Mother-to-infant transmission of multiple blood-borne viral infections from multi-infected mothers

Constant companion: clinical and developmental aspects of torque teno virus infections

Torque teno virus (TTV) is a commensal human virus observed as a circular single-negative-strand DNA molecule in various tissues and biological samples, notably in blood serum and lymphocytes. TTV has no apparent clinical significance, although it might be very useful as a prospective tool for gene delivery or as an epidemiological marker. Human populations are ubiquitously infected with TTV; the prevalence may reach 100%. The majority of babies become spontaneously infected with TTV, so that by the end of the first year of life, the prevalence reaches 'adult' values. TTV positivity in healthy early infancy and the presence of TTV in umbilical cord blood samples have been reported. The mechanism of infection and the dynamics of TTV prevalence in infants with age remain understudied. Meanwhile, the potential diagnostic and prognostic value of TTV as a marker deserves special attention and study, along with the possibility, causes and consequences of placental transmission of TTV under normal or pathological conditions.

Vertical Hepatitis C Virus Transmission is not Related to Mother-Child Class-1 HLA Concordance

Mother-child human leukocyte antigen (HLA) diversity is protective for vertical transmission of some viruses. The aim of this study is to evaluate the role of mother-child HLA diversity on hepatitis C virus (HCV) vertical transmission. Forty consecutive HCV infected and 46 consecutive control uninfected children born to HCV-RNA positive mothers were evaluated for HLA class-1 type concordance with their mothers. No significant difference in the degree of HLA concordance was found between HCV infected and uninfected children both when A, B, C ( p=0.30) and when only A and B alleles were evaluated ( p=0.59). Mother-infant HLA concordance does not affect HCV vertical transmission.

Hepatitis C in Children Co-infected With Human Immunodeficiency Virus

OBJECTIVES

The objective of this systematic review was to summarize evidence regarding hepatitis C in hepatitis C virus/human immunodeficiency virus (HCV/HIV)-co-infected children focusing on mother-to-child transmission, clinical and laboratory features, outcome, and therapies.

METHODS

A literature search was performed using multiple keywords and standardized terminology in MEDLINE, EMBASE, and Cochrane databases dating back to their inception up to April 1, 2015, using the following terms hepatitis C virus, HIV, and child.

RESULTS

Fifty-five of 367 publications were selected for inclusion. In co-infected children, HIV impacted all the different aspects of HCV infection. Maternal HIV infection increased the risk of vertical transmission of hepatitis C. Children with HCV/HIV co-infection presented a lower rate of spontaneous clearance of HCV, were more commonly HCV viraemic, and had higher values of alanine aminotransferase when compared with HCV-monoinfected children. No relevant difference was reported between monoinfection and co-infection with regard to clinical findings. Although the data on the outcome of hepatitis C in the context of co-infection were limited, they were highly suggestive of a more severe outcome in terms of fibrosis in co-infected children. No pediatric data were available on the role of antiretroviral therapy as a cofactor of liver injury in HCV/HIV co-infection. The efficacy of pegylated interferon-α and ribavirin in children with HCV/HIV co-infection was lower than in monoinfected children.

CONCLUSIONS

The effect of HIV co-infection on HCV-related disease was clear with most studies indicating that HIV accelerates HCV progression and reduces the efficacy of the available anti-HCV therapies.

Hepatitis C virus infection of human cytotrophoblasts cultured in vitro

Hepatitis C virus (HCV) infection in the uterus is a significant path of vertical HCV transmission. Some studies consider vertical HCV transmission in the uterus as the result of maternal blood leakage into infant blood, whereas others theorize that HCV is transmitted by the mother to the infant through cells constituting the placenta barrier. Although trophoblasts play an important role in the placenta barrier, no definitive evidence has been presented to prove that cytotrophoblasts can be infected with HCV. The current study investigated whether or not these can be infected with HCV by conducting an experiment, in which cultured human cytotrophoblasts were infected with HCV in vitro. The results were analyzed using reverse transcription polymerase chain reaction (RT-PCR), ultrastructural characteristic changes under an electron microscope, and immunoelectron microscopy. HCV RNA in the supernatant of the cultured medium of the infected group was intermittently detected during the 16-day incubation period using RT-PCR. Under an electron microscope, the ultrastructures of infected human cytotrophoblasts were markedly different from normal cells, demonstrating lysosomal hyperplasia, rough endoplasmic reticulum, decreased lipid droplets, presence of vacuoles, and the appearance of HCV-like particles. Using immunoelectron microscopy, HCV-like particles conjoined with golden granules were also observed. Based on the data, the current study concludes that HCV infects a human cytotrophoblast cultured in vitro; moreover, its ultrastructure changes dramatically upon infection.

Clinical care versus ethical obligations: HIV-1 and -2 co-infection with hepatitis B in a pregnant Jehovah's Witness

Co-infection with HIV-1 and -2 is rare, even in west Africa. We present the case of a 38-year-old pregnant Jehovah's Witness presenting late in pregnancy with triple infection with HIV-1, HIV-2 and hepatitis B virus. There was a successful outcome in averting vertical transmission despite objections to management based on religious and cultural beliefs.

TT viruses: oncogenic or tumor-suppressive properties?

Torque teno (TT) viruses have been more frequently reported in malignant biopsies when compared to normal control tissue. The possible contribution of TT virus infection to human carcinogenesis or the potential oncolytic functions of these virus infections are being discussed based on available experimental evidence. The data could suggest an involvement of TT virus infections as an indirect carcinogen by modulating T cell immune responses. Significant oncolytic functions, potentially mediated by the inhibition of nuclear factor (NF)-kappaB transcription factor or by apoptin-like gene activities, are emerging to be less likely.

Unraveling the puzzle of human anellovirus infections by comparison with avian infections with the chicken anemia virus

Current clinical studies on human annelloviruses infections are directed towards finding an associated disease. In this review we have emphasized the many similarities between human anellovirus and avian circoviruses and the cell and tissue types infected by these pathogens. We have done this in order to explore whether knowledge acquired from natural and experimental avian infections could reflect and be extrapolated to the less well-characterized human annellovirus infections. The knowledge gained from the avian system may provide suggestions for decoding the enigmatic human anellovirus infections, and finding the specific disease or diseases caused by these human anellovirus infections. Each additional parallelism between chicken anemia virus (CAV) and Torque teno virus (TTV) further strengthens this premise. As we have seen information from human infections can also be used to better understand avian infections as well. Increased attention must be focused on the "hidden" or unrecognized, seemingly asymptomatic effects of circovirus and anellovirus infections. Understanding the facilitating effect of these infections on disease progression caused by other pathogens may help to explain differences in outcome of complicated poultry and human diseases. The final course of a pathogenic infection is determined by variations in the state of health of the host before, during and after contact with a pathogen, in addition to the phenotype of the pathogen and host. The health burden of circoviridae and anellovirus infections may be underestimated, due to lack of awareness of the need to search past the predominant clinical effect of identified pathogens and look for modulation of cellular-based immunity caused by co-infecting circoviruses, and by analogy, human anneloviruses.