Banca de DEFESA: LUIZ HENRIQUE MACIEL FEITOZA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : LUIZ HENRIQUE MACIEL FEITOZA
DATA : 13/10/2021
HORA: 14:00
LOCAL: Sala Virtual Remota
TÍTULO:

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PALAVRAS-CHAVES:

Amazon, Anthropophily, Biting Midges, OROV, RT-qPCR

PÁGINAS: 90
GRANDE ÁREA: Ciências Biológicas
ÁREA: Biologia Geral
RESUMO:

The insects of the genus Culicoides are dipterans of the family Ceratopogonidae. Some species have medical and veterinary importance and C. paraensis is considered a vector of the Oropouche Virus (OROV) in the urban cycle of the disease. It is a species highly adapted to urban and periurban environments and has anthropophilic behavior, being found in high density in urban centers of the Brazilian Amazon. The studies of infection and experimental transmission have shown that C. paraensis is capable of infecting and transmitting OROV in areas with arbovirus outbreaks. Due to the great abundance of insects of the genus Culicoides in Porto Velho, mainly of C. paraensis, and with the recent emergence and reemergence of OROV in Brazil, it is necessary to investigate entomological indexes of biting midges and the dynamics of transmission by this vector. The objective of this dissertation was to evaluate the importance of C. paraensis as a potential vector of Oropouche Virus in the urban area of Porto Velho through molecular investigation for natural infection and study of vector behavior by analyzing hematophagic activity and its abundance as a function of meteorological parameters. The captures occurred in two localities in the urban area of Porto Velho by means of outdoor human landing catches (HLC). Samplings occurred during three days from 6:00 am to 8:00 pm, in July, August (dry season) and December 2019 and in January 2020 (rainy season). Generalized Linear Mixed Models were performed to analyze the response of insect hematophagic behavior to seasons, daily hour and meteorological factors (temperature and relative humidity). Total RNA extracted from insects were subject to RT-qPCR, for the detection of viral RNA using the S segment as the OROV target region. Overall, 6,079 individuals were captured which were taxonomically identified as C. paraensis. In the Juscelino Kubitschek neighborhood, 2,725 specimens (44.8%) were captured, while in Nova Esperança there were 3,354 insects (55.2%). During the dry season, 1,488 individuals (24.5%) were sampled, and 4,591 (75.5%) in the rainy season. Considering total number of insects regardless of month and neighborhood, the highest activity peak occurred between 4:00 pm and 6:00 pm. In December, another peak was observed between 11:00 am and 1:00 pm, while in the other months the peak trend was maintained in the range of 4:00 pm to 6:00 pm. The hourly number of biting midges remained more uniform and with fewer oscillations (peaks) during the dry season. All independent variables had significant influence on the biting midges, with rainy season, temperature between 30°C and 32°C and relative humidity between 75% and 85% as predictor parameters for higher average insect capture. The results confirm that this biting midge specie have diurnal activity and are attracted to humans for blood feeding: a single collector captured 220 individuals from 5:00 pm to 6:00 pm. The activity peak variation between study areas suggests that physical and meteorological factors of microenvironments may be influencing the species behavior. None RNA samples had amplification for target OROV sequences, which can be explained by the possible noncirculation of OROV in the human population in the urban area of Porto Velho, C. paraensis as a secondary or non-vector vector, and low infection rate among insects. These hypotheses, together with the probable underreporting of human cases of OROV in the Amazon region, reinforce the need for studies on the species bionomy and molecular investigation to explain the role of Culicoides paraensis as a vector of this arbovirus.

MEMBROS DA BANCA:
Externo à Instituição - FRANCINALDO SOARES SILVA - UFMA
Presidente - 902.446.996-15 - GENIMAR REBOUÇAS JULIÃO - UNIR
Interno - 838.495.134-91 - JANSEN FERNANDES MEDEIROS - UNIR