BACKGROUND: In Zambia, the true extent of SARS-CoV-2 infections is unknown because initial surveillance focused on patients with symptoms or severe disease. Antenatal sentinel surveillance had not been used to assess infection trends. The ANC COVID-19 surveillance study sought to determine SARS-CoV-2 seroprevalence and COVID-19 vaccine uptake among pregnant women. We provide insight into the study implementation, challenges encountered, best practices, and lessons learned. METHODS: A repeated cross-sectional seroprevalence survey was implemented at 39 health facilities in four districts from September 2021 to September 2022. Pregnant women aged 15-49 years were enrolled at their first antenatal care visits. An electronic questionnaire gathered demographics and other COVID-19 related information from consenting participants. A dried blood sample was collected to detect IgG antibodies using a multiplex bead assay. Seropositive results were categorized as infection, infection and vaccination or infection based on anti-RBD and anti-nucleocapsid test results. Problems and their root causes were identified as they occurred. Practical problem-solving strategies were devised, implemented, and monitored to ensure that goals were accomplished. RESULTS: In the primary analysis, 7% of the 9,221 samples collected from participants were not tested because they were missing. COVID-19 vaccine uptake of 9,111 pregnant women was assessed. Approximately 64% of participants were cumulatively seropositive for SARS-CoV-2 antibodies. Seroprevalence increased from 27.8% in September 2021 to 56.6% in July 2022. We observed an increase in vaccine coverage (0.5-27%) over time. Women aged 40-49 years old, without education and with prior COVID-19 infection were associated with higher vaccine uptake. The Delta variant of COVID-19 and the reallocation of health facilities between two partners delayed surveillance activities and increased the cost of implementation (e.g., the purchase of additional calibration and validation kits and DBS cards). Protocol deviations were attributed to the lack of experience in conducting research but, the district RAs repeatedly trained health facility staff to enhance their research knowledge. CONCLUSIONS: Incorporating SARS-CoV-2 surveillance into routine antenatal care is feasible and potentially sustainable when existing health system infrastructure, human resources, and surveillance systems are leveraged. Yet, careful planning is needed to anticipate implementation challenges and ensure high-quality data collection.

Subacute sclerosing panencephalitis (SSPE) is a lethal neurological disorder occurring several years after measles. Reconstruction of the evolution of the measles virus (MeV) genome in an SSPE case suggested that the matrix (M) protein mutation M-F50S, when added to other mutations, drove neuropathogenesis. However, whether and how M-F50S would promote spread independently from other mutations was in question. We investigated here the cell specificity of MeV spread in this brain and documented that both neurons and astrocytes were heavily infected. We then generated recombinant MeV with individual mutations in the three proteins of the viral membrane fusion apparatus, M, fusion (F), and hemagglutinin (H). These viruses reached similar titers as the parental wild-type virus, kept the respective mutations upon passage, and infected cells expressing the tissue-specific MeV receptors SLAM and nectin-4 with similar efficiencies. However, after inoculation of receptor-negative neurons and astrocytes differentiated from human induced pluripotent stem cells, only MeV M-F50S spread with moderate efficiency; the parental virus and its derivatives coding for a hyperfusogenic F protein, or for a cytoplasmic tail-mutated H protein, did not spread. When delivered to primary mouse neurons by cell-mediated neurite overlay, MeV M-F50S frequently reached the cell bodies and occasionally formed small infectious centers, while the other MeV reached the cell bodies only sporadically. These results demonstrate that, in neuronal cell cultures, M-F50S can enable receptor-independent spread in the absence of other mutations, and validate the inference that this single amino acid change initiated ubiquitous MeV brain spread.IMPORTANCEMeasles virus (MeV), a non-integrating negative-strand RNA virus, rarely causes subacute sclerosing panencephalitis (SSPE) several years after acute infection. During brain adaptation, the MeV genome acquires multiple mutations reducing the dependence of its membrane fusion apparatus (MFA) from an activating receptor. It was proposed that one of these mutations, matrix protein F50S, drove neuropathogenesis in an SSPE case. We report here that, in two types of neuronal cultures, a recombinant MeV with only this mutation gained receptor-independent spread, whereas viruses expressing MFA proteins with other mutations acquired during brain adaptation did not. Our results validate the inference that M-F50S initiated ubiquitous MeV brain spread resulting in lethal disease. They also prompt studies of the impact of analogous amino acid changes of the M proteins of other nonsegmented negative-strand RNA viruses on their interactions with membrane lipids and cytoskeletal components.

In 2018, the Navi Mumbai Municipal Corporation implemented phase 1 of a public sector typhoid conjugate vaccine campaign in Navi Mumbai, India, targeting all children aged 9 months to 14 years within its administrative boundaries. To assess associations with receipt of vaccine in phase 1, we used generalized estimating equations to calculate estimates of vaccination by child-, household-, and community-level demographics (child education and age; household head education, income, and occupation; community informal settlement percent). Campaign vaccine receipt was most associated with children enrolled in school (odds ratio [OR] = 3.84, 95% CI: 2.18-6.77), the lowest household income tertile when divided into three equal parts (OR = 1.64, 95% CI: 1.43-1.84), and lower community-level socioeconomic status (OR = 1.06, 95% CI: 1.04-1.08 per 10% informal settlement proportion). The campaign was successful in reaching the most underserved populations of its target communities.

Typbar-TCV®, a typhoid conjugate vaccine (TCV), was prequalified by the World Health Organization in 2017. We evaluated its effectiveness in a mass vaccination program targeting children 9 months to 14 years in Navi Mumbai, India, from September 2018 to July 2020. We compared laboratory-confirmed typhoid cases from six clinical sites with age-matched community controls. Of 38 cases, three (8.6%) received TCV through the campaign, compared with 53 (37%) of 140 controls. The adjusted odds ratio of typhoid fever among vaccinated children was 0.16 (95% CI: 0.05-0.55), equivalent to a vaccine effectiveness of 83.7% (95% CI: 45.0-95.3). Vaccine effectiveness of Typbar-TCV in this large public sector vaccine introduction was similar to prior randomized controlled trials, providing reassurance to policymakers that TCV effectiveness is robust in a large-scale implementation.

We describe humoral immune responses in 105 ambulatory patients with laboratory-confirmed SARS-CoV-2 Omicron variant infection. In dried blood spot (DBS) collected within 5 days of illness onset and during convalescence, we measured binding antibody (bAb) against ancestral spike protein receptor binding domain (RBD) and nucleocapsid (N) protein using a commercial multiplex bead assay. Geometric mean bAb concentrations against RBD increased by a factor of 2.5 from 1258 to 3189 units/mL and by a factor of 47 against N protein from 5.5 to 259 units/mL between acute illness and convalescence; lower concentrations were associated with greater geometric mean ratios. Paired DBS specimens may be used to evaluate humoral response to SARS-CoV-2 infection.

As public health laboratories expand their genomic sequencing and bioinformatics capacity for the surveillance of different pathogens, labs must carry out robust validation, training, and optimization of wet- and dry-lab procedures. Achieving these goals for algorithms, pipelines and instruments often requires that lower quality datasets be made available for analysis and comparison alongside those of higher quality. This range of data quality in reference sets can complicate the sharing of sub-optimal datasets that are vital for the community and for the reproducibility of assays. Sharing of useful, but sub-optimal datasets requires careful annotation and documentation of known issues to enable appropriate interpretation, avoid being mistaken for better quality information, and for these data (and their derivatives) to be easily identifiable in repositories. Unfortunately, there are currently no standardized attributes or mechanisms for tagging poor-quality datasets, or datasets generated for a specific purpose, to maximize their utility, searchability, accessibility and reuse. The Public Health Alliance for Genomic Epidemiology (PHA4GE) is an international community of scientists from public health, industry and academia focused on improving the reproducibility, interoperability, portability, and openness of public health bioinformatic software, skills, tools and data. To address the challenges of sharing lower quality datasets, PHA4GE has developed a set of standardized contextual data tags, namely fields and terms, that can be included in public repository submissions as a means of flagging pathogen sequence data with known quality issues, increasing their discoverability. The contextual data tags were developed through consultations with the community including input from the International Nucleotide Sequence Data Collaboration (INSDC), and have been standardized using ontologies - community-based resources for defining the tag properties and the relationships between them. The standardized tags are agnostic to the organism and the sequencing technique used and thus can be applied to data generated from any pathogen using an array of sequencing techniques. The tags can also be applied to synthetic (lab created) data. The list of standardized tags is maintained by PHA4GE and can be found at https://github.com/pha4ge/contextual_data_QC_tags. Definitions, ontology IDs, examples of use, as well as a JSON representation, are provided. The PHA4GE QC tags were tested, and are now implemented, by the FDA's GenomeTrakr laboratory network as part of its routine submission process for SARS-CoV-2 wastewater surveillance. We hope that these simple, standardized tags will help improve communication regarding quality control in public repositories, in addition to making datasets of variable quality more easily identifiable. Suggestions for additional tags can be submitted to PHA4GE via the New Term Request Form in the GitHub repository. By providing a mechanism for feedback and suggestions, we also expect that the tags will evolve with the needs of the community.

SARS-CoV-2 serosurveys help estimate the extent of transmission and guide the allocation of COVID-19 vaccines. We measured SARS-CoV-2 seroprevalence among women attending ANC clinics to assess exposure trends over time in Zambia. We conducted repeated cross-sectional SARS-CoV-2 seroprevalence surveys among pregnant women aged 15-49 years attending their first ANC visits in four districts of Zambia (two urban and two rural) during September 2021-September 2022. Serologic testing was done using a multiplex bead assay which detects IgG antibodies to the nucleocapsid protein and the spike protein receptor-binding domain (RBD). We calculated monthly SARS-CoV-2 seroprevalence by district. We also categorized seropositive results as infection alone, infection and vaccination, or vaccination alone based on anti-RBD and anti-nucleocapsid test results and self-reported COVID-19 vaccination status (vaccinated was having received ≥1 dose). Among 8,304 participants, 5,296 (63.8%) were cumulatively seropositive for SARS-CoV-2 antibodies from September 2021 through September 2022. SARS-CoV-2 seroprevalence primarily increased from September 2021 to September 2022 in three districts (Lusaka: 61.8-100.0%, Chongwe: 39.6-94.7%, Chipata: 56.5-95.0%), but in Chadiza, seroprevalence increased from 27.8% in September 2021 to 77.2% in April 2022 before gradually dropping to 56.6% in July 2022. Among 5,906 participants with a valid COVID-19 vaccination status, infection alone accounted for antibody responses in 77.7% (4,590) of participants. Most women attending ANC had evidence of prior SARS-CoV-2 infection and most SARS-CoV-2 seropositivity was infection-induced. Capturing COVID-19 vaccination status and using a multiplex bead assay with anti-nucleocapsid and anti-RBD targets facilitated distinguishing infection-induced versus vaccine-induced antibody responses during a period of increasing COVID-19 vaccine coverage in Zambia. Declining seroprevalence in Chadiza may indicate waning antibodies and a need for booster vaccines. ANC clinics have a potential role in ongoing SARS-CoV-2 serosurveillance and can continue to provide insights into SARS-CoV-2 antibody dynamics to inform near real-time public health responses.

Many SARS-CoV-2 infections are asymptomatic, thus reported cases underestimate actual cases. To improve estimates, we conducted surveillance for SARS-CoV-2 seroprevalence among pregnant women attending their first antenatal care visit (ANC1) from June 2021 through May 2022. We administered a questionnaire to collect demographic, risk factors, and COVID-19 vaccine status information and tested dried blood spots for SARS-CoV-2 antibodies. Although <1% of ANC1 participants reported having had COVID-19, monthly SARS-CoV-2 seroprevalence increased from 15.4% (95% CI: 10.5-21.5) in June 2021 to 65.5% (95% CI: 55.5-73.7) in May 2022. Although COVID-19 vaccination was available in March 2021, uptake remained low, reaching a maximum of 9.5% (95% CI: 5.7-14.8) in May 2022. Results of ANC1 serosurveillance provided prevalence estimates helpful in understanding this population case burden that was available through self-report and national case reports. To improve vaccine uptake, efforts to address fears and misconceptions regarding COVID-19 vaccines are needed.

BACKGROUND: Tuberculosis (TB) incidence rates in the Republic of the Marshall Islands are among the highest in the world, 480/100,000 in 2017. In response, the Health Ministry completed islandwide screening in Ebeye Island in 2017. METHODS: Participants were interviewed to obtain TB history, exposures, and symptoms. TB assessment included chest radiography with sputum collection for GeneXpert® MTB-RIF if indicated. TB diagnosis was made by consensus of visiting TB experts. Participants were also screened for Hansen's disease (HD) and diabetes mellitus (DM). For persons aged ≥21 years, blood pressure, cholesterol, and blood glucose were assessed. RESULTS: A total of 5,166 persons (90.0 % of target population) completed screening leading to the identification of 39 new cases of TB (755/100,000) and 14 persons with HD (270/100,000). DM was detected in 1,096 persons (27 %), including in 351 persons not previously diagnosed. The rate of hypertension was 61 % and of hypercholesterolemia was 15 %. New or prevalent TB diagnosis was associated with newly diagnosed or history of DM (aOR 4.68, 2.15-10.20). CONCLUSIONS: In Ebeye, an integrated TB screening campaign found TB, HD, DM, and hypertension. TB and DM were strongly associated.

It is increasingly appreciated that pathogens can spread as infectious units constituted by multiple, genetically diverse genomes, also called collective infectious units or genome collectives. However, genetic characterization of the spatial dynamics of collective infectious units in animal hosts is demanding, and it is rarely feasible in humans. Measles virus (MeV), whose spread in lymphatic tissues and airway epithelia relies on collective infectious units, can, in rare cases, cause subacute sclerosing panencephalitis (SSPE), a lethal human brain disease. In different SSPE cases, MeV acquisition of brain tropism has been attributed to mutations affecting either the fusion or the matrix protein, or both, but the overarching mechanism driving brain adaptation is not understood. Here we analyzed MeV RNA from several spatially distinct brain regions of an individual who succumbed to SSPE. Surprisingly, we identified two major MeV genome subpopulations present at variable frequencies in all 15 brain specimens examined. Both genome types accumulated mutations like those shown to favor receptor-independent cell-cell spread in other SSPE cases. Most infected cells carried both genome types, suggesting the possibility of genetic complementation. We cannot definitively chart the history of the spread of this virus in the brain, but several observations suggest that mutant genomes generated in the frontal cortex moved outwards as a collective and diversified. During diversification, mutations affecting the cytoplasmic tails of both viral envelope proteins emerged and fluctuated in frequency across genetic backgrounds, suggesting convergent and potentially frequency-dependent evolution for modulation of fusogenicity. We propose that a collective infectious unit drove MeV pathogenesis in this brain. Re-examination of published data suggests that similar processes may have occurred in other SSPE cases. Our studies provide a primer for analyses of the evolution of collective infectious units of other pathogens that cause lethal disease in humans.

We performed whole-genome sequencing of 174 Salmonella Typhi and 54 Salmonella Paratyphi A isolates collected through prospective surveillance in the context of a phased typhoid conjugate vaccine introduction in Navi Mumbai, India. We investigate the temporal and geographical patterns of emergence and spread of antimicrobial resistance. We evaluated the relationship between the spatial distance between households and genetic clustering of isolates. Most isolates were non-susceptible to fluoroquinolones, with nearly 20% containing ≥3 quinolone resistance-determining region mutations. Two H58 isolates carried an IncX3 plasmid containing bla(SHV-12), associated with ceftriaxone resistance, suggesting that the ceftriaxone-resistant isolates from India independently evolved on multiple occasions. Among S. Typhi, we identified two main clades circulating (2.2 and 4.3.1 [H58]); 2.2 isolates were closely related following a single introduction around 2007, whereas H58 isolates had been introduced multiple times to the city. Increasing geographic distance between isolates was strongly associated with genetic clustering (odds ratio [OR] = 0.72 per km; 95% credible interval [CrI]: 0.66-0.79). This effect was seen for distances up to 5 km (OR = 0.65 per km; 95% CrI: 0.59-0.73) but not seen for distances beyond 5 km (OR = 1.02 per km; 95% CrI: 0.83-1.26). There was a non-significant reduction in odds of clustering for pairs of isolates in vaccination communities compared with non-vaccination communities or mixed pairs compared with non-vaccination communities. Our findings indicate that S. Typhi was repeatedly introduced into Navi Mumbai and then spread locally, with strong evidence of spatial genetic clustering. In addition to vaccination, local interventions to improve water and sanitation will be critical to interrupt transmission. IMPORTANCE Enteric fever remains a major public health concern in many low- and middle-income countries, as antimicrobial resistance (AMR) continues to emerge. Geographical patterns of typhoidal Salmonella spread, critical to monitoring AMR and planning interventions, are poorly understood. We performed whole-genome sequencing of S. Typhi and S. Paratyphi A isolates collected in Navi Mumbai, India before and after a typhoid conjugate vaccine introduction. From timed phylogenies, we found two dominant circulating lineages of S. Typhi in Navi Mumbai-lineage 2.2, which expanded following a single introduction a decade prior, and 4.3.1 (H58), which had been introduced repeatedly from other parts of India, frequently containing "triple mutations" conferring high-level ciprofloxacin resistance. Using Bayesian hierarchical statistical models, we found that spatial distance between cases was strongly associated with genetic clustering at a fine scale (<5 km). Together, these findings suggest that antimicrobial-resistant S. Typhi frequently flows between cities and then spreads highly locally, which may inform surveillance and prevention strategies.

This Research Topic has focused on subjects such as tracking emerging SARS-CoV-2 variants, detection, isolation, and genomic characterization of emerging variants, transmission, pathogenesis, clinical effects of variants, assessment of COVID-19 vaccination and treatment effectiveness, comparative analysis of SARS-CoV-2 genomic data, and other public health intervention measures. The Research Topic featured 27 articles highlighting the emergence of Omicron variants and their sub-lineages across the globe and their clinical presentations, specifically asymptomatic infections, COVID-19-associated liver injury, and comorbidities such as hypertension, diabetes, and bronchitis. Additionally, a few studies have reported the efficacy of therapeutic drugs in reducing viral load and the significance of vaccination and a booster dose against Omicron variants. Furthermore, the studies on genomic surveillance and evolutionary analysis have demonstrated the emergence of Omicron and its sub-lineages and their characteristic mutations. All these in-depth studies have explored various elements of Omicron, resulting in a comprehensive understanding of this variant.

Background: We estimated combined protection conferred by prior SARS-CoV-2 infection and COVID-19 vaccination against COVID-19-associated acute respiratory illness (ARI). Method(s): During SARS-CoV-2 Delta (B.1.617.2) and Omicron (B.1.1.529) variant circulation between October 2021 and April 2022, prospectively enrolled adult patients with outpatient ARI had respiratory and filter paper blood specimens collected for SARS-CoV-2 molecular testing and serology. Dried blood spots were tested for immunoglobulin-G antibodies against SARSCoV-2 nucleocapsid (NP) and spike protein receptor binding domain antigen using a validated multiplex bead assay. Evidence of prior SARS-CoV-2 infection also included documented or self-reported laboratory-confirmed COVID-19. We used documented COVID-19 vaccination status to estimate vaccine effectiveness (VE) by multivariable logistic regression by prior infection status. Result(s): 455 (29%) of 1577 participants tested positive for SARS-CoV-2 infection at enrollment; 209 (46%) case-patients and 637 (57%) test-negative patients were NP seropositive, had documented previous laboratory-confirmed COVID-19, or self-reported prior infection. Among previously uninfected patients, three-dose VE was 97% (95% confidence interval [CI], 60%-99%) against Delta, but not statistically significant against Omicron. Among previously infected patients, three-dose VE was 57% (CI, 20%-76%) against Omicron; VE against Delta could not be estimated. Conclusion(s): Three mRNA COVID-19 vaccine doses provided additional protection against SARS-CoV-2 Omicron variant-associated illness among previously infected participants. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available for use under a CC0 license.

Abstract We aimed to estimate the household secondary infection attack rate (hSAR) of SARS-CoV-2 in investigations aligned with the WHO Unity Studies Household Transmission Investigations (HHTI) protocol. We conducted a systematic review and meta-analysis according to PRISMA 2020 guidelines. We searched Medline, Embase, Web of Science, Scopus and medRxiv/bioRxiv for “Unity-aligned” First Few X cases (FFX) and HHTIs published 1 December 2019 to 26 July 2021. Standardised early results were shared by WHO Unity Studies collaborators (to 1 October 2021). We used a bespoke tool to assess investigation methodological quality. Values for hSAR and 95% confidence intervals (CIs) were extracted or calculated from crude data. Heterogeneity was assessed by visually inspecting overlap of CIs on forest plots and quantified in meta-analyses. Of 9988 records retrieved, 80 articles (64 from databases; 16 provided by Unity Studies collaborators) were retained in the systematic review; 62 were included in the primary meta-analysis. hSAR point estimates ranged from 2% to 90% (95% prediction interval: 3%–71%; I2 = 99.7%); I2 values remained >99% in subgroup analyses, indicating high, unexplained heterogeneity and leading to a decision not to report pooled hSAR estimates. FFX and HHTI remain critical epidemiological tools for early and ongoing characterisation of novel infectious pathogens. The large, unexplained variance in hSAR estimates emphasises the need to further support standardisation in planning, conduct and analysis, and for clear and comprehensive reporting of FFX and HHTIs in time and place, to guide evidence-based pandemic preparedness and response efforts for SARS-CoV-2, influenza and future novel respiratory viruses.

We aimed to estimate the household secondary infection attack rate (hSAR) of SARS-CoV-2 in investigations aligned with the WHO Unity Studies Household Transmission Investigations (HHTI) protocol. We conducted a systematic review and meta-analysis according to PRISMA 2020 guidelines. We searched Medline, Embase, Web of Science, Scopus and medRxiv/bioRxiv for 'Unity-aligned' First Few X cases (FFX) and HHTIs published between 1 December 2019 and 26 July 2021. Standardised early results were shared by WHO Unity Studies collaborators (to 1 October 2021). We used a bespoke tool to assess investigation methodological quality. Values for hSAR and 95% confidence intervals (CIs) were extracted or calculated from crude data. Heterogeneity was assessed by visually inspecting overlap of CIs on forest plots and quantified in meta-analyses. Of 9988 records retrieved, 80 articles (64 from databases; 16 provided by Unity Studies collaborators) were retained in the systematic review and 62 were included in the primary meta-analysis. hSAR point estimates ranged from 2%-90% (95% prediction interval: 3%-71%; I2=99.7%); I2 values remained >99% in subgroup analyses, indicating high, unexplained heterogeneity and leading to a decision not to report pooled hSAR estimates. FFX and HHTI remain critical epidemiological tools for early and ongoing characterisation of novel infectious pathogens. The large, unexplained variance in hSAR estimates emphasises the need to further support standardisation in planning, conduct and analysis, and for clear and comprehensive reporting of FFX and HHTIs in time and place, to guide evidence-based pandemic preparedness and response efforts for SARS-CoV-2, influenza and future novel respiratory viruses. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY 4.0 International license.

BACKGROUND: We estimated combined protection conferred by prior SARS-CoV-2 infection and COVID-19 vaccination against COVID-19-associated acute respiratory illness (ARI). METHODS: During SARS-CoV-2 Delta (B.1.617.2) and Omicron (B.1.1.529) variant circulation between October 2021 and April 2022, prospectively enrolled adult patients with outpatient ARI had respiratory and filter paper blood specimens collected for SARS-CoV-2 molecular testing and serology. Dried blood spots were tested for immunoglobulin-G antibodies against SARS-CoV-2 nucleocapsid (NP) and spike protein receptor binding domain antigen using a validated multiplex bead assay. Evidence of prior SARS-CoV-2 infection also included documented or self-reported laboratory-confirmed COVID-19. We used documented COVID-19 vaccination status to estimate vaccine effectiveness (VE) by multivariable logistic regression by prior infection status. RESULTS: Four hundred fifty-five (29%) of 1577 participants tested positive for SARS-CoV-2 infection at enrollment; 209 (46%) case-patients and 637 (57%) test-negative patients were NP seropositive, had documented previous laboratory-confirmed COVID-19, or self-reported prior infection. Among previously uninfected patients, three-dose VE was 97% (95% confidence interval [CI], 60%-99%) against Delta, but not statistically significant against Omicron. Among previously infected patients, three-dose VE was 57% (CI, 20%-76%) against Omicron; VE against Delta could not be estimated. CONCLUSIONS: Three mRNA COVID-19 vaccine doses provided additional protection against SARS-CoV-2 Omicron variant-associated illness among previously infected participants.

Acute encephalopathy syndrome (AES) is characterized by sudden onset of seizures and altered sensorium of infectious or non-infectious origin. Seasonal outbreaks of fatal hypoglycaemic AES in children, associated with eating fruit from the Sapindaceae family (e.g., ackee, litchi), have been reported globally [1,2]. Since 1995, AES outbreaks have been reported during the litchi-harvesting season from May–July in Muzaffarpur, the largest commercial litchi-producing district of Bihar, India [3]. An AES outbreak investigation in Muzaffarpur in 2014 linked known toxins hypoglycin A and α-methylene cyclopropyl glycine (MCPG) in litchi fruit to hypoglycaemic AES in children [3]. Following the 2014 outbreak, the Government of Bihar implemented community-based interventions to prevent hypoglycemia in children. They also strengthened the clinical management of hypoglycaemic seizures in public health facilities [4]. The number of AES cases and deaths declined from 2015–18, suggesting that the interventions were effective. However, in May–June 2019, AES cases increased. We conducted a descriptive epidemiological analysis of the AES cases. | | Methods | | We identified AES cases from established hospital-based surveillance in the two tertiary referral hospitals in Muzaffarpur. We defined a suspected AES case as seizures or altered sensorium in a child aged ≤15 years admitted from 1 May to 2nd July 2019. We excluded patients aged six months to 6 years who were admitted for fever and a single generalized convulsion of <15 minutes in duration and recovered consciousness within 60 minutes of seizure. We conducted a review of medical records and abstracted data using a structured tool for socio-demographics, clinical history, duration of hospitalization, treatment, and laboratory profile. We also assembled a prospective cohort of probable cases admitted to the hospital during the investigation. We defined a probable AES case as new-onset seizures or altered sensorium of <7 days duration in a child aged ≤15 years admitted t from 1 May to 2 July 2019. For the cohort of probable cases, we interviewed the caregivers using a structured clinical-epidemiological questionnaire for socio-demographics, anthropometry, illness characteristics, treatment-seeking behavior, meal assessment, exposure to litchi fruit, and exposure to health messages. For anthropometry, we calculated Z-scores using the World Health Organization 2006 standardized growth tables [5]. | | Results | | Of the 655 suspected and probable AES cases identified, the case fatality rate (CFR) was 21% (139 deaths). The median age was four years (interquartile range: 3 months–14 years), and 58% (378) were females. The first case was reported on 5 May 2019, cases peaked on 15 June, and the last case on 2 July (Figure 1). Among cases with available data, 75% (389/518) had blood glucose levels of <70 mg/dL upon hospital admission, and 75% (476/638) were residents of Muzaffarpur district. We identified cases from 15 (94%) of 16 blocks in the Muzaffarpur district and calculated a district incidence of 22 per 100,000 children ≤15 years old. | | The prospective cohort comprised 94 probable AES cases; CFR was 26%. Among probable cases, 63% (49/78) of caregivers were wage workers, and 34% (31/91) were of low socioeconomic status. Symptoms were reported in the early morning (3 am to 8 am) for 67% (62/93) of cases, and 97% (90/93) presented with seizures. Among probable cases with anthropometry data, 62% (43/69) were underweight (i.e., weight-for-age Z score <-2), 44% (25/57) stunted (i.e., height-for-age Z score <-2), and 43% (10/23) wasted (i.e., weight-for-height Z score <-2). Primary health facilities referred 46% (43/93) of probable cases to the two tertiary hospitals for admission. Among cases referred, only 30% (13/43) received hypoglycemia and seizure management at the primary health facility. | | Eating litchis in the 24 hours and seven days before illness onset was reported by 57% (54/94) and 87% (59/68) of caregivers, respectively. Skipping any meal and skipping the evening meal in the 24 hours before illness onset was reported by 55% (48/88) and 44% (28/63) of caregivers, respectively. Among probable cases, 45% (27/60) of caregivers reported Government Supplementary Nutrition (GSN) programme enrollment. Sixty percent (50/83) of caregivers said a visit by health workers in the week before illness. Still, only 8% (7/83) reported receiving messages on AES prevention and early treatment by health workers in the past month. | | Conclusions | | The 2019 AES outbreak in Muzaffarpur district, Bihar, occurred among young children with hypoglycemia upon hospital admission and had high associated mortality. Although the Government of Bihar implemented community and clinical measures to prevent AES cases after the 2014 outbreak, a large proportion of the AES cases did not benefit from the prevention measures based on our investigation [4]. New state and district health leadership, turnover of community and facility-level healthcare workers, lack of ongoing training and focused community outreach, and competing health priorities might have been factors responsible for the resurgence. To prevent future AES cases, we recommended prompt emergency management of hypoglycemia and seizures at primary health facilities before referral. We recommend enrollment of all eligible children to GSN and enhanced community health communications to reinforce the importance of an evening meal for children and limiting the eating of litchi fruit during the harvesting season from May to July

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) originated in Wuhan in December 2019 and rapidly spread across the globe, with the World Health Organization (WHO) declaring it a pandemic in March 2020. Since early 2021, multiple SARS-CoV-2 variants have emerged in various countries around the world (1). Among these, the “Variant of Concern” has been reported to be highly transmissible, infectious, and capable of evading the natural or vaccine-induced immune response. The rapid spread of these variants has resulted in a daily increase in SARS-CoV-2 cases, which are associated with severe morbidity and mortality, exacerbating the pandemic situation (2). The newly emerged variants have become a serious threat to the global COVID-19 vaccination program due to their reduced susceptibility to currently available vaccines (3). It is critical to conduct active genomic surveillance of SARS-CoV-2 variants in order to better understand their transmission, pathogenesis, and the efficacy of vaccines and other therapeutics against these variants.

Background: In December 2020, over 500 residents of Eluru City were hospitalised with seizures and sudden loss of consciousness (LOC) resembling the neurotoxic effects of organochlorine poisoning after a flooding event during the last week of November 2020. We described the epidemiological investigation of outbreak and identified risk factors. Methods: We performed descriptive analysis followed by 1:1 unmatched case-control study. Cases were identified through house-to-house search and review of medical records at district hospital. A case defined as sudden onset LOC or new-onset seizures in an Eluru resident aged ≥1 year, December 1–15, 2020 and a control as absence of neurological symptoms in a person aged ≥1 year selected randomly from same administrative division of the case. We compared cases and controls for possible risk factors and calculated adjusted odds ratio (aOR) with 95% confidence interval (CI). Biological and environmental samples were tested for contaminants. Results: We identified 545 cases (56% males), including one death. Seizures were reported in 491 (90%) cases. Median age was 27 years (interquartile range: 17–37 years) and 480 (88%) cases resided in urban area. Cases were clustered in administrative divisions supplied by municipal water reservoirs. Cases were more likely than controls to use municipal water as primary source of drinking water (aOR = 4.6, 95% CI = 1.6–13.0). High levels (average: 14.6 mg/l) of organochlorine compounds were detected in all municipal water samples (acceptable limit: <0.001 mg/l). Conclusion: This investigation highlights water ingestion as an exposure pathway for environmental contaminants (organochlorines) in the community after largescale flooding. We recommended strengthening safe water surveillance in natural disaster response contingency plans in Eluru. © 2023 The Author(s)

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.

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.

BACKGROUND: The continued spread of insecticide resistance in mosquito vectors of malaria and arboviral diseases may lead to operational failure of insecticide-based interventions if resistance is not monitored and managed efficiently. This study aimed to develop and validate a new WHO glass bottle bioassay method as an alternative to the WHO standard insecticide tube test to monitor mosquito susceptibility to new public health insecticides with particular modes of action, physical properties or both. METHODS: A multi-centre study involving 21 laboratories worldwide generated data on the susceptibility of seven mosquito species (Aedes aegypti, Aedes albopictus, Anopheles gambiae sensu stricto [An. gambiae s.s.], Anopheles funestus, Anopheles stephensi, Anopheles minimus and Anopheles albimanus) to seven public health insecticides in five classes, including pyrethroids (metofluthrin, prallethrin and transfluthrin), neonicotinoids (clothianidin), pyrroles (chlorfenapyr), juvenile hormone mimics (pyriproxyfen) and butenolides (flupyradifurone), in glass bottle assays. The data were analysed using a Bayesian binomial model to determine the concentration-response curves for each insecticide-species combination and to assess the within-bioassay variability in the susceptibility endpoints, namely the concentration that kills 50% and 99% of the test population (LC(50) and LC(99), respectively) and the concentration that inhibits oviposition of the test population by 50% and 99% (OI(50) and OI(99)), to measure mortality and the sterilizing effect, respectively. RESULTS: Overall, about 200,000 mosquitoes were tested with the new bottle bioassay, and LC(50)/LC(99) or OI(50)/OI(99) values were determined for all insecticides. Variation was seen between laboratories in estimates for some mosquito species-insecticide combinations, while other test results were consistent. The variation was generally greater with transfluthrin and flupyradifurone than with the other compounds tested, especially against Anopheles species. Overall, the mean within-bioassay variability in mortality and oviposition inhibition were < 10% for most mosquito species-insecticide combinations. CONCLUSION: Our findings, based on the largest susceptibility dataset ever produced on mosquitoes, showed that the new WHO bottle bioassay is adequate for evaluating mosquito susceptibility to new and promising public health insecticides currently deployed for vector control. The datasets presented in this study have been used recently by the WHO to establish 17 new insecticide discriminating concentrations (DCs) for either Aedes spp. or Anopheles spp. The bottle bioassay and DCs can now be widely used to monitor baseline insecticide susceptibility of wild populations of vectors of malaria and Aedes-borne diseases worldwide.

By 2003, India had started to shift from a high burden of communicable diseases to noncommunicable diseases (NCDs). By 2019, NCDs accounted for two-thirds of all deaths in India (1,2). However, the epidemiologic transition of growth of NCD burden was not uniform among all states. Thus, state-specific policy decisions and program strategies are required to address the growing NCD burden. | | In response to rising NCD prevalence, India launched the National Programme for Prevention and Control of Cancer, Diabetes, Cardiovascular Diseases, and Stroke (NPCDCS) in 2010 to cover all districts in India (3). The program focused on prevention, screening, diagnosis, and management of hypertension, diabetes, cardiovascular disease, and cancer. Program implementation in the states has faced challenges because of a poorly designed monitoring system, interruptions in drug supply, unreliable access to diagnostics, and poor financial planning. A skilled public health workforce at the state and district levels is required to monitor, analyze, and interpret program data to identify key challenges and implement evidence-based strategies to address the challenges (4).

The COVID-19 pandemic caught the world largely unprepared, including scientific and policy communities. On April 10-13, 2022, researchers across academia, industry, government, and nonprofit organizations met at the Keystone symposium "Lessons from the Pandemic: Responding to Emerging Zoonotic Viral Diseases" to discuss the successes and challenges of the COVID-19 pandemic and what lessons can be applied moving forward. Speakers focused on experiences not only from the COVID-19 pandemic but also from outbreaks of other pathogens, including the Ebola virus, Lassa virus, and Nipah virus. A general consensus was that investments made during the COVID-19 pandemic in infrastructure, collaborations, laboratory and manufacturing capacity, diagnostics, clinical trial networks, and regulatory enhancements-notably, in low-to-middle income countries-must be maintained and strengthened to enable quick, concerted responses to future threats, especially to zoonotic pathogens.

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.

BACKGROUND: Studies of thunderstorm asthma to understand risk factors using high-resolution climate data and asthma outcomes on a large scale are scarce. Moreover, thunderstorm asthma is not well studied in the United States. OBJECTIVES: We examined whether climate parameters involved in thunderstorms are associated with emergency department (ED) visits for acute asthma attacks in the United States. METHODS: We analyzed 63,789 asthma-related, daily ED visits for all age groups, and thunderstorm-associated climate data in Louisiana during 2010 through 2012. We performed time-series analyses using quasi-Poisson regression models with natural cubic splines of date, parish, holiday, day of week, season, daily maximum concentrations of ozone (O3) and fine particulate matter [PM 2.5 m in aerodynamic diameter (PM2.5)], and daily mean pressure, precipitation, and temperature. Because of a significant interaction effect between temperature and lightning days on asthma-related visits, we performed stratified analyses by days with/without lightning or thunderstorm (defined by any lightning and precipitation). RESULTS: On thunderstorm days, higher asthma-related ED visits were associated with higher daily mean precipitation [relative risk(RR) =1.145per1g/m2/s (95% CI: 1.009, 1.300)] and lower daily mean temperature [RR =1.011 per 1C change (1.000-1.021)] without carry-over effect to the next non-thunderstorm day. These higher risks were found mainly among children and adults <65years of age. We observed similar results on lightning days. However, we did not find similar associations for non-thunderstorm or non-lightning days. Daily maximum O3 and PM2.5 levels were not significantly associated with asthma ED visits on thunderstorm days. DISCUSSION: Higher precipitation and lower temperature on thunderstorm days appear to contribute to asthma attacks among people with asthma, suggesting they should consider taking precautions during thunderstorms. EDs should consider preparing for a potential increase of asthma-related visits and ensuring sufficient stock of emergency medication and supplies for forecasted severe thunderstorm days. https://doi.org/10.1289/EHP10440.

BACKGROUND: Annual outbreaks of acute encephalitis syndrome pose a major health burden in India. Although Japanese encephalitis virus (JEV) accounts for around 15% of reported cases, the aetiology of most cases remains unknown. We aimed to establish an enhanced surveillance network and to use a standardised diagnostic algorithm to conduct a systematic evaluation of acute encephalitis syndrome in India. METHODS: In this large-scale, systematic surveillance study in India, patients presenting with acute encephalitis syndrome (ie, acute onset of fever with altered mental status, seizure, or both) to any of the 18 participating hospitals across Uttar Pradesh, West Bengal, and Assam were evaluated for JEV (serum and cerebrospinal fluid [CSF] IgM ELISA) per standard of care. In enhanced surveillance, JEV IgM-negative specimens were additionally evaluated for scrub typhus, dengue virus, and West Nile virus by serum IgM ELISA, and for Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, dengue virus, herpes simplex virus, and enterovirus by CSF PCR across five referral laboratories. In 2017, chikungunya and Leptospira serum IgM by ELISA and Zika virus serum and CSF by PCR were also tested. FINDINGS: Of 10107 patients with acute encephalitis syndrome enrolled in enhanced surveillance between Jan 1, 2014, and Dec 31, 2017, 5734 (578%) of 9917 participants with available data were male and 6179 (627%) of 9856 were children aged 15 years and younger. Among patients who provided a sample of either CSF or serum in enhanced surveillance, an aetiology was identified in 1921 (332%) of 5786 patients enrolled between 2014 and 2016 and in 1484 (343%) of 4321 patients enrolled in 2017. The most commonly identified aetiologies were JEV (1023 [177%] of 5786 patients), scrub typhus (645 [185%] of 3489), and dengue virus (161 [52%] of 3124). Among participants who provided both CSF and serum specimens, an aetiology was identified in 1446 (383%) of 3774 patients enrolled between 2014 and 2016 and in 936 (403%) of 2324 enrolled in 2017, representing a 31-times increase in the number of patients with acute encephalitis syndrome with an identified aetiology compared with standard care alone (299 [129%]; p<00001). INTERPRETATION: Implementation of a systematic diagnostic algorithm in an enhanced surveillance platform resulted in a 31-times increase in identification of the aetiology of acute encephalitis syndrome, besides JEV alone, and highlighted the importance of scrub typhus and dengue virus as important infectious aetiologies in India. These findings have prompted revision of the national testing guidelines for this syndrome across India. FUNDING: US Centers for Disease Control and Prevention.

BACKGROUND: Long-lasting insecticide nets (LLINs) are a core malaria intervention. LLINs should retain efficacy against mosquito vectors for a minimum of three years. Efficacy and durability of Olyset(®) Plus, a permethrin and piperonyl butoxide (PBO) treated LLIN, was evaluated versus permethrin treated Olyset(®) Net. In the absence of WHO guidelines of how to evaluate PBO nets, and considering the manufacturer's product claim, Olyset(®) Plus was evaluated as a pyrethroid LLIN. METHODS: This was a household randomized controlled trial in a malaria endemic rice cultivation zone of Kirinyaga County, Kenya between 2014 and 2017. Cone bioassays and tunnel tests were done against Anopheles gambiae Kisumu. The chemical content, fabric integrity and LLIN survivorship were monitored. Comparisons between nets were tested for significance using the Chi-square test. Exact binomial distribution with 95% confidence intervals (95% CI) was used for percentages. The WHO efficacy criteria used were ≥ 95% knockdown and/or ≥ 80% mortality rate in cone bioassays and ≥ 80% mortality and/or ≥ 90% blood-feeding inhibition in tunnel tests. RESULTS: At 36 months, Olyset(®) Plus lost 52% permethrin and 87% PBO content; Olyset(®) Net lost 24% permethrin. Over 80% of Olyset(®) Plus and Olyset(®) Net passed the WHO efficacy criteria for LLINs up to 18 and 12 months, respectively. At month 36, 91.2% Olyset(®) Plus and 86.4% Olyset(®) Net survived, while 72% and 63% developed at least one hole. The proportionate Hole Index (pHI) values representing nets in good, serviceable and torn condition were 49.6%, 27.1% and 23.2%, respectively for Olyset(®) Plus, and 44.9%, 32.8% and 22.2%, respectively for Olyset(®) Net but were not significantly different. CONCLUSIONS: Olyset(®) Plus retained efficacy above or close to the WHO efficacy criteria for about 2 years than Olyset(®) Net (1-1.5 years). Both nets did not meet the 3-year WHO efficacy criteria, and showed little attrition, comparable physical durability and survivorship, with 50% of Olyset(®) Plus having good and serviceable condition after 3 years. Better community education on appropriate use and upkeep of LLINs is essential to ensure effectiveness of LLIN based malaria interventions.

PURPOSE AND OBJECTIVES: A process evaluation, the Uttarakhand Tobacco Free Initiative (UTFI), was conducted in 49 public high schools and colleges in the state of Uttarakhand, India, to measure program implementation, provide feedback to school administrators, and identify barriers to tobacco control. INTERVENTION APPROACH: UTFI aims to 1) raise awareness and provide education and tools for teachers and school administrators about the dangers of tobacco use and secondhand smoke, 2) encourage participation in student-led activities to promote tobacco-free initiatives, and 3) enforce tobacco-free school policies in the state of Uttarakhand. EVALUATION METHODS: We used the CDC evaluation framework to document key components and lessons learned from the UTFI. We distributed questionnaires to 71 teachers and principals in December 2016, to assess awareness of school activities and policies related to the initiative. Descriptive statistics were computed for quantitative data, and a thematic content analysis was used for qualitative data. RESULTS: Of the 71 participants, 66 (92.9%) were aware of tobacco use policies in schools, and 63 (88.7%) agreed policies were enforced. Sixty-six participants (93.0%) said that they taught tobacco prevention-related topics, and 41 of 70 respondents (58.6%) reported that a student-led group helped to enforce tobacco-free policies in their schools. Of 69 respondents, almost all (n = 66) reported satisfaction with UTFI implementation. Challenges identified were related to tobacco products being readily accessible near school premises, lack of tobacco prevention materials, and tobacco use by school staff. IMPLICATIONS FOR PUBLIC HEALTH: Successes of UTFI were documented by measuring different components of the process, including implementation of program activities and teacher and principal satisfaction. Results might help enhance key processes for the initiative and highlight some barriers to implementation, such as enforcing tobacco control policy off school premises. Continued efforts are needed to prevent tobacco use among young people.

BACKGROUND: Mandla District in Madhya Pradesh, India, reported a suspected cholera outbreak from Ghughri subdistrict on August 18, 2016. OBJECTIVE: We investigated to determine risk factors and recommend control and prevention measures. METHODS: We defined a case as >3 loose stools in 24 h in a Ghughri resident between July 20 and August 19, 2016. We identified cases by passive surveillance in health facilities and by a house-to-house survey in 28 highly affected villages. We conducted a 1:2 unmatched case-control study, collected stool samples for culture, and tested water sources for fecal contamination. RESULTS: We identified 628 cases (61% female) from 96 villages; the median age was 27 years (range: 1 month-76 years). Illnesses began 7 days after rainfall with 259 (41%) hospitalizations and 14 (2%) deaths in people from remote villages who died before reaching a health facility; 12 (86%) worked in paddy fields. Illness was associated with drinking well water within paddy fields (odds ratio [OR] = 4.0, 95% confidence interval [CI] = 1.4-8.0) and not washing hands with soap after defecation (OR = 6.1, CI = 1.7-21). Of 34 stool cultures, 11 (34%) tested positive for Vibrio cholerae O1 Ogawa. We observed open defecation in affected villages around paddy fields. Of 16 tested water sources in paddy fields, eight (50%) were protected, but 100% had fecal contamination. CONCLUSION: We recommended education regarding pit latrine sanitation and safe water, especially in paddy fields, provision of oral rehydration solution in remote villages, and chlorine tablets for point-of-use treatment of drinking water.