Minimising invasiveness in diagnostics: developing a rapid urine-based monoclonal antibody dipstick test for malaria.

OBJECTIVE: To generate monoclonal antibodies (MAbs) for developing a rapid malaria diagnostic urine-based assay (RUBDA), using Plasmodium-infected human urinary antigens. METHODS: Plasmodium-infected human urinary (PAgHU) and cultured parasite (CPfAg) antigens were used to generate mouse MAbs. The reactivity and accuracy of the MAbs produced were then evaluated using microplate ELISA, SDS-PAGE, Western blotting assay, microscopy and immunochromatographic tests. RESULTS: Ninety-six MAb clones were generated, of which 68.8% reacted to both PAgHU and CPfAg, 31.3% reacted to PAgHU only, and none reacted to CPfAg only. One promising MAb (UCP4W7) reacted in WBA, to both PAgHU and CPfAg, but not to Plasmodium-negative human urine and blood, Schistosoma haematobium and S. mansoni antigens nor measles and poliomyelitis vaccines. CONCLUSION: MAb UCP4W7 seems promising for diagnosing Plasmodium infection. Urine is a reliable biomarker source for developing non-invasive malaria diagnostic tests. SDS-PAGE and MAb-based WBA appear explorable in assays for detecting different levels of Plasmodium parasitaemia.

Immunolocalization of the 29 kDa Schistosoma haematobium species-specific antigen: a potential diagnostic marker for urinary schistosomiasis.

BACKGROUND: The 29 kDa Schistosoma haematobium species-specific antigen (ShSSA) is of remarkable interest in the diagnosis of urinary schistosomiasis although it had not been fully characterized. METHOD: To determine the biological importance of ShSSA in S. haematobium and pathogenesis of the disease, we immunolocalized ShSSA in schistosome eggshells, miracidia and adult worm sections using indirect fluorescent antibody test (IFAT). RESULTS: ShSSA was strongly immunolocalized in the schistosome eggshells, selective regions of the miracidia body and walls of internal organs such as oviduct, ovary, vitelline duct and gut of the adult worm. CONCLUSION: The strong immunolocalization of ShSSA in schistosome eggshells and adult worm internal organs suggests that the antigens involved in the pathogenesis of urinary schistosomiasis could have originated from the eggs and adult worms of the parasite. The findings also indicate that ShSSA may play a mechanical protective role in the survival of the parasite.

Motivations for food prohibitions during pregnancy and their enforcement mechanisms in a rural Ghanaian district.

BACKGROUND: Food taboos are known from virtually all human societies and pregnant women have often been targeted. We qualitatively assessed food taboos during pregnancy, its motivating factors, and enforcement mechanisms in the Upper Manya Krobo district of Ghana. METHODS: This was an exploratory cross sectional study using qualitative focus group discussions (FGDs). Sixteen FGDs were conducted. Participants were purposively selected using the maximum variation sampling technique. Tape recorded FGDs were transcribed verbatim and analyzed using Malterudian systematic text condensation technique. RESULTS: All the participants were aware of the existence of food prohibitions and beliefs targeting pregnant women in Upper Manya Krobo. The study identified snails, rats, hot foods, and animal lungs as tabooed during pregnancy. Adherence motivators included expectation of safe and timely delivery, avoidance of "monkey babies" (deformed babies); respect for ancestors, parents, and community elders. Enforcement mechanisms identified included constant reminders by parents, family members and significant others. Stigmatization and community sanctions are deployed sparingly. CONCLUSIONS: Food taboos and traditional beliefs targeting pregnant women exist in Upper Manya Krobo. Pregnant women are forbidden from eating snails, rats, snakes, hot foods and animal lungs. To a large extent, socio-cultural, and to a lesser, health concerns motivate the practice.