Burden of sickle cell disease in tribal students in Maa-Baadi institutions in southern Rajasthan - A pilot study

Background & objectives: Sickle cell disease (SCD), an inherited disorder of erythrocytes, is highly prevalent in the tribal population of India. The tribal population of India is approximately 100 million and it is necessary to identify the magnitude of this problem. Furthermore, the prevalence of the disease is unknown among the five million tribal people of southern provinces of Rajasthan. In this study, we intended to determine the prevalence and characteristics of sickle cell disorder among the tribal inhabitants of southern Rajasthan. Methods: This cross-sectional study was conducted among the tribal students of the Maa-Baadis and hostels situated in the five tribal sub-plan districts of Rajasthan. Maa-Baadi centres are located in every village, whereas for every four to five villages, one hostel is allocated to accommodate the tribal students. The screening for SCD was done by solubility test and electrophoresis was used for confirmation. Results: A total of 36,752 tribal students were screened from 1,006 Maa-Baadi centres and 243 hostels. The prevalence of SCD among the tribal students was 5.8 per cent. The prevalence of heterozygous and homozygous conditions was 5.61 and 0.17 per cent, respectively. Among the five sub-plan districts, the highest prevalence was observed in Sirohi district (10.5%) followed by Banswara (7.42%), Udaipur (6.53%), Pratapgarh (5.51%) and Dungarpur (1.89%). Among the four major tribes belonging to these districts, the highest prevalence was recorded in Garasia tribes (13.81%). The history of leg ulcers and the mean pulse rate were significantly high in SCD individuals. Interpretation & conclusions: SCD is a significant problem among the tribes of southern Rajasthan, with the highest prevalence among the Garasia tribe. The present study recommends that a structured screening programme targeting the entire tribal population with appropriate counselling as well as providing treatment through the existing health system is the need of the hour.

In vitro assessment of drug resistance in Plasmodium falciparum in five States of India.

Background & objectives: In vitro assays are an important tool to assess baseline sensitivity and monitor the drug response of Plasmodium falciparum over time and place and, therefore, can provide background information for the development and evaluation of drug policies. This study was aimed at determining the in vitro sensitivity of P. falciparum isolates to antimalarials. Methods: The in vitro activity of 108 P. falciparum isolates obtained from five States of India was evaluated using WHO microtest (Mark III) to chloroquine, monodesethylamodiaquine, dihydroartesunate and mefloquine. Samples were collected from the States of Orissa, Jharkhand, Karnataka, Goa and Chhattisgarh from September 2007 to August 2009. In addition, representative samples from different States of India cryopreserved and culture adapted in the Malaria Parasite Bank of National Institute of Malaria Research, New Delhi, were also evaluated. Results: The proportion of isolates resistant to chloroquine and monodesethylamodiaquine was 44.4 and 25 per cent, respectively. Of the 27 isolates resistant to monodesethylamodiaquine, 16 (59.3%) were cross-resistant to chloroquine. No isolate showed resistance to dihydroartesunate and mefloquine. Isolates from Orissa showed the highest degree of resistance to chloroquine and amodiaquine followed by Jharkhand. Forty two isolates were genotyped for pfcrt T76K chloroquine resistant mutation; mutations were seen in 38 (90.47%) isolates. Interpretation & conclusions: The Indian P. falciparum isolates showed a high degree of resistance to chloroquine followed by monodesethylamodiaquine. No resistance was recorded to mefloquine and dihydroartesunate.

Retrospective study of chikungunya outbreak in urban areas of India.

Background & objectives: A retrospective study on chikungunya outbreak in India in five States viz. Delhi, Madhya Pradesh, Orissa, Maharashtra and Kerala was conducted in 2007-2008 to know the distribution and determinants of chikungunya fever outbreak in India. Methods: On the basis of high and low incidence of chikungunya fever, two districts from each State and two wards from the selected district were taken for random selection of 1000 households from 10 districts and 5 States. Semi-structured questionnaires were administered to individuals, patients, qualified health professionals and to stakeholders for collecting information. Results: The educational background and occupation of the respondents showed variations across the study States. Only in high incidence ward of Maharashtra, water storage period for 3-6 days and emptying, drying of water containers on weekly basis was noted. The study through knowledge, attitude, belief, practice (KABP) obtained individual's perception of chikungunya fever, its prevention and control. Patients’ expenditure on treatment was mainly recorded less than Rs 500 across study States. Health facility survey obtained an overview of the capacity of local health facilities. Stakeholders’ perception regarding chikungunya fever was also noted. Interpretation & Conclusions: The study revealed differences in awareness of chikungunya, cause of the disease, vector responsible, mode of transmission, biting time and elimination of breeding of mosquitoes statistically significant among high and low incidence wards of all the States. Expenditure on treatment was independent of economically active status and loss of man-days across all the States. Education and occupation did not have any relation with emptying/drying of water containers in high incidence wards. Strengthening of surveillance, information, education and communication (IEC) activities along with case management facilities may be provided by the State health department for prevention of chikungunya outbreaks in future. Stakeholders should be more involved in outbreak management and future planning.

Field evaluation of ZeroFly® - an insecticide incorporated plastic sheeting against malaria vectors & its impact on malaria transmission in tribal area of northern Orissa.

Background & objectives: Insecticide incorporated plastic sheeting is a new technology to control mosquitoes in emergency shelter places and also temporary habitations in different locations. Therefore, field studies were conducted to assess the efficacy of ZeroFly® plastic sheeting treated with deltamethrin on prevailing disease vectors Anopheles culicifacies and An. fluviatilis and its impact on malaria transmission in one of the highly endemic areas of Orissa. Methods: The study was conducted in Birkera block of Sundargarh district, Orissa state. The study area comprised 3 villages, which were randomized as ZeroFly plastic sheet, untreated plastic sheet and no sheet area. ZeroFly plastic sheets and untreated plastic sheets were fixed in study and control villages respectively covering all the rooms in each household. Longitudinal studies were conducted on the bioefficacy with the help of cone bioassays, monitoring of the mosquito density through hand catch, floor sheet and exit trap collections and fortnightly domiciliary active surveillance in all the study villages. Results: In ZeroFly plastic sheeting area, there was a significant reduction of 84.7 per cent in the entry rate of total mosquitoes in comparison to pre-intervention phase. There was 56.2 per cent immediate mortality in total mosquitoes in houses with ZeroFly sheeting. The overall feeding success rate of mosquitoes in the trial village was only 12.5 per cent in comparison to 49.7 and 51.1 per cent in villages with untreated plastic sheet and no sheet respectively. There was a significant reduction of 65.0 and 70.5 per cent in malaria incidence in ZeroFly plastic sheeting area as compared to untreated plastic sheet and no sheet area respectively. Interpretation & conclusions: Our study showed that introduction of ZeroFly plastic sheets in a community-based intervention programme is operationally feasible to contain malaria especially in the high transmission difficult areas.

Evaluation of Tribulus terrestris Linn (Zygophyllaceae) Acetone extract for Larvicidal and Repellence Activity against Mosquito Vectors.

Acetone extracts of leaves and seeds from the Tribulus terrestris (Zygophyllaceae) were tested against mature and immature different mosquito vectors under laboratory condition. The extract showed strong larvicidal, properties 100 per cent mortality in the 3rd-instar larvae was observed in the bioassays with An. culicifacies Giles species A, An. stephensi Liston , Culex quinquefasciatus Say and Aedes aegypti Linn ,against 200ppm of the leaf acetone extract and 100 ppm seed acetone extract. The LC values 50 of leaf acetone extract estimated for 3rd-instars An. culicifacies species A, An. stephensi, Cx. quinquefasciatus and Ae. aegypti after 24 hour of exposure were 117, 124, 168 and 185 ppm respectively. The LC values of seed 50 acetone extract estimated for 3rd-instars An. culicifacies species A, An. stephensi, Cx. quinquefasciatus and Ae. aegypti after 24 hour of exposure were 100, 72, 91 and 91 ppm respectively. It is confirmed from the LC values 50 that the seed acetone extract of T. terrestris is more effective compared to leaf extracts. A significant (P<0.004) higher concentration of acetone extract leaf was required to kill equal number of larvae i.e. against acetone extract of seed. The seed acetone extract showed strong repellent activity against adults mosquitoes. Per cent protection obtained against Anopheles culicifacies species A 100% repellency in 1h, 6h; Anopheles stephensi 100% repellency in 0h, 4h, 6h; and Culex quinquefasciatus 100% repellency in 0h, 2h, 4h, at 10% concentration respectively. Against Deet- 2.5% An. culicifacies Giles species A has shown 100% repellency in 1h,2h,6h , An. stephensi Liston 99% repellency in 4h , and Culex quinquefasciatus Say has shown 100% repellency in 1h,2h.