Human angiostrongyliasis caused by Angiostrongylus cantonensis, a rat lungworm, has been reported globally. Human infections are acquired by ingestion of raw or undercooked snails or slugs, paratenic hosts such as prawns, or contaminated vegetables that contain the infective larvae of the worm. So far, at least 2827 cases of the disease have been documented worldwide. During the past few years, several outbreaks of human angiostrongyliasis have been reported in mainland China, Taiwan, and the USA. Additionally, sporadic cases in travellers who have returned from endemic areas have been reported. We review the clinical features, diagnosis, and treatment of human angiostrongyliasis, and describe the geographical distribution and prevalence of A cantonensis. Educating the public about the dangers of eating raw or undercooked intermediate and paratenic hosts in endemic areas is essential for the prevention and control of this foodborne zoonotic disease.

In China, the prevention and control of Zika virus disease has been a public health threat since the first imported case was reported in February 2016. To determine the vector competence of potential vector mosquito species, we experimentally infected Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus mosquitoes and determined infection rates, dissemination rates, and transmission rates. We found the highest vector competence for the imported Zika virus in Ae. aegypti mosquitoes, some susceptibility of Ae. albopictus mosquitoes, but no transmission ability for Cx. quinquefasciatus mosquitoes. Considering that, in China, Ae. albopictus mosquitoes are widely distributed but Ae. aegypti mosquito distribution is limited, Ae. albopictus mosquitoes are a potential primary vector for Zika virus and should be targeted in vector control strategies.

A novel mycovirus, termed Fusarium graminearum Hypovirus 2 (FgHV2/JS16), isolated from a plant pathogenic fungus, Fusarium graminearum strain JS16, was molecularly and biologically characterized. The genome of FgHV2/JS16 is 12,800 nucleotides (nts) long, excluding the poly (A) tail. This genome has only one large putative open reading frame, which encodes a polyprotein containing three normal functional domains, papain-like protease, RNA-dependent RNA polymerase, RNA helicase, and a novel domain with homologous bacterial SMC (structural maintenance of chromosomes) chromosome segregation proteins. A defective RNA segment that is 4553-nts long, excluding the poly (A) tail, was also detected in strain JS16. The polyprotein shared significant aa identities with Cryphonectria hypovirus 1 (CHV1) (16.8%) and CHV2 (16.2%). Phylogenetic analyses based on multiple alignments of the polyprotein clearly divided the members of Hypoviridae into two major groups, suggesting that FgHV2/JS16 was a novel hypovirus of a newly proposed genus-Alphahypovirus-composed of the members of Group 1, including CHV1, CHV2, FgHV1 and Sclerotinia sclerotiorum hypovirus 2. FgHV2/JS16 was shown to be associated with hypovirulence phenotypes according to comparisons of the biological properties shared between FgHV2/JS16-infected and FgHV2/JS16-free isogenic strains. Furthermore, we demonstrated that FgHV2/JS16 infection activated the RNA interference pathway in Fusarium graminearum by relative quantitative real time RT-PCR.

BackgroundAedes albopictus is a globally invasive mosquito and a major vector of arboviruses, including dengue, Zika and Chikungunya. Olfactory-related behaviors, particularly host-seeking, offer opportunities to disrupt the disease-transmission process. A better understanding of odorant receptors (ORs) may assist in explaining host selection and location, and contribute to novel strategy of vector control.MethodsBased on previous prediction of 158 putative odorant receptors by Ae. albopictus genome analysis, 29 AalORs were selected for tissue-specific expression profiles in the present study. AalOrco (AalOR7), AalOR10 and AalOR88, highly expressed in female olfactory tissues, were chosen for further structure predictions as well as functional validation including calcium imaging assay in human embryonic kidney (HEK293) cells and RNA interference assay in Ae. albopictus. We also conducted electrophysiological and behavioral assays in mosquitoes after RNA interference of the three genes to determine their roles in host-seeking.ResultsThe results support previous conclusions that individual conventional (ORXs) and Orco can form heteromeric complexes to recognize odorants and respond to components of human volatiles in HEK293 cells. The reduction of AalOrco transcript levels led to a significant decrease in host-seeking and confusion in host preference. In contrast, AalOR10 and AalOR88 knockdown mosquitoes showed no significant behavioral differences compared with controls. The functions of conventional ORs at least AalOR10 and AalOR88 are abolished with inhibited expression of the Orco gene orthologs, along with the concomitant relevant olfactory behavior.ConclusionsCombining structural and functional data, we conclude that the product of the Orco gene in this mosquito is crucial for transmitting olfactory signaling and conventional ORs contribute directly to odorant recognition. Our results provide insight into the linkage between odorant receptors and host-seeking in this important vector species.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1644-9) contains supplementary material, which is available to authorized users.

We describe here a double-stranded RNA mycovirus, termed Fusarium graminearum alternavirus 1 (FgAV1/AH11), from the isolate AH11 of the phytopathogenic fungus F. graminearum. Phylogenetic analysis showed that FgAV1/AH11 belongs to a newly proposed family, Alternaviridae. This is the first report of a mycovirus in the family Alternaviridae that infects F. graminearum.