Human Febrile Illness Caused by Encephalomyocarditis Virus Infection, Peru

Abstract

Etiologic studies of acute febrile disease were conducted in sites across South America, including Cusco and Iquitos, Peru. Patients' clinical signs and symptoms were recorded, and acute-and convalescent-phase serum samples were obtained for serologic examination and virus isolation in Vero E6 and C6/36 cells. Virus isolated in Vero E6 cells was identifi ed as encephalomyocarditis virus (EMCV) by electron microscopy and by subsequent molecular diagnostic testing of samples from 2 febrile patients with nausea, headache, and dyspnea. The virus was recovered from acute-phase serum samples from both case-patients and identifi ed with cardiovirus-specifi c reverse transcription-PCR and sequencing. Serum samples from case-patient 1 showed cardiovirus antibody by immunoglobulin M ELISA (acute phase <8, convalescent phase >1,024) and by neutralization assay (acute phase <10, convalescent phase >1,280). Serum samples from case-patient 2 did not contain antibodies detectable by either assay. Detection of virus in serum strongly supports a role for EMCV in human infection and febrile illness.

Diversity of picornaviruses in rural Bolivia

“…Recent studies have reported EMCV infection in two human cases from Peru (Oberste et al, 2009) and 21 % EMCV seroprevalence among persons sampled in the same area of Peru (Czechowicz et al, 2011). Both cardiovirus species were identified in Bolivia human samples.…”

“…Real-time PCR-positive specimens were confirmed by nested or seminested RT-PCR targeting a portion of the genome encoding the VP1 capsid protein (Tables S3-S8), followed by amplicon sequencing for EV (Table S7; Nix et al, 2006), HPeV (Table S8; Nix et al, 2010), cardiovirus (Oberste et al, 2009), kobuvirus, salivirus and cosavirus. Virus type was determined by comparison of the VP1 amplicon nucleotide sequences with VP1 sequences of the reference strains for each genus by script-driven sequential pairwise comparison using the program Gap (Wisconsin Sequence Analysis Package, v. 11.0, Accelrys).…”

“…RNA was extracted from stool suspensions, as previously described (Nix et al, 2006) and tested for enterovirus, parechovirus, cardiovirus, kobuvirus, salivirus and cosavirus by genus-or genus/species-specific Taqman real-time RT-PCR assays targeting the 59 non-translated region (59NTR) (Kilpatrick et al, 2009;Nix et al, 2008;Oberste et al, 2009) (Table S1). Teschovirus testing was performed by using a 59NTR nested RT-PCR (Zell et al, 2000), with the addition of PCR amplicon sequencing to confirm the identity of the correct-sized PCR product.…”

“…Human parechoviruses (HPeV) have a similar disease spectrum as the EVs, but routine clinical testing is less common despite increasing evidence of a significant disease burden in infants (Harvala et al, 2010). Zoonotic infection with encephalomyocarditis virus (EMCV) has been reported (Oberste et al, 2009) but testing for this virus is rarely performed in human clinical virology laboratories. No routine testing is available for newer human picornaviruses, which include Saffold viruses (SAFV) (Cardiovirus), cosaviruses (CoSV) (also published as 'dekavirus'; Cosavirus) and 'salivirus' (SALV) (also published as 'klassevirus'; Salivirus) (Adams et al, in press;Knowles et al, 2012).…”

Saffold Virus, a Novel Human Cardiovirus with Unknown Pathogenicity

“…In addition, EMCV is known to induce pancreatitis and type I diabetes in rodents. The fact that EMCV infection can also lead to encephalomyelitis, myocarditis, orchitis, and sialodacryoadenitis in rodents (12) and that it has been isolated from two febrile patients (10,40) will help guide further investigations of the relationship of SAFV to disease. Furthermore, epidemiological studies will be important to investigate the relationship between SAFV and type I diabetes.…”