Hantaviruses and cardiopulmonary syndrome in South America

Highlights

• Hantavirus causing human disease in South America.

• Rodents harboring hantavirus in South America.

• The epidemiologic situation of hantavirus pulmonary syndrome in different countries of South America.

• Aspects of the physiopathology and clinical presentation of hantavirus cardiopulmonary syndrome based on studies performed in South America.

Abstract

Hantavirus (Bunyaviridae) cardiopulmonary syndrome (HCPS) is an emerging health problem in South America due to urban growth and to the expansion of agriculture and cattle-raising areas into ecosystems containing most of the species of Sigmodontinae rodents that act as hantavirus reservoirs. About 4000 HCPS cases have been reported in South America up to 2013, associated with the following hantaviruses: Andes, Anajatuba, Araraquara (ARQV), Paranoá, Bermejo, Castelo dos Sonhos, Juquitiba, Araucária, Laguna Negra, Lechiguanas, Maripa, Oran, Rio Mamore and Tunari. The transmission of hantavirus to man occurs by contact with or through aerosols of excreta and secretions of infected rodents. Person-to-person transmission of hantavirus has also been reported in Argentina and Chile. HCPS courses with a capillary leaking syndrome produced by the hantavirus infecting lung endothelial cells and mostly with a severe inflammatory process associated with a cytokine storm. HCPS starts as a dengue-like acute febrile illness but after about 3 days progresses to respiratory failure and cardiogenic shock, leading to a high fatality rate that reaches 50% for patients infected with ARQV.

Introduction

Hantaviruses are important zoonotic pathogens related to rodents and other small mammals (shrews, moles and bats). When infecting man, hantaviruses can cause severe diseases with high case-fatality rates such as hemorrhagic fever with renal syndrome (HFRS) in Asia and Europe and hantavirus cardiopulmonary syndrome (HCPS) in the Americas. In both syndromes, capillary leakage of intravascular fluid into interstitial tissue leads to respiratory and renal failure and shock (Jonsson et al., 2010). However, a recent comparative analysis of HFRS and HCPS cases has revealed that syndromic names are mostly didactic and, in fact, patients from the Americas also have renal failure and patients from Europe and Asia have respiratory failure. Thus, the worldwide use of the term Hantavirus disease has been recently proposed (Clement et al., 2012; see also chapter X of this Special Issue).

The first case of an American hantavirus producing human disease, a cardiopulmonary syndrome caused by Sin Nombre virus (SNV), was reported in the United States Hughes et al. (1993). Dozens of hantavirus genotypes have been reported since then in the Americas associated with autochthonous rodent species of the subfamily Neotominae, Sigmodontinae and Arvicolinae (Jonsson et al., 2010). In South America, hantavirus reservoirs are Sigmodontinae American rodents that harbor the following viruses associated with human disease: Andes, Maciel, Oran, Lechiguanas, Laguna Negra and Bermejo in Argentina, Andes in Chile, Laguna Negra and Bermejo in Paraguay, Laguna Negra, Tunari and Bermejo in Bolivia, Maripa in French Guyana, Juquitiba, Andes and Lechiguanas in Uruguay, and Araraquara, Juquitiba/Araucária, Castelo dos Sonhos, Laguna Negra and Anajatuba in Brazil (Firth et al., 2012). A map of South America showing hantaviruses associated with disease and their rodent reservoirs is shown in Fig. 1.

Hantavirus disease is an emerging health problem in South America due to urban growth and the expansion of agriculture and cattle-raising areas into ecosystems containing most of the species of Sigmodontinae rodents that act as hantavirus reservoirs (Figueiredo et al., 2009b). The biodiversity of natural ecosystems of South America supports about 500 known species of Sigmodontinae (Mills, 2006, Mills et al., 2007).

The transmission of hantavirus to man occurs mostly by contact with or through aerosols of excreta and secretions of infected rodents (Butler and Peters, 1994), although human-to-human transmission of hantavirus has been reported in Argentina and Chile (Martinez et al., 2005, Padula et al., 1998, Wells et al., 1997).