Identification and significance of Naegleria fowleri isolated from the hot spring which related to the first primary amebic meningoencephalitis (PAM) patient in Taiwan

Tung, M.-C.^a, Hsu, B.-M.^b , Tao, C.-W.^c, Lin, W.-C.^g, Tsai, H.-F.^b, Ji, D.-D.^d, Shen, S.-M.^b, Chen, J.-S.^e, Shih, F.-C.^f, Huang, Y.-L.^h  

^a  Department of Surgery, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan 
^b  Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan 
^c  Section of Respiratory Therapy, Cheng Hsin General Hospital, Taipei, Taiwan 
^d  Research and Diagnostic Center, Centers for Disease Control, Taipei, Taiwan 
^e  Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan 
^f  Department of Environmental Engineering and Health, Yuanpei University of Science and Technology, Hsinchu, Taiwan 
^g  Department of Parasitology, National Cheng Kung University, Tainan, Taiwan 
^h  Department of Safety Health and Environmental Engineering, National Kaohsiung First University of Science and Technology, Kaohsiung, Taiwan 

Abstract

Naegleria fowleri can cause primary amoebic meningoencephalitis, a rapidly developing and highly lethal infectious disease. The first confirmed case of primary amoebic meningoencephalitis in Taiwan was reported in November 2011, in which the patient visited a thermal spring recreational area 1. week prior to hospitalisation. Water sampling was performed to verify the presence of Naegleria at the facility. According to our results, 32% and 20% of recreational water samples were contaminated with Naegleria spp. and Acanthamoeba spp., respectively. The genotypes of Naegleria identified at the hot spring included N. fowleri, Naegleria australiensis and Naegleria lovaniensis. Using PCR, it was determined that the strain of N. fowleri in one sample possessed the same genotype 2 as the clinical isolate. Thus, the thermal spring was suggested to be the likely source of infection. This is the first known instance of simultaneously isolating N. fowleri from both a patient as well as from a hot spring in Taiwan. Following this initial study, the pools at the thermal spring recreational area were drained, scrubbed and disinfected, and a follow-up study was performed 1. month later. Naegleria fowleri was not detected in follow-up testing; however, other Naegleria spp. were identified. We postulate that the biofilm in the waterlines may have provided a reservoir for free-living amoebae. The presence/absence of Acanthamoeba and Naegleria spp. did not differ significantly with any measured parameters related to water quality; however, a high percentage of the thermal water pool samples were contaminated with Naegleria or Acanthamoeba. Thus, amoebic contamination may present a serious threat to the health of humans who engage in leisure activities at thermal springs. © 2013 Australian Society for Parasitology Inc.

Author keywords

Acanthamoeba spp.; Biofilm; Genotype 2; Hot spring; Naegleria fowleri; Naegleria spp.; PAM patient; Waterlines

Indexed keywords

EMTREE drug terms: RNA 18S

GEOBASE Subject Index: bacterium; biofilm; encephalitis; genotype; health risk; protist; public health; thermal spring; water quality

EMTREE medical terms: Acanthamoeba; article; biofilm; controlled study; correlational study; follow up; genotype; Naegleria; Naegleria fowleri; naegleria lovaniensis; nonhuman; parasite identification; parasite isolation; polymerase chain reaction; primary amebic meningoencephalitis; RNA gene; species difference; strain identification; Taiwan; thermal spring; water contamination; water quality

Medline keywords: Acanthamoeba spp.; Biofilm; Genotype 2; Hot spring; Naegleria fowleri; Naegleria spp.; PAM patient; Waterlines
Medline is the source for the MeSH terms of this document.

MeSH: Animals; Central Nervous System Protozoal Infections; Genotype; Hot Springs; Humans; Naegleria fowleri; Taiwan; Water
Medline is the source for the MeSH terms of this document.

Regional Index: Taiwan

Species Index: Acanthamoeba; Naegleria; Naegleria australiensis; Naegleria fowleri; Naegleria lovaniensis

Chemicals and CAS Registry Numbers: Water, 059QF0KO0R