Editorial Commentary:A Novel Mode of Transmission for Human Enterovirus Infection Is Swimming in Contaminated Seawater: Implications in Public Health and in Epidemiological Surveillance

Abstract

with the potential emergence of new epidemic serotypes [2, 3]. Although the majority of human EV infections remain asymptomatic, these viruses are associated with a large diversity of clinical syndromes, ranging from minor febrile illness to severe and potentially fatal pathologies, including aseptic meningitis, encephalitis, myopericarditis, acute flaccid paralysis, and severe neonatal sepsis-like disease [1, 4]. The primary mode of direct or indirect transmission of EV remains the fecal-oral route [4]. However, other efficient modes of transmission, such as respiratory or eye mucosal routes, have been reported [5, 6]. Patterns such as direct person-to-person contact seem to be important in many outbreaks of EV infection. However, because human EVs are enteric viruses, water-related transmission remains of primary importance for indirect viral transmission and represents a potentially significant human health risk [7, 8]. Consequently, the information regarding the detection of EV in water, such as epidemiological data related to waterborne diseases, is crucial to modern public health survey systems [8]. In this issue of Clinical Infectious Diseases, Begier et al. [9] present an epidemiological and virological analysis of an outbreak of concurrent echovirus 30 (E30) and coxsackievirus Al (CVA1) infections associated with sea swimming among a group of travelers to Mexico in 2004. This study reports, for the first time to our knowledge, an important public health problem: swimming in contaminated seawater as a novel mode of transmission of EVs. Previous studies reported potential transmission of EVs through clams or oysters, drinking water, and recreational hot spring waters but never through contaminated seawater [10-13]. In the study by Begier et al. [9], the authors identified cases of concurrent E30 and CVA1 infections associated with swimming in seawater. They used partial viral capsid protein 1 (VP1) gene analysis to perform direct genotyping identification, which revealed the presence of E30 in CSF samples and the presence of E30 and CVA1 in stool samples [14]. For the 29 symptomatic travelers, the clinical and epidemiological parameters related to this epidemic event were recovered and analyzed; some clinical syndromes were statistically significantly associated with EV contamination through swim-