黄热病的再流行与世界卫生组织的消除黄热病流行战略

近年来,蚊虫传播的黄热病在非洲和南美洲地区大面积“再流行”,仅南美洲的巴西在一年时间就发现数千例黄热病确诊病例,黄热病已经在非洲和南美洲地区造成巨大的公共卫生负担。此外,在黄热病非流行国家和地区发现大量输入性病例,使得黄热病有可能在非洲和南美洲以外的地区成为“新发传染病”而在世界更大范围流行。为此,世界卫生组织制定了“消除黄热病流行（EYE）”战略,预计利用10年时间在黄热病流行地区接种13.8亿剂量黄热疫苗,以降低黄热病对国际公共卫生健康的危害。     

Rabies virus glycoprotein serology ELISA for measurement of neutralizing antibodies in sera of vaccinated human subjects

BackgroundVaccination provides protection against infection by inducing VNAs mainly against RABV surface GP. The measurement of VNAs to RABV is commonly used to assess the level of immunity in humans and animals after vaccination. A VNA titer of ≥ 0.5 IU/mL of sera indicates adequate response to vaccination. Here, we report the development and validation of a RABV GP serology ELISA kit for semi-quantitative measurement of VNA titers in sera of vaccinated human subjects.MethodsUsing a recombinant RABV GP expressed in mammalian cells as the capture antigen, the ELISA method was established using HuMAb NM57 reference initially and HRIG reference subsequently. The limit of detection (LOD), linear range, reproducibility, and precision of the method were examined. Specificity and sensitivity were established to assess the diagnostic accuracy.ResultsRABV GP for ELISA plate coating and optimal dilution of human serum sample was 1 µg/mL and 1:20, respectively. Multiple assays were carried out by different technicians at different laboratories for assay standardization. Using the HRIG reference, the LOD was found to be 0.02–0.06 IU/mL and the linear range was 0.2–10.0 IU/ mL. The inter-assay CVs were in the range of 6.60–10.79%, indicating the reproducibility. None of the 12 known negative human sera, tested positive by ELISA, highlighting the specificity. A total of 415 unknown positive human sera were double-blind tested by the RFFIT and ELISA. The VNA titer cut-off value of ELISA was set at 1.5 IU/mL to ensure no false-positive. The diagnostic specificity and sensitivity were 100% and 91.1%, respectively.ConclusionsThe validation data characterize this ELISA as a suitable method for semi-quantitative measurement of VNA titers in human serum samples to assess vaccination status. The ELISA kit can offer simplicity, speed, low cost and high throughput, making it a practical tool for monitoring the immune response following vaccination.     

The roles of prostaglandin E2 and D2 in lipopolysaccharide-mediated changes in sleep

When living organisms become sick as a result of a bacterial infection, a suite of brain-mediated responses occur, including fever, anorexia and sleepiness. Systemic administration of lipopolysaccharide (LPS), a common constituent of bacterial cell walls, increases body temperature and non-rapid eye movement (NREM) sleep in animals and induces the production of pro-inflammatory prostaglandins (PGs). PGE₂ is the principal mediator of fever, and both PGE₂ and PGD₂ regulate sleep–wake behavior. The extent to which PGE₂ and PGD₂ are involved in the effect of LPS on NREM sleep remains to be clarified. Therefore, we examined LPS-induced changes in body temperature and NREM sleep in mice with nervous system-specific knockouts (KO) for the PGE₂ receptors type EP₃ or EP₄, in mice with total body KO of microsomal PGE synthase-1 or the PGD₂ receptor type DP, and in mice treated with the cyclooxygenase (COX) inhibitor meloxicam. We observed that LPS-induced NREM sleep was slightly attenuated in mice lacking EP₄ receptors in the nervous system, but was not affected in any of the other KO mice or in mice pretreated with the COX inhibitor. These results suggest that the effect of LPS on NREM sleep is partially dependent on PGs and is likely mediated mainly by other pro-inflammatory substances. In addition, our data show that the main effect of LPS on body temperature is hypothermia in the absence of nervous system EP₃ receptors or in the presence of a COX inhibitor.     

Infección por el virus de la hepatitis C y nuevas estrategias de tratamiento

Hepatitis C is a major public health problem worldwide. This disease is caused by the hepatitis C virus, which is characterised by its genetic diversity. The infection is usually asymptomatic. However, between 60% and 80% of HCV-infected individuals will progress to chronic hepatitis, 20% to liver cirrhosis in the medium-to long-term and, each year, between 1% and 4% of these patients with cirrhosis will develop hepatocellular carcinoma (HCC). A Spanish consensus document has recently been drafted to diagnose hepatitis C in a single step, consisting of active investigation (antibodies and viremia) in a single sample, which according to the experts, would reduce the time to access treatment and avoid tracking losses. To definitively change the hepatitis C treatment paradigm, direct-acting antiviral drugs (DAAs) have been approved, whose development has been based on achieving cure rates close to 100% regardless of the genotype of the virus, ie, pangenotypes, with good tolerance and bioavailability. These drugs have constituted a real therapeutic revolution. Supplement information: This article is part of a supplement entitled «SEIMC External Quality Control Programme. Year 2016», which is sponsored by Roche, Vircell Microbiologists, Abbott Molecular and Francisco Soria Melguizo, S.A.© 2019 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosasy Microbiología Clínica. All rights reserved.     

Molecular characterization of the 17D-204 yellow fever vaccine

IntroductionThe worldwide use of yellow fever (YF) live attenuated vaccines came recently under close scrutiny as rare but serious adverse events have been reported. The population identified at major risk for these safety issues were extreme ages and immunocompromised subjects. Study NCT01426243 conducted by the French National Agency for AIDS research is an ongoing interventional study to evaluate the safety of the vaccine and the specific immune responses in HIV-infected patients following 17D-204 vaccination. As a preliminary study, we characterized the molecular diversity from E gene of the single 17D-204 vaccine batch used in this clinical study.Materials and methodsEight vials of lyophilized 17D-204 vaccine (Stamaril^®, Sanofi-Pasteur, Lyon, France) of the E5499 batch were reconstituted for viral quantification, cloning and sequencing of C/prM/E region.ResultsThe average rate of virions per vial was 8.68 ± 0.07 log₁₀ genome equivalents with a low coefficient of variation (0.81%). 246 sequences of the C/prM/E region (29–33 per vials) were generated and analyzed for the eight vials, 25 (10%) being defective and excluded from analyses. 95% of sequences had at least one nucleotide mutation. The mutations were observed on 662 variant sites distributed through all over the 1995 nucleotides sequence and were mainly non-synonymous (66%). Genome variability between vaccine vials was highly homogeneous with a nucleotide distance ranging from 0.29% to 0.41%. Average p-distances observed for each vial were also homogeneous, ranging from 0.15% to 0.31%.ConclusionThis study showed a homogenous YF virus RNA quantity in vaccine vials within a single lot and a low clonal diversity inter and intra vaccine vials. These results are consistent with a recent study showing that the main mechanism of attenuation resulted in the loss of diversity in the YF virus quasi-species.     

Vacunas contra el virus del papiloma humano

Persistent infection by human papilloma virus (HPV) is considered to be the main cause of cervical cancer and other ano-genital cancers. Of more than 30 genotypes able to infect the anogenital tract, it is estimated that, worldwide, HPV 16 and 18 cause 70% of cervical cancers and that HPV 6 and 11 cause more than 90% of genital warts. In the last few years, the morbidity and mortality and health costs associated with cervical cancer and its precursor lesions have stimulated intense research activity to achieve primary prevention of this disease through prophylactic vaccines.     

非鼻咽部T细胞淋巴瘤与EB病毒的相关性

目的：探讨EB病毒（EBV）感染与非鼻咽部T细胞淋巴瘤的关系。方法：用单克隆抗体UCHL-1、L26及EB病毒编码的潜在膜蛋白-1（LMP-1），免疫组化染色确定肿瘤的免疫表型及EB病毒转化蛋白的表达。采用原位杂交方法检测EBV编码的EBERs。结果：21例非鼻咽部T细胞淋巴瘤EBERs5例阳性的（23．8％），其中给内淋巴瘤3例，肺和胃肠淋巴瘤各1例。阳性细胞约占肿瘤细胞的10％～70％。5例EBERs阳性病例中仅1例表达LMP-1，为结内淋巴瘤。结论：非鼻咽部T细胞淋巴瘤可能与EBV的感染有关，LMP-1的阳性率较EBERs低。