Survey of the present health & nutritional status of Shompen tribe of Great Nicobar Island.

BACKGROUND OBJECTIVES: Shompens are one of the two mongoloid tribes of Nicobar district. There is little information about their recent health status since the last survey which was conducted in 1998. Hence, a comprehensive health and nutritional survey was conducted in March 2017 to assess the changes. The survey was carried out by a joint team of various organizations including the ICMR-Regional Medical Research Centre and Tribal Welfare and Health Department both located in Port Blair. METHODS: A detailed health and nutrition survey of the Shompen community was planned by deputing a field research team. The survey included demographic data, anthropometric data, clinical examination, screening for the markers of infectious diseases, respiratory pathogens, tuberculosis and haemoglobinopathies. RESULTS: About half of the Shompen adults (both males and females) had a body mass index (BMI) of ≥23. However, Shompen children had a good nutritional status with no child suffering from undernutrition. As per BMI for age, none of the children <5 yr were under-nourished, while in the 5-17 yr group, 12 per cent of children were undernourished. Anaemia prevalence was about 48.3 per cent, with 54 per cent prevalence in females and 43.8 per cent in males. Fungal infection of the skin, acute respiratory infection and abdominal pain were the common morbidities observed. None had active pulmonary tuberculosis. Of 38 Shompens screened for IgG (immunoglobulin G) antibodies, 42.1 and 18.4 per cent were positive for measles and rubella, respectively. Seroprevalence of Leptospira was 35.5 per cent. The prevalence of hypertension was 13.2 per cent, whereas another 28.9 per cent were pre-hypertensive. INTERPRETATION CONCLUSIONS: The population structure of the Shompen is not skewed and under nutrition was not widely prevalent among the children of <5 yr. The other positive observations were the absence of malaria, filariasis and dengue. However, there was natural infection of measles and rubella. Fungal skin infection and intestinal parasitic infestations were widely prevalent. Although cardiovascular risk profile was low, there were signs of emerging risk of over-weight, hypertension and dyslipidaemia. These together with the high prevalence of smokeless tobacco use may have a serious effect on the cardiovascular disease susceptibility of the Shompen population in the future.

A population based study on human papillomavirus infection and associated risk factors among women of the remote South Andaman Island, India.

BACKGROUND: Human papillomavirus (HPV) is associated with cervical cancer and cervical dysplasia worldwide. Data on HPV prevalence in a region is important because it serves as a predictor of the likelihood of the population in that particular region acquiring cervical cancer. Moreover, with the availability of effective vaccines, the public health system must be aware of the preponderance of HPV to implement the vaccine. The present study was designed to understand the prevalence of HPV and associated factors among the women of South Andaman Island. METHODS: A cross-sectional study was conducted among married women of reproductive age (18-59 years) from South Andaman District from 2018 to 2022. Cervical scrapes were collected from participants after obtaining informed written consent for HPV molecular testing (HPV DNA) such as PCR assay. Demographic data was collected using a standard questionnaire and statistical analyses were performed to determine the associated factors. RESULTS: The study showed prevalence of HPV as 5.9%(95% CI: 3.9-7.9) and prevalence of HR-HPV16 was 4.1% (95% CI 2.6 - 5.5) and HR-HPV18 prevalence was 1.8(95% CI: 0.6-3). The independent factors associated the HPV positivity were age above 55 years, menopause, post-menopausal bleeding, blood-stained vaginal discharge and loss of weight. Age was associated with all HPV infections among the South Andaman women. CONCLUSIONS: HPV 16 was reported as the predominant high risk HPV type circulating among women of South Andaman. Cervical cancer and precancerous lesions were significantly associated with HPV positivity and High risk HPV 16. Based on the knowledge of the risk factors associated with HPV, implementation of stronger public health awareness and prophylactic HPV vaccination is crucial among the women of this remote island.

Distribution of Human Papillomavirus Genotypes among the Women of South Andaman Island, India.

BACKGROUND: Human Papillomavirus (HPV) causes various types of cancer in both men and women. Woman with HPV infection has a risk of developing invasive cervical cancer. Globally, HPV 16 and 18 were predominant. This study aims to find the distribution of various HPV types in South Andaman. METHODS: A cross-sectional study was conducted among women in South Andaman, where cervical scrapes were collected after collecting written informed consent. Detection of HPV genotypes was carried out by using a PCR assay. Further, sequencing analysis was performed using MEGA11 to identify various genotypes in this territory. RESULT: Of these 1000 samples, 32 were positive for HR-HPV 16, and four were positive for HR-HPV 18. Fifteen HPV genotypes were detected using molecular evolutionary analysis. Six cases were identified with multiple genotypes. The most prevalent genotype is HPV 16 which belongs to Lineage-A and sub-lineage A2. HPV 18 identified in South Andaman belonged to the lineage A1 to A5. DISCUSSION: Various HPV types were identified among women in South Andaman. Global burden of cervical cancer associated with various HPV sub-lineages. HPV-16 A1 sub-lineage was globally widespread, whereas sub-lineages A1, A2 and D1 prevailed in South Andaman. CONCLUSIONS: HR-HPV identified in this study enlightens the importance of HPV vaccination among women in remote places. These findings will help to strengthen public health awareness programs and prevention strategies for women in remote areas.

Expansion of the measles and rubella laboratory network, India.

Objective: To expand the measles and rubella laboratory network of India by integrating new laboratories. Methods: In collaboration with the World Health Organization (WHO), the Indian government developed a 10-step scheme to systematically expand the number of laboratories performing serological and molecular testing for measles and rubella. The Indian Council of Medical Research and WHO identified suitable laboratories based on their geographical location, willingness, preparedness, past performance and adherence to national quality control and quality assurance mechanisms. The 10-step scheme was initiated with training on measles and rubella diagnostic assays followed by testing of both measles and rubella serology and molecular unknown panels, cross-verification with reference laboratories and ended with WHO on-site accreditation. Findings: After extensive training, technical support, funding and monitoring, all six selected laboratories attained passing scores of 90.0% or more in serological and molecular proficiency testing of measles and rubella. Since 2018, the laboratories are a part of the measles and rubella network of India. Within 12 months of initiation of independent reporting, the six laboratories have tested 2287 serum samples and 701 throat or nasopharyngeal swabs or urine samples. Conclusion: The process led to strengthening and expansion of the network. This proficient laboratory network has helped India in scaling up serological and molecular testing of measles and rubella while ensuring high quality testing. The collaborative model developed by the Indian government with WHO can be implemented by other countries for expanding laboratory networks for surveillance of measles and rubella as well as other infectious diseases.

Prevalence of pulmonary tuberculosis among the tribal populations in India.

IMPORTANCE: There is no concrete evidence on the burden of TB among the tribal populations across India except for few studies mainly conducted in Central India with a pooled estimation of 703/100,000 with a high degree of heterogeneity. OBJECTIVE: To estimate the prevalence of TB among the tribal populations in India. DESIGN, PARTICIPANTS, SETTING: A survey using a multistage cluster sampling design was conducted between April 2015 and March 2020 covering 88 villages (clusters) from districts with over 70% tribal majority populations in 17 States across 6 zones of India. The sample populations included individuals ≥15 years old. MAIN OUTCOME AND MEASURES: Eligible participants who were screened through an interview for symptoms suggestive of pulmonary TB (PTB); Two sputum specimens were examined by smear and culture. Prevalence was estimated after multiple imputations for non-coverage and a correction factor of 1.31 was then applied to account for non-inclusion of X-ray screening. RESULTS: A total of 74532 (81.0%) of the 92038 eligible individuals were screened; 2675 (3.6%) were found to have TB symptoms or h/o ATT. The overall prevalence of PTB was 432 per 100,000 populations. The PTB prevalence per 100,000 populations was highest 625 [95% CI: 496-754] in the central zone and least 153 [95% CI: 24-281] in the west zone. Among the 17 states that were covered in this study, Odisha recorded the highest prevalence of 803 [95% CI: 504-1101] and Jammu and Kashmir the lowest 127 [95% CI: 0-310] per 100,000 populations. Findings from multiple logistic regression analysis reflected that those aged 35 years and above, with BMI <18.5 Kgs /m2, h/o ATT, smoking, and/or consuming alcohol had a higher risk of bacteriologically positive PTB. Weight loss was relatively more important symptom associated with tuberculosis among this tribal populations followed by night sweats, blood in sputum, and fever. CONCLUSION AND RELEVANCE: The overall prevalence of PTB among tribal groups is higher than the general populations with a wide variation of prevalence of PTB among the tribal groups at zone and state levels. These findings call for strengthening of the TB control efforts in tribal areas to reduce TB prevalence through tribal community/site-specific intervention programs.

Biochemical analysis of leptospiral LPS explained the difference between pathogenic and non-pathogenic serogroups.

Lipopolysaccharide (LPS) is the major surface antigen of Leptospira. In this study, the genes involved in the LPS biosynthesis were analyzed and compared by bioinformatics tools. Also, the chemical composition analysis of leptospiral lipopolysaccharides (LPS) extracted from 5 pathogenic serovars like Autumnalis, Australis, Ballum, Grippotyphosa, Pomona, and the nonpathogenic serovar Andamana was performed. Methods used were Limulus amebocyte lysate assay (LAL), gas chromatography-mass spectrometry (GC-MS), fourier transform infrared spectroscopy (FT-IR), and nuclear magnetic resonance spectroscopy (NMR). LAL assay showed a significantly higher level of endotoxicity among pathogenic serovars (~0.490 EU/mL) than that of nonpathogenic Andamana (~0.102 EU/mL). FAMES analysis showed the presence of palmitic acid (C16:0), hydroxy lauric acid (3-OH-C12:0), and oleic acid (C18:0). Palmitoleic acid (C16: 1), and 3- hydroxy palmitate (3-OH-C16:0) was detected only in pathogenic serovars. In contrast myristoleic acid (C14:1) and stearic acid (C18:0) were present in Andamana. FTIR analysis revealed C-O-C stretch of esters, 3°ROH functional groups and carbohydrate vibration range were similar among pathogenic serovars. The NMR analysis reveals similarity for 6 deoxy sugars and methyl groups of Autumnalis, Australis, and Ballum. Further, the presence of palmitoleic acid and 3-hydroxy palmitate may be the significant pathogen-associated predisposing factor. This mediates high osmolarity glycerol (HOG) mediated stress response in leptospiral LPS mediated pathogenesis.

Molecular xenomonitoring of diurnally subperiodic Wuchereria bancrofti infection in Aedes (Downsiomyia) niveus (Ludlow, 1903) after nine rounds of Mass Drug Administration in Nancowry Islands, Andaman and Nicobar Islands, India.

A group of four human inhabited Nancowry Islands in Nicobar district in the Andaman and Nicobar Islands, India having a population of 7674 is the lone focus of diurnally sub-periodic Wuchereria bancrofti (DspWB) that is transmitted by Aedes niveus (Ludlow). Microfilaria (Mf) prevalence was above 1% even after nine rounds of Mass Drug Administration (MDA) with DEC and albendazole. Molecular xenomonitoring (MX) was conducted to identify appropriate vector sampling method and assess the impact. BioGents Sentinel traps, gravid traps and human baited double bed nettraps were used in three locations in each village to collect Aedes niveus female mosquitoes. Subsequently daytime man landing collections (MLC) were carried out in all the 25 villages in the islands. Collections were compared in terms of the number of vector mosquitoes captured per trap collection. Females of Ae. niveus were pooled, dried and processed for detecting filarial parasite DNA using RT-PCR assay. Vector infection rate was estimated using PoolScreen software. Only 393 female mosquitoes including 44 Ae. niveus (11.2%) were collected from 459 trap collections using three trapping devices. From 151 MLCs, 2170 Ae. niveus female mosquitoes were collected. The average prevalence of W. bancrofti DNA was 0.43%. Estimated upper 95% CI exceeded the provisional prevalence threshold of 0.1% in all the villages, indicating continued transmission as observed in Mf survey. MLCs could be the choice, for now, to sample Ae. niveus mosquitoes. The PCR assay used in MX for nocturnally periodic bancroftian filariasis could be adopted for DspWB. The vector-parasite MX, can be used to evaluate interventions in this area after further standardization of the protocol.

Coaggregation and biofilm formation of Leptospira with Staphylococcus aureus.

It is not known how Leptospira react to wound or a cut infected with microbes, such as pathogenic Staphylococcus, or their common habitat on oral or nasal mucosal membranes. In the present study, Staphylococcus aureus MTCC-737 showed strong co-aggregation with leptospiral strains (>75%, visual score of + 4) in vitro. All tested strains of Leptospira were able to form biofilm with S. aureus. Scanning electron microscopy analysis revealed intertwined networks of attached cells of L. interrogans and S. aureus, thus providing evidence of a matrix-like structure. This phenomenon may have implications in Leptospira infection, which occurs via cuts and wounds of the skin.

Changing trend in the seroprevalence and risk factors of human leptospirosis in the South Andaman Island, India.

Seroprevalence of leptospirosis among a healthy population of the South Andaman Island was assessed through random sampling. Previous studies have high seroprevalences of up to 55% in general population and 65% in agricultural labourers. The study subjects (1,181 in total, 781 rural and 400 urban) were interviewed and tested for antibodies against Leptospira. Multivariate models were developed to determine the risk factors in the rural and the urban population. The overall seroprevalence was 10.9%, with rural (12.9%) being higher than the urban subjects (7.0%). The commonest infecting serogroup was Icterohaemorrhagiae (53.5%), followed by Grippotyphosa (13.2%). Compared to the earlier observation, seroprevalence was lower and an apparent shift in the infecting serogroup was found. This shift was in concordance with the changing trend in animal population. Significant difference in risk factors, both in rural and urban areas, was also observed. Similar trends in seroprevalence are being observed around the world. Therefore, time to time prevalence studies are needed for the development of effective control measure.

Correlation Between Physicochemical Properties of Soil and Presence of Leptospira.

Leptospirosis is an important global public health problem. Favourable environmental factors are influencing the survival of leptospires in soil, which is an important link in the transmission cycle. The present study was designed to understand the correlation between various soil nutrients and presence of Leptospira in soil samples of different regions of Andaman and Nicobar Islands. The study revealed a significant positive relationship between presence of Leptospira and concentration of iron, manganese and copper in soil. Presence of iron, manganese and copper in the soil may influence the survival and transmission of leptospirosis.

Can Subminimal Inhibitory Concentrations of Antibiotics Induce the Formation of Biofilm in Leptospira?

Antibiotics at subminimal inhibitory concentrations (sub-MICs) are known to induce biofilm formation in numerous bacteria in vitro. In this report, the effect of sub-MIC levels of antibiotics (doxycycline and tetracycline) on biofilm formation by leptospiral reference strains and isolates was investigated. The sub-MIC levels of both tetracycline and doxycycline were able to induce biofilm in some of the leptospiral strains. This is the first report demonstrating the effect of sub-MIC level of antibiotics in inducing biofilm formation in Leptospira. The induction of biofilm may solely be a response to the amount of threshold stress enforced by low levels of antibiotics. The mechanism of biofilm induction by subinhibitory antibiotic concentrations needs to be explored further. Studies are required to understand the clinical relevance of the phenomenon and its contribution to biofilm formation in the host, resulting in the failure of antimicrobial therapy during the treatment of chronic leptospirosis.

Intestinal parasitic infestation among paediatric diarrhoea patients attending hospitals in Port Blair, Andaman and Nicobar Islands.

Acute childhood diarrhoea remains one of the leading causes of childhood morbidity and mortality in developing countries. The present study was conducted to estimate the prevalence of various intestinal parasitic infestation among children aged 5 years and less suffering from acute diarrhoea disease attending hospitals in Andaman Islands. During the period from January 2012 to December 2013, a total of 675 acute diarrhoea patients were included in the study. Among these samples, 476 (70.5, 95 % CI 66.9, 73.9) harboured ova/cyst of one or more intestinal parasites. Ova/cyst and trophozite of intestinal protozoan parasite was present in the stool samples of 390 (57.8, 95 % CI 54.0, 61.5) children whereas ova of helminth parasite was observed in the stool samples of 105 (15.6, 95 % CI 12.9, 18.5) children. Among all the parasites, Giardia lamblia trophozite had the highest prevalence of 30.5 % followed by Entamoeba histolitica cyst (21.0 %). The high prevalence of intestinal protozoan parasites is an indicator of a probably high carrier rate of these parasites in the community. The study is two issues that are important from public health points of view. Protozoan infestations could be the cause of diarrhoea, particularly watery diarrhoea, in a substantial proportion of the childhood diarrhoea patients attending the hospitals and anti-protozoan therapy needs to be part of the treatment regimen for watery diarrhoea among childhood diarrhoea patients. The second is the need for instituting a community based programme for controlling intestinal protozoan carriage in children as well as in adults as a step towards diarrhoea control.

Chelonitoxism in Andaman and Nicobar Island: A report on mass poisoning including a death of an adult.

Chelonitoxism is a type of seafood poisoning which usually occurs due to consumption of certain marine turtle flesh. As the pharmacology or chemistry of the toxin is still unknown, antidote or treatment to chelonitoxism is unavailable. The symptoms can vary from common gastro-intestinal symptoms to neurological manifestations and even death. This case report of community poisoning following consumption of turtle meat includes the death of an adult male (56 yrs.) being reported for the first time in the Great Nicobar Island, Andaman and Nicobar (A&N) Islands, India in August 2012. The patient encountered common gastrointestinal symptoms after one day of ingestion of green turtle flesh and later, he developed neurological symptoms and did not respond to symptomatic treatment and expired after four days after the consumption. However, out of 30 villagers who took the same food, six others developed symptoms and recovered within a period of 3-7 days while two pets (a dog and a cat) died within 24 hours as they were fed with the same food. In spite of several existing wildlife protection acts, catching a turtle and making them a source of food-celebration is quite common in coastal areas of the Indian Ocean and the Bay of Bengal which includes A&N Islands. A proper monitoring and follow-up of the food-borne diseases along with a wide range of explorative health education protocol should be implemented especially for the people who are not reachable via media to avoid such incidents in future.

Rapid and Long-Term Immunity Elicited by DNA-Encoded Antibody Prophylaxis and DNA Vaccination Against Chikungunya Virus.

BACKGROUND: Vaccination and passive antibody therapies are critical for controlling infectious diseases. Passive antibody administration has limitations, including the necessity for purification and multiple injections for efficacy. Vaccination is associated with a lag phase before generation of immunity. Novel approaches reported here utilize the benefits of both methods for the rapid generation of effective immunity. METHODS: A novel antibody-based prophylaxis/therapy entailing the electroporation-mediated delivery of synthetic DNA plasmids encoding biologically active anti-chikungunya virus (CHIKV) envelope monoclonal antibody (dMAb) was designed and evaluated for antiviral efficacy, as well as for the ability to overcome shortcomings inherent with conventional active vaccination and passive immunotherapy. RESULTS: One intramuscular injection of dMAb produced antibodies in vivo more rapidly than active vaccination with an anti-CHIKV DNA vaccine. This dMAb neutralized diverse CHIKV clinical isolates and protected mice from viral challenge. Combination of dMAb and the CHIKV DNA vaccine afforded rapid and long-lived protection. CONCLUSIONS: A DNA-based dMAb strategy induced rapid protection against an emerging viral infection. This method can be combined with DNA vaccination as a novel strategy to provide both short- and long-term protection against this emerging infectious disease. These studies have implications for pathogen treatment and control strategies.

In Vitro Antimicrobial Susceptibility of Pathogenic Leptospira Biofilm.

Pathogenic Leptospira spp. are the causative agent of leptospirosis. Biofilm formation in leptospires is a new area of study, and its role in pathogenesis is not fully explored. As in other biofilm-forming bacteria, Leptospira biofilm may play a significant role in antibiotic resistance. In this study, the antimicrobial susceptibility of Leptospira biofilm was investigated by 96-well plate assay using Alamar Blue. Leptospira biofilm showed five to sixfold increase in resistance in all the strains used. The range of minimal bactericidal concentrations for penicillin G, ampicillin, tetracycline, and doxycycline was 1,600 U/ml, 800-1,600 µg/ml, 800-1,600 µg/ml, and 800-1,600 µg/ml, respectively. In agar substrate, the biofilm showed six- to sevenfold increase in resistance to antibiotics compared to planktonic cell. The present study emphasizes the importance of biofilm formation and its antibiotic susceptibility patterns. This could pave the way for devising appropriate strategy to prevent the occurrence of potential chronic leptospirosis in endemic areas and also during an outbreak situation.

Association of Oligoadenylate Synthetase Gene Cluster and DC-SIGN (CD209) Gene Polymorphisms with Clinical Symptoms in Chikungunya Virus Infection.

Biology and pathogenesis of chikungunya virus (CHIKV) are not clearly established. Host factors play an important role in determining the progression and severity of the disease. Polymorphisms in the promoter region of CD209 gene (rs735239, rs4804803, rs2287886) and OAS1 (rs1131454 and rs10774671), OAS2 (rs15895 and rs1732778), and OAS3 (rs2285932 and rs2072136) genes were investigated in 100 patients with CHIKV infection and 101 healthy controls to find out the association of these polymorphisms with CHIKV infection. To evaluate the association of OAS and CD209 gene polymorphisms with the presence or absence of disease symptoms in CHIKV-infected patients. DNA was extracted and typed using polymerase chain reaction followed by restriction fragment length polymorphism methods. Results revealed that the allele and genotype frequencies of OAS1, OAS3, and OAS2 gene polymorphisms were not different between healthy controls and CHIKV patients. The frequency of CD209 gene G/G genotype of rs4804803 was significantly higher in CHIKV patients compared to healthy controls (p = 0.046). The present study suggests that rs4804803 GG genotype of CD209 gene is associated with susceptibility to CHIKV infection. To conclude, the present preliminary study suggests that OAS gene cluster and CD209 gene polymorphisms influence the risk of developing clinical symptoms in CHIKV-infected patients. Further follow-up studies with a large number of samples are needed to assess the role of these genes in association with post-sequela symptoms observed in CHIKV patients. A detailed research is required in these directions to understand the biology behind CHIKV infection and disease severity.

Medicinal Plants Used by the Nicobarese Inhabiting Little Nicobar Island of the Andaman and Nicobar Archipelago, India.

BACKGROUND: This study is an attempt to document the medicinal plants used by the tribal community of Little Nicobar Island. Despite modern healthcare facilities, tribals often consume medicinal herbs, with traditional knowledge practitioners (TKPs) serving as local medical experts. OBJECTIVES: The aim is to conduct an ethnomedicinal survey among the Nicobarese, whose medicinal practices are yet to be documented. METHODS: Field research was conducted in all five villages of Little Nicobar Island, situated in the southernmost part of the Andaman and Nicobar Archipelago, during 2012-2013. Seven TKPs were interviewed using a questionnaire-guided ethnomedicinal survey protocol. The data obtained were analyzed using the informant consensus factor (ICF) and use value. Voucher specimens of all the cited plant species were deposited at the Regional Medical Research Centre (Indian Council of Medical Research), Port Blair. RESULTS: Uses of 34 medicinal plant species, belonging to 23 families encompassing 32 genera, were recorded during the survey. These 34 species are employed to treat a total of 16 ailments. The highest ICF (1.00) was obtained for respiratory diseases. The Euphorbiaceae family exhibited the highest number of citations, and plants with the highest use values were Glochidion calocarpum Kurz, Senna occidentalis (L.) Link, Ocimum tenuiflorum L., and Passiflora suberosa L. Of the medicinal plants reported, the most common growth form was herbs. Remedies were generally prepared using water. The medicinal plant preparations were administered topically or orally. INTERPRETATION AND CONCLUSIONS: Traditional knowledge of herbal medicines is handed down orally through generations. These plants attained a significant role under the healthcare of the Nicobarese residing in Little Nicobar Island. Efforts to ensure their documentation are necessary in order to prevent its loss, either because of natural calamities or lack of interest among younger generations in carrying out their tradition.