Investigação da ocorrência da Mansonella ozzardi no Estado de Rondônia, Amazônia Ocidental

Abstract

Introduction: Mansonella ozzardi, a human filarial nematode transmitted by Diptera Simuliidae flies (black flies), is widely spread in the Amazon, while the occurrence of mansonelliasis in the State of Rondônia (Western Amazonia) has not been reported thus far. The existence of this parasitic disease in this state is investigated in this study. Methods: A total of 4,452 people who lived alongside the Madeira, Mamore, Guapore, Machado and Preto Rivers, in the State of Rondônia, were examined using the thick blood smear method. Alongside the Machado and Guapore rivers, 2,112 adult simuliid specimens were captured. Results: Infected people were not reported, although simuliids with vector potential such as Cerqueirellum pydanielli, C. argentiscutum and C. amazonicum were found. Conclusions: This study registered no infected people. This finding may be explained by the individuals' low level of microfilaremia that is below the limit of detection of the diagnostic method used in the study or insufficient migration of people infected with M. ozzardi from endemic areas, making it impossible to introduce the disease into Rondônia. Further studies using more sensitive diagnostic techniques could shed light on this question.Keywords: Mansonella ozzardi. Microfilariae. Simuliidae. State of Rondônia. RESUMOIntrodução: Mansonella ozzardi é uma filária humana que tem como vetor dípteros simulídeos e é amplamente distribuída na Amazônia. Não há informações sobre a ocorrência de casos de mansonelose no Estado de Rondônia, e neste trabalho procurou-se investigar a situação epidemiológica desta parasitose em áreas urbanas e ribeirinhas na Amazônia Ocidental. Métodos: Foram examinados 4.452 moradores às margens dos rios Madeira, Mamoré, Guaporé, Machado e Preto em Rondônia, através da técnica da gota espessa de sangue. Capturou-se às margens do rio Machado e Guaporé 2.112 simulídeos adultos das espécies Cerqueirellum pydanieli e Chirostilbia pertinax. Resultados: Não foram encontradas pessoas infectadas com M. ozzardi e foram encontradas diferentes espécies de simulídeos com potencial de transmissão da mansonelose. Conclusões: Não foram encontrados indivíduos infectados com M. ozzardi neste estudo. Este fato pode ser explicado pela existência de pacientes com baixas microfilaremias, associado à técnica diagnóstica de baixa sensibilidade utilizada no estudo. Pode-se ainda aventar a possibilidade de ter ocorrido migração insuficiente de pacientes infectados de áreas endêmicas, impossibilitando a implantação da endemia. Estudos posteriores com técnicas diagnósticas mais sensíveis podem ajudar a esclarecer esta questão. Palavras-chaves:Mansonella ozzardi. Microfilárias. Simuliidae. Rondônia.

Mansonelliasis, a neglected parasitic disease in Haiti

“…The high prevalence rates observed in Haiti are close to those reported in the Amazonian area ( Lightner et al 1980 , Kozek et al 1982 , 1983 , 1984 , 1983 , 1984 , Formica & Botto 1990 , Bartoloni et al 1999 , Gómez & Guerrero 2000 , Medeiros et al 2008 , 2009 , 2011 , 2014 , , 2009 , 2011 , 2014 , Martins et al. 2010 , Basano et al 2011 , Adami et al 2014) and in the northeast of Argentina ( Taranto & Castelli 1988) . The non-specific symptoms reported in most cases could not be easily related to M. ozzardi .…”

Mansonellosis: current perspectives

“… 3 , 4 , 15 , 29 , 79 – 90 Because of these vectorial differences, it was once thought that M. ozzardi from the Caribbean islands and those from continental South America might be different species ( Table 1 ). 85 , 91 Artificial-infection experiments and the recent publication of DNA sequences, however, strongly indicate that parasites from the two regions are morphologically, biologically, and genetically near identical, and thus that they are most parsimoniously regarded as just one species. 2 , 17 , 28 , 48 , 50 , 58 …”

New records of Mansonella ozzardi: a parasite that is spreading from the state of Amazonas to previously uninfected areas of the state of Acre in the Purus River region

“…Subsequent studies have provided data on the distribution and prevalence of human infection by this filarial species in northern Brazil. Additionally, isolated studies have been conducted along the Purus and Negro Rivers and in other areas of western Amazon (Shelley 1975, Medeiros et al 2007, 2008, 2009, 2011, Martins et al 2010, Basano et al 2011). In these areas, transmission of the parasite is related to the presence of haematophagous blackfly vectors that share the same geographical distribution, including Simulium amazonicum Goeldi and Simulium argentiscutum (Shelley et al 1980).…”