Geographical distribution of rodent-associated hantaviruses in Texas.

The purpose of this study was to increase our knowledge of the geographic distribution and natural host range of hantaviruses in Texas, southeastern New Mexico, and Mexico. Blood samples from 3,225 wild rodents, representing 34 species, were tested for hantavirus antibody (IgG), using an enzyme-linked immunosorbent assay. Hantavirus antibody was found in one or more rodents from each of 13 counties in Texas, Otero County in southeastern New Mexico, and Mexico State (central Mexico). The 133 antibody-positive rodents included seven Peromyscus species (P. attwateri, P. boylii, P. hylocetes, P. leucopus, P. maniculatis, P. melanotis, and P. pectoralis), Sigmodon hispidus, Oryzomys palustris, two Reithrodontomys species (R. fulvescens and R. megalotis), Neotoma albigula, and Perognathus merriami. This study provides further evidence that rodent-associated hantaviruses are geographically widely distributed in Texas. The discovery of antibody in P. hylocetes and P. melanotis is evidence that peromyscine rodents in Mexico are naturally associated with viruses belonging to the genus Hantavirus.

Allpahuayo virus: a newly recognized arenavirus (arenaviridae) from arboreal rice rats (oecomys bicolor and oecomys paricola) in northeastern peru.

Allpahuayo virus was initially isolated from arboreal rice rats (Oecomys bicolor and Oecomys paricola) collected during 1997 at the Allpahuayo Biological Station in northeastern Peru. Serological and genetic studies identified the virus as a new member of the Tacaribe complex of the genus Arenavirus. The small (S) segment of the Allpahuayo virus prototype strain CLHP-2098 (Accession No. AY012686) was sequenced, as well as that of sympatric isolate CLHP-2472 (Accession No. AY012687), from the same rodent species. The S segment was 3382 bases in length and phylogenetic analysis indicated that Allpahuayo is a sister virus to Pichinde in clade A. Two ambisense, nonoverlapping reading frames were identified, which result in two predicted gene products, a glycoprotein precursor (GPC) and a nucleocapsid protein (NP). A predicted stable single hairpin secondary structure was identified in the intergenic region between GPC and NP. Details of the genetic organization of Allpahuayo virus are discussed.

Detection of pathogenic Leptospira spp. infections among mammals captured in the Peruvian Amazon basin region.

To identify potential zoonotic reservoirs of pathogenic leptospires in the Peruvian Amazon basin, wild mammals were trapped from July 1997 to December 1998 near the city of Iquitos. After extraction of nucleic acids from animal kidneys, DNA of pathogenic leptospires was identified by polymerase chain reaction (PCR) assays using one of two primer sets, one amplifying a region of the 23S rRNA gene, and the other amplifying a gene fragment specific for Leptospira spp (G1/G2 primers). Overall, 29% (40 of 136) of the mammals tested showed evidence of renal infection by Leptospira spp., including 20% (13 of 64) of the rodents, 39% (20 of 51) of the marsupials, and 35% (7 of 20) of the chiropterans (bats). Marsupials and chiropterans were implicated as more significant reservoir hosts of leptospires pathogenic to humans than previously recognized.

Mayaro virus disease: an emerging mosquito-borne zoonosis in tropical South America.

This report describes the clinical, laboratory, and epidemiological findings on 27 cases of Mayaro virus (MV) disease, an emerging mosquito-borne viral illness that is endemic in rural areas of tropical South America. MV disease is a nonfatal, dengue-like illness characterized by fever, chills, headache, eye pain, generalized myalgia, arthralgia, diarrhea, vomiting, and rash of 3-5 days' duration. Severe joint pain is a prominent feature of this illness; the arthralgia sometimes persists for months and can be quite incapacitating. Cases of two visitors from the United States, who developed MV disease during visits to eastern Peru, are reported. MV disease and dengue are difficult to differentiate clinically.