Evaluation of PermaNet 2.0 mosquito bednets against mosquitoes, including Anopheles minimus s.l., in India

Wash resistance and field bioefficacy of PermaNet 2.0 nets, long lasting insecticidal nets, against mosquitoes were evaluated in Assam, northeastern India. After repeated hand washings at 12-day intervals a decline in the mosquito killing ability of PermaNet nets was noted (trend chi2 38.9, p < 0.0001), yet these nets retained good insecticidal efficacy for up to 15 wash cycles, producing a 72.5% mean mortality of An. minimus 24 hours after a 3-minute exposure in World Health Organization cones after 15 washings. Significantly fewer (p < 0.001) mosquitoes were captured in self-baited landing collections in houses equipped with PermaNet nets than in houses using untreated nets in the case of culicines (p < 0.001) but not with anophelines, including An. minimus. The use of PermaNet nets resulted in noticeably fewer bites from Culex pseudovishnui (68.5%) and Cx. quinquefasciatus (70%). Blood-feeding inhibition of mosquitoes in deliberately torn PermaNet nets was seen, indicating a protective effect for those sleeping under these nets. No serious adverse effects of the PermaNet nets were reported by users.

Risk of hepatitis C infection among injection drug users in Mizoram, India

BACKGROUND & OBJECTIVE

Prevalence of injection drug users (IDUs) is high in the northeastern region of India. This coupled with unsafe injecting practices as well as practice of tattooing in remote tribal areas call for baseline data on the prevalence of parentally transmitted viral diseases. In the present study we aimed to measure the risk behaviours and seroprevalence of hepatitis C virus (HCV) antibodies amongst IDUs of Mizoram, a State of the northeast India.

METHODS

A cross-sectional study was conducted in 2004-2005 amongst IDUs (including female sex workers) who had injected in the past six months and were unaware of their HCV/HIV status. They were recruited from various drop-in centers from Aizawl, Mizoram, and screened for anti-HCV antibodies using 3(rd) generation HCV EIA and recombinant immunoblot assay (RIBA).

RESULTS

The prevalence of HCV antibodies was 71.2 per cent among the active IDUs. On univariate analysis increasing duration of injection, syringe sharing and heroin (diacetylmorphine) injectors were at a significantly higher risk of acquiring HCV antibodies (P<0.001). On multivariate analysis, HCV antibody prevalence showed a strong association with the type of drugs injected (P=0.001), frequency of injecting (P=0.013), multiplicity of drugs abused (P=0.004), and needle syringe sharing (P=0.003).

INTERPRETATION & CONCLUSION

Unsafe injecting practices were found to be associated with a higher risk of acquiring hepatitis C infection. Our findings showed that syringe and needle exchange programme alone was not sufficient as a preventive strategy for control of hepatitis C infection among IDUs of Aizawl.

Community practices of using bed nets & acceptance & prospects of scaling up insecticide treated nets in north-east India

BACKGROUND & OBJECTIVE

The National Vector Borne Disease Control Programme (NVBDCP), India has been promoting and scaling up the use of insecticide-treated nets (ITNs) in the tribal dominated malarious areas of north-east India. But, information on sleeping habits, bed net ownership and use practices, and feedback of communities in ITN--targeted areas is needed for formulating a strategic framework for upscaling the coverage of ITNs. We carried out a community-based cross-sectional survey in select areas of Nagaland and Mizoram (where ITNs were introduced) along with Assam (where ITNs were not introduced) to know the response of community.

METHODS

Following large scale introduction of ITNs during 2001-2002 in the north-eastern States of Nagaland and Mizoram by NVBDCP, India, a cross-sectional community-based survey was undertaken in April-May, 2003 covering 435 households of Nagaland and 464 households in Mizoram, using a structured questionnaire, to assess the demographic variables relevant to bed net use, bed net washing practices and acceptability of ITNs etc., for upscaling the coverage of ITNs in the surveyed communities. A total of 448 households in 8 villages in a non-ITN PHC area of Assam were served as the control area.

RESULTS

The average bet net usage per family (2.01 to 2.65). Bed net use was mostly seasonal in Nagaland where a majority (65.1-78.7%) used bed nets only during summers and monsoon as compared to the year round use in Mizoram (83.5%) and Assam (78.9%). Frequent washing of nets was most common in Assamese communities with 77 per cent households washing their nets at least once in a month. More than two third users favoured use of ITNs over the conventional indoor residual spray of DDT for malaria control.

INTERPRETATION & CONCLUSION

ITNs are widely acceptable in the user communities and a demand for ITNs is evident in the non-user communities of north-east India. Approach of treating community owned nets through an efficient service delivery mechanism will be a viable option for upscaling the ITN coverage.

Detection & molecular confirmation of a focus of Plasmodium malariae in Arunachal Pradesh, India

BACKGROUND & OBJECTIVE

During a malaria epidemiological study in Arunachal Pradesh, Plasmodium malariae like human malaria parasites were seen in blood smears from fever cases. The study was undertaken to detect the presence of P. malariae and to confirm its identity through DNA based polymerase chain reaction approach.

METHODS

Fever survey was carried out in 22 villages in Indo-Myanmar bordering district of Lohit, Arunachal Pradesh in 2005. Morphologically suspected P. malariae cases were confirmed using nested PCR based on 18S small subunit ribosomal DNA gene sequence.

RESULTS

Screening of 1,995 fever cases resulted in 9 probable cases of P. malariae based on morphological identification in Chakma tribe people residing in 2 villages. Nested PCR confirmed the identity of all probable cases of P. malariae by producing diagnostic band of 144 bp. PCR method was able to detect mixed infection of P. malariae with P. vivax and with P. falciparum.

INTERPRETATION & CONCLUSION

P. malariae may have been present in Arunachal Pradesh but most probably is being misdiagnosed due to its close resemblance with P. vivax, especially in ring forms. Estimation of actual case load of P. malariae in north-east India is, therefore, important with accurate species identification using molecular methods.

Ocular thelaziasis in Assam: a report of two cases

Small, white, thread-like, motile worms were recovered from the conjunctival sac of a 13-year-old girl and a 50-year-old woman from Dibrugarh district, Assam, India. They were identified as thelazia species. These two cases have been reported due to their rarity in India and elsewhere.

Urban rural differences in prevalence of self-reported diabetes in India--the WHO-ICMR Indian NCD risk factor surveillance

Recent reports show strikingly high prevalence of diabetes among urban Asian Indians; however, there are very few studies comparing urban, peri-urban and rural prevalence rates of diabetes and their risk factors at the national level. This study is a part of the national non-communicable diseases (NCD) risk factor surveillance conducted in different geographical locations (North, South, East, West/Central) in India between April 2003 and March 2005. A total of 44,523 individuals (age: 15-64 years) inclusive of 15,239 from urban, 15,760 from peri-urban/slum and 13,524 from rural areas were recruited. Major risk factors were studied using modified WHO STEPS approach. Diabetes was diagnosed based on self-reported diabetes diagnosed by a physician. The lowest prevalence of self-reported diabetes was recorded in rural (3.1%) followed by peri-urban/slum (3.2%) and the highest in urban areas (7.3%, odds ratio (OR) for urban areas: 2.48, 95% confidence interval (CI): 2.21-2.79, p<0.001). Urban residents with abdominal obesity and sedentary activity had the highest prevalence of self-reported diabetes (11.3%) while rural residents without abdominal obesity performing vigorous activity had the lowest prevalence (0.7%). In conclusion, this nation-wide NCD risk factor surveillance study shows that the prevalence of self-reported diabetes is higher in urban, intermediate in peri-urban and lowest in rural areas. Urban residence, abdominal obesity and physical inactivity are the risk factors associated with diabetes in this study.

Circulating genotypes of hepatitis B virus in Arunachal Pradesh

BACKGROUND & OBJECTIVE

There is a paucity of information on distribution of hepatitis B genotypes from northeastern part of India. Arunachal Pradesh, one of the northeastern State of India bordering Bhutan, China and Myanmar, reported abnormally high numbers of hepatitis B surface antigen (HBsAg) positive cases in one of its districts during January-June 2005. We conducted this study in the subsequent months (August-December 2005) to know the prevalent genotypes by a rapid and specific method based on type-specific primers in Upper Dibang valley of Arunachal Pradesh.

METHODS

A total of 438 randomly selected individual were screened for HBsAg positivity. Of the 93 HBsAg positive individuals, 36 HBsAg and HBV DNA positive samples were processed for HBV genotyping using type-specific primer based nested PCR (TSP-PCR). Representative samples were retested with RFLP-PCR based genotyping and nucleotide sequencing.

RESULTS

Of the 36 samples, 29 (80.1%) could be genotyped by the TSP-PCR based method used. The predominant genotype was genotype A (41.6%) followed by genotypes C (27.8%) and D (11.1%). Seven isolates (19.9%) could not be genotyped by this method.

INTERPRETATION & CONCLUSION

The presence of genotype C in this part of the country needs attention as genotype C takes a more aggressive disease course. Also, detection of genotype C in this isolated community bordering Tibet suggests viral gene flow from Tibet or other South-east Asian countries where genotype C of HBV is predominant.

Hyperendemic foci of hepatitis B infection in Arunachal Pradesh, India

AIM

To study the prevalence of hepatitis B virus (HBV) infection among an isolated tribe of Northeast India that migrated long back from Tibet.

METHODS AND MATERIALS

Randomly selected 438 subjects from Idu Mishmi tribe of Arunachal Pradesh were screened for hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), hepatitis B surface antibody (anti-HBs), envelope antigen (HBeAg) using ELISA kits.

RESULTS

The point prevalence of HBsAg was found to be 21.2% (93/438). Anti-HBc prevalence was 92.3% (193/209). Anti-HBs above 10 IU/ml were detected in 48% (96/200). Prevalence of HBeAg was higher (42.1%, 16/38) in children (less than 15 years) compared to adolescent and adults (32.7%, 18/55). History of hepatitis was significantly associated with positive HBsAg status (p < 0.000).

CONCLUSION

Hepatitis B virus infection is hyperendemic among Idu Mishmi tribe of Arunachal Pradesh, India. Though, the route of transmission could not be ascertained, but the high HBV infection (78.6%) among less than 5 yrs and the finding of 58.4% of HBsAg positive mothers bearing HBsAg positive child indicates possibility of vertical transmission in this setting.

Pleuropulmonary paragonimiasis due to Paragonimus heterotremus: molecular diagnosis, prevalence of infection and clinicoradiological features in an endemic area of northeastern India

In the northeastern region of India, paragonimiasis is emerging as an important public health problem. However, until now the identity of the species causing human infection has been uncertain and there has been little information on the prevalence and clinicoradiological features of infection in the community. Parasitological and immunological surveys revealed that paragonimiasis was hyperendemic in parts of Arunachal Pradesh. Egg positivity in the sputum was 20.9% and 4.1% in children (age </=15 years) and adults (age >15 years), respectively. Antibody positivity against excretory-secretory antigen of the adult worm in children and adults was 51.7% and 18.7%, respectively. Chronic cough (97.2%) and haemoptysis (83.3%) were common respiratory symptoms among egg-positive cases. Chest radiography (n=68) images from egg-positive cases showed that air space consolidation (75%), cavitary lesions (14.7%) and mediastinal adenopathy (11.8%) were very frequent. Less frequent findings were nodular lesions, bronchiectasis, mediastinal adenopathy, pleural thickening and pleural effusion. DNA extracted from eggs from the sputum of patients from Arunachal Pradesh was sequenced. Analyses of the second internal transcribed spacer (ITS2) of nuclear rDNA revealed that the species responsible is Paragonimus heterotremus.

Onychomycosis by Scytalidium dimidiatum in green tea leaf pluckers: report of two cases

Two cases of onychomycosis in green tea leaf pluckers caused by Scytalidium dimidiatum, a dematiaceous non-dermatophytic mold has been described. Onychomycosis caused by Scytalidium dimidiatum is clinically indistinguishable from that caused by dermatophytes and responds poorly to antifungals. The clinical presentations in the cases were of distal subungual type with associated melanonychia involving thumbnails. These cases have unique importance, because besides disfigurement, this has adversely affected the livelihood of the patient and poor response to antifungal dissuaded them from treatment compliance. To the best of our knowledge, this is the first report of onychomycosis caused by Scytalidium dimidiatum in green tea leaf pluckers.

Nutritional status of adolescents among tea garden workers

OBJECTIVE

The study was conducted to evaluate growth and nutritional status using weight and height based indicators among tea garden adolescent boys and girls of Assam aged between 10-18 years.

METHODS

A cross sectional study was carried out in the tea gardens of Dibrugarh district of Assam through house to house visit. Households were selected through two stage sampling design to reach out the adolescents. Height and weight were measured using standard procedures. Body mass index (BMI) was computed from height and weight. Height-for-age below 3rd percentile values of NCHS reference was classified as stunting. BMI-for-age below 5th percentile values of WHO recommended reference was classified as thinness.

RESULTS

Total numbers of 605 adolescents (boys-291, girls-314) participated in the study. School enrollment rate was only 59.2%. Prevalence of stunting was 47.4% and 51.9% among boys and girls respectively relative to NCHS reference, which reduced to almost 30% while Indian reference data was used. Prevalence of thinness was higher among boys (59.5%) than girls (41.3%) counterparts. Mean BMI among girls was higher at all ages than boys.

CONCLUSION

Almost half of the adolescents were stunted and most of them were thin. Problem of overweight was seen in less than 0.5% of adolescents. Factors typical to underdeveloped society seems to contribute to the moderate to high prevalence of undernutrition among adolescents working in tea gardens.

Addition of three species of Topomyia (Diptera: Culicidae) to the mosquito fauna of Northeastern India

Topomyia (Topomyia) hirtusa, Topomyia (Topomyia) bifurcata, and Topomyia (Suaymyia) cristata are recorded for the first time in India from the northeastern state of Arunachal Pradesh.

Study of health problems and nutritional status of tea garden population of Assam

BACKGROUND

Assam is the highest tea producer state in the country. There is scarcity of reliable information on health and nutritional status among tea garden population of Assam to enable initiating public health response to their health needs.

AIMS

To describe health problems and nutritional status among tea garden population of Assam.

SETTINGS AND DESIGN

Community-based cross-sectional survey in eight randomly selected tea gardens of Dibrugarh district of Assam.

MATERIALS AND METHODS

Socio-demographic and behavioral characteristics of participants were recorded. Health problems and nutritional status were assessed through medical examination, evaluation of medical records, anthropometry and laboratory investigations.

STATISTICAL ANALYSIS

Percentage prevalence; Chi-square test was applied wherever applicable.

RESULTS

Out of 4,016 participants, 1,863 were male and 2,153 were female. They were mostly illiterate and nearly 52.9% (1,197 of 2,264) of adults were manual workers in the garden. Alcohol and oral tobacco use were common. Prevalence of underweight among children was 59.9% (357 of 596) and thinness among adults was 69.9% (1,213 of 1,735). Anemia was widespread. Worm infection (65.4%, 217 of 332); skin problems; respiratory infections, including tuberculosis; filariasis were present in a significant way. Children suffered more in various diseases. Major noncommunicable diseases like hypertension, stroke were emerging in the community and were associated with modifiable risk factors like alcohol and tobacco use.

CONCLUSION

Health status of the population can be ameliorated through better hygienic practices, environmental sanitation, creating health awareness, nutritional intervention and overall improvement of socioeconomic conditions of the population.

Molecular characterization and species identification of the Anopheles dirus and An. minimus complexes in north-east India using r-DNA ITS-2

The sibling species composition of the Anopheles minimus and Anopheles dirus complexes is poorly known in the highly malarious north-eastern region of India where these two vector taxa are accountable for most of the malaria transmission among 30.7 million inhabitants. Prevalent members of these two complexes in this part of India were identified using sequences for the second internal transcribed spacer (ITS2) of ribosomal DNA. Anopheles baimaii (species D) of the An. dirus complex and An. minimus s.s. (species A) of the An. minimus complex were detected in Arunachal Pradesh, Assam, Meghalaya and Nagaland states. No intraspecific variation was observed in the ITS2 sequence (479bp) of An. baimaii whereas a single substitution was detected in the ITS2 sequence (372bp) of An. minimus from Nagaland state.

Characterization of ITS2 rDNA of Anopheles philippinensis and Anopheles nivipes (Diptera: Culicidae) from north-east India

Anopheles (Cellia) philippinensis Ludlow and Anopheles (Cellia) nivipes (Theobald) are two closely related, morphologically very similar, mosquito species in the Annularis group, which play a supportive role in malaria transmission in north-east India. We amplified and performed sequence analysis for the internal transcribed spacer 2 (ITS2) locus of ribosomal DNA (rDNA) gene of morphologically confirmed specimens of these two species from the states of Assam and Nagaland. An. philippinensis and An. nivipes shared 85.2% sequence similarity and no intra-species variation was found in the nucleotide sequences of the two species. Overall, sequence data of the ITS2 marker revealed that both these species from north-east India differed by as much as have been reported from specimens of eastern Thailand.

Extended spectrum beta lactamase producing gram negative bacilli in a tertiary referral hospital of Assam--experience with two methods

Extended Spectrum Beta Lactamases (ESBL) are enzymes produced in some gram negative bacilli that mediate resistance to extended spectrum cephalosporins. 683 clinical isolates of Escherisia coli and Klebsiella pneumoniae were studied for their capacity to produce ESBL. Isolates showing resistance to at least two of the third generation cephalosporins were studied for ESBL production by Jarlier technique and combination disc methods. Out of the 457 E. Coli and 226 Klebsiella pneumoniae isolated in Assam Medical College, 29.76% and 53.1% were resistant to two cephalosporins of which 29.41% and 29.16% strains showed production of ESBL. However, 6 (4.41%) and 16 (13.34%) strains additionally showed production of ESBL when tested with combination disc method. Though the Jarlier technique is popular, for detection of ESBL, yet false negative results warrants for alternative method. In the absence of molecular detection methods in routine clinical microbiology laboratory, combination disc method appears to be a better option.

Health problems and disability of elderly individuals in two population groups from same geographical location

OBJECTIVE

To compare morbidity, disability (ADL-IADL disability) along with behavioral and biological correlates of diseases and disability of two elderly population groups (tea garden workers and urban dwellers) living in same geographical location.

METHODS

Two hundred and ninety three and 230 elderly from urban setting and tea garden respectively aged > 60 years were included in the study. Subjects were physical examined and activity of daily living instrumental activity of daily living (ADL-IADL) was assessed. Diagnosis of diseases was made on the basis of clinical evaluation, diagnosis and/or treatment of diseases done earlier elsewhere, available investigation reports, and electrocardiography. Hypertension was defined according to JNC-VI classification. BMI (weight/height2) was calculated. Logistic regression analysis was performed to see the impact of important background characteristics on non-communicable diseases (NCD) and disability.

RESULTS

Hypertension (urban--68% and tea garden--81.4%), musculoskeletal diseases (urban--62.5% and tea garden--67.5%), COPD and other respiratory problems (urban--30.4% and tea garden--32.2%), cataract (urban 40.3% and tea garden--33%), gastro-intestinal problems (urban--13% and tea garden--6.5%) were more commonly observed health problems among community dwellings elderly across both the groups. However in contrast to urban group, serious NCDs like Ischaemic Heart Disease (IHD), diabetes were yet to emerge as health problems among tea garden dwellers. Infectious morbidities, undernutrition and disability (ADL-IADL disability) were more pronounced among tea garden dwellers. Utilization of health service by tea garden elderly was very low in comparison to the urban elderly. Both tea garden men and women had very high rates of risk factors like use of non-smoked tobacco and consumption of alcohol. On the other hand, smoking and obesity was more common in urban group. Most morbidities and disabilities were associated with identifiable risk factors, such as obesity, tobacco (smoked and non-smoked) and alcohol consumption. Educational status was also found to be an important determinant of diseases and disability of elderly population. Age showed a J-shaped relationship with disability and morbidity. Sex difference in health status was also detected.

CONCLUSION

This study highlights the physical dimension of health problems of elderly individuals. Social circumstances and health risk behaviours play important role in the variation of health and functional status between the two groups. Life-style modification is warranted to prevent onset of chronic diseases. To improve quality of life, rectification of poor health status through affordable health service for disease screening and better management of illness, nutritional improvement and greater health awareness are necessary particularly among low socio-economic group. Low-cost intervention like cataract surgery could make a difference in the quality of life of elderly Indian.

Tobacco and alcohol use among the youth of the agricultural tea industry in Assam, India

A cross-sectional study was conducted to assess tobacco use (both smoking and non-smoked tobacco) and alcohol use among tea garden youths of Assam, India during the period 2002-2003. A total of 650 tea plantation youth age 15-24 years (255 males, 395 females) from eight randomly selected tea plantations, Dibrugarh District, Assam, were interviewed to collect information on alcohol and tobacco use using a pre-designed, pre-tested questionnaire. Nearly 59% of the respondents had no formal education. Fifty-eight percent of the youth used at least one substance and 27.4% were concurrent users of both alcohol and tobacco. The smoking rate was only 2.2% (4.7% in males, 0.5% in females). However, 52.5% of the study population used non-smoked tobacco (56.9% males, 49.6% females). The prevalence of alcohol consumption was 32.2% (43.9% males, 24.6% females). A higher rate of alcohol and tobacco use was found among the respondents who had no formal education or were school dropouts. A higher rate of alcohol and tobacco use were seen among respondents in whom both parents were illiterate. Working as a manual worker in the tea industry is significantly associated (p<0.01) with higher rates of alcohol and tobacco use. We recommend a vigorous campaign against tobacco and alcohol use among tea plantation youth to reduce the health risks associated with the use of these two substances.

Correlates of alcohol consumption and tobacco use among tea industry workers of Assam

An epidemiological study on alcohol and tobacco (smoking and nonsmoked tobacco) use was carried out in tea garden population of Assam, one of the largest agroindustries of India. A total sample of 2,264 individuals (male, 1,033; female, 1,231) aged 15 years and older was interviewed in 2002-2003 to collect information about alcohol and tobacco use using a predesigned and pretested questionnaire. Age-adjusted prevalence of alcohol consumption was 59.2% (male, 69.3%; female, 54%). Smoking was more common among males (13.2%) than females (2%). However, use of nonsmoked tobacco was almost as popular among female (71.9%) as among males (75.3%). More than half of the respondents (54.7%) were multiple users of alcohol and tobacco. Prevalence of alcohol consumption, nonsmoked tobacco use, and smoking among the young age group (15-24 years) was 32.2%, 52.5%, and 2.2%, respectively. Prevalence of smoking increased with age, and more than a quarter of males above 54 years were smokers. Similar age trends in the prevalence of alcohol and nonsmoked tobacco was not observed. Sociodemographic correlates, like education, occupation, and marital status, emerged as important predictors of substance uses irrespective of sex. Association of income with substance use was weak in this study, perhaps due to homogeneity of income level. Users of alcohol and tobacco were mostly illiterate, manual workers, and widows/widowers. However, smokers were more common among sedentary worker. Not withstanding the limitations of the study, the findings of the study are useful for planning interventional strategy to control alcohol and tobacco use for better health outcome.

Malaria transmission risk by the mosquito Anopheles baimaii (formerly known as An. dirus species D) at different hours of the night in North-east India

The risk of acquiring malaria transmitted by Anopheles baimaii Sallum & Peyton, 2005, formerly known as An. dirus species D (Sallum et al., 2005) (Diptera: Culicidae), at different hours of the night in a forest-fringed village of Assam, North-east India was assessed through all-night mosquito landing catches during 1995-2000. An estimated overall mean biting rate of 36.1 bites/person/night (95% CI = 26.2-45.8), a sporozoite rate of 1.9% (95% CI = 1.1-2.9%) and a parous rate of 58.7% (95% CI = 55.3-62.0%) were recorded. Parous and sporozoite-positive females tended to be caught mainly before midnight. The effective entomological inoculation rate was the highest (0.249 positive bites/person/night) from 21.00 to 24.00 hours, suggesting that the second quartile of the night is the most risky period for malaria transmission by An. baimaii. Considering that approximately 21% of mean inoculations take place before 21.00 hours, it appears that there is a need for appropriate protective measures during the pre-bed time period to supplement the impact of insecticide-treated nets against An. baimaii in north-east India.

Potential of Anopheles philippinensis-nivipes complex mosquitoes as malaria vector in north-east India

Anopheles philippinensis-nivipes complex mosquitoes, captured in outdoor human landing catches and light traps in human dwellings from four different sites in Assam state and adjoining areas, were examined (n=1670) for the presence of circumsporozoite antigen (CSA) through enzyme linked immunosorbent assays (ELISA), using species specific capture monoclonal antibodies, of Plasmodium falciparum and two Plasmodium vivax polymorphs (Pv 210 and VK 247). In ELISA, 28 pools were found positive for CSA that accounted for minimum sporozoite rate of 1.7% (95% CI 1.11-2.41). Twenty five percent (7/28) of the positive pools were reactive for P. falciparum and between the two polymorphs of P. vivax, VK 247 was predominant with 77% (20/26) of all P. vivax positive pools. Results were suggestive of most likely involvement of Anopheles philippinensis-nivipes complex mosquitoes in malaria transmission in north-east India.

Biodiversity of mosquitoes in Manipur State and their medical significance

Entomological studies conducted during monsoon and post-monsoon season in Manipur State revealed the presence of fifty-five species of mosquitoes under ten genera. Out of the seventeen Anopheles species recorded, Anopheles aconitus, An. dirus and An. nivipes were recorded for the first time from the state. The present study has confirmed the existence of An. dirus, the major malaria vector in the Northeast from a selected area of the state. Among Culicines, four species viz., Aedes nigrostriatus, Malaya genurostris, Aediomyia catasticta and Toxorhynchites splendens which were not reported earlier from this state have been recorded in the present study. With the addition of these seven species of mosquitoes to the earlier record of mosquitoes so far reported from Manipur, the mosquito fauna swells up to one hundred and eleven including the major vectors of malaria of the Northeast and the potential vectors of Japanese encephalitis and dengue virus transmission in India.

A cholera epidemic in a rural area of northeast India

Sporadic cases of acute diarrhoea with high morbidity occur commonly in rural areas of northeast India, throughout the year. At times they take epidemic form and one such outbreak occurred with attack and case fatality rates of 11.6% and 0.8%, respectively, in October 2002, in a remote locality of Assam. Vibrio cholerae O1 El Tor Ogawa was isolated in 63% of hospitalized acute diarrhoea patients. Ineffective antibacterial treatment, poor hygiene practices and bad peridomestic sanitation were the factors associated with the persistence and spread of the pathogen, leading to the outbreak of cholera, resistant to commonly-used antimicrobials.

Evaluation of chloroquine (CQ) and sulphadoxine/pyrimethamine (SP) therapy in uncomplicated falciparum malaria in Indo-Myanmar border areas

Chloroquine (CQ) and sulphadoxine/pyrimethamine (SP) are two first-line antimalarials used under the existing Indian National Drug Policy in the north-eastern region of India bordering several countries including Myanmar. Although widespread resistance to antimalarials in Plasmodium falciparum has been reported from western Myanmar, information from the Indian side of the border is scarce. We studied the therapeutic response to CQ and SP at four sites in Changlang and Lohit, two administrative districts of Arunachal Pradesh bordering Myanmar. We monitored uncomplicated falciparum malaria patients after treatment with standard regimens of CQ and SP for 28 days following the revised in-vivo protocol of the World Health Organization. A total of 236 patients, 95 in the CQ group and 141 in the SP group, participated. We recorded 23.8% early treatment failures to CQ and 14.1% to SP; late clinical failures of 14.3 and 12.6%; late parasitological failures of 10.7 and 8.1% and adequate clinical and parasitological responses of 51.2 and 65.2%, respectively. The significantly different treatment failure rates seen in Chowkham (furthest from Indo-Myanmar border) and Jairampur/Nampong (nearest to Indo-Myanmar border) for chloroquine (Cox proportion hazard ratio 9.1, P<0.0001) and SP (Cox proportion hazard ratio 7.35, P=0.001) denote a non-response gradient to the two antimalarials extending from the international border. The gradient is probably indicative of the direction of movement of the drug-resistant P. falciparum parasite. The utility of chloroquine as the first-line drug under the present National Drug Policy in these areas needs reconsideration.

Development of enzyme-linked immunosorbent assay for serodiagnosis of human paragonimiasis

BACKGROUND & OBJECTIVE

Although human paragonimiasis is known to occur in Manipur and Arunachal Pradesh, there is no indigenous immunodiagnostic test available in India. Sputum examination for detection of eggs is less sensitive method for diagnosis of paragonimiasis and unfortunately, the eggs are not always present in the sputum of infected individuals. Due to overlapping clinical manifestations and similarities between X-ray picture in pulmonary paragonimiasis and pulmonary tuberculosis, chances of diagnostic confusion can increase. Therefore, the objective of this study was to develop an ELISA test indigenously for diagnosis of paragonimiasis.

METHODS

Somatic (S) and excretory-secretory (ES) antigens of adult trematodes belonging to genus Paragonimus were prepared. Serum samples were collected from 22 confirmed patients of paragonimiasis and from five groups of negative controls. The cut-off points for both types of antigens were calculated using receiver operating characteristic (ROC) curve analysis. The sensitivity, specificity, predictive values and efficiency of the ELISA tests were also calculated.

RESULTS

IgG-ELISA test using either S or ES antigens were 100 per cent sensitive yet the utility of S antigen for diagnosis of paragonimiasis seemed to be less reliable because of low specificity (91.3%). On the other hand, ES antigen was more reliable with 100 per cent specificity as no false positive cases were recorded.

INTERPRETATION & CONCLUSION

ES antigen can be effectively used for screening large populations for paragonimiasis. In areas where both paragonimiasis and tuberculosis are endemic, suspected subjects should be screened for both the diseases because of chance of mistaken diagnosis. Correct diagnosis will avoid unnecessary costly treatment.

Perceptions of unmarried young women regarding family size, sexually transmitted diseases at residential regional institutes in northeastern India

This study sought to assess the knowledge and attitudes of young unmarried women regarding family size and sexually transmitted diseases, including HIV, in three residential regional institutes of northeastern India. The data is expected to help in reinforcing various methods of Information, Education and Communication (IEC) implementation. A representative sample of 574 female students, 16-25 years of age, were interviewed by a pretested questionnaire to assess their knowledge of the determinants of family size and sexually transmitted diseases. Of the participants, 48.43% stated that the suitable age for marriage is > 18 years old for women. More than half the respondents stated that the interval between child birth should be 3-5 years. Most of the respondents (96.17%) were of the opinion that both parents are responsible for determining the number of children. Knowledge of STDs and HIV was found in 91.8% and 74.04% of respondents, respectively.

Taxonomical observations on Anopheles philippinensis/nivipes group mosquitoes in north-east India

To examine the distribution pattern of Anopheles philippinensis and An. nivipes, mosquitoes belonging to An. philippinensis/nivipes group were collected from five sites in north-east Indian state of Assam and its adjoining areas and identified. Presence of both An. philippinensis and An. nivipes, with predominance of the latter taxon, was recorded with conformity on the basis of pupal paddle characteristics. Based on adult wing characters, 91.4% specimens were identified as An. philippinensis and 8.6% as An. nivipes with gradually increasing proportion of An. nivipes in westwardly direction. An. philippinensis/ nivipes was noted to be mid night biter, mainly exophagic and exclusively exophilic. Of the two species, An. philippinensis appears to be mostly anthropophilic and available in broken forest areas whereas An. nivipes seems to be mostly zoophilic and generally found in ecotone zones in plains areas.

Hypertension in the native rural population of Assam

BACKGROUND

Recent studies have reported an increasing prevalence of hypertension in India. However, there are few epidemiological data with regard to the occurrence of hypertension in the native population of Assam.

METHODS

Three thousand one hundred and eighty individuals (1441 men and 1739 women), > or =30 years of age and from 25 villages of 5 districts in Assam were selected by the stratified random sampling method. They were interviewed and their blood pressure measured along with other anthropometric variables. Hypertension was defined according to the Sixth Report of the Joint National Committee on prevention, detection, evaluation and treatment of high blood pressure (JNC-VI).

RESULTS

The overall prevalence of hypertension was 33.3%. Among the patients with hypertension, 21.6% were aware of their illness. The determinants of hypertension were age, intake of extra salt in the diet, body mass index and waist-hip ratio (derived by multiple logistic regression analysis with backward elimination of non-significant factors). Multivariate analysis showed that females had a higher risk of hypertension than males.

CONCLUSION

The prevalence of hypertension in the native population of Assam is high. Implementation of an effective awareness programme with lifestyle modifications is necessary to control the cardiovascular disease burden in this population.

A focus of lymphatic filariasis in a tea garden worker community of central Assam

A survey for lymphatic filariasis was conducted among tea garden workers of central Assam. Of the 656 night blood samples examined, 31 were found positive for Wuchereria bancrofti parasite (microfilaria rate 4.7%). Microfilaria rate was higher in male (7.3%) than females (2.1%). Culex quinquefasciatus was incriminated as vector mosquito.

Cure and reinfection patterns of geohelminthic infections after treatment in communities inhabiting the tropical rainforest of Assam, India

Mass de-worming targeted at socio-economically poor communities can be considered as an option for communities living in the tropical forests of Assam who do not have access to safe drinking water and proper sanitation, and consequently have a higher risk of suffering from geohelminthic infection and associated morbidity. A random sample of 265 subjects was included in this study (134 males and 131 females). The chemotherapeutic regimen followed was a single dose of albendazole 400 mg. Stools samples were collected in 10% formol-saline for detection of infection before treatment. Post-treatment stool samples were collected 10 to 14 days after treatment to determine the cure rate. Stool samples were again collected 3 to 6 months post-treatment to study the rate of reinfection. Multiple logistic regression was used to find possible associations between age, sex and treatment failure. The chi-square test was used wherever appropriate. The cure rates for Ascaris lumbricoides, Trichuris trichiura and hookworms were 70.8%, 68.7% and 93.0%, respectively. Logistic regression revealed that age was associated with treatment failure in A. lumbricoides infection. Re-infection rates after 3 months of successful treatment were 19.6% for A. lumbricoides, 30.9% for T. trichiura and 11.3% for hookworms. Six months post-treatment, the prevalence of re-infection was highest with T. trichiura (43.6%); followed by A. lumbricoides (35.3%). The rate of reinfection with hookworms was lower (11.3%) six months post-treatment. The rates of re-infection with A. lumbricoides and T. trichiura was higher in children below 15 years of age, compared with adults. Hookworm reinfection was higher in the adult age group (15 to 39 years). The rates of new infection in previously uninfected subjects were lower compared with the rates for re-infection.

Japanese encephalitis in Assam, northeast India

Japanese encephalitis is one of the major public health problems in Assam, northeast India. We aimed to elucidated the clinical and epidemiological profile of the disease during several outbreaks in Assam in 3 consecutive years. Cerebro-spinal fluid and or serum samples of 348 out of 773 clinically-suspected viral encephalitis patients admitted to different hospitals during the period June to August of 2000 to 2002 were tested for detection of JE specific IgM antibody, employing MAC ELISA test at RMRC (ICMR), Dibrugarh. Diagnosis was confirmed in 53.7% patients with the ratios of 1.8:1 and 1.4:1 for male to female and pediatric to adult patients respectively. Most of the cases were pediatrics at the age of 7 to 12 years (34.2%). Fever (100%), altered sensorium (81.8%), headache (70.6%), neck rigidity (54.0%), abnormal movement (51.3%), exaggerated reflexes (48.1%), restlessness (44.9%), increased muscle tone (35.3%), convulsion (33.7%) and coma (20.9%) were the major clinical findings. The majority of cases (96.3%) were from rural areas. House surroundings close to water bodies, rice cultivation, association with pigs, and climatic conditions were environmental factors affecting the abundance of the potential mosquito vectors of the disease.

Verrallina (Neomacleaya) assamensis, a new species from Assam, India

The adult female, adult male, pupa, and larva of Verrallina (Neomacleaya) assamensis, a new mosquito species, are described from the Dibrugarh District of Assam State, India.

Sociocultural diversity and substance use pattern in Arunachal Pradesh, India

An epidemiological study on substance use was carried out to assess the prevalence and pattern of tobacco, alcohol, and opium being used commonly in ethnographic diverse population of Arunachal Pradesh, India. Representative sample of 5135 people age > or =10 years were interviewed to collect information about their habit of substance use. Over all, prevalence of substance use was 30.9% tobacco (22.8% chewers and 12.1% smokers), 30% alcohol, and 4.8% opium, which vary across location, gender, race, age, education, and occupation. Though tobacco and alcohol was commonly used among all the tribes, but high alcohol use among Tangsa and Tutsa tribes reflects strong cultural belief. Religiously, opium use was low among Christian and Hindu at lower (< 1000 m) altitude, but high among Buddhist, Indigenous, and Hindu living at higher altitude. Among males, high multivariate rate ratio of opium users was seen among the population of high altitude (9.1). Moreover, it was also high among Singpho (7.1) and Khamti (9.7) tribes living in low altitude area, which shows the strong geo-ethnographic influence. Average age at initiation of alcohol use (12.4 years) was significantly lower than tobacco (17.6 years), and opium (23.3 years) indicate social acceptability of alcohol drinking at early age. Use of multiple substances and high prevalence of opium express the alarming situation of substance misuse in the region. Besides few limitations, varied results of socio-cultural and ethnic influences recalls integrated approach to break the traditional belief associated with alcohol and drug abuse from the society.

Entomological observations on dengue vector mosquitoes following a suspected outbreak of dengue in certain parts of Nagaland with a note on their susceptibility to insecticides

Three species of Aedes viz., Aedes albopictus, Aedes aegypti and Aedes annandalei were detected from different breeding sources in and around human habitats during entomological study conducted following an outbreak suspected to be of dengue (which occurred during, 1994) in parts of Medziphema PHC area of Nagaland in two different points of time ie., in the year, 1994 and, 2000. The potential dengue vector, Aedes albopictus showed high preponderance by breeding in all types of containers searched with high Breteau Index (BI) value of 85.0 and 72.72 recorded in, 1994 and, 2000 respectively whereas the BI value for other potential vector, Aedes aegypti was recorded low (4.9) in the year, 1994 with a substantial increase (31.81) in, 2000. The change in ecosystem along with the process of urbanization has facilitated the growth of these dengue vector mosquitoes in the area of investigation. Adults of both Aedes aegypti and Aedes albopictus were found to be susceptible to DDT, dieldrin and malathion in insecticide bioassay carried out using WHO test kit.

Uranotaenia dibrugarhensis, a new species in subgenus Pseudoficalbia from Assam, India

The adult female, adult male, pupa, and larva of Uranotaenia (Pseudoficalbia) dibrugarhensis, new species, are described from the Dibrugarh District of Assam State, India.

A rodent model for pulmonary paragonimiasis

This study reports a model of pulmonary paragonimiasis in outbred Wistar rats using the Indian strain of Paragonimus heterotremus isolated from the fresh water crab Barytelphusa lugubris collected from Arunachal Pradesh, India. Feeding metacercariae to the rats led to encapsulated adult worms in the lungs and pleural cavity. Some flukes migrated to the skeletal muscles of the hosts where they remained underdeveloped as immature flukes.

Therapeutic efficacy of anti-malarials in Plasmodium falciparum malaria in an Indo-Myanmar border area of Arunachal Pradesh

BACKGROUND & OBJECTIVES

Malaria is one of the major public health problems in the north eastern region of India. Antimalarial drug resistance is widespread and one of the important causes of recent resurgence of falciparum malaria in this region. Antimalarial drugs are seen to be used sequentially one after another in many areas of the region, when therapeutic failure is observed with a drug. In view of this, the present study was undertaken to assess the therapeutic efficacy of common antimalarial drugs viz., chloroquine, sulfadoxine+pyrimethamine (S-P) and quinine, administered sequentially to the patients with Plasmodium falciparum infection in a Myanmar bordering area of Arunachal Pradesh.

METHODS

A hospital based in vivo study was carried out with 53 patients with uncomplicated falciparum malaria. All patients were first treated with chloroquine and therapeutic efficacy assessed. In case of therapeutic failure of chloroquine combination drug (S-P) was given and those showing failure with S-P combination, oral quinine was administered and followed up for 28 days to assess both clinical and parasitological responses.

RESULTS

Therapeutic failure was observed with chloroquine in 83.1 per cent (44 of 53) and to both chloroquine and S-P combination drug in 44.1 per cent (19/43) patients. Further, 15.8 per cent patients (3 of 19) failed to respond even to quinine. Overall, 5.7 per cent patients (3 of 53) showed unresponsiveness to all the three drugs i.e., chloroquine, S-P combination and quinine. Asexual parasite clearance and also fever clearance was slowest with chloroquine and fastest with quinine.

INTERPRETATION & CONCLUSION

The findings of this study show the presence of multi drug failure P. falciparum in Jairampur-Nampong, a western Myanmar bordering area of Arunachal Pradesh. Anti malarial drug resistance is increasing in Indo-Myanmar border areas and systematic studies need to be done to review the situation.

The association of selected sociodemographic factors and differences in patterns of substance use: a pilot study in selected areas of Northeast India

Emergence of new addictive substances and progressive increase of 'drug abuse" has become a serious problem in many countries. Despite legal restriction and administrative control, the use of illicit drugs (like opium, heroin, proxyvan, etc.) has increased considerably in many parts of Northeast India. A sample of 1831 people (age 10 years and above) were interviewed during 1997-1998 about their drug use habits, if any, and types of substance used, in Meghalaya and upper Assam. Prevalence of substance use was 29.4% tobacco (20.5% chewers and 12.7% smokers), 12.5% alcohol, and 4.9% opium. In Meghalaya, prevalence of tobacco use was high (41.7%), which was mainly due to the large number of female chewers and male smokers. Opium and cannabis users were mainly confined in Assam close to the Arunachal Pradesh border, indicating a regional influence. Wide differences were observed in the prevalence pattern of tobacco and alcohol use across location, sex, age, education, and occupation. An association of sociodemographic factors with substance use was documented. Religion and ethnic group have significant association with tobacco use patterns but are insignificant with regard to alcohol use. Use of multiple substances and use of cannabis as a substitute for opium are the major problems indicating drug dependence. Mean ages for substance use initiation were: 18.5 years for tobacco, 21.8 years for alcohol, and 25.8 years for opium. Not with-standing the study's limitations, these findings are useful for planned prevention efforts and formulation of a specific program considering the importance of regional and sociodemographic factors.

Hypertension in the elderly population of Assam

BACKGROUND

With the increase in life-expectancy and modification of lifestyle cardiovascular disease especially hypertension is emerging as a major public health problem in the elderly people of Assam. The Geriatric population needs priority in assessment of the disease burden. With this background this study was undertaken with an objective to know the dimension of the hypertension prolem in elderly people of Assam and relevant factors associated with it.

METHODS

Eight hundred and eighty eight elderly participants 60 years and above (males 500, females 388 from three randomly selected areas were interviewed to collect information on dietary habit and socio-demographic variables and clinically examined for blood pressure and athropometric parameters using standardized technique. Statistical analysis was performed using the Epi Info and SPSS software.

RESULTS

To overall age adjusted mean systolic blood pressure (SBP) was 150.52 (95% CI 148.81-152.23) and diastolic blood pressure (DBP) was 88.22 (95% CI 87.39-89.05). Overall prevalence of hypertension was 63.63% (95% CI 59.8-66.2), 64.2% in males and 62.89% in females. Isolated systolic hypertension was detected in 13.2% males and 10.31% females among the hypertensives. 26.90% of the hypertensives were aware of their increase in blood pressure. Determinants of hypertension derived by multiple logistic regression analysis were age, intake of extra salt, alcohol and body mass index (BMI).

CONCLUSION

High prevalence with inadequate awareness and control of hypertension in the elderly group of population call for an immediate implementation of active public health programme in the state.

Estimation of vectorial capacity of Anopheles dirus (Diptera: Culicidae) in a forest-fringed village of Assam (India)

To estimate the vectorial capacity of Anopheles dirus, the main vector of forest malaria in the northeastern region of India, in order to gain an understanding of entomological factors related to malaria transmission in forest-fringe areas of Assam, India, an isolated village in the tropical rain forest-fringed area in the district of Dibrugarh, Assam, under the influence of An. dirus alone was studied. Data on various entomological variables required for computation of the vectorial capacity were generated in each month from June 1999 to May 2000 in the field using standard techniques. Malaria prevalence was also studied during the same period in the study village and correlated with the estimated vectorial capacity of An. dirus. Vectorial capacity of An. dirus was highest, 0.779 for Plasmodium vivax (Pv) and 0.649 for Plasmodium falciparum (Pf), during the hot-monsoon season (June-September) and decreased to 0.08 (Pv) and 0.07(Pf) in the temperate postmonsoon season (October-November) before attaining zero values in the cool-dry season (December-February). With increasing temperature in the temperate premonsoon season (March-May), vectorial capacity recorded was 0.119 and 0.82 for Pv and Pf, respectively. Significant positive correlation was seen between the estimated vectorial capacity of An. dirus and the number of new Pf (r = 0.86, p < 0.001) and Pv (r = 0.69, p < 0.02) cases in the study village in different months. Thus, this study highlights the pattern of malaria transmission by An. dirus in a forest-fringe area of Assam that begins in March, peaks in July/August, subsides by November, and remains interrupted between December and February. Measures for controlling malaria in forest-fringe areas should be scheduled accordingly.