The National Wastewater Surveillance System (NWSS): From inception to widespread coverage, 2020-2022, United States.

Wastewater surveillance is a valuable tool that can be used to track infectious diseases in a community. In September 2020, the Centers for Disease Control and Prevention (CDC) established the National Wastewater Surveillance System (NWSS) to coordinate and build the nation's capacity to detect and quantify concentrations of SARS-CoV-2 RNA in U.S. wastewater. This is the first surveillance summary of NWSS, covering September 1, 2020 to December 31, 2022. Through partnerships with state, tribal, local, and territorial health departments, NWSS became a national surveillance platform that can be readily expanded and adapted to meet changing public health needs. Beginning with 209 sampling sites in September 2020, NWSS rapidly expanded to >1500 sites by December 2022, covering ≈47 % of the U.S. population. As of December 2022, >152,000 unique wastewater samples have been collected by NWSS partners, primarily from wastewater treatment plants (WWTPs). WWTPs participating in NWSS tend to be larger than the average U.S. WWTP and serve more populated communities. In December 2022, ≈8 % of the nearly 16,000 U.S. WWTPs were participating in NWSS. NWSS partners used a variety of methods for sampling and testing wastewater samples; however, progress is being made to standardize these methods. In July 2021, NWSS partners started submitting SARS-CoV-2 genome sequencing data to NWSS. In October 2022, NWSS expanded to monkeypox virus testing, with plans to include additional infectious disease targets in the future. Through the rapid implementation and expansion of NWSS, important lessons have been learned. Wastewater surveillance programs should consider both surge and long-term capacities when developing an implementation plan, and early standardization of sampling and testing methods is important to facilitate data comparisons across sites. NWSS has proven to be a flexible and sustainable surveillance system that will continue to be a useful complement to case-based surveillance for guiding public health action.

Expansion of Neisseria meningitidis Serogroup C Clonal Complex 10217 during Meningitis Outbreak, Burkina Faso, 2019.

During January 28-May 5, 2019, a meningitis outbreak caused by Neisseria meningitidis serogroup C (NmC) occurred in Burkina Faso. Demographic and laboratory data for meningitis cases were collected through national case-based surveillance. Cerebrospinal fluid was collected and tested by culture and real-time PCR. Among 301 suspected cases reported in 6 districts, N. meningitidis was the primary pathogen detected; 103 cases were serogroup C and 13 were serogroup X. Whole-genome sequencing revealed that 18 cerebrospinal fluid specimens tested positive for NmC sequence type (ST) 10217 within clonal complex 10217, an ST responsible for large epidemics in Niger and Nigeria. Expansion of NmC ST10217 into Burkina Faso, continued NmC outbreaks in the meningitis belt of Africa since 2019, and ongoing circulation of N. meningitidis serogroup X in the region underscore the urgent need to use multivalent conjugate vaccines in regional mass vaccination campaigns to reduce further spread of those serogroups.

Is detection of enteropathogens and human or animal faecal markers in the environment associated with subsequent child enteric infections and growth: an individual participant data meta-analysis.

BACKGROUND: Quantifying contributions of environmental faecal contamination to child diarrhoea and growth faltering can illuminate causal mechanisms behind modest health benefits in recent water, sanitation, and hygiene (WASH) trials. We aimed to assess associations between environmental detection of enteropathogens and human or animal microbial source tracking markers (MSTM) and subsequent child health outcomes. METHODS: In this individual participant data meta-analysis we searched we searched PubMed, Embase, CAB Direct Global Health, Agricultural and Environmental Science Database, Web of Science, and Scopus for WASH intervention studies with a prospective design and concurrent control that measured enteropathogens or MSTM in environmental samples, or both, and subsequently measured enteric infections, diarrhoea, or height-for-age Z-scores (HAZ) in children younger than 5 years. We excluded studies that only measured faecal indicator bacteria. The initial search was done on Jan 19, 2021, and updated on March 22, 2023. One reviewer (AM) screened abstracts, and two independent reviewers (AM and RT) examined the full texts of short-listed articles. All included studies include at least one author that also contributed as an author to the present Article. Our primary outcomes were the 7-day prevalence of caregiver-reported diarrhoea and HAZ in children. For specific enteropathogens in the environment, primary outcomes also included subsequent child infection with the same pathogen ascertained by stool testing. We estimated associations using covariate-adjusted regressions and pooled estimates across studies. FINDINGS: Data from nine published reports from five interventions studies, which included 8603 children (4302 girls and 4301 boys), were included in the meta-analysis. Environmental pathogen detection was associated with increased infection prevalence with the same pathogen and lower HAZ (ΔHAZ -0·09 [95% CI -0·17 to -0·01]) but not diarrhoea (prevalence ratio 1·22 [95% CI 0·95 to 1·58]), except during wet seasons. Detection of MSTM was not associated with diarrhoea (no pooled estimate) or HAZ (ΔHAZ -0·01 [-0·13 to 0·11] for human markers and ΔHAZ -0·02 [-0·24 to 0·21] for animal markers). Soil, children's hands, and stored drinking water were major transmission pathways. INTERPRETATION: Our findings support a causal chain from pathogens in the environment to infection to growth faltering, indicating that the lack of WASH intervention effects on child growth might stem from insufficient reductions in environmental pathogen prevalence. Studies measuring enteropathogens in the environment should subsequently measure the same pathogens in stool to further examine theories of change between WASH, faecal contamination, and health. Given that environmental pathogen detection was predictive of infection, programmes targeting specific pathogens (eg, vaccinations and elimination efforts) can environmentally monitor the pathogens of interest for population-level surveillance instead of collecting individual biospecimens. FUNDING: The Bill & Melinda Gates Foundation and the UK Foreign and Commonwealth Development Office.

Detecting Mpox Cases Through Wastewater Surveillance - United States, August 2022-May 2023.

In October 2022, CDC's National Wastewater Surveillance System began routine testing of U.S. wastewater for Monkeypox virus. Wastewater surveillance sensitivity, positive predictive value (PPV), and negative predictive value (NPV) for Monkeypox virus were evaluated by comparing wastewater detections (Monkeypox virus detected versus not detected) to numbers of persons with mpox in a county who were shedding virus. Case ascertainment was assumed to be complete, and persons with mpox were assumed to shed virus for 25 days after symptom onset. A total of 281 cases and 3,492 wastewater samples from 89 sites in 26 counties were included in the analysis. Wastewater surveillance in a single week, from samples representing thousands to millions of persons, had a sensitivity of 32% for detecting one or more persons shedding Monkeypox virus, 49% for detecting five or more persons shedding virus, and 77% for detecting 15 or more persons shedding virus. Weekly PPV and NPV for detecting persons shedding Monkeypox virus in a county were 62% and 80%, respectively. An absence of detections in counties with wastewater surveillance signified a high probability that a large number of cases were not present. Results can help to guide the public health response to Monkeypox virus wastewater detections. A single, isolated detection likely warrants a limited public health response. An absence of detections, in combination with no reported cases, can give public health officials greater confidence that no cases are present. Wastewater surveillance can serve as a useful complement to case surveillance for guiding the public health response to an mpox outbreak.