Update of the Blood Lead Reference Value - United States, 2021.

The negative impact of lead exposure on young children and those who become pregnant is well documented but is not well known by those at highest risk from this hazard. Scientific evidence suggests that there is no known safe blood lead level (BLL), because even small amounts of lead can be harmful to a child's developing brain (1). In 2012, CDC introduced the population-based blood lead reference value (BLRV) to identify children exposed to more lead than most other children in the United States. The BLRV should be used as a guide to 1) help determine whether medical or environmental follow-up actions should be initiated for an individual child and 2) prioritize communities with the most need for primary prevention of exposure and evaluate the effectiveness of prevention efforts. The BLRV is based on the 97.5th percentile of the blood lead distribution in U.S. children aged 1-5 years from National Health and Nutrition Examination Survey (NHANES) data. NHANES is a complex, multistage survey designed to provide a nationally representative assessment of health and nutritional status of the noninstitutionalized civilian adult and child populations in the United States (2). The initial BLRV of 5 µg/dL, established in 2012, was based on data from the 2007-2008 and 2009-2010 NHANES cycles. Consistent with recommendations from a former advisory committee, this report updates CDC's BLRV in children to 3.5 µg/dL using NHANES data derived from the 2015-2016 and 2017-2018 cycles and provides helpful information to support adoption by state and local health departments, health care providers (HCPs), clinical laboratories, and others and serves as an opportunity to advance health equity and environmental justice related to preventable lead exposure. CDC recommends that public health and clinical professionals focus screening efforts on populations at high risk based on age of housing and sociodemographic risk factors. Public health and clinical professionals should collaborate to develop screening plans responsive to local conditions using local data. In the absence of such plans, universal BLL testing is recommended. In addition, jurisdictions should follow the Centers for Medicare & Medicaid Services requirement that all Medicaid-enrolled children be tested at ages 12 and 24 months or at age 24-72 months if they have not previously been screened (3).

Shigella sonnei Outbreak Investigation During a Municipal Water Crisis-Genesee and Saginaw Counties, Michigan, 2016.

Objectives. To investigate a shigellosis outbreak in Genesee County, Michigan (including the City of Flint), and Saginaw County, Michigan, in 2016 and address community concerns about the role of the Flint water system.Methods. We met frequently with community members to understand concerns and develop the investigation. We surveyed households affected by the outbreak, analyzed Shigella isolate data, examined the geospatial distribution of cases, and reviewed available water quality data.Results. We surveyed 83 households containing 158 cases; median age was 10 years. Index case-patients from 55 of 83 households (66%) reported contact with a person outside their household who wore diapers or who had diarrhea in the week before becoming ill; results were similar regardless of household drinking water source. Genomic diversity was not consistent with a point source. In Flint, no space-time clustering was identified, and average free chlorine residual values remained above recommended levels throughout the outbreak period.Conclusions. The outbreak was most likely caused by person-to-person contact and not by the Flint water system. Consistent community engagement was essential to the design and implementation of the investigation.

Vitamin E Acetate in Bronchoalveolar-Lavage Fluid Associated with EVALI.

BACKGROUND: The causative agents for the current national outbreak of electronic-cigarette, or vaping, product use-associated lung injury (EVALI) have not been established. Detection of toxicants in bronchoalveolar-lavage (BAL) fluid from patients with EVALI can provide direct information on exposure within the lung. METHODS: BAL fluids were collected from 51 patients with EVALI in 16 states and from 99 healthy participants who were part of an ongoing study of smoking involving nonsmokers, exclusive users of e-cigarettes or vaping products, and exclusive cigarette smokers that was initiated in 2015. Using the BAL fluid, we performed isotope dilution mass spectrometry to measure several priority toxicants: vitamin E acetate, plant oils, medium-chain triglyceride oil, coconut oil, petroleum distillates, and diluent terpenes. RESULTS: State and local health departments assigned EVALI case status as confirmed for 25 patients and as probable for 26 patients. Vitamin E acetate was identified in BAL fluid obtained from 48 of 51 case patients (94%) in 16 states but not in such fluid obtained from the healthy comparator group. No other priority toxicants were found in BAL fluid from the case patients or the comparator group, except for coconut oil and limonene, which were found in 1 patient each. Among the case patients for whom laboratory or epidemiologic data were available, 47 of 50 (94%) had detectable tetrahydrocannabinol (THC) or its metabolites in BAL fluid or had reported vaping THC products in the 90 days before the onset of illness. Nicotine or its metabolites were detected in 30 of 47 of the case patients (64%). CONCLUSIONS: Vitamin E acetate was associated with EVALI in a convenience sample of 51 patients in 16 states across the United States. (Funded by the National Cancer Institute and others.).

Evaluation of Bronchoalveolar Lavage Fluid from Patients in an Outbreak of E-cigarette, or Vaping, Product Use-Associated Lung Injury - 10 States, August-October 2019.

CDC, the Food and Drug Administration (FDA), state and local health departments, and multiple public health and clinical partners are investigating a national outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI). Based on data collected as of October 15, 2019, 86% of 867 EVALI patients reported using tetrahydrocannabinol (THC)-containing products in the 3 months preceding symptom onset (1). Analyses of THC-containing product samples by FDA and state public health laboratories have identified potentially harmful constituents in these products, such as vitamin E acetate, medium chain triglyceride oil (MCT oil), and other lipids (2,3) (personal communication, D.T. Heitkemper, FDA Forensic Chemistry Center, November 2019). Vitamin E acetate, in particular, might be used as an additive in the production of e-cigarette, or vaping, products; it also can be used as a thickening agent in THC products (4). Inhalation of vitamin E acetate might impair lung function (5-7).

Blood and Hair Aluminum Levels, Vaccine History, and Early Infant Development: A Cross-Sectional Study.

OBJECTIVE: To evaluate relationships between whole blood (B-Al) and hair aluminum (H-Al) levels in healthy infants and their immunization history and development. METHODS: We conducted a cross-sectional study of 9- to 13-month-old children recruited from an urban primary care center, excluding those with a history of renal disease or receipt of either aluminum-containing pharmaceuticals or parenteral nutrition. Aluminum levels were measured using inductively coupled plasma-mass spectrometry. Correlation with Bayley Scales of Infant and Toddler Development, Third Edition (BSID) and vaccine-related aluminum load was assessed via linear regression models. RESULTS: The median age of 85 participants was 287 days. B-Al (median, 15.4 ng/mL; range, 0.9-952 ng/mL) and H-Al (median 42,542 ng/g; range, 2758-211,690 ng/g) were weakly correlated (Spearman ρ = 0.26; P = .03). There was no significant correlation between B-Al or H-Al and estimated aluminum load from vaccines. B-Al was not correlated with BSID composite or subscale scores. Although H-Al was not correlated with BSID scores in models including all data (n = 85), it was inversely correlated with motor composite (P < .02; Wald = 5.88) and the gross motor subscale (P = .04; Wald = 4.38) in models that excluded an extreme outlying H-Al value. CONCLUSIONS: Infant B-Al and H-Al varied considerably but did not correlate with their immunization history. Likewise, there was no correlation between B-Al and infant development or between H-Al and language or cognitive development. An inverse correlation between H-Al and BSID motor scores deserves further investigation.

Toxicants in folk remedies: implications of elevated blood lead in an American-born infant due to imported diaper powder.

Though most childhood lead exposure in the USA results from ingestion of lead-based paint dust, non-paint sources are increasingly implicated. We present interdisciplinary findings from and policy implications of a case of elevated blood lead (13-18 mcg/dL, reference level <5 mcg/dL) in a 9-month-old infant, linked to a non-commercial Malaysian folk diaper powder. Analyses showed the powder contains 62 % lead by weight (primarily lead oxide) and elevated antimony [1000 parts per million (ppm)], arsenic (55 ppm), bismuth (110 ppm), and thallium (31 ppm). These metals are highly bioaccessible in simulated gastric fluids, but only slightly bioaccessible in simulated lung fluids and simulated urine, suggesting that the primary lead exposure routes were ingestion via hand-mouth transmission and ingestion of inhaled dusts cleared from the respiratory tract. Four weeks after discontinuing use of the powder, the infant's venous blood lead level was 8 mcg/dL. Unregulated, imported folk remedies can be a source of toxicant exposure. Additional research on import policy, product regulation, public health surveillance, and culturally sensitive risk communication is needed to develop efficacious risk reduction strategies in the USA. The more widespread use of contaminated folk remedies in the countries from which they originate is a substantial concern.

Update: Interim Guidance for Health Care Providers Caring for Women of Reproductive Age with Possible Zika Virus Exposure--United States, 2016.

CDC has updated its interim guidance for U.S. health care providers caring for women of reproductive age with possible Zika virus exposure to include recommendations on counseling women and men with possible Zika virus exposure who are interested in conceiving. This guidance is based on limited available data on persistence of Zika virus RNA in blood and semen. Women who have Zika virus disease should wait at least 8 weeks after symptom onset to attempt conception, and men with Zika virus disease should wait at least 6 months after symptom onset to attempt conception. Women and men with possible exposure to Zika virus but without clinical illness consistent with Zika virus disease should wait at least 8 weeks after exposure to attempt conception. Possible exposure to Zika virus is defined as travel to or residence in an area of active Zika virus transmission ( http://www.cdc.gov/zika/geo/active-countries.html), or sex (vaginal intercourse, anal intercourse, or fellatio) without a condom with a man who traveled to or resided in an area of active transmission. Women and men who reside in areas of active Zika virus transmission should talk with their health care provider about attempting conception. This guidance also provides updated recommendations on testing of pregnant women with possible Zika virus exposure. These recommendations will be updated when additional data become available.

Zika Virus Disease: A CDC Update for Pediatric Health Care Providers.

Zika virus is a mosquito-borne flavivirus discovered in Africa in 1947. Most persons with Zika virus infection are asymptomatic; symptoms when present are generally mild and include fever, maculopapular rash, arthralgia, and conjunctivitis. Since early 2015, Zika virus has spread rapidly through the Americas, with local transmission identified in 31 countries and territories as of February 29, 2016, including several US territories. All age groups are susceptible to Zika virus infection, including children. Maternal-fetal transmission of Zika virus has been documented; evidence suggests that congenital Zika virus infection is associated with microcephaly and other adverse pregnancy and infant outcomes. Perinatal transmission has been reported in 2 cases; 1 was asymptomatic, and the other had thrombocytopenia and a rash. Based on limited information, Zika virus infection in children is mild, similar to that in adults. The long-term sequelae of congenital, perinatal, and pediatric Zika virus infection are largely unknown. No vaccine to prevent Zika virus infection is available, and treatment is supportive. The primary means of preventing Zika virus infection is prevention of mosquito bites in areas with local Zika virus transmission. Given the possibility of limited local transmission of Zika virus in the continental United States and frequent travel from affected countries to the United States, US pediatric health care providers need to be familiar with Zika virus infection. This article reviews the Zika virus, its epidemiologic characteristics, clinical presentation, laboratory testing, treatment, and prevention to assist providers in the evaluation and management of children with possible Zika virus infection.

Update: Interim Guidelines for Health Care Providers Caring for Infants and Children with Possible Zika Virus Infection--United States, February 2016.

CDC has updated its interim guidelines for U.S. health care providers caring for infants born to mothers who traveled to or resided in areas with Zika virus transmission during pregnancy and expanded guidelines to include infants and children with possible acute Zika virus disease. This update contains a new recommendation for routine care for infants born to mothers who traveled to or resided in areas with Zika virus transmission during pregnancy but did not receive Zika virus testing, when the infant has a normal head circumference, normal prenatal and postnatal ultrasounds (if performed), and normal physical examination. Acute Zika virus disease should be suspected in an infant or child aged <18 years who 1) traveled to or resided in an affected area within the past 2 weeks and 2) has ≥2 of the following manifestations: fever, rash, conjunctivitis, or arthralgia. Because maternal-infant transmission of Zika virus during delivery is possible, acute Zika virus disease should also be suspected in an infant during the first 2 weeks of life 1) whose mother traveled to or resided in an affected area within 2 weeks of delivery and 2) who has ≥2 of the following manifestations: fever, rash, conjunctivitis, or arthralgia. Evidence suggests that Zika virus illness in children is usually mild. As an arboviral disease, Zika virus disease is nationally notifiable. Health care providers should report suspected cases of Zika virus disease to their local, state, or territorial health departments to arrange testing and so that action can be taken to reduce the risk for local Zika virus transmission. As new information becomes available, these guidelines will be updated: http://www.cdc.gov/zika/.

Clinical Inquiries Received by CDC Regarding Suspected Ebola Virus Disease in Children--United States, July 9, 2014-January 4, 2015.

The 2014­2015 Ebola virus disease (Ebola) epidemic is the largest in history and represents the first time Ebola has been diagnosed in the United States. On July 9, 2014, CDC activated its Emergency Operations Center and established an Ebola clinical consultation service to assist U.S. state and local public health officials and health care providers with the evaluation of suspected cases. CDC reviewed all 89 inquiries received by the consultation service during July 9, 2014­ January 4, 2015, about children (persons aged ≤18 years). Most (56 [63%]) children had no identifiable epidemiologic risk factors for Ebola; among the 33 (37%) who did have an epidemiologic risk factor, in every case this was travel from an Ebola-affected country. Thirty-two of these children met criteria for a person under investigation (PUI) because of clinical signs or symptoms. Fifteen PUIs had blood samples tested for Ebola virus RNA by reverse transcription­polymerase chain reaction; all tested negative. Febrile children who have recently traveled from an Ebola-affected country can be expected to have other common diagnoses, such as malaria and influenza, and in the absence of epidemiologic risk factors for Ebola, the likelihood of Ebola is extremely low. Delaying evaluation and treatment for these other more common illnesses might lead to poorer clinical outcomes. Additionally, many health care providers expressed concerns about whether and how parents should be allowed in the isolation room. While maintaining an appropriate level of vigilance for Ebola, public health officials and health care providers should ensure that pediatric PUIs receive timely triage, diagnosis, and treatment of other more common illnesses, and care reflecting best practices in supporting children's psychosocial needs.

Active Tracing and Monitoring of Contacts Associated With the First Cluster of Ebola in the United States.

BACKGROUND: Following hospitalization of the first patient with Ebola virus disease diagnosed in the United States on 28 September 2014, contact tracing methods for Ebola were implemented. OBJECTIVE: To identify, risk-stratify, and monitor contacts of patients with Ebola. DESIGN: Descriptive investigation. SETTING: Dallas County, Texas, September to November 2014. PARTICIPANTS: Contacts of symptomatic patients with Ebola. MEASUREMENTS: Contact identification, exposure risk classification, symptom development, and Ebola. RESULTS: The investigation identified 179 contacts, 139 of whom were contacts of the index patient. Of 112 health care personnel (HCP) contacts of the index case, 22 (20%) had known unprotected exposures and 37 (30%) did not have known unprotected exposures but interacted with a patient or contaminated environment on multiple days. Transmission was confirmed in 2 HCP who had substantial interaction with the patient while wearing personal protective equipment. These HCP had 40 additional contacts. Of 20 community contacts of the index patient or the 2 HCP, 4 had high-risk exposures. Movement restrictions were extended to all 179 contacts; 7 contacts were quarantined. Seven percent (14 of 179) of contacts (1 community contact and 13 health care contacts) were evaluated for Ebola during the monitoring period. LIMITATION: Data cannot be used to infer whether in-person direct active monitoring is superior to active monitoring alone for early detection of symptomatic contacts. CONCLUSION: Contact tracing and monitoring approaches for Ebola were adapted to account for the evolving understanding of risks for unrecognized HCP transmission. HCP contacts in the United States without known unprotected exposures should be considered as having a low (but not zero) risk for Ebola and should be actively monitored for symptoms. Core challenges of contact tracing for high-consequence communicable diseases included rapid comprehensive contact identification, large-scale direct active monitoring of contacts, large-scale application of movement restrictions, and necessity of humanitarian support services to meet nonclinical needs of contacts. PRIMARY FUNDING SOURCE: None.

Addressing needs of contacts of Ebola patients during an investigation of an Ebola cluster in the United States - Dallas, Texas, 2014.

The first imported case of Ebola virus disease (Ebola) diagnosed in the United States was confirmed on September 30, 2014; two health care workers who cared for this patient subsequently developed Ebola. Since then, local, state, and federal health officials have continued to prepare for future imported cases, including developing strategies to identify and monitor persons who have had contact with an Ebola patient. This report describes some of the needs of persons who were contacts of Ebola patients in Texas. It is based on requests received from contacts in the course of daily contact tracing interactions and on how those needs were met through community partnerships. Meeting the needs of contacts of the Ebola patients was essential to successful contact tracing, which is critical to interrupting transmission. Although a formal needs assessment of contacts was not conducted, this report provides important information for preparing for an importation of Ebola. Anticipating the nonclinical needs of persons under public health surveillance includes addressing potential concerns about housing, transportation, education, employment, food, and other household needs. Ensuring necessary supports are in place for persons who are asked to refrain from entering public venues can impact their willingness to comply with voluntary and mandated quarantine orders. Engagement with a wide range of community partners, including businesses, schools, charitable foundations, community and faith-based organizations, and mental health resources would enhance public health emergency preparedness for Ebola by readying resources to meet these potential needs.

Clinical inquiries regarding Ebola virus disease received by CDC--United States, July 9-November 15, 2014.

Since early 2014, there have been more than 6,000 reported deaths from Ebola virus disease (Ebola), mostly in Guinea, Liberia, and Sierra Leone. On July 9, 2014, CDC activated its Emergency Operations Center for the Ebola outbreak response and formalized the consultation service it had been providing to assist state and local public health officials and health care providers evaluate persons in the United States thought to be at risk for Ebola. During July 9-November 15, CDC responded to clinical inquiries from public health officials and health care providers from 49 states and the District of Columbia regarding 650 persons thought to be at risk. Among these, 118 (18%) had initial signs or symptoms consistent with Ebola and epidemiologic risk factors placing them at risk for infection, thereby meeting the definition of persons under investigation (PUIs). Testing was not always performed for PUIs because alternative diagnoses were made or symptoms resolved. In total, 61 (9%) persons were tested for Ebola virus, and four, all of whom met PUI criteria, had laboratory-confirmed Ebola. Overall, 490 (75%) inquiries concerned persons who had neither traveled to an Ebola-affected country nor had contact with an Ebola patient. Appropriate medical evaluation and treatment for other conditions were noted in some instances to have been delayed while a person was undergoing evaluation for Ebola. Evaluating and managing persons who might have Ebola is one component of the overall approach to domestic surveillance, the goal of which is to rapidly identify and isolate Ebola patients so that they receive appropriate medical care and secondary transmission is prevented. Health care providers should remain vigilant and consult their local and state health departments and CDC when assessing ill travelers from Ebola-affected countries. Most of these persons do not have Ebola; prompt diagnostic assessments, laboratory testing, and provision of appropriate care for other conditions are essential for appropriate patient care and reflect hospital preparedness.

Response to importation of a case of Ebola virus disease--Ohio, October 2014.

On September 30, 2014, the Texas Department of State Health Services reported a case of Ebola virus disease (Ebola) diagnosed in Dallas, Texas, and confirmed by CDC, the first case of Ebola diagnosed in the United States. The patient (patient 1) had traveled from Liberia, a country which, along with Sierra Leone and Guinea, is currently experiencing the largest recorded Ebola outbreak. A nurse (patient 2) who provided hospital bedside care to patient 1 in Texas visited an emergency department (ED) with fever and was diagnosed with laboratory-confirmed Ebola on October 11, and a second nurse (patient 3) who also provided hospital bedside care visited an ED with fever and rash on October 14 and was diagnosed with laboratory-confirmed Ebola on October 15. Patient 3 visited Ohio during October 10-13, traveling by commercial airline between Dallas, Texas, and Cleveland, Ohio. Based on the medical history and clinical and laboratory findings on October 14, the date of illness onset was uncertain; therefore, CDC, in collaboration with state and local partners, included the period October 10-13 as being part of the potentially infectious period, out of an abundance of caution to ensure all potential contacts were monitored. On October 15, the Ohio Department of Health requested CDC assistance to identify and monitor contacts of patient 3, assess the risk for disease transmission, provide infection control recommendations, and assess and guide regional health care system preparedness. The description of this contact investigation and hospital assessment is provided to help other states in planning for similar events.

Maternal iron metabolism gene variants modify umbilical cord blood lead levels by gene-environment interaction: a birth cohort study.

BACKGROUND: Given the relationship between iron metabolism and lead toxicokinetics, we hypothesized that polymorphisms in iron metabolism genes might modify maternal-fetal lead transfer. The objective of this study was to determine whether maternal and/or infant transferrin (TF) and hemochromatosis (HFE) gene missense variants modify the association between maternal blood lead (MBL) and umbilical cord blood lead (UCBL). METHODS: We studied 476 mother-infant pairs whose archived blood specimens were genotyped for TF P570S, HFE H63D and HFE C282Y. MBL and UCBL were collected within 12 hours of delivery. Linear regression models were used to examine the association between log-transformed MBL and UCBL, examine for confounding and collinearity, and explore gene-environment interactions. RESULTS: The geometric mean MBL was 0.61 µg/dL (range 0.03, 3.2) and UCBL 0.42 (<0.02, 3.9). Gene variants were common with carrier frequencies ranging from 12-31%; all were in Hardy-Weinberg equilibrium. In an adjusted linear regression model, log MBL was associated with log UCBL (ß = 0.92, 95% CI: 0.82, 1.03; p < 0.01) such that a 1% increase in MBL was associated with a 0.92% increase in UCBL among infants born to wild-type mothers. In infants born to C282Y variants, however, a 1% increase in MBL is predicted to increase UCBL 0.65% (ß(Main Effect) = -0.002, 95% CI: -0.09, -0.09; p = 0.97; ß(Interaction) = -0.27, 95% CI: -0.52, -0.01; p = 0.04), representing a 35% lower placental lead transfer among women with MBL 5 µg/dL. CONCLUSIONS: Maternal HFE C282Y gene variant status is associated with greater reductions in placental transfer of lead as MBL increases. The inclusion of gene-environment interaction in risk assessment models may improve efforts to safeguard vulnerable populations.