Development and evaluation of a solid-phase enzyme immunoassay based on Andes hantavirus recombinant nucleoprotein

Hantavirus pulmonary syndrome (HPS) with high mortality rate has been repor ted in five countries in South America. Rapid accurate methods are importan t both for monitoring acute infections and for epidemiological studies. The Andes virus nucleoprotein amino acid sequence has a high identity percenta ge compared with other sequences of this region and has been chosen for the development of diagnostic reagents. Andes nucleoprotein expressed in Esche richia coli was applied as antigen in IgG, IgA and mu-capture IgM enzyme-li nked immunosorbent assays (ELISAs), An evaluation of this reagent was condu cted to establish its usefulness for differential diagnosis of HPS and sero prevalence studies, Samples from 135 reverse transcription (RT)-PCR-confirm ed HPS cases, 77 individuals with other respiratory infections and 957 heal thy inhabitants from endemic and non-endemic areas were analysed, The hanta virus-infected patients had an early and strong IgM, IgG and IgA serum anti body response, in most of the cases as early as 1, 7 and 1 days following o nset of symptoms, respectively. IgM and IgG detection showed a specificity and sensitivity of 100%, Andes-specific IgM antibodies were found in all pa tients in the first available sample, which remained detectable for at leas t 43 days. Specific IgA antibodies were also detected in saliva of patients with acute HPS, The short duration of the disease and the risk for contact s due to person-to-person transmission of Andes virus necessitate the use o f highly sensitive tests which might lead to earlier detection of infected people and improve the treatment and management of patients with HPS.