Rubella virus replication and links to teratogenicity

Dynamics of Mpox infection in Nigeria: a systematic review and meta-analysis

The seasonal outbreaks of Mpox continue in most parts of West and Central Africa. In the past year, Nigeria had the highest number of reported cases. Here, we used the PRISMA guidelines to carry out a systematic review and meta-analysis of available evidence on Mpox in Nigeria to assess the prevalence, transmission pattern, diagnostic approach, and other associated factors useful for mitigating the transmission of the disease. All relevant observational studies in PubMed/MEDLINE, Embase, AJOL, Web of Science, Scopus and Google Scholar on Mpox in Nigeria were assessed within the last fifty years (1972 to 2022). In all, 92 relevant articles were retrieved, out of which 23 were included in the final qualitative analysis. Notably, most of the cases of Mpox in Nigeria were from the southern part of the country. Our findings showed a progressive spread from the southern to the northern region of the country. We identified the following factors as important in the transmission of Mpox in Nigeria; poverty, lack of basic healthcare facilities, and risk of exposure through unsafe sexual practices. Our findings reiterate the need to strengthen and expand existing efforts as well as establish robust multi-sectoral collaboration to understand the dynamics of Mpox Nigeria.

Prevalence and Risk Factors of Rubella and Cytomegalovirus Infections Among Pregnant Women in Makkah: Implications for Screening and Vaccination Programs

Introduction Contracting rubella virus or cytomegalovirus (CMV) while pregnant can lead to severe health issues for both the mother and the unborn child. This study aims to determine the prevalence of these infections in pregnant women and identify associated risk factors. Methods A total of 146 pregnant women consented to participate in this research. Data were collected through a detailed questionnaire and blood samples were obtained from each participant. Blood was drawn into vacutainer tubes, and plasma was separated and stored at -20°C for analysis. We utilized specific enzyme-linked immunosorbent assays (ELISA) for immunoglobulin G (IgG) and Immunoglobulin M (IgM) to detect antibodies against rubella and CMV in the plasma samples. Results The study revealed that the prevalence rates of IgG antibodies for rubella and CMV were 68.5% and 97.3%, respectively. No samples tested positive for IgM antibodies for either disease. A significant relationship was found between chronic rubella infection and women aged 26 to 35 years (p < 0.05). A significant association was also observed between chronic CMV infection and women with lower income (p < 0.05). Conclusion This study confirms the widespread presence of chronic rubella and CMV infections among pregnant women in Makkah. The findings highlight the impact of socioeconomic factors on infection rates and underscore the importance of implementing vaccination programs to mitigate the severity of these infections in pregnant women and protect fetal health.

Profile of cardiac lesions among laboratory confirmed congenital rubella syndrome (CRS) infants: a nationwide sentinel surveillance, India, 2016-22

Background

The phenotypical profile of cardiovascular malformations in patients with congenital rubella syndrome (CRS) is varied. We aimed to describe the profile of cardiac defects among CRS patients detected in the sentinel CRS surveillance in India during 2016-22.

Methods

Sentinel sites enrolled infants with suspected CRS based on presence of cardiac defects, hearing impairment, eye signs, or maternal history of febrile rash illness. Suspected CRS cases underwent detailed systemic examination, including echocardiography and serological investigation for rubella. Cardiac defects were categorized as 'Simple' or 'Complex' as per the National Heart, Lung, and Blood Institute classification. We compared the distribution of cardiac defects among laboratory confirmed CRS cases and seronegative discarded cases.

Findings

Of the 4578 suspected CRS cases enrolled by 14 sites, 558 (12.2%) were laboratory confirmed. 419 (75.1%) laboratory confirmed cases had structural heart defects (simple defects: n = 273, 65.2%, complex defects: n = 144, 34.4%), with ventricular septal defect (42.7%), atrial septal defect (39.4%), patent ductus arteriosus (36.5%), and tetralogy of Fallot as the commonest defects (4.5%). Laboratory confirmed CRS cases had higher odds of left to right shunt lesions (OR = 1.58, 95% CI: 1.15-2.17). This was mainly on account of a significant association of PDA with CRS (OR = 1.77, 95% CI: 1.42-2.21). Mortality was higher among CRS patients with complex heart defects (HR = 2.04, 95% CI: 1.26-3.30).

Interpretation

Three-fourths of the laboratory confirmed CRS cases had structural heart defects. CRS patients with complex cardiac defects had higher mortality. Detecting CRS infection early and providing timely intervention for cardiovascular defects is critical for the management of CRS patients.

Funding

Ministry of Health and Family Welfare, Govt of India, through Gavi, the Vaccine Alliance.

Evaluation of the rubella surveillance system in South Africa, 2016-2018: A cross-sectional study

BACKGROUND

Rubella is a leading vaccine-preventable cause of birth defects. We conducted this study to evaluate the rubella surveillance system in South Africa from 2016 to 2018. The rubella surveillance system had not been evaluated since its inception; therefore, a formal evaluation is necessary to assess key attributes and to ascertain the extent to which the system achieves its objectives.

METHODS

We conducted a cross-sectional study to assess the usefulness, simplicity, positive predictive value, timeliness, and data quality of the rubella surveillance system from 2016 to 2018. We reviewed retrospective rubella surveillance data and conducted a survey with key stakeholders of the system. We compiled a summary report from the survey and calculated the annualized detection rate of rubella and non-rubella febrile rash, positive predictive value, the proportion of complete records, and timeliness between the surveillance steps. We compared our results with recommended performance indicators from the 2015 revised World Health Organization African regional guidelines for measles and rubella surveillance.

RESULTS

The rubella surveillance system was useful but weak in terms of simplicity. The annualized detection rate of rubella febrile rash was 1.5 per 100,000 populations in 2016, 4.4 in 2017, and 2.1 in 2018. The positive predictive value was 29.1% in 2016, 40.9% in 2017, and 32.9% in 2018. The system did not meet the timeliness goal in the health facility component but met this goal in the laboratory component. The system had poor data quality, particularly in the health facility component.

CONCLUSIONS

The rubella surveillance system was useful, although it was not simple to use and had low PPV, poor timeliness, and poor data quality. Efforts should be made to improve the system's simplicity, PPV, timeliness, and data quality at the facility level.

Epidemiological Pattern of Rubella in Africa: A Review of Selected Sub-Saharan African Countries

Rubella, (German measles) is vaccine-preventable and a viral disease of public health importance. It presents with mild febrile rash illness, attendant congenital sequel and foetal death. This paper seeks to do a review of the epidemiology of rubella in selected sub-Saharan African countries. This is a review of literatures involving data triangulation of rubella surveillance data. World Health Organization (WHO)rubella surveillance data (2015-2018) available online was used to present the seasonal/time-variation. Data was extracted from the site into Microsoft Excel over three months period (October-December, 2018). Univariate data analysis was done using SPSS-23 and data were presented with appropriate tables and charts to show the trend. Epidemiologic findings showed that periodicity of rubella varies across countries in Africa with seasonal variation across the four sub-regions. In the West Africa sub-region, sharp increases occurred in reported cases in January with peaks in March-April. In Nigeria, a West African country, available data showed that seasonal peak occurs in the first four months (Jan-April) of the year with most of the burden among those below fifteen years of age, affects both sexes and incidence cuts across both rural and urban areas. However, in the Central sub-region, spikes generally occur between February and March with troughs in September to November. In the East sub-region, dual peaks occur in March-April and in September-October; in the South sub-region, unique annual seasonality with few cases reported in January-June each year. The peak incidence of rubella has been observed to be a function of the seasonal peaks/variation in Africa. Therefore, the knowledge of this seasonal variation can be leveraged upon by Governments to control the disease through scaling up of awareness creation and surveillance during the identified peaks and beyond.

Molecular and Structural Insights into the Life Cycle of Rubella Virus

Rubella virus (RUBV), a rubivirus, is an airborne human pathogen that generally causes mild measles-like symptoms in children or adults. However, RUBV infection of pregnant women can result in miscarriage or congenital rubella syndrome (CRS), a collection of long-term birth defects including incomplete organ development and mental retardation. Worldwide vaccination campaigns have significantly reduced the number of RUBV infections, but RUBV continues to be a problem in countries with low vaccination coverage. Further, the recent discovery of pathogenic rubiviruses in other mammals emphasizes the spillover potential of rubella-related viruses to humans. In the last decade, our understanding of RUBV has been significantly increased by virological, biochemical, and structural studies, providing a platform to begin understanding the life cycle of RUBV at the molecular level. This review concentrates on recent work on RUBV, focusing on the virion, its structural components, and its entry, fusion, and assembly mechanisms. Important features of RUBV are compared with those of viruses from other families. We also use comparative genomics, manual curation, and protein homology modeling to highlight distinct features of RUBV that are evolutionarily conserved in the non-human rubiviruses. Since rubella-like viruses may potentially have higher pathogenicity and transmissibility to humans, we also propose a framework for utilizing RUBV as a model to study its more pathogenic cousins.

Prenatal cytomegalovirus, rubella, and Zika virus infections associated with developmental disabilities: past, present, and future

Prenatal infections have long been recognized as important, preventable causes of developmental disabilities. The list of pathogens that are recognized to have deleterious effects on fetal brain development continues to grow, most recently with the association between Zika virus (ZIKV) and microcephaly. To answer clinical questions in real time about the impact of a novel infection on developmental disabilities, an historical framework is key. The lessons learned from three historically important pathogens: rubella, cytomegalovirus, and ZIKV, and how these lessons are useful to approach emerging congenital infections are discussed in this review. Congenital infections are preventable causes of developmental disabilities and several public health approaches may be used to prevent prenatal infection. When they cannot be prevented, the sequelae of prenatal infection may be treatable. WHAT THIS PAPER ADDS: The list of prenatal infections associated with developmental disabilities continues to increase. Lessons learned from rubella, cytomegalovirus, and Zika virus have implications for new pathogens. Severity of illness in the mother does not correlate with severity of sequelae in the infant.

Polymerase Chain Reaction and Serology Test to Detect Rubella Virus in Congenital Rubella Syndrome Patients with Hearing Loss

Rubella infections in pregnant women, especially during the first trimester, often lead to manifest as congenital rubella syndrome (CRS). This syndrome consists of several inherited disorders such as deafness, cataracts, and cardiac abnormalities. Deafness is the most common manifestation of CRS, 70-90% of all cases with deafness type are sensory neural deafness. The mechanism of hearing loss due to rubella virus is caused by hypoxia resulting from endothelial vascular damage in cochlea, followed by cell death in the organ of Corti and stria vascularis.Cochlea’s stria damage makes alterations in the composition of endolymph. This study aimed to confirm rubella infection using PCR and serological tests in patients with CRS who were clinically deaf. A suspected CRS reported was a 2-month-old patient with an unclear response to surround sound. The patient had been already diagnosed with congenital cataracts before. Prenatal, perinatal and postnatal history was evaluated. Hearing screening was done by OAE (Biological), and AABR (Beraphone). Anti-rubella IgM and IgG was obtained from blood serum. PCR was carried out from a throat swab and the eye-lens specimen. OAE and AABR results ‘refer’ to both sides of the ear indicated a sensorineural hearing loss. The serological examination of IgM was positive with an index of 15.00 and IgG rubella positive with a titer> 500 IU / ml. Positive results from the rubella virus were identified from the throat swab and lens specimens using the PCR method. Detection of rubella virus in CRS sufferers with clinical deafness of both ears gives positive results using PCR and serology methods. In the future PCR can be potential for prenatal diagnosis of rubella virus aimed at the provision of early prevention.

Molecular Application of Aptamers in the Diagnosis and Treatment of Cancer and Communicable Diseases

Cancer and infectious diseases such as Ebola, HIV, tuberculosis, Zika, hepatitis, measles and human schistosomiasis are serious global health hazards. The increasing annual morbidities and mortalities of these diseases have been blamed on drug resistance and the inefficacy of available diagnostic tools, particularly those which are immunologically-based. Antibody-based tools rely solely on antibody production for diagnosis and for this reason they are the major cause of diagnostic delays. Unfortunately, the control of these diseases depends on early detection and administration of effective treatment therefore any diagnostic delay is a huge challenge to curbing these diseases. Hence, there is a need for alternative diagnostic tools, discovery and development of novel therapeutic agents. Studies have demonstrated that aptamers could potentially offer one of the best solutions to these problems. Aptamers are short sequences of either DNA or RNA molecules, which are identified in vitro through a SELEX process. They are sensitive and bind specifically to target molecules. Their promising features suggest they may serve as better diagnostic agents and can be used as drug carriers for therapeutic purposes. In this article, we review the applications of aptamers in the theranostics of cancer and some infectious diseases.

Alterations in Cell Mechanics by Actin Cytoskeletal Changes Correlate with Strain-Specific Rubella Virus Phenotypes for Cell Migration and Induction of Apoptosis

The cellular cytoskeleton is central for key cellular functions, and as such is a marker for diseased and infected cell states. Here we analyzed infection with rubella virus (RV) strains with respect to phenotypes in cellular mechanical properties, cell movement, and viral cytopathogenicity. Real-time deformability cytometry (RT-DC), as a high-throughput platform for the assessment of cell mechanics, revealed a correlation of an increase in cortical filamentous-actin (F-actin) with a higher cellular stiffness. The additional reduction of stress fibers noted for only some RV strains as the most severe actin rearrangement lowered cell stiffness. Furthermore, a reduced collective and single cell migration speed in a wound healing assay was detected in addition to severe changes in cell morphology. The latter was followed by activation of caspase 3/7 as a sign for induction of apoptosis. Our study emphasizes RT-DC technology as a sensitive means to characterize viral cell populations and to implicate alterations of cell mechanical properties with cell functions. These interdependent events are not only promising options to elucidate viral spread and to understand viral pathologies within the infected host. They also contribute to any diseased cell state, as exemplified by RV as a representative agent for cytoskeletal alterations involved in a cytopathological outcome.

Computational identification of mutually homologous Zika virus miRNAs that target microcephaly genes

Background Zika virus (ZIKV) has been associated with a variety of neuropathologies, including microcephaly. We hypothesize that ZIKV genes activate host microRNAs (miRNAs) causing dysfunctional development of human fetal brains.

Objectives/methods A bioinformatics search for miRNA genome-wide binding sites in the prototypic ZIKV (strain MR766) was undertaken to hunt for miRNAs with significant similarities with MCPH genetic sequences responsible for inducing MCHP in human fetal brains.

Results Six ZIKV miRNAs were found to share mutual homology with 12 MCPH genetic sequences responsible for inducing MCPH. Noteworthy was miR-1304, which expressed 100% identity to six different MCPH genes.

Conclusions We suggest that following infection of fetal neurons ZIKV may modulate the action of various miRNAs, and miR-1304 in particular, resulting in microcephaly.

Progress towards rubella elimination after implementation of rubella immunization for over 20 years in Shandong province, China

The rubella vaccine has been included in the immunization program in Shandong province of China since 1995. Here we observed the rubella vaccine coverage, epidemiology, serosurvey, and virological surveillance data, in order to identify the challenges impeding the progress towards to its elimination following the implementation of rubella immunization over a 21-year period in Shandong province. We first noted that the annual increase in vaccination coverage resulted in decreased rate of rubella incidence, which was maintained at a low level. Second, the average age of rubella patients had shifted to the 15-29-year age group, making this group the main population affected by the rubella virus (RV). Third, more than 90% of the study population were immune to rubella. However, the positive rate of rubella IgG in some cities was relatively lower indicating that an insufficient proportion of individuals had been vaccinated. Finally, the transmission of the genotype 1E RV was gradually interrupted due to the implementation of rubella vaccination. Unfortunately, the endemicity of the imported genotype 2B RV was established due to the pockets with unvaccinated people. Therefore, comprehensive vaccination coverage of the population, combined with high quality monitoring of rubella, is necessary to achieve the rubella elimination goal.

Infection of iPSC Lines with Miscarriage-Associated Coxsackievirus and Measles Virus and Teratogenic Rubella Virus as a Model for Viral Impairment of Early Human Embryogenesis

Human induced pluripotent stem cell (iPSC) lines are a promising model for the early phase of human embryonic development. Here, their contribution to the still incompletely understood pathogenesis of congenital virus infections was evaluated. The infection of iPSC lines with miscarriage-associated coxsackievirus B3 (CVB3) and measles virus (MV) was compared to the efficient teratogen rubella virus (RV). While CVB3 and MV were found to be cytopathogenic on iPSC lines, RV replicated without impairment of iPSC colony morphology and integrity. This so far outstanding course of infection enabled maintenance of RV-infected iPSC cultures over several passages and their subsequent differentiation to ectoderm, endoderm, and mesoderm. A modification of the metabolic profile of infected iPSC lines was the only common aspect for all three viruses. This study points toward two important aspects. First, iPSC lines represent a suitable cell culture model for early embryonic virus infection. Second, metabolic activity represents an important means for evaluation of pathogen-associated alterations in iPSC lines.

How to determine protective immunity in the post-vaccine era

The ability to determine an individual's susceptibility to infection relies heavily on the assay used, and the ability to correlate results of the assay to a clinical interpretation. Current rubella immunity screening methods identify total rubella IgG antibodies circulating in the serum, however both humoral and cell mediated immune responses have been shown to contribute to protection from infection. Therefore, antibody screening assays may under-estimate immunity in some populations. In fact, waning antibody titers over time in a large prenatal population were recently documented in North America, and the trend has been echoed in other countries that have achieved elimination through universal rubella vaccination. Despite decreasing antibody titers, the number of acute rubella cases has not increased in these populations, suggesting that the lower antibody levels may still be protective. Based on the changing epidemiology in universally vaccinated populations, it may be time to reassess the level of antibody that indicates immunity to rubella infection.

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Introducción. El virus del Zika (ZIKV) es un flavivirus con envoltura, transmitido a los seres humanos principalmente por el vector Aedes aegypti. La infección por ZIKV se ha asociado con un gran neurotropismo y con efectos neuropáticos, como el síndrome de Guillain-Barré en el adulto y la microcefalia fetal y posnatal, así como con un síndrome de infección congénita similar al producido por el virus de la rubéola (RV).Objetivo. Comparar las estructuras moleculares de la proteína de envoltura E del virus del Zika (E-ZIKV) y de la E1 del virus de la rubéola (E1-RV), y plantear posibles implicaciones en el neurotropismo y en las alteraciones del sistema nervioso asociadas con el ZIKV.Materiales y métodos. La secuencia de aminoácidos de la proteína E-ZIKV (PDB: 5iZ7) se alineó con la de la glucopreteína E1 del virus de la rubéola (PDB: 4ADG). Los elementos de la estructura secundaria se determinaron usando los programas Vector NTI Advance®, DSSP y POSA, así como herramientas de gestión de datos (AlignX®). Uno de los criterios principales de comparación y alineación fue la asignación de residuos estructuralmente equivalentes, con más de 70 % de identidad.Resultados. La organización estructural de la proteína E-ZIKV (PDB: 5iZ7) fue similar a la de E1-RV (PDB: 4ADG) (70 a 80 % de identidad), y se observó una correspondencia con la estructura definida para las glucoproteínas de fusión de membrana de clase II de los virus con envoltura. E-ZIKV y E1-RV exhibieron elementos estructurales de fusión muy conservados en la región distal del dominio II, asociados con la unión a los receptores celulares de entrada del virus de la rubéola (glucoproteína de mielina del oligodendrocito, Myelin Oligodendrocyte Glycoprotein, MOG), y con los receptores celulares Axl del ZIKV y de otros flavivirus.Conclusión. La comparación de las proteínas E-ZIKV y E1-RV es un paso necesario hacia la definición de otros factores moleculares determinantes del neurotropismo y la patogenia del ZIKV, el cual puede contribuir a generar estrategias de diagnóstico, prevención y tratamiento de las complicaciones neurológicas inducidas por el ZIKV.

Antiviral activity of hemolymph of Podalia against rubella virus

Many active principles produced by animals, plants and microorganisms have been employed in the development of new drugs for the treatment of human diseases. Among animals known to produce pharmacologically active molecules that interfere in human cell physiology. Rubella virus (genus Rubivirus, family Togaviridae) is a single stranded RNA virus of positive genome polarity. Rubella virus infection of susceptible women during the first trimester of pregnancy often results in long-term virus persistence in the fetus causing multiple organ abnormalities. Potent antiviral activity against rubella virus (RV) has been observed in the hemolymph of Podalia sp. (Lepidoptera: Megalopygidae). This study evaluated the effect of hemolymph on RV infected Statens Serum Institute Rabbit Cornea (SIRC) cells. Results of cell viability and cell proliferation assays indicated that hemolymph was not toxic to cultured SIRC cells. Viral binding assay, antiviral assay, PCR, real-time PCR, and transmission electron microscopy were used to demonstrate that hemolymph in post-treatment could inhibit the production of infectious RV particles. Specifically, hemolymph was found to inhibit RV adsorption to the SIRC cells.

Rubella immune status of neonates - a window towards seroprevalence among childbearing women

BACKGROUND

When contracted in pregnancy, rubella may cause serious chronic infection of the fetus and development of Congenital Rubella Syndrome. Despite widespread application of rubella vaccination, periodical outbreaks are still being reported worldwide. The aim of this study was to determine rubella seroprevalence and antibody levels in neonates in Serbia as a proxy of maternal serostatus.

METHODS

ELISA based serological testing for rubella was done in 599 neonates treated at the Institute of Neonatology in Belgrade, from January 2010 to December 2011. All individuals with rubella IgG concentration ≥10 IU/ml were considered seropositive for rubella.

RESULTS

The mean age of enrolled neonates was 18 ± 6 days. The overall seroprevalence of rubella IgG antibodies among the tested neonates was 540/599(90.2 %, 95 % CI: 87.5-92.3). Seropositivity rate among sera of the neonates enrolled in 2010 was significantly higher than those collected in 2011 (p < 0.0001). There was no difference in average maternal age, gestational age or frequency of receiving blood products among the two study years. Significant high seropositivity rate was observed among neonates from mother aged >30 as compared to those from mothers aged <20 years (p = 0.02). Significant difference was also found between average IgG titers in the two study years (79 IU/mL in 2010 vs. 46 IU/mL in 2011, p < 0.0001).

CONCLUSION

We report on high rubella seroprevalence among newborns in Serbia, as a proxy of rubella serostatus of childbearing aged women. Notably, declining trend of rubella antibodies toward diminishing titers suggest the importance of sustained rubella serosurvey and antenatal screening at the national level.

Standardization of Assays That Detect Anti-Rubella Virus IgG Antibodies

Rubella virus usually causes a mild infection in humans but can cause congenital rubella syndrome (CRS). Vaccination programs have significantly decreased primary rubella virus infection and CRS; however, vaccinated individuals usually have lower levels of rubella virus IgG than those with natural infections. Rubella virus IgG is quantified with enzyme immunoassays that have been calibrated against the World Health Organization (WHO) international standard and report results in international units per milliliter. It is recognized that the results reported by these assays are not standardized. This investigation into the reasons for the lack of standardization found that the current WHO international standard (RUB-1-94) fails by three key metrological principles. The standard is not a pure analyte but is composed of pooled human immunoglobulin. It was not calibrated by certified reference methods; rather, superseded tests were used. Finally, no measurement uncertainty estimations have been provided. There is an analytical and clinical consequence to the lack of standardization of rubella virus IgG assays, which leads to misinterpretation of results. The current approach to standardization of rubella virus IgG assays has not achieved the desired results. A new approach is required.

Zika Fetal Neuropathogenesis: Etiology of a Viral Syndrome

The ongoing Zika virus epidemic in the Americas and the observed association with both fetal abnormalities (primary microcephaly) and adult autoimmune pathology (Guillain-Barré syndrome) has brought attention to this neglected pathogen. While initial case studies generated significant interest in the Zika virus outbreak, larger prospective epidemiology and basic virology studies examining the mechanisms of Zika viral infection and associated pathophysiology are only now starting to be published. In this review, we analyze Zika fetal neuropathogenesis from a comparative pathology perspective, using the historic metaphor of "TORCH" viral pathogenesis to provide context. By drawing parallels to other viral infections of the fetus, we identify common themes and mechanisms that may illuminate the observed pathology. The existing data on the susceptibility of various cells to both Zika and other flavivirus infections are summarized. Finally, we highlight relevant aspects of the known molecular mechanisms of flavivirus replication.

Calcium-Dependent Rubella Virus Fusion Occurs in Early Endosomes

The E1 membrane protein of rubella virus (RuV) is a class II membrane fusion protein structurally related to the fusion proteins of the alphaviruses, flaviviruses, and phleboviruses. Virus entry is mediated by a low pH-dependent fusion reaction through E1's insertion into the cell membrane and refolding to a stable homotrimer. Unlike the other described class II proteins, RuV E1 contains 2 fusion loops, which complex a metal ion between them by interactions with residues N88 and D136. Insertion of the E1 protein into the target membrane, fusion, and infection require calcium and are blocked by alanine substitution of N88 or D136. Here we addressed the requirements of E1 for calcium binding and the intracellular location of the calcium requirement during virus entry. Our results demonstrated that N88 and D136 are optimally configured to support RuV fusion and are strongly selected for during the virus life cycle. While E1 has some similarities with cellular proteins that bind calcium and anionic lipids, RuV binding to the membrane was independent of anionic lipids. Virus fusion occurred within early endosomes, and chelation of intracellular calcium showed that calcium within the early endosome was required for virus fusion and infection. Calcium triggered the reversible insertion of E1 into the target membrane at neutral pH, but E1 homotrimer formation and fusion required a low pH. Thus, RuV E1, unlike other known class II fusion proteins, has distinct triggers for membrane insertion and fusion protein refolding mediated, respectively, by endosomal calcium and low pH.

IMPORTANCE

Rubella virus causes a mild disease of childhood, but infection of pregnant women frequently results in miscarriage or severe birth defects. In spite of an effective vaccine, RuV disease remains a serious problem in many developing countries. RuV infection of host cells involves endocytic uptake and low pH-triggered membrane fusion and is unusual in its requirement for calcium binding by the membrane fusion protein. Here we addressed the mechanism of the calcium requirement and the required location of calcium during virus entry. Both calcium and low pH were essential during the virus fusion reaction, which was shown to occur in the early endosome compartment.

Infectivity of Immature Neurons to Zika Virus: A Link to Congenital Zika Syndrome

BACKGROUND

Epidemiological data strongly suggest that microcephaly cases in Brazil are associated with the ongoing epidemic of Zika virus (ZIKV). In order to further solidify the possible link, we investigated the infectivity of ZIKV using various neuroblastoma (NB) cell lines.

METHODS

Six undifferentiated, two terminally differentiated and two retinoic acid (RA) -induced, partially differentiated cell lines were exposed to ZIKV strain PRVABC59, which is genetically similar to the French Polynesia strain, with 97-100% genetic homology to the current ZIKV strain found in Brazil. All infections were confirmed by real-time PCR (RT-qPCR), immunofluorescence assay (IFA) probing with anti-flavivirus E antibody, and evaluation of cytopathic effects.

FINDINGS

ZIKV infected all six undifferentiated NB cell lines. In five out of six NB cell lines, between 90 and 70% cells were positive by IFA whereas for one cell line, CCL-127, ~80% of cells were positive for ZIKV as determined by IFA but showed persistent infection. Two differentiated cell lines, JFEN and T-268, were highly resistant to ZIKV with <1% of the cells being susceptible, as determined by IFA and confirmed by qRT-PCR. Two retinoic acid (RA)-induced NB partially differentiated cell lines showed no difference in permissiveness as compared to their undifferentiated mother cell lines.

INTERPRETATION

These findings strengthen the reported association between high incidences of microcephaly and ZIKV infection in newborns in Brazil. Our results suggest that the undifferentiated neurons are highly permissive to ZIKV infection, as one would expect during the early stages of neurogenesis in fetal brains; whereas differentiated neurons, representative of adult brain neurons, are relatively resistant to the virus, which explains the rare occurrence of neurological complications in adults infected with ZIKV. Our studies confirm the neurotropism of the ZIKV strain closely related to the current epidemic in Latin America.

Epidemiological Evaluation of Rubella Virus Infection among Pregnant Women in Ibadan, Nigeria

Rubella is a vaccine-preventable, mild rash-inducing viral disease with complications that include a spectrum of birth defects in the developing fetus, especially if the infection is acquired in the early months of pregnancy. Consequently, the primary objective of global rubella control programs is prevention of congenital rubella infection and associated birth defects. Despite the availability of safe and effective vaccines, and the elimination of the rubella virus in many developed countries, substantial commitment to rubella control has not been demonstrated in developing countries. This study appraises immunity to rubella, and consequently makes appropriate recommendations aimed at facilitating effective control. A cross-sectional sero-surveillance study was carried out among defined 272 consenting ante-natal clinic attendees in south-western, Nigeria. Prevalence rates of 91.54% and 1.84% were recorded for the anti-rubella virus (anti-RV) IgG and IgM, respectively. Also, 90.7% and 92.3% of the women aged ≤30 years and >30 years, respectively, had detectable anti-RV IgG. No significant association (p = 0.94) was recorded between anti-RV IgG detection and age of the women. Previous exposure and susceptibility of significant fraction of the population to rubella infection were confirmed. Considerable political commitment and promotion of free rubella immunization specifically for women with childbearing potential were recommended.

Gene expression profiling of rubella virus infected primary endothelial cells of fetal and adult origin

BACKGROUND

Rubella virus (RV) infection is usually a mild illness in children and adults. However, maternal infection during the first trimester of pregnancy can lead to congenital rubella syndrome (CRS) in the infant. Fetuses with CRS show damage to the endothelium of the heart and blood vessels; thus, it has been speculated that the clinical manifestations associated with CRS may be a result of endothelial cells persistently infected with RV. Here, we compared the effects of RV infection on gene expression in primary endothelial cells of fetal (HUVEC) and of adult (HSaVEC) origin by transcriptional profiling.

RESULTS

More than 75 % of the genes differentially regulated following RV infection were identical in both cell types. Gene Ontology (GO) analysis of these commonly regulated genes showed an enrichment of terms involved in cytokine production and cytokine regulation. Increased accumulation of inflammatory cytokines following RV infection was verified by protein microarray. Interestingly, the chemokine CCL14, which is implicated in supporting embryo implantation at the fetal-maternal interface, was down-regulated following RV infection only in HUVEC. Most noticeably, when analyzing the uniquely regulated transcripts for each cell type, GO term-based cluster analysis of the down-regulated genes of HUVEC revealed an enrichment of the GO terms "sensory organ development", "ear development" and "eye development".

CONCLUSION

Since impairment in vision and hearing are the most prominent clinical manifestations observed in CRS patients, the here detected down-regulated genes involved in the development of sensory organs sheds light on the molecular mechanisms that may contribute to the teratogenic effect of RV.

Does Rubella Cause Autism: A 2015 Reappraisal?

In the 1970s, Stella Chess found a high prevalence of autism in children with congenital rubella syndrome (CRS), 200 times that of the general population at the time. Many researchers quote this fact to add proof to the current theory that maternal infection with immune system activation in pregnancy leads to autism in the offspring. This rubella and autism association is presented with the notion that rubella has been eliminated in today’s world. CRS cases are no longer typically seen; yet, autistic children often share findings of CRS including deafness, congenital heart defects, and to a lesser extent visual changes. Autistic children commonly have hyperactivity and spasticity, as do CRS children. Both autistic and CRS individuals may develop type 1 diabetes as young adults. Neuropathology of CRS infants may reveal cerebral vasculitis with narrowed lumens and cerebral necrosis. Neuroradiological findings of children with CRS show calcifications, periventricular leukomalacia, and dilated perivascular spaces. Neuroradiology of autism has also demonstrated hyperintensities, leukomalacia, and prominent perivascular spaces. PET studies of autistic individuals exhibit decreased perfusion to areas of the brain similarly affected by rubella. In both autism and CRS, certain changes in the brain have implicated the immune system. Several children with autism lack antibodies to rubella, as do children with CRS. These numerous similarities increase the probability of an association between rubella virus and autism. Rubella and autism cross many ethnicities in many countries. Contrary to current belief, rubella has not been eradicated and globally affects up to 5% of pregnant women. Susceptibility continues as vaccines are not given worldwide and are not fully protective. Rubella might still cause autism, even in vaccinated populations.

Seroprevalence and Influence of Torch Infections in High Risk Pregnant Women: A Large Study from South India

BACKGROUND

The increased complications to the mother and fetus during or after pregnancy and birth are often caused by a wide array of pathogenic organisms mostly belonging to the TORCH group [toxoplasmosis, rubella, cytomegalovirus (CMV), and herpes simplex virus (HSV)]. These agents cause asymptomatic or mild infection in the mother while serious consequences in fetus. The present study was aimed to find significant etiological pathogens in the causation of high risk pregnancy (HRP) in South Indian population.

MATERIAL AND METHODS

A total of 1,158 HRP women (2010-2013) from Modern Government Maternity Hospital, Hyderabad were considered. Two milliliter of blood was obtained and the serum was analyzed for IgG and IgM antibodies against TORCH agents by ELISA.

RESULTS

Twenty-five percent of the study group had fetal congenital malformation in the present pregnancy (Group 1; N = 291) while 75 % showed bad obstetric history (BOH) (Group 2; N = 867). Maternal age of ≤25 years, primi gravida, and consanguinity showed predisposing role for Group 1 while maternal age ≥30 years and ≥ 3 gravida were contributing risk for Group 2. The seropositvity in HRP women for toxoplasma, rubella, CMV, and HSV was 28, 84, 92, and 61 %, respectively for IgG while it was 6, 3, 4, and 3 % for IgG + IgM. Total seropositvity of toxoplasma, rubella, CMV, and HSV in Group 1 was 29, 97, 97, and 62 % while it was 36, 84, 97, and 65 % in Group 2, respectively.

CONCLUSION

Maternal age of ≤25 years, primi gravida, and consanguinity contributed to fetal congenital malformation in the present pregnancy while maternal age of ≥30 years and ≥ 3 gravida towards BOH. Toxoplasma is protective while rubella and CMV are the infectious agents for HRP. Among the groups, toxoplasma and rubella conferred a predisposing risk towards Group 2 and Group 1, respectively. Sixty-one percent seropositvity of HSV in relation to bad obstetric outcome is the highest prevalence reported so far in India.

Rubella outbreak in a Rural Kenyan District, 2014: documenting the need for routine rubella immunization in Kenya

Background

Rubella infection has been identified as a leading cause of birth defects commonly known as Congenital Rubella Syndrome (CRS). Kenya does not currently have a rubella immunization program nor a CRS surveillance system. In 2014, a rubella outbreak was reported in a rural district in Kenya. We investigated the outbreak to determine its magnitude and describe the outbreak in time, place and person. We also analyzed the laboratory-confirmed rubella cases from 2010 to 2014 to understand the burden of the disease in the country.

Methods

The Rubella outbreak was detected using the case-based measles surveillance system. A suspected case was a person with generalized rash and fever while a confirmed case was a person who tested positive for rubella IgM. All laboratory-confirmed and epidemiologically linked cases were line listed. The measles case-based surveillance database was used to identify rubella cases from 2010 to 2014.

Results

A total of 125 rubella cases were line listed. Fifty four percent of cases were female. Case age ranged from 3 months to 32 years with a median of 4 years. Fifty-one percent were aged less than 5 years, while 82 % were aged less than 10 years. Six percent of the cases were women of reproductive age. All cases were treated as outpatients and there were no deaths. The number of confirmed rubella cases was 473 in 2010, 604 in 2011, 300 in 2012, 336 in 2013 and 646 in 2014.

Conclusions

Analysis of Kenya rubella data shows that rubella is endemic throughout the country, and many outbreaks may be underestimated or undocumented. Six percent of all the cases in this outbreak were women of reproductive age indicating that the threat of CRS is real. The country should consider initiating a CRS surveillance system to quantify the burden with the goal of introducing rubella vaccine in the future.

Nitric oxide-sensitive pulmonary hypertension in congenital rubella syndrome

Persistent pulmonary hypertension is a very rare presentation of congenital virus infection. We discuss the case of complete congenital rubella syndrome presenting at echocardiography with pulmonary hypertension that worsened after ductus ligation. Cardiac catheterization showed a normal pulmonary valve and vascular tree but a PAP = 40 mmHg. The infant promptly responded to inhaled nitric oxide while on mechanical ventilation and was later shifted to oral sildenafil. It is not clear whether our observation may be due to direct viral damage to the endothelium or to the rubella virus increasing the vascular tone via a metabolic derangement.

Viral infections during pregnancy

Viral infections during pregnancy have long been considered benign conditions with a few notable exceptions, such as herpes virus. The recent Ebola outbreak and other viral epidemics and pandemics show how pregnant women suffer worse outcomes (such as preterm labor and adverse fetal outcomes) than the general population and non-pregnant women. New knowledge about the ways the maternal-fetal interface and placenta interact with the maternal immune system may explain these findings. Once thought to be 'immunosuppressed', the pregnant woman actually undergoes an immunological transformation, where the immune system is necessary to promote and support the pregnancy and growing fetus. When this protection is breached, as in a viral infection, this security is weakened and infection with other microorganisms can then propagate and lead to outcomes, such as preterm labor. In this manuscript, we review the major viral infections relevant to pregnancy and offer potential mechanisms for the associated adverse pregnancy outcomes.

Determining rubella immunity in pregnant Alberta women 2009-2012

Rubella IgG levels for 157,763 pregnant women residing in Alberta between 2009 and 2012 were analyzed. As there have been no reported cases of indigenous rubella infection in Canada since 2005, there has been a lack of naturally acquired immunity, and the current prenatal population depends almost entirely on vaccine induced immunity for protection. Rubella antibody levels are significantly lower in younger maternal cohorts with 16.8% of those born prior to universal vaccination programs (1971-1980), and 33.8% of those born after (1981-1990) having IgG levels that are not considered protective (<15 IU/mL). Analysis across pregnancies showed only 35.0% of women responded with a 4-fold increase in antibody levels following post-natal vaccination. Additionally, 41.2% of women with antibody levels <15 IU/mL had previously received 2 doses of rubella containing vaccine. These discordant interpretations generate a great deal of confusion for laboratorians and physicians alike, and result in significant patient follow-up by Public Health teams. To assess the current antibody levels in the prenatal population, latent class modeling was employed to generate a two class fit model representing women with an antibody response to rubella, and women without an antibody response. The declining level of vaccine-induced antibodies in our population is disconcerting, and a combined approach from the laboratory and Public Health may be required to provide appropriate follow up for women who are truly susceptible to rubella infection.

Rubella virus: first calcium-requiring viral fusion protein

Rubella virus (RuV) infection of pregnant women can cause fetal death, miscarriage, or severe fetal malformations, and remains a significant health problem in much of the underdeveloped world. RuV is a small enveloped RNA virus that infects target cells by receptor-mediated endocytosis and low pH-dependent membrane fusion. The structure of the RuV E1 fusion protein was recently solved in its postfusion conformation. RuV E1 is a member of the class II fusion proteins and is structurally related to the alphavirus and flavivirus fusion proteins. Unlike the other known class II fusion proteins, however, RuV E1 contains two fusion loops, with a metal ion complexed between them by the polar residues N88 and D136. Here we demonstrated that RuV infection specifically requires Ca²⁺ during virus entry. Other tested cations did not substitute. Ca²⁺ was not required for virus binding to cell surface receptors, endocytic uptake, or formation of the low pH-dependent E1 homotrimer. However, Ca²⁺ was required for low pH-triggered E1 liposome insertion, virus fusion and infection. Alanine substitution of N88 or D136 was lethal. While the mutant viruses were efficiently assembled and endocytosed by host cells, E1-membrane insertion and fusion were specifically blocked. Together our data indicate that RuV E1 is the first example of a Ca²⁺-dependent viral fusion protein and has a unique membrane interaction mechanism.

Rubella virus (RuV) is a small enveloped RNA virus causing mild disease in children. However, infection of pregnant women can produce fetal death or congenital rubella syndrome, a constellation of severe birth defects including cataracts, hearing loss, heart disease and developmental delays. While vaccination has greatly reduced disease in the developed world, rubella remains prevalent in developing countries and other undervaccinated populations. RuV infects cells by endocytic uptake and a low pH-triggered membrane fusion reaction mediated by the viral E1 protein. The postfusion structure of E1 revealed a metal ion complexed at the membrane-interacting tip of the protein. Here we demonstrated that RuV infection and fusion are completely dependent on calcium, which could not be replaced functionally by any other metal that was tested. In the absence of calcium, RuV entry and low pH-conformational changes were unchanged, but E1's interaction with the target membrane was specifically blocked. Mutations of the calcium-binding residues in E1 caused a similar inhibition of E1 membrane interaction, fusion and infection. Thus, RuV E1 is the first known example of a calcium-dependent virus fusion protein.

Molecular evolutionary and epidemiological dynamics of genotypes 1G and 2B of rubella virus

Rubella Virus (RV), which causes measles-like rashes in children, puts millions of infants at risk of congenital defects across the globe. Employing phylogenetic approaches to the whole genome sequence data and E1 glycoprotein sequence data, the present study reports the substitution rates and dates of emergence of all thirteen previously described rubella genotypes, and gains important insights into the epidemiological dynamics of two geographically widely distributed genotypes 1G and 2B. The overall nucleotide substitution rate of this non-vector-borne RV is in the order of 10-3 substitutions/site/year, which is considerably higher than the substitution rates previously reported for the vector-borne alphaviruses within the same family. Currently circulating strains of RV share a common ancestor that existed within the last 150 years, with 95% Highest Posterior Density values ranging from 1868 to 1926 AD. Viral strains within the respective genotypes began diverging between the year 1930 s and 1980 s. Both genotype 1G and 2B have shown a decline in effective number of infections since 1990 s, a period during which mass immunization programs against RV were adapted across the globe. Although both genotypes showed some extent of spatial genetic structuring, the analyses also depicted an inter-continental viral dispersal. Such a viral dispersal pattern could be related to the migration of infected individuals across the regions coupled with a low coverage of MMR vaccination.

Prenatal diagnosis of congenital rubella infection in São Paulo

Objective: rubella during the early stages of pregnancy can lead to severe birth defects known as congenital rubella syndrome (CRS). Samples collected from pregnant women with symptoms and suspected of congenital rubella infection between 1996 and 2008 were analyzed. Methods: a total of 23 amniotic fluid samples, 16 fetal blood samples, 1 product of conception and 1 placenta were analyzed by serology and RT-PCR. Results: all patients presented positive serology for IgG / IgM antibodies to rubella virus. Among neonates, 16 were IgG-positive, 9 were IgM-positive and 4 were negative for both antibodies. Of the 25 samples analyzed in this study, 24 were positive by RT-PCR. Changes in ultrasound were found in 15 (60%) of 25 fetuses infected with rubella virus. Fetal death and miscarriage were reported in 10 (40%) of the 25 cases analyzed. The rubella virus was amplified by PCR in all fetuses with abnormal ultrasound compatible with rubella. Fetal death and abortion were reported in 10 of 25 cases analyzed. Conclusion: this study, based on primary maternal rubella infection definitely confirms the good sensitivity and specificity of RT-PCR using amniotic fluid and ultrasound. The results showed that molecular assays are important tools in the early diagnosis of rubella and congenital rubella syndrome.

Rubella and pregnancy: diagnosis, management and outcomes

Rubella is a mild viral disease that typically occurs in childhood. Rubella infection during pregnancy causes congenital rubella syndrome, including the classic triad of cataracts, cardiac abnormalities and sensorineural deafness. Highly effective vaccines have been developed since 1969, and vaccination campaigns have been established in many countries. Although there has been progress, the prevention and diagnosis of rubella remain problematic. This article reviews the implications and management of rubella during pregnancy.

NEGATIVE REGULATORY EFFECTS OF PHOSPHATIDYLINOSITOL3-KINASE PATHWAY ON PHAGOCYTOSIS AND MACROPINOCYTOSIS IN BOVINE MONOCYTES

Recent studies have shown that monocytes and macrophages not only present antigens to effector T cells and stimulate and shape T cell-mediated immune responses, but they also prime naïve T cells, thus initiating adaptive immune responses. Phosphatidylinositol 3-kinase functions at an early phase of toll-like receptor signaling pathways, modulates the magnitude of the primary immune responses, and is involved in the reorganization of the actin cytoskeleton during macropinocytic and phagocytic antigen uptakes, important early steps in triggering adaptive immune responses. We assessed by flow cytometry the endocytic capacities of bovine monocytes by using endocytic tracers and Salmonella transformed with a green fluorescence plasmid GFP to evaluate macropinocytosis, mannose receptor-mediated endocytosis, and phagocytosis in bovine professional antigen presenting cells, respectively. Our data reveal that wortmannin, an inhibitor of phosphatidylinositol 3-kinase signaling pathway, significantly increased macropinocytosis and phagocytosis but did not affect the mannose receptor-mediated antigen uptake in bovine monocytes. Protein expression data support these findings by showing decreased levels of phosphoinositide 3-kinase in the presence of wortmannin during macropinocytosis. We expanded further the key role of phosphatidylinositol 3-kinase as an endogenous suppressor of primary immune responses, suggesting a novel mechanism of phosphatidylinositol 3-kinase antigen uptake modulation that may provide a unique therapeutic target for controlling excessive inflammation.

Identification of germinal centres in the lymph node of a patient with hyperimmunoglobulin M syndrome associated with congenital rubella

BACKGROUND

The hyper immunoglobulin M syndrome (HIM) associated with congenital rubella infection (rHIM) is an extremely rare disorder, where patients have elevated serum IgM in association with reduced IgG and IgA. We have previously shown that in contrast to X-linked HIM (XHIM), a patient with well-characterised rHIM is able to express functional CD40 ligand, undergo immunoglobulin isotype switching and to generate memory B cells. Here we describe the ultrastructural features of an excised lymph node from this patient.

METHODS

An inguinal lymph node was surgically removed and examined histologically as well as by immunohistochemistry. It was then stained with multiple fluorescent dyes to visualize the cellular interactions within the node. Flow cytometry was undertaken on a cellular suspension from the node.

FINDINGS

Our patient has normal lymph node architecture by light microscopy. Immunohistochemistry studies showed the presence of scattered germinal centres. Polychromatic immunofluorescence staining showed disruption of the architecture with mostly abnormal germinal centres. A small number of relatively intact germinal centres were identified. Both IgM and IgG bearing cells were identified in germinal centres.

INTERPRETATION

In contrast to XHIM where germinal centres are absent, the presence of small numbers of relatively normal germinal centres explain our previous identification of isotype switched memory B cells in rHIM.

Viral causes of hearing loss: a review for hearing health professionals

A number of viral infections can cause hearing loss. Hearing loss induced by these viruses can be congenital or acquired, unilateral or bilateral. Certain viral infections can directly damage inner ear structures, others can induce inflammatory responses which then cause this damage, and still others can increase susceptibility or bacterial or fungal infection, leading to hearing loss. Typically, virus-induced hearing loss is sensorineural, although conductive and mixed hearing losses can be seen following infection with certain viruses. Occasionally, recovery of hearing after these infections can occur spontaneously. Most importantly, some of these viral infections can be prevented or treated. For many of these viruses, guidelines for their treatment or prevention have recently been revised. In this review, we outline many of the viruses that cause hearing loss, their epidemiology, course, prevention, and treatment.

Genomic analysis of the Chinese genotype 1F rubella virus that disappeared after 2002 in China

Genotype 1F was likely localized geographically to China as it has not been reported elsewhere. In this study, whole genome sequences of two rubella 1F virus isolates were completed. Both viruses contained 9,761 nt with a single nucleotide deletion in the intergenic region, compared to the NCBI rubella reference sequence (NC 001545). No evidence of recombination was found between 1F and other rubella viruses. The genetic distance between 1F viruses and 10 other rubella virus genotypes (1a, 1B, 1C, 1D, 1E, 1G, 1J 2A, 2B, and 2C) ranged from 3.9% to 8.6% by pairwise comparison. A region known to be hypervariable in other rubella genotypes was also the most variable region in the 1F genomes. Comparisons to all available rubella virus sequences from GenBank identified 22 nucleotide variations exclusively in 1F viruses. Among these unique variations, C9306U is located within the recommended molecular window for rubella virus genotyping assignment, could be useful to confirm 1F viruses. Using the Bayesian Markov Chain Monte Carlo (MCMC) method, the time of the most recent common ancestor for the genotype 1F was estimated between 1976 and 1995. Recent rubella molecular surveillance suggests that this indigenous strain may have circulated for less than three decades, as it has not been detected since 2002.

Identification of congenital rubella syndrome in Sudan

Background

Epidemiological data about congenital rubella syndrome (CRS) are scarce and rubella vaccine is not yet included in the childhood immunization schedule in Sudan. This study aimed to identify and describe CRS cases among Sudanese infants with congenital eye or heart defects.

Methods

Between February and September 2010, paired oral fluid and dried blood spot samples were collected from 98 infants aged up to 12 months. These infants were enrolled during their visits to five hospitals in Khartoum, Sudan. Clinical samples were screened for rubella IgM and for ≥ 6 months old infants also for IgG antibodies by ELISA. The oral fluid of IgM and/or IgG positive patients was tested for rubella RNA by reverse transcriptase PCR.

Results

Our findings revealed that two children (2.0%) were IgM positive and another five children (5.1%) were positive for IgG antibodies. None of the five infants of which enough oral fluid was available for RNA investigation was PCR positive.

Conclusions

This study documented the presence of CRS in Sudan and highlighted the importance of rubella vaccine introduction for preventing future CRS cases in the country.

Rubella virus perturbs autophagy

Autophagy is a cellular catabolic process implicated in numerous physiological processes and pathological conditions, including infections. Viruses have evolved different strategies to modulate the autophagic process. Since the effects of rubella virus (RV) on autophagy have not yet been reported, we evaluated the autophagic activity in the Statens Seruminstitut Rabbit Cornea cell line infected with the To336 strain of RV. Our results showed that RV lowered the levels of microtubule-associated protein 1 light chain 3 B-II (LC3B-II) and the autophagy-related gene 12-autophagy-related gene 5 conjugate, inhibited the autophagic flux, suppressed the intracellular redistribution of LC3B, decreased both the average number and the size of autophagosomes per cell and impeded the formation of acidic vesicular organelles. Induction of autophagy by using rapamycin decreased both the viral yields and the apoptotic rates of infected cultures. Besides its cytoprotective effects, autophagy furnishes an important antiviral mechanism, inhibition of which may reorchestrate intracellular environment so as to better serve the unique requirements of RV replication. Together, our observations suggest that RV utilizes a totally different strategy to cope with autophagy than that evolved by other positive-stranded RNA viruses, and there is considerable heterogeneity among the members of the Togaviridae family in terms of their effects on the cellular autophagic cascade.

[Rubella: a current issue?]

Sporadic cases of rubella infection are reported each year in France due to insufficient vaccination coverage. Rubella virus is a very unstable enveloped RNA virus. For this reason, transportation and storage of samples collected for its detection require particular conditions. The genetic stability of rubella virus has allowed the development of very effective vaccines. During the recent rubella outbreaks in Algeria and Tunisia, an unusual high rate of encephalitis was reported. The role of the laboratory is crucial in the management of rubella infection during pregnancy. Rubella serological results must be interpreted with caution. Congenital rubella is a severe disease that should already be eliminated thanks to a very effective vaccine that has been developed. All women of childbearing age should be vaccinated. Rubella vaccination of an unknowingly pregnant woman is not an indication for abortion.

Influence of infection during pregnancy on fetal development

Infection by bacteria, viruses, and parasites may lead to fetal death, organ injury, or limited sequelae depending on the pathogen. Here, we consider the role of infection during pregnancy in fetal development including placental development and function, which can lead to fetal growth restriction. The classical group of teratogenic pathogens is referred to as 'TORCH' (Toxoplasma gondii, others like Treponema pallidum, rubella virus, cytomegalovirus, and herpes simplex virus) but should include a much broader group of pathogens including Parvovirus B19, Varicella zoster virus, and Plasmodium falciparum to name a few. In this review, we describe the influence of different infections in utero on fetal development and the short- and long-term outcomes for the neonate. In some cases, the mechanisms used by these pathogens to disrupt fetal development are well known. Bacterial infection of the developing fetal lungs and brain begins with an inflammatory cascade resulting in cytokine injury and oxidative stress. For some pathogens like P. falciparum, the mechanisms involve oxidative stress and apoptosis to disrupt placental and fetal growth. An in utero infection may also affect the long-term health of the infant; in many cases, a viral infection in utero increases the risk of developing type 1 diabetes in childhood. Understanding the varied mechanisms employed by these pathogens may enable therapies to attenuate changes in fetal development, decrease preterm birth, and improve survival.

How to use... neonatal TORCH testing

Toxoplasma gondii, rubella, cytomegalovirus and herpes simplex virus have in common that they can cause congenital (TORCH) infection, leading to fetal and neonatal morbidity and mortality. During the last decades, TORCH screening, which is generally considered to be single serum testing, has been increasingly used inappropriately and questions have been raised concerning the indications and cost-effectiveness of TORCH testing. The problems of TORCH screening lie in requesting the screening for the wrong indications, wrong interpretation of the single serum results and in case there is a good indication for diagnosis of congenital infection, sending in the wrong materials. This review provides an overview of the pathogenesis, epidemiology and clinical consequences of congenital TORCH infections and discusses the indications for, and interpretation of, TORCH screens.

Rubella epidemic caused by genotype 1E rubella viruses in Beijing, China, in 2007-2011

Background

A series of different rubella vaccination strategies were implemented to control rubella and prevent congenital rubella virus infection in Beijing, China. The rubella vaccine was available in 1995 in Beijing, and was introduced into the Beijing immunization program (vaccine recipients at their own expense vaccination) in 2000, and was introduced into the National Expanded Program on Immunization (vaccine recipients free vaccination) in 2006. Rubella virological surveillance started in Beijing in 2007.

Results

The reported rubella incidence rate has decreased dramatically due to the introduction of the vaccine in Beijing since 1995. However, rubella epidemics occurred regardless in 2001 and 2007. The incidence rate among the floating population has gradually increased since 2002, reaching 2 or more times that in the permanent resident population. The peak age of rubella cases gradually changed from <15 years of age to adults after 2005. Phylogenetic analysis was performed and a phylogenetic tree was constructed based on the World Health Organization standard sequence window for rubella virus isolates. All Beijing rubella virus isolates belong to genotype 1E/cluster1 and were clustered interspersed with viruses from other provinces in China. The effective number of infections indicated by a Bayesian skyline plot remained constant from 2007 to 2011.

Conclusions

The proportion of rubella cases among the floating population has increased significantly in Beijing since 2002, and the disease burden gradually shifted to the older age group (15- to 39-year olds), which has become a major group with rubella infection since 2006. Genotype 1E rubella virus continuously caused a rubella epidemic in Beijing in 2007–2011 and was the predominant virus, and all Beijing genotype 1E viruses belong to cluster 1, which is also widely circulated throughout the country.

[The structure of replication initiation region of Pseudomonas IncP-7 streptomycin resistance plasmid Rms148]

Pseudomonads' IncP-7 plasmids make significant contribution to the environmental biodegradative potential and sometimes harbour antibiotic resistance genes. More than 30 years plasmid Rms148 is used as archetypal P-7 plasmid in microbiological incompatibility tests. However, the structure of its basic replicon was not described up to now, as well as phylogenetic relationships between all known plasmids within the IncP-7 group were not studied. In the frames of this work we have constructed two primer pairs to amplify main components of P-7 replication initiation region, and subsequent screening of repA intragenic polymorphism was made using laboratory collection of IncP-7 plasmids. Minimal replicon of Rms148 was constructed and its nucleotide sequence was determined to be identical to repA-oriVof known P-7 plasmids on 81-83% and forming separate branch on appropriate phylogenetic tree. Additionally, repA seems to be more conservative between group members compared with putative oriV region. Deduced amino acid sequence and predicted secondary and tertiary structures of Rms148 RepA protein allow us to make assumption about similar to unclassified cryptic plasmid pPS10 model of replication initiation for IncP-7 group members.