Spain registers 52 cases of hepatitis of unknown origin in children

Most cases are in youngsters under six years of age, with a higher proportion of girls. Twenty-two European countries have already reported 555 cases of acute hepatitis of unknown aetiology


Spain has already registered 52 cases of acute hepatitis of unknown origin in children under investigation, which is four more than on 31 August according to data released on 5 October from the National Centre for Epidemiology.

According to the report, the majority of cases are in children under 6 years of age, with a higher proportion of girls. As already stated in other reports from the national Ministry of Health, three children have needed liver transplants and two of those have died.

By region, Madrid is the place where the most cases have been detected (17), ahead of Catalonia (9). They are followed by Galicia (6), the Balearic Islands (5), Andalucía (4), Murcia (3), Castilla-La Mancha (3), Castilla y León (2), the Canary Islands (1), the Valencian Community (1) and Aragón ( 1).

Some 41 cases (82%) resided in municipalities classified as large urban areas, while seven (14%) resided in small urban areas and two cases in non-urban municipalities. Information on the municipality of residence is not available in two cases. The percentage of cases that reside in large urban areas is significantly higher than the proportion of the Spanish population that resides in this type of municipality (70%).

Onset of symptoms

The onset of symptoms of the first case was on 2 January, 2021 and that of the last reported case on 22 September, 2022, this information not known in one case.

The mean age of the cases under investigation was 5 years and the median age was 3 years (range 0 months to 16 years). By sex, 33 cases were girls (63.5%) and 19 boys (36.5%), with a higher proportion of girls being observed, especially in the group from 0 to 5 years old.

Among cases for which information on symptoms is available, the most frequently reported were: malaise (29 cases; 64% of those with information for this symptom), vomiting (30 cases; 60%), fever ( 28 cases; 60%) and abdominal pain (23 cases; 48%). Jaundice was reported in 21 cases (46%), diarrhoea in 16 (33%), respiratory symptoms in 14 (30%), and rash in 10 (22%).

In 15 cases under investigation out of 48 analysed for which results are available, a positive test for adenovirus was obtained. There are only 4 cases in which SARS-CoV-2 has been detected in the pharyngeal swab of 44 cases analysed. In addition, in another 11 cases (out of 20 analysed), antibodies against SARS-CoV-2 have been detected. Of 47 cases in which there is information on vaccination against SARS-CoV-2, 9 cases had received the vaccine against Covid-19.

The report clarifies that there is no increase in cases of severe hepatitis of unknown origin in children aged 0 to 16 years between January and May compared to the same period of the previous five years. .

Neither was a higher incidence of fulminant hepatitis in paediatric patients requiring liver transplantation detected between January and August at the national level, compared to the estimated average for the same period between 2012 and 2021.

Thus, the report clarifies that, unlike what has been observed in the United Kingdom, in Spain to date "no common cause has been found in these cases, nor has an increase above expectations been observed, although the approximations for estimating this increase are not entirely conclusive.”

555 cases in Europe

As of 29 September, 22 European countries have already reported 555 cases of acute hepatitis of unknown aetiology: Spain (52), Austria (6), Belgium (14), Bulgaria (1), Cyprus (2), Denmark (8) , Finland (1), France (10), Greece (20), Ireland (29), Israel (5), Italy (45), Latvia (1), Luxembourg (1), the Netherlands (16), Norway (6 ), Poland (21), Portugal (26), Moldova (1), Serbia (1), Sweden (11), and the United Kingdom (278).

The majority (75.9%) of the cases are five years old or younger. Of 382 cases with available information, 97 (27%) required admission to an intensive care unit (ICU). Of the 359 cases for which this information is available, 23 (7.5%) received a liver transplant.

In total, 435 cases were tested for adenovirus. Of these, 231 (53.1%) tested positive. The positivity rate was highest in whole blood samples (49.8%).

Of the 378 cases that underwent PCR testing for SARS-CoV-2, 39 (10.3%) were positive. Serology results for SARS-CoV-2 are only available for 106 cases, of which 67 (63.2%) were positive. Of the 159 cases with vaccination data against Covid-19, 141 (88.7%) were not vaccinated