The transmission of Bordetella pertussis to young infants: identifying close and casual contact sources

Background: Pertussis is increasingly recognized as a public health concern among infants too young to be vaccinated despite widespread vaccination. Valid estimates of who infects young infants with Bordetella pertussis are unavailable because previous studies did not identify source cases for 47% to 60% of infant cases. Furthermore, the proportion of transmission due to casual contact among those with unidentified sources remains unknown. Methods: A prospective multi-center study was conducted of laboratory confirmed infant pertussis cases (aged ? 6 months) and their close contacts in France, Germany, the U.S. and Canada from February 2003 through September 2004. A comprehensive diagnostic evaluation was performed on all participants independent of symptoms. Complete case and multiple imputation (MI) analyses were used to address missing data among participants and non-participants. Source cases were identified and described by relationship to the infant, age, and household status. Results: The study population comprised 95 index cases and 460 contacts. The source of pertussis was identified for 66% and 69% of infants using MI and the complete case analysis, respectively. In the primary analysis, parents accounted for 55% of source cases, followed by siblings (16%), aunts/uncles (10%), friends/cousins (10%), grandparents (6%), and part-time caretakers (2%). The estimated distribution of source cases with close contact was robust to changes in the source case definition in sensitivity analyses. However, the proportion of transmission due to casual community contact was sensitive to changes in the incubation and infectious periods used in the source case definition, and sensitive to allowing transmission from those with asymptomatic laboratory confirmed infection, resulting in estimates ranging from 20% to 48%. Discussion: This study provides evidence that among infants for whom a source case was identified, household members were responsible for 76% to 83% of transmission of B. pertussis to this high-risk group. Also, transmission from casual community contact accounts for an appreciable proportion of transmission to young infants. Vaccinating adolescents and adults with close contact to infants may be an important strategy in reducing the incidence of infant pertussis if high coverage rates can be achieved

Factors Associated with Medication Adherence Among a High-Risk Hepatitis C Birth Cohort

BACKGROUND: Multiple studies of hepatitis C virus (HCV) reported that 75% of individuals infected with HCV were born between 1945-1965 and were previously never tested. Therefore, in 2012 the CDC published recommendations that all individuals in this birth cohort should be screened for HCV at least once. Adherence to treatment is essential to achieve a sustained virologic response (SVR) for HCV cure. Patients who do not complete the treatment are at risk of treatment failure. The Adherence to Refills and Medication Scale (ARMS) has been an effective tool for predicting adherence of medication treatment in cardiovascular disease and diabetes and identifying risk factors associated with nonadherence to treatment for these diseases. The purpose of this study is to elucidate which risk factors significantly influence the ARMS score among this birth cohort at risk for HCV to guide future HCV treatment protocol adherence. METHODS: This study recruited patients born between 1945-1965 and accessing care at the OU Physicians-Tulsa Family Medicine clinic between March-July 2019. Data was collected using a prescreening survey consisting of demographics, questions related to HCV risk factors (blood transfusions, tattoos, and intravenous drug use), depression assessed with the PHQ9 tool, and adverse childhood experiences (ACEs). IVDU, ACEs, and PHQ9 were classified into groups. Mean ARMS scores were compared using t-tests for variables with two categories and analysis of variance for variables with three or more categories. All statistical analyses were performed in SAS 9.4. RESULTS: Among the 75 participants in the study, most were women (57%) and the sample had a mean ARMS score of 16.32 (SD=3.45). About half reported depression (51%) and one-third reported four or more ACEs (33%). Mean ARMS scores were 2.983 points (95% CI: 0.70-5.26) higher among those with moderate depression (PHQ 5-14), and 2.699 points (95% CI: 0.65-4.75) higher among those with severe depression (PHQ 15-27) than those with a minimal depression (PHQ 0-4). Similarly, mean ARMS score was 2.61 points (95% CI: 0.34-4.88) higher among those with at least four ACEs compared to those with three ACEs or less. Mean ARMS scores did not differ for any other variables. CONCLUSION: This is the first study to assess the ARMS score as a predictor of medication adherence and risk factors associated with the ARMS score in this high-risk birth cohort for HCV infection. These findings indicate that depression and ACEs may be risk factors for poor medication adherence in this population.N

Spinach-associated Escherichia coli O157:H7 Outbreak, Utah and New Mexico, 2006

In 2006, Utah and New Mexico health departments investigated a multistate cluster of Escherichia coli O157:H7. A case–control study of 22 case-patients found that consuming bagged spinach was significantly associated with illness (p<0.01). The outbreak strain was isolated from 3 bags of 1 brand of spinach. Nationally, 205 persons were ill with the outbreak strain

Estimating the role of casual contact from the community in transmission of Bordetella pertussis to young infants

The proportion of infant pertussis cases due to transmission from casual contact in the community has not been estimated since before the introduction of pertussis vaccines in the 1950s. This study aimed to estimate the proportion of pertussis transmission due to casual contact using demographic and clinical data from a study of 95 infant pertussis cases and their close contacts enrolled at 14 hospitals in France, Germany, Canada, and the U.S. between February 2003 and September 2004. A complete case analysis was conducted as well as multiple imputation (MI) to account for missing data for participants and close contacts who did not participate. By considering all possible close contacts, the MI analysis estimated 66% of source cases were close contacts, implying the minimum attributable proportion of infant cases due to transmission from casual contact with community members was 34% (95% CI = 24%, 44%). Estimates from the complete case analysis were comparable but less precise. Results were sensitive to changes in the operational definition of a source case, which broadened the range of MI point estimates of transmission from casual community contact to 20%–47%. We conclude that casual contact appears to be responsible for a substantial proportion of pertussis transmission to young infants

Immune Boosting Explains Regime-Shifts in Prevaccine-Era Pertussis Dynamics

Understanding the biological mechanisms underlying episodic outbreaks of infectious diseases is one of mathematical epidemiology’s major goals. Historic records are an invaluable source of information in this enterprise. Pertussis (whooping cough) is a re-emerging infection whose intermittent bouts of large multiannual epidemics interspersed between periods of smaller-amplitude cycles remain an enigma. It has been suggested that recent increases in pertussis incidence and shifts in the age-distribution of cases may be due to diminished natural immune boosting. Here we show that a model that incorporates this mechanism can account for a unique set of pre-vaccine-era data from Copenhagen. Under this model, immune boosting induces transient bursts of large amplitude outbreaks. In the face of mass vaccination, the boosting model predicts larger and more frequent outbreaks than do models with permanent or passively-waning immunity. Our results emphasize the importance of understanding the mechanisms responsible for maintaining immune memory fo

The Epidemiology of COVID-19 by Race/Ethnicity in Oklahoma City&ndash;County, Oklahoma (12 March 2020&ndash;31 May 2021)

We aimed to better understand the racially-/ethnically-specific COVID-19-related outcomes, with respect to time, to respond more effectively to emerging variants. Surveillance data from Oklahoma City&ndash;County (12 March 2020&ndash;31 May 2021) were used to summarize COVID-19 cases, hospitalizations, deaths, and COVID-19 vaccination status by racial/ethnic group and ZIP code. We estimated racially-/ethnically-specific daily hospitalization rates, the proportion of cases hospitalized, and disease odds ratios (OR) adjusting for sex, age, and the presence of at least one comorbidity. Hot spot analysis was performed using normalized values of cases, hospitalizations, and deaths generated from incidence rates per 100,000 population. During the study period, there were 103,030 confirmed cases, 3457 COVID-19-related hospitalizations, and 1500 COVID-19-related deaths. The daily 7-day average hospitalization rate for Hispanics peaked earlier than other groups and reached a maximum (3.0/100,000) in July 2020. The proportion of cases hospitalized by race/ethnicity was 6.09% among non-Hispanic Blacks, 5.48% among non-Hispanic Whites, 3.66% among Hispanics, 3.43% among American Indians, and 2.87% among Asian/Pacific Islanders. COVID-19 hot spots were identified in ZIP codes with minority communities. The Hispanic population experienced the first surge in COVID-19 cases and hospitalizations, while non-Hispanic Blacks ultimately bore the highest burden of COVID-19-related hospitalizations and deaths

Is There Less Opioid Abuse in States Where Marijuana Has Been Decriminalized, Either for Medicinal or Recreational Use? A Clin-IQ

Opioid use, abuse, and associated mortality have reached an epidemic level. In some states, cannabis is being used to treat chronic pain. To examine the hypothesis that medical marijuana legislation may reduce adverse opioid-related outcomes if patients substitute cannabis for opioids for pain management, we conducted a clinical inquiry (Clin-IQ). We searched Ovid MEDLINE, Ovid MEDLINE In-Process, and Embase for studies using the search terms marijuana, cannabis, legal, marijuana smoking, medical marijuana, opioid-related disorders, cannabis use, medical cannabis, legal aspect, and opiate addiction. We included population-based articles published from January 1, 2012, through December 5, 2018, that assessed the relationship between marijuana use and decriminalization and the aforementioned opioid-related outcomes. Ten peer-reviewed studies met the inclusion criteria; 3 cross-sectional studies, 6 ecologic studies (ie, using aggregate data), and 1 retrospective cohort study. Eight studies reported associations between policies decriminalizing marijuana and reduced prescription opioid use, 1 study was inconclusive, and the retrospective cohort study reported an increase in adverse opioid-related outcomes. These results should be interpreted with caution given limitations associated with the studies’ design. Results demonstrating association between marijuana decriminalization and opioid-related outcomes are mixed. Longitudinal studies are needed, and further analysis of this policy should continue to be tracked

Inducing Herd Immunity against Seasonal Influenza in Long-Term Care Facilities through Employee Vaccination Coverage: A Transmission Dynamics Model

Introduction. Vaccinating healthcare workers (HCWs) in long-term care facilities (LTCFs) may effectively induce herd immunity and protect residents against influenza-related morbidity and mortality. We used influenza surveillance data from all LTCFs in New Mexico to validate a transmission dynamics model developed to investigate herd immunity induction. Material and Methods. We adjusted a previously published transmission dynamics model and used surveillance data from an active system among 76 LTCFs in New Mexico during 2006-2007 for model validation. We used a deterministic compartmental model with a stochastic component for transmission between residents and HCWs in each facility in order to simulate the random variation expected in such populations. Results. When outbreaks were defined as a dichotomous variable, our model predicted that herd immunity could be induced. When defined as an attack rate, the model demonstrated a curvilinear trend, but insufficiently strong to induce herd immunity. The model was sensitive to changes in the contact parameter β but was robust to changes in the visitor contact probability. Conclusions. These results further elucidate previous studies’ findings that herd immunity may not be induced by vaccinating HCWs in LTCFs; however, increased influenza vaccination coverage among HCWs reduces the probability of influenza infection among residents

Firearm Injury Encounters in the Veterans Health Administration (VHA), 2010-2015

IntroductionFirearm violence is an issue of public health concern leading tomore than 30,000 deaths and 80,000 nonfatal injuries in the UnitedStates annually.1To date, firearm-related studies among Veteranshave focused primarily on suicide and attempted suicide.2-5Herein,we examine firearm violence among VHA enrollees for all manners/intents, including assault, unintentional, self-inflicted, undeterminedand other firearm-related injury encounters in both the inpatient andoutpatient settings.MethodsInpatient and Outpatient encounters with one or more ICD-9-CM firearm external-cause-of-injury codes (E-codes) from1/1/2010-9/30/2015 were extracted from the VHA’s Praedico™Public Health Surveillance System, including demographics, era ofservice/eligibility, encounter type, and deaths. Firearm E-codes wereclassified for manner/intent based on the CDC’s Web-based InjuryStatistics Query and Reporting System (WISQARS™) matrix.6Outpatient/emergency department (ED) data were exclusively fromVHA facilities (a single pediatric patient seen as a humanitarianemergency was excluded from the dataset). Inpatient data includedVHA facilities and some records received from non-VHA facilities.VHA rate of hospitalization for firearm-related admissions wascalculated using the total VHA acute-care admissions for the sametime period as the denominator.ResultsDuring the time frame examined, 5,205 unique individuals wereseen with a firearm E-code. Of these, 4,221 were seen in the outpatient/ED setting only, 597 in the inpatient setting only, and the remaining387 had encounters in both the outpatient/ED and inpatient settings.VHA firearm admission rate was 1.63 per 10,000 VHA admissions,compared to a national rate of 1.96 per 10,000 in 2010.7Table 1 showsthe breakdown of encounters by manner/intent. Unintentional was themost common firearm injury manner/intent. Overall, the median age atinitial encounter was 54 (range 19-100 years), and 96% were male. Thehighest percentage served in the Persian Gulf War Era (2,136, 41%),followed by Vietnam Era (1,816, 35%) and Post-Vietnam Era (716,14%). The greatest number of patients with a firearm-coded encounterresided in Texas (453), California (349), Florida (326), Arizona (214)and Ohio (212).ConclusionsUnintentional injuries were the most common form of firearminjury among VHA enrollees, representing over half of alloutpatient/ED firearm encounters and more than twice the numberof firearm hospitalizations compared with any other manner/intent.Limitations include that not all U.S. Veterans are VHA enrollees;miscoding and misclassification of firearm-related injuries may haveoccurred; and data from non-VHA outpatient/ED encounters andsome non-VHA hospitalizations are not available to our surveillancesystem for analysis. Additional study is needed to further understandthe epidemiology of firearm-related injuries among Veterans andinform VHA leadership and provider