HIV-I infection in perinatally exposed siblings and twins. The Italian Register for HIV Infection in Children

Challenging diagnosis of congenital malaria in non-endemic areas

Background

Congenital malaria is usually defined as the detection of asexual forms of Plasmodium spp. in a blood sample of a neonate during perinatal age if there is no possibility of postpartum infection by a mosquito bite. The incidence of congenital malaria is highly variable and seems related to several factors, such as different diagnostic methods for Plasmodium spp. detection, and area in which the epidemiologic analyses are performed. In non-endemic countries, cases of congenital malaria are rare. Hereby, a case of a congenital malaria in an HIV exposed child is reported.

Case presentation

A 2-month-old male child was admitted to Bambino Gesù Children’s Hospital due to anaemia and exposure to HIV. He was born prematurely in Italy by cesarean section at 34 weeks’ gestation after a bicorial, biamniotic pregnancy by a migrant woman from Nigeria. He was the first of non-identical twins. Combined with anaemia, spleen and liver enlargement was noted, malaria was hypothesized. Malaria laboratory panel was performed on the newborn, mother and other twin blood samples, as follows: (i) malaria rapid diagnostic test (RDT); (ii) Giemsa-stained thick and thin blood smears for Plasmodium spp. identification and parasitaemia titration; (iii) molecular screening and typing of Plasmodium spp. by multiplex qualitative PCR assay based on 18S rRNA gene. Genotyping of Plasmodium falciparum isolates from mother and child was performed by neutral microsatellite and highly polymorphic marker amplification.

Conclusions

The maternal RDT sample was negative, while the infant RDT was positive; in both cases microscopy of blood smears and PCR showed infection with P. falciparum. Two of the genotypic molecular markers displayed different allelic variants between the two samples. This difference could imply infection multiplicity of the mother during the pregnancy, possibly harbouring more than one isolate, only one of them being transmitted to the newborn while the other persisting in the mother’s blood. Because of the increasing number of pregnant women coming from endemic areas for malaria, an accurate anamnesis of infant’s mother, and the inclusion of Plasmodium spp. research into TORCH screenings for mother-infant pair at birth, aiming at reducing morbidity and mortality associated to the disease might be suitable.

Discordant clinical outcomes of congenital Zika virus infection in twin pregnancies

Congenital Zika syndrome is an emergent cause of a congenital infectious disorder, resulting in severe damage to the central nervous system and microcephaly. Despite advances in understanding the pathophysiology of the disease, we still do not know all the mechanisms enrolled in the vertical transmission of the virus. As has already been reported in other types of congenital infectious disorders in dizygotic twin pregnancies, it is possible that the virus affects only one of the fetuses. In this article, we report on two cases of twin pregnancies exposed to the Zika virus, but with only one of the fetuses affected with microcephaly and brain damage. This indicates the urgent need for more studies regarding the pathophysiology of viral infection and the mechanisms involved in the natural protection against the virus.

Twin pregnancy as a risk factor for mother-to-child transmission of HIV-1: trends over 20 years

OBJECTIVE

We investigated whether twin pregnancies were at increased risk of mother-to-child HIV-1 transmission (MTCT), in comparison with singletons.

METHODS

Among HIV-1 infected women enrolled in the French Perinatal HIV Cohort (n = 9262), we studied the association between twin deliveries and MTCT rate according to three time periods (pre-1994, 1994-1996, 1997-2004) and the effect of birth order. The mother was considered to have transmitted if at least one of the twins was infected. Univariate and multivariate analyses of risk factors for MTCT were performed for deliveries in the periods up to 1996.

RESULTS

Overall, 2.1% (192/9262) of all the deliveries were twins. The rate of prematurity was greater in twins than in singletons (54% and 13%, respectively). Up to 1996 the rate of MTCT of HIV-1 was 28.3% (15/53) in twin pregnancies, versus 13.5% (414/3077) in singletons [odds ratio (OR), 2.5; 95% confidence interval (CI), 1.4-4.7; P = 0.002; adjusted OR, 2.3: 95% CI, 1.1-2.3; P = 0.03). In the period from 1997 to 2003, MTCT was low and did not differ between twins (1.0%) and singletons (1.8%; P = 1.0). Overall, the transmission rate for the first-born child was threefold that for the second-born child (14/164, 8.5% versus 4/164, 2.4%; P = 0.008).

CONCLUSION

Twin pregnancies were at increased risk of transmission, but in the era of HAART this risk was reduced for twins, as well as singletons. Management of multiple pregnancies should take into account the risks of premature rupture of the membranes and preterm delivery.

Mother to child transmission of hepatitis C virus: prospective study of risk factors and timing of infection in children born to women seronegative for HIV-1. Tuscany Study Group on Hepatitis C Virus Infection

OBJECTIVE

To determine the risk factors for and timing of vertical transmission of hepatitis C virus in women who are not infected with HIV-1.

DESIGN

Follow up for a median of 28 (range 24-38) months of babies born to women with antibodies to hepatitis C virus but not HIV-1.

SUBJECTS

442 mothers and babies, of whom 403 completed the study.

MAIN OUTCOME MEASURES

Presence of antibodies to hepatitis C virus and viral RNA and alanine aminotransferase activity in babies. Presence of viral RNA, method of infection with hepatitis C, method of delivery, and type of infant feeding in mothers.

RESULTS

13 of the 403 children had acquired hepatitis C virus infection at the end of follow up. All these children were born to women positive for hepatitis C virus RNA; none of the 128 RNA negative mothers passed on the infection (difference 5%, 95% confidence interval 2% to 7%). 6 children had viral RNA immediately after birth. 111 women had used intravenous drugs and 20 had received blood transfusions. 11 of the infected children were born to these women compared with 2 to the 144 with no known risk factor (difference 7%, 2% to 12%).

CONCLUSIONS

This study suggests that in women not infected with HIV only those with hepatitis C virus RNA are at risk of infecting their babies. Transmission does seem to occur in utero, and the rate of transmission is higher in women who have had blood transfusions or used intravenous drugs than in women with no known risk factor for infection.

Mother to child transmission of hepatitis C virus: prospective study of risk factors and timing of infection in children born to women seronegative for HIV-1. Tuscany Study Group on Hepatitis C Virus Infection

OBJECTIVE

To determine the risk factors for and timing of vertical transmission of hepatitis C virus in women who are not infected with HIV-1.

DESIGN

Follow up for a median of 28 (range 24-38) months of babies born to women with antibodies to hepatitis C virus but not HIV-1.

SUBJECTS

442 mothers and babies, of whom 403 completed the study.

MAIN OUTCOME MEASURES

Presence of antibodies to hepatitis C virus and viral RNA and alanine aminotransferase activity in babies. Presence of viral RNA, method of infection with hepatitis C, method of delivery, and type of infant feeding in mothers.

RESULTS

13 of the 403 children had acquired hepatitis C virus infection at the end of follow up. All these children were born to women positive for hepatitis C virus RNA; none of the 128 RNA negative mothers passed on the infection (difference 5%, 95% confidence interval 2% to 7%). 6 children had viral RNA immediately after birth. 111 women had used intravenous drugs and 20 had received blood transfusions. 11 of the infected children were born to these women compared with 2 to the 144 with no known risk factor (difference 7%, 2% to 12%).

CONCLUSIONS

This study suggests that in women not infected with HIV only those with hepatitis C virus RNA are at risk of infecting their babies. Transmission does seem to occur in utero, and the rate of transmission is higher in women who have had blood transfusions or used intravenous drugs than in women with no known risk factor for infection.

HIV in the neonate

Mother-to-infant transmission of human immunodeficiency virus (HIV) is a worldwide problem. Between 7 and 40% of infants born to HIV-positive mothers become infected. The prognosis of these infants is poor, with most developing early and rapidly progressive disease. A number of advances in diagnosis and therapy offer opportunities to reduce the rate of vertical transmission and to improve the outlook of infected infants. Antiretroviral therapy during pregnancy and the neonatal period can markedly reduce the risk of mother-to-infant transmission. Recognition that 50% or more of infections are transmitted peripartum offers scope to further reduce the rate of transmission. However there is currently no consensus on the optimal management of pregnancy in HIV-infected women, and there is an urgent need for large randomized controlled trials. The development of polymerase chain reaction and p24 antigen assays has greatly facilitated the diagnosis of neonatal HIV infection, thereby enabling earlier supportive and anti-retroviral therapy. The place of zidovudine in paediatric HIV infection is now well-established, but the future will undoubtedly bring combination anti-retroviral therapy. Optimism about the prospects for developments in the prevention and treatment of paediatric acquired immunodeficiency syndrome must be tempered by the fact that the majority of cases occur in countries where patients have little or no access to medical care.

Vertical transmission of human immunodeficiency virus type 1: insights from studies of multiple pregnancies

Because twins share an in utero environment and genetic relationships, similarities and differences between them can provide insight into the epidemiology and natural history of infectious agents, especially human immunodeficiency virus type 1 (HIV-1). Three projects were summarized: HIV-1 transmission and AIDS-free survival in The International Registry of HIV-Exposed Twins; cloning and sequencing of HIV-1 proviral sequences in two sets of identical twins; and transmission and natural history of ovine lentivirus (OvLV) in twin lambs. Both HIV-1 and OvLV transmission were increased for first-born twins. With HIV-1, progression to AIDS appeared independent of zygosity. Development of pneumonitis with experimental OvLV infection was highly concordant in monozygotic lambs. Finally, the identical infected twins in one set had intermingling of each infant's HIV-1 quasispecies, whereas in the second set each twin had its own distinct cluster of quasispecies around a maternal sequence. The studies indicate that most transmission occurs during labor or delivery, and they suggest that immunogenetics may not affect susceptibility to different HIV-1 quasispecies but may affect the manifestations of specific opportunistic diseases.

Human immunodeficiency virus type 1 infection, clinical trials and ethics in paediatrics

Children are not little adults and questions regarding their treatment must be directly addressed to children. Phase I and II trials should closely follow those in adults, integrated by separate studies in infants. Phase III trials should be carried out in a parallel fashion, flexible enough to be modifiable according to results from larger studies in adults. On condition that study designs are ethically impeccable and are respectful of the intrinsic social weakness of children, as many children as possible should enter clinical trials to offer wide access to drugs and ensure that questions are addressed as rapidly and efficiently as possible.

Maternal clinical factors influencing HIV-1 transmission

The complex puzzle of maternal factors involved in mother-to-child human immunodeficiency virus type 1 (HIV-1) transmission is being put together. The risk of perinatal infection increases with mother's disease progression, but it remains stable in women seroconverting to HIV-1 during pregnancy and in consecutive pregnancies. Thus, transmission correlates with the HIV-1 progression rather than the duration of infection in the mother. Nutritional alterations such as vitamin A deficiency may also have a significant impact, whereas geographic origin and mode of maternal infection are of no influence. Placenta membrane inflammation and concurrent sexually transmitted diseases are other significant covariates. The rate of transmission appears directly correlated with maternal age and inversely with length of gestation. A protective effect of caesarean section has been reported in some observational studies but, being controversial, these results need to be corroborated by randomized trials.

Birth order, delivery route, and concordance in the transmission of human immunodeficiency virus type 1 from mothers to twins. International Registry of HIV-Exposed Twins

BACKGROUND

We evaluated data from prospectively identified twins to understand better the mechanisms and covariates of mother-to-infant transmission of human immunodeficiency virus (HIV).

METHODS

Using data obtained from an international collaboration and multivariate quasilikelihood modeling, we assessed concordance, birth order, route of delivery, and other factors for HIV infection in 115 prospectively studied twin pairs born to HIV-infected women. Actuarial methods were used to evaluate overall survival and survival free of acquired immunodeficiency syndrome for HIV-infected twins.

RESULTS

Infection with HIV occurred in 35% of vaginally delivered firstborn (A) twins, 16% of cesarean-delivered A twins, 15% of vaginally delivered second-born (B) twins, and 8% of cesarean-delivered B twins. In a multivariate model, the adjusted odds ratios for HIV infection were 11.8 (confidence interval: 3.1 to 45.3) for concordance of infection with the co-twin, 2.8 (confidence interval: 1.6 to 5.0) for A versus B twins, and 2.7 (confidence interval: 1.1 to 6.6) for vaginally delivered versus cesarean-delivered twins. Among A twins, 52% (lower confidence limit: 6%) of the transmission risk was related to vaginal delivery. Comparing vaginally delivered A twins (infants most exposed to vaginal mucus and blood) to cesarean-delivered B twins (infants least exposed), 76% (lower confidence limit: 48%) of the transmission risk was related to vaginal exposure. Infected B twins had slightly reduced Quetelet indexes and more rapid development of illnesses related to acquired immunodeficiency syndrome.

CONCLUSIONS

These results indicate that HIV infection of B twins occurs predominantly in utero, whereas infection of A twins (and, by implication, singletons) occurs predominantly intrapartum. We propose that intrapartum transmission is responsible for the majority of pediatric HIV infections and that reducing exposure to HIV in the birth canal may reduce transmission of the virus from mother to infant.

Mother-to-infant HIV transmission: timing, risk factors and prevention

Identifying when--during pregnancy, delivery or the postnatal period--transmission of human immunodeficiency virus (HIV) from mother to infant usually takes place is critical to the development of methods to prevent maternal-infant transmission. Evidence is reviewed in this paper as to whether transmission occurs prepartum (early or late in gestation), intrapartum, or postpartum with breast feeding. Evidence in support of the notion of prepartum transmission has come from isolation of HIV from aborted fetal organs, comparison of maternal-child viral genotypes and study of neonatal cell-mediated immune responses. Evidence against prepartum transmission is that fewer than half of the children later known to be HIV-infected can be identified by virological tests carried out close to birth. A reduced rate of transmission in infants delivered by Caesarean section, and a reduced risk of transmission to second-born twins delivered vaginally, offers support to the view that intrapartum factors influence the risk of HIV transmission. Transmission through breast feeding can occur if a mother is infected postpartum and seems to pose some additional risk if she is already infected at parturition. The risk of infection increases with the stage of maternal HIV disease, but specific immunological, clinical and viral characteristics need to be investigated further. A clinical trial of zidovudine, used during late pregnancy and delivery and given to the infant at birth, has reported a significant reduction in transmission. Primary prevention of HIV infection in women remains a principal priority.

Epidemiology of HIV infection in children in Italy. The Italian Register for HIV Infection in Children

As of April 1992, 2337 children born to HIV-1-positive mothers were recorded by our multicentre study. Another 131 children were infected by contaminated blood products, while in 5 cases the risk factor remained unknown, as their personal history was lacking. The number of perinatally exposed children increased exponentially from 1981 to 1986, then stabilized. Of these, at last visit 624 were infected (531 P-2, 93 P-1), 463 were P-O and 1195 had seroreverted. Drug addiction continues to be the most frequent maternal risk factor, although infection acquired through sexual contact gradually increased up to 26.5% in 1991. Of the 762 first children identified at birth and older than 15 months of age, 132 (17.3%) acquired infection and seroconverted to HIV. A similar transmission rate was observed in 43 second-born children.

Prognostic factors and survival in children with perinatal HIV-1 infection. The Italian Register for HIV Infections in Children

The signs that may arise after perinatal infection with human immunodeficiency virus type 1 (HIV-1) have been classified by the Centers for Disease Control, but the clinical usefulness of the classification system and the prognostic importance of each disease pattern have not been established. We sought to address these issues by analysing data from the Italian Register for HIV infection in children. We studied 1887 children born to HIV-1-seropositive mothers. 1045 were identified at birth and the others were registered later (median age 4.8 [range 0.4-72] months). HIV-1-associated signs developed in 433 (81.8%) of 529 seropositive infected children at a median age of 5 (0.03-84) months. These signs appeared significantly earlier in the 102 children who died of HIV-1-related illness than in those who are still alive (median 3 [0.03-55] vs 6 [0.03-84] months; p less than 0.001). The cumulative proportion surviving at age 9 years was 49.5% (95% confidence interval 27-65%) and the median survival time was 96.2 months. Separate analysis of the 112 seropositive infected children followed from birth and older than 15 months gave similar results. Hepatomegaly, splenomegaly, lymphadenopathy, parotitis, skin diseases, and recurrent respiratory tract infections formed the mildest disease pattern. Lymphoid interstitial pneumonitis and thrombocytopenia were signs of intermediate disease. By contrast, in multivariate analysis specific secondary infectious diseases, severe bacterial infections, progressive neurological disease, anaemia, and fever were significant and independent negative predictors of survival. Growth failure, persistent oral candidosis, hepatitis, and cardiopathy were associated in univariate analysis with significantly shorter survival. Our findings suggest that the outlook for children with perinatal HIV-1 infection is better than previously thought and that a new clinical staging system of single disease patterns is needed.