Biomaterial Database

Detection of sporozoites of Plasmodium vivax and Plasmodium falciparum in mosquitoes by ELISA: false positivity associated with bovine and swine blood. 1993

P Somboon, and N Morakote, and S Koottathep, and U Trisanarom

Department of Parasitology, Faculty of Medicine, Chiang Mai University, Thailand.

Blood samples from cows and pigs were tested for possible cross-reactivity with a monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) kit designed for detection of human malaria sporozoites in mosquitoes. The results revealed that 4 of 16 cows (25%) reacted positively with both Plasmodium falciparum (2A10) and P. vivax (NSV3) monoclonal antibodies and 8 (50%) were positive with NSV3 only. One of 12 pigs (8.33%) was positive with both antibodies, and 2 (16.6%) were positive with NSV3 only. The positivity was associated with plasma, but not with the blood cell fraction. Antigenic extracts of Sarcocystis, Toxoplasma gondii and Trypanosoma evansi gave negative ELISA results, suggesting that these were not the factors in animal blood which gave positive results. Laboratory Anopheles dirus A fed on blood of a positive cow by membrane feeding also gave a positive ELISA result. Furthermore, some blood-fed culicine mosquitoes collected directly from a positive cow were ELISA-positive. The cross-reactive factor(s) in plasma has (have) not yet been identified. These false positive ELISA results could complicate the assessment of sporozoite rate in mosquito populations if the study were carried out by ELISA only, especially in areas where cattle and swine are present.

UI	MeSH Term	Description	Entries
D010963	Plasmodium falciparum	A species of protozoa that is the causal agent of falciparum malaria (MALARIA, FALCIPARUM). It is most prevalent in the tropics and subtropics.	Plasmodium falciparums,falciparums, Plasmodium
D010966	Plasmodium vivax	A protozoan parasite that causes vivax malaria (MALARIA, VIVAX). This species is found almost everywhere malaria is endemic and is the only one that has a range extending into the temperate regions.	Plasmodium vivaxs,vivax, Plasmodium
D004797	Enzyme-Linked Immunosorbent Assay	An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.	ELISA,Assay, Enzyme-Linked Immunosorbent,Assays, Enzyme-Linked Immunosorbent,Enzyme Linked Immunosorbent Assay,Enzyme-Linked Immunosorbent Assays,Immunosorbent Assay, Enzyme-Linked,Immunosorbent Assays, Enzyme-Linked
D005189	False Positive Reactions	Positive test results in subjects who do not possess the attribute for which the test is conducted. The labeling of healthy persons as diseased when screening in the detection of disease. (Last, A Dictionary of Epidemiology, 2d ed)	False Positive Reaction,Positive Reaction, False,Positive Reactions, False,Reaction, False Positive,Reactions, False Positive
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000852	Anopheles	A genus of mosquitoes (CULICIDAE) that are known vectors of MALARIA.	Anopheles gambiae