Testing of newly developed glycophospholipid antigen for the detection of P. falciparum malaria by laser light immunoassay in endemic and non-endemic areas.

A glycophospholipid (GPL) antigen isolated from Plasmodium falciparum culture supernatant has been tested for its antigenicity. Detection of malaria positive known blood samples and unknown field samples from endemic and non-endemic areas were compared. In this study laser light scattering immunoassay (LIA) was used for the detection of P. falciparum malaria. Test results of control (malaria negative samples from Surat) were compared with known positive samples and unknown malaria positive field samples. A positive correlation has been observed (97%) in falciparum positive samples from laboratory and unknown samples from endemic area (Haldwani) by LIA method using GPL antigen. From the results of the study it was found that GPL antigen has a better antigenic property and can detect almost all the cases of Pf malaria by LIA method.

Effect of serum dilution in diagnosis of malaria in community.

Recently, it has been shown that immunological methods can be used for the diagnosis of malaria other than sero-epidemiology. A study has been done to investigate optimum binding capacity of antigen-antibody (Ag-Ab) at different serum dilutions. For validating antigen-antibody (Ag-Ab) reaction at 1:100, 1:1000 and 1:1000 serum dilutions, have been tested in two different laboratories to establish validation of the ELISA method. Inter laboratory test on synthetic peptide (RI) ELISA was found comparable and meaningful for assessing malaria transmission in defined locality at 1:100 dilution. Results also showed that 1:1000 serum dilution can be useful for diagnostic purpose.

Well-breeding Anopheles dirus and their role in malaria transmission in Myanmar.

Mosquitos were collected with human and animal baits from March 1996 to January 1998 in four villages located along the Yadana gas pipe line in Yepyu township, Dawae district, Tanintharyi Division, southern Myanmar. A total of 23 anopheline species were collected. Anopheles dirus were abundant in pre-monsoon (May/June) an post-monsoon (October) months. All An. dirus caught both humans and cattle were assayed with specific, sporozoite enzyme-linked immunosorbent assays (ELISAs). A total of 5/250 (2%) caught with human bait was found positive with Plasmodium vivax from Eindayaza, Ohnbinkwin and Thaechaung during rainy and cool-dry months. Larval surveys also showed An. dirus larvae/pupae were caught from domestic wells (6 to 46% found positive). Clinical surveys indicated that transmission is hyperendemic and occur all year round in all four villages.

The effect of tetanus toxoid in leprosy patients.

Since cases of lepra reaction following smallpox vaccination and BCG vaccination had been reported the effect of tetanus immunisation on leprosy patients (whether it may provoke a lepra reaction or not) was studied. Three doses of purified tetanus toxoid (one ml initially, one ml after six weeks and one ml after six months) were given to 357 leprosy patients and 60 patients living in the same environ were followed as controls. The antibody response following immunisation was followed in six lepromatous leprosy patients using toxin antitoxin neutralisation test at the Lf/1000 level in mice and in three of them the antibody titre of leprosy patients rose to satisfactory level. The number of lepra reactions in these patients was monitored for nine months (two months before vaccination, during the six months period of vaccination and one month after the last dose of vaccine). There was no significant rise in the number of patients with reaction following the vaccination.

Active immunization against tetanus III. Results of a five year study.

This is the first time in Burma that tetanus toxoids (purified and adsorbed) have been tested in over 250 non-immune adult volunteers and studied for a period of nearly five years. The safety and efficacy of these toxoids have been assessed by immunological, statistical and clinical methods. Both toxoids were found to be safe. The adsorbed toxoid was far superior to the fluid toxoid as an immunizing agent and optimum immunization regimens are proposed and presented.

Pre-exposure prophylaxis of humans against rabies: I. Studies on personnel at the Burma Pharmaceutical Industry.

This is the first time in Burma where personnel at risk against rabies have been pre-immunized and the effectiveness of such a procedure has been studied for nearly two years. The first batch of lyophilized, Semple-type, beta propiolactone inactivated anti rabies vaccine produced by the Burma Pharmaceutical Industry (B.P.I.) was used to immunize 55 B.P.I. workers previously unexposed to rabies and with no history of rabies vaccination. Three doses of 0.25 ml of the vaccine were given intradermally at one week intervals. Booster doses were given on the 98th, 392nd and 592nd day after the first dose. Blood samples were taken and serum neutralization tests were performed at varying time intervals after basic immunization and booster doses. Satisfactory antibody responses were obtained. The course of immunological response is presented and discussed.