Decifrando o "mistério dos gêmeos": vinte anos de pesquisa em Cândido Godói, Rio Grande do Sul / Solving the "twins mystery": twenty years of research in Cândido Godói, Rio Grande do Sul state

Cândido Godói (CG) é um pequeno município brasileiro localizado no noroeste do Rio Grande do Sul e é conhecido como "Cidade dos Gêmeos" devido à alta taxa de nascimentos gemelares na região. Diante de um fato tão notável, muitas explicações foram sugeridas. Entre estas teorias, a que mais recebeu atenção da mídia, mesmo sem base científica, foi a de que a gemelaridade seria fruto de experimentos de um médico nazista alemão foragido após a Segunda Guerra Mundial. A convite da própria comunidade de CG, nosso grupo de pesquisa trabalha para resolver este mistério desde 1994, analisando diferentes fatores possivelmente relacionados, em especial suas características genéticas. Aqui, nós sumarizamos os principais resultados obtidos em mais de duas décadas de pesquisa, com foco nas particularidades do processo de comunicação dos resultados, aspectos éticos e como os achados científicos naquela comunidade contribuem não apenas com a resolução de um mistério histórico e local, mas também com o estudo de outras questões, como a reprodução humana e as bases biológicas da gemelaridade. (AU)

Cândido Godói (CG) is a small town located in the northwest region of Rio Grande do Sul state which is known as "Town of Twins" because of the high rate of twin births. Many explanations have been suggested for such a noteworthy fact. The theory that has received most attention from the press, despite a lack of scientific evidence, was that twinning would result from experiments conducted by a Nazi German physician who had been a fugitive after World War II. Invited by the local community, our research team has been dedicated to solving this mystery since 1994 by analyzing different possibly related factors, especially genetic characteristics. In this paper, we summarize the main results obtained in more than two decades of research, focusing on the particular communication process of the results, ethical aspects, and how the scientific findings in that community have contributed not only to the resolution of a historical and localized mystery, but also with the study of other issues such as human reproduction and biological basis of the twinning process. (AU)

Survey of Bancroftian filariasis infection in humans and Culex mosquitoes in the western Brazilian Amazon region: implications for transmission and control

Introduction The aim of this work was to identify possible lymphatic filariasis foci in the western Brazilian Amazonian that could be established from the reports of Rachou in the 1950s. The study was conducted in three cities of the western Brazilian Amazon region - Porto Velho and Guajará-Mirim (State of Rondônia) and Humaitá (State of Amazonas). Methods For human infection evaluation thick blood smear stained with Giemsa was used to analyze samples collected from 10pm to 1am. Polymerase chain reaction (PCR) was used to examine mosquito vectors for the presence of Wuchereria bancrofti DNA. Humans were randomly sampled from night schools students and from inhabitants in neighborhoods lacking sanitation. Mosquitoes were collected from residences only. Results A total 2,709 night students enrolled in the Program for Education of Young Adults (EJA), and 935 people registered in the residences near the schools were examined, being 641 from Porto Velho, 214 from Guajará-Mirim and 80 from Humaitá. No individual examined was positive for the presence of microfilariae in the blood stream. A total of 7,860 female Culex quinquefasciatus specimens examined were negative by PCR. Conclusions This survey including human and mosquito examinations indicates that the western Amazon region of Brazil is not a focus of Bancroftian filariasis infection or transmission. Therefore, there is no need to be included in the Brazilian lymphatic filariasis control program. .