Role of Seaports and Imported Rats in Seoul Hantavirus Circulation, Africa
Résumé
Seoul orthohantavirus (SEOV) is not considered a major public health threat on the continent of Africa. However, Africa is exposed to rodentborne SEOV introduction events through maritime traffic after exponential growth of trade with the rest of the world. Serologic studies have already detected hantavirus antibodies in human populations, and recent investigations have confirmed circulation of hantavirus, including SEOV, in rat populations. Thus, SEOV is a possible emerging zoonotic risk in Africa. Moreover, the range of SEOV could rapidly expand, and transmission to humans could increase because of host switching from the usual brown rat (Rattus norvegicus) species, which is currently invading Africa, to the more widely installed black rat (R. rattus) species. Because of rapid economic development, environmental and climatic changes, and increased international trade, strengthened surveillance is urgently needed to prevent SEOV dissemination among humans in Africa.
Rodents are widespread, opportunistic, and competent host reservoirs involved in the maintenance, circulation, and transmission of a wide panel of zoonotic pathogens (1). Rodent-related zoonoses cause up to 400 million human infections worldwide each year (1,2). Among zoonotic pathogens, hantaviruses (order Bunyavirales, family Hantaviridae, genus Orthohantavirus) are among agents considered most likely to emerge and have a global public health impact (3).
Hantaviruses are enveloped, negative, single-stranded RNA viruses with a tripartite genome comprised of large, medium, and small segments. Transmitted to humans via inhalation of aerosolized virus in contaminated rodent urine and feces, hantaviruses can cause hemorrhagic fever with renal syndrome (HFRS) or hantavirus pulmonary syndrome (4). Hantaviruses are generally carried by a rodent species host, and geographic distribution of the host can determine the area in which the associated disease occurs among humans. From this perspective, Seoul orthohantavirus (SEOV), identified in South Korea in 1982, deserves special attention because its cosmopolitan host, the Norwegian rat (Rattus norvegicus), also known as the brown rat, has been dispersed worldwide, resulting in a global distribution of the virus today (5). Detection of SEOV is often considered anecdotal and speculated to be driven by sporadic introduction of infected brown rats via transportation but also by pet or laboratory rats (6,7). Diagnosing SEOV in humans remains a challenge due to milder and atypical HFRS pathology (8). However, mild symptoms can progress to acute renal disease associated with HFRS, in which patients experience low blood pressure, acute shock, and acute kidney failure, and the case-fatality rate is ≈1% (9).
Domaines
Sciences du Vivant [q-bio]
Origine : Fichiers produits par l'(les) auteur(s)
