Congenital infections in Hong Kong: an overview of TORCH.

Congenital infections refer to a group of perinatal infections that may have similar clinical presentations, including rash and ocular findings. TORCH is the acronym that covers these infections (toxoplasmosis, other [syphilis], rubella, cytomegalovirus, herpes simplex virus). There are, however, other important causes of intrauterine/perinatal infections, including enteroviruses, varicella zoster virus, Zika virus, and parvovirus B19. Intrauterine and perinatal infections are significant causes of fetal and neonatal mortality and important contributors to childhood morbidity. A high index of suspicion for congenital infections and awareness of the prominent features of the most common congenital infections can help to facilitate early diagnosis, tailor appropriate diagnostic evaluation, and if appropriate, initiate early treatments. In the absence of maternal laboratory results diagnostic of intrauterine infections, congenital infections should be suspected in newborns with certain clinical features or combinations of clinical features, including hydrops fetalis, microcephaly, seizures, cataract, hearing loss, congenital heart disease, hepatosplenomegaly, jaundice, or rash. Primary prevention of maternal infections during pregnancy is the cornerstone of prevention of congenital infection. Available resources should focus on the promotion of public health.

Risks for adverse pregnancy outcomes and infections in daycare workers: an overview of current epidemiological evidence and implications for primary prevention.

Childcare providers are overwhelmingly women of childbearing age. Occupational risks in this sector include exposure to biological (infectious) or physical (standing, carrying loads) hazards, many of which are associated with adverse pregnancy outcomes such as children with congenital infections, low birth weight or prematurity. Here, the authors examined literature on pregnancy outcomes and infectious hazards related to employment in daycare settings. Overall, 33 original studies (10 reporting pregnancy issues, 23 focusing on infectious risks) published in 1980-2018 were retained following a Medline search. Pregnancy issues in daycare workers have rarely been studied, and inconsistent risks of spontaneous abortion, congenital malformations and fetal growth retardation have been reported. Literature pertaining to infectious risks in daycare settings is extensive. The risk of a primary cytomegalovirus infection during pregnancy was increased for daycare workers caring for >6 children and younger children, changing diapers ≥3 days/week, not wearing gloves when changing diapers, and having employment in daycare for ≤2 years. Personal factors (nulliparity, ethnicity) were also independent risk factors. Parvovirus B19 (B19V) infections appear to be related to employment in daycare, but also to having one's own children and an increased number of siblings. Consequently, the risk of a primary B19V infection during an outbreak is of most concern among younger nulliparous workers caring for large numbers of young infected children. Since the main occupational hazard is viral infection, feasible prevention strategies include improving workers' awareness, serological monitoring during pregnancy, educating on appropriate preventive measures, and ensuring age-appropriate immunization of children and staff in childcare facilities. Int J Occup Med Environ Health. 2020;33(6):733-56.

Advances in the Development of Antiviral Strategies against Parvovirus B19.

Parvovirus B19 (B19V) is a human pathogenic virus, responsible for an ample range of clinical manifestations. Infections are usually mild, self-limiting, and controlled by the development of a specific immune response, but in many cases clinical situations can be more complex and require therapy. Presently available treatments are only supportive, symptomatic, or unspecific, such as administration of intravenous immunoglobulins, and often of limited efficacy. The development of antiviral strategies against B19V should be considered of highest relevance for increasing the available options for more specific and effective therapeutic treatments. This field of research has been explored in recent years, registering some achievements as well as interesting future perspectives. In addition to immunoglobulins, some compounds have been shown to possess inhibitory activity against B19V. Hydroxyurea is an antiproliferative drug used in the treatment of sickle-cell disease that also possesses inhibitory activity against B19V. The nucleotide analogues Cidofovir and its lipid conjugate Brincidofovir are broad-range antivirals mostly active against dsDNA viruses, which showed an antiviral activity also against B19V. Newly synthesized coumarin derivatives offer possibilities for the development of molecules with antiviral activity. Identification of some flavonoid molecules, with direct inhibitory activity against the viral non-structural (NS) protein, indicates a possible line of development for direct antiviral agents. Continuing research in the field, leading to better knowledge of the viral lifecycle and a precise understanding of virus-cell interactions, will offer novel opportunities for developing more efficient, targeted antiviral agents, which can be translated into available therapeutic options.

Management of an obstetric health care provider with acute parvovirus B19 infection.

We report a case of an obstetrician with acute parvovirus B19 infection and the series of exposed pregnant women. Currently, there are no established guidelines regarding management of an obstetric health care provider with acute parvovirus B19 infection. We propose a management scheme of this clinical scenario.

Saccharomyces cerevisiae-derived virus-like particle parvovirus B19 vaccine elicits binding and neutralizing antibodies in a mouse model for sickle cell disease.

Parvovirus B19 infections are typically mild in healthy individuals, but can be life threatening in individuals with sickle cell disease (SCD). A Saccharomyces cerevisiae-derived B19 VLP vaccine, now in pre-clinical development, is immunogenic in wild type mice when administered with the adjuvant MF59. Because SCD alters the immune response, we evaluated the efficacy of this vaccine in a mouse model for SCD. Vaccinated mice with SCD demonstrated similar binding and neutralizing antibody responses to those of heterozygous littermate controls following a prime-boost-boost regimen. Due to the lack of a mouse parvovirus B19 challenge model, we employed a natural mouse pathogen, Sendai virus, to evaluate SCD respiratory tract responses to infection. Normal mucosal and systemic antibody responses were observed in these mice. Results demonstrate that mice with SCD can respond to a VLP vaccine and to a respiratory virus challenge, encouraging rapid development of the B19 vaccine for patients with SCD.

Severe nonimmune hydrops secondary to parvovirus B-19 infection: Spontaneous reversal in utero and survival of a term infant.

We present a case of intrauterine infection with parvovirus B-19 and accompanying severe nonimmune hydrops at 26 weeks' gestation. The fetus showed progressive recovery on ultrasound. A term infant was delivered with hepatosplenomegaly as the only abnormality.

Parvovirus B19 in pregnancy.

Parvovirus B19 is a common, self-limiting, usually benign childhood virus that causes erythema infectiosum, also known as fifth disease. Acute infection in pregnancy can cause B19 infection in the fetus, leading to nonimmune fetal hydrops or fetal loss, depending on gestational age at the time of infection. Susceptibility to parvovirus B19 infection should be determined in selected pregnant women at high risk for exposure, and counseling should be provided regarding prevention, testing, and treatment options if exposed.

Fifth disease in a small rural community. What are the consequences?

OBJECTIVE: To characterise the implications of an outbreak of human parvovirus in a small community. METHOD: A community survey was conducted over a period of 18 months in a small rural town in Western Australia with a population of approximately 4300 people. Outbreak cases were assessed by the single general practice in the town. Notification of the survey was placed in both the schools and by advertisement in the local paper. Survey questionnaires distributed to community members were returned on a voluntary basis. After 12 months repeat surveys were sent to all adults who had responded to the initial survey. RESULTS: Eighty-eight definite and 14 equivocal cases were identified as part of the outbreak, which occurred between late July 1994 and February 1995. Serological testing which confirmed human parvovirus B19 infection was available for 29% of cases. The highest attack rate was in the 5-9 year age group. One-third of cases were adults and 9% of them developed symptoms lasting longer than 6 months. Transient anaemia almost certainly due to parvovirus infection was identified in one adult women during the course of the outbreak. No pregnant woman suffered any adverse fetal outcome as a result of human parvovirus infection. CONCLUSION: In an outbreak of parvovirus, children will be most commonly affected although adults can develop polyarthralgia/arthritis which may persist for several months and some may suffer transient anaemia. Pregnant women are potentially at risk of the development of fetal hydrops and fetal death, but advice to them can be based on the estimate of a less than 1% risk of adverse fetal outcome due to parvovirus infection.

A rash of exanthems. How they affect children and pregnant women.

BACKGROUND: Viral exanthems are a common problem for children, particularly during preschool years. Many of these infections have a dramatic impact on siblings, parents and other contacts. There may also be particular ramifications for pregnant contacts. OBJECTIVE: To discuss some of the most common viral exanthems affecting children, in terms of the epidemiology, clinical features, diagnosis, and the management of both the patient and the contacts. DISCUSSION: Recommendations are made for measles, rubella, parvovirus and varicella regarding immunisations, use of immunoglobulin, serological diagnosis and management of pregnant contacts.

[Parvovirus B19 infection]. / A infecção pelo parvovirus B19.

In 1975, during blood screening for hepatitis B, Cossart et al. discovered the human parvovirus B19 (B19). It is a small, single strand DNA virus of the Parvoviridae family. This virus is widespread with 40-80% of adults showing evidence of infection. It is found in the respiratory secretions of viraemic patients and direct contact has been suggested as the most likely mode of transmission. Parenteral transmission is common during treatment with clotting-factor concentrates, but rarely occurs during transfusion with single donor products. Although B19 usually causes a self-limited illness, complications of infection can be severe and at times life threatening. In pregnant women, infection can lead to spontaneous abortions and hydrops fetalis and, in patients with haemolytic anaemias or in immunocompromised individuals, can induce aplastic crisis and chronic anaemias. The diagnosis can be made by indirect (testing for B19 antibodies) or direct methods (detecting B19 viremia). There are no vaccines or specific therapy currently available. Contact isolation is recommended for hospitalized patients.

Surto de parvovírus B19 no município de Crissiumal/17ª CRS/ RS, agosto de 2016 / Parvovirus B19 outbreak in the municipality of Crissiumal/17ª CRS/ RS, august 2016

Em 18/08/2016, uma escola infantil notificou à vigilância do município de Crissiumal a ocorrência de vários casos de crianças com febre e exantema. A partir dessa informação, a equipe da vigilância, junto com médico da rede de atenção à saúde, deslocou-se até a escola para realizar avaliação clínica dos casos e fazer a investigação epidemiológica com vistas a confirmar a ocorrência de surto de doença exantemática, identificar a causa e desencadear medidas de controle. (AU)

Safety and immunogenicity of a candidate parvovirus B19 vaccine.

Parvovirus B19 is an important human pathogen causing erythema infectiosum, transient aplastic crisis in individuals with underlying hemolytic disorders and hydropsfetalis. We therefore evaluated a parvovirus B19 virus like particle (VLP) vaccine. The safety and immunogenicity of a 25 µg dose of parvovirus B19 recombinant capsid; 2.5 and 25 µg doses of the recombinant capsid given with MF59; and saline placebo were assessed in healthy adults. Because of 3 unexplained cutaneous events the study was halted after enrollment of 43 subjects and before any subject received their third scheduled dose. The rashes developed 5-9 days after the first or second injection and were seen in one placebo recipient (without an injection site lesion) and two vaccine recipients (with injection site reactions). No clear cause was established. Other safety evaluations revealed mostly injection site reactions that were mild to moderate with an increase in pain in subjects receiving vaccine and MF59. After dose 2 the majority of vaccine recipients developed ELISA and neutralizing antibody to parvovirus B19. Given the possible severe consequences of parvovirus B19 infection, further development of a safe and effective vaccine continues to be important.

[Childhood diseases with exanthema]. / Kinderziekten met vlekjes.

- Due to high vaccination coverage, measles and rubella (German measles) are now rarely seen in the Netherlands, which makes recognition of these diseases difficult. - Measles can also occur in people who have been immunized, as a result of vaccination failure. - Swift recognition of measles and rubella is necessary in order to manage them adequately and to prevent spreading of the disease. - Measles, rubella, and erythema infectiosum ('fifth disease') may result in complications during pregnancy. - Measles, rubella, scarlet fever, erythema infectiosum, and roseola ('sixth disease') can be difficult to differentiate. - In the Netherlands, diagnosis of a patient with measles or rubella, or of more than 1 patient with erythema infectiosum within one institution, must be reported to the local health authority within 1 working day. - Exclusion from school or a day-care facility is not required for any if the diseases discussed.

Occupational hazards for pregnant nurses.

OVERVIEW: Depending on her working environment, specific immunities, and stage of pregnancy, a pregnant nurse may find it difficult to avoid teratogenic and fetotoxic exposures, as well as working conditions that could jeopardize her pregnancy. A clinical review of the occupational hazards faced by pregnant nurses can be useful to the concerned nurse or health care system, as can suggestions on ways to reduce risk and a list of pertinent occupational safety resources.