Incidents of potential public health significance identified using national surveillance of US poison center data (2008-2012).

BACKGROUND: The Centers for Disease Control and Prevention (CDC) and the American Association of Poison Control Centers conduct national surveillance on data collected by US poison centers to identify incidents of potential public health significance (IPHS). The overarching goals of this collaboration are to improve CDC's national surveillance capacity for public health threats, identify early markers of public health incidents and enhance situational awareness. The National Poison Data System (NPDS) is used as a surveillance system to automatically identify data anomalies. PURPOSE: To characterize data anomalies and IPHS captured by national surveillance of poison center data over 5 years. METHODS: Data anomalies are identified through three surveillance methodologies: call-volume, clinical effect, and case-based. Anomalies are reviewed by a team of epidemiologists and clinical toxicologists to determine IPHS using standardized criteria. The authors reviewed IPHS identified by these surveillance activities from 2008 through 2012. RESULTS: Call-volume surveillance identified 384 IPHS; most were related to gas and fume exposures (n = 229; 59.6%) with the most commonly implicated substance being carbon monoxide (CO) (n = 92; 22.8%). Clinical-effect surveillance identified 138 IPHS; the majority were related to gas and fume exposures (n = 58; 42.0%) and gastrointestinal complaints (n = 84; 16.2%), and the most commonly implicated substance was CO (n = 20; 14.4%). Among the 11 case-based surveillance definitions, the botulism case definition yielded the highest percentage of identified agent-specific illness. CONCLUSIONS: A small proportion of data anomalies were designated as IPHS. Of these, CO releases were the most frequently reported IPHS and gastrointestinal syndromes were the most commonly reported illness manifestations. poison center data surveillance may be used as an approach to identify exposures, illnesses, and incidents of importance at the national and state level.

Characterizing concentrations of diethylene glycol and suspected metabolites in human serum, urine, and cerebrospinal fluid samples from the Panama DEG mass poisoning.

CONTEXT: Diethylene glycol (DEG) mass poisoning is a persistent public health problem. Unfortunately, there are no human biological data on DEG and its suspected metabolites in poisoning. If present and associated with poisoning, the evidence for use of traditional therapies such as fomepizole and/or hemodialysis would be much stronger. OBJECTIVE: To characterize DEG and its metabolites in stored serum, urine, and cerebrospinal fluid (CSF) specimens obtained from human DEG poisoning victims enrolled in a 2006 case-control study. METHODS: In the 2006 study, biological samples from persons enrolled in a case-control study (42 cases with new-onset, unexplained AKI and 140 age-, sex-, and admission date-matched controls without AKI) were collected and shipped to the Centers for Disease Control and Prevention (CDC) in Atlanta for various analyses and were then frozen in storage. For this study, when sufficient volume of the original specimen remained, the following analytes were quantitatively measured in serum, urine, and CSF: DEG, 2-hydroxyethoxyacetic acid (HEAA), diglycolic acid, ethylene glycol, glycolic acid, and oxalic acid. Analytes were measured using low resolution GC/MS, descriptive statistics calculated and case results compared with controls when appropriate. Specimens were de-identified so previously collected demographic, exposure, and health data were not available. The Wilcoxon Rank Sum test (with exact p-values) and bivariable exact logistic regression were used in SAS v9.2 for data analysis. RESULTS: The following samples were analyzed: serum, 20 case, and 20 controls; urine, 11 case and 22 controls; and CSF, 11 samples from 10 cases and no controls. Diglycolic acid was detected in all case serum samples (median, 40.7 mcg/mL; range, 22.6-75.2) and no controls, and in all case urine samples (median, 28.7 mcg/mL; range, 14-118.4) and only five (23%) controls (median, < Lower Limit of Quantitation (LLQ); range, < LLQ-43.3 mcg/mL). Significant differences and associations were identified between case status and the following: 1) serum oxalic acid and serum HEAA (both OR = 14.6; 95% C I = 2.8-100.9); 2) serum diglycolic acid and urine diglycolic acid (both OR > 999; exact p < 0.0001); and 3) urinary glycolic acid (OR = 0.057; 95% C I = 0.001-0.55). Two CSF sample results were excluded and two from the same case were averaged, yielding eight samples from eight cases. Diglycolic acid was detected in seven (88%) of case CSF samples (median, 2.03 mcg/mL; range, < LLQ, 7.47). DISCUSSION: Significantly elevated HEAA (serum) and diglycolic acid (serum and urine) concentrations were identified among cases, which is consistent with animal data. Low urinary glycolic acid concentrations in cases may have been due to concurrent AKI. Although serum glycolic concentrations among cases may have initially increased, further metabolism to oxalic acid may have occurred thereby explaining the similar glycolic acid concentrations in cases and controls. The increased serum oxalic acid concentration results in cases versus controls are consistent with this hypothesis. CONCLUSION: Diglycolic acid is associated with human DEG poisoning and may be a biomarker for poisoning. These findings add to animal data suggesting a possible role for traditional antidotal therapies. The detection of HEAA and diglycolic acid in the CSF of cases suggests a possible association with signs and symptoms of DEG-associated neurotoxicity. Further work characterizing the pathophysiology of DEG-associated neurotoxicity and the role of traditional toxic alcohol therapies such as fomepizole and hemodialysis is needed.

Characterizing risk factors for pediatric lamp oil product exposures.

UNLABELLED: Poisonings from lamp oil ingestion continue to occur worldwide among the pediatric population despite preventive measures such as restricted sale of colored and scented lamp oils. This suggests that optimal prevention practices for unintentional pediatric exposures to lamp oil have yet to be identified and/or properly implemented. OBJECTIVE: To characterize demographic, health data, and potential risk factors associated with reported exposures to lamp oil by callers to poison centers (PCs) in the US and discuss their public health implications. STUDY DESIGN: This was a two part study in which the first part included characterizing all exposures to a lamp oil product reported to the National Poison Data System (NPDS) with regard to demographics, exposure, health, and outcome data from 1/1/2000 to 12/31/2010. Regional penetrance was calculated using NPDS data by grouping states into four regions and dividing the number of exposure calls by pediatric population per region (from the 2000 US census). Temporal analyses were performed on NPDS data by comparing number of exposures by season and around the July 4th holiday. Poisson regression was used to model the count of exposures for these analyses. In the second part of this project, in order to identify risk factors we conducted a telephone-based survey to the parents of children from five PCs in five different states. The 10 most recent lamp oil product exposure calls for each poison center were systematically selected for inclusion. Calls in which a parent or guardian witnessed a pediatric lamp oil product ingestion were eligible for inclusion. Data on demographics, exposure information, behavioral traits, and health were collected. A descriptive analysis was performed and Fisher's exact test was used to evaluate associations between variables. All analyses were conducted using SAS v9.3. RESULTS: Among NPDS data, 2 years was the most common patient age reported and states in the Midwestern region had the highest numbers of exposure calls compared to other regions. Exposure calls differed by season (p < 0.0001) and were higher around the July 4th holiday compared to the rest of the days in July (2.09 vs. 1.89 calls/day, p < 0.002). Most exposures occurred inside a house, were managed on-site and also had a "no effect" medical outcome. Of the 50 PC-administered surveys to parents or guardians, 39 (78%) met inclusion criteria for analysis. The majority of ingestions occurred in children that were 2 years of age, that were not alone, involved tiki torch fuel products located on a table or shelf, and occurred inside the home. The amount of lamp oil ingested did not appear to be associated with either the smell (p = 0.19) or the color of the oil (p = 1.00) in this small sample. Approximately half were asymptomatic (n = 18; 46%), and of those that reported symptoms, cough was the most common (n = 20, 95%) complaint. CONCLUSIONS: Lamp oil product exposures are most common among young children (around 2 years of age) while at home, not alone and likely as a result of the product being in a child-accessible location. Increasing parental awareness about potential health risks to children from these products and teaching safe storage and handling practices may help prevent both exposures and associated illness. These activities may be of greater benefit in Midwestern states and during summer months (including the period around the July 4th holiday).

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis: an etiology worth considering in the differential diagnosis of delirium.

BACKGROUND: Medical toxicologists are frequently consulted when young patients present with delirium attributed to suspected poisoning. Medical toxicologists should be aware of non-toxicological mimics of delirium. We describe two patients ultimately diagnosed with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis for which a toxicological consultation was requested to evaluate for neuroleptic malignant syndrome (NMS). CASE 1: A 21 year old male was sent from a psychiatric facility for new, worsening psychotic symptoms. He had autonomic instability, confusion, and hyper-reflexia. He was treated for NMS without improvement, and after an extensive workup was unrevealing, he was discharged home with significant cognitive dysfunction. Stored CSF later tested positive for anti-NMDAR antibodies. CASE 2: A 27 year old female was sent from a psychiatric facility for a seizure and new psychiatric symptoms. She was agitated and had violent, alternating extremity flexion and extension along with autonomic instability. She was treated for NMS, rhabdomyolysis, and rabies before analysis of CSF demonstrated anti-NMDAR antibodies. Treatment included surgical resection of a suspicious ovarian cyst, steroids and IVIG, with moderate improvement. DISCUSSION: Autoimmune syndromes of the central nervous system result from receptor dysfunction after an antibody response to extracellular or intracellular antigens, such as subunits of the NMDA receptor. The NMDA subunits NR2b and NR2a, in addition to the N-terminal region of the glycine binding NR1 subunit, have been implicated. Typical features such as memory loss, movement disorders, and hallucinations reflect the density and distribution of neuronal NDMA receptors. As young people, particularly young women, are predominantly affected, initial symptoms may be attributed to encephalopathy from drug abuse or schizophrenia. Toxicologists may be consulted as many features mimic NMS. Serum and cerebrospinal fluid can be checked for anti-NMDAR antibodies as part of a paraneoplastic or meningioencephalitis panel. Effective treatments have been described and include surgical resection and immunosuppressive medications.