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Objectives The immune trypanolysis test ( TL) is an accurate sero-diagnostic tool increasingly implemented for sleeping sickness medical surveillance, but it is restricted to the reference laboratories. To facilitate storage and transport of the test specimen, we developed a protocol for the examination of blood spotted on filter paper ( TL-fp) that can be stored and shipped at ambient temperature. We compared its performance with the classical TL on plasma ( TL-pl) that needs to be kept frozen until use. Methods The study was conducted in active foci of the Republic of Guinea. In total, 438 specimens from treated and untreated sleeping sickness patients and serological suspects were tested with both methods. Result TL-fp gave significantly less positive results than TL-pl, but all the confirmed sleeping sickness cases were positive with the TL-fp protocol. Conclusion TL-fp appears to offer a good compromise between feasibility and sensitivity to detect currently infected subjects who play a role in the transmission of Trypanosoma brucei gambiense and is useful for contributing to the elimination of gambiense sleeping sickness. [ABSTRACT FROM AUTHOR]

The use of dry blood spots (DBS) on filter paper has become of increasing interest in the field of immunoassay over the last years due to the advantages this mode of presentation brings, enabling its use in countries where resources are scarce or limited to accomplish epidemiological studies. In this work, the optimal conditions for the elution of dry blood spots (3 mm disks) collected on filter paper were determined. Serum samples and the elution conditions establish for 5 mm disks were taken as reference in the detection of specific antibodies to Trypanosoma cruzi by using the indirect UMELISA® CHAGAS (International Tecnosuma S.A.) immunoassay based on Ultra Micro Analytic System (SUMA®). Twelve sero-positive serum samples for Chagas disease from Colombia were confirmed by indirect immunofluorescence (IFI) and ELISA -- Chagatek®, and 75 DBS on filter paper from Bolivia reactive by UMELISA® CHAGAS were evaluated. Additionally, serum samples and DBS negative to Chagas disease from healthy donors from Havana Province Blood Bank were tested. The sensitivity and specificity study results for 3 mm and 5 mm disks were similar. Reduction of the disk diameter allows increasing the number of diagnostic tests, from a very same spot, for the detection of other disease such as the acquired immunodeficiency syndrome, hepatitis B and C, among others. [ABSTRACT FROM AUTHOR]

Objectives. To estimate the prevalence of antibodies against measles, rubella and hepatitis B in children aged between 1 and 4 years in Peru. Materials and methods. A national survey was conducted based on a questionnaire and capillary blood sample taken on filter paper in order to study antibodies against measles, rubella and hepatitis B in children from 1 to 4 years of age. A stratified, multistage, probability sampling design was used to be representative at the national level and at level of seven ambits, including the Metropolitan Lima Area, the rest of the urban coast, the rural coast, the urban highlands, the rural highlands, the urban jungle and the rural jungle. The capillary blood samples were processed according to the standardized protocols for detection of antibodies using the ELISA technique and commercial reagents. Results. The survey showed a national prevalence of antibodies against measles, rubella and hepatitis B of 91.6% (CI 95%: 90.6%; 92.7%), 91.3% (CI 95%: 90.3%; 92.4%) and 95.9% (CI 95%: 95.0%; 96.8%) respectively. There was no evidence of significant differences in the prevalence among the ambits of study or among the socioeconomic strata of the conglomerates for any of the three types of antibodies. Conclusions. In children from 1 to 4 years of age, the national prevalence of antibodies against measles and Rubella was between 90-93%, while the prevalence of antibodies against Hepatitis B (anti-HBsAg) was between 95-97%. [ABSTRACT FROM AUTHOR]

In this paper the concept of hapten is discussed , as well as the most used methods for conjugation of haptens (carboxylic acids, amines, nitro compounds, alcohols, phenols, carbohydrates, aldehydes and ketones) to carrier proteins. At present these hapten-carrier protein conjugates are useful as immunogens for obtaining polyclonal and monoclonal antisera employed in the production of immunodiagnostic reagents which represent one of the main Biotechnology applications. [ABSTRACT FROM AUTHOR]

Production of specific antibodies against compounds of low molecular weight (antibodies antihaptens) require the design of an immunization scheme employing as immunogen.a convenient synthetized hapten-carrier protein conjugate. A large number of organic compounds has been used as haptens, for example carboxylic acids as vanilmandelic acid (VMA), homovanillinic acid (HVA), palmitic acid, stearic acid and oleic acid, amines as norepinephrine, epinephrine, and metanphetamine, opium alkaloids as thebaine, codeine, morphine and cocaine, vitamins such as vitamin A, vitamin D3, vitamin B12, and biotine (vitamin H). Methods of preparation and characterization of hapten-carrier protein conjugates, and the evaluation of their immunogenic properties are described in this paper. [ABSTRACT FROM AUTHOR]