Could oral fluid be used to evaluate anti-hepatitis A virus status in individuals living in difficult-to-access areas?

Abstract

A strategy adopted by different countries to reduce the number of new cases of hepatitis A is the vaccination. However, the mosaic of the epidemiological profile in developing countries has hampered the establishment of a unified nationwide vaccination program. To determinate national vaccination policies, the results of epidemiological studies need to be carefully considered. For this monitoring, the use of oral fluid is very important due to the painless and non invasive collection characteristics. There are few studies investigating which oral fluid collection device is optimal to detect low antibody levels and its use in selecting individuals for vaccination. So, the present study aimed to evaluate different oral fluid collection devices to detect humoral immune response against hepatitis A virus and its application in epidemiological studies. Therefore, 90 matched serum and oral fluid samples were collected from volunteers with different immune status, under ideal conditions of collection (optimization panel); and 224 matched samples in difficult-to-access areas (epidemiological study). Serum was collected by venipuncture and the oral fluid was obtained using three commercial devices: Salivette(®), OraSure(®) and ChemBio(®). Serum and oral fluid were submitted to a commercial immunoblot to detect total anti-HAV antibodies. The optimization panel demonstrated that ChemBio(®) device had the best performance (100% agreement), followed by OraSure(®) (95.4%) and Salivette(®) (90.8%). The optimal collection device (ChemBio(®)), tested in a difficult-to-access area and evaluated under precarious conditions of collection, showed similar prevalence of total anti-HAV between serum and oral fluid, 80.8% and 79%, respectively. A follow-up was performed to evaluate the stability of oral fluid and it was observed that 210 days after the collection it was possible to detect anti-HAV antibodies. Oral fluid can be used to detect low levels of specific-antibody, being important to select age groups to be vaccinated. Therewith, the choice of proper collection device is essential to evaluate HAV antibodies in the epidemiological scenario.

A single dose of inactivated hepatitis A vaccine promotes HAV-specific memory cellular response similar to that induced by a natural infection

“…The detection limits of the lots used in the Bioelisa HAV-EIA were 75 mIU/mL (lot L-0407), and 67 mIU/mL (lot I-3308), and the ImmunoComb ® II HAV Ab assay was used at a limit of detection of 10 IU anti-HAV antibodies/L [25].…”

Cross-Sectional Study of Hepatitis A Virus Infection in the Pantanal Population before Vaccine Implementation in Brazil: Usage of Non-Invasive Specimen Collection

“…As demonstrated in this study, oral fluid samples may, in fact, serve as a substitute for blood collection. However, it is important to select the most appropriate device for sample collection and field studies [ 1 , 27 ], providing accurate information to determine the epidemiological profile, the need for immunization and disease control strategies [ 28 ].…”

“…The test was performed according to the manufacturer's instructions and adapted for oral fluid samples by adding 25 µL of oral fluid without sample diluents, as reported by Tourinho et al [ 1 ]. The test results were visible as gray-blue spots on the surface of the projections, and the visual results were determined semi-quantitatively by comparing the intensity of the color of the lower spot on each projection with the color scale provided by the manufacturer.…”

“…Hepatitis A is one of the most frequently reported vaccine-preventable diseases and remains endemic in many areas of the world, especially in developing countries [ 1 ]. Hepatitis A virus (HAV) has been observed in heterogeneous pockets where susceptible or exposed individuals may co-exist.…”

Antibody detection by agglutination–PCR (ADAP) enables early diagnosis of HIV infection by oral fluid analysis

“…The use of oral specimens has facilitated testing in many populations including (i) populations for whom it is inconvenient or unsafe to test using needles (e.g., prisons), (ii) patients whose veins are difficult to draw from (e.g., drug users, infants), and (iii) people who are averse to having blood drawn using needles (e.g., children, adolescents) (10)(11)(12). Furthermore, antibodies in OF are stable for several weeks at ambient temperature, thus decreasing the likelihood of false results when cold chain shipping is not available (13,14). Finally, OF is much safer to handle on a large scale, as HIV cannot be transmitted by OF thanks to significantly lower viral loads and the presence of naturally occurring enzymes and other inhibitors that deactivate the virus (15).…”