Analysis of Morphological Changes in the CNS and Internal Organs of Macaca mulatta Monkeys after Intracerebral Injection of a Low-Attenuated Rubella Virus Strain.

We studied the localization and severity of morphological changes in CNS and internal organs of animals intacerebrally infected with a low-attenuated rubella virus strain "Orlov-14". The data obtained can be used as morphological criteria reflecting low level of attenuation of rubella virus strains to improve the control of the safety of attenuated strains of live rubella vaccines.

Assembly, maturation and three-dimensional helical structure of the teratogenic rubella virus.

Viral infections during pregnancy are a significant cause of infant morbidity and mortality. Of these, rubella virus infection is a well-substantiated example that leads to miscarriages or severe fetal defects. However, structural information about the rubella virus has been lacking due to the pleomorphic nature of the virions. Here we report a helical structure of rubella virions using cryo-electron tomography. Sub-tomogram averaging of the surface spikes established the relative positions of the viral glycoproteins, which differed from the earlier icosahedral models of the virus. Tomographic analyses of in vitro assembled nucleocapsids and virions provide a template for viral assembly. Comparisons of immature and mature virions show large rearrangements in the glycoproteins that may be essential for forming the infectious virions. These results present the first known example of a helical membrane-enveloped virus, while also providing a structural basis for its assembly and maturation pathway.

The pathogenesis of microcephaly resulting from congenital infections: why is my baby's head so small?

The emergence of Zika-virus-associated congenital microcephaly has engendered renewed interest in the pathogenesis of microcephaly induced by infectious agents. Three of the original "TORCH" agents are associated with an appreciable incidence of congenital microcephaly: cytomegalovirus, rubella virus, and Toxoplasma gondii. The pathology of congenital microcephaly is characterized by neurotropic infectious agents that involve the fetal nervous system, leading to brain destruction with calcifications, microcephaly, sensorineural hearing loss, and ophthalmologic abnormalities. The inflammatory reaction induced by these four agents has an important role in pathogenesis. The potential role of "strain differences" in pathogenesis of microcephaly by these four pathogens is examined. Specific epidemiologic factors, such as first and early second trimester maternal infection, and the manifestations of congenital infection in the infant, shed some light on the pathogenesis. Immune aspects of normal pregnancy and their role in congenital infections is examined. In this review, we integrate all these findings to create a unified hypothesis of the pathogenesis of congenital microcephaly induced by these infectious agents.

[Epidemiologic control for rubella in pregnant women].

AIM: Evaluate effectiveness of measures specified by epidemiologic control for rubella in pregnant women. MATERIALS AND METHODS: 585 pregnant women with suspected measles were laboratory examined in 10 Regional Centers of Control for Measles and Rubella by EIA. RESULTS: 24 rubella infected pregnant women aged 16-36 years were detected among the examined pregnant women, most of those (91.7%) were either not immunized against rubella or had unknown immunization anamnesis: 16 women terminated pregnancy, in 8 women pregnancy ended with delivery at term. Of the 8 newborns only a single child had innate rubella infection (the child was clinically healthy). CONCLUSION: Epidemiologic investigation of each rubella case in pregnant women with obligatory laboratory examination of women and source of infection revealed a significant number of women at childbearing age susceptible to rubella virus that retains the possibility of birth of children with innate rubella syndrome.

Infections at the maternal-fetal interface: an overview of pathogenesis and defence.

Infections are a major threat to human reproductive health, and infections in pregnancy can cause prematurity or stillbirth, or can be vertically transmitted to the fetus leading to congenital infection and severe disease. The acronym 'TORCH' (Toxoplasma gondii, other, rubella virus, cytomegalovirus, herpes simplex virus) refers to pathogens directly associated with the development of congenital disease and includes diverse bacteria, viruses and parasites. The placenta restricts vertical transmission during pregnancy and has evolved robust mechanisms of microbial defence. However, microorganisms that cause congenital disease have likely evolved diverse mechanisms to bypass these defences. In this Review, we discuss how TORCH pathogens access the intra-amniotic space and overcome the placental defences that protect against microbial vertical transmission.

Institutional outbreak of rubella in a healthcare center in Chandigarh, North India.

Rubella is traditionally considered a childhood disease but it has the potential to cause outbreaks in closed communities when a susceptible population accumulates. The present study reports an outbreak of rubella among healthcare workers in the pediatric center of a tertiary care North Indian hospital. The cases of rubella were identified by clinical features and confirmed by the detection of anti-rubella IgM antibodies in blood by enzyme linked immunosorbent assay. A total of 23 cases of rubella occurred over a period of one and a half month, out of which 9 (39%) were males. All the patients were in the age group of 21-35 years. None of the patients gave a history of rubella vaccination. This outbreak of rubella occurred due to the accumulation of a susceptible population in a closed hospital environment. There is need for the introduction of rubella vaccination in healthcare workers to prevent outbreaks at work place.

Encephalitis in a child during atypical course of rubella.

Rubella is usually encountered as a mild viral illness in children and complications are not common. We reported rubella encephalitis in the atypical course of rubella without rash in a 9-year-old boy. He was admitted with a headache, fever, loss of consciousness and bilateral retroauricular lymphadenopathy. The cerebrospinal fluid (CSF) examination showed lymphocytic pleocytosis, increased protein levels and a normal glucose value. Immunoglobulin (Ig) M antibodies against rubella virus were positive in CSF and serum. IgG antibody also became positive in his serum 3 weeks after his admittance. We emphasized that rubella may appear without any rash and cause encephalitis. In unvaccinated children, rubella should be considered in the differential diagnosis of encephalitis.

Congenital B-cell Acute Lymphoblastic Leukemia with Congenital Rubella Infection.

BACKGROUND: Congenital B-cell Acute lymphoblastic leukemia (ALL) is a rare malignancy. CHARACTERISTICS: A newborn infant presented with purpuric spots and ecchymotic patches, blueberry muffin rash, depressed neonatal reflexes, respiratory distress and hepatosplenomegaly. Peripheral smear revealed atypical blast cells. Serum ELISA was positive for Rubella IgM and IgG antibodies. Flow cytometry suggested congenital B-cell ALL. OUTCOME: The baby died after 3 days due to suspected intracranial hemorrhage. MESSAGE: Congenital leukemia may be rarely associated with congenital rubella infection.

Immunopathology of Virus-Induced Anterior Uveitis.

Herpes simplex virus, varicella zoster virus, human cytomegalovirus, and rubella virus are the most common causes of virus-induced anterior uveitis. They can present in a variety of entities not only with typical but also overlapping clinical characteristics. These viral infections are commonly associated with ocular infiltration of T cells and B/plasma cells, and expression of cytokines and chemokines typical of a proinflammatory immune response. The infections differ in that the herpes viruses cause an acute lytic infection and inflammation, whereas rubella virus is a chronic low-grade infection with slowly progressing immunopathological responses. The outcome of an intraocular viral infection may largely be guided by the characteristics of the virus, which subsequently dictates the severity and type of the immune response, and the host immune status.

Altered growth, differentiation, and responsiveness to epidermal growth factor of human embryonic mesenchymal cells of palate by persistent rubella virus infection.

We previously demonstrated that human embryonic mesenchymal cells derived from the palate (HEMP cells) retain alkaline phosphatase (ALP) content and capacity for collagen synthesis after long-term culture, and their growth is markedly stimulated by epidermal growth factor (EGF). There was a dramatic decrease in ALP content and capacity to synthesize collagen in HEMP cells (HEMP-RV cells) persistently infected with rubella virus (RV). EGF increased ALP activity and decreased collagen synthesis in HEMP cells, whereas EGF showed no effect on these activities in HEMP-RV cells. Growth of HEMP-RV cells was slightly reduced compared with that of HEMP cells. EGF stimulated growth of HEMP cells and to a lesser extent of HEMP-RV cells. Binding of 125I-EGF to cell-surface receptors in HEMP-RV cells was, to our surprise, twice as much as that in HEMP cells. However, internalization of bound 125I-EGF in HEMP-RV cells was profoundly diminished. Thus, persistent RV infection causes not only changes in HEMP cell growth and differentiation but a decrease in or loss of HEMP cell responsiveness to EGF. The effects of persistent RV infection on palatal cell differentiation as well as growth may be responsible for the pathogenesis of congenital rubella. Furthermore, since HEMP cells appear to be closely related to osteoblasts, these results suggest a mechanism for RV-induced osseous abnormalities manifested in congenital rubella patients.

Rubella.

Rubella is associated with an 80% risk of congenital abnormalities if acquired in the first 12 weeks of pregnancy. Reinfection in early pregnancy presents a much smaller risk. Prenatal diagnosis may be useful to assess the risk to the fetus. Congenital rubella is a progressive disease and some abnormalities will not be present at birth. Rubella and congenital rubella are usually diagnosed by detection of rubella-specific IgM; it may be difficult to confirm a diagnosis of congenital rubella in children over 3 months of age. Rubella vaccines are usually combined with measles and mumps vaccines. Their use has enabled some industrialised countries to eliminate rubella and congenital rubella. Countries should ensure that susceptible women of child-bearing age and health care workers are offered a rubella-containing vaccine. Rubella vaccine is contraindicated during pregnancy, but if a pregnant woman is inadvertently vaccinated it is not an indication for termination or prenatal diagnosis.

Rubella in pregnancy: intrauterine transmission and perinatal outcome during a Brazilian epidemic.

Sixty pregnant women with clinical signs of rubella and specific rubella antibodies were studied between January 1999 and December 2002 in order to determine the intrauterine rubella transmission rate and the presence of the virus in amniotic fluid and fetal tissues by nested PCR. Thirty-three patients presented rubella before 12 weeks of gestation and 27 after 12 weeks. Gestational age at the time of acute rubella was determined on the basis of the date of last menstruation and the first trimester ultrasound scan. Thirteen patients with clinical features of rubella before 12 weeks of gestation were submitted to amniocentesis. Three products of conception were analyzed. The presence of the rubella virus was determined by nested PCR. IgM and IgG antibodies were analyzed in neonatal samples at birth and at 3 months of age using a capture immunoassay. Newborn follow-up was based on the presence of congenital rubella syndrome-compatible defects, anti-rubella antibodies, echocardiographic alterations, brainstem evoked response audiometry, and ophthalmological pathology. Five miscarriages and four fetal deaths were observed in the group of patients presenting clinical features before 12 weeks of gestation. IgM antibodies were detected in seven neonates at birth and at 3 months of age. Deafness was observed in three cases and pigmentary retinopathy in one case. Fourteen of the 16 samples (13 amniotic fluid and 3 fetal tissue samples) submitted to virological analysis tested positive. Four fetal deaths, five miscarriages (one with negative virology) and seven newborns with anti-rubella IgM at birth and/or at 3 months age were observed in the group with rubella before 12 weeks of gestation. There were three cases in which virological analysis of the amniotic fluid samples was positive (infected) while the newborn showed no signs of congenital rubella syndrome and anti-rubella IgM were absent. When maternal rubella occurred after 12 weeks of gestation, no fetal or neonatal rubella signs were observed. Eradication of congenital rubella syndrome is possible since vaccination campaigns continue and all services related to the health care of children, adolescents and women have become aware of the significance of the problem and are collaborating. All pregnant women in Brazil should be screened for the rubella antibody and the susceptible group should be vaccinated after giving birth.

Rubella virus-induced diabetes in the hamster.

The congenital rubella syndrome provides the best documentation in humans that a viral infection is associated with the subsequent development of insulin-dependent diabetes mellitus. We have developed an animal model in neonatal golden Syrian hamsters infected with rubella virus passaged in beta-cells that closely parallels the diabetes observed with congenital rubella. The hamsters develop hyperglycemia and hypoinsulinemia, which are sustained throughout the 15-wk study period. A mononuclear infiltration of the islets, isolation of rubella virus from whole pancreas, the presence of viral antigen in beta-cells by immunofluorescent localization, and cytoplasmic islet cell antibodies (40%) are demonstrated. These data suggest that an autoimmune process and diabetes develop after rubella virus infection in neonatal hamsters. This model may uncover the precise mechanism by which rubella virus induces similar disease in humans.

Pathogenesis of Congenital Rubella Virus Infection in Human Fetuses: Viral Infection in the Ciliary Body Could Play an Important Role in Cataractogenesis.

BACKGROUND: Development of congenital rubella syndrome associated with rubella virus infection during pregnancy is clinically important, but the pathogenicity of the virus remains unclear. METHODS: Pathological examination was conducted on 3 aborted fetuses with congenital rubella infection. FINDINGS: At autopsy, all 3 aborted fetuses showed congenital cataract confirmed by gross observation. Rubella virus infection occurred via systemic organs including circulating hematopoietic stem cells confirmed by immunohistochemical and molecular investigations, and major histopathogical changes were found in the liver. It is noteworthy that the virus infected the ciliary body of the eye, suggesting a possible cause of cataracts. INTERPRETATION: Our study based on the pathological examination demonstrated that the rubella virus infection occurred via systemic organs of human fetuses. This fact was confirmed by immunohistochemistry and direct detection of viral RNA in multiple organs. To the best of our knowledge, this study is the first report demonstrating that the rubella virus infection occurred via systemic organs of the human body. Importantly, virus infection of the ciliary body could play an important role in cataractogenesis.

Epidemiological characteristics of rubella and congenital rubella syndrome in the 2012-2013 epidemics in Tokyo, Japan.

A large rubella outbreak has been observed since June 2012 in Tokyo, Japan, and a rapid increase in the number of congenital rubella syndrome (CRS) cases have also been reported in Japan since October 2012. All the clinically diagnosed and laboratory-confirmed rubella cases reported in Tokyo from January 2012 to December 2013 and all the laboratory-confirmed CRS cases from January 2012 to March 2014 were analyzed. In total, 4,116 rubella cases were reported in Tokyo. Of these, 77.2% (n=3,176) were male; the highest number of cases occurred in males aged 35-39 years and in females aged 20-24 years. Complications included arthralgia/arthritis (19.4%), thrombocytopenic purpura (0.5%), hepatic dysfunction (0.3%), and encephalitis (0.1%). The circulating rubella virus in Tokyo was genotype 2B. The most possible site of transmission was the workplace. Because of the rubella epidemic, 16 CRS cases were reported in Tokyo from March 2013 to February 2014. Domestic infection with rubella was proven for all mothers of 16 cases. This situation suggests that Japan is still working to achieve rubella elimination.

Reinfection-induced increase of rubella persistently infected cells in a macrophage-like cell line.

The establishment and relevant characteristics of a long-term rubella persistent infected immortalised murine macrophage culture with a high proportion of persistent infected cells over uninfected is described. The high proportion of persistent infected macrophages was obtained through reinfection with the original virus. Prior to reinfection, 35-50% of the cells expressed viral antigen, 0.05-1.5% produced infective virus and extra-cellular virus was continuously produced with infective titers cyclically fluctuating between 10(2) and 10(7) TCID50/ml. After reinfection, the macrophages which expressed viral antigen and produced infective virus had increased to 75-90% and 30-45% respectively and extracellular virus was continuously produced with stable titer between 10(2)-10(3) TCID50/ml. Furthermore, in the reinfected culture no significant variation was observed in the percentage of cells expressing antigen, producing virus and in the titer of extracellular virus for longer than a year of passages.

Placental pathology in congenital rubella.

Two groups of placentae from 18 cases of maternal rubella were examined morphologically and virologically. Placentae in Group I (four cases) had a mean gestational age of 21 +/- 1.9 weeks, whilst those in Group 2 (14 cases) had a mean gestational age of 38 +/- 2.8 weeks. A tendency to hypoplasia was observed. The microscopic lesions were similar to those found in other viral infections but in each group some specific features were noted. Only placentae of Group I showed nodules of villi agglutinated by fibrin. This lesion suggested recent maternal infection. Attention is drawn to the presence of abnormal areas of lobular rarefaction due to dysmaturity of villous stem and terminal villi. This aspect was more diffuse and accentuated in Group 2 placentae. Villitis of reactive, necrotic, proliferative and reparative types was seen only in placentae of Group 2. Devastating villitis was not observed. Inclusions in placental cells suggested rubella infection. The lesions were non-specific and hence stress the need for virological examination of the placenta, immunofluorescence studies and electron microscopy to confirm the diagnosis.