ABSTRACT
This study was undertaken to investigate the prevalence of Mansonella ozzardi infection and to estimate the parasitic infection rate (PIR) in simuliid black flies in the municipality of Pauini, Amazonas, Brazil. We used thick blood films to examine 921 individuals in 35 riverine communities along the Pauini and Purus Rivers. Simuliids were caught in several communities. Flies were identified, stained with haematoxylin and dissected. Overall, 44 (24.86 percent) of 177 riverines were infected in communities on the Pauini River and 183 (24.19 percent) of 744 on the Purus. The prevalence was higher in men (31.81 percent and 29.82 percent) than in women (17.98 percent and 19.18 percent) and occurred in most age groups. The prevalence increased sharply in the 28-37 (50 percent and 42.68 percent) age group and increased in the older age classes. The highest prevalence was in farmers (44 percent and 52.17 percent, respectively) in the Pauini and Purus Rivers. Only Cerqueirellum amazonicum (Simuliidae) transmits M. ozzardi in this municipality, and we found a PIR of 0-8.43 percent and infectivity rate of 0-3.61 percent. These results confirm that rates of M. ozzardi infection are high in Pauini and suggest that its prevalence may be far greater than has been previously reported due to the absence of a program for treating the population.
Subject(s)
Adolescent , Adult , Aged , Animals , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Young Adult , Insect Vectors/parasitology , Mansonella/isolation & purification , Mansonelliasis/epidemiology , Simuliidae/parasitology , Brazil/epidemiology , Insect Vectors/classification , Mansonelliasis/diagnosis , Prevalence , Simuliidae/classification , Young AdultABSTRACT
Este estudo teve por objetivo verificar padrões morfológicos que proporcionassem o correto diagnóstico de Simulium (Chirostilbia) pertinax Kollar. A análise morfológica de fêmeas e pupas permitiu encontrar estruturas bem características e de fácil utilização para identificação da espécie. Alguns caracteres diagnósticos (coloração do escudo, área nudiocular e paraprocto) podem apresentar pequenas variações e outros são constantes (coloração das pernas, cibário, forquilha, filamentos branquiais e casulo).
This study had as objective to verify the morphologic patterns that provide a correct diagnosis of Simulium (Chirostilbia) pertinax Kollar. The analysis of female and pupa morphology allowed to find characteristic structures that could be easily used to identify the species.Some diagnostic characteres (shield coloration, nudiocular area and paraprocto) show small variations and other are constant (leg coloration, cibarium, fork, branchial filaments and cocoon).