Indian journal of malariology最新文献

Relapse pattern in P. vivax malaria was studied in five villages of Nadiad taluka, Kheda district, Gujarat. P. vivax cases treated with 600 mg chloroquine and in combination with 50 mg pyrimethamine (adult dose) yielded 28.31 and 27.73% relapse rate respectively. While relapse rate of 5.78% was observed with five day course of 75 mg primaquine (15 mg/day) administered as radical treatment. Relapse rate in 5-10 yr of age group was comparatively more than other age groups. There was no noticeable difference in relapse rates among male and female. The short-term relapse with a lag period of 2-3 months was significantly higher in this area. The longest relapse with an interval of 17 months was found in one case treated with chloroquine along with pyrimethamine. However, primaquine regimen prevented consecutive relapses. Primaquine has been found adequate to prevent relapse in more than 90% vivax cases, while efficacy of chloroquine-pyrimethamine and chloroquine alone was almost comparable. A high proportion of relapse may be minimized, if 5-days radical treatment is given at appropriate time.

Plasmodium falciparum histidine rich protein-2 (PfHRP-2) based immunochromatographic test kit (ICT Malaria Pf) for the rapid diagnosis of P. falciparum malaria was evaluated at the clinic of Malaria Research Centre (Field Station), Goa. Of the 98 febrile patients screened, 22 were ICT positive for P. falciparum. Simultaneous microscopic examination of the blood smears of these ICT positive patients showed that 20 were positive for P. falciparum alone, whereas one had mix infection of both P. vivax and P. falciparum suggesting 100% sensitivity. Only one slide negative patient who had taken 600 mg chloroquine the previous day was positive in the ICT. Out of the remaining 76 blood smears, 41 showed P. vivax infection and none cross-reacted with P. falciparum HRP-2 antigen and were ICT negative except one mix infection case in which P. vivax and P. falciparum infections occurred concomitantly suggesting species specificity of 98.7%. The positive predictive value, negative predictive value and efficacy of the ICT were 95.4, 100 and 98.9% respectively. The band intensity of the ICT positive cases significantly correlated with P. falciparum parasitaemia (p < 0.01). The usefulness and the disadvantages of this diagnostic kit have been discussed in context of prevailing malaria situation in the country.

Longitudinal study taken up for one year in 10 different types of breeding habitats in Dindigul town, Tamil Nadu, revealed that out of 51,785 habitats 225 (0.43%) were found positive for Anopheles stephensi immatures. The overall positivity varied between 0.03 to 1.31% with peak density during July. The observed habitat-wise positivity was overhead tanks 0-7.07%; wells 0-1.69%; under ground tanks 0-2.26%; tappits 0-2.36%; outside tanks (permanent) 0-2.42%; outside tanks (temporary) 0-0.39%; inside tanks (permanent) 0-2.0%; inside tanks (temporary) 0-3.6%; barrels 0-1.32% and others 0-25.0%. In 16.0% habitats An. stephensi was found breeding with An. subpictus, Aedes aegypti, Ae. vittatus and Culex quinquefasciatus in different combinations. Overhead tanks were found to contribute maximum An. Stephensi breeding in this area.

Alterations in the levels of plasma and erythrocyte membrane lipids in fresh and repeated P. vivax malarial patients were studied. A significant fall in plasma cholesterol and phospholipids was observed in repeated malaria. The decrease was highly significant when the number of attacks were more than five (p < 0.0001). A significant increase in plasma triglycerides and non-esterified fatty acids were observed when the number of attacks was between 4-5 (p < 0.0001). Erythrocyte membrane cholesterol and phospholipids were increased in repeated malaria. The increase in erythrocyte membrane cholesterol and phospholipids, was significant in more than five attacks (p < 0.0001). The activities of LCAT and LPL were decreased significantly in repeated malaria, when the number of attacks were between 4-5 (p < 0.0001). It is suggested that repeated malarial attack alters the lipid metabolism and the changes are marked with increase in the number of malarial attacks.

A recently developed peptide ELISA method was used for monitoring the efficacy of malaria control programme in the tribal areas of Madhya Pradesh. Both crude Pf antigen and synthetic nonapeptide were used in ELISA for seroepidemiological studies. Both antigen responded equally well but the synthetic peptide had advantages of purity, defined characteristic and easy availability. Population of Mandla protected by vector control measures showed lower antibody titre and lower percentage positivity compared to the unprotected population of Jabalpur. A 0-5 yrs sentinel population from Haldwani almost seronegative has been taken as control.

Kerosene lamps containing one per cent neem oil were used for mosquito repellent action in a village near Delhi. The safety aspects of this personal protection method developed by Malaria Research Centre were evaluated by animal studies and clinical examination of population before and after exposure. Single application of neem oil (1%) did not produce skin irritation in rabbits and adverse effect on guinea pigs after exposure to aerosol. Clinical examination of 156 adults and 110 children did not reveal any major adverse effects after one year of exposure to 1% neem oil.

A study was undertaken to determine the level of chloroquine sensitivity in P. falciparum strains prevalent in a rural, tribal-belt of Bharuch district, Gujarat during 1992-93. Of the 32 cases for which the 7-day follow-up was completed, only in one RII level of resistance was noted, with the mean parasite clearance time in the remaining cases being 1.87 days. Thus, chloroquine continues to be effective in treatment on falciparum malaria in this area.

A feasibility study to identify mosquitogenic conditions in six study sites in and around Delhi (Bhalaswa lake, Nazafgarh drain, Seelampur lake, Sanjay lake, Okhla barrage and Hindon barrage) using Indian Remote Sensing Satellites was carried out. The water bodies with marshy areas, vegetation and human settlements were considered as environmental variables responsible for mosquitogenic conditions. Multidate IRS 1A and B, LISS-II satellite data were collected and analysed on Vax 11/780 computers. False colour composite (FCC) images were generated and land cover assessed using supervised classification based on ground truth training sets. Ground truth validation of satellite data was done on satellite pass dates. Concurrent monitoring of larval and adult mosquito density was performed by selecting sub-sites in each study site. The results indicate that mosquitogenic conditions can be identified (with limitation of resolution, i.e. 36.5 m) using FCC images and these images can be used as base maps of study sites. Characterization of study sites based on land cover was done from the view point of mosquitogenic conditions. Spatial changes in mosquito density vis-a-vis changes in environmental variables revealed positive correlation with water bodies and vegetation in some study sites.