Avian anti-HBV immunoglobulin: New tool to improve hepatitis B diagnosis methods.

Immunoglobulin Y (IgY) could be used in serological diagnosis focused on several infectious agents. This study aims to produce IgY anti-hepatitis B virus surface antigen (anti-HBs) and to assess its use in enzyme immunoassays. Antibodies were produced by immunizing chickens with Hepatitis B vaccine associated (group A), or not, with adjuvant CpG-ODN (group B). Eggs were collected for 20 weeks, yolks were purified based on using polyethylene glycol and affinity chromatography. IgY anti-HBs was featured based on SDS-PAGE and Western Blot techniques. Total protein concentration was measured through spectrophotometry. In-house ELISA used to detect HBsAg was developed based on using IgG/HRP conjugate and IgY-anti-HBs sensitized microplates. Thus, IgY anti-HBs were confirmed through molecular pattern based on SDS-PAGE, whereas specificity of anti-HBs was confirmed through Western Blot. Mean total protein reached 3.27 ± 3.00 mg/mL and 3.11 ± 3.12 mg/mL in groups A and B, respectively. In-house ELISA was developed based on using a panel of HBV positive and negative serum samples; it recorded 100 % sensitivity and 78.9 % specificity to detect HBsAg. In conclusion, it was possible producing anti-HBs IgY by immunizing chickens with HBV vaccine; this molecule could be used as capture antibody to help detecting HBsAg in-house ELISA.

Feasibility of dried blood spot for hepatitis C diagnosis in vulnerable subjects and people living in remote areas from Brazil.

BACKGROUND: Agile, accessible and cheap diagnosis of hepatitis C virus (HCV) infection is essential to achieve the elimination of this infection, worldwide, as mandated by the World Health Organzation as part of its strategy for 2030. Dried blood spots (DBS) can be an attractive alternative for sample collection among people living in remote areas and vulnerable populations due to the less invasive collection, its biosafety, and storage & transportation of samples at room temperature. DESIGN: This study aims to estimate the usefulness of dried blood spot samples for the diagnosis and the assessment of HCV infection rates in three different settings in Brazil. Cross-sectional analysis of a sample collection from different populations, aiming to assess the performance of the testing algorithms and respective procedures among different populations with diverse background infection rates. METHODS: We reported the evaluation of DBS as alternative samples for detecting anti-HCV in different groups in real life conditions: (I) Vulnerable subjects living in remote areas of Southeast, North and Northeast Brazil (n = 1464); (II) Beauticians (n = 288); (III) People who use non-injectable drugs (n = 201); (IV) patients referred to outpatient care (n = 275). RESULTS: General assay accuracy was 99%, with a weighted kappa value of 0.9, showing an excellent performance. Sensitivities ranged from 87.5% to 100.0% between groups and specificities were above 99.2%. A total of 194 individuals had HCV RNA in serum and concordance of anti-HCV detection in DBS was 98.4%. CONCLUSIONS: DBS samples could be used for anti-HCV detection in different populations recruited in real life conditions and ambulatory settings, with a high overall sensitivity and specificity.

Dried blood spot sampling as an alternative for the improvement of hepatitis B and C diagnosis in key populations.

BACKGROUND: To achieve the elimination of hepatitis B and C, there is an urgent need to develop alternative strategies to increase the access of diagnosis, particularly among key populations such as people living with human immunodeficiency virus (HIV), individuals with coagulopathies and chronic kidney disease (CKD) patients. AIM: To evaluate the use of dried blood spot (DBS) in the detection of hepatitis B virus (HBV) and hepatitis C virus (HCV) markers. METHODS: A total of 430 individuals comprised of people living with HIV, coagulopathies and CKD provided paired serum and DBS samples. HBsAg, anti-HBc and anti-HCV were tested in those samples using a commercial electrochemiluminescence. Demographic and selected behavioral variables were evaluated to assess possible association with HBV and HCV positivity. RESULTS: Using DBS, HBsAg prevalence varied from 3.9% to 22.1%, anti-HBc rates varied from 25.5% to 45.6% and anti-HCV positivity ranged from 15.9% to 41.2% in key populations. Specificities of HBV and HCV tests using DBS varied from 88.9% to 100%. The HBsAg assay demonstrated the best performance in CKD and coagulopathy individuals and the anti-HCV test had a sensitivity and specificity of 100% in people living with HIV. Accuracy of HBV and HCV detection in DBS varied from 90.2% to 100%. In the CKD group, HBsAg positivity was associated with infrequent use of condoms, and anti-HBc positivity was associated with sharing nail cutters/razors/toothbrushes. Anti-HCV reactivity was positively associated with a history of transplantation and length of time using hemodialysis in both specimens. In people living with HIV, only the male gender was associated with anti-HBc positivity in serum and DBS. CONCLUSION: DBS with electrochemiluminescence are useful tools for the diagnosis and prevalence studies of hepatitis B and C among key populations and may increase the opportunity to foster prevention and treatment.

High prevalence of hepatitis A in indigenous population in north Brazil.

OBJECTIVES: Little is known about hepatitis A virus (HAV) prevalence in indigenous communities. This study aims to evaluate the prevalence of HAV in indigenous community compared to urban population located at Western Amazon in Brazil. RESULTS: A total of 872 serum samples were obtained from 491 indigenous and 381 non indigenous individuals aging 0 to 90 years. Samples were tested for total and IgM anti-HAV and positive IgM samples were tested for HAV RNA. The overall prevalence of total anti-HAV was 87%, increased according age showing 100% of prevalence in those aging more than 30 years (p < 0.0001) and it was similar among indigenous and urban population. Total anti-HAV prevalence varied between tribes (p < 0.0001) and urban sites (p = 0.0014) and spatial distribution showed high prevalence in homes that received up to 100 dollars. IgM anti-HAV prevalence was 1.7% with predominance in males, those aging more than 41 years. No HAV RNA was detected. In conclusion, high overall anti-HAV prevalence was found in indigenous communities in North Brazil demonstrating the importance of universal vaccination in this group.

Epidemiology of hepatitis B and C virus infection in Central West Argentina.

Little information is available regarding the prevalence of viral hepatitis in Central West Argentina. This study aims to give new information regarding HBV and HCV prevalence, genotypes, and risk factors in Central West Argentina and the suitability of dried blood spot (DBS) sampling for HBV and HCV screening. METHODS: A total of 622 individuals were included; the mean age was 36.6 ± 14.3 years and 55.4% were females. HBV and HCV markers were detected using serological and molecular analysis, and risk factors were evaluated using statistical analysis. RESULTS: Using serum samples, the HBsAg prevalence was 1.8%, the rate of HBV exposure (anti-HBc positivity) was 5.3%, and the rate of HBV immunity was 34.9%. HBV DNA was found in four out of 11 HBsAg+ samples, and the viruses in three of these samples were classified as genotypes A1, A2 and F2a. Multivariate analysis showed that anti-HBs positivity was associated with the level of schooling and history of HBV vaccination. The anti-HCV prevalence was 2.6%, and HCV RNA was found in 11 samples, seven of which contained viruses of genotypes 1a (n = 2), 1b (n = 3) and 2 (n = 2). The sensitivity of the DBS assay for HBsAg, anti-HBc, and anti-HCV was 100%, 66.6%, and 75%, respectively, and the specificity was above 98% for all markers when compared to serum. CONCLUSION: A low rate of HBV immunity was observed, demonstrating the importance of HBV vaccination. High HCV prevalence was found, and HCV 1b was closely related to other Argentinian isolates. Finally, the performance of DBS testing in this population needs more optimization to increase its sensitivity and specificity.

Evaluation of accuracy of hepatitis B virus antigen and antibody detection and relationship between epidemiological factors using dried blood spot.

Dried blood spots (DBS) testing might increase the access for Hepatitis B virus (HBV) diagnosis, but little is known about the performance of these assays in real life conditions. This study aims to evaluate the diagnostic accuracy of HBsAg, anti-HBc and anti-HBs detection in DBS in clinical settings and field studies and to evaluate demographic and risk behaviour according the presence of HBsAg and anti-HBc. Paired sera and DBS samples were obtained from 2309 individuals from 3 groups, defined as follows: G1: clinical setting (n = 5-19), G2: general population (n = 1305) and G3: vulnerable individuals that could be more exposed to blood contact (n = 485). Sera and DBS were tested using commercial enzyme immunoassay (EIA), with some modifications added. Using DBS samples, the specificity values were above 90 % for HBsAg and anti-HBc in all groups and for anti-HBs range from 58.6%-85%. HBsAg testing had the best performance in GI (sensitivity = 84.4 %) and among those samples that the paired serum also presented anti-HBc marker (sensitivity = 91.6 %). High sensitivity of anti-HBc testing in DBS samples was observed in GI (80.8 %) and among HBV active cases (HBsAg+/anti-HBc+) (98.4 %). Testing of anti-HBs in DBS showed the highest sensitivity in GIII (65.5 %), in previous HBV exposed and cured individuals and when serum titers were above 100 IU/mL (86.7 %). DBS samples could be used for screening and prevalence studies for HBsAg and anti-HBc, particularly in clinical settings and among HBV active cases in field studies.

Usefulness of automated assays for detecting hepatitis B and C markers in dried blood spot samples.

OBJECTIVE: Dried blood spots (DBSs) can be used as an alternative to serum samples because they are easily collected and can be transported without refrigeration to reference laboratories for diagnosis. The present study was performed to evaluate the utility of electrochemiluminescence immunoassay "ECLIA" for anti-HCV, HBsAg and anti-HBc detection from DBS samples. RESULTS: Anti-HCV was detected in 103 DBS samples from 108 paired, positive serum and undetected in 364 DBS samples from 366 paired, negative specimens, giving a sensitivity of 95.4% and a specificity of 99.4%. HBsAg was detected in 67 DBS samples out of 71 positive, paired serum and was undetected among 295 DBS samples from 298 paired, negative specimens, giving a sensitivity and specificity of 94.4% and 99%, respectively. Anti-HBc was detected in 160 DBS samples from 185 paired, positive serum specimens and undetected in 349 DBS samples from 357 paired, negative serum specimens, giving a sensitivity of 86.5% and a specificity of 97.8%. Overall, the Kappa index indicated a high agreement between results obtained for the serum and DBS samples (k: 0.95, 0.93 and 0.86 for anti-HCV, HBsAg, anti-HBc, respectively). In conclusion, the ECLIA test could be used for detecting hepatitis B and C markers in DBS.

Utility of oral fluid samples for hepatitis B antibody detection in real life conditions.

BACKGROUND: Hepatitis B virus (HBV) testing in oral fluid samples may provide advantages in diagnosis, screening or prevalence studies, especially among individuals with venous access difficulties. This study aims to optimize one commercially available assay for detecting total anti-HBc marker in oral fluid samples and to evaluate its utility under real life conditions in different settings for the purposes of prevalence and diagnostic studies. METHODS: Oral fluid was collected using a Salivette device and some parameters were initially evaluated: type of elution buffer and sample volume. Thereafter, the utility of oral fluid samples for detection of anti-HBc was evaluated in real life conditions in which, 1296 individuals gave serum and oral fluid samples. All serum samples were submitted to commercial EIAs to detect total anti-HBc, according to the manufacturer's instructions and oral fluid samples according to previous optimization. RESULTS: In optimization evaluation, PBS/BSA 0.5% and 100 µL of oral fluid (volume was two-fold increased compared to serum in EIA) were chosen as transport buffer and sample volume. In the field study, anti-HBc was detected in 211 out of 1296 serum samples giving overall oral fluid sensitivity of 52.6% and specificity of 96%. Concordance was higher in ambulatory setting (67.7) compared to general population (31.8). Mean ± standard deviation values of optical density/cutoff (OD/CO) in serum samples were higher in false-negative oral fluid samples than those seen in true positive samples. Sensitivity was higher in those presenting active infection compared to anti-HBc isolate and past infection. Sensitivity also increased in the ambulatory group when HCV individuals were excluded. CONCLUSIONS: It was possible to optimize a commercial EIA for detecting anti-HBc in oral fluid samples and where the highest concordance was found in ambulatory settings and among individuals with active infection.

Applicability of Oral Fluid and Dried Blood Spot for Hepatitis B Virus Diagnosis.

Hepatitis B virus (HBV) is one of the major causes of chronic liver disease worldwide; however most of individuals are not aware about the infection. Oral fluid and dried blood spot (DBS) samples may be an alternative to serum to HBV diagnosis to increase the access to diagnosis in remote areas or high-risk groups. The main objective of this review is to give an insight about the usefulness of oral fluid and DBS for detecting HBV markers. Several groups have evaluated the detection of HBsAg, anti-HBc, and anti-HBs markers in oral fluid and DBS samples demonstrating 13 to 100% of sensitivity and specificity according different groups, sample collectors, and diagnosis assays. In the same way, HBV DNA detection using oral fluid and DBS samples demonstrate different values of sensitivity according type of collection, studied group, extraction, and detection methods. Thus, serological and molecular diagnostic tests demonstrated good performance for detecting HBV using oral fluid and DBS according some characteristics and could be useful to increase the access to the diagnosis of HBV.

Cross-sectional study to determine viral hepatitis knowledge in different urban populations in Brazil.

AIM: To evaluate viral hepatitis knowledge among individuals from different resource areas and health conditions to identify possible gaps. METHODS: A cross-sectional, descriptive study was carried out among 447 individuals from five distinct populations in Brazil: Southeast Viral Hepatitis Ambulatory (n = 100), South (n = 89) and Northeast (n = 114) Health Center, Southeast (n = 77) and Northeast (n = 67) low resource areas. All individuals answered a questionnaire assessing sociodemographic characteristics and viral hepatitis awareness. The perception was scored based on the average number of correct answers of all participants and categorized as "low" (0-28 correct answers) or "desirable" (29-46 correct answers). Associations between sociodemographic characteristics and perception were also evaluated. RESULTS: A low level of knowledge was observed in individuals from Northeast Health Center, Northeast and Southeast low resource areas while desirable knowledge was observed in individuals from Viral Hepatitis Ambulatory and South Health Center. According to sociodemographic characteristics, desirable scores were more common among those with secondary education (47.1%), those who declared themselves as white (46.3%), and those who lived in houses with three individuals (25.5%). Multivariate analysis showed an association between viral hepatitis perception and type of population. CONCLUSION: The results demonstrated high level of knowledge among study participants from health clinics from the Southeast region of Brazil and the importance of education programs in increasing the level of knowledge in low resource areas.

Assessing hepatitis B immunity using dried blood spot samples from HIV+ individuals.

This study aims to evaluate the utility of an optimized enzyme immunoassay (EIA) to detect and quantify antibodies against hepatitis B surface antibody (anti-HBs) in dried blood spots (DBSs) within the context of human immunodeficiency virus (HIV) status. Serum and DBS samples were obtained from 56 HIV+ and 99 HIV- patients and subjected to EIA for the detection of anti-HBs, where sample volume and cut off value were modified for DBS testing. Sensitivities of anti-HBs detection in DBS were 79.8% and 76.8% in HIV- and HIV+ subjects, respectively. Concordant results for anti-HBs in serum and DBS presented high mean CD8 cell counts, HIV viral load and optical density (OD) values of anti-HBs. Anti-HBs titers were significantly higher in serum, whether or not anti-HBs titers were detected in DBS. It was possible to detect anti-HBs in DBS as low as 17.4 and 27.3 IU/mL among HIV+ and HIV- subjects, respectively. In conclusion, DBS can be used to detect and quantify anti-HBs in HIV-infected individuals, which could increase access to diagnosis and vaccination.

Determination of hepatitis B, C and D prevalence among urban and Amerindian populations from the Eastern Brazilian Amazon: a cross sectional study.

BACKGROUND: This study was conducted to determine the prevalence of HBV, HCV, and HDV in urban populations and Amerindians living in the state of Tocantins (Eastern Amazon). METHODS: A total of 948 individuals were recruited in Tocantinopolis city (Tocantins state) of whom 603 were Amerindians (from 6 tribes) and 345 were non-Amerindians (6 urban areas of Tocantinópolis city). Anti-HCV, HBsAg, anti-HBc, anti-HBs, anti-HBc IgM, anti-HBe, HBeAg, and anti-delta antibodies were determined using enzyme immunoassay. RESULTS: HBV cleared infection (both anti-HBc/anti-HBs+), chronic inactive/immune controlled HBV infection (anti-HBc + only), previous HBV vaccination (anti-HBs + only), active HBV infection (HBsAg+), individuals susceptible to HBV, and anti-HCV reactivity were found in 12.9, 1.8, 27.2, 0.5, 57.7, 1.2% in Amerindians and 12.1, 2.0, 37.1, 0.3, 55.4, 0.3% in non-Amerindians respectively. Out of 139 anti-HBc reactive individuals, 70 were anti-HBe reactive and none presented HBeAg or anti-HBc IgM. Anti-HBc prevalence was associated to older age (p < 0.0001). Overall anti-Delta prevalence was 0.3% and regarding anti-HBc reactive individuals, anti-delta prevalence was 3.4 and 0% in Amerindians and non-Amerindians respectively. CONCLUSIONS: Overall low prevalence of HBV and HCV infection was found in the populations studied, but high HBV and HCV prevalence was observed in Amerindians compared to non-Amerindians suggesting that these individuals have a higher likelihood of acquiring to these infections. Anti-delta antibodies were found among Amerindians from Eastern Amazon suggesting a risk for this population. Of note is that nearly half of Amerindians had no anti-HBs, indicating a need for HBV vaccination campaigns in this population.

Comparison of the performance of enzyme immunoassays for hepatitis B and C detection in dried blood spot.

Dried blood spots (DBSs) could be an alternative to serum for hepatitis B virus (HBV) and hepatitis C virus (HCV) diagnosis. This study aims to evaluate two enzyme immunoassays (EIAs) for HBsAg and anti-HCV detection using DBS. Serum was tested using commercial EIA. DBS was tested using optimized EIA developed for serum and commercial EIA developed for DBS (Imunoscreen). Concordances between DBS and serum samples for both markers and EIAs were higher than 97%. Both EIAs demonstrated good performance for HBsAg and anti-HCV detection using DBS, and these methods could be used unchangeably increasing the access for HBV and HCV diagnosis.

A Cross-Sectional Study of Viral Hepatitis Perception among Residents from Southeast and North Regions of Brazil.

Few data are available regarding viral hepatitis perception among the general global population. The present study aims to estimate the perception of viral hepatitis in a cohort of individuals living in two geographical regions of Brazil: North (Manaus city (MA)) and Southeast (Rio de Janeiro city (RJ)). A cross-sectional, descriptive study was carried out among 287 subjects recruited in MA (134) and RJ (153). All individuals answered a questionnaire assessing socio-demographic characteristics and viral hepatitis awareness. Participants' responses were scored and divided using interquartile values. Associations between socio-demographic characteristics and knowledge were also evaluated. Interquartile analysis scored 0-21 correct answers as "Very Weak"; 22-27 as "Weak"; 28-31 as "Intermediate"; and 32-47 as "Desirable". Mean ± standard deviations (SD) of correct responses were weak in both MA (24.1 ± 7.0) and RJ (26.3 ± 7.3). Bivariate analysis showed an association between viral hepatitis awareness and both education level (p < 0.001) and family income (p < 0.01). Desirable scores were more common in female participants (61%), those aged between 21-30 years (40%), those with a secondary education (51.7%), those who received high income (31.6%), and those from RJ (70.0%). Health education campaigns in these cities are recommended to increase knowledge and reduce the transmission of these viruses.

Uso de fluido oral e sangue seco em papel de filtro como espécimes clínicos para incremento do diagnóstico e estudo de prevalência da hepatite B e avaliação do nível do conhecimento sobre as hepatites virais em diferentes grupos no Brasil / Use of oral fluid and dried blood on filter paper as clinical specimens for further diagnosis and study of hepatitis B prevalence and assessment of the level of knowledge about viral hepatitis in different groups in Brazil

A utilização de amostras alternativas ao soro, bem como a avaliação do nível de conhecimento sobre as Hepatites Virais (HV) poderiam contribuir no aumento do acesso ao diagnóstico do vírus da hepatite B (HBV) e elaboração de planos para prevenção e controle das HVs. O objetivo deste trabalho foi determinar a aplicabilidade do uso de fluido oral e sangue seco em papel filtro (SSPF) para a detecção do HBV em áreas de difícil acesso, bem como avaliar a percepção sobre HVs em diferentes grupos. Na avaliação dos testes de diagnóstico para HBV, três grupos foram incluídos: G1) Alta prevalência, G2) Baixa prevalência e G3) Indivíduos com vulnerabilidade para aquisição de HBV. Foram obtidas 1296 amostras pareadas de fluido oral e soro para avaliação do desempenho da detecção do marcador anti-HBc e 2309 amostras pareadas de SSPF e soro para avaliação do desempenho da detecção de HBsAg, anti-HBc e anti-HBs. Também foram avaliados o teste comercial otimizado e teste comercial próprio para detecção do HBsAg em SSPF. Para avaliar o conhecimento sobre HV, dois estudos foram realizados utilizando um instrumento de coleta de dados. O primeiro estudo foi composto por 247 participantes em um evento de saúde na região Sudeste e moradores de uma cidade do Norte do País enquanto o segundo foi composto por 447 indivíduos provenientes de cinco diferentes populações: ambulatório de HV da região Sudeste; Centro médico das regiões Sul e Nordeste, e comunidades carentes das regiões Sudeste e Nordeste.

O teste de detecção de anti-HBc em fluido oral e SSPF e de HBsAg em SSPF apresentou melhor desempenho no grupo de alta prevalência (67,7%; 75,5%; 77,3%, respectivamente); também houve boa concordância do SSPF com o soro entre indivíduos vulneráveis na detecção do anti-HBc (75,2%). O teste de detecção de anti-HBs em SSPF apresentou baixo desempenho em todos os grupos avaliados (<44,5%). O teste de anti-HBc em fluido oral e em SSPF apresentou maior sensibilidade quando considerados os indivíduos com infecção ativa (92,7%; 98,4%, respectivamente). O teste de detecção de anti-HBs em SSPF apresentou maior sensibilidade entre indivíduos com altos títulos de anticorpo. Observamos bom desempenho do teste de detecção de HBsAg em SSPF pelo EIE comercial otimizado e EIE próprio. Foi observado baixo nível de conhecimento sobres as HVs entre indivíduos de Manaus e RJ no estudo 1 e indivíduos do Centro médico de Fortaleza e comunidades carentes no estudo 2. Por outro lado, conhecimento desejável foi observado em ambulatórios da região Sudeste e Sul do Brasil. Concluimos que o fluido oral e SSPF podem ser empregados como alternativa ao soro na detecção dos marcadores HBsAg e anti-HBc em estudos de prevalência para HBV, especialmente em grupos com infecção ativa. O teste anti-HBs em SSPF não foi uma boa alternativa para avaliar a imunidade da infecção pelo HBV. O conhecimento sobre HVs observado indica que há necessidade de aumentar o acesso à educação, e promover campanhas de educação em saúde, especialmente entre indivíduos de comunidades carentes e com menor escolaridade. (AU)

Prevalence of Hepatitis B and C virus infection among alcoholic individuals: importance of screening and vaccination.

Drug users have been reported to have an increased risk for acquisition of viral hepatitis. This study aims to evaluate the prevalence of HBV and HCV infection and usefulness of saliva for HBsAg and anti-HCV detection in alcoholic patients.A total of 90 alcoholic patients were recruited in 2013. HBsAg and anti-HCV were tested in serum and saliva, anti-HBc and anti-HBs were tested in serum using commercial enzyme immunoassays (EIA).Using serum samples, anti-HCV, HBsAg, anti-HBc and anti-HBs prevalences were 5.6%, 0%, 15.7%, and 29.2%. HBsAg detection in saliva showed 100% of specificity and anti-HCV detection demonstrated 100% of sensitivity and 94.7% of specificity. Low prevalence of HBV and high prevalence of anti-HCV were found and reinforced the recommendation of HBV vaccination to avoid the acute and chronic cases and HCV screening in this group to identify cases for antiviral therapy. Saliva samples could be used for anti-HCV detection in this population, what could increase the diagnosis access.

Evaluation of HBsAg and anti-HBc assays in saliva and dried blood spot samples according HIV status.

Influence of HIV status in HBV markers detection in saliva and dried blood spots (DBS) was not well established. This study aims to evaluate the performance of optimized commercial immunoassay for identifying HBsAg and anti-HBc in saliva and DBS according HIV status. A sum of 535 individuals grouped as HIV+, HBV+, HIV/HBV+ and HIV/HBV- were recruited where 347 and 188 were included for HBsAg and anti-HBc evaluation, respectively. Serum, DBS collected in Whatman 903 paper and saliva obtained using salivette device were analyzed using EIA. Increased sample volume and ROC curve analysis for cut off determination were used for DBS and saliva testing. HBsAg detection in saliva and DBS exhibited sensitivities of 80.9% and 85.6% and specificities of 86.8% and 96.3%. Sensitivity of anti-HBc in saliva and DBS were 82.4% and 76.9% and specificities in saliva and DBS were 96.9% and 91.7%. Low sensitivities were observed for HBsAg (62%) and anti-HBc (47%) detection in saliva of HIV/HBV+ individuals. OD values were also lower for HBsAg detection in DBS and saliva of HIV/HBV+ individuals compared to their serum samples. Statistical significance was found for sensitivities in HBsAg detection between saliva and DBS demonstrating high sensitivity for DBS specimens. In conclusion, HIV status or antiretroviral treatment appears to interfere in the performance of HBsAg and anti-HBc detection in DBS and saliva samples using the adapted commercial EIA.

Poor sensitivity of rapid tests for the detection of antibodies to the hepatitis B virus: implications for field studies

Rapid tests (RTs) can be used as an alternative method for the conventional diagnosis of hepatitis B virus (HBV). This study aims to evaluate antibodies to HBsAg (anti-HBs) and antibodies to HBeAg (anti-HBe) RTs under different Brazilian settings. The following three groups were included: GI: viral hepatitis outpatient services; GII: low resource areas; and GIII: crack users and beauticians. Imuno-rápido anti-HBsAg™ and Imuno-rápido anti-HBeAg™ RTs were evaluated and showed specificities greater than 95% in all groups. The sensitivity values to anti-HBs were 50.38%, 51.05% and 46.73% and the sensitivity values to anti-HBe were 76.99%, 10.34% and 11.76% in the GI, GII and GIII groups, respectively. The assays had a low sensitivity and high specificity, which indicated their use for screening in regions endemic for HBV.

Performance of ANTI-HCV testing in dried blood spots and saliva according to HIV status.

The use of saliva and dried blood spots (DBS) could increase access to HCV diagnosis for high-risk populations, such as HIV-infected individuals, but the performance of these assays has not been well established in this group. This study aims to evaluate HIV status, particularly TCD4+ cell count and viral load, in the performance of anti-HCV testing using DBS and saliva. A total of 961 individuals classified as HCV+, HIV+, or HIV/HCV+, as well as negative controls, donated serum, DBS, and saliva samples for anti-HCV testing using a commercial enzyme immunoassay. Sample volume was modified for DBS and saliva, and an ROC curve was used for cut-off determination in saliva. Anti-HCV sensitivities were greater than 93% using DBS and saliva in the HCV+ group, while they were 83.3% and 95.6% for HCV/HIV+ individuals for DBS and saliva assays, respectively. Specificity varied from 91.7% to 100% using saliva and DBS in HIV monoinfected and control subjects. When only anti-HCV/HCV RNA+ serum samples, that is, true positives, were considered, the sensitivities were 98.3% and 100% for DBS and saliva, respectively, in the HCV+ group and 91.6% and 94.8% for DBS and saliva, respectively, in the HIV/HCV+ group. High absorbance values were observed among those presenting with HCV RNA in serum and low HIV viral load (less than 50 copies/mL). In conclusion, DBS and saliva samples could be used for anti-HCV detection, particularly to identify active HCV cases, but low sensitivity was observed for anti-HCV testing using DBS in the HIV/HCV+ group.

Poor sensitivity of rapid tests for the detection of antibodies to the hepatitis B virus: implications for field studies.

Rapid tests (RTs) can be used as an alternative method for the conventional diagnosis of hepatitis B virus (HBV). This study aims to evaluate antibodies to HBsAg (anti-HBs) and antibodies to HBeAg (anti-HBe) RTs under different Brazilian settings. The following three groups were included: GI: viral hepatitis outpatient services; GII: low resource areas; and GIII: crack users and beauticians. Imuno-rápido anti-HBsAg™ and Imuno-rápido anti-HBeAg™ RTs were evaluated and showed specificities greater than 95% in all groups. The sensitivity values to anti-HBs were 50.38%, 51.05% and 46.73% and the sensitivity values to anti-HBe were 76.99%, 10.34% and 11.76% in the GI, GII and GIII groups, respectively. The assays had a low sensitivity and high specificity, which indicated their use for screening in regions endemic for HBV.