RESUMO
Simple random walk considerations are used to interpret rodent population data collected in Hantavirus-related investigations in Panama regarding the short-tailed cane mouse, Zygodontomys brevicauda. The diffusion constant of mice is evaluated to be of the order of (and larger than) 200 meters squared per day. The investigation also shows that the rodent mean square displacement saturates in time, indicating the existence of a spatial scale which could, in principle, be the home range of the rodents. This home range is concluded to be of the order of 70 meters. Theoretical analysis is provided for interpreting animal movement data in terms of an interplay of the home ranges, the diffusion constant, and the size of the grid used to monitor the movement. The study gives impetus to a substantial modification of existing theory of the spread of the Hantavirus epidemic which has been based on simple diffusive motion of the rodents, and additionally emphasizes the importance for developing more accurate techniques for the measurement of rodent movement.
Assuntos
Arvicolinae/fisiologia , Comportamento Animal , Comportamento de Retorno ao Território Vital , Modelos Biológicos , Animais , Arvicolinae/virologia , Ecologia , Feminino , Infecções por Hantavirus/epidemiologia , Infecções por Hantavirus/transmissão , Infecções por Hantavirus/veterinária , Masculino , Panamá/epidemiologia , Densidade Demográfica , Doenças dos Roedores/epidemiologia , Doenças dos Roedores/transmissão , Doenças dos Roedores/virologiaRESUMO
Antibodies to hantaviruses in two species of sigmodontine rodents (Peromyscus maniculatus and Reithrodontomys sumichrasti) collected in central Mexico are reported. Peromyscus maniculatus, a common species throughout much of Mexico, is the reservoir of Sin Nombre virus (SNV), the etiologic agent of the great majority of cases of hantavirus pulmonary syndrome (HPS) in North America. Although the identity of the virus detected in P. maniculatus in Mexico could not be determined by these serologic results, our findings suggest that SNV may occur throughout the range of P. maniculatus in North America. If true, the failure to identify HPS in Mexico is not due to the absence of pathogenic hantaviruses in Mexico.
Assuntos
Infecções por Hantavirus/veterinária , Muridae/virologia , Orthohantavírus/isolamento & purificação , Peromyscus/virologia , Doenças dos Roedores/epidemiologia , Animais , Anticorpos Antivirais/análise , Feminino , Infecções por Hantavirus/epidemiologia , Masculino , México/epidemiologia , Sorotipagem/veterináriaRESUMO
Between 1993 and 1998, 10 cases of clinical hantavirus infection were diagnosed in Brazil. Hantavirus-specific IgM, or positive immunohistochemical analysis for hantavirus antigen, or positive reverse transcription-polymerase chain reaction results for hantavirus RNA were used to confirm nine of these cases; eight were hantavirus pulmonary syndrome (HPS), and one was mild hantavirus disease. The remaining clinical case of hantavirus infection was fatal, and no tissue was available to confirm the diagnosis. During the first 7 months of 1998, five fatal HPS cases caused by a Sin Nombre-like virus were reported from three different regions in the State of São Paulo, Brazil: two in March (Presidente Prudente Region), two in May (Ribeirão Preto Region), and one in July (Itapecerica da Serra Region). Epidemiologic, ecologic, and serologic surveys were conducted among case contacts, area residents, and captured rodents in five locations within the State of São Paulo in June of 1998. Six (4.8%) of 125 case contacts and six (5.2%) of 116 area residents had IgG antibody to Sin Nombre virus (SNV) antigen. No case contacts had a history of HPS-compatible illness, and only one area resident reported a previous acute respiratory illness. A total of 403 rodents were captured during 9 nights of trapping (1969 trap nights). All 27 rodents that were found to be positive for IgG antibody to SNV antigen were captured in crop border and extensively deforested agricultural areas where four of the 1998 HPS case-patients had recently worked. The IgG antibody prevalence data for rodents suggest that Bolomys lasiurus and perhaps Akodon sp. are potential hantavirus reservoirs in this state of Brazil.
Assuntos
Anticorpos Antivirais/sangue , Reservatórios de Doenças , Síndrome Pulmonar por Hantavirus/epidemiologia , Orthohantavírus/imunologia , Doenças dos Roedores/virologia , Zoonoses , Adolescente , Adulto , Animais , Antígenos Virais/imunologia , Brasil/epidemiologia , Reservatórios de Doenças/veterinária , Evolução Fatal , Feminino , Orthohantavírus/isolamento & purificação , Infecções por Hantavirus/epidemiologia , Infecções por Hantavirus/virologia , Síndrome Pulmonar por Hantavirus/virologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Prevalência , Doenças dos Roedores/imunologia , Roedores , Estudos SoroepidemiológicosRESUMO
We recently described a novel hantavirus (HMV-1) of the western harvest mouse Reithrodontomys megalotis. Screening of 181 additional specimens of Reithrodontomys from the United States and Mexico, including samples of R. mexicanus, R. sumichrasti, and R. gracilis of Costa Rica, for antibodies to hantavirus nucleocapsid protein revealed a widespread enzootic of hantavirus infection. Genetic analyses of 7 S genomes of Reithrodontomys-associated hantaviruses demonstrated that the enzootic of HMV-1 extends from central Mexico into the southwestern United States. A presumed deer mouse hantavirus was found in an R. megalotis animal in Mexico. A highly divergent HMV-1-like virus, tentatively called HMV-2, was identified in a Costa Rican R. mexicanus. These data suggest a longstanding radiation of hantaviruses among New World harvest mice. We identify possible opportunities for genetic exchange among hantaviruses of related rodent hosts.
Assuntos
Variação Genética , Orthohantavírus/genética , Orthohantavírus/isolamento & purificação , Sigmodontinae/virologia , Animais , Sequência de Bases , Peso Corporal , Costa Rica , Primers do DNA/genética , DNA Viral/genética , Feminino , Genótipo , Orthohantavírus/classificação , Masculino , México , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Especificidade da Espécie , Estados UnidosRESUMO
Genome size (the amount of DNA per cell) was measured by flow-cytometric analysis in seven species of a chromosomally variable rodent genus: Ctenomys boliviensis, C. conoveri, C. frater, C. leucodon, C. lewisi, C. opimus, and C. steinbachi. The mean genome size of these species was 7.19 pg DNA and little inter- and intra-specific variation was observed. Genome size was not correlated with diploid number, suggesting that chromosomal evolution at this level is independent of total DNA content. A hypothetical taxonomic unit optimization procedure was carried out using genome size change on a Wagner tree derived from allozyme data. Allozyme evolution and genome size change are linked by a weak, but significant, negative correlation suggestive of preferential genic evolution in the absence of genome size evolution.
Assuntos
Evolução Biológica , Genoma , Roedores/genética , Animais , Bolívia , Cromossomos , DNA/análise , DNA/genética , Variação Genética , Filogenia , Especificidade da EspécieRESUMO
We surveyed 605 households selected by conglomerate random sampling in a typical Chilean city in order to study patterns of utilization of medicinal agents. The critical item investigated drug use in the week preceding the interview. The 95% confidence limits for drug utilization were 24.1 and 26.8% and for medicinal plants 16.7 and 18.7%. Mothers (35.7%) and children (32.1%) used more drugs than adult males. Analgesics and minor tranquilizer were the drugs most frequently used, the main indication being related to respiratory diseases. Self prescription of drugs was about 30%.