Addressing theFertility needs of HIV-Seropositive Males

Abstract

Venezuelan equine encephalitis (VEE) is an emerging infectious disease in Latin America. Outbreaks have been recorded for decades in countries with enzootic circulation, and the recent implementation of surveillance systems has allowed the detection of additional human cases in countries and areas with previously unknown VEE activity. Clinically, VEE is indistinguishable from dengue and other arboviral diseases and confirmatory diagnosis requires the use of specialized laboratory tests that are difficult to afford in resource-limited regions. Thus, the disease burden of endemic VEE in developing countries remains largely unknown, but recent surveillance suggests that it may represent up to 10% of the dengue burden in neotropical cities, or tens-of-thousands of cases per year throughout Latin America. The potential emergence of epizootic viruses from enzootic progenitors further highlights the need to strengthen surveillance activities, identify mosquito vectors and reservoirs and develop effective strategies to control the disease. In this article, we provide an overview of the current status of endemic VEE that results from spillover of the enzootic cycles, and we discuss public health measures for disease control as well as future avenues for VEE research.

Alphaviruses: Population genetics and determinants of emergence

“…There are no convincing data to indicate differences in human virulence among VEEV strains (Aguilar et al, 2011). Many artificially attenuated VEEV strains have been described, including the TC-83 vaccine strain used for equids (Walton et al, 1972; Walton and Johnson, 1972) and humans (Berge et al, 1961; Pittman et al, 1996).…”

“…Since its isolation in 1938, VEEV has caused several major epizootic/epidemics involving hundreds-of-thousands of human and equine cases (Weaver et al, 2004). Surveillance activities also indicate that endemic VEE, resulting from spillover from the enzootic rodent cycle of VEEV and related VEE complex viruses, also represents a large burden of human disease, possibly tens-of-thousands of cases annually (Aguilar et al, 2011; Forshey et al, 2010; Franck and Johnson, 1970; Quiroz et al, 2009). Endemic VEE has been identified in many tropical and subtropical regions of the Americas, hidden under the “dengue umbrella” due to the nonspecific signs and symptoms that overlap extensively with those of dengue and many other tropical diseases.…”

“…The former results in nearly continuous endemic disease in many parts of Mexico, Central and South America (Aguilar et al, 2011). In nearly every lowland tropical region near forested habitats, endemic VEE is found whenever surveillance including sensitive and specific laboratory diagnostics are undertaken.…”

“…Most persons recover after about one week, but 5–15% of cases, mainly in children, progress to neurologic signs including convulsions, drowsiness, disorientation and sometimes coma, with an overall case-fatality rate of about 0.5%. Although there is a major difference between enzootic and epizootic VEEV strains in pathogenesis for equids (the former produce little apparent disease, and little or no viremia while the latter produce high rates of fatal encephalitis and high viremia levels), there is little or no difference in human pathogenesis between the two (Aguilar et al, 2011). …”

“…5) (Walton and Grayson, 1988; Weaver et al, 2004). Humans regularly become infected from enzootic cycles via direct spillover when they enter enzootic habitats, but enzootic transmission to humans also occurs in cities in Colombia and Peru where enzootic vectors have been collected in and near human habitations (Aguilar et al, 2011). The epizootic/epidemic cycle has been described only for VEEV subtypes IAB, and IC.…”