Research

Primary focus    :  Mosquito borne diseases, Drug abuse and HIV/AIDS, Trematode infections, Haemoglobinopathies

Secondary focus :  Cancers (Nasopharynx, Oesophagus, Stomach), Hypertension and Coronary heart disease, Medicinal plants of NE India

Mosquito borne diseases: Malaria, Japanese encephalitis (JE) and filariasis are the most important mosquito borne diseases prevalent in the north-eastern states. North-eastern region of India though contributes to about 3.7% Indian population yet shares 8-10% of all malaria cases and 13-15% malaria deaths reported in the country putting severe burden on the economy of the region. Predominantly Plasmodium falciparum malaria (~80%), highly endemic in hills, foothills and forest areas of NE India, is chiefly maintained by Anopheles dirus complex and An. minimus complex mosquitoes. Japanese encephalitis is endemic in Assam (Dibrugarh, North Lakhimpur, Sibsagar, Jorhat and Sonitpur highly endemic districts) with annual average morbidity of about 300 cases and ~ 41% case fatality rate. Bancroftian filariasis disease, transmitted by Culex quinquefasciatus mosquitoes, is overwhelmingly concentrated in tea garden populations of Assam with an estimate of 0.36 million microfilaraemia carriers and 90,000 clinical cases.

Drug abuse and HIV/AIDS: North-eastern region of India, being in close proximity to the Golden Triangle, faces illegal drug trafficking and drug abuse problem in an acute manner. There is a gradient with higher prevalence of drug abuse in international bordering  north-eastern states, thus, Manipur leading the region with approximately 11 drug users per 1000 population. Injecting the drug is the most common form of drug abuse in Manipur, Mizoram and Nagaland. The National AIDS Control Organization reports a seropositivity rate of 7.7 per thousand in sero-surveillance of high risk groups and general population estimates of 1.7 per thousand in India. Transmission of HIV in north-eastern region is mainly associated with the injecting drug abuse. Opium, alcohol and tobacco are other commonly abused substances in NE region.

Trematode infections: Food borne trematode infections and schistosomal dermatitis are public health concerns in north-eastern region of India. Due to the peculiar food habits of different ethnic groups in north-east India, especially eating raw/poorly cooked crabs, pulmonary paragonimiasis is widely prevalent in this region. Caused by the Paragonimus, the lung fluke, pulmonary paragonimiasis disease mimics the symptoms of pulmonary tuberculosis causing a diagnostic dilemma to the treating physicians. At least 7 trematodes have been found to cause human infections in this region. Recently non-human schistosomes like Schistosoma spindale, S. nasale and occulate schistosomes have been incriminated as the causative organisms of paddy field dermatitis, a serious occupational disease putting millions of agricultural labourers at risk, in Assam.

Haemoglobinopathies: As per an estimate there might be about 45 million carriers and about 15,000 infants are born each year with haemoglobinopathies in India. The carrier frequency of haemoglobinopathies varies from 3 to 17% while cumulative gene frequency of three most predominant abnormal haemoglobinopathies i.e. sickle cell, Hb D and Hb E has been estimated to be 5.4% in different population groups of India. In north-east India, especially Assam, high prevalence of (20-60%) of Hb E, the most common haemoglobin variant among the local inhabitants belonging to Mongoloid ethnic stock, and Hb S among the immigrant tea garden labour population has been reported.

Cancers: In north-eastern region of India, cancer of nasopharynx (NPC) has been found to be highest in the country i.e. 1% of total carcinoma cases as compared to all India average of 0.6%. Within the region, 55% of total NPC cases are reported from Nagaland followed by Manipur (22.1%). Cancer of oesophagus, the highest reported (11.2% of all cancers in NE region) and cancer of stomach are prevalent cancers in Assam and Mizoram respectively.

Hypertension and Coronary Heart Disease: All India prevalence pattern shows that in urban population prevalence of hypertension is 6.5% while in rural population it is 3.6%; prevalence of CHD in urban and rural populations is 5.7% and 2.1% respectively. An uneven prevalence of hypertension has been reported in various population groups in north-east India. While Mizos have less prevalence of hypertension, it is very high in tea garden population in Assam and is in between in indigenous Assamese population.

Medicinal plants of NE India: North-east India is very rich in floral diversity and is one among the three hot spots of bio-diversity in India. Many ethnic groups of North-eastern region practice their traditional system of medicine, mostly relying on indigenous plants for curing various ailments. The medicinal properties of locally available plants need authentic documentation and scientific verification.

Outstanding Contributions

(i) Cancers

  • Risk factors analysis of nasopharyngeal carcinoma in Nagaland, oesophageal cancer in Assam and stomach cancer in Mizoram 

(ii) Malaria

  • Development of a module for malaria control in forest based camps
  • Detection of multi drug resistant falciparum malaria
  • First detection of a focus of Plasmodium ovale in north-east India
  • Detection of very good antimalarial property in an indigenous plant.

(iii) Japanese encephalitis

  • Development of an early warning system for the occurrence of Japanese encephalitis in Assam

(iv) Filariaisis

  • Development of a module for control of filariaisis in tea garden set up

(v) Trematode infections

  • Detection of foci of paragonimiasis in NE India and development of a ELISA kit for identification of Paragonimiasis
  • Development of rat model for Paragonimiasis
  • Demonstration of dermatitis in paddy field workers due to non human schistosomes in Assam
  • Detection of new foci of food borne infections like Heterophyesis, Clonorchiasis and Faciola hepatica  in north-east India

(vi) Entomology

  • Discovered, described and named three new mosquito species viz. Uranotaenia dibrugarhensis, Verrallina assamensis & Armigeges mahantai
  • Seven new country records of mosquitoes reported viz. Aedes ostentatio, Armigeres joloensis, Culex peytoni, Cx. variatus, Cx. alienus, Cx. quadripalpis, Tripteroides tarsalis

(vii) Hypertension & CHD

  • Finding of differential in hypertension prevalence in different ethnic groups of NE India

State specific research activities carried out

(i) Assam

Malaria epidemiology, transmission and control, antimalarial drug resistance, malaria vector(s) biology and vector control; Epidemiology of filariasis and control in tea garden set up, filariasis vector bionomics; Epidemiology, distribution and control of Japanese encephalitis, JE vector(s) bionomics and incrimination, development of Early warning system for JE ;  Prevalence of West Nile virus activity; Mosquito fauna survey ; Diarrhoeal diseases and their etiology; Extent and correlates of substance abuse, sero-surveillance and diagnosis of HIV, mapping and size estimation of injecting drug users; Etiology of endemic goiter and role of environmental goiterogens, prevalence of  iodine deficiency disorders, outreach and evaluation of iodized salt, iron deficiency anemia and work efficiency, anthropometric studies in tea garden children, nutritional studies on unconventional food items, sub-clinical vitamin A dificiency; Epidemiology and risk factors analysis of oesophageal cancer, population based cancer registry ; Immunization coverage and status of neo-natal deaths in tea gardens, fertility and socio-economic factors of rural women ; Schistosomes causing farmers dermatitis , food borne trematodes;  Status of haemoglobinopathies, effect of maternal haemoglobinopathy on pregnancy outcome, community control of thalassaemia syndrome; Status of hypertension and coronary heart disease in Assamese and tea garden populations; Disease burden of leptosporiasis ; Molecular epidemiology of methycillin resistant Staphylococcus aureaus; Molecular epidemiology of tuberculosis; Epidemiology of sporotrichosis; Risk factors analysis of non-communicable diseases; Health consequences of domestic violence ; Multi site monitoring of human influenza virus ;

(ii) Meghalaya

Malaria vector(s) biology, operationalization of insecticide treated mosquito nets; Mosquito fauna surveys; Extent and correlates of Substance abuse, sero-surveillance and diagnosis of HIV, mapping and size estimation of injecting drug users; Prevalence of iodine deficiency disorders ; Pulmonary paragonimiasis ; Health consequences of domestic violence; Molecular epidemiology of tuberculosis

(iii) Arunachal Pradesh

Malaria epidemiology, transmission studies and  control, antimalarial drug resistance especially in Indo-Myanmar border areas, malaria vector(s) biology and vector control ; operationalization of insecticide treated mosquito nets; Mosquito fauna surveys; Extent and correlates of substance abuse, sero-surveillance and diagnosis of HIV; Pulmonary paragonimiasis; Molecular epidemiology of tuberculosis ; Immunization coverage

(iv) Mizoram

Malaria vector(s) biology, operationalization of insecticide treated mosquito nets; Mosquito fauna surveys; Extent and correlates of Substance abuse ; mapping and size estimation of injecting drug users, studies on HIV/AIDS and drug abuse;  Population based cancer registry; risk factors analysis of stomach cancer, mutagenecity of tuibur; immunization coverage; Reproductive health among adolescent and adult girl students; Status of hypertension and coronary heart disease; Integrated disease surveillance programme; Etiology of endemic goiter and role of environmental goiterogens

(v) Nagaland
 
Malaria vector(s) biology, operationalization of insecticide treated mosquito nets; mosquito fauna surveys, prevalence of dengue and its vectors; Extent and correlates of Substance abuse, mapping and size estimation of injecting drug users, integrated biological and behavioural assessment of HIV/AIDS, studies on HIV/AIDS and drug abuse; Risk factors analysis of nasopharyngeal cancer, mutagenecity of food items ; Dietary survey of CRPF jawans; Molecular epidemiology of tuberculosis

(vi) Manipur

Malaria vector(s) biology, mosquito fauna surveys; Mapping and size estimation of injecting drug users, integrated biological and behavioural assessment of HIV/AIDS ; population based cancer registry

(vii) Tripura

Malaria vector(s) biology, mosquito fauna surveys; Immunization coverage; Haemoglobinopathies and viral markers among primitive tribes of Tripura; Cancer registry

(viii) Sikkim

Population based cancer registry; Morbidity surveillance; Food borne trematodes ; Molecular epidemiology of tuberculosis; Health consequences of domestic violence

Additional information