Browsing by Autor "Nurtop, Elif"

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High SARS-CoV-2 Prevalence among Healthcare Workers in Cochabamba, Bolivia.
(2022) Saba Villarroel, Paola Mariela; Castro Soto, María Del Rosario; Undurraga, Verónica; Sanz, Heydi; Jaldín, Ana María; Ninove, Laetitia; Nurtop, Elif; Pezzi, Laura; Mohamed Ali, Souand; Amroun, Abdennour; Seston, Morgan; de Lamballerie, Xavier
Healthcare workers (HCWs) are at increased risk of SARS-CoV-2 infection. The aim of the study was to estimate the SARS-CoV-2 seroprevalence among HCWs in Cochabamba, Bolivia and to determine the potential risk factors. In January 2021, a cross-sectional SARS-CoV-2 seroprevalence study was conducted in 783 volunteer clinical and non-clinical HCWs in tertiary care facilities. It was based on IgG detection using ELISA, chemiluminiscence, and seroneutralisation tests from dried blood spots. Analysis revealed a high seroprevalence (43.4%) of SARS-CoV-2 IgG antibodies. The combination of anosmia and ageusia (OR: 68.11; 95%-CI 24.83-186.80) was predictive of seropositivity. Belonging to the cleaning staff (OR: 1.94; 95%-CI 1.09-3.45), having more than two children in the same house (OR: 1.74; 95%-CI 1.12-2.71), and having been in contact with a close relative with COVID-19 (OR: 3.53; 95%-CI 2.24-5.58) were identified as risk factors for seropositivity in a multivariate analysis. A total of 47.5% of participants had received medication for COVID-19 treatment or prevention, and only ~50% of symptomatic subjects accessed PCR or antigenic testing. This study confirms a massive SARS-CoV-2 attack rate among HCWs in Cochabamba by the end of January 2021. The main risk factors identified are having a low-skilled job, living with children, and having been in contact with an infected relative in the household.
Improving SARS-CoV-2 variants monitoring in the absence of genomic surveillance capabilities: a serological study in Bolivian blood donors in October 2021 and June 2022.
(2025) Inchauste, Lucia; Nurtop, Elif; Bautista Machicado, Lissete; Leigue Roth, Yanine; Lenz Gonzales, Shirley; Herrera, Maria Luisa; Mina Villafan, Katty; Mamani Mamani, Pedro; Ramos Espinoza, Marcelo; Pavel Suarez, Juan Carlos; Garcia Copa, Juan Cansio; Leigue Zabala, Yitzhak; Arancibia Cardozo, Etzel; Gallian, Pierre; de Lamballerie, Xavier; Priet, Stéphane
BACKGROUND: Unlike genomic data, serological data have not been previously leveraged to evaluate the SARS-CoV-2 variants circulation. In Bolivia, sustained genomic surveillance capacities were lacking, especially at the beginning of the pandemic. METHODS: In 2021 and 2022 we estimated the prevalence of anti-SARS-CoV-2 antibodies in Bolivian blood donors and explored the feasibility of using virus serum neutralization data for variants thought to have circulated to map their circulation across all departments over a year-long follow-up period. Anti-S1 and anti-NCP SARS-CoV-2 IgGs were studied, along with virus neutralization tests for ancestral-D614G, Gamma, Delta, and Omicron BA.1 lineages of SARS-CoV-2. RESULTS: Between 2021 and 2022, the overall prevalence of anti-S1 and anti-NCP antibodies increased, reaching values over 90%, demonstrating that a large proportion of the Bolivian population was no longer naïve to the virus. Viral neutralization data, analyzed through multiple approaches, revealed the spread of the Gamma variant up to 2021, particularly impacting northern departments. In 2022, Gamma continued to circulate in southernmost departments of the country, and the emergence of Omicron BA.1 was detected. These trends align with publicly available genomic data from neighboring countries. CONCLUSIONS: Our serological analyses successfully identified both new antigenic groups, such as Omicron BA.1, and individual variants related to previously circulating groups, such as Delta. The study contributes insights into overall population immunity to SARS-CoV-2 and variant-specific immunity levels across different regions of Bolivia. It also emphasizes the potency of seroprevalence studies in informing public health decisions and underscores their value in capturing the initial phases of emerging epidemics when variant diversity is limited, facilitating timely genomic surveillance setup. FUNDING: This study was supported by the French National Research Institute for Sustainable Development (IRD), the project EMERGEN-PRI #22275 of the ANRS I MIE (INSERM), and the European Union's Horizon 2020 research and innovation program (European Virus Archive Global, grant agreement No. 871029). The funders of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report.