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We conducted a double-blind, placebo-controlled clinical trial to evaluate the efficacy of intravenous methylprednisolone for hantavirus cardiopulmonary syndrome in Chile between 2003 and 2010. Sixty of 66 enrollees had hantavirus confirmed. We observed no significant difference in primary efficacy or safety outcomes between the groups.Background. Andes virus (ANDV)–related hantavirus cardiopulmonary syndrome (HCPS) has a 35% case fatality rate in Chile and no specific treatment. In an immunomodulatory approach, we evaluated the efficacy of intravenous methylprednisolone for HCPS treatment, through a parallel-group, placebo-controlled clinical trial.Methods. Patients aged >2 years, with confirmed or suspected HCPS in cardiopulmonary stage, admitted to any of 13 study sites in Chile, were randomized by study center in blocks of 4 with a 1:1 allocation and assigned through sequentially numbered envelopes to receive placebo or methylprednisolone 16 mg/kg/day (≤1000 mg) for 3 days. All personnel remained blinded except the local pharmacist. Infection was confirmed by immunoglobulin M antibodies or ANDV RNA in blood. The composite primary endpoint was death, partial pressure of arterial oxygen/fraction of inspired oxygen ratio ≤55, cardiac index ≤2.2, or ventricular tachycardia or fibrillation within 28 days. Safety endpoints included the number of serious adverse events (SAEs) and quantification of viral RNA in blood. Analysis was by intention to treat.Results. Infection was confirmed in 60 of 66 (91%) enrollees. Fifteen of 30 placebo-treated patients and 11 of 30 methylprednisolone-treated patients progressed to the primary endpoint (P = .43). We observed no significant difference in mortality between treatment groups (P = .41). There was a trend toward more severe disease in placebo recipients at entry. More subjects in the placebo group experienced SAEs (P = .02). There were no SAEs clearly related to methylprednisolone administration, and methylprednisolone did not increase viral load.Conclusions. Although methylprednisolone appears to be safe, it did not provide significant clinical benefit to patients. Our results do not support the use of methylprednisolone for HCPS.Clinical Trials Registration. NCT00128180. [ABSTRACT FROM AUTHOR]

Background. Andes virus (ANDV) infection, which has a case fatality rate of 37% in Chile, often occurs in household clusters and may be transmitted from person to person. Methods. To determine the incidence and risk factors for additional household cases, we conducted a prospective study among recent household contacts of persons with hantavirus cardiopulmonary syndrome (HCPS) in Chile, including testing of serum for anti-hantavirus antibodies and blood cells for ANDV RNA by reversetranscription polymerase chain reaction (RT-PCR). Results. We enrolled 76 index case patients and 476 household contacts, of whom 16 (3.4%) developed HCPS; 32.6% of 92 cases occurred in household clusters. The risk of HCPS was 17.6% among sex partners of index case patients, versus 1.2% among other household contacts (P < .001). Person-to-person transmission was definite in 3, probable in 9, and possible in 2 of the 16 additional household case patients. We detected ANDV RNA by RTPCR in peripheral blood cells 5-15 days before the onset of symptoms or the appearance of anti-hantavirus antibodies. Conclusions. In recent household contacts of persons with HCPS in Chile, the risk of HCPS was greatest among sex partners. Among the household contacts who developed HCPS, viremia preceded the onset of symptoms and the appearance of anti-hantavirus antibodies by up to 2 weeks. [ABSTRACT FROM AUTHOR]

Escherichia coli that exhibit the aggregative pattern of adherence to HEp-2 cells (entero adherent-aggregative E. coli [EA-AggEC]) have been epidemiologically incriminated as a causeof diarrhea. We undertook a preliminary microbiological and pathogenetic characterization of 42 isolates of this putative pathogen. The strains were negative by tests with DNA probes for enteropathogenic, enterotoxigenic, entero invasive, and entero-hemorrhagic E. coli and, by serotype, did not fit these categories. Thirty-nine of 42 strains had a 55–65-megadalton plasmid; many shared DNA homology. With one representative strain, plasmid transfer was accompanied by transfer of smooth lipopolysaccharide, fimbriae expression, and the aggregative property. EA-AggEC caused characteristic lesions in rabbit and rat ileal loops. The intestinal lesions and (Shiga-like) limb paralysis and death in rabbits inoculated with live organisms suggest toxin involvement; assays for Shiga-like toxins were negative. These preliminary results support the contention that EA-AggEC may represent a distinct category of diarrheagenic E. coli. [ABSTRACT FROM PUBLISHER]

In a prospective study, all patients admitted to a unit for convalescing newborns on an infant-toddler ward between January and April 1985 were tested every other day for rotavirus (RV)excretion by using an enzyme-linked immunosorbent assay. RNA electrophoresis of the RV strains identified in this population were analyzed to determine whether specific strains of virus were associated with infections in newborns. RV strains infecting older, symptomatic children from the infant-toddler ward were used for comparison. Among the 39 patients enrolled in the study, RV was detected in the stools of 13 (33%), 11 (86%) of whom were asymptomatic. Three different electropherotypes were seen among the newborns who were RV positive; these electropherotypes were identical to those identified in older children with community-acquired diarrhea and nosocomial-acquired diarrhea who were hospitalized on the infant-toddler ward during the same study period. Each of the three strains was first identified in the general ward and subsequently detected in the room with newborns within three to six days. We failed to identify a particular strain that exclusively infected newborns. [ABSTRACT FROM PUBLISHER]

The epidemiologic significance of enteroaggregative Escherichia coli(EAggEC) as a diarrheal pathogen has only recently come under study. Although EAggEC has been associated with persistent diarrhea in infants in some developing countries, additional studies are clearly needed. Until now, the only means of identifying EAggEC strains has been the cumbersome HEp-2 cell adhesion assay. The isolation and cloning of a 1-kilobase fragment from the plasmid of EAggEC strain 17–2 is described. This probe is 89% sensitive and 99% specific for EAggEC identification. Thus, this probe should greatly facilitate epidemiologic studies assessing the importance of EAggEC as a diarrheal pathogen. [ABSTRACT FROM PUBLISHER]

The proportion of diarrheal illnesses of unknown origin that were associated with small round virus (SRV, 23-38 nm) particles among children <2 years old attending an outpatient clinic in Baltimore was determined. During a 9-month period, stool specimens from 188 patients with acute diarrhea and 108healthy age-matched control children were examined for enteric bacterial pathogens, protozoa, enteric adenovirus, and rotavirus. An enteropathogen was identified in 75 patients (40%) and in 21 controls (20%). A random sample of specimens without an identifiable pathogen wasthen examined for SRV particles by immune electron microscopy (IBM) using commercial human gamma globulin. Viruses of 26-30 nm diameter that were not enteroviruses were detected in specimens from 9 (12.5%) of the 7l patients and 1 (1.8%) of the 53 control subjects (P < .04). Of6 patients with available acute and convalescent sera, 4 demonstrated a significant immune response when tested by IBM. All patients experienced a mild, self-limited (1–3 days) illness. These findings suggest that SRV may be endemic in the Baltimore community and may result in clinically significant diarrheal illnesses. [ABSTRACT FROM PUBLISHER]