Desert Medicine Research Centre, Jodhpur

At Desert Medicine Research Centre, the major thrust areas of research have been on malaria, dengue, tuberculosis, silicosis, urolithiasis, hypertension, nutrition along with disease burden and environmental health problems. The important studies carried-out under the above disciplines are as follows:

A. COMMUNICABLE DISEASES

Dengue

Transovarial transmission (TOT) of Dengue virus in Aedes aegypti was reported for the first time from India by DMRC in 1996. Persistence of this phenomenon was studied across seven generations of mosquitoes. This study explained the maintenance mechanism of virus in nature during inter-epidemic periods. Vertical transmission of virus among tree hole breeder Aedes albopictus and possible occurrence of zoonotic cycle of dengue involving monkey has been propounded. Observations made have helped explaining the etiology of virus maintenance in nature during inter endemic period of disease.

Malaria

Epidemiology of malaria under desert conditions has been studied. A GIS based module for monitoring and forecasting malaria has been developed. Software to predict prospective magnitude of malaria through interaction of parasitized human population, mosquito vector density and population density of cattle and human bait has been developed. It is under verification through longitudinal studies. Research undertaken will lead to the development of epidemiological module of prevention and control of malaria in desert.

Guinea worm Disease (Dracunculiasis)

Behavioural epidemiology of Cyclops, the vector of Guinea worm disease, dracunculiasis was studied in desert ecology of Rajasthan leading to development of useful tool for eradication of the disease. As Member, National Commission for Guinea Worm Eradication Certification team, eradication of Guinea worm disease from the country was certified.

Tuberculosis

1. Utility of BCG test in exclusion of TB in sputum negative suspects of PTB

A considerable proportion of cases treated for pulmonary tuberculosis are sputum negative. They are given anti-tuberculous medication on the premise that tuberculosis could not be excluded in them. BCG Test is nearly100% sensitive except in cases with immunosuppression. It is not specific test as it is also sensitive to MTB. Lack of specificity keeps this test useless in diagnosing of TB. Utility of its high negative predictive value in excluding TB was assessed. Results showed that BCG test was positive in all sputum positive cases indicating 100% sensitivity and 16.3% of sputum negative suspects of pulmonary tuberculosis were negative to BCG test. The test can be used for exclusion of tuberculosis in sputum negative suspects of PTB.

2. Blood glutaraldehyde gelification test for diagnosis of PTB

Blood Glutaraldehyde Gelification Time (BGT) has been known to be reduced in cases of pulmonary tuberculosis. The exact cause of the same is not known but higher fibrinogen level and higher titer of non-specific immunoglobulins in cases of pulmonary tuberculosis may be responsible for it. Blood samples stored at 2-8 °C and the tests carried out at 22 °C showed that BGT test was >80% sensitive and >90% specific for diagnosis of PTB. It is a simple, easy, inexpensive, rapid and reliable blood test for diagnosis of pulmonary tuberculosis.

3. Drug resistance

Sputum samples of symptomatic quarry workers and cases of pulmonary tuberculosis attending District Tuberculosis Clinic, Jodhpur were studied for Drug resistance in PTB using LJ medium for culture of Mycobacterium tuberculosis. Primary drug resistance to isoniazid was observed to be 16.7%, rifampicin 6.7%, streptomycin in 16.7% and ethambutol 6.7% samples. Multidrug Resistance (MDR) as defined by WHO (resistance to isoniazid and rifampicin with or without resistance to other drugs) in cases without any history of previous antituberculous treatment was found in 3.3% cases. Acquired MDR was found in 38.2% cases. The study highlighted the importance of an adequate and effective drug regimen.

Leptospirosis

A study covering 276 individuals of both the sexes (184 males and 92 females) were subjected to Lepto-Dipstick test, including 54 tests on paired samples. 6 individuals (2.2%) were found to be positive for Lepto-Dipstick test. Patients comprised of 5 male and 1 female from 15-44 years age group. The study has provided basic information on the occurrence of leptospirosis in Rajasthan

B. NON-COMMUNICABLE DISEASES

Urolithiasis

A hospital based study revealed that the prevalence of upper urinary tract stones was higher in Jaipur, Jodhpur, Bikaner, Ajmer and Pali districts whereas Barmer, Jalore, Nagaur and Jaisalmer districts had higher prevalence of lower urinary tract stones. Cases of upper urinary calculus were more common in urban area and those of lower urinary calculus in rural area. Mixed stones were common, followed by calcium oxalate stones. Recurrence rate of calculi was found to be 22.0%. 16.0% cases had family history. Patients from urban areas consumed more pulses, green vegetables and tomatoes, whereas, those from rural areas consumed onions, milk, buttermilk and curd.

Hypertension

A study on prevalence of known hypertension revealed that the prevalence of hypertension was 17.9 % in one village compared to 1.5% in another village. The estimated prevalence of hypertension on the basis of rule of halves would be 35.8% and 3.0% respectively. From the study emerged the need to undertake the studies on associated risk factors of hypertension and administration of life style interventions on the basis of identified risk factors.

In another study the prevalence of hypertension in non-brine salt workers was found to be 12.2% and in brine 7.0% workers. Use of protective devices i.e. facemasks and spectacles exhibited their positive effect on systolic and diastolic blood pressures up to fourth day and helped in reducing the quantum of complaints.

Silicosis

Chest radiographs of 9.9% stone quarry workers showed opacities suggestive of silicosis, more than 15% showed opacities suggestive of tuberculosis and sputum of 3.6% showed acid fast bacilli (AFB) indicative of active tuberculous disease. Spirometery of these workers revealed restriction in 24.9%, obstruction in 48.3% and mixed abnormality in 13.7%. Among ex-workers 33.3% showed opacities suggestive of silicosis. Follow up of workers revealed that most of them lived10 years less than their fellow villagers who never worked in quarries. Respirable dust in these quarries was more than 19.1 mg/m3 air with free silica contents more than 80%. Dry mechanical drilling of rocks was the most important source of air born dust in these quarries.

The study showed that traditionally used Dry Drilling Unit consisting of tractor and compressor, could be converted into Wet Drilling Unit at a cost of Rs. 4000. Director General of Mines Safety, Govt. of India recommended this method to Government of Rajasthan for implementation of wet drilling in sand stone quarries of Rajasthan.

Porphyria

Rural community of Kumhars of Bikaner district of Western Rajasthan screened for Acute Intermittent Porphyria (AIP) using Watson-Schwartz Test in 1237 individuals distributed among 20 randomly selected villages of Bikaner district gave the prevalence of AIP as 1.16%. (CI=0.012±0.0005). The cases exhibited varied symptoms. Overall preponderance was in favour of females (2:1). Majority (38.9%) of cases belonged to 20-29 years of age. Average age of manifestation was 24.5±4.8 years. Prevalence of disease as such warrants the need for generating of awareness in this community for early detection and better management of the disease.

Indicators of health assessment

A cross sectional study and based on sample of households in the identified clusters from twenty six districts revealed that all selected villages had access to safe drinking water source but their domestic water storing method was not safe. 78.6% of households had access to safe drinking water. 5.1% of households were having sanitary latrines. Salt samples of 53.7% of households were found positive for iodine. Proportion of school going boys (89.4%) was higher than girls (71.6%) among 5-11 years age group. Period prevalence of diarrhoea (during last 3 months) in under five age children was 12.3%. ORS advice rate among those seeking treatment was 47.5%. Only 24.1% children were completely immunized. 13.2% of parents of 12-23 months old children were used family planning methods. Two or more ante-natal checkups were received by 43.2% mothers and 35.3% deliveries were attended by the trained health professionals. Only 16.2% of mothers started breast feeding within 12 hours of the birth of their children. The exclusive breast feeding was observed in 4.4% and inclusive water feeding in 4.6% children, whereas, prelacteal breast feeding was observed in 91.0% children. The overall prevalence of malnutrition was 14.0% in 0-23 months old children and the prevalence among females was higher (15.3%) than males (12.8%). All indicators except safe drinking water indicated poor health profile in all the 26 districts of the state.

C. VECTOR BIONOMICS

Thirty four species belonging to 10 genera viz. Anopheles (annularis, barbirostris, culicifacies, fluviatilis, pulcherrimus, stephensi & subpictus), Culex (gellidus, vishnui, pseudovishnui, quinquefasciatus, bitaeniorhynchus, tritaeniorhynchus, raptor & malayi), Aedes (aegypti, albopictus, vittatus & w-albus), Phlebotomus (papatasi & sergenti), Sergentomyia (babu, clydei, baghdadis, bailyi & punjabensis) Hyalomma (anatolicum, dromadarii & kumari), Rhipicephalus (sanguinius, haemophysaloids & turanicus), Ornithodorus (moubata), Pediculus (capatalis & corporis) and Xenopsylla (cheopis), were recorded from both desert and non-desert districts. This fauna includes some of the proven vectors of malaria, dengue, JE, filariasis, cutaneous leishmaniasis, tick borne fevers and plague. Cx. pseudovishnui, and Cx. tritaeniorhynchus have been reported for the first time from this region. An. fluviatilis, Cx. Gelidus and Ae. vittatus were reported only from non-desert parts, whereas, An. culicifacies, barbirostris, pulcherrimus, Cx. tritaeniorhynchs and Cx. pseudovishnui only from desert command area and Cx. malayi from non-command desert. The occurrence of Cx. pseudovishnui, and Cx. tritaeniorhynchus, both proven vectors of Japanese Encephalitis, in desert and their breeding in ponds, pools and seasonal wells is not only a unique finding but also a matter of epidemiological importance.

Bio-ecology of mosquito immatures

In desert areas, three important habitats viz. pitchers, cemented tanks and tanka (under-ground water storage tanks peculiar to desert areas) supported mosquito breeding throughout the year, whereas, habitats like ponds, temporary water collections, seasonal rivers or canals, supported only during monsoon/post-monsoon. In non-desert areas, habitats like cemented tanks, wells/step-wells, ponds and slow-flowing streams were found supporting mosquito breeding during monsoon, post-monsoon and winter months. Active breeding of An. annularis, An. culicifacies and An. subpictus was observed only during monsoon and post-monsoon months, whereas, of An. stephensi and Cx. quinquefasciatus throughout the year. Information on different aspects of anopheline breeding are helpful for planning mosquito control strategies.

Insecticide resistance

Six insecticides, DDT, dieldrin, malathion, fenitrothion, propoxur and permethrin were tested against all important mosquito species prevalent in the area. All prevalent vector species have developed resistance to both the organochlorine compounds. They exhibited either resistance or intermediate resistance to malathion. Against fenitrothion all species were susceptible, except Cx. quinquefasciatus, which showed intermediate resistance. All culicines were resistant against propoxur, whereas, the anophelines were either susceptible or partial resistant. All species were found susceptible to permethrin exept Cx. Quinquefasciatus showing intermediate resistance. Study is indicative of management of inseticide resistance for effective vector control.

Insecticidal efficacy of indigenous plant extracts

Solanum xanthocarpum a plant species was identified having insecticidal properties against mosquito larvae. Studies revealed that fruit extract was most potential larvicide against vectors of malaria and dengue. Studies are suggestive of chemical characterization of active principal responsible for the larvicidal properties for formulation of commercial product.

Mosquito larvicidal microbial agents

Experiments on the effect of temperature on efficacy of Bacillus thuringiensis var. israelensis (Bti) and Bacillus sphaericus (Bs) indicated that effectiveness of Bs increased with the increase of temperature against Cx. quinquefasciatus. Bti also gave similar results when tested against An. stephensi. The quality of water also affected the efficacy of Bs when evaluated against Cx. quinquefasciatus. The results suggest that water quality and temperature need to be considered at the time of deciding dose of Bacillus sphaericus for field application.

Phlebotomine sand flies

Sandflies were represented by seven species viz. P.papatasi, P. sergenti, S. punjabensis, S. babu babu, S. clydei, S. bailyi and S. baghdadis collected from indoor habitats. Maximum density of sand flies was observed during the monsoon and post-monsoon season, followed by spring, summer and winter seasons. Precipitin tests carried out on the host preference of phlebotomine sand flies revealed that out of 126 blood smears prepared from P. papatasi 88.8% were human, 7.3% bovine and 3.9% were mixed for both bovine and human. Sergentomyia babu preferred human blood (75%) and S. punjabensis, besides human blood, also exhibited mixed feeding.

P. papatasi was resistant to DDT, dieldrin & propoxur and susceptible to malathion, fenitrothion and permethrin in district Bikaner. In rural areas resistance was more pronounced to DDT and dieldrin compared to urban areas. S. punjabensis was, however, found susceptible to DDT and dieldrin with LC50 values 1.45% and 0.032% respectively. P. papatasi however showed resistance to only DDT in Barmer district.

D. EPIDEMIOLOGICAL INVESTIGATIONS

Epidemic of respiratory symptoms following fogging

An epidemic of acute respiratory disease occurred following fogging of insecticide dichlorvos (DDVP) using diesel as solvent in the fog generator in Jaipur. Incidence of cases was 58.9% among people present on roads at the time of fogging as compared to those inside the rooms (5.4%) and away from the locality (1.8%) [Relative risk=32.7 and Attributable risk=96.9%]. The investigations indicated strong association between fogging and occurrence of symptoms. Signs and symptoms of organo-phosphorus poisoning were absent. Defective functioning of the fogging machine leading to generation of an unusual heavy fog was diagnosed to be responsible for irritation of eyes and respiratory tract of exposed individuals.

Mysterious respiratory disease

Deaths due to respiratory disease like tuberculosis, among villagers of Harirampura of Karauli district, Rajasthan engaged in stone quarrying were investigated. Investigations revealed that silicosis was widely prevalent in the area. History of 25 deaths of quarry workers since 1995, was obtained. Their age at the time of death was less than 35 years in 48% cases. All of them had worked in deep tunnel type of sandstone mines. They had suffered from some chronic respiratory disease, but any prescription, X-ray or report of laboratory investigation was not available. Exact nature of the deceased could therefore not be verified. However, among forty-four villagers having history of working in tunnel type of sandstone mines, their X-ray chest showed opacities suggestive of silicosis in 68.2% cases. Seventeen (12.3%) of 138 sputum samples collected were found positive for AFB. It could, therefore, be concluded that occupational silicosis together with tuberculosis was endemic and responsible for reported deaths in the village.

Epidemic of convulsions and vomiting

Six families of Gond tribes in Amarpur village about 25 km from Jabalpur reported cases of convulsions and vomiting. Infants and lactating mothers escaped the disease. Persons from neighbouring villages who came to attend funeral of a victim and took food with these families, also had attacks of similar symptoms on their return. The dog also had convulsions after consuming the vomitus. A girl from these families was married in another village. She took some flour from these families to her in laws house and her father in law and brother in law also got attacks of similar symptoms. All these indicated that it was an epidemic caused by contaminated food. Absence of fever and neck rigidity in all cases ruled out possibility of any, infection or meningitis. Based on the above observations and distribution of cases, it seemed that wheat floor was contaminated by some insecticide.

Laboratory investigations of samples of eatables confirmed contamination of food with endosulfan.

E. NUTRITION

Drought surveys

Rapid Drought Survey in Sikar, Nagaur, Jodhpur, Jaisalmer Barmer and Jalore districts of Rajasthan in 1987 showed widely prevalent incidence of vitamin A deficiency in Barmer, Jodhpur, Jalore and Jaisalmer district. In Barmer 50% of children and 50% adults were showing evidences of vitaminosis A. Clinical cases of PEM in all the six districts were ranging from 3 to 17%. Grade III malnutrition was prevalent to an extent of 17.3%. Calorie intakes were significantly lower in all the age groups in all the districts.

Augmentation of the ongoing relief measures ensuring the supply of minimum calories to all the age groups as well as supply of adequate doses of Vitamin A, Iron and Folic Acid were recommended.

Prevalences of Vitamin A and B complex deficiencies during drought of 2003 were found to be highly improved compared to 1987. However, the prevalence of protein calorie malnutrition was higher (32.3 %) in comparison to 1987 survey (17.8%). Supplimentation programme of Vitamin A and Iron of the state government appeared to function well in reducing vitamin A & B complex deficiency to a large extant. Inadequate consumption of daily food, deficient in calories and proteins, appeared to be the cause of protein calorie malnutrition needing attention.

Calorie Supplementation programme

Calorie supplementation programme was undertaken in villages of Chouhtan tehsil of Barmer district. People who were nutritionally poor i.e. with some clinical signs, low weights and having poor nutrition judged by dietary habits, vulnerable group including pre-school and school age children, lactating and pregnant women were included in the programme. After Six months the significant positive changes in the weight and height status and nutritional status among the subjects were recorded.

Vitamin A Supplementation

Drought survey indicated severe Vitamin A deficiency in Barmer district. Vitamin A and IFA were supplementation given to the children and women. Impact assessment showed that there was a significant improvement in night blind ness, xerophthalmia, conjunctival xerosis and Bitot spots in the population. Vitamin A deficiency was reduced from 40% to 12 %.

Nutritional status of the preschool and school age children

Studies were carried for assessment of nutritional status along with the morbidity pattern of the preschool and school age children in desert areas. School age children were found suffering from Protein calorie malnutrition (21.3%), Vitamin A and B complex deficiencies (3 to 4%). 22.5 per cent children were found to be anemic. Diet of children showed deficit in Calorie (30.2 % boys & 23.4 % girls). Protein intake met the allowances recommended by the ICMR. Nearly 50 per cent school age children were found suffering from long and short-term malnutrition. In preschool children high percentage (34.4 %) of short term malnutrition was observed, which was higher in girls (18.1 %) than boys (13.5 %) in <2 years of age. Thereafter the reverse trend was observed i.e. higher in boys (20.2 %) than girls (16.1 %). Average daily consumption of pulses, vegetables, tubers, fats and sugars were less as compared to RDA, ICMR. Percent prevalence of Anemia, Vit. A & B Complex deficiencies along with skin , eyes and respiratory morbidities were significantly higher in desert area (11.8, 4.4, 4.6, 10.7, 8.9, 3.5 % respectively) as compared to non-desert area. The study highlighted need for intervention programme and developing local nutritional packages.

Infant feeding practices and Maternal beliefs regarding diet during common childhood illnesses

Majority of the mothers (88%) discarded colostrums. Mean duration of breast feeding was 26 months. In children aged 6-9 months, only 23 percent of infants received timely complementary feeding. During childhood illnesses majority of mothers restrict food to their children. It is the mothers perception and cultural beliefs which determine the foods to be delivered to the child during illness. Results are helpful for planning community based educational intervention programs for study area.

Nutrition and Health Status of Tribals

Studies were carried-out in Barmer, Dungarpur and Sirohi districts. Grade III malnutrition in preschool children was 13.5%. Prevalence of Vit. A deficiency in pre-school children was 5.0%. Clinical PEM cases were around 3 to 5% in the pre-schools children. Prevalence of dental fluorosis was very high in Sirohi (>50%). Results highlighted the importance of interventional measures for tribals.

Textile Industry Workers

A large number of workers are presently involved in various activities of textile industry such as dying, printing and bleaching and are being exposed to hazards of textile industry. Workers complained of aches, fever, abdominal pain and respiratory problem (8-20%) comparatively higher then general population.

Chronic energy malnutrition and anemia were found to be 43.5 & 66.0% respectively. Protein calorie malnutrition, Vitamin A, Vitamin B-complex and Vitamin C deficiencies were also significant. Workers diet deficient in calories (20.5%) and Vitamin-A (42.9%), but rich in proteins in comparison to RDA of ICMR appeared to be responsible for nutrition related morbidities among textile workers.

F. OPIUM ADDICTION

Socio-cultural factors associated with opium consumption
pattern

A house to house survey was carried out covering 1200 opium/doda consumers and 1450 non consumers from three selected districts of Jaisalmer, Barmer and Bikaner. Statistical analysis showed that the mean age of consumption was 40.4 ± 8.28 years, 38.2 ± 9.44 years and 39.3 ± 6.45 years in Jaisalmer, Barmer and Bikaner respectively. Prevalence rates were 8.4, 7.9 and 6.9 respectively. Majority of the individuals surveyed were illiterates (82%). Average age of alcohol consumption was 36.4, 38.7 and 34.6 years. Major caste groups of opium/doda addicts were Rajputs (52.3%), Jats/Choudharies (23.1%) and Vishnois (14.7%). Major reasons for consumption were hard field work, medication or time pass. Average daily consumption was 11.8 gms of opium and 210 gms of doda. Average duration of consumption was more than 10 years in all the three districts. Recurrence rates calculated were 2.8% in Jaisalmer, 3.6% in Barmer and 4.8% in Bikaner districts.

Opium Consumption and effect on the Fertility in Women

The study was conducted in 12 villages of two desert districts viz., Barmer and Bikaner where the consumption of opium is very high. Indirect effect of opium consumption was studied among the addicts over a duration of time, which affects the fertility of their wives. Data was collected on 312 randomly selected couples in the child bearing age, whose husbands were addicts. Analysis showed majority of the consumers (40.4%) were in the age group of 35-40 years. Around 50.6% of husbands have started the consumption of opium at an early age. Fecundability estimates were calculated by discrete probability model and the estimates were increasing with the age. Estimates of average fecundability showed an increasing trend with parity. Study suggests that the probably the opium addiction adversely effects fertility.

Associated Risk Factors of Tobacco smoking among opium consumers

Tobacco smokers and opium consumers were separated and analysed for associated risk factors. Relative risk (RR) of the opium consumers was 1.68 and that of smokers 2.44. Smokers have more risk of chronic diseases than opium consumers. Risk factors like chronic cough, stomach pain, chest pain, Coronary Heart Diseases (CHD) were common among opium consumers who were chronic smokers. Duration of consumption of both the substances was highly correlated with diseases r = 0.8. Association of smoking tobacco and opium addiction has significant correlation with chronic diseases (P<0.05).

De-addiction of opium

Adult males, in western Rajasthan, were found to traditionally consume crude opium with cultural acceptance. Prevalence of opium addicts was found to be 7.1%. Abrupt withdrawal technique is being used in local hospitals and camps for de-addiction of addicts. Gradual withdrawal method of de-addiction of opium addicts was found to be less severe and more acceptable.

Increased Susceptibility to Tuberculosis

Prevalence of opium addiction among tuberculous patients from rural desert was significantly high in comparison to general population (X2 = 11.6, p > 0.001). The addiction always preceded the pulmonary tuberculosis, which confirmed that difference was not due to use of opium by tuberculous patients to suppress cough. A case control analysis of matched pairs showed significant association between opium addiction and pulmonary tuberculosis (Odd's ratio = 2.61 and attributable risk = 0.099). Results were consistent in different age and ethnic groups.