Paediatric Neurology
John W. Scadding, Nicholas A. Losseff in Clinical Neurology, 2011
Brain MRI, particularly in children with severe learning disability, may provide valuable diagnostic information through the identification of forms of cerebral dysgenesis or other structural abnormalities. It may also suggest exposure to in-utero infections or an underlying metabolic disorder. Positive findings are more likely in the presence of a motor disorder, abnormal head size, epilepsy or neuro-cutaneous markers. Congenital infection refers to any viral infection sustained in pregnancy, but those most commonly recognized include herpes, rubella, toxoplasmosis and cytomegalovirus (CMV). Although there may be suggestive features on neuroimaging, these require confirmation with serology and this may be difficult or impossible outside the neonatal period. Exposure to toxins such as alcohol or drugs (both prescribed medicines and substances of abuse) puts the fetus at increased risk of an adverse outcome.
Epstein—Barr Virus and CNS Infections
Sunit K. Singh, Daniel Růžek in Neuroviral Infections, 2013
Given the high incidence of all herpesvirus infections (except HHV-8 infection) and the biologic phenomenon of latency, the ubiquity of these viruses is apparent worldwide (Prober 2005). In general, HSV-1 infections begin in infancy and more than 50% of young adults have been infected. Infections caused by HSV-2 start with the onset of sexual activity, and an estimated 5% to 25% of adult people, depending on different countries, have contracted infection. CMV is the most common cause of congenital infection, with 1% of all newborns infected; postnatal infections begin to occur within the first few weeks of life, and by early adulthood, more than 50% of the population is seropositive. Before the development of a vaccine for VZV, chickenpox (the clinical manifestation of the primary infection with VZV) occurred in virtually all people by late childhood; the epidemiology of infection has been changing since the introduction of vaccination (Oxman et al. 2005).
A Case of Toxoplasmosis in Pregnancy
Meera Chand, John Holton in Case Studies in Infection Control, 2018
Before birth, foetal ultrasound scans demonstrating hydrocephalus, intracranial calcification, or hyperechoic mesentery should prompt testing for congenital toxoplasmosis. Foetal magnetic resonance imaging (MRI) has been used to confirm congenital infection (Figure 22.3). Features of infection that may be evident at birth are myriad and include microcephaly, encephalitis, seizures, cerebellar signs, strabismus, rash, diarrhoea, hypothermia, jaundice, lymphadenopathy, pneumonitis, hepatosplenomegaly, anaemia, and thrombocytopenia. None of the symptoms and signs of congenital toxoplasmosis are pathognomonic and differential diagnoses such as cytomegalovirus (CMV) and rubella should be considered. Miscarriage and stillbirth may result from foetal infection. Epilepsy, psychomotor retardation, developmental delay, sensorineural deafness, and blindness may only present later in life, sometimes years after birth. Prospective studies suggest that up to 70% of untreated infected children have retinal lesions detected in the first 10 years of life and about 40% of those treated may experience recurrences of chorioretinitis after this period of time.
Congenital cytomegalovirus infection: epidemiology, prediction, diagnosis, and emerging treatment options for symptomatic infants
Published in Expert Opinion on Orphan Drugs, 2020
Nobuhiko Nagano, Ichiro Morioka
In some case of symptomatic infants, anti-viral treatments with IV GCV or oral VGCV, which are started from the neonatal period, have improved hearing and neurological prognosis. Therefore, if symptomatic infants with congenital infection are diagnosed, they should be consulted with doctors who specialize in neonatal or pediatric infection and should be considered to undergo treatments. However, GCV and VGCV are still off-label drugs for congenital CMV infection worldwide, because there are concerns about its safety during the treatment (myelosuppression, especially neutropenia that occurs at high rates). Long-term influences with fertility and carcinogenicity, which have been demonstrated in animal toxic experiments, have not yet been addressed in humans. The selection of infants to be treated must be done carefully. There is no established evidence for starting treatment after the neonatal period. Moreover, it should be remembered that there are cases where the effectiveness is remarkable, but treatment does not show an effect or hearing is worse even after receiving the treatment. At present, this treatment should be performed with a well-informed consent from the parents.
Immunogenicity and protection efficacy of enhanced fitness recombinant Salmonella Typhi monovalent and bivalent vaccine strains against acute toxoplasmosis
Published in Pathogens and Global Health, 2021
Fei-Kean Loh, Sheila Nathan, Sek-Chuen Chow, Chee-Mun Fang
It is estimated that one-third of the global human population has been exposed to Toxoplasma gondii [1], an opportunistic intracellular protozoan which stays active as tachyzoites but converts to bradyzoites in response to stress [2]. The parasite replicates sexually within the guts of feline families and the oocysts are excreted to the environment. The oocysts are then ingested and usually transmitted through food sources between the definitive hosts and intermediate hosts which include almost all mammals [2]. Most T. gondii infections are asymptomatic as the parasite is suppressed by effective host immune control. However, the tissue cysts can recrudesce in immunocompromised hosts and cause diverse complications. For instance, AIDS/HIV patients have an increased frequency of toxoplasma encephalitis [3]. In pregnant women, T. gondii may transmit across the placenta and cause miscarriage of the fetus. Infants with congenital infection have been diagnosed with manifestations including chorioretinitis, calcification and hydrocephalus [4]. Meta-analyses have also deduced positive correlation between T. gondii seropositivity and psychotic symptoms such as schizophrenia and bipolar disorder [5,6]. To date, there is only one live attenuated vaccine developed from the T. gondii S48 strain, Toxovax, mainly used to prevent sheep and goat abortions in United Kingdom, New Zealand, France and Ireland. All the drugs used in clinical practice are solely active against tachyzoites and are not able to clear cysts formed during chronic infection [7].
Antenatal Cytomegalovirus Infection Screening Results of 32,188 Patients in a Tertiary Referral Center: A Retrospective Cohort Study
Published in Fetal and Pediatric Pathology, 2019
Yasemin Sert, A. Seval Ozgu-Erdinc, Sibel Saygan, Yaprak Engin Ustun
Fetal transmission during pregnancy varies according to gestational age and primary- non-primary infection status. In the first trimester, transplacental transmission of CMV virus to the fetus is observed about 36%–45%, while 10% of babies are symptomatic [20]. The transmission rate increases to 24%–75% with primary infection, whereas it is 1%–2.2% for non-primary infection [1,2,4]. Although recurrent infection is less common and usually mild if compared with primary infection, it can present with severe congenital infection [21]. 10%–15% of infants who are infected will have major symptoms, such as microcephaly, hepatosplenomegaly, chorioretinitis and pancytopenia (and related symptoms including petechiae, anemia, jaundice and recurrent opportunistic infections) and 20%–30% of infected infants will be faced with severe hepatic dysfunction, bacterial sepsis and coagulation defects, which may finally cause mortality [22,23]. Most infected infants, which is about 85%–90%, will have no symptoms at birth but still have a 5%–15% risk of developing neurological sequelae in the future [24,25].
Related Knowledge Centers
- Childbirth
- Fetus
- Embryo
- Infection
- Pregnancy
- Pathogenic Bacteria
- Viral Disease
- Pathogen Transmission
- Pre-Existing Disease In Pregnancy
- Mathematical Modelling of Infectious Diseases