ABSTRACT
Blood platelets are the innate immune elements that have not been investigated in human filarial infections. Platelet activation status in the endemic normals (EN), microfilaria positive individuals (MF) and patients with chronic pathology (CP) was evaluated in whole blood, under unstimulated as well as antigen exposed (BmA, E. coli) conditions for PAC-1 expression by Flow cytometry. A diminished PAC-1 expression was observed in MF compared to CP and EN spontaneously as well as upon antigen exposure. Besides this, PAC-1 expression within the groups did not exhibit any significant difference under all the experimental conditions. However in CP patients, E. coli antigen exposure resulted in a significantly reduced PAC-1 expression compared to the spontaneous expression levels. NO release in platelet culture supernatants from EN was inversely proportional to platelet aggregation. Collagen stimulated platelets from EN, exposed to sera and immune complexes from CP and MF patients resulted in elevated Nitric Oxide (NO) release, compared to those exposed to autologous sera and fetal calf serum. In addition, under similar conditions, collagen stimulated platelets from EN, exposed to filarial antigen (BmA) exhibited increased NO compared to the E. coli antigen exposed ones and light microscopic observations of cultured platelets supported the above findings. Thus it appears from the results of the present study that filarial antigen may play a role in the loss of platelet aggregation, leading to platelet inactivation.
Subject(s)
Filariasis/blood , Platelet Activation , Wuchereria bancrofti/physiology , Adolescent , Adult , Animals , Antibodies, Helminth/blood , Antigens, Helminth/blood , Child , Female , Filariasis/parasitology , Fluorescein-5-isothiocyanate , Fluorescent Dyes , Humans , Male , Microscopy, Fluorescence , Middle Aged , Nitric Oxide/metabolism , Wuchereria bancrofti/immunology , Young AdultABSTRACT
BACKGROUND & OBJECTIVE: In the tsunami (December 2004) affected coastal villages located on southern parts of Coramandel Coast of India, seawater intrusion has created serious problems for the people. In order to assess the risk of outbreak of fly-borne diseases, a longitudinal study for one year was carried out to investigate muscoid fly abundance and their distribution in relation to various phases of relief measures in disaster-hit villages. METHODS: Muscoid fly density was monitored in devastated human settlements, temporary shelters, garbage dumping yards and open defaecation yards in seawater intrusion and indoors and outdoors of seawater non intrusion areas using scudder grill and sweep net at monthly intervals from February 2005 to January 2006. RESULTS: Muscoid fly density recorded in the seawater incursion area was significantly higher, compared to that observed in the seawater non incursion area with scudder grill sampling (F= 57.896, df = 1, P<0.01) or sweep net sampling (F= 63.6, df = 1, P<0.01). Fly density in seawater non incursion area was higher during hotter months (June-July 2005) and lower during cooler months. On the contrary, the fly density in the seawater incursion areas was higher during the cooler months than in hotter months, indicating that the normal trend was upset by the tsunami. INTERPRETATION & CONCLUSION: Seawater incursion, crowding of tsunami victims at relief camps, accumulation of solid waste at centralized relief kitchen and temporary shelters were responsible for the sudden increase in the number of flies. However, the post-disaster relief efforts kept the situation under control, without outbreak of any vector-borne diseases.
