ABSTRACT
@#Abstract: Objective To investigate the prevalence of C580Y mutation of kelch13 gene in the imported P. falciparum cases in Wuhan City, China, and to provide a reference basis for the prevention and treatment of imported falciparum malaria. Methods From 2009 to 2015, blood samples were collected from returnees who infected with P. falciparum in endemic areas of Africa and Southeast Asia in Wuhan City. The P. falciparum DNA was extracted from the blood samples, and kelch13 gene was amplified by loop-mediated isothermal amplification (LAMP), and the distribution of C580Y mutation was analyzed. Results C580Y mutation was detected in 16 of the 208 cases tested by LAMP. No mutations were detected in 69 cases of imported falciparum malaria from Africa during 2009-2012, while 13 cases of the C580Y mutation were detected in 114 cases from 2013 to 2015, with a mutation rate of 11.4%. The mutation rate in South Africa, West Africa, and Central Africa was 12.5%, 9.6%, and 19.0%, respectively, with no mutations detected in cases from North Africa and East Africa. Among the 25 cases of falciparum malaria from Southeast Asia between 2009 and 2013, three cases were positive for the C580Y mutation, all from Myanmar, with a mutation rate of 14.3% (3/21) in Myanmar and 12.0% (3/25) in Southeast Asia. There was no significant difference in the mutation rate between Africa and Southeast Asia after 2013 (P>0.05). Conclusions Our findings highlight the varying degrees of C580Y mutations of kelch13 gene in imported P. falciparum cases in Wuhan and suggest the need for enhanced monitoring and evaluation of related resistance genes.
ABSTRACT
@#Abstract: Objective To analyze the emergency response and long-term intervention effects after the detection of infectious snails epidemic by loop-mediated isothermal amplification (LAMP) assays in Hannan District, Wuhan City, and to explore the application of LAMP in early surveillance and early-warning of schistosomiasis transmission. Methods Snails picked up by the risk monitoring system in Hannan District were examined by anatomical microscopy and LAMP technology to identify the schistosomiasis infection. Emergency response and intensive intervention were initiated in the environment where positive snails appeared, and the long-term effects were evaluated. Results In May 2018, the infectious snails were detected by LAMP technology in Hannan District, and the positive snails were located in Zhujiacha, Dongzhuang Village, Obstacles and weeds were removed and buried by machine in Zhujiacha. 12 700 m2 of snails were killed by drugs, and the mortality rate of snails was more than 80%; no new seropositive persons were found in the emergency examination within 500 m of the positive snail sites. 506 people were examined in Dong Zhuang Village at the end of the year, and 30 positive IHA cases were detected with a blood positive rate of 5.93%, no positive fecal test was found, and all positive blood test patients took preventive medication. The monitoring results of sentinel rats and wild feces were all negative. Health education was carried out, 7 warning signs were deployed and refreshed, and 500 publicity brochures were distributed. After nearly three years of intensified intervention and monitoring in the villages where the positive environment is located, and the density of snails on the stubborn snail has dropped from 0.094/frame to 0.027/frame, and the positive rate of blood test in Dongzhuang Village has steadily dropped from 5.93% to 3.74%. Conclusions The infected snails missed by microscopy were detected by LAMP in Hannan District, which created conditions for the rapid emergency treatment of environment and elimination of positive snail and improved the sensitivity of the surveillance and early warning system in transmission-interrupted areas.