CCHF in Spain: Geographic Dynamics, Nosocomial Spread
Amesh A. Adalja, MD, FACP, FACEP, FIDSA, July 14, 2017
Crimean Congo hemorrhagic fever (CCHF), a select agent, is a tickborne viral hemorrhagic fever (VHF) that is widespread over many parts of the world. In Europe, the virus has generally been believed to be restricted to the southeastern parts of the continent. A new report in the New England Journal of Medicine proves that this geographic restriction no longer holds, as 2 autochthonous cases were identified in Spain.
Index Case and Nosocomial Spread
The index case was a 62-year-old male with no foreign travel history who reported a tick bite while in the province of Avila; he was hospitalized with fever, abdominal pain, malaise, and nausea. He subsequently developed hemorrhagic complications and progressed to fulminant disease and eventual death with multi-organ failure. CCHF was not suspected in this patient during his course of illness.
The second case was a nurse who assisted with endotracheal intubation and central venous catheterization of the index case. She had direct contact with the patient’s blood, though no puncture occurred. Fever, asthenia, and arthro-myalgias occurred 4 days later. CCHF was considered on the 4th day of illness based on her clinical course, which by then included petechiae, thrombocytopenia, transaminase elevation, and vaginal bleeding; ribavirin therapy was implemented. The patient did have hemorrhagic manifestations as well as ribavirin-induced hemolytic anemia. She was hospitalized for approximately 20 days but survived.
Of note, CCHF was only suspected (and confirmed) as the etiology after the 2nd case presented.
Because of the risk of further cases, contact tracing was undertaken, and 437 contacts were identified. Contacts were asked to measure their temperature twice daily for 14 days. No further cases were identified, though serologic testing was not performed to identify asymptomatic cases.
2010 Tick Isolation
The virus isolated from both patients was consistent with a viral strain that had been found in Hyalomma ticks from a province neighboring Avila. The strain is from African lineage 3 and not consistent with Eastern European strains, leading to the hypothesis that the source was infected ticks carried to Spain from Morocco through the livestock trade, infected animals, or some other mechanism.
This case illustrates an important point about emerging infectious diseases: Geographic restrictions are not ironclad and having situational awareness of such elements of disease transmission (such as vector biology with CCHF) is necessary. These cases are the first described, but others may have occurred unrecognized in Spain. The cases also highlight the risk of nosocomial spread of VHFs--as has been seen with Lassa and Ebola--when healthcare providers are dealing with a critically ill patient with an illness of unknown etiology. It will be important to further delineate the geographic reach of CCHF in light of the Spanish experience.
Negredo A, de la Calle-Prieto F, Palencia-Herrejón E, et al. Autochthonous Crimean-Congo hemorrhagic fever in Spain. N Engl J Med 2017;377(2):154-161.