The west African Ebola virus disease (EVD) outbreak is the largest ever seen in history, with more than 28 000 cases and 11 300 deaths since early 2014. Prior to this outbreak, knowledge about diagnosis and clinical management of EVD was very limited. But gaps in knowledge on EVD were even more marked in the paediatric population.

1 Shah T

Greig J

van der Plas LM

et al. Inpatient signs and symptoms and factors associated with death in children aged 5 years and younger admitted to two Ebola management centres in Sierra Leone, 2014: a retrospective cohort study. One of the main challenges faced was the difference in clinical presentation of the disease in children compared with adults. In their observational study in The Lancet Global Health, Tejshri Shah and colleaguesadd important information to the picture of EVD in children younger than 5 years and the follow-up of their symptoms during the acute phase while admitted to Ebola treatment centres (ETCs). The study provides clinical markers for severity—fever, diarrhoea, and vomiting—that are helpful in future triage, in addition to markers that help identify those likely to have poor outcomes such as hiccuping, bleeding, and confusion. It would have been interesting to understand whether the severity of the clinical presentation or PCR cycle threshold values changed over the course of the outbreak.

1 Shah T

Greig J

van der Plas LM

et al. Inpatient signs and symptoms and factors associated with death in children aged 5 years and younger admitted to two Ebola management centres in Sierra Leone, 2014: a retrospective cohort study. 2 Lado M

Walker NF

Baker P

et al. Clinical features of patients isolated for suspected Ebola virus disease at Connaught Hospital, Freetown, Sierra Leone: a retrospective cohort study. This study builds on important evidence about the absence of fever in many EVD cases (25% of childrenvs 15% of adults) noted in previous reviews of clinical features of Ebola. Those without fever did not meet the WHO case definition for a suspected case, highlighting the need to reassess this definition so as not to miss significant numbers of paediatric cases during a future outbreak.

3 Fitzgerald F

Naveed A

Wing K

et al. Ebola virus disease in children in Sierra Leone: a retrospective study. , 4 Fitzgerald F

Awonuga W

Shah T

Youkee D Ebola response in Sierra Leone: the impact on children. Shah and colleagues' study shows that the majority of children with confusion died. Although the confusional state may represent the encephalitic stage of EVD, the contribution of metabolic causes is not known. Some papers on the clinical features of EVD in children described several cases of hypoglycaemia.It would have been useful to measure the blood glucose concentrations in children in this study to understand the importance of hypoglycaemia in children with confusion and thus to improve the management of patients in ETCs.

Apart from the clinical presentation, there are other factors that make children a special and vulnerable population. One of the most relevant is the source of EVD infection in children, particularly when the parents were not affected. We know that the disease is transmitted through contact with body fluids (blood, vomit, faeces, urine, etc) of EVD patients in the gastrointestinal symptomatic phase and dead affected bodies. The assumption that the transmission of the disease in this population can only come from the parents and household contacts led to many delays in the detection of cases. Many children are looked after by neighbours and relatives and share spaces with other children who may be infected. But the description of those contacts was difficult for children, particularly for those younger than 5 years in whom language is not yet fully developed.

5 National Ebola Response Centre

Sierra Leone Emergency Management Program standard operating procedure for safe, dignified medical burials. Additionally, traditional burials during which children may have been baptised with the water used to wash the dead bodies (many of whom probably died from EVD) were potential sources of infection for children during the beginning of the outbreak when the Safe Medical Burials policywas not yet established.

6 Walker NF

Brown CS

Youkee D

et al. Evaluation of a point-of-care blood test for identification of Ebola virus disease at Ebola holding units, Western Area, Sierra Leone, January to February 2015. All these factors made it very difficult to establish an accurate case definition of EVD in children in the west African outbreak—screening staff were not able to rely on epidemiological links or contact histories as we did with adults. That meant isolating and testing most children who presented to health-care facilities with common symptoms such as fever, diarrhoea, vomiting, distress, or unexplained crying. That may have overstretched health-care facilities attending to children at that time, and exposed many to potential nosocomial transmission of EVD. In the case of Freetown and the western Area of Sierra Leone, the tertiary referral hospital for children had to close for some months while it was refurbished and adapted to meet the preadmission requirement for isolation and testing for EVD. A rapid diagnostic test with high sensitivity and specificity would allow a quick rule-out for polysymptomatic children presenting to such facilities, reducing the need for dedicated EVD bed capacity.

In keeping with our experience, Shah and colleagues' study demonstrates a higher mortality in children presenting earlier to the ETC, which the authors attribute to survivor bias. We observed that those who presented earlier tended to be more likely to have a known high-risk contact than those who presented later. It may therefore be that children with high risk, and therefore high viral load exposure—eg, sibling illness—were brought to health-care facilities earlier.

Another crucial challenge was the management of fluids in children with EVD due to the absence of clinical guidelines for this population. The insertion of cannulas in sick children, mainly those with distress, constituted a high risk procedure in the “red” zone when staffing was very limited (at least in the beginning of the outbreak). It would be helpful to know whether the mortality in children in Shah and colleagues' study changed over time with the introduction of intravenous fluids and the increase in the number of health-care workers, mainly with the availability of EVD survivors to help and support children at ETCs. Their contribution probably made an impact on the outcome of children admitted in those facilities.

In conclusion, this paper presents important evidence about clinical presentations of children with EVD before and during admission that will bring more accuracy to the case definition and follow-up of this special population in a future outbreak. Although more information about management is required, clinical guidelines should be developed to reduce mortality in children due to treatable conditions while affected by EVD.

We declare no competing interests.