Modeling undetected poliovirus circulation following the 2022 outbreak in the United States.

BACKGROUND: New York State (NYS) reported a polio case (June 2022) and outbreak of imported type 2 circulating vaccine-derived poliovirus (cVDPV2) (last positive wastewater detection in February 2023), for which uncertainty remains about potential ongoing undetected transmission. RESEARCH DESIGN AND METHODS: Extending a prior deterministic model, we apply an established stochastic modeling approach to characterize the confidence about no circulation (CNC) of cVDPV2 as a function of time since the last detected signal of transmission (i.e. poliovirus positive acute flaccid myelitis case or wastewater sample). RESULTS: With the surveillance coverage for the NYS population majority and its focus on outbreak counties, modeling suggests a high CNC (95%) within 3-10 months of the last positive surveillance signal, depending on surveillance sensitivity and population mixing patterns. Uncertainty about surveillance sensitivity implies longer durations required to achieve higher CNC. CONCLUSIONS: In populations that maintain high overall immunization coverage with inactivated poliovirus vaccine (IPV), rare polio cases may occur in un(der)-vaccinated individuals. Modeling demonstrates the unlikeliness of type 2 outbreaks reestablishing endemic transmission or resulting in large absolute numbers of paralytic cases. Achieving and maintaining high immunization coverage with IPV remains the most effective measure to prevent outbreaks and shorten the duration of imported poliovirus transmission.

Modeling Poliovirus Transmission and Responses in New York State.

BACKGROUND: In July 2022, New York State (NYS) reported a case of paralytic polio in an unvaccinated young adult, and subsequent wastewater surveillance confirmed sustained local transmission of type 2 vaccine-derived poliovirus (VDPV2) in NYS with genetic linkage to the paralyzed patient. METHODS: We adapted an established poliovirus transmission and oral poliovirus vaccine evolution model to characterize dynamics of poliovirus transmission in NYS, including consideration of the immunization activities performed as part of the declared state of emergency. RESULTS: Despite sustained transmission of imported VDPV2 in NYS involving potentially thousands of individuals (depending on seasonality, population structure, and mixing assumptions) in 2022, the expected number of additional paralytic cases in years 2023 and beyond is small (less than 0.5). However, continued transmission and/or reintroduction of poliovirus into NYS and other populations remains a possible risk in communities that do not achieve and maintain high immunization coverage. CONCLUSIONS: In countries such as the United States that use only inactivated poliovirus vaccine, even with high average immunization coverage, imported polioviruses may circulate and pose a small but nonzero risk of causing paralysis in nonimmune individuals.

Consequences of Undervaccination - Measles Outbreak, New York City, 2018-2019.

BACKGROUND: Measles was declared eliminated in the United States in 2000, but the risk of outbreaks owing to international importations remains. An outbreak of measles in New York City began when one unvaccinated child returned home from Israel with measles; onset of rash occurred on September 30, 2018, 9 days after the child returned home. METHODS: We investigated suspected cases of measles by conducting interviews, reviewing medical and immunization records, identifying exposed persons, and performing diagnostic testing. Measles-mumps-rubella (MMR) vaccine (given as either MMR or measles-mumps-rubella-varicella vaccine and collectively referred to as MMR vaccine) uptake was monitored with the use of the Citywide Immunization Registry. The total direct cost to the New York City Department of Health and Mental Hygiene was calculated. RESULTS: A total of 649 cases of measles were confirmed, with onsets of rash occurring between September 30, 2018, and July 15, 2019. A majority of the patients (93.4%) were part of the Orthodox Jewish community, and 473 of the patients (72.9%) resided in the Williamsburg area of Brooklyn, New York. The median age was 3 years; 81.2% of the patients were 18 years of age or younger, and 85.8% of the patients with a known vaccination history were unvaccinated. Serious complications included pneumonia (in 37 patients [5.7%]) and hospitalization (in 49 patients [7.6%]); among the patients who were hospitalized, 20 (40.8%) were admitted to an intensive care unit. As a result of efforts to promote vaccination, the percentage of children in Williamsburg who received at least one dose of MMR vaccine increased from 79.5% to 91.1% among children 12 to 59 months of age. As of September 9, 2019, a total of 559 staff members at the Department of Health and Mental Hygiene (7% of the agency) had been involved in the measles response. The cost of the Department of Health and Mental Hygiene response was $8.4 million. CONCLUSIONS: Importation of measles and vaccination delays among young children led to an outbreak of measles in New York City. The outbreak response was resource intensive and caused serious illness, particularly among unvaccinated children.

Can a gastric cancer risk survey identify high-risk patients for endoscopic screening? A pilot study.

BACKGROUND: A questionnaire that distinguishes how variability in gastric cancer prevalence is associated with ethnicity/birth country/immigration/cultural diet along with known risk factors may improve targeting populations for gastric cancer screening in the United States. METHODS: Existing literature was used to identify the item pool. Cluster analysis, focus groups, and cognitive interviewing were used to reduce collinear items and refine the questionnaire. Logistic regression analysis was used to determine which items distinguished gastric cancer cases from the primary care and community controls. RESULTS: The results of analysis of data from 40 cases and 100 controls (primary care = 47; community = 53) were used to reduce the 227 item pool to 12 items. After ranking these variables using model bootstrapping, a logistic regression model using the highest ranked eight variables was chosen as the final model. Older age, foreign nativity, daily consumption of cultural food at ages 15-18, less than high-school education, and greater acculturation were significantly associated with being a gastric cancer case compared with the controls. CONCLUSIONS: An eight-item survey that addresses gastric cancer risk factors, ethnicity, cultural habits, and immigration patterns has potential to identify high-risk persons from multicultural areas within the US, who might benefit from endoscopic screening for gastric cancer.

The newly proposed clinical and post-neoadjuvant treatment staging classifications for gastric adenocarcinoma for the American Joint Committee on Cancer (AJCC) staging.

PURPOSE: New stage grouping classifications for clinical (cStage) and post-neoadjuvant treatment (ypStage) stage for gastric adenocarcinoma have been proposed for the eighth edition of the AJCC manual. This article summarizes the analysis for these stages. METHODS: Gastric adenocarcinoma patients diagnosed in 2004-2009 were identified from the National Cancer Database (NCDB). The cStage cohort included both surgical and nonsurgical cases, and the ypStage cohort included only patients who had chemotherapy or radiation therapy before surgery. Survival differences between the stage groups were determined by the log-rank test and prognostic accuracy was assessed by concordance index. Analysis was performed using SAS 9.4 (SAS, Cary, NC, USA). RESULTS: Five strata for cStage and four strata for ypStage were developed. The 5-year survival rates for cStages were 56.77%, 47.39%, 33.1%, 25.9%, and 5.0% for stages I, IIa, IIb, III, and IV, respectively, and the rates for ypStage were 74.2%, 46.3%, 19.2%, and 11.6% for stages I, II, III, and IV, respectively. The log-rank test showed that survival differences were well stratified and stage groupings were ordered and distinct (p < 0.0001). The proposed cStage and ypStage classification was sensitive and specific and had high prognostic accuracy (cStage: c index = 0.81, 95% CI, 0.79-0.83; ypStage: c index = 0.80, 95% CI, 0.73-0.87). CONCLUSION: The proposed eighth edition establishes two new staging schemata that provide essential prognostic data for patients before treatment and for patients who have undergone surgery following neoadjuvant therapy. These additions are a significant advance to the AJCC staging manual and will provide critical guidance to clinicians in making informed decisions throughout the treatment course.