Surveillance and response strategy in the malaria post-elimination stage: case study of Fujian province.

Malaria used to be a serious health problem in Fujian province in the past, but no local malaria transmission has been found since 2000. In order to eliminate the potential residual cases and prevent re-introduction of malaria so as to achieve the final goal of malaria elimination in Fujian province, various strategy and intervention approaches were tailored to the local settings. For instance, the monitoring of febrile patients by blood smear examinations and vector surveillance and control were strengthened in addition to the routine intervention in the mountainous area of Fujian province, where malaria was highly endemic and the mosquito Anopheles anthropophagus distributed with a high vectorial capacity. There were two local cases who got infected due to imported cases found in the building site of an expressway in 2004 and 2005, respective. All other imported malaria cases were detected during post-elimination stage through surveillance system. Based on results from post-transmission surveillance, malaria transmission has been interrupted in Fujian province for 13 years. Therefore, post-transmission surveillance and response is an important intervention to maintain the malaria elimination achievements in Fujian province.

[Genetic polymorphism of the gene encoding the apical membrane antigen-1 of Plasmodium falciparum].

OBJECTIVE: To study the genetic diversity of apical membrane antigen-1 gene from Plasmodium falciparum (PfAMA-1). METHODS: Filter paper blood samples were collected from 23 imported P. falciparum malaria patients who returned to Fujian Province from 2006 to 2012. Nested PCR were used to amplify the PfAMA-1 gene. The umplified fragments were sequenced, and analyzed by bioinformatic software. RESULTS: All 23 samples were amplified a 505 bp band. Thirty-two nucleotides were found to be variable, resulting in 18 haplotypes. Eight of these 18 halotypes were being reported here for the first time. The parasites collected from Africa showed the higher level of variability [haplotypes diversity (Hd)= 0.0985, nucleotide diversity (π)=0.0258] as compared to the isolates from Asia (Hd=0.909, π=0.0221). The average difference of dN-dS for all 23 PfAMA-1 sequences was 0.031±0.006. Sequence-based neutrality tests were not significant in Africa and Asia (P>0.05). The minimum number of recombination events (Rm) was 10, and the linkage disequilibrium index (R2) evidently declined with the increase of nucleotide distance. A molecular phylogenetic tree constructed using the neighbor-joining method showed that the 23 isolates were assigned to three clades (G1, G2 and G3). Most samples from Africa formed G1, and G3 contained most of Asian isolates. CONCLUSION: Plasmodium falciparum isolates from Africa show a higher genetic diversity than the isolates from Asia for PfAMA-1 gene.

[A case of imported schistosomiasis haematobia first reported in Fujian Province].

The first case of imported schistosomiasis haematobia in Fujian Province was detected and the patient was cured following treatment with praziquantel.

[Genotype I Japanese encephalitis virus is the main genotype in mosquito in Fujian province].

OBJECTIVE: To grasp the infection rate and genotypes of Japanese encephalitis virus (JEV) in mosquito in Fujian province. METHODS: Mosquito specimens in Sanming city, Jianyang city and Fuzhou city in Fujian province were collected in 2010. RT-PCR was used to detect the JEV sequence from the mosquitoes by specific primers. The sequence splicing and the differentiation analysis for nucleotides, deduced amino acid sequence and phylogenetic tree were performed by the software of ATGC, Clustal X (1.83), MegAlign, GeneDoc 3.2 and Mega (4.0). RESULTS: Totally 6987 mosquitoes were collected and main species was Culex tritaeniorhynchus and Anopheles sinensis. The infection rate of JEV in mosquitoes in Sanming, Jianyang and Fuzhou were 1.25%, 1.76% and 0.65%, respectively. One full genome in the positive specimens was sequenced. And further study showed that the positive JEV sequences belonged to genotype I. CONCLUSION: Genotype I Japanese encephalitis virus is the main genotype in mosquitos in Fujian province.