Delayed diagnosis of travel-acquired malaria was common among children treated at US hospitals and was linked to a higher risk of severe disease, according to a new study published late last week in Pediatrics.

A team led by researchers at Children’s Hospital of Philadelphia (CHOP) reviewed 171 pediatric malaria cases across nine US hospitals from 2016 through 2023. Approximately one-third of children developed severe malaria, though no deaths occurred. 

Roughly one in four (26%) of pediatric patients had a previous in-person or telephone healthcare encounter in which malaria was not considered or testing was not performed. Among those with a delayed diagnosis, 51% went on to develop severe malaria. 

Most children in the study (73%) had traveled to West Africa, often to visit friends and relatives. “Health care clinicians should have a high level of suspicion for malaria infection in patients who have recently traveled to malaria-endemic regions,” the authors write.

‘You can’t tell who’s got malaria just by symptoms’

Ninety percent of pediatric patients presented with fever, and 66% reported at least one gastrointestinal symptom, including vomiting, abdominal pain, and diarrhea. Other symptoms included chills, cough, headache, fatigue, and muscle aches. Some children did not have a fever when they sought care, including several who were tested only because a travel companion had been diagnosed as having malaria.

For children with a delayed diagnosis, the median time to diagnosis was three days, with delayed diagnoses occurring at similar rates across the nine hospital systems. Before receiving the correct diagnosis, pediatric patients were incorrectly diagnosed with viral illness, strep throat, gastroenteritis, or sinusitis. 

“It’s important to note that you can’t tell who’s got malaria just by symptoms,” said senior study author Audrey R. Odom-John, MD, PhD, chief of the Division of Infectious Diseases at CHOP, said in a news release. 

“Children who come in and are suspected of having malaria essentially have fever, but they can also present with a wide range of symptoms,” she added. They can have cough, they can have tummy symptoms, they can have headache, they can have almost anything. That’s why rapid and precise testing is necessary to confirm these cases.”

Child travelers are more likely than adults to develop severe malaria, and, in this study, the rate of pediatric patients who met the Centers for Disease Control and Prevention criteria for severe malaria (32%) was similar to rates seen in previous research. Children with severe malaria had longer hospital stays and were more likely to require blood transfusions and antibiotic treatment than those with uncomplicated cases. 

Prevention gaps left kids unprotected

The findings also highlighted gaps in malaria prevention. Fewer than half of US-based travelers (46%) sought or received pretravel counseling, and among those prescribed antimalarial prophylaxis, only 11% reported taking it as directed.

Barriers to prevention included difficulty obtaining enough medication for long trips and stopping prophylaxis too early after leaving endemic regions. Preventive medicines must be taken for seven to 28 days after returning from an endemic region, and prior authorization from insurance is often required to get enough medicine for longer trips. 

The findings underscore the ongoing risks malaria poses to children traveling abroad and the importance of recognizing infections quickly. “This work highlights the need for continued effort in the prevention of travel-acquired malaria and the importance of prompt diagnosis in pediatric patients,” write the authors.