Transmission characteristics and prevention measures of Naegleria fowleri： a review / 上海预防医学

ABSTRACT

Objective To review the Naegleria fowleri and primary amoebic meningoencephalitis caused by the naegleria fowleri， so as to strengthen the public awareness of the disease and its prevention. Methods We reviewed the literatures and reports， and summarized the following information： epidemic status， life cycle and characteristics， environmental distribution and infection routes， pathogenesis and clinical manifestations， diagnosis and treatment， prevention and control measures. Results Primary amoeba meningoencephalitis is a water-borne disease caused by the Naegleria fowleri， which enters human body through the nose and arrives at the central nervous system through olfactory nerve， leading to hemorrhagic and necrotic meningitis. Although the disease is rare， it has a fatality rate of 95%. Most of the patients reported were healthy children or young adults who had nasal contact with water contaminated with Naegleria fowleri a week before symptoms appeared. At present， its pathology can be divided into contact mechanism and non-contact mechanism. In contact mechanism， the Naegleria fowleri relies on the phagocytosis of food cup on its surface and the release of cytolytic molecules that directly destroy host cells. In non-contact mechanism， the Naegleria fowleri has toxic effects by secreting proteins. The clinical symptoms are episodic， with an average time of five days from illness to death. At beginning， the symptoms may include headache， vomiting， fever and other influenza-like symptoms， followed by central nervous system symptoms， such as stiff neck， drowsiness， anorexia， fear and so on. Intravenous or intrathecal injection of amphotericin B is considered to be the basic treatment of this disease， which can be combined with other adjunct therapies such as ventricular shunt and cooling to reduce encephaledema. Conclusion Primary amoebic meningoencephalitis is a rare but highly fatal disease. We should strengthen the public awareness of the disease and its prevention， especially to avoid nasal contact with contaminated water. We should also strengthen scientific research， improve the level of diagnosis， and develop effective drugs to prevent the disease before it happens.