While Ebola virus disease (EVD) is on everyone’s mind, ill travelers returning from West Africa are far more likely to have malaria, according to findings from the GeoSentinel Surveillance Network.

“We need to keep common diseases in mind in travelers returning from Guinea, Liberia, and Sierra Leone,” Dr. Davidson H. Hamer, from Boston University in Massachusetts, told Reuters Health by email. “These include malaria, acute diarrhea, and influenza, and other febrile respiratory tract infections. In addition, there is a broad array of other infections that can cause symptoms and signs that overlap with Ebola, including typhoid fever, nontyphoidal salmonellosis, dengue, and many other less common illnesses.”

Fears surrounding the EVD epidemic have sometimes resulted in delayed evaluation and management of non-Ebola-related febrile illnesses among travelers arriving from West Africa, prompting Dr. Hamer and colleagues to provide an evidence base to inform the differential diagnosis of sick travelers from the Ebola epidemic region and improve evaluation and medical management.

They used data from GeoSentinel, a network of 57 specialized travel and tropical medicine clinics on six continents. The database for 2009–2014 included 805 individuals with confirmed or probable diagnoses attributable to travel in Sierra Leone, Liberia, or Guinea.
Systemic febrile illness was the most common syndrome classification (49.2%), followed by acute diarrhea (19.6%), other gastrointestinal symptoms (11.7%), and respiratory illness (6.7%), according to the May 12 Annals of Internal Medicine online report.

The most frequent diagnoses among non-immigrant travelers were malaria (40.3%), acute diarrhea (12.3%), influenza-like illness or upper respiratory tract infection (4.2%), viral syndrome (3.8%), and febrile illness not otherwise specified lasting less than three weeks (3.1%).

Among immigrants from these regions, the most common diagnoses were latent tuberculosis (42.9%), dental caries (31.4%), schistosomiasis (31.4%), strongyloidiasis (17.1%), and giardiasis (14.3%).

Malaria was also the most common diagnosis among children (40.3%), followed by giardiasis, anemia, cutaneous fungal infection, and upper respiratory tract infection.
Only 39% of returning travelers with malaria had received pretravel counseling, the researchers noted.

“Where adequate laboratory capacity exists, ruling out malaria in febrile travelers from West Africa is critical to limiting morbidity and mortality,” they wrote. “In situations where laboratory infrastructure is inadequate or a diagnostic result will be delayed, administration of empirical antimalarial therapy and broad-spectrum antibiotic coverage for bacteremia is imperative and potentially life-saving.”

The authors added, “Patients with a confirmed diagnosis of malaria who are still considered at risk for EVD may continue to require isolation precautions until EVD is excluded. However, those with malaria who improve clinically and defervesce during antimalarial treatment and who do not have signs of concomitant EVD (such as large-volume diarrhea), even if they are at risk for EVD, may come out of isolation unless their clinical status changes within the 21-day Ebola virus incubation period.”