Impact of DDT spraying on malaria transmission in Bareilly District, Uttar Pradesh, India.

BACKGROUND & OBJECTIVES: Impact of indoor residual spraying of DDT on malaria transmission and vector density was evaluated in six villages of Shergarh PHC, Bareilly district, Uttar Pradesh under the operational condition of National Vector Borne Disease Control Programme (NVBDCP) from July 2001 to March 2002 (one transmission season only). METHODS: Two rounds of DDT (50% WDP) spraying @ 1 g/m2 were done both in the experimental and control villages by the state health authorities. The spraying in experimental villages was supervised by Malaria Research Centre (MRC) whereas the district health authorities supervised the operation in control villages. Mass blood surveys were made three times--before the first round, in between the first and second rounds and after the second round of spraying. The blood smears were examined by the trained microscopists of MRC, Haldwani. From the above examinations epidemiological indicators such as slide positivity rate (SPR), slide falciparum rate (SFR) and infant parasite rate (IPR) were calculated. All malaria positive cases were given radical treatment as per NVBDCP schedule. Entomological parameters such as per man hour mosquito density, parity rate, gonotrophic condition and adult susceptibility status of Anopheles culicifacies to diagnostic dosages of DDT (4%) were monitored as per the standard techniques. RESULTS: A total of 988.5 kg of DDT was consumed during two rounds of spray. The house coverage varied from 87 to 95.3%. Parasitological evaluation revealed significant reduction in malaria cases (p < 0.0005) and infant parasite rate declined from 2.9 to 0%. Entomological observations revealed considerable reduction in the density of malaria vector An. culicifacies despite of its 21.4% mortality against DDT test papers. INTERPRETATION & CONCLUSION: The overall results of the study revealed that DDT is still a viable insecticide in indoor residual spraying owing to its effectivity in well supervised spray operation and high excito-repellency factor.

Efficacy of a new formulation of Bacillus thuringiensis var israelensis (Bti) in laboratory and field conditions of Kumaun foothills of Uttaranchal, India.

Efficacy of a new Bti formulation was tested in the laboratory and small scale field trials against mosquito larvae were carried out from March to June, 2001 in different breeding habitats of Kumaun foothill region of Nainital and Udham Singh Nagar districts, Uttaranchal state, India. Laboratory tests revealed increased efficacy against Culex quinquefasciatus (LC50 = 0.035 mg/L) followed by Aedes aegypti (LC50 = 0.0628 mg/L), An. culicifacies sp A (LC50 = 0.184mg/L) and An. stephensi (LC50 - 0.2216mg/L). Results of field trials revealed 100% mortality of mosquito larvae after treatment with Bti @ 0.5 gm/m2 surface area. The impact was similar on different mosquito species breeding in different habitats. However, repeated treatments were required due to reappearance of larvae in the breeding habitats within a week. No side effects of Bti was observed during field trial on non- target organisms (NTOs). Environmental disturbances and man made problems affected the spray impact of Bti.

Malaria outbreak in Bhojpur PHC of district Moradabad, Uttar Pradesh, India.

Based on the reports of 18 fever related deaths in Bhojpur Primary Health Centre (PHC) of Moradabad District (UP), a study was undertaken during September and October, 2000 to explore the possibility of outbreak of malaria in the area and the reasons of the outbreak. The slide positivity rate (SPR) and slide falciparum rate (SFR) in active fever surveys were found to be 84.7% and 82.2% respectively. Among children the average enlarged spleen and spleen rate were 1.9 and 27.4 per cent respectively. The mortality rate of Anopheles culicifacies in DDT, Malathion and Deltamethrin was 42.5, 86.7 and cent per cent respectively. The results of the study revealed that the outbreak was of malaria with predominance of Plasmodium falciparum causing several deaths in the affected villages. The investigation revealed that there was disruption of surveillance and supervision of malaria activities.

Assessment of left ventricular function in chronic severe anaemia. An echocardiographic study.

Left ventricle (LV) performance was assessed by echocardiography (2-D and M-mode) in 30 patients with chronic severe anaemia and an equal number of age and sex matched healthy controls. Patients with anaemia were divided into two groups: those with tachycardia (pulse rate more than 100 per min) and those without. LV performance indices computed were LV ejection fraction (LVEF), % fractional shortening (FS), cardiac index (CI) and stroke volume index (SVI). In patients of anaemia with tachycardia, LVEF was 48.6 +/- 8.41 (mean +/- SEM) vs 71.6 +/- 4.96 among controls. Percentage FS was 19.93 +/- 4.21 vs 36.0 +/- 4.5, CI 5.46 +/- 1.2 vs 3.1 +/- 0.78 l/min/m2, and stroke index 48.6 +/- 12.2 vs 41.5 +/- 10.7 ml/beat/m2. In patients without tachycardia, LVEF was 55.1 +/- 8.86, percentage FS 23.6 +/- 5.42, CI 2.87 +/- 0.526 and stroke index 41.34 +/- 12.1. These findings suggest that LV performance was depressed in both groups of patients with anaemia but LV function was better in patients without tachycardia.

Comparative value of glutamic oxaloacetic transaminase and lactic dehydrogenase enzyme pattern in serum and cerebrospinal fluid in acute cerebrovascular accidents.

A study of glutamic oxaloacetic transaminase (GOT) and lactic dehydrogenase (LDH) enzymes in serum and cerebrospinal fluid (CSF) was carried out on 30 cases of acute cerebrovascular accident (CVA) to determine their role in precise diagnosis and prognosis of the cases. The CSF GOT and LDH activities were well correlated with the severity, mortality and peak and proper timing in relation to infarct, same is about serum GOT. A characteristic rise of GOT and LDH was observed in cerebral haemorrhage especially in fatal cases. However, in cerebral thrombosis and embolism specially in non-fatal cases, the enzyme change was not so marked. GOT and LDH enzyme pattern in CSF and serum may, therefore, serve as an early, relatively easy and widely available tool for differential diagnosis and prognosis of cases of acute CVA.