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Who Is At Risk For Naegleria Infection?

Swimming ponds, artificial pool, streams, large lakes, polluted or contaminated rivers, hot springs and poorly maintained tap water were best culture medium or rich-habitat for N. fowleri. Chance of infections rarely occurs by accidental exposure, predominantly in children and young adults. As they are more dynamic in the water environment like diving, jumping into water and underwater swimming and are likely to come into direct contact with free-living amoebae in contaminated water. The organism enters the nasal cavity and migrates through the olfactory neuro-epithelium to the central nervous system and causes a fatal infection that exhibits symptoms similar to acute bacterial meningitis.

According to available literature from 1962 to 2018, 145 cases have been acknowledged in the USA which has occurred in all age groups. Among the cases, 121 i.e., 85% have occurred in children below 12 years and adolescents up to 66 years. Over three-quarters, (>75%) of infections have been in males. Infected people were often reported to have participated in water-related activities.(2)

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Inadequate Pathology Information Leads To Death

In several countries, young adults, children mostly expired due to the disease. No certain strong evidence could be produced. It is believed that neurological infections by these free-living amoebas are misdiagnosed as well as under-reported in several south East Asian countries. It is because of insufficient data regarding their pathology or due to a very low autopsy rate.

Climate And Weather Favors The Amoeba

Naegleria spp were most frequently isolated during the summer season particularly in the month of April to July. The onset of monsoon caused the rate reduction and the isolation frequency was high for water bodies with temperature ranging between 29–31°C. The incidence of the N. fowleri infection has been distinguished well in all continents, except in Antarctica. So far, seven types have been reported in Europe, three in American and two in Asian continents. Both type 3 and type 2 were common to Asian, American and European continents.

Identification Of Naegleria

Naegleria spp differences between inter-species intra-species are due to the sequence polymorphisms that occur at the internal transcribed spacer regions (ITS). The ITS region has also been used for the identification of the new Naegleria isolates at a molecular level. PCR based detection in order to confirm the Naegleria species that were present in our environment, a positive control N. fowleri cultures can be obtained from American Type Culture Collection (ATCC no. 30894).

Prevention Of Naegleria Infection

Many significant studies provide evidence of N. fowleri habitat in the natural and manmade water bodies. This free-living amoeba poses health risks to those people who use these aquatic systems for recreational activity and their day to day use. Considering the limited understanding of the ecology of free-living amoeba, practical measures have to be taken for prevention and control of infections particularly, N. fowleri. It includes better awareness of the disease within the medical community and educating the general public with the help of civic authorities. The best way to prevent amoeba growth is not to contaminate the water bodies with food as it enhances the growth of bacteria. Because Naegleria fowleri eats bacteria found in the sediment in lakes and rivers. Early diagnosis and new treatments including miltefosine and hypothermia might increase the chances for survival.(3)

Conclusion

Predominantly, children and young adults who are all active in the water environment like diving and swimming are likely to get this free-living amoebae infection. The chances of infection are higher in those people if their immunity are poor.

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Sheetal DeCaria MD

Written, Edited or Reviewed By:

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Last Modified On: June 12, 2019

This article does not provide medical advice. See disclaimer

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