Evaluation of inapparent dengue infections during an outbreak in Southern China.

Few studies evaluating inapparent dengue virus (DENV) infections have been conducted in China. In 2013, a large outbreak of DENV occurred in the city of Zhongshan, located in Southern China, which provided an opportunity to assess the clinical spectrum of disease. During the outbreak, an investigation of 887 index case contacts was conducted to evaluate inapparent and symptomatic DENV infections. Post-outbreak, an additional 815 subjects from 4 towns with, and 350 subjects from 2 towns without reported autochthonous DENV transmission, as determined by clinical diagnosis, were evaluated for serological evidence of dengue IgG antibodies. Between July and November 2013, there were 19 imported and 809 autochthonous dengue cases reported in Zhongshan. Of 887 case contacts enrolled during the outbreak, 13 (1.5%) exhibited symptomatic DENV infection, while 28 (3.2%) were inapparent. The overall I:S ratio was 2.2:1 (95% CI: 1.1-4.2:1). Post-outbreak serological data showed that the proportion of DENV IgG antibody detection from the 4 towns with and the 2 towns without reported DENV transmission was 2.7% (95% CI: 1.6%-3.8%) and 0.6% (95% CI: 0-1.4%), respectively. The I:S ratio in the 3 towns where clinical dengue cases were predominately typed as DENV-1 was 11.0:1 (95% CI: 3.7-∞:1). The ratio in the town where DENV-3 was predominately typed was 1.0:1 (95% CI: 0.5-∞:1). In this cross-sectional study, data suggests a high I:S ratio during a documented outbreak in Zhongshan, Southern China. These results have important implications for dengue control, implying that inapparent cases might influence DENV transmission more than previously thought

Agonist of growth hormone–releasing hormone enhances retinal ganglion cell protection induced by macrophages after optic nerve injury

Optic neuropathies are leading causes of irreversible visual impairment and blindness, currently affecting more than 100 million people worldwide. Glaucoma is a group of optic neuropathies attributed to progressive degeneration of retinal ganglion cells (RGCs). We have previously demonstrated an increase in survival of RGCs by the activation of macrophages, whereas the inhibition of macrophages was involved in the alleviation on endotoxin-induced inflammation by antagonist of growth hormone–releasing hormone (GHRH). Herein, we hypothesized that GHRH receptor (GHRH-R) signaling could be involved in the survival of RGCs mediated by inflammation. We found the expression of GHRH-R in RGCs of adult rat retina. After optic nerve crush, subcutaneous application of GHRH agonist MR-409 or antagonist MIA-602 promoted the survival of RGCs. Both the GHRH agonist and antagonist increased the phosphorylation of Akt in the retina, but only agonist MR-409 promoted microglia activation in the retina. The antagonist MIA-602 reduced significantly the expression of inflammation-related genes Il1b, Il6, and Tnf. Moreover, agonist MR-409 further enhanced the promotion of RGC survival by lens injury or zymosan-induced macrophage activation, whereas antagonist MIA-602 attenuated the enhancement in RGC survival. Our findings reveal the protective effect of agonistic analogs of GHRH on RGCs in rats after optic nerve injury and its additive effect to macrophage activation, indicating a therapeutic potential of GHRH agonists for the protection of RGCs against optic neuropathies especially in glaucoma

Study design.

<p>Overview of the overall study design.</p

Demographic characteristics and relative risk analysis of 828 reported dengue cases in Zhongshan, Guangdong Province, China, 2013.

<p>Demographic characteristics and relative risk analysis of 828 reported dengue cases in Zhongshan, Guangdong Province, China, 2013.</p

The 2013 reported dengue cases, incidence rates, and DENV virus types of 6 select towns in Zhongshan, Guangdong province, China.

<p>The 2013 reported dengue cases, incidence rates, and DENV virus types of 6 select towns in Zhongshan, Guangdong province, China.</p

Case distribution.

<p>The distribution of dengue cases (n = 828) in Zhongshan, Guangdong Province, China, 2013.</p

Analysis of dengue infection and inapparent to symptomatic case ratios among cluster contacts by select characteristics in Zhongshan, Guangdong Province, China, 2013.

<p>NA: confidence interval not calculated</p><p>Analysis of dengue infection and inapparent to symptomatic case ratios among cluster contacts by select characteristics in Zhongshan, Guangdong Province, China, 2013.</p

Location and incident rates.

<p>The location of Zhongshan, Guangdong Province, China, and a map of the incidence rates of reported dengue cases by town, with the distribution of index cases in 2013.</p