Corrigendum: Factors associated with COVID-19 vaccine confidence among primary care providers in Kazakhstan, March-April 2021.

[This corrects the article DOI: 10.3389/fpubh.2023.1245750.].

Factors associated with COVID-19 vaccine confidence among primary care providers in Kazakhstan, March-April 2021.

Introduction: Vaccination is a critical public health intervention, and vaccine hesitancy is a major threat. Globally, confidence in COVID-19 vaccines has been low, and rates of routine immunizations decreased during the COVID-19 pandemic. Because healthcare providers are a trusted source of information on vaccination in Kazakhstan, it was vital to understand their knowledge, attitudes and practices (KAP) related to both routine and COVID-19 vaccines. Methods: From March to April 2021, we conducted a cross-sectional study among the healthcare providers responsible for vaccination in 54 primary care facilities in three cities in Kazakhstan. All consenting providers anonymously completed structured online questionnaires at their place of work. A provider was classified as having COVID-19 vaccine confidence if they planned to get a COVID-19 vaccine, believed that COVID-19 vaccines are important to protect their community and either believed the vaccine was important to protect themselves or believed that getting a vaccine was safer than getting COVID-19. Statistical analysis included chi-square, Spearman's rank correlation coefficient, and Poisson regression. Results: Of 1,461 providers, 30% had COVID-19 vaccine confidence, 40% did not, and 30% would refuse vaccination. Participants were mostly female (92%) and ≤ 35 years old (57%). Additionally, 65% were nurses, 25% were family physicians, and 10% were pediatricians. Adequate KAP for routine vaccines was low (22, 17, and 32%, respectively). Adequate knowledge was highest among pediatricians (42%) and family physicians (28%) and lowest among nurses (17%). Misconceptions about vaccines were high; 54% believed that influenza vaccines cause flu, and 57% believed that there is a scientifically proven association between vaccination and autism and multiple sclerosis. About half (45%) of the practitioners felt confident answering patient vaccine-related concerns. In adjusted models, COVID-19 vaccine confidence was positively associated with adequate knowledge of vaccines (prevalence ratio: 1.2, 95% confidence interval: 1.0-1.4) and adequate attitudes related to routine vaccines (3.1, 2.7-3.6). Conclusion: Our study uncovers critical areas for interventions to improve KAP related to routine immunizations and COVID-19 vaccine confidence among providers in Kazakhstan. The complex relationship between KAP of routine vaccines and COVID-19 vaccine confidence underscores the importance of addressing vaccine hesitancy more broadly and not focusing solely on COVID-19.

Oral cholera vaccine coverage evaluation survey: Forcibly Displaced Myanmar Nationals and host community in Cox's Bazar, Bangladesh.

Introduction: Cholera remains a significant public health concern in many parts of the world, particularly in areas with poor sanitation and hygiene. Bangladesh and other impoverished nations have been severely affected by cholera outbreaks, especially in areas with a high population density. In order to mitigate the spread of cholera, oral cholera vaccines (OCVs) are recommended as a prophylactic measure. In May 2018, 775,666 of the Forcibly Displaced Myanmar Nationals (FDMN) in the registered and makeshift camps and 103,605 of the residents in the host community received two doses of OCV ShancholTM in Cox's Bazar, Bangladesh, because the conditions in the area favored the transmission of cholera and other waterborne diseases. This study aimed to assess the coverage of OCV among the FDMN and the host community in Cox's Bazar. Methods: In August 2018, we enrolled 4,240 respondents for this study following the "World Health Organization (WHO) Vaccination Coverage Cluster Surveys: Reference Manual (2018)." The coverage survey was conducted with three strata of the population: the host community from the Teknaf Upazila, the registered camp, and the makeshift camp from the Ukhia Upazila. We collected information regarding OCV coverage, demographic characteristics, and knowledge and behaviors of people toward the vaccine. The data were analyzed using descriptive statistics. Results: According to our study, the overall OCV coverage was 85%, with 68% in the host community, 91% in the registered camp, and 98% in the makeshift camp. The lower coverage in the host community was due to residents unaware of the vaccination campaign, the unavailability of vaccines, and unaware where to go for vaccination. Discussion: Our findings demonstrate that the OCV campaign in the FDMN camps was successful, reaching over 90% coverage, while coverage in the host community was much lower. In order to make sure that OCV vaccination efforts are reaching the target population and having the desired impact, our study emphasizes the need to inform the target population of when and where to get vaccinated.

Effectiveness of four vaccines in preventing SARS-CoV-2 infection in Almaty, Kazakhstan in 2021: retrospective population-based cohort study.

Background: In February 2021 Kazakhstan began offering COVID-19 vaccines to adults. Breakthrough SARS-CoV-2 infections raised concerns about real-world vaccine effectiveness. We aimed to evaluate effectiveness of four vaccines against SARS-CoV-2 infection. Methods: We conducted a retrospective cohort analysis among adults in Almaty using aggregated vaccination data and individual-level breakthrough COVID-19 cases (≥14 days from 2nd dose) using national surveillance data. We ran time-adjusted Cox-proportional-hazards model with sensitivity analysis accounting for varying entry into vaccinated cohort to assess vaccine effectiveness for each vaccine (measured as 1-adjusted hazard ratios) using the unvaccinated population as reference (N = 565,390). We separately calculated daily cumulative hazards for COVID-19 breakthrough among vaccinated persons by age and vaccination month. Results: From February 22 to September 1, 2021, in Almaty, 747,558 (57%) adults were fully vaccinated (received 2 doses), and 108,324 COVID-19 cases (11,472 breakthrough) were registered. Vaccine effectiveness against infection was 79% [sensitivity estimates (SE): 74%-82%] for QazVac, 77% (SE: 71%-81%) for Sputnik V, 71% (SE: 69%-72%) for Hayat-Vax, and 70% (SE: 65%-72%) for CoronaVac. Among vaccinated persons, the 90-day follow-up cumulative hazard for breakthrough infection was 2.2%. Cumulative hazard was 2.9% among people aged ≥60 years versus 1.9% among persons aged 18-39 years (p < 0.001), and 1.2% for people vaccinated in February-May versus 3.3% in June-August (p < 0.001). Conclusion: Our analysis demonstrates high effectiveness of COVID-19 vaccines against infection in Almaty similar to other observational studies. Higher cumulative hazard of breakthrough among people ≥60 years of age and during variant surges warrants targeted booster vaccination campaigns.

Knowledge, Attitude and Practice of Commercial Sex Workers Regarding Cervical Cancer and Its Screening, Daulatdia Brothel, Rajbari District, Bangladesh, 2020-2021.

Background: Cervical cancer is the second most common cancer in females in Bangladesh. This is caused by Human Papilloma Virus (HPV). Multiple sex partners, HIV infection, smoking, using birth control pills, and having more than three children are risk factors of cervical cancer. Hence, female sex workers have a high prevalence of infection with high risk HPV genotypes which eventually may causes cervical cancer. Unfortunately, the status of knowledge, attitude and practice among female sex workers regarding cervical cancer is mostly unknown. The aim of the study was to assess the knowledge, attitude and practice of women living in Daulatdia brothel regarding cervical cancer and its screening.  Methods: A cross-sectional knowledge-practice survey was conducted among 400 female sex workers in Daulatdia Brothel, Rajbari District, Bangladesh. The women's total score on knowledge, and practice were categorized as sufficient or insufficient. We calculated frequencies and used binary logistic regression to describe and assess the association between scores and socio-demographic characteristics of respondents. Results: Most sex workers (61%) were between 29 to 35 years, married at 13 to 15 years of age, and divorced (91%). Middle aged sex workers were more likely have a VIA test  than women in the 29 to 35 years group (18%, OR:5.2; CI: 2.0, 13.5). Less than half of the studied women (40%) had sufficient knowledge regarding cervical cancer and 12% knew that infection by HPV is a risk factor. Respondents with primary and secondary education were more likely to have sufficient knowledge than the illiterate (42%, OR: 1.32; CI: 0.82, 2.12). Practices to prevent cervical cancer were very poor. Nearly all women (99%) would recommend other women to have a VIA test. There were only 7% who had a VIA test and 2% were vaccinated against HPV. Unmarried sex workers were more likely to take action to prevent cervical cancer. Sex workers educated up to the primary level were more likely to have a VIA or other tests than the illiterate sex workers (10%, OR: 1.3; CI: 0.6, 3.2). Conclusion: Sex workers in Daulatdia brothel were less knowledgeable about cervical cancer and less likely to have a VIA test and poor practices towards preventing cervical cancer. The sex workers underutilized the VIA test and HPV vaccine.

Late diagnosis of Lassa fever outbreak in endemic areas lead to high mortality, Kenema District, Sierra Leone, February - March 2019.

Introduction: the Kenema District Surveillance team in Sierra Leone received notifications of patients with suspected Lassa fever on February 20th and March 2nd, 2019. On that day, an investigation started to confirm the diagnosis and search for additional cases. Methods: we used the Lassa fever surveillance case definition and collected demographic and exposure information from suspected cases through interviews and clinical records. Blood samples were collected from the cases to confirm the diagnosis. Active case finding was conducted in the community and health facility. Results: on February 10, 2019, an eight-year-old male developed a fever (>39.5°C) and a sore throat. On February 18, 2019, he was admitted to a hospital and treated for malaria and pneumonia. On February 20, 2019, Lassa fever was suspected because the patient was bleeding from orifices and testing. On February 15, a 5-year-old female developed fever and headache and was treated with anti-malarial drugs. On February 26th the high fever re-emerged with severe bleeding from the orifices. She was admitted and treated with antibiotics, confirmed for Lassa fever, and died on March 2, 2019. Conclusion: the two children had Lassa fever, and no additional cases were identified. We sensitized clinicians on suspicion of Lassa fever to improve early detection and treatment.

Strengthening the global one health workforce: Veterinarians in CDC-supported field epidemiology training programs.

Background: Effective prevention, detection, and response to disease threats at the human-animal-environment interface rely on a multisectoral, One Health workforce. Since 2009, the U.S. Centers for Disease Control and Prevention (CDC) has supported Field Epidemiology Training Programs (FETPs) to train veterinarians and veterinary paraprofessionals (VPPs) alongside their human health counterparts in the principles of epidemiology, disease surveillance, and outbreak investigations. We aim to describe and evaluate characteristics of CDC-supported FETPs enrolling veterinarians/VPPs to understand these programs contribution to the strengthening of the global One Health workforce. Methods: We surveyed staff from CDC-supported FETPs that enroll veterinarians and VPPs regarding cohort demographics, graduate retention, and veterinary and One Health relevant curriculum inclusion. Descriptive data was analyzed using R Version 3.5.1. Results: Forty-seven FETPs reported veterinarian/VPP trainees, 68% responded to our questionnaire, and 64% reported veterinary/VPP graduates in 2017. The veterinary/VPP graduates in 2017 made up 12% of cohorts. Programs reported 74% of graduated veterinarians/VPPs retained employment within national ministries of agriculture. Common veterinary and One Health curriculum topics were specimen collection and submission (93%), zoonotic disease (90%) and biosafety practices (83%); least covered included animal/livestock production and health promotion (23%) and transboundary animal diseases (27%). Less than half (41%) of programs reported the curriculum being sufficient for veterinarians/VPPs to perform animal health specific job functions, despite most programs being linked to the ministry of agriculture (75%) and providing veterinary-specific mentorship (63%). Conclusions: Our results indicate that FETPs provide valuable training opportunities for animal health sector professionals, strengthening the epidemiology capacity within the ministries retaining them. While veterinary/VPP trainees could benefit from the inclusion of animal-specific curricula needed to fulfill their job functions, at present, FETPs continue to serve as multisectoral, competency-based, in-service training important in strengthening the global One Health workforce by jointly training the animal and human health sectors.

Large outbreak of Jimsonweed (Datura stramonium) poisoning due to consumption of contaminated humanitarian relief food: Uganda, March-April 2019.

BACKGROUND: Jimsonweed (Datura stramonium) contains toxic alkaloids that cause gastrointestinal and central nervous system symptoms when ingested. This can be lethal at high doses. The plant may grow together with leguminous crops, mixing with them during harvesting. On 13 March 2019, more than 200 case-patients were admitted to multiple health centres for acute gastrointestinal and neurologic symptoms. We investigated to determine the cause and magnitude of the outbreak and recommended evidence-based control and prevention measures. METHODS: We defined a suspected case as sudden onset of confusion, dizziness, convulsions, hallucinations, diarrhoea, or vomiting with no other medically plausible explanations in a resident of Napak or Amudat District from 1 March-30 April 2019. We reviewed medical records and canvassed all villages of the eight affected subcounties to identify cases. In a retrospective cohort study conducted in 17 villages that reported the earliest cases, we interviewed 211 residents about dietary history during 11-15 March. We used modified Poisson regression to assess suspected food exposures. Food samples underwent chemical (heavy metals, chemical contaminants, and toxins), proteomic, DNA, and microbiological testing in one national and three international laboratories. RESULTS: We identified 293 suspected cases; five (1.7%) died. Symptoms included confusion (62%), dizziness (38%), diarrhoea (22%), nausea/vomiting (18%), convulsions (12%), and hallucinations (8%). The outbreak started on 12 March, 2-12 h after Batch X of fortified corn-soy blend (CSB +) was distributed. In the retrospective cohort study, 66% of 134 persons who ate CSB + , compared with 2.2% of 75 who did not developed illness (RRadj = 22, 95% CI = 6.0-81). Samples of Batch X distributed 11-15 March contained 14 tropane alkaloids, including atropine (25-50 ppm) and scopolamine (1-10 ppm). Proteins of Solanaceae seeds and Jimsonweed DNA were identified. No other significant laboratory findings were observed. CONCLUSION: This was the largest documented outbreak caused by food contamination with tropane alkaloids. Implicated food was immediately withdrawn. Routine food safety and quality checks could prevent future outbreaks.

Factors Associated with an Outbreak of COVID-19 in Oilfield Workers, Kazakhstan, 2020.

From March to May 2020, 1306 oilfield workers in Kazakhstan tested positive for SARS-CoV-2. We conducted a case-control study to assess factors associated with SARS-CoV-2 transmission. The cases were PCR-positive for SARS-CoV-2 during June-September 2020. Controls lived at the same camp and were randomly selected from the workers who were PCR-negative for SARS-CoV-2. Data was collected telephonically by interviewing the oil workers. The study had 296 cases and 536 controls with 627 (75%) men, and 527 (63%) were below 40 years of age. Individual factors were the main drivers of transmission, with little contribution by environmental factors. Of the twenty individual factors, rare hand sanitizer use, travel before shift work, and social interactions outside of work increased SARS-CoV-2 transmission. Of the twenty-two environmental factors, only working in air-conditioned spaces was associated with SARS-CoV-2 transmission. Communication messages may enhance workers' individual responsibility and responsibility for the safety of others to reduce SARS-CoV-2 transmission.

Lessons from the first 6 years of an intervention-based field epidemiology training programme in Papua New Guinea, 2013-2018.

Papua New Guinea (PNG) faces a critical shortage of human resources to address pressing public health challenges arising from an increasing burden of communicable and non-communicable diseases. PNG is an independent State in the Pacific and home to 8.2 million people. Resource and infrastructure constraints due to the country's challenging geography have made it difficult and expensive to deliver health services and implement health programmes. The National Department of Health and its partners developed a field epidemiology training programme of Papua New Guinea (FETPNG) to strengthen the country's public health workforce. The training programme covers field epidemiology competencies and includes the design, implementation and evaluation of evidence-based interventions by Fellows. From 2013 to 2018, FETPNG graduated 81 field epidemiologists. Most FETPNG graduates (84%) were from provincial or district health departments or organisations. Many of their intervention projects resulted in successful public health outcomes with tangible local impacts. Health challenges addressed included reducing the burden of multi-drug resistant-tuberculosis (TB), increasing immunisation coverage, screening and treating HIV/TB patients, and improving reproductive health outcomes. FETPNG Fellows and graduates have also evaluated disease surveillance systems and investigated disease outbreaks. Early and unwavering national ownership of FETPNG created a sustainable programme fitting the needs of this low-resource country. A focus on designing and implementing effective public health interventions not only provides useful skills to Fellows but also contributes to real-time, tangible and meaningful improvements in the health of the population. The graduates of FETPNG now provide a critical mass of public health practitioners across the country. Their skills in responding to outbreaks and public health emergencies, in collecting, analysing and interpreting data, and in designing, implementing and evaluating public health interventions continues to advance public health in PNG.

Field Epidemiology and Laboratory Training Program, Where Is the L-Track?

Background: Modifications of the Field Epidemiology Training Program (FETP) curricula to include a laboratory track (L-Track), to become Field Epidemiology and Laboratory Training Program (FELTP), began in 2004 in Kenya. The L-Track offered candidates training on laboratory competencies in management, policy, quality systems, and diagnostic methods as well as epidemiology, disease surveillance and outbreak response. Since then several FELTPs have discontinued the L-Track and instead offer all candidates, epidemiologists and laboratorians, a single FETP curriculum. Reasons for these changes are reported here. Methods: A questionnaire was sent to directors of 13 FELTP programs collecting information on the status of the programs, reasons for any changes, basic entry qualifications, source institutions and where residents were post enrollment or after graduation. Data from previous CDC internal assessments on FELTP L-Track was also reviewed. Results: Out of the 13 FELTPs included, directors from 10 FELTPs sent back information on their specific programs. The FELTPs in Kenya, Mozambique, Cameroon and Kazakhstan and Mali have discontinued a separate L-Track while those in Ghana, Georgia, Nigeria, Rwanda, and Tanzania continue to offer the separate L-Track. Reasons for discontinuation included lack of standardized curriculum, unclear strategies of the separate L-Track, and funding constraints. Two countries Kenya and Tanzania reported on the career progression of their graduates. Results show 84% (Kenya) and 51% (Tanzania) of candidates in the FELTP, L-Track were recruited from national/regional medical health laboratories. However post-graduation, 56% (Kenya) and 43% (Tanzania) were working as epidemiologists, program managers, program coordinators, or regulatory/inspection boards. Professional upward mobility was high; 87% (Kenya) and 73% (Tanzania) residents, reported promotions either in the same or in new institutions. Conclusions: The FELTP L-Track residents continue to offer critical contributions to public health workforce development with high upward mobility. While this may be a reflection of professional versatility and demand of the FELTP graduates, the move from core laboratory services underscores the challenges in filling and retaining qualified staff within the laboratory systems. Results suggest different strategies are needed to strengthen laboratory management and leadership programs with a clear focus on laboratory systems and laboratory networks to meet current and future clinical and public health laboratory workforce demands.

Lessons learnt from a three-year pilot field epidemiology training programme.

PROBLEM: The Pacific region has widely dispersed populations, limited financial and human resources and a high burden of disease. There is an urgent need to improve the availability, reliability and timeliness of useable health data. CONTEXT: The purpose of this paper is to share lessons learnt from a three-year pilot field epidemiology training programme that was designed to respond to these Pacific health challenges. The pilot programme built on and further developed an existing field epidemiology training programme for Pacific health staff. ACTION: The programme was delivered in country by epidemiologists working for Pacific Public Health Surveillance Network partners. The programme consisted of five courses: four one-week classroom-based courses and one field epidemiology project. Sessions were structured so that theoretical understanding was achieved through interaction and reinforced through practical hands-on group activities, case studies and other interactive practical learning methods. OUTCOME: As of September 2016, 258 students had commenced the programme. Twenty-six course workshops were delivered and one cohort of students had completed the full five-course programme. The programme proved popular and gained a high level of student engagement. DISCUSSION: Face-to-face delivery, a low student-to-facilitator ratio, substantial group work and practical exercises were identified as key factors that contributed to the students developing skills and confidence. Close engagement of leaders and the need to quickly evaluate and adapt the curriculum were important lessons, and the collaboration between external partners was considered important for promoting a harmonized approach to health needs in the Pacific.

First pandemic A (H1N1) pdm09 outbreak in a private school, Bangkok, Thailand, June 2009.

OBJECTIVE: On June 9, 2009, the Thailand Ministry of Public Health received their first report of an outbreak of the pandemic A (HIN1) pdm09 that occurred in a school. The authors conducted a study to describe the epidemiological characteristics of the outbreak and its resurgence, estimate the basic reproduction number (R) and review recommendations for prevention and control. MATERIAL AND METHOD: Active case finding in the school and reviewing reports to the national surveillance system identified 184 students infected by the new virus. A survey described the illness in the students and the prevention and control measures taken by the school. The basic reproduction number was estimated from data in the early epidemic phase. The other survey was done to assess factors contributing to the resurgence of the outbreak. RESULTS: Students with the pandemic A (HINI) pdm09 had a mild illness resembling seasonal influenza. Overcrowding in the classroom and activities that mixed students from different classes contributed to transmission in the school. The basic reproduction number for this school-based setting is 3.58. The second outbreak occurred because of poor monitoring of absenteeism and management of ill students. CONCLUSION: This was the first outbreak ofthepandemic A (HIN1) pdm09 in Thailand. The source could not be identified. Effective control measures monitoring, screening, strict personal hygiene and proper management of ill students.

Lessons from the 2006 Louisiana health and population survey.

The 2005 hurricane season caused extensive damage and induced a mass migration of approximately 1.1 million people from southern Louisiana in the United States. Current and accurate estimates of population size and demographics and an assessment of the critical needs for public services were required to guide recovery efforts. Since forecasts using pre-hurricane data may produce inaccurate estimates of the post-hurricane population, a household survey in 18 hurricane-affected parishes was conducted to provide timely and credible information on the size of these populations, their demographics and their condition. This paper describes the methods used, the challenges encountered, and the key factors for successful implementation. This post-disaster survey was unique because it identified the needs of the people in the affected parishes and quantified the number of people with these needs. Consequently, this survey established new population and health indicator baselines that otherwise would have not been available to guide the relief and recovery efforts in southern Louisiana.

Infections and treatment of wounds in survivors of the 2004 Tsunami in Thailand.

On 26 December 2004, a tsunami devastated the west coast of Thailand and caused 8457 injuries and 5395 deaths. Data were collected from 26 December 2004 to 31 January 2005 at four public hospitals to describe the character and treatment of wounds of 523 persons who were injured during tsunami and sought medical treatment. Wounds were contaminated with mud, sand, debris and sea water and had an infection rate of 66.5% (674/1013). Most wounds (45%) had poly-microbial infection with gram-negative rods such as Escherichia coli, Klebsiella pneumoniae, Proteus and Pseudomonas species. The risk of wound infection increased with size of the wound and presence of an open fracture. Infections occurred more frequently on the lower than upper trunk of the body. Early treatment with antibiotics was protective against wound infection. Many patients asked to have their wounds sutured so that they could return to their village to look for their families and to repair damage. This report suggests that wounds should be aggressively debrided and suturing postponed if possible. Patients should be given broad spectrum antibiotics to assist with wound healing.

Flocculant-disinfectant point-of-use water treatment for reducing arsenic exposure in rural Bangladesh.

We introduced flocculant-disinfectant water treatment for 12 weeks in 103 households in Bangladesh to assess if drinking water would be chemically and microbiologically improved and the body burden of arsenic reduced. The median concentration of arsenic in tubewell water decreased by 88% after introduction of the flocculant-disinfectant from 136 microg/l at baseline to 16 (p < 0.001). The median concentration of total urinary arsenic decreased 42% from 385 microg/g creatinine at baseline to 225 microg/g creatinine after intervention (p < 0.001). Among 206 post-intervention drinking water samples that were reportedly treated on the date the sample was collected, 99 (48%) lacked residual free chlorine and 100 (49%) were contaminated with thermotolerant coliforms. The flocculant-disinfectant markedly reduced arsenic in drinking water, but treated drinking water was frequently contaminated with fecal organisms. The lesser reduction in urinary arsenic compared to water arsenic and the health consequences of this reduction require further research.

Overview of deaths associated with natural events, United States, 1979-2004.

Analysis of the National Center for Health Statistics' Compressed Mortality File showed that between 1979 and 2004, natural events caused 21,491 deaths in the United States. During this 26-year period, there were 10,827 cold-related deaths and 5,279 heat-related deaths. Extreme cold or heat accounted for 75 per cent of the total number of deaths attributed to natural events--more than all of deaths resulting from lightning, storms and foods, and earth movements, such as earthquakes and landslides. Cold-related death rates were highest in the states of Alaska, Montana, New Mexico, and South Dakota, while heat-related deaths were highest in the states of Arizona, Missouri, and Arkansas. These deaths occurred more often among the elderly and black men. Other deaths were attributed to lightning (1,906), storms and foods (2,741), and earth movements (738). Most deaths associated with natural events are preventable and society can take action to decrease the morbidity and mortality connected with them.

Serum dioxin levels in residents of Calcasieu and Lafayette parishes, Louisiana with comparison to the US population.

The Agency for Toxic Substances and Disease Registry (ATSDR) used a cross-sectional study to compare the serum dioxin toxic equivalent (TEQ) levels of a population-based representative sample of Calcasieu Parish residents aged 15 years and older to a similar group of residents of Lafayette Parish with less industrial facilities. Serum dioxins consisted of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls. Overall, the mean and distribution of serum dioxin TEQ level in residents of both parishes were similar by age groups (15-29 years, 30-44 years, 45-59 years, and 60 year and older). When the Calcasieu Parish area was further divided based on distance to three industrial areas, the mean dioxin TEQ levels were similar. Serum dioxin TEQ levels in residents of both parishes increased with age. Calcasieu Parish residents who reported having eaten locally caught fish, smoked cigarettes, worked in an occupation with potential exposure, or used pesticides had dioxin levels similar to Lafayette Parish residents who reported these activities. African Americans had higher dioxin levels than Caucasians in Lafayette Parish and both races in Calcasieu Parish. The congener profiles were similar in residents of both parishes. When the combined Calcasieu and Lafayette Parish data were compared by age group to the National Health and Nutrition Examination Survey (NHANES) 2001-2002 data, the geometric means for the dioxin levels in the combined Parish data set were significantly lower than the NHANES data in all age groups (all P-values <0.0001), except the oldest age group where the significance level is marginal (P=0.067). The various percentiles of the youngest age group of the combined parish data were also significantly lower than those in NHANES. Since the combined parish dioxin levels were below a representative sampling of the US population, there is no increase in serum dioxin concentrations in both the parishes.

Are nitrate levels in groundwater stable over time?

Epidemiologists often use a retrospective study design to examine for associations between an exposure and the occurrence of adverse health effects. Several of these studies used this approach to examine for an association between elevated levels of nitrate in drinking water and related health effects such as methemoglobinemia, cancer, neural tube effects, or spontaneous abortions. Often, data on exposures that occurred before these health outcomes were not available. Consequently, researchers use measurements of exposures at the time of the study to represent exposures that occurred before people developed these conditions. An opportunity to examine the stability of nitrate in water occurred during a survey of private water wells in nine Midwestern states. In this survey, water samples from 853 homes with drilled wells were collected in May 1994 and in September 1995 and nitrate-nitrogen (nitrate-N) was measured by the colorimetric cadmium reduction method. Nitrate-N levels from the same well over time were assessed by a mixed-effects analysis of variance. Analysis showed no significant difference in between the initial level and those measured 16 months later. Furthermore, analysis showed that most of the variance in the nitrate concentrations in well water was due to well-to-well variation (89%) rather than to residual error (12%). This observation showed that a single measurement of nitrate in water from drilled wells could represent longer periods of exposure.

Maternal exposure to polybrominated and polychlorinated biphenyls: infant birth weight and gestational age.

Understanding the influence of maternal exposures on gestational age and birth weight is essential given that pre-term and/or low birth weight infants are at risk for increased mortality and morbidity. We performed a retrospective analysis of a cohort exposed to polybrominated biphenyls (PBB) through accidental contamination of cattle feed and polychlorinated biphenyls (PCB) through residual contamination in the geographic region. Our study population consisted of 444 mothers and their 899 infants born between 1975 and 1997. Using restricted maximum likelihood estimation, no significant association was found between estimated maternal serum PBB at conception or enrollment PCB levels and gestational age or infant birth weight in unadjusted models or in models that adjusted for maternal age, smoking, parity, infant gender, and decade of birth. For enrollment maternal serum PBB, no association was observed for gestational age. However, a negative association with high levels of enrollment maternal serum PBB and birth weight was suggested. We also examined the birth weight and gestational age among offspring of women with the highest (10%) PBB or PCB exposure, and observed no significant association. Because brominated compounds are currently used in consumer products and therefore, are increasingly prevalent in the environment, additional research is needed to better understand the potential relationship between in utero exposure to brominated compounds and adverse health outcomes.