Mosquito viruses cause unpredictable outbreaks of disease. Recently, several unassigned viruses isolated from mosquitoes, including the Omono River virus (OmRV), were identified as totivirus-like viruses, with features similar to those of the Totiviridae family. Most reported members of this family infect fungi or protozoans and lack an extracellular life cycle stage. Here, we identified a new strain of OmRV and determined high-resolution structures for this virus using single-particle cryo-electron microscopy. The structures feature an unexpected protrusion at the five-fold vertex of the capsid. Disassociation of the protrusion could result in several conformational changes in the major capsid. All these structures, together with some biological results, suggest the protrusions’ associations with the extracellular transmission of OmRV.

Zika virus (ZIKV) is a mosquito-borne flavivirus isolated from the Zika forest of Uganda in 1947. 1 The clinical symptoms of ZIKV infection are mostly a mild and self-limited rash, arthralgia, and conjunctivitis in humans. More than 80% of ZIKV infections are asymptomatic. The ZIKV outbreaks in Brazil and French Polynesia indicate that the virus is linked to microcephaly and Guillain-Barré syndrome. 2,3 Meanwhile, severe eye damage in infants with microcephaly was associated with ZIKV infection. 4 However, it is still unclear whether the eye lesions are the result of microcephaly or directly ZIKV infection. 5 Therefore, we wondered whether ZIKV could be detected in conjunctival fluid. In this report, we describe the detection of ZIKV from conjunctival swab samples of laboratoryconfirmed ZIKV cases.Methods | Since February 12, 2016, 11 ZIKV infection cases (Chinese travelers) were imported from Venezuela in Guangdong, China (http://www.gdwst.gov.cn/a/yiqingxx). All the cases were confirmed to be ZIKV infection by real-time reversetranscription polymerase chain reaction (rRT-PCR) (DAAN gene, Guangzhou, China). The virus load was determined using a standard curve with serial dilutions of known plasmid concentrations. The serum and conjunctival swab samples were taken from 6 of 11 cases simultaneously. When evaluated by the institutional review board of the Guangdong province Center for Disease Control and Prevention, this activity was considered a component of the public health response to the imported Zika case in Guangdong; thus, it did not require review. However, each written epidemiology and sampling investigation report was approved by each case.Results | The results of rRT-PCR for ZIKV in serum of these 6 cases with estimated ZIKV RNA loads ranged from 9.9 × 10 2

In 2015, an unexpected multiple outbreak of dengue occurred in Guangdong, China. In total, 1,699 cases were reported, of which 1,627 cases were verified to have DENV infections by nucleic acid or NS1 protein, including 44 DENV-1, 1126 DENV-2, 18 DENV-3 and 6 DENV-4, and the other cases were confirmed by NS1 ELISA. Phylogenetic analyses of DENV-1 isolates identified two genotypes (I and V). The predominant DENV-2 outbreak isolates were the Cosmopolitan genotypes, which likely originated from Malaysia. The DENV-3 isolates were assigned into genotype I and genotype III. All 6 DENV-4 isolates from imported cases were likely originally from Cambodia, Thailand and the Philippines. The entomological surveillance showed a moderate risk for the BI index in Chaozhou and Foshan and a low risk in Guangzhou. The imported cases were mostly detected in Guangzhou and Foshan. Surprisingly, the most serious outbreak occurred in Chaozhou, but not in Guangzhou or Foshan. A combined analyses demonstrated the multiple geographical origins of this outbreak, and highlight the detection of suspected cases after the alerting of imported cases, early implementation of control policies and reinforce the vector surveillance strategies were the key points in the chain of prevention and control of dengue epidemics.

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