RESUMO
BACKGROUND: Plasmodium vivax circumsporozoite variants have been identified in several geographical areas. The real implication of the genetic variation in this region of the P. vivax genome has been questioned for a long time. Although previous studies have observed significant association between VK210 and the Duffy blood group, we present here that evidences of this variation are limited to the CSP central portion. METHODS: The phylogenetic analyses were accomplished starting from the amplification of conserved domains of 18 SSU RNAr and Cyt B. The antibodies responses against the CSP peptides, MSP-1, AMA-1 and DBP were detected by ELISA, in plasma samples of individuals infected with two P. vivax CS genotypes: VK210 and P. vivax-like. RESULTS: These analyses of the two markers demonstrate high similarity among the P. vivax CS genotypes and surprisingly showed diversity equal to zero between VK210 and P. vivax-like, positioning these CS genotypes in the same clade. A high frequency IgG antibody against the N- and C-terminal regions of the P. vivax CSP was found as compared to the immune response to the R- and V- repetitive regions (p = 0.0005, Fisher's Exact test). This difference was more pronounced when the P. vivax-like variant was present in the infection (p = 0.003, Fisher's Exact test). A high frequency of antibody response against MSP-1 and AMA-1 peptides was observed for all P. vivax CS genotypes in comparison to the same frequency for DBP. CONCLUSIONS: This results target that the differences among the P. vivax CS variants are restrict to the central repeated region of the protein, mostly nucleotide variation with important serological consequences.
Assuntos
Variação Genética , Proteína 1 de Superfície de Merozoito/genética , Plasmodium vivax/genética , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Citocromos b/genética , Genótipo , Humanos , Malária Vivax/parasitologia , Proteínas de Membrana/genética , Proteínas de Membrana/imunologia , Proteína 1 de Superfície de Merozoito/imunologia , Dados de Sequência Molecular , Filogenia , Plasmodium vivax/classificação , Reação em Cadeia da Polimerase , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/imunologia , Sequências Repetitivas de Ácido Nucleico , Análise de Sequência de DNARESUMO
A retrospective study to describe the epidemiology of human leptospirosis in Trinidad and Tobago during 19962007 was conducted. All confirmed cases of leptospirosis was analyzed according to age, sex, seasonality and geographic distribution. A total of 278 cases were recorded, with an average annual incidence rate of 1.84 per 100,000 population. Seventy-five percent of the cases occurred during the wet season, with the highest number of cases recorded in November. A positive correlation was found between number of cases and rainfall. Males constituted 80% of all cases, and the overall male:female ratio was 4.6:1. The total case fatality rate was 5.8 per cent, with deaths among males four times more common than in females. Clinical leptospirosis was greatest in the 1019 age group and lowest in the 09 age group. The total prevalence was 22 per 100,000 population, with the highest prevalence 41 per 100,000 recorded in the regional corporation of Sangre Grande and the lowest (6 per 100,000) in the city of Port of Spain. The lack of important information and active surveillance showed that the level of awareness of the disease is low in the country. The disease is still under-reported, and is considered to be of significant public health importance.
Assuntos
Humanos , Leptospirose , Epidemiologia , Distribuição por Idade e Sexo , Fatores de Risco , Trinidad e TobagoRESUMO
A retrospective study to describe the epidemiology of human leptospirosis in Trinidad and Tobago during 1996-2007 was conducted. All confirmed cases of leptospirosis was analyzed according to age, sex, seasonality and geographic distribution. A total of 278 cases were recorded, with an average annual incidence rate of 1.84 per 100,000 population. Seventy-five percent of the cases occurred during the wet season, with the highest number of cases recorded in November. A positive correlation was found between number of cases and rainfall. Males constituted 80% of all cases, and the overall male:female ratio was 4.6:1. The total case fatality rate was 5.8%, with deaths among males four times more common than in females. Clinical leptospirosis was greatest in the 10-19 age group and lowest in the 0-9 age group. The total prevalence was 22 per 100,000 population, with the highest prevalence 41 per 100,000 recorded in the regional corporation of Sangre Grande and the lowest (6 per 100,000) in the city of Port of Spain. The lack of important information and active surveillance showed that the level of awareness of the disease is low in the country. The disease is still under-reported, and is considered to be of significant public health importance.