Sant Joan de Déu Hospital in Barcelona

On 5 April, the UK National IHR Focal Point informed WHO of an increase in severe myocarditis in neonates associated with enterovirus infection in Wales (UK). Between June 2022 and April 2023, ten hospitalised neonates with a positive PCR for enterovirus were found to have myocarditis. Seven of the ten cases were confirmed to have coxsackievirus B3 or coxsackievirus B4. As of 5 May 2023, one patient remained hospitalised and one patient had died. According to the WHO statement, although enterovirus infections are common in neonates and infants, the reported increase in myocarditis - inflammation of heart muscle tissue - with severe outcome associated with enterovirus infection is unusual.

A phase 2 clinical trial has analysed the safety and efficacy of adding immunotherapy to traditional chemotherapy to treat a subtype of acute lymphoblastic leukaemia in children under one year of age. This subtype of leukaemia, although rare in absolute terms, is the most common in children of this age, and its prognosis in this age group had not improved in recent years. The immunotherapy used, a bispecific antibody that binds to tumour cells on the one hand and T lymphocytes on the other, improved two-year survival from 66% to 93% in treated patients, according to The New England Journal of Medicine (NEJM).

About 58.5% of a baby's microbiota come from various parts of its mother's body, according to a study of the transmission of microbes between mother and child in the first month of life. The research, published in Cell Host & Microbe, is based on samples collected from 120 mother-baby pairs, with material from their nose/throat, saliva, skin, milk, vagina and faeces. It compares babies born by caesarean section and vaginally, and confirms that the reduced transfer of faecal microbes in caesarean births can be partially compensated by other transmission routes, such as breastfeeding.

An international team including researchers from Spain has analysed the level of exchange of microbial strains between different generations (vertical transmission) and between people who share a household or are close contacts (horizontal transmission). The analysis, published in the journal Nature, is based on about 9,700 microbiome samples from the faeces and saliva of people with different lifestyles from countries. According to the research, the transmission of bacteria is more frequent for the mouth microbiome than for the gut microbiome among people living together.   

The establishment of the baby's microbiota occurs around the time of birth, when it receives bacteria directly from the mother. A study in the journal Cell suggests that genes can also be transmitted between them by horizontal transfer, without the need for the passage of these micro-organisms.

Bubble boy syndrome is a very serious condition caused by combined immunodeficiency. It is sometimes caused by certain mutations in the gene that codes for the Artemis protein. A phase I-II clinical trial has tested a gene therapy that adds a correct copy of the gene. The results are published in the journal NEJM.

After the acute phase of SARS-CoV-2 infection, children may develop long covid-19 symptoms. Research published in The Lancet Child and Adolescent Health examines the prevalence of these symptoms, quality of life, number of sick days, absences from school, and psychological and social outcomes in children aged 0-14 years who had been infected with SARS-CoV-2.