Banca de DEFESA: DANIELLE VIVIANE FERNANDES BEZERRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : DANIELLE VIVIANE FERNANDES BEZERRA
DATE: 18/07/2025
TIME: 09:00
LOCAL: https://meet.google.com/wuq-xihi-rfh
TITLE:

Complexity of neglected tropical diseases in Brazil: HIV/Leishmania infantum coinfection and risk exposure to schistosomiasis

KEY WORDS:

Asymptomatic Infections; Immunosenescence; Immune Exhaustion; Water Use.

PAGES: 143
BIG AREA: Ciências da Saúde
AREA: Medicina
SUMMARY:

Visceral leishmaniasis and schistosomiasis are neglected tropical diseases that have a significant impact on populations living in social and environmental vulnerability. In this thesis, two distinct population-based studies were conducted: (1) an assessment of the clinical progression of people living with HIV residing in Natal and at risk of exposure to Leishmania infantum, and (2) an evaluation of factors associated with Schistosoma mansoni infection in individuals at risk of exposure to the pathogen, residing in the municipality of Pureza, Rio Grande do Norte. The first study hypothesized that adherence to antiretroviral therapy reduces the risk of developing AIDS/visceral leishmaniasis, while the second study assumed that risk behaviors for exposure to Schistosoma mansoni persist despite the well-documented exposure areas in that municipality. The first study was observational, with data collected at two time points (T1 and T2), and included 829 people living with HIV at risk of exposure to Leishmania infantum. Participants were grouped based on HIV/Leishmania coinfection, determined by serological and/or molecular tests, into two groups: asymptomatic HIV/Leishmania coinfection and HIV only. Immune cell activation, senescence, and exhaustion markers were assessed at T2 by flow cytometry. The prevalence of asymptomatic HIV/Leishmania coinfection at T1 was 11.5%. No participants developed VL between the 8,2 ± 2,9 months of follow-up. Regular use of antiretroviral therapy was observed in 89.2% of participants at T1 and 98.2% at T2. A significant improvement in CD4+ cell counts was observed over time, along with an increase in the proportion of individuals with undetectable viral loads, in both coinfected and HIV only groups (p ≤ 0.0011 and p = 0.004, respectively), likely due to ART adherence. Levels of activated, senescent, and exhausted T cells did not differ between groups, suggesting that consistent antiretroviral therapy adherence appears to prevent immune decline, thereby halting progression to leishmaniasis. The second study had a cross-sectional design and evaluated 315 residents of the municipality of Pureza using the Kato-Katz parasitological technique for the detection of Schistosoma mansoni. Participants were divided into four groups: (1) Newly S. mansoni cases (n = 44); (2) Past history of S. mansoni treatment (n = 78); (3) Neighbor untreated contacts (n = 158); and (4) control (n = 35). Male sex was more prevalent among Newly S. mansoni cases (p < 0.05). Of this group, 38.6% of individuals had previously been treated for S. mansoni, indicating reinfection. The average monthly per capita income was 372.0 ± 225.9 BRL, and 45.1% of participants receiving Bolsa Família, a social program of income transfer. Most participants in the control group reported never freshwater body collection (77.1%). Among those who reported using them in this group, the main purpose was recreational bathing – a behavior known to carry a higher risk of exposure to the pathogen. Despite awareness of risk areas, the use of water collections for recreational activities and the occurrence of reinfection indicate the persistence of exposure behaviors associated with S. mansoni infection.

COMMITTEE MEMBERS:
Presidente - 350647 - SELMA MARIA BEZERRA JERONIMO
Externa ao Programa - 1714243 - DANIELLA REGINA ARANTES MARTINS SALHA - UFRNExterna ao Programa - ***.077.257-** - JOANNA GARDEL VALVERDE GALVÃO - NÃO INFORMADO
Externo à Instituição - ANASTACIO DE QUEIROZ SOUSA
Externo à Instituição - EDGAR MARCELINO DE CARVALHO FILHO - UFBA