Common Exposure Research Articles

Principles for Guiding the Selection of Early Childhood Neurodevelopmental Risk and Resilience Measures: HEALthy Brain and Child Development Study as an Exemplar.

The vast individual differences in the developmental origins of risk and resilience pathways combined with sophisticated capabilities of big data science increasingly point to the imperative of large, neurodevelopmental consortia to capture population heterogeneity and key variations in developmental trajectories. At the same time, such large-scale population-based designs involving multiple independent sites also must weigh competing demands. For example, the need for efficient, scalable assessment strategies must be balanced with the need for nuanced, developmentally sensitive phenotyping optimized for linkage to neural mechanisms and specification of common and distinct exposure pathways. Standardized epidemiologic batteries designed for this purpose such as PhenX (consensus measures for Phenotypes and eXposures) and the National Institutes of Health (NIH) Toolbox provide excellent “off the shelf” assessment tools that are well-validated and enable cross-study comparability. However, these standardized toolkits can also constrain ability to leverage advances in neurodevelopmental measurement over time, at times disproportionately advantaging established measures. In addition, individual consortia often expend exhaustive effort “reinventing the wheel,” which is inefficient and fails to fully maximize potential synergies with other like initiatives. To address these issues, this paper lays forth an early childhood neurodevelopmental assessment strategy, guided by a set of principles synthesizing developmental and pragmatic considerations generated by the Neurodevelopmental Workgroup of the HEALthy Brain and Child Development (HBCD) Planning Consortium. These principles emphasize characterization of both risk- and resilience-promoting processes. Specific measurement recommendations to HBCD are provided to illustrate application. However, principles are intended as a guiding framework to transcend any particular initiative as a broad neurodevelopmentally informed, early childhood assessment strategy for large-scale consortia science.

Beverage ethanol exposures among infants reported to United States poison control centers

Background Case studies and small series have demonstrated that beverage ethanol may pose a serious poisoning hazard to infants. Intoxicated infants may not present with the classic signs or symptoms of ethanol poisoning. The objective of this study was to describe the epidemiology of beverage ethanol exposures among infants reported to the United States poison control centers. Methods Data from the National Poison Data System were retrospectively analyzed for infants <12 months of age who were exposed to beverage ethanol from 2009–2018. Results Over the 10-year study period, 1,818 infant exposures to beverage ethanol were reported. Most exposures were single substance (95.2%), and the most common route of exposure was ingestion (n = 1,738). Infants 9–11 months were the most commonly exposed age group subset (45.3%). The annual number and rate of alcoholic beverage exposure increased by 37.5% and 42.9%, respectively, from 2009 to 2018. Of the 563 infants evaluated at a healthcare facility, 38% of exposures were hospitalized. Infants 0–5 months of age had higher odds of being admitted to a non-critical (OR: 2.35, 95% CI: 1.41–3.92) or critical care unit (OR: 2.39; 95% CI: 1.50–3.79) compared to infants 6–11 months of age. Infants 0–5 months of age were more likely to (OR: 4.65; 95% CI: 3.18–6.79) experience a serious outcome compared to infants ages 6–11 months. Five fatalities in infants <6 months old were documented. An in-depth case review identified improper storage and subsequent formula preparation with beverage ethanol as a common exposure mechanism. Conclusions Beverage ethanol exposures among infants are associated with hospitalization, serious clinical effects, and mortality. Infants may present with atypical signs and symptoms of intoxication, requiring a high index of suspicion. Opportunities exist to reduce exposures by addressing improper storage of beverage alcohols.

Prevalence of smoking in the Kuwaiti adult population in 2014: a cross-sectional study.

The study objective was to assess tobacco smoking prevalence in Kuwaiti adults in relation to sociodemographic characteristics. A cross-sectional study survey was conducted in 2014 on 3917 Kuwaiti citizens (18–69 years) following the World Health Organization (WHO) STEPwise Approach to Surveillance (STEPS) methodology. The study assessed prevalence of self-reported ever-smoking or currently smoking tobacco products and exposure to secondhand smoke in relation to demographic and smoking-related characteristics. The prevalence of “ever smoker” in men and women was 49.9% and 4.4%, respectively, whereas the prevalence of “current smoker” was 39.2% and 3.3%, respectively. Sex (adjusted OR [AOR], 19.2 [95% confidence interval (CI) 13.0–28.3], male versus female) was significantly associated with current smoking. Among daily smokers, 87.1% used manufactured cigarettes. The average daily number of manufactured cigarettes for men and women was 21.8 and 13.0, respectively. Mean age at smoking initiation was 17.5 years (95% CI 17.2–17.9). The prevalence of secondhand smoke at home and work was 38.6% and 29.9%, respectively. Half of Kuwaiti men have smoked at some point in their life with most of these being current smokers. Secondhand smoke is a common exposure at home and work, posing serious health risks to the population.

Mumps outbreaks across Canada, 2016 to 2018.

An increase in mumps incidence was observed in late 2016 (365 cases in 2016 compared to 59 cases in 2015). This unusual level of mumps activity prompted the Public Health Network Council and the National Advisory Committee on Immunization to request situation awareness updates from the Centre for Immunization and Respiratory Infectious Diseases (CIRID) at the Public Health Agency of Canada in 2017 and 2018. A mumps outbreak survey was developed and administered by epidemiologists within CIRID and sent electronically to provincial and territorial public health officials in charge of mumps surveillance. The survey collected information on mumps outbreaks pertaining to demographics, risk factors, laboratory data and public health interventions. The first survey collected data on outbreaks occurring between January 1, 2016 and February 28, 2017, while the second survey contained outbreak data from January 1, 2017 to July 31, 2018. Duplicate outbreaks entries were removed. The response rate for the first and second surveys was 61% and 69%, respectively. Twenty-four mumps outbreaks across nine provinces were reported between January 1, 2016 and July 31, 2018, for a cumulative total of 881 mumps cases. Adolescents and adults 15 to 39 years of age accounted for the majority of cases (80.6%). Specifically, adults 20 to 24 years of age represented the largest proportion of cases (24.6%). Community and social gatherings were the most common exposure setting (62.5%). Slightly more than one third of cases were known to have received at least two doses of mumps-containing vaccine (35.6%). Results from the surveys indicate that the increase in mumps activity was widespread throughout Canada, affecting multiple jurisdictions. Young adults accounted for the largest proportion of cases. These surveys provided evidence to support recommendations on the use of additional mumps vaccination in outbreak settings.

Loop Diuretics in Severe Bronchopulmonary Dysplasia: Cumulative Use and Associations with Mortality and Age at Discharge

To measure between-center variation in loop diuretic use in infants developing severe bronchopulmonary dysplasia (BPD) in US children's hospitals, and to compare mortality and age at discharge between infants from low-use centers and infants from high-use centers. We performed a retrospective cohort study of preterm infants at <32weeks of gestational age with severe BPD. The primary outcome was cumulative loop diuretic use, defined as the proportion of days with exposure between admission and discharge. Infant characteristics associated with loop diuretic use at P<.10 were included in multivariable models to adjust for center differences in case mix. Hospitals were ranked from lowest to highest in adjusted use and dichotomized into low-use centers and high-use centers. We then compared mortality and postmenstrual age at discharge between the groups through multivariable analyses. We identified 3252 subjects from 43 centers. Significant variation between centers remained despite adjustment for infant characteristics, with use present in an adjusted mean range of 7.3% to 49.4% of days (P<.0001). Mortality did not differ significantly between the 2 groups (aOR, 0.98; 95% CI, 0.62-1.53; P=.92), nor did postmenstrual age at discharge (marginal mean, 47.3weeks [95% CI, 46.8-47.9weeks] in the low-use group vs 47.4weeks [95% CI, 46.9-47.9weeks] in the high-use group; P=.96). A marked variation in loop diuretic use for infants developing severe BPD exists among US children's hospitals, without an observed difference in mortality or age at discharge. More research is needed to provide evidence-based guidance for this common exposure.

Trampling as a major ecological factor affecting the radial growth and wood anatomy of Scots pine (Pinus sylvestris L.) roots on a hiking trail

The impact of hiking in forested areas is one of the main factors affecting the condition of tree growth along hiking trails. Trampling causes common exposure of roots and quantification of the human impact on root radial growth and wood anatomy requires careful assessment. To accurately identify the radial growth changes in Pinus sylvestris roots, we conducted a stepwise cross-dating using trampled roots from a hiking trail and reference roots. Such approach was previously not applied in a lowland area. In addition, we investigated the factors that influence the root-stem radial growth coherency, including soil properties, root and trail morphology. Changes in radial growth and wood anatomy were examined in three parts of the root system: buried, transition and trampling zone. The radial growth for each root zone was compared with corresponding stem and reference root and stem chronology. In total, we investigated 204 roots and 97 tree stems for the common period 1970–2015. Missing rings were found to be a common phenomenon in all root zones, except in the exposed lateral roots in the trampling zone. The highest number of wedging and missing rings was observed in the trampling and transition zones, respectively. The total number of wedging rings increased with an increasing distance from the stem. The events of root exposure in the trampling zone were highly coupled with the formation of scars (r = 0.51, p < 0.001) and pronounced resin ducts (PRDs) (r = 0.52, p < 0.001). The majority of the wood anatomical changes (i.e., 84% of scars and 85% of PRDs) were identified in the trampling zone. The highest degree of correlation between raw stem chronology and raw root chronology was found for the exposed trampled roots (r = 0.69, p < 0.001). In the trampling zone, the root-stem radial growth coherency was determined primarily by root type (77.3%) and root age (17.4%), whereas in the buried zone, by the soil organic matter content (55.4%) and soil compaction (39.7%). It has been proved that the record of radial growth and wood anatomy changes in Scots pine roots serve as a valuable ecological archive of trampling impact with high temporal resolution.

Outbreak of Haff Disease along the Yangtze River, Anhui Province, China, 2016.

We investigated a large outbreak of Haff disease that occurred along the Yangtze River in Anhui Province, China, in 2016. Of the 672 cases identified during the outbreak, 83.3% (560/672) occurred in Wuhu and Ma’anshan. Patients experienced myalgia (100%) and muscle weakness (54.7%). The mean value of myoglobin was 330 + 121.2 ng/mL and of serum creatine kinase 5,439.2 + 4,765.1 U/L. Eating crayfish was the only common exposure among all cases; 96.8% (240/248) of implicated crayfish were caught on the shores of the Yangtze River or its connected ditches. Mean incubation period was 6.2 + 3.8 hours. This case–control study demonstrated that eating the liver of crayfish and eating a large quantity of crayfish were associated with an increased risk for Haff disease. The seasonal increases in crayfish population along the Yangtze River might explain the seasonal outbreaks of Haff disease.

Assessing the impact of environmental and occupational cancer hazard assessments on policy decision-making: An analysis of US Federal and state regulations

Background: After an occupational or environmental carcinogen is identified as a human hazard, years often pass before policy decisions are enacted that will impact public health. Evaluating the informativeness of hazard assessments on science and regulatory policies is critically important but rarely undertaken. Additionally, no clear approaches exist to measure the influence of cancer hazard conclusions on science-based policy. Using the US Report on Carcinogens (RoC) by the National Toxicology Program, we aim to assess the use of cancer hazard assessments in Federal and state policies, public health impacts, and economic impacts associated with the public health impacts. Methods: We conducted a search of any mention of the RoC in the published regulations on the US Federal Register website, as well as state regulations included in Lexis Advance®. For each regulation, we extracted information on the carcinogen(s) regulated, environmental or occupational media, exposure pathways, tumor site, analyzed public health benefits, and metrics reported in the cost-benefit analysis. Results: Of the identified carcinogens in the RoC from 1994-2019, there were 76 regulations from 8 Federal and 6 state or district agencies that cited the RoC in the notice for regulatory action. The most frequently regulated RoC agents were 1,3-butadiene (N=12), acetaldehyde (N=13), formaldehyde (N=16), and benzene (N=14). The most common exposure sources regulated included air pollutants, manufacturing, and transportation. Of the 51 federal regulations identified, 28 were “economically significant” as defined in Executive Order 12866. The largest overall cancer-related economic benefit was a Federal regulation of occupational exposure to hexavalent chromium, a lung carcinogen. Discussion: Over 25 years, RoC cancer hazard assessments directly informed more than 76 health-based regulatory policies. Expansion of our approach to other cancer and noncancer hazard assessments may ultimately improve our understanding of the effectiveness of scientific conclusions on policymaking.

Exposure patterns among Coast Guard responders to the Deepwater Horizon Oil Spill: a latent class analysis

Disclaimer: The contents, views or opinions expressed in this presentation are those of the author(s) and do not necessarily reflect official policy or position of Uniformed Services University of the Health Sciences, the Department of Defense (DoD), or the United States Coast Guard. Background: The Deepwater Horizon Oil Spill was an environmental crisis for which multiple groups, including the United States Coast Guard (USCG), provided emergency response services. A cohort of 5,665 USCG oil spill responders completed post-deployment surveys on a number of topics, including oil spill-related exposures and experiences. Methods: This secondary data analysis of survey responses used latent class analysis (LCA) methods to determine the most common exposure patterns in this population of responders. Our LCA model was based on six indicator variables assumed to be independent of each other within latent classes. The indicator variables reflected different aspects of the responders’ experiences: exposure to oil, exposure to engine exhaust fumes, hand sanitizer use, sunblock use, mosquito bites, and level of anxiety. To assess the convergent construct validity of these models, we considered the relationship of the latent classes to indicators not used in the latent class models. We also considered the relationship to the types of missions reported by cohort participants. Results: The data were consistent with four exposure profiles, which we interpreted as “low exposure”, “higher environmental hazard exposure and moderate time outdoors, “moderate environmental hazard exposure and more time outdoors”, and “high exposure to both environmental hazards and time outdoors”. The tests for convergent construct validity supported this interpretation of the latent classes. For example, participants in administrative roles were most likely to be in the low-exposure latent class. Conclusions: The exposure pattern variables resulting from this analysis can help inform future studies of the health impacts of exposure mixtures among oil spill responders.

Area under the blood concentration-time curve (AUC) of ethylbenzene concentration in rats: relationship to inhalation and oral administration route-dose

For human risk assessment of toxic chemicals, especially volatile organic compounds (VOCs), the Ministry of the Environment, Government of Japan, has called for the interconversion of inhalation-dose and oral-dose data, two common exposure routes. To address this issue, the present study investigated the time-course changes of ethylbenzene (EB) concentrations in the blood of rats during and after 6-hr inhalation exposure to EB (25, 50, 100, and 200 ppm) and after oral administration of EB by a single oral gavage (25, 50, 100, and 200 mg/kg) of EB. The Area Under the blood concentration-time Curve (AUC) at each blood collection time point (0, 30, 60, 120, 180, 360, 420, 540, and 1440 min, after starting exposure) was determined. The inhalation dose of 25 ppm corresponded closely to the oral administration of 25 mg/kg・bw (r value of 0.859), and the inhalation dose of 200 ppm correlated with the oral administration of 100 mg/kg・bw (r value of 0.948). These results suggest that this comparison using the AUC data at each blood collection time point is valuable for understanding the route- and dose-effects of EB. This study will improve risk assessment of human exposure to EB and other VOCs.

Microbial contamination in the communal-use Lao tobacco waterpipe.

BackgroundThe use of the Asian tobacco waterpipe (TWP) in the Lao People's Democratic Republic represents a potential communal source of infectious disease. This practice of smoking can lead to weakened defences of a smoker's respiratory epithelium, making the smoker vulnerable to respiratory diseases such as coronavirus disease 2019, tuberculosis and others.MethodsThis study evaluated the water quality and hygiene factors among 43 smokers of five villages in rural Luang Namtha Province. Water samples were collected from participant's TWPs and assessed for the presence of Escherichia coli, coliforms and aerobic plate count (APC) bacteria using the 3M Petrifilm.ResultsThe microbial indicator testing results were 95% positive for the APC, 38% positive for coliforms and 17% positive for the E. coli indicator. The concentrations were highest for the APC, with an average of 106 colony forming units (cfu)/ml, followed by coliforms with <100 cfu/ml and lowest for E. coli with <10 cfu/ml. Most TWPs were infrequently cleaned, heavily used and contained a warm, brown-coloured water.ConclusionsThe warm, dark and moist internal water container may facilitate microbial survival and growth. The use of a TWP adds several unstudied modes of transmission to a complex and common biobehavioural and environmental pathogen exposure. Future TWP cessation activities should be tailored to consider risks of infectious disease transmission.

Blood Phosphatidylethanol Concentrations Following Regular Exposure to an Alcohol-Based Mouthwash.

Direct biomarkers of ethanol are used to monitor individuals who are required to abstain from ethanol consumption. In recent years, blood phosphatidylethanol (PEth) has gained acceptance in clinical and forensic contexts as an abstinence marker. Its elimination half-life of several days provides a window of detection of days to weeks. However, there is no research addressing the extent of PEth formation related to extraneous ethanol exposures. To assess the degree of ethanol absorption and subsequent formation of blood PEth related a common extraneous exposure, regular use of an ethanol-containing mouthwash, we recruited 16 participants to gargle with an alcohol-based mouthwash (21.6% ethanol) 4 times daily, for 12 consecutive days. Blood was analyzed for PEth 16:0/18:1 by liquid chromatography-tandem mass spectrometry. Our hypothesis that blood PEth concentrations would not equal or exceed 20 ng/mL was confirmed. Although the data suggest that regular use of mouthwash is unlikely to result in suprathreshold PEth concentrations, this work highlights the importance of considering extraneous ethanol exposures in clinical decision-making and in future research.

Research progress on toxic effects and biomarkers of organophosphate ester flame retardant exposures

Organophosphate ester (OPEs) has been widely used as a substitute of brominated biphenyl ethers and other brominated flame retardant (BFRs), and their health effects and environmental impacts are widely concerned. This article systematically reviews the common types, metabolites, environmental occurrences, exposure pathways, levels, toxic effects and biomarkers of OPEs, in order to explore the relationships between OPEs exposures and biomarkers, to reveal the potential mechanisms of health effects, and to provide references and scientific basis for the health effects of OPEs exposure in China.

Meta-analysis of anti-Saccharomyces cerevisiae antibodies as diagnostic markers of Behçet’s disease with gastrointestinal involvement

ObjectiveDue to common exposure to yeast in the alcoholic and baking industry, positive rate of anti-Saccharomyces cerevisiae antibodies (ASCA) is reportedly high in patients with Behçet’s disease (BD) who have...

An Assessment of School Going Population Exposure Pathways to Agropesticide in the Mungo Corridor of Cameroon

Pesticide use in agricultural holdings closer to dwellings exposes the population to its noxious effects. This study is set on the premise that although pesticide seems a panacea for crop protection, it has continued to wreak havoc on farmers’ health and especially school going population who are exposed to pesticide use in nearby agroindustrial plantations in the Mungo Corridor. The study objectives are to identify students who use pesticides and why they use these toxic chemicals. In this same vein, it probes into identifying some common pesticides exposure pathways among students and the resultant effects of these toxic chemicals on them. The study employed both primary and secondary data, and key informant interviews with resource persons. Data was collected through a survey of 510 students across 10 schools in two subdivisions. Data analysis was run on Microsoft Excel 2016 and SPSS 16.0, employing descriptive (percentage indices, charts, mean, median) and inferential (Kruskal-Wallis (H-Test), Mann Whitney (U-Test), and ChiSquare test) statistics. Findings revealed that school going population is potentially exposed to pesticides via different exposure pathways, justified by the proximity of schools to agroindustrial banana plantations where pesticides are sprayed using helicopters. Also, majority of students (85%) use pesticides for various reasons with little or no knowledge on the methods of use which further broadens their exposure. A weighted analysis of data revealed that there was a significant difference between students’ education level and some hypothesized explanatory variables (p&lt;0.05), implying that lack of information by students on how to avoid contacts with pesticides further exposes them. However, the paper concludes that receiving training in the safe use of pesticides by students and providing wind barriers in agroindustrial banana plantations to prevent spray drifts from entering into school yards and residence are key solutions to this danger.

Geographic Links and Predictable Returns

Using detailed information on establishments owned by U.S. public firms, we construct a novel measure of geographic linkage between firms. We show that the returns of geography-linked firms have strong predictive power for focal firm returns and fundamentals. A long-short strategy based on this effect yields monthly value-weighted alpha of approximately 60 basis points. This effect is distinct from other cross-firm return predictability and is not easily attributable to risk-based explanations. It is more pronounced for focal firms that receive lower investor attention, are more costly to arbitrage, and during high sentiment periods. Sell-side analysts similarly underreact, as their forecast revisions of geography-linked firms predict their future revisions of focal firms. Further tests suggest that the lead-lag relation we document results from innovation spillover among geographic peers in addition to their common exposure to the local economy.

Normative formaldehyde-hemoglobin adduct levels among the US Population: Analysis of the 2013–2016 National Health and Nutrition Examination Survey

IntroductionFormaldehyde (FA) is currently classified as a known carcinogen. In addition to being a ubiquitous compound with many common exogenous exposure sources, it is also part of multiple metabolic pathways and present in every living cell. The objectives of this study were to determine normative levels of FA as measured by FA-Hemoglobin (Hb) adducts in the United States (US) and to determine if FA-Hb levels differ based on a variety of demographic factors. MethodsData collected between 2013 and 2016 by the National Health and Nutrition Examination Survey were assessed from 4521 participants representing approximately 244 million individuals living in the US. General linear models were used to examine associations between FA-Hb adducts and sample characteristics. FA-Hb levels were summarized using geometric mean concentrations (GMC) and associated 95% confidence intervals (CI). ResultsThe overall GMC was 131.10 nmol/g Hb (95% CI 129.39–132.83). Analyses revealed no evidence to support associations between FA-Hb levels and age, gender, income, or nicotine use. Among adults, non-Hispanic Black race was associated with lower FA-Hb levels compared to all other race/ethnicity groups, P < 0.01. ConclusionThe study provides the first normative values for FA in adults and children. These data could be a tool to assess the body’s response to acute and chronic exposure.

Dietary patterns, foods and nutrients: a descriptive analysis of the systematic reviews conducted to inform the Australian Dietary Guidelines.

Dietary guidelines should be underpinned by the best available evidence on relationships between diet and health, including evidence from nutrient-based, food-based and dietary patterns research. The primary aim of the present study was to analyse the systematic reviews conducted to inform the 2013 Australian Dietary Guidelines according to dietary exposure. The secondary aim was to analyse the reviews by health outcome, and design of included studies. To identify the systematic reviews, the dietary guidelines report was used as a starting point and relevant references were retrieved. The evidence report contained the data used in this analysis. Descriptive statistics were used to analyse reviews according to exposure, outcome, and design of included studies. A total of 143 systematic reviews were included in this analysis. Foods were the most common exposure (86·7 % of reviews), followed by nutrients (10·5 %) and dietary patterns (2·8 %). Chronic disease morbidity and/or mortality was the most common outcome (80·4 %), followed by chronic disease risk factors (19·6 %). Most reviews included evidence from cohort or nested case-control studies (92·3 %), many included evidence from case-control studies (61·5 %) and some included evidence from randomised controlled trials (28·7 %). These results reflect the research questions that were asked, the systematic review methods that were used, and the evidence that was available. In developing future iterations of the Australian Dietary Guidelines, there is an opportunity to review the latest evidence from dietary patterns research.

Epidemiological analysis on a family cluster of COVID-19

Objective: To understand the possible transmission route of a family cluster of COVID-19 in Zhengzhou and the potential infectivity of COVID-19 in incubation period, and provide scientific evidence for the timely control of infectious source and curb the spread of the epidemic. Methods: Epidemiological investigation was conducted for a family cluster of COVID-19 (8 cases) with descriptive epidemiological method, and respiratory tract samples of the cases were collected for the nucleic acid detection of virus by RT-PCR. Results: Two primary cases, which occurred on 31 January and 1 February, 2020, respectively, had a common exposure history in Wuhan. The other six family members had onsets on 30 January, 31 January, 1 February (three cases) and 3 February, 2020. Conclusions: In this family cluster of COVID-19, six family members were infected through common family exposure to the 2 primary cases. Five secondary cases had onsets earlier than or on the same day as the primary cases, indicating that COVID-19 is contagious in incubation period, and the home isolation in the early phase of the epidemic might lead to the risk of family cluster of COVID-19.

COVID-19 outbreak in Jordan: Epidemiological features, clinical characteristics, and laboratory findings

BackgroundIn March 2020, an outbreak of coronavirus 19 (COVID-19) was detected in the North of Jordan. This retrospective study is the first from Jordan to report the epidemiologic, clinical, laboratory, and radiologic characteristics of COVID-19 infected patients. MethodsAll patients with laboratory-confirmed COVID-19 infection by RT-PCR in the North of Jordan admitted between March 15 and April 2, 2020 were included. The clinical features, radiological, and laboratory findings were reviewed. ResultsOf 81 patients affected, 79 (97.5%) shared a common exposure to four recent travelers from endemic areas. The mean age was 40 years. Although about half (44 [54.3%]) were females, symptomatic patients were mostly females (75%). The most common presenting symptoms were nasal congestion, sore throat and dry cough. Less than one-third (31%) had chronic diseases. Although 84% of patients reported receiving Bacille Calmette-Guérin (BCG) vaccination, more asymptomatic patients had BCG than symptomatic (p = 0.017). Almost all patients (97.5%) had an elevated D-dimer level. Erythrocyte sedimentation rate (ESR) and c-reactive protein were elevated in 50% and 42.7% of patients, respectively. High ESR found to be the predictor of abnormal chest radiograph observed in 13 (16%) patients with OR of 14.26 (95% CI 1.37–147.97, p = 0.026). ConclusionsAn outbreak of COVID-19 infection in northern Jordan affected more females and relatively young individuals and caused mainly mild illnesses. The strict outbreak response measures applied at early stages probably contributed to the lenient nature of this outbreak, but the contribution of other factors to such variability in COVID-19 presentation is yet to be explained.