South American hemorrhagic fever

SAHF is formally defined as an acute systemic viral infection characterized by a marked tendency toward bleeding and circulatory collapse, placing it within the broader category of American viral hemorrhagic fevers ^[1]. The etiologic agents are primarily New World lineages of arenaviruses that require detailed exposure history assessment for accurate identification ^[2]. While broadly classified as severe human diseases, they remain distinct from other regional hemorrhagic syndromes due to their specific viral families and host associations ^[1].

Clinical presentation centers on rapid onset of systemic involvement accompanied by significant hemorrhagic diathesis and hemodynamic instability ^[1]. Affected individuals face serious morbidity and notably elevated case-fatality ratios, underscoring the critical nature of these infections ^[3]. Comprehensive reviews of pathogenesis, diagnostic markers, and pathological findings have been compiled to aid healthcare providers in recognizing and managing suspected cases ^[2].

The geographic distribution of SAHF viruses is fundamentally restricted by the ranges of their natural reservoirs or arthropod vectors, confining endemic areas to specific parts of the Americas ^[1]. Within these localized zones, the diseases maintain a consistent presence alongside other regional hemorrhagic syndromes ^[1]. Although human cases are uncommon, they represent a persistent public health concern due to the severe nature of the underlying infections ^[1].

Human infection occurs predominantly through zoonotic spillover events linked to contact with infected rodent populations or their environmental excreta ^[1][3]. The spatial ecology of each virus dictates transmission patterns, as viral circulation remains tightly coupled to reservoir species distributions ^[1]. Additionally, secondary spread within healthcare environments poses a recognized threat, necessitating rigorous barrier precautions during patient care ^[1].

Preventive approaches focus on the identification and potential emergency use of candidate therapies and vaccine platforms that have shown benefit in nonhuman primate and human evaluations ^[2]. Because licensed medical countermeasures remain limited, readiness depends on accessing these investigational resources through established clinical networks ^[2]. Guidance documents and authoritative literature links are recommended to facilitate rapid review when managing suspected exposures ^[2].

1. 1Bausch DG et al. Viral hemorrhagic fevers including hantavirus pulmonary syndrome in the Americas. Clin Lab Med. 2002 Dec. PMID: 12489291. doi: 10.1016/s0272-2712(02)00019-7.PubMed: https://pubmed.ncbi.nlm.nih.gov/12489291/
2. 2Frank MG et al. South American Hemorrhagic Fevers: A summary for clinicians. Int J Infect Dis. 2021 Apr. PMID: 33610781. doi: 10.1016/j.ijid.2021.02.046.PubMed: https://pubmed.ncbi.nlm.nih.gov/33610781/
3. 3Doyle TJ et al. Viral hemorrhagic fevers and hantavirus infections in the Americas. Infect Dis Clin North Am. 1998 Mar. PMID: 9494832. doi: 10.1016/s0891-5520(05)70411-6.PubMed: https://pubmed.ncbi.nlm.nih.gov/9494832/
4. 4Carneiro SC et al. Viral exanthems in the tropics. Clin Dermatol. 2007 Mar-Apr. PMID: 17350501. doi: 10.1016/j.clindermatol.2006.05.009.PubMed: https://pubmed.ncbi.nlm.nih.gov/17350501/