Rapid Decline of SARS-CoV-2 Viral Load in Single vs. Double-Dose (Short-Interval <6 Weeks) ChAdOx nCoV-19 Vaccinated Health-Care Workers.

The present work was carried out during the emergence of Delta Variant of Concern (VoC) and aimed to study the change in SARS CoV-2 viral load in Covishield vaccinated asymptomatic/mildly symptomatic health-care workers (HCWs) to find out the optimum isolation period. The SARS CoV-2 viral load was carried out in sequential samples of 55 eligible HCWs which included unvaccinated (UnV; n = 11), single-dose vaccinated (SDV, n = 20) and double-dose vaccinated [DDV, n = 24; short-interval (<6 weeks)] subjects. The mean load of envelope (E) gene on day 5 in SDV [0.42 × 105 copies/reaction] was significantly lower as compared to DDV [6.3 × 105 copies/reaction, P = 0.005] and UnV [6.6 × 105 copies/reaction, P = 0.001] groups. The rate of decline of SARS CoV-2 viral load in the initial 5 days of PCR positivity was significantly higher in SDV as compared to that in DDV (Mean log decline 0.39 vs. 0.19; P < 0.001). This was possibly due to interference of adenoviral immunity of first dose of adenovirus-vectored vaccine in double-dose vaccinated HCWs who had received vaccines within a shorter interval (<6 weeks).

An Evaluation of Malaria Surveillance System in Punjab, India, 2020.

Background: India accounted for 6% of global burden of malaria with 95% population residing in malaria endemic areas. However, Punjab is in the malaria elimination phase with annual parasite incidence (API) <1/1000 population. Objectives: We evaluated malaria surveillance system in Punjab using CDC's updated guidelines for evaluating public health surveillance systems to provide recommendations for strengthening the existing system and to overcome the challenges in the path of malaria free Punjab. Methods: We chose two districts of Punjab, Amritsar (lowest API) and Mansa (highest API), interviewed stakeholders, and performed a retrospective desk review. We evaluated the overall usefulness of the system and assessed seven attributes at state, district, health facility, and village level during July-August 2020. Results: In Punjab, there was progressive decline in the malaria cases from 2,955 cases in 2009 to 1,140 in 2019 and no malaria deaths since 2011. Regarding various attributes, overall score for flexibility was good (85.9%); average for simplicity (77%), acceptability (74%), data quality (74%), and timeliness (70%); and poor for representativeness (59%) and stability (57%). Conclusions: Malaria surveillance system was useful in analyzing the trends of morbidity and mortality and for generating data to drive policy decisions. To improve stability, representativeness, and acceptability, surveillance staff should not be engaged in supplemental work, and reports from private sector must be ensured. Supportive supervision and regular trainings should be carried out regarding reporting formats, guidelines, and timely epidemiological investigations to improve timeliness, data quality, and simplicity.

Evaluation of Scrub Typhus Surveillance, Alwar District, Rajasthan, India, July-August 2020.

Introduction: Scrub typhus is one of the most underreported and fatal illnesses accounting for 23% of all febrile illness. Rajasthan reported cases during 2018-2019 in state reporting system but did not report any case to central Integrated Disease Surveillance Programme (IDSP) unit. We evaluated the Scrub typhus surveillance system in Alwar district, Rajasthan, with the objective of describing and evaluating the system and providing evidence-based recommendations to identify gaps. Material and Methods: In cross-sectional study, we reviewed records and conducted key informant interviews at district- and block-level health facilities. Using US Centers for Disease Control guidelines, we evaluated the system by framing indicators for selected attributes for a defined reference period. Overall performance was ranked as outstanding (90-100%), excellent (80-89%), very good (70-79%), good (60-69%), and poor (<60%). Results: Line list of confirmed cases was sent from district to block level for additional active case search (ACS) to implement control measures. We conducted 26 key informant interviews and reviewed records and calculated simplicity as 79%, flexibility 100%, data quality 46%, acceptability 92%, representativeness 48%, timeliness 43%, and stability 79%. Conclusions: Epidemiological surveillance (active and passive) is a core intervention under scrub typhus surveillance system. Lab reports were incompletely uploaded on IDSP portal. Surveillance reports should be updated after each ACS. Reporting format under IDSP should be uploaded timely, and lab reports from state should be sent within 48 hours of diagnosis so that case investigation is not delayed.

Litchi consumption and missed meals continue to be associated with acute encephalopathy syndrome among children: an investigation of the 2019 outbreak in Muzaffarpur district, Bihar, India.

BACKGROUND: Muzaffarpur district in Bihar State of India recorded a resurgence of acute encephalopathy syndrome (AES) cases in the summer of 2019 after no reported outbreak in 3 y. Earlier studies generated evidence that litchi consumption and missing the previous evening's meal were associated with AES. We investigated the recent outbreak to understand the risk factors associated with AES. METHODS: We conducted a matched case-control study by comparing AES cases with healthy controls from case-households and the neighborhood community for risk factors like missing evening meal and litchi consumption before onset of AES. RESULTS: We recruited 61 cases and 239 controls. Compared with the community controls, case-patients were five times more likely to have reported eating litchi in the 7 d preceding the onset of illness (adjusted OR [AOR]=5.1; 95% CI 1.3 to 19) and skipping the previous evening's meal (AOR=5.2; 95% CI 1.4 to 20). Compared with household controls, case-patients were five times more likely to be children aged <5 y (AOR=5.3; 95% CI 1.3 to 22) and seven times more likely to have skipped the previous evening's meal (AOR=7.4; 95% CI 1.7 to 34). CONCLUSIONS: Skipping the previous evening's meal and litchi consumption were significantly associated with AES among children in Muzaffarpur and adjoining districts of Bihar.

India Field Epidemiology Training Program Response to COVID-19 Pandemic, 2020-2021.

The India Field Epidemiology Training Program (FETP) has played a critical role in India's response to the ongoing COVID-19 pandemic. During March 2020-June 2021, a total of 123 FETP officers from across 3 training hubs were deployed in support of India's efforts to combat COVID-19. FETP officers have successfully mitigated the effect of COVID-19 on persons in India by conducting cluster outbreak investigations, performing surveillance system evaluations, and developing infection prevention and control tools and guidelines. This report discusses the successes of select COVID-19 pandemic response activities undertaken by current India FETP officers and proposes a pathway to augmenting India's pandemic preparedness and response efforts through expansion of this network and a strengthened frontline public health workforce.

Evaluation of point of entry surveillance for COVID-19 at Mumbai international airport, India, July 2020.

India started Point of entry (PoE) surveillance at Mumbai International Airport, screening passengers returning from coronavirus disease (COVID-19)-affected countries using infrared thermometers. We evaluated in July 2020 for March 1-22 with the Centers for Disease Control and Prevention evaluation framework. We conducted key informant interviews, reviewed passenger self-reporting forms (SRFs) (randomly selected) and relevant Airport Health Organization and Integrated Disease Surveillance Programme (IDSP) records. Of screened 165,882 passengers, three suspects were detected and all were reverse transcription-polymerase chain reaction negative. Passengers under-quarantine line-listing not available in paper-based PoE system, eight written complaints: 6/8 SRF filling inconvenience, 3/8 no SRF filling inflight announcements, and standing in long queues for their submission. Outside staff deployed 128/150 (85.3%), and staff: passenger ratio was 1:300. IDSP reported 59 COVID-19 confirmed cases against zero detected at PoE. It was simple, timely, flexible, and useful in providing information to IDSP but missed cases at PoE and had poor stability. We recommended dedicated workforce and data integration with IDSP.

Risk factors for melioidosis in Udupi District, Karnataka, India, January 2017-July 2018.

We initiated an epidemiological investigation following the death of a previously healthy 17 year-old boy with neuro-melioidosis. A case was defined as a culture-confirmed melioidosis patient from Udupi district admitted to hospital A from January 2013-July 2018. For the case control study, we enrolled a subset of cases admitted to hospital A from January 2017- July 2018. A control was resident of Udupi district admitted to hospital A in July 2018 with a non-infectious condition. Using a matched case-control design, we compared each case to 3 controls using age and sex groups. We assessed for risk factors related to water storage, activities of daily living, injuries and environmental exposures (three months prior to hospitalization), using conditional regression analysis. We identified 50 cases with case fatality rate 16%. Uncontrolled diabetes mellitus was present in 84% cases and 66% of cases occurred between May and October (rainy season). Percutaneous inoculation through exposure to stagnant water and injury leading to breakage in the skin were identified as an important mode of transmission. We used these findings to develop a surveillance case definition and initiated training of the district laboratory for melioidosis diagnosis.

Comparing COVID-19 mortality across selected states in India: The role of age structure.

BACKGROUND: Mortality rates provide an opportunity to identify and act on the health system intervention for preventing deaths. Hence, it is essential to appreciate the influence of age structure while reporting mortality for a better summary of the magnitude of the epidemic. OBJECTIVES: We described and compared the pattern of COVID-19 mortality standardized by age between selected states and India from January to November 2020. METHODS: We initially estimated the Indian population for 2020 using the decadal growth rate from the previous census (2011). This was followed by estimations of crude and age-adjusted mortality rate per million for India and the selected states. We used this information to perform indirect-standardization and derive the age-standardized mortality rates for the states for comparison. In addition, we derived a ratio for age-standardized mortality to compare across age groups within the state. We extracted information regarding COVID-19 deaths from the Integrated Disease Surveillance Programme special surveillance portal up to November 16, 2020. RESULTS: The crude mortality rate of India stands at 88.9 per million population (118,883/1,337,328,910). Age-adjusted mortality rate (per-million) was highest for Delhi (300.5) and lowest for Kerala (35.9). The age-standardized mortality rate (per million) for India is (<15 years = 1.6, 15-29 years = 6.3, 30-44 years = 35.9, 45-59 years = 198.8, 60-74 years = 571.2, ≥75 years = 931.6). The ratios for age-standardized mortality increase proportionately from 45 to 59 years age group across all the states. CONCLUSION: There is high COVID-19 mortality not only among the elderly ages, but we also identified heavy impact of COVID-19 on the working population. Therefore, we recommend further evaluation of age-adjusted mortality for all States and inclusion of variables like gender, socio-economic status for standardization while identifying at-risk populations and implementing priority public health actions.

Foodborne Disease outbreak associated with eating Gaajar Halwa at a Wedding - Palghar District, Maharashtra, India, 2018.

BACKGROUND: A foodborne disease outbreak among wedding attendees from Makunsar village, Palghar district, Maharashtra state, India, was reported on February 18, 2018. OBJECTIVES: The outbreak investigation was conducted to find out the epidemiology of the outbreak and to identify the etiologic agent and risk factors. METHODS: A case-control study was carried out, where cases (patients), controls, and food handlers were interviewed and leftover foods were collected for culture. A case was defined as a person having vomiting or diarrhea (i.e., ≥3 loose stools within 24 h) who attended the wedding ceremony at Makunsar village, Palghar district, Maharashtra, on February 18, 2018. Attack rate and odds ratio (OR) were calculated with 95% confidence intervals (CIs). RESULTS: Out of 75 cases, 63% were female. Altogether, forty-two (56%) cases were hospitalized, and later on, all of them were discharged from hospital without any mortality. About 93%, 68%, 43%, and 41% of the cases reported with vomiting, nausea, abdominal pain, and diarrhea, respectively. The median incubation period was found to be 4 h (range: 2-8 h). Eating gaajar halwa (carrot pudding) was significantly associated with illness (OR: 12.8; 95% CI: 3.5-46). Gaajar halwa is prepared with khoa, a perishable milk product. The gaajar halwa culture yielded no growth. CONCLUSION: The case-patients' clinical presentation and incubation period were consistent with enterotoxin-producing Staphylococcus aureus as the probable etiologic agent. The epidemiologic investigation identified the probable etiologic agent and food source in a low-resource community setting. Community food handlers were educated on food preparation hygiene and safe storage measures to prevent future outbreaks.

Measles outbreak investigation at Indo-Myanmar border, Longding District, Arunachal Pradesh, India, 2017.

BACKGROUND: On May 23, 2017, the health authorities in Longding district, Arunachal Pradesh, India, reported four suspected measles-related deaths in Konsa village, a remote village on the Indo-Myanmar border. OBJECTIVE: We investigated to describe the epidemiology of the outbreak and identify associated risk factors. METHODS: We defined a measles case as fever and maculopapular rash with cough, coryza, or conjunctivitis in a village of Longding district resident from March 1 to June 18, 2017. In Konsa village, we conducted a retrospective cohort study of children ≤5 years. We calculated attack rate (AR), case fatality rate (CFR), measles-containing vaccine first dose (MCV1) and Vitamin A coverage, risk ratio (RR), and vaccine efficacy. We collected samples for laboratory confirmation. We conducted a routine immunization system evaluation at multiple levels of Longding district. RESULTS: We identified 75 suspected cases (56% females) for a Konsa village-specific AR of 86% (75/87) among children ≤5 years; the median age was 36 months; CFR was 7% (5/75); all deaths unvaccinated; none received Vitamin A. Coverage for MCV1 was 9.2% (6/65) and Vitamin A 4.6% (3/65). No MCV1 (RR = 7.3, 95% confidence interval [CI] = 1.3-53) and participation in a recent local festival (RR = 5.3, 95% CI = 1.5-18.5) were associated with illness. MCV vaccine efficacy was 100%. Of 17 cases, 13 tested positive for measles. The local health facility had neither staff nor immunization microplans. CONCLUSIONS: This outbreak was likely due to low MCV1 and Vitamin A coverage due to poor health-care access. The investigation led to a district measles catch-up campaign and resumption of regular immunization.

Shellfish poisoning outbreaks in Cuddalore District, Tamil Nadu, India.

BACKGROUND: Two suspected shellfish poisoning events were reported in Cuddalore District in Tamil Nadu, India, between January and April 2015. OBJECTIVES: The study was conducted to confirm the outbreaks and to identify the source and risk factors. METHODS: For both outbreaks, a case was defined as a person with nausea, vomiting, or dizziness. Sociodemographic details and symptoms were noted down. Data were also collected in a standard 3-day food frequency questionnaire, along with a collection of clam samples. A case-control study was initiated in the April outbreak. Stool samples were collected from cases, and clam vendors were interviewed. RESULTS: In an outbreak that happened in January, all the twenty people reported to be consumed clams were diagnosed as cases (100% attack rate, 100% exposure rate). In the April outbreak, we identified 199 cases (95% attack rate). In both outbreaks, the clams were identified as genus Meretrix meretrix. The most common reported symptoms were dizziness and vomiting. The clams heated and consumed within 30-60 min. No heavy metals or chemicals were detected in the clams, but assays for testing shellfish toxins were unavailable. All 64 selected cases reported clam consumption (100% exposure rate) as did 11 controls (17% exposure rate). Illness was associated with a history of eating of clams (odds ratio = 314, 95% confidence interval = 39-512). Of the six stool samples tested, all were culture negative for Salmonella, Shigella, and Vibrio cholerae. The water at both sites was contaminated with garbage and sewage. CONCLUSION: Coordinated and timely efforts by a multidisciplinary team of epidemiologists, marine biologists, and food safety officers led to the outbreaks' containment.

Acute diarrheal disease outbreak in Muzaffarpur Village, Chandauli District, Uttar Pradesh, India.

BACKGROUND: Acute diarrheal disease (ADD) outbreaks frequently occur in the Gangetic plains of Uttar Pradesh, India. In August 2017, Muzaffarpur village, Uttar Pradesh, reported an ADD outbreak. OBJECTIVES: Outbreak investigation was conducted to find out the epidemiology and to identify the risk factors. METHODS: A 1:1 area-matched case-control study was conducted. Suspected ADD case was defined as ≥3 loose stools or vomiting within 24 h in a Muzaffarpur resident between August 7 and September 9, 2017. A control was defined as an absence of loose stools and vomiting in a resident between August 7 and September 9, 2017. A matched odds ratio (mOR) with 95% confidence intervals (CIs) was calculated. Drinking water was assessed to test for the presence of any contamination. Stool specimens were tested for Vibrio cholerae, and water samples were also tested for any fecal contamination and residual chlorine. RESULTS: Among 70 cases (female = 60%; median age = 12 years, range = 3 months-70 years), two cases died and 35 cases were hospitalized. Area-A in Muzaffarpur had the highest attack rate (8%). The index case washed soiled clothes at well - A1 1 week before other cases occurred. Among 67 case-control pairs, water consumption from well-A1 (mOR: 43.00; 95% CI: 2.60-709.88) and not washing hands with soap (mOR: 2.87; 95% CI: 1.28-6.42) were associated with illness. All seven stool specimens tested negative for V. cholerae. All six water samples, including one from well-A1, tested positive for fecal contamination with <0.2 ppm of residual chlorine. CONCLUSION: This outbreak was associated with consumption of contaminated well water and hand hygiene. We recommended safe water provision, covering wells, handwashing with soap, access to toilets, and improved laboratory capacity for testing diarrheal pathogens.

Foodborne illness outbreak linked to a rural community kitchen in a rural area of Patiala District, Punjab, India, 2018.

BACKGROUND: In December 2018, an acute gastroenteritis outbreak was reported from Faridpur-Gujjran village, Patiala district, Punjab, India. OBJECTIVE: The objective of this study was to describe the epidemiology and risk factors of the outbreak and recommend prevention measures. METHODS: We conducted a descriptive study and a retrospective cohort study in the village. We defined a case as vomiting or ≥3 loose feces in 24 h plus abdominal pain and/or fever in a resident of the village during December 23-28, 2018. To find cases, we conducted a house-to-house survey; to identify risk factors, we conducted a retrospective cohort study. Fecal specimens were tested for enteric pathogens; water samples were tested for fecal contamination. We also interviewed food handlers. We compared attack rates by level of exposure. From the cohort study, we calculated risk ratios with 95% confidence intervals. RESULTS: From the 261 residents of the village, we identified 116 cases (attack rate 44%) and no deaths. The median age of affected persons was 27.5 years (range 0.5-80 years). The illness was associated with eating in a community kitchen of a temple during December 23-24, 2018. Eating mixed vegetables was associated with illness. We found no pathogens in fecal specimens. All three water samples showed coliform contamination. Cooked food had been left at room temperature before serving. CONCLUSION: Improper storage practices might have led to microbial proliferation of the food served. Our findings will help guide the enforcement of food safety policies for community kitchens.

Addressing Reemergence of Diphtheria among Adolescents through Program Integration in India.

We report a diphtheria outbreak mostly among children (median 12 years; range 4-26 years) of a religious minority in urban India. Case-fatality rate (15%, 19/124) was higher among unimmunized patients (relative risk 4.1, 95% CI 1.5-11.7). We recommend mandating and integrating immunization into school health programs to prevent reemergence.

Disease surveillance during a large religious mass gathering in India: The Prayagraj Kumbh 2019 experience.

BACKGROUND: Mass gathering (MG) events are associated with public health risks. During the period January 14 to March 4, 2019, Kumbh Mela in Prayagraj, India was attended by an estimated 120 million visitors. An onsite disease surveillance was established to identify and respond to disease outbreaks. METHODS: A health coordination committee was established for planning. Disease surveillance was prioritized and risk assessment was done to identify diseases/conditions based on epidemic potential, severity of illness, and reporting requirement under the International Health Regulations (IHR) of 2005. A daily indicator and event-based disease surveillance was planned. The indicator-based surveillance (IBS) manually and electronically recorded data from patient hospital visits and collected MG area water testing data to assess trends. The event-based surveillance (EBS) helped identify outbreak signals based on pre-identified event triggers from the media, private health facilities, and the food safety department. Epidemic intelligence was used to analyse the data and events to detect signals, verify alerts, and initiate the response. RESULTS: At Kumbh Mela, disease surveillance was established for 22 acute diseases/syndromes. Sixty-five health facilities reported 156 154 illnesses (21% of a total 738 526 hospital encounters). Among the reported illnesses, 95% (n = 148 834) were communicable diseases such as acute respiratory illness (n = 52 504, 5%), acute fever (n = 41 957, 28%), and skin infections (n = 27 094, 18%). The remaining 5% (n = 7300) were non-communicable diseases (injuries n = 6601, 90%; hypothermia n = 224, 3%; burns n = 210, 3%). Water samples tested inadequate for residual chlorine in 20% of samples (102/521). The incident command centre generated 12 early warning signals from IBS and EBS: acute diarrheal disease (n = 8, 66%), vector-borne disease (n = 2, 16%), vaccine-preventable disease (n = 1, 8%), and thermal event (n = 1, 8%). There were two outbreaks (acute gastroenteritis and chickenpox) that were investigated and controlled. CONCLUSIONS: This onsite disease surveillance imparted a public health legacy by successfully implementing an epidemic intelligence enabled system for early disease detection and response to monitor public health risks. Acute respiratory illnesses emerged as a leading cause of morbidity among visitors. Future MG events should include disease surveillance as part of planning and augment capacity for acute respiratory illness diagnosis and management.

Cholera outbreak investigation, Bhadola, Delhi, India, April-May 2018.

BACKGROUND: In the Gangetic plains of India, including Delhi, cholera is endemic. On 10 May 2018, staff at the north Delhi district surveillance unit identified a laboratory-confirmed cholera outbreak when five people tested positive for Vibrio cholerae O1 Ogawa serotype in Bhadola. We investigated to identify risk factors and recommend prevention measures. METHODS: We defined a case as ≥3 loose stools within 24 h in a Bhadola resident during 1 April-29 May 2018. We searched for cases house-to-house. In a 1 : 1 unmatched case control study, a control was defined as an absence of loose stools in a Bhadola resident during 1 April-29 May 2018. We selected cases and controls randomly. We tested stool samples for Vibrio cholerae by culture. We tested drinking water for fecal contamination. Using multivariable logistic regression we calculated adjusted ORs (aORs) with 95% CIs. RESULTS: We identified 129 cases; the median age was 14.5 y, 52% were females, 27% were hospitalized and there were no deaths. Symptoms were abdominal pain (54%), vomiting (44%) and fever (29%). Among 90 cases and controls, the odds of illness were higher for drinking untreated municipal water (aOR=2.3; 95% CI 1.0 to 6.2) and not knowing about diarrhea transmission (aOR=4.9; 95% CI 1.0 to 21.1). Of 12 stool samples, 6 (50%) tested positive for Vibrio cholerae O1 Ogawa serotype. Of 15 water samples, 8 (53%) showed growth of fecal coliforms. CONCLUSIONS: This laboratory-confirmed cholera outbreak associated with drinking untreated municipal water and lack of knowledge of diarrhea transmission triggered public health action in Bhadola, Delhi.

An outbreak of acute skin and soft tissue infections including necrotizing fasciitis in Kalwala village, India, 2018: Public health implications for the lymphatic filariasis elimination program.

BACKGROUND: A cluster of 15 acute skin and soft tissue infections (SSTIs), including two cases of necrotizing fasciitis, reported in July 2018 from Kalwala village, led us to investigate and describe their epidemiology and to provide recommendations. METHODS: Cases, defined as localized painful swelling and redness in Kalwala residents from 1 December 2017 to 20 August 2018, were identified from hospital records and house-to-house surveys. We conducted an unmatched case-control study to identify risk factors for severity. We cultured wound samples and environmental samples from wound-dressing stations. RESULTS: We identified 36 cases (median age: 55 [range 17-80] y; 78% male), village attack rate 1% (36/4337) and no deaths. In 34 cases (94%), lower limbs were involved. Lymphatic filariasis (LF) was a common predisposing condition (67%). Comorbidities (diabetes or hypertension) (OR=9; 95% CI 2.0 to 41.1), poor limb hygiene (OR=16; 95% CI 2.8 to 95.3) and poor health-seeking behavior (OR=5; 95% CI 1.6 to 30.8) were associated with severity. All seven wound samples and 8/11 samples from wound-dressing stations showed atypical polymicrobial growth (Pseudomonas, Proteus, Klebsiella, Escherichia coli and Clostridium). CONCLUSION: The outbreak of SSTIs among older males with LF was due to secondary bacterial infections and severity was associated with comorbidities, poor hygiene and health-seeking behavior, and likely contamination during wound-dressing. The LF elimination program managers was alerted, programmatic interventions were scaled up, home/facility-based morbidity and comorbidity management was facilitated and the outbreak was rapidly contained.

Impact of nonpharmacological interventions on COVID-19 transmission dynamics in India.

BACKGROUND: As of May 4, 2020, India has reported 42,836 confirmed cases and 1,389 deaths from COVID-19. India's multipronged response included nonpharmacological interventions (NPIs) like intensive case-based surveillance, expanding testing capacity, social distancing, health promotion, and progressive travel restrictions leading to a complete halt of international and domestic movements (lockdown). OBJECTIVES: We studied the impact of NPI on transmission dynamics of COVID-19 epidemic in India and estimated the minimum level of herd immunity required to halt it. METHODS: We plotted time distribution, estimated basic (R0) and time-dependent effective (Rt) reproduction numbers using software R, and calculated doubling time, the growth rate for confirmed cases from January 30 to May 4, 2020. Herd immunity was estimated using the latest Rtvalue. RESULTS: Time distribution showed a propagated epidemic with subexponential growth. Average growth rate, 21% in the beginning, reduced to 6% after an extended lockdown (May 3). Based on early transmission dynamics, R0was 2.38 (95% confidence interval [CI] =1.79-3.07). Early, unmitigated Rt= 2.51 (95% CI = 2.05-3.14) (March 15) reduced to 1.28 (95% CI = 1.22-1.32) and was 1.83 (95% CI = 1.71-1.93) at the end of lockdown Phase 1 (April 14) and 2 (May 3), respectively. Similarly, average early doubling time (4.3 days) (standard deviation [SD] = 1.86) increased to 5.4 days (SD = 1.03) and 10.9 days (SD = 2.19). Estimated minimum 621 million recoveries are required to halt COVID-19 spread if Rtremains below 2. CONCLUSION: India's early response, especially stringent lockdown, has slowed COVID-19 epidemic. Increased testing, intensive case-based surveillance and containment efforts, modulated movement restrictions while protecting the vulnerable population, and continuous monitoring of transmission dynamics should be a way forward in the absence of effective treatment, vaccine, and undetermined postinfection immunity.

A community-wide acute diarrheal disease outbreak associated with drinking contaminated water from shallow bore-wells in a tribal village, India, 2017.

BACKGROUND: In 2016, India reported 709 acute diarrheal disease (ADD) outbreaks (> 25% of all outbreaks). Tribal populations are at higher risk with 27% not having accessibility to safe drinking water and 75% households not having toilets. On June 26, 2017 Pedda-Gujjul-Thanda, a tribal village reported an acute diarrheal disease (ADD) outbreak. We investigated to describe the epidemiology, identify risk factors, and provide evidence-based recommendations. METHODS: We defined a case as ≥3 loose stools within 24 h in Pedda-Gujjul-Thanda residents from June 24-30, 2017. We identified cases by reviewing hospital records and house-to-house survey. We conducted a retrospective cohort study and collected stool samples for culture. We assessed drinking water supply and sanitation practices and tested water samples for faecal-contamination. RESULTS: We identified 191 cases (65% females) with median age 36 years (range 4-80 years) and no deaths. The attack-rate (AR) was 37% (191/512). Downhill colonies (located on slope of hilly terrains of the village) reported higher ARs (56%[136/243], p < 0.001) than others (20%[55/269]). Symptoms included diarrhea (100%), fever (17%), vomiting (16%) and abdominal pain (13%). Drinking water from five shallow bore-wells located in downhill colonies was significantly associated with illness (RR = 4.6, 95%CI = 3.4-6.1 and population attributable fraction 61%). In multi-variate analysis, drinking water from the shallow bore-wells located in downhill colonies (aOR = 7.9, [95% CI =4.7-13.2]), illiteracy (aOR =6, [95% CI = 3.6-10.1]), good hand-washing practice (aOR = 0.4, [95%CI = 0.2-0.7]) and household water treatment (aOR = 0.3, [95%CI = 0.2-0.5]) were significantly associated with illness. Two stool cultures were negative for Vibrio cholerae. Heavy rainfall was reported from June 22-24. Five of six water samples collected from shallow bore-wells located in downhill colonies were positive for faecal contamination. CONCLUSION: An ADD outbreak with high attack rate in a remote tribal village was associated with drinking water from shallow downhill bore-wells, likely contaminated via runoff from open defecation areas after heavy rains. Based on our recommendations, immediate public health actions including repair of leakages at contaminated water sources and alternative supply of purified canned drinking water to families, and as long-term public health measures construction of house-hold latrines and piped-water supply initiated.