Os estimadores para parÃmetros populacionais em amostras coletadas pelo mÃtodo de amostragem Respondent Driven Sampling (RDS) sÃo sensÃveis à presenÃa de observaÃÃes ignoradas e tendem a subestimar os parÃmetros populacionais. A ausÃncia de um quadro de amostragem bem definido para a coleta de amostras em populaÃÃes consideradas escondidas e/ou de acesso difÃcil fez com que o RDS se tornasse uma importante ferramenta de vigilÃncia comportamental e biolÃgica nessas populaÃÃes com maior risco para o HIV, em especial no Brasil. Considerado um mÃtodo de amostragem em cadeia de referÃncia, o RDS utiliza informaÃÃes sobre as conexÃes das redes sociais para obter estimadores contingentes assintoticamente imparciais das caracterÃsticas populacionais e a precisÃo desses estimadores. Estudo multicÃntrico de corte transversal para vigilÃncia epidemiolÃgica e comportamental em populaÃÃes de HSH com 18 anos ou mais foi realizado em dez cidades brasileiras (Manaus, Recife, Salvador, Campo Grande, BrasÃlia, Curitiba, ItajaÃ, Santos, Belo Horizonte e Rio de Janeiro) no ano de 2009 e, coleta, em cada municÃpio, uma amostra pelo RDS. Neste estudo, foi oferecido o teste rÃpido para diagnÃstico da infecÃÃo por HIV Ãqueles que aceitam participar de um prÃ-aconselhamento. Todos os participantes foram inquiridos sobre a realizaÃÃo de testes anti-HIV anteriores ao da pesquisa e sobre qual o diagnÃstico obtido. Com a simulaÃÃo de uma variÃvel dicotÃmica (exemplo: sorologia para HIV positiva ou negativa) sem observaÃÃes ignoradas na rede de recrutamento do Rio de Janeiro e posteriores exclusÃes de 18 recrutados, encontra-se que, a amostra com ignorados à avaliada com base em um nÃmero de observaÃÃes significativamente menor que o da amostra original e o parÃmetro em questÃo (prevalÃncia do HIV) à subestimado. Ainda, com a imputaÃÃo Ãnica das sorologias ignoradas, no contexto descritivo, observam-se, nas amostras com imputaÃÃo, marcadores biolÃgicos que indicam valores mais acurados. No estudo multicÃntrico, para o grupo de participantes que autorrelatou sorologia positiva ou negativa para o HIV e realizou teste rÃpido na pesquisa, observa-se para os autorrelatos elevada concordÃncia (0,88) e sensibilidade de 100% com o padrÃo-ouro teste rÃpido para diagnÃstico do HIV. Finalmente, estimando a prevalÃncia para o HIV nas amostras observadas por municÃpio e geral, e, com a proposta da imputaÃÃo pelo autorrelato do HIV positivo e posterior atribuiÃÃo de sorologia HIV +/- mediante trÃs propostas de imputaÃÃes: todos sÃo negativos, proximidade dos participantes na rede de recrutamento e pela regressÃo logÃstica. Encontra-se nas amostras coletadas a estimativa geral da prevalÃncia do HIV igual a 11,1% sendo, por municÃpio, a menor prevalÃncia em Santos (2,6%) e a maior no Rio de Janeiro (17,6%). Com as imputaÃÃes as prevalÃncias tendem a aumentar e as maiores estimativas sÃo encontradas com a imputaÃÃo por meio da regressÃo logÃstica em sete de nove municÃpios avaliados por essa metodologia. A estimativa geral do HIV pela regressÃo logÃstica à 14,2% sendo, por municÃpio, a menor prevalÃncia no Recife (5,2%) e a maior em BrasÃlia (23,7%). A imputaÃÃo da sorologia de infecÃÃo por HIV pela regressÃo logÃstica ocorre por municÃpio e por intermÃdio de um modelo com acurÃcia mÃnima igual a 70%. / The estimators for population parameters in samples collected by sampling Respondent Driven Sampling (RDS) are sensitive to the presence of observations ignored and tends to underestimate the population parameters. The absence of a clearly defined sampling frame for the collection of samples from populations considered hidden and/or difficult access made the RDS became an important tool for biological and behavioral surveillance in these populations at higher risk for HIV, especially Brazil. Considered a method of sampling in the reference chain, RDS uses information about the connections of social networks for specific asymptotically unbiased estimators of population characteristics and accuracy of these estimators. Multicenter cross-sectional epidemiological and behavioral surveillance for MSM populations in 18 years or more was conducted in 10 cities (Manaus, Recife, Salvador, Campo Grande, Brasilia, Curitiba, ItajaÃ, Santos, Belo Horizonte and Rio de Janeiro) in 2009 and collected in each municipality, a sample through RDS. This study offered the rapid test for diagnosis of HIV infection to those who agreed to participate in a pre-counseling. All participants were asked about testing for HIV prior to the research and about which the diagnosis obtained. By simulating a dichotomous variable (eg, HIV serology positive or negative) without comment ignored in recruiting network in Rio de Janeiro and later recruited 18 deletions, that is, the unknown sample is evaluated from a number of observations significantly smaller than the original sample and the parameter in question (HIV prevalence) is underestimated. Still, with the allocation of single serology ignored in the descriptive context, it is observed in samples with attribution, biological markers indicating that more accurate values. Multicentre study for the group of participants who self-reported positive or negative serology for HIV rapid test and performed the research notes to self-reports, high correlation (0.88) and 100% sensitivity with gold standard rapid test for HIV diagnosis. Finally, estimating the prevalence of HIV in the samples observed by county and general, and the proposed allocation of the self-reported HIV positive and HIV serology subsequent assignment of + / - through three proposed charges: are all negative, proximity of the participants in the network recruitment and by logistic regression. It is found in samples collected from the estimated overall HIV prevalence was equal to 11.1%, by municipality, the lower prevalence in Santos (2.6%) and highest in Rio de Janeiro (17.6%).With the charges tend to increase the prevalence and the highest estimates are found with the imputation logistic regression in 7 of 9 municipalities assessed by this methodology. The estimated overall HIV logistic regression is 14.2% and, by municipality, the lower prevalence in Recife (5.2%) and highest in Brasilia (23.7%). The allocation of serology for HIV by the Logistic Regression occurs by municipality and by a model with a minimum accuracy of 70%.

Parmi les phlébovirus (famille des Bunyaviridae, genre Phlebovirus), ceux qui sont transmis par les phlébotomes de l'Ancien Monde sont largement distribués dans le bassin méditerranéen. Les infections humaines causées certains de ces phlébovirus sont connues depuis longtemps, mais elles restent tout de même négligées en médecine en raison de l'absence de données épidémiologiques solides (problème des réactions croisées) et d'outils de diagnostic rapides et fiables.La première partie de cette thèse a été consacrée à l'optimisation d'un test de neutralisation du virus pour étudier la séroprévalence de 5 virus, et leur capacité respective à infecter les humains et les animaux.La deuxième partie visait à mesurer la séroprévalence de phlébovirus appartenant aux 3 complexes antigéniques transmis par les phlébotomes dans le bassin méditerranéen (Sandfly fever Naples, Sandfly fever Sicilian et Salehabad). Ces études ont été menées sur des sérums de chiens et de chats en Tunisie, Portugal, Grèce/Chypre.La troisième partie a montré la capacité de virus récemment découverts dans le serocomplexe Salehabad (Adana et Medjerda valley virus) à infecter l'homme et les animaux traduisant un potentiel pathogène à explorer par des études spécifiques.La dernière partie a démontré la présence du virus Toscana en Kabylie (Algérie du Nord), et l'exposition extrêmement élevée des populations humaines vivant dans la région, avec des prévalence 10 fois plus élevées que dans les régions les plus à risque du sud-est de la France. / Sandfly-borne phleboviruses, transmitted by phlebotomine sandflies and belonging to the genus Phlebovirus within the Bunyaviridae family are widely distributed in Mediterranean basin. Human diseases caused by infection with phleboviruses are known for a long time, but they are still neglected due to the lack of epidemiological knowledge and of diagnostic tools.The first part of this thesis was dedicated to optimize a comparative virus neutralisation test to study the seroprevalence of selected phleboviruses and to assess the capacity of each virus to infect humans and animals. The second part aimed to estimate the epidemiology of phlebovirus serocomplexes (Naples, Sicilian and Salehabad) in Mediterranean basin. In order to update the presence of these viruses and their capacity to infect animals, several serologic studies were carried out on animal blood samples in Tunisia, Portugal, Greece and Cyprus. The results demonstrated that the phleboviruses belonging to 3 distinct groups are widely circulating and capable to infect non human vertebrate at different rates in studied countries.The third part showed the capacity of newly discovered viruses (Adana and Medjerda valley viruses) belonging to Salehabad serocomplex to infect human and animal at low and high rates, respectively. These findings suggest the medical and veterinary importance of these viruses. The last part of this thesis, confirm the circulation of Toscana virus by seroprevelance study which was carried out in local population in north Algeria where Toscana virus was isolated recently. The high rate of circulate suggests that Toscana virus is heavily affecting sandfly-exposed people in Algeria.

Made available in DSpace on 2016-01-26T18:55:44Z (GMT). No. of bitstreams: 1 DISSERTACAO_COMPLETA_21_07.pdf: 687153 bytes, checksum: b7082f2641dd20fb43158fc2d7bd619e (MD5) Previous issue date: 2008-06-04 / The American Visceral Leishmaniasis (LVA) has been spreading in a short period of time with deep concern for all West of São Paulo State, instead of the measures that have been taken to control it. This search was made in order to study the variability involved in the disease cycle, as well as the efficacy of the measures to control it. The study involved the microregion of Dracena, composed by twelve municipal districts, that belong to Alta Paulista region, extreme West of São Paulo State. The data analyzed were given by the Superintendency of Endemies Control and Adolfo Lutz Institute, Regional Laboratory of Presidente Prudente. From August 2005 to January 2008, were analyzed: the date of phlebotomines detection at the municipal district and the period of the dog and human diagnostic; the death rate of human; the prevalence of suspected dogs tested by serology; the percentage of euthanasia in suspected dogs; correlation between positive dogs and human cases of the disease; comparation of the prevalences among the twelve municipal districts of the studied region. It was constated that, despite the strategies for controlling the LVA in the Alta Paulista region, SP, the disease carries on expansion with deep concern. Some procedures of the Vigilancy Program and LVA Control should be reviewed as for it efficacy and others, fiscalized, in order to increase the credibility and efficacy of the program. / A Leishmaniose Visceral Americana (LVA) vem se alastrando em curto período de tempo, e de forma preocupante por todo Oeste do Estado de São Paulo, apesar das medidas adotadas para seu controle. Essa pesquisa foi realizada com o objetivo de se estudar as variáveis que envolvem o ciclo da enfermidade, assim como a efetividade das medidas de controle. O estudo compreendeu a micro-região de Dracena, composta por doze municípios, pertencentes à Alta Paulista, Extremo - Oeste do Estado de São Paulo. Os dados analisados foram fornecidos pela Superintendência de Controle de Endemias e Instituto Adolfo Lutz, Laboratório Regional de Presidente Prudente. Foram analisadas, no período compreendido entre agosto de 2005 a janeiro de 2008: as datas de detecção do flebotomíneo nos municípios e o período em que houve o diagnóstico em cães e humanos; o número de casos de óbitos humanos; prevalência de cães suspeitos testados por sorologia; porcentagem de eutanásia em cães suspeitos; se houve correlação entre cães positivos e casos da doença em humanos; comparação das prevalências entre os doze municípios da região estudada. Constatou-se que, apesar das estratégias de controle da LVA adotadas na micro-região de Dracena/SP, a doença continua se expandindo de forma preocupante. Alguns procedimentos do Programa de Vigilância e Controle da LVA devem ser revistos quanto a sua efetividade e outros fiscalizados, para que haja maior credibilidade e eficácia do programa.

Made available in DSpace on 2016-07-18T17:53:17Z (GMT). No. of bitstreams: 1 DISSERTACAO_COMPLETA_21_07.pdf: 687153 bytes, checksum: b7082f2641dd20fb43158fc2d7bd619e (MD5) Previous issue date: 2008-06-04 / The American Visceral Leishmaniasis (LVA) has been spreading in a short period of time with deep concern for all West of São Paulo State, instead of the measures that have been taken to control it. This search was made in order to study the variability involved in the disease cycle, as well as the efficacy of the measures to control it. The study involved the microregion of Dracena, composed by twelve municipal districts, that belong to Alta Paulista region, extreme West of São Paulo State. The data analyzed were given by the Superintendency of Endemies Control and Adolfo Lutz Institute, Regional Laboratory of Presidente Prudente. From August 2005 to January 2008, were analyzed: the date of phlebotomines detection at the municipal district and the period of the dog and human diagnostic; the death rate of human; the prevalence of suspected dogs tested by serology; the percentage of euthanasia in suspected dogs; correlation between positive dogs and human cases of the disease; comparation of the prevalences among the twelve municipal districts of the studied region. It was constated that, despite the strategies for controlling the LVA in the Alta Paulista region, SP, the disease carries on expansion with deep concern. Some procedures of the Vigilancy Program and LVA Control should be reviewed as for it efficacy and others, fiscalized, in order to increase the credibility and efficacy of the program. / A Leishmaniose Visceral Americana (LVA) vem se alastrando em curto período de tempo, e de forma preocupante por todo Oeste do Estado de São Paulo, apesar das medidas adotadas para seu controle. Essa pesquisa foi realizada com o objetivo de se estudar as variáveis que envolvem o ciclo da enfermidade, assim como a efetividade das medidas de controle. O estudo compreendeu a micro-região de Dracena, composta por doze municípios, pertencentes à Alta Paulista, Extremo - Oeste do Estado de São Paulo. Os dados analisados foram fornecidos pela Superintendência de Controle de Endemias e Instituto Adolfo Lutz, Laboratório Regional de Presidente Prudente. Foram analisadas, no período compreendido entre agosto de 2005 a janeiro de 2008: as datas de detecção do flebotomíneo nos municípios e o período em que houve o diagnóstico em cães e humanos; o número de casos de óbitos humanos; prevalência de cães suspeitos testados por sorologia; porcentagem de eutanásia em cães suspeitos; se houve correlação entre cães positivos e casos da doença em humanos; comparação das prevalências entre os doze municípios da região estudada. Constatou-se que, apesar das estratégias de controle da LVA adotadas na micro-região de Dracena/SP, a doença continua se expandindo de forma preocupante. Alguns procedimentos do Programa de Vigilância e Controle da LVA devem ser revistos quanto a sua efetividade e outros fiscalizados, para que haja maior credibilidade e eficácia do programa.

Introducción: La coinfección por virus de la hepatitis B (VHB) y VIH afecta a 2,7 millones de personas, que equivale a 5-10% de las personas viviendo con VIH. Esta comorbilidad cambia la historia natural de ambas patologías. En Perú, no están definidas las características de los pacientes VIH según los diferentes patrones serológicos del VHB. Métodos: Estudio transversal analítico secundario de una base de datos obtenida mediante revisión de historias clínicas en dos hospitales públicos de Lima, Perú. Se incluyeron personas con 18 años o más con diagnóstico confirmado de VIH, que iniciaron/reiniciaron tratamiento antiviral de gran actividad (TARGA) 2016-2017. Se evaluaron Antígeno de superficie (HBsAg), Anti-antígeno de superficie (anti-HBs), Anti-antígeno core, y los patrones serológicos según estos marcadores. Se obtuvieron Razones de Prevalencia crudos y ajustados (RPa) para las diferentes características usando regresión de Poisson con varianza robusta. Resultados: Se incluyeron 429 pacientes con una prevalencia de HBsAg de 4,43% (2.69%-6.83%). Existió asociación significativa entre prevalencia de HBsAg y drogas endovenosas (RPa:1,70; IC95% 1,07-2,68), transaminasemia (RPa:3,69; IC95% 2,97-4,57) y uso de TARGA (RPa:0,52; IC95% 0,35-0,77). 129 pacientes sin infección activa fueron evaluados para anti-HBs, siendo positivos 8.53% (4.33%-14.74%). Se encontró asociación con edad ≥30 años (RPa:5,09; IC95% 2,72-9,54), uso de TARGA previo (RPa:3,01; IC95% 1,84-4,93) y carga viral ≥1000 copias/ml (RPa:0,29; IC95% 0,13-0,63). Conclusiones: Uso de drogas endovenosas y transaminasemia se asociaron a mayor prevalencia de infección activa (HBsAg+), mientras que uso previo de TARGA a menor prevalencia. Edad ≥30 años y TARGA se asociaron a mayor prevalencia de anti-HBs en pacientes sin infección activa, y carga viral ≥1000 copias/ml se asoció a menor prevalencia. / Introduction: Hepatitis B virus (HBV) and HIV Co-infection affects 2.7 million people, which is equivalent to 5-10% of people living with HIV. This comorbidity changes the natural history of both pathologies. In Peru, the characteristics of HIV patients according to the different serological patterns of HBV are not well defined. Methods: Secondary analytical cross-sectional study of a database obtained by reviewing medical records in two public hospitals in Lima, Peru. People aged 18 years or older with a confirmed diagnosis of HIV who started/restarted highly active antiviral treatment (HAART) 2016-2017 were included. Surface antigen (HBsAg), Anti-surface antigen (anti-HBs), Anti-core antigen, and serological patterns according to these markers were evaluated. Crude and adjusted Prevalence Ratios (aPR) were obtained for the different characteristics using Poisson regression with robust variance. Results: 429 patients were included with a prevalence of HBsAg of 4.43% (2.69% -6.83%). There was significant association between HBsAg prevalence and intravenous drugs use (aPR: 1.70; 95% CI 1.07-2.68), transaminasemia (aPR: 3.69; 95% CI 2.97-4.57) and prior HAART use (aPR: 0.52; 95% CI 0.35-0.77). 129 patients without active infection were evaluated for anti-HBs, with 8.53% (4.33% -14.74%) being positive. Association was found with age ≥30 years (aPR: 5.09; 95% CI 2.72-9.54), previous HAART use (aPR: 3.01; 95% CI 1.84-4.93) and viral load ≥1000 copies / ml (aPR: 0.29; 95% CI 0.13-0.63). Conclusions: Intravenous drug use and transaminasemia were associated with a higher prevalence of active infection (HBsAg +), while previous use of HAART showed a lower prevalence. Age ≥30 years and HAART were associated with a higher prevalence of anti-HBs in patients without active infection, while viral load ≥1000 copies/ml was associated with lower prevalence. / Tesis

MSc (Microbiology) / Department of Microbiology / Background: Human Herpes Virus-8 (HHV-8) and Human Immunodeficiency Virus (HIV) are endemic in sub-Saharan Africa. However, the prevalence of HHV-8 in HIV-infected individuals in sub-Saharan Africa has not been fully described and characterized. Objectives: The objective of this study was to determine the seroprevalence and genetic subtypes of HHV-8 in an HIV-infected population in Cameroon. Methodology: KSHV/HHV-8 Enzyme-linked Immunosorbent Assay (ELISA) kit (Advanced Biotechnologies Inc., USA) was used to detect IgG antibodies in the plasma of 406 HIV-infected outpatients of the Mutengene Baptist Health Centre, Cameroon. To detect the viral presence, a 233 bp fragment of the ORF 26 gene of HHV-8 was targeted by polymerase chain reaction (PCR) in total DNA purified from patients’ whole blood. A 453 bp of the K1 gene was amplified by nested PCR, sequenced and phylogenetically analysed to infer subtypes. The online tool, Synonymous Non-synonymous Analysis Program (SNAP), was used to determine the rate of synonymous and nonsynonymous mutations in the K1 gene. The genetic variability among the derived K1 nucleotide sequences was determined by mean genetic distance analysis. Results: Of the 406 participants, an HHV-8 seroprevalence of 79.1% was obtained. There was a statistically significant association of seroprevalence with age (p= 0.00), CD4+ cell count (p= 0.02), marital status (p= 0.02) and ownership of a transistor radio set (p= 0.00). Seventy samples (23.3%) were successfully amplified for ORF 26 gene confirming the presence of replicating virus. K1 sequences were obtained for 14 of the 20 (70%) K1 amplified DNAs. The mean genetic diversity of K1 sequences ranges from 0.0%-22.3%. Phylogenetic analysis revealed two infecting viral subtypes in the study cohort: subtype A5 (57.1%), and subtype B (35.7%). Greater positive selection and genetic diversity were observed in A5 subtype compared to B subtype of K1. Interestingly, one sample (BM 547) clustered with an unclassifiable sequence from South Africa. Conclusions and recommendation: This study revealed the endemicity of HHV-8 infection in the studied population, with subtypes A5 and B as the most important epidemiological genetic variants. In addition, targeting the ORF 26 region by PCR could be an approach to detect replicating virus in individuals. Further studies should investigate the association between HHV-8 infection and KS development in the study area which is endemic for HIV. This study contributes data to the HIV/HHV-8 co-infection landscape in the study area and in Africa at large.

MSc (Microbiology) / Department of Microbiology / See the attached abstract below

No description available.

West Nile virus (WNV) infections were first detected in Germany in 2018, but information about WNV seroprevalence in horses is limited. The study’s overall goal was to gather information that would help veterinarians, horse owners, and veterinary-, and public health- authorities understand the spread of WNV in Germany and direct protective measures. For this purpose, WNV seroprevalence was determined in counties with and without previously registered WNV infections in horses, and risk factors for seropositivity were estimated. The cohort consisted of privately owned horses from nine counties in Eastern Germany. A total of 940 serum samples was tested by competitive panflavivirus ELISA (cELISA), and reactive samples were further tested by WNV IgM capture ELISA and confirmed by virus neutralization test (VNT). Information about potential risk factors was recorded by questionnaire and analyzed by logistic regression. A total of 106 serum samples showed antibodies against flaviviruses by cELISA, of which six tested positive for WNV IgM. The VNT verified a WNV infection for 54 samples (50.9%), while 35 sera neutralized tick-borne encephalitis virus (33.0%), and eight sera neutralized Usutu virus (7.5%). Hence, seroprevalence for WNV infection was 5.8% on average and was significantly higher in counties with previously registered infections (p = 0.005). The risk factor analysis showed breed type (pony), housing in counties with previously registered infections, housing type (24 h turn-out), and presence of outdoor shelter as the main significant risk factors for seropositivity. In conclusion, we estimated the extent of WNV infection in the resident horse population in Eastern Germany and showed that seroprevalence was higher in counties with previously registered equine WNV infections.

Les études de séroprévalence portant sur les infections au SRAS-CoV-2 doivent souvent composer avec des échantillons non-aléatoires et non-représentatifs, limitant ainsi parfois la validité externe de leurs résultats lorsque ceux-ci sont appliqués à la population générale. Dans le cadre de ce mémoire, il s’agit d’investiguer la représentativité d’une cohorte pédiatrique d’une étude longitudinale de séroprévalence (Enfants et COVID-19 : Étude de séroprévalence) et d’évaluer dans quelle mesure ses estimations de séroprévalence peuvent s’appliquer à la population pédiatrique montréalaise en général. 1 632 enfants ont fourni au point de départ un échantillon sanguin afin de déterminer leur séropositivité aux anticorps contre le SRAS-CoV-2. À l’aide d’une modélisation par régression logistique et d’un procédé de « standardisation marginale », une pondération post-stratification calculée à partir des données du recensement canadien de 2016 a été appliquée à la population d’étude. Les variations dans les estimations de séroprévalence ont finalement été évaluées. D’importantes différences dans la distribution de certaines caractéristiques sociodémographiques peuvent être observées lorsqu’on compare la population d’étude et la population générale en se basant sur les données du recensement canadien de 2016. En comparaison des estimations non-pondérées, les estimations de séroprévalence générées à partir du procédé de « standardisation marginale » montrent une variation de plusieurs points de pourcentage, allant de -0,4% à +3,2%. La pondération n’a pas induit de changement dans l’estimation de mesures relatives comme les ratios de séroprévalence. Lorsque la population d’étude est non-représentative de la population-cible, il est nécessaire de pondérer les caractéristiques sociodémographiques associées à l’issue si l’on veut appliquer les résultats plus généralement. / Prevalence studies on SARS-CoV-2 infections have often based on study populations with non-random and non-representative samples, which limits the external validity of their results when applied to the general population. The aim of this thesis was to investigate the representativeness of a pediatric cohort of a longitudinal seroprevalence study (Children and COVID-19: Seroprevalence study) and to assess to what extent its baseline estimates of seroprevalence can be applied to the Montreal pediatric population. There were 1 632 children participants who provided a blood sample at baseline, which was used to determine their seropositivity to SARS-CoV-2 antibodies. Using logistic regression modeling and a "marginal standardization" method, post-stratification weights calculated from 2016 Canadian census data were applied to the study population. Variations in seroprevalence estimates were then assessed. Significant differences in the distribution of certain sociodemographic characteristics were observed when comparing the study population and the target population based on 2016 Canadian census data. Seroprevalence estimates were generated from the “marginal standardization” approach which differed to that of the non-standardized estimates, and the differences ranges from -0,4% to +3,2%. Weighting did not change relative measures estimates, such as seroprevalence ratios. When the study population is not representative of the target population, it is necessary to weight the sociodemographic characteristics associated with the prevalence estimates, if the results will be applied more broadly.