Comparison of risk factors for dementia among rural and urban elderly adults-data from two cohort studies in India.

INTRODUCTION: Studies on risk factors for dementia in India, especially rural India, are sparse and therefore we aimed to assess risk factors in a rural cohort on aging and compare it with an urban cohort. METHODS: We are presenting baseline data on proportion of hypertension, diabetes, obesity, physical inactivity, and Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) scores in both cohorts. RESULTS: The rural cohort is younger and less educated than the urban cohort. The chi-square test showed that the proportion of participants with hypertension, diabetes, and obesity was lower in the rural cohort, whereas physical inactivity was higher in comparison with the urban cohort; however, the proportion of high-risk CAIDE scores was higher in the rural cohort. DISCUSSION: Despite the rural cohort having a smaller proportion of participants with hypertension, diabetes, and obesity, the overall CAIDE score was higher-the main reason for this is low educational level.

Burden of Vitamin D, Vitamin B12 and Folic Acid Deficiencies in an Aging, Rural Indian Community.

Introduction: The important role of micronutrient deficiencies in aging-related disorders including dementia is becoming increasingly evident. However, information on their burden in India is scarce, especially, among aging and rural communities. Methods: Prevalence of vitamin D, B12 and folic acid deficiency was measured in an ongoing, aging cohort, from rural India-Srinivaspura Aging Neurosenescence and COGnition (SANSCOG) study cohort. Serum level estimation of vitamin D, B12 and folic acid, using chemiluminescence immunoassay, was performed on 1648 subjects (872 males, 776 females). Results: Mean vitamin D, B12 and folic acid levels were 23.4 ± 10.6 ng/ml, 277.4 ± 194.4 pg/ml and 6 ± 3.5 ng/ml), respectively. Prevalence of low vitamin D (<30 ng/ml), vitamin D deficiency (<20 ng/ml), B12 deficiency (<200 pg/ml) and folic acid deficiency (<3 ng/ml) were 75.7, 39.1, 42.3, and 11.1%, respectively. Significantly more women had vitamin D deficiency, whereas more men had folic acid deficiency. Women belonging to the oldest age group (≥75 years) had the maximum burden of low vitamin D (94.3%) and folic acid deficiency (21.8%). Discussion: Older, rural-dwelling Indians have high burden of vitamin D and B12 deficiencies, which is concerning given the potentially negative consequences on cognition, immunity and frailty in the aging population. Urgent public health strategies are needed to address this issue and prevent or mitigate adverse consequences.

Descriptive epidemiology of SARS-CoV-2 infection in Karnataka state, South India: Transmission dynamics of symptomatic vs. asymptomatic infections.

BACKGROUND: The huge surge in COVID-19 cases in Karnataka state, India, during early phase of the pandemic especially following return of residents from other states and countries required investigation with respect to transmission dynamics, clinical status, demographics, comorbidities and mortality. Knowledge on the role of symptomatic and asymptomatic cases in transmission of SARS-CoV-2 was not available. METHODS: The study included all the cases reported from March 8 - May 31, 2020. Individuals with a history of international or domestic travel from high burden states, Influenza-like Illness or Severe Acute Respiratory Illness and high-risk contacts of COVID-19 cases were included. Detailed analysis based on contact tracing data available from the line-list of state surveillance unit was performed using cluster network analysis software. FINDINGS: Amongst the 3404 COVID-19 positive cases, 3096 (91%) were asymptomatic while 308 (9%) were symptomatic. Majority of asymptomatic cases were in the age range of 16 and 45 years while symptomatic cases were between 31 and 65 years. Mortality rate was especially higher among middle-aged and elderly cases with co-morbidities, 34/38 (89·4%). Cluster network analysis of 822 cases indicated that the secondary attack rate, size of the cluster and superspreading events were higher when the source case was symptomatic as compared to an asymptomatic. INTERPRETATION: Our findings indicate that both asymptomatic and symptomatic SARS-CoV-2 cases transmit the infection, although symptomatic cases were the main driving force within the state during the beginning of the pandemic. Considering the large proportion of asymptomatic cases, their ability to spread infection cannot be overlooked. Notwithstanding the limitations and bias in identifying asymptomatic cases, the findings have major implications for testing policies. Active search, early testing and treatment of symptomatic elderly patients with comorbidities should be prioritized for containing the spread of COVID-19 and reducing mortality. FUNDING: Intermediate Fellowship, Wellcome Trust-DBT India Alliance to Giridhara R Babu, Grant number: IA/CPHI/14/1/501499.

Genomic epidemiology reveals multiple introductions and spread of SARS-CoV-2 in the Indian state of Karnataka.

Karnataka, a state in south India, reported its first case of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection on March 8, 2020, more than a month after the first case was reported in India. We used a combination of contact tracing and genomic epidemiology to trace the spread of SARS-CoV-2 in the state up until May 21, 2020 (1578 cases). We obtained 91 genomes of SARS-CoV-2 which clustered into seven lineages (Pangolin lineages-A, B, B.1, B.1.80, B.1.1, B.4, and B.6). The lineages in Karnataka were known to be circulating in China, Southeast Asia, Iran, Europe and other parts of India and are likely to have been imported into the state both by international and domestic travel. Our sequences grouped into 17 contact clusters and 24 cases with no known contacts. We found 14 of the 17 contact clusters had a single lineage of the virus, consistent with multiple introductions and most (12/17) were contained within a single district, reflecting local spread. In most of the 17 clusters, the index case (12/17) and spreaders (11/17) were symptomatic. Of the 91 sequences, 47 belonged to the B.6 lineage, including eleven of 24 cases with no known contact, indicating ongoing transmission of this lineage in the state. Genomic epidemiology of SARS-CoV-2 in Karnataka suggests multiple introductions of the virus followed by local transmission in parallel with ongoing viral evolution. This is the first study from India combining genomic data with epidemiological information emphasizing the need for an integrated approach to outbreak response.