Human T cell responses to the ESAT-6 antigen from Mycobacterium tuberculosis

Human T cell responses to ESAT-6 and eight synthetic overlapping peptides were investigated in tuberculosis (TB) patients and control subjects from regions of high and low endemicity for TB. ESAT-6 was recognized by 65% of all tuberculin purified protein derivative-responsive TB patients, whereas only 2 of 29 bacille Calmette-Guérin-vaccinated Danish healthy donors recognized this molecule. In Ethiopia, a high frequency (58%) of healthy contacts of TB patients recognized ESAT-6. All of the peptides were recognized by some donors, indicating that the molecule holds multiple epitopes. Danish and Ethiopian patients differed in the fine specificity of their peptide responses. Recognition of the C-terminal region (aa 72-95) was predominant in Danish patients, whereas recognition of aa 42-75 was predominant in Ethiopia. The relationship of these differences to the distribution of HLA types in the two populations is discussed. This study demonstrates that ESAT-6 is frequently recognized during early infection and holds potential as a component of a future TB-specific diagnostic reagent.

Occurrence of phthalate metabolites in human urine from several Asian countries

The occurrence of 14 phthalate metabolites was found in human urine samples collected from seven Asian countries: China, India, Japan, Korea, Kuwait, Malaysia, and Vietnam. Phthalate metabolites were found in all samples, indicating widespread exposure of humans to phthalates in these Asian countries. The highest total (the sum of 14 phthalates) phthalate metabolite concentrations were found in samples collected from Kuwait (median: 1050 ng/mL), followed in decreasing order by samples from India (389 ng/mL), China (234 ng/mL), Vietnam (133 ng/mL), Japan (120 ng/mL), Korea (117 ng/mL), and Malaysia (94.9 ng/mL). The creatinine-adjusted median concentrations of total phthalates for urine samples from Kuwait, India, China, Vietnam, Japan, Korea, and Malaysia were 692, 506, 289, 119, 103, 104, and 169 μg/g creatinine, respectively. Monomethyl phthalate (mMP), monoethyl phthalate (mEP), mono (2-isobutyl phthalate) (miBP), mono-n-butyl phthalate (mBP), and metabolites of di-(2-ethylhexyl) phthalate (DEHP) were the dominant compounds, collectively accounting for >95% of the total concentrations in the samples from the seven countries. The profiles of urinary phthalate metabolite concentrations varied among the samples collected from the seven countries. Urine samples from Kuwait contained the highest concentrations of mEP (median: 391 ng/mL), mBP (94.1 ng/mL), and the metabolites of DEHP (202 ng/mL), whereas samples from China and Japan contained the highest concentrations of miBP (50.8 ng/mL) and mMP (17.5 ng/mL), respectively. mEP was the predominant metabolite in urine samples from India and Kuwait (accounting for 49% of the total), mBP and miBP were the predominant compounds in samples from China (52%), and DEHP metabolites were the predominant compounds in samples from Korea (46%) and Vietnam (52%). Based on the urinary concentrations of mEP, mBP, miBP, and DEHP metabolites of the samples from the seven Asian countries, we estimated daily intake rates of diethyl phthalate (DEP), dibutyl phthalate (DBP), and DEHP. The results indicated that people in the seven Asian countries are exposed to DEP, DBP, and DEHP at levels well below the reference doses (RfD) suggested as unsafe by the U.S. Environmental Protection Agency (EPA). The estimated exposure doses to DEHP in Kuwait, however, were above the RfD recommended by the EPA.

Levels and profiles of organochlorines and flame retardants in car and house dust from Kuwait and Pakistan: implication for human exposure via dust ingestion

There are only few studies documenting indoor pollution in the Middle East and the Indian subcontinent. In present study, we have evaluated the occurrence of various organochlorines (OCs) and flame retardants (FRs) in dust from cars and houses of Pakistan and Kuwait. Polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), organophosphate FRs (PFRs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were investigated in indoor dust from urban houses (N=15 per country) and cars (N=15 per country). PFRs were the major analytes in all four microenvironments, followed by PBDEs>NBFRs>OCPs>PCBs. For all classes of analytes, relatively lower levels were observed in car and house dust from Pakistan than Kuwait. Levels of ∑PBDEs, ∑NBFRs and ∑PFRs were higher in car dust, while ∑OCPs and ∑PCBs were higher in house dust from both countries. ∑PFRs occurred at average concentrations of 16,900, 87,900, 475, and 2500ng/g in Kuwaiti house and car, and Pakistani house and car dust, respectively. For both countries, the profiles of analytes in car dust were different from those in the house dust. Different exposure scenarios using 5th percentile, median, mean, and 95th percentile levels were estimated for adult, taxi drivers and toddlers. For Kuwaiti toddlers, assuming high dust intake and mean and 95th percentile concentrations, the values computed for ∑OCPs (1500ng/kg bw/day) were higher than RfD values, while for ∑PCBs (14.5ng/kg bw/day) it was only two-fold lower than the corresponding RfDs.

'The honeymoon phase' in children with type 1 diabetes mellitus: frequency, duration, and influential factors

BACKGROUND

The honeymoon period (i.e., partial remission) of type 1 diabetes mellitus is characterized by reduced insulin requirements while good glycemic control is maintained. The clinical significance is the potential possibility for pharmacological intervention during this period to either slow down or arrest the ongoing destruction of the remaining beta-cells.

METHODS

A group of 103 diabetic children, younger than 12 yr of age, were prospectively studied to assess the frequency, duration, and factors that may affect partial remission. At the time of admission, patients were characterized by age, gender, symptom duration, diabetic ketoacidosis (DKA), and blood sugar level at admission. The honeymoon period was defined as a period with insulin requirements of less than 0.5 U/kg/day and hemoglobin A1c (HbA1c) level of less or equal to 6%.

RESULTS

Partial remission occurred in 71, being complete in three. The length of time until remission was 28.6 +/- 12.3 (mean +/- SD) days. The duration of remission was 7.2 +/- 4.8 months. Remission rates were higher in those patients older than 5 yr compared with those between 3 and 5 yr of age. DKA at presentation and long duration of symptoms were associated with lower duration of remission (p < 0.001 and p < 0.001, respectively). Children in whom remission occurred had significantly lower blood glucose levels and higher pH at presentation (p < 0.001 and p < 0.001, respectively).

CONCLUSIONS

Young age and severe disease at presentation are associated with decreased residual beta-cells function that is reflected by a lower incidence of partial remission. These observations are important to consider in the research regarding therapies that will have the potential goal to induce prolonged and/or complete remission at disease onset or shortly thereafter.

Acceptance of a COVID-19 Vaccine and Its Related Determinants among the General Adult Population in Kuwait

OBJECTIVE

The objective of this study was to determine the acceptance of a coronavirus disease 2019 (COVID-19) vaccine among the general adult population in Kuwait and assess its determinants.

SUBJECTS AND METHODS

A web-based cross-sectional study was conducted by enrolling adults living in Kuwait (n = 2,368; aged ≥21 years). Acceptance of a COVID-19 vaccine was inferred if participants indicated that they "definitely or probably will accept vaccination against COVID-19 once a vaccine is available." Associations were explored by applying a modified Poisson regression to estimate and infer adjusted prevalence ratios (aPR) and their 95% confidence intervals (CI).

RESULTS

In total, 53.1% (1,257/2,368) of the participants were willing to accept a COVID-19 vaccine once available. Male subjects were more willing to accept a COVID-19 vaccine than females (58.3 vs. 50.9%, p < 0.001). Subjects who viewed vaccines in general to have health-related risks were less willing to accept vaccination (aPR = 0.39, 95% CI: 0.35-0.44). Moreover, participants who previously received an influenza vaccine were more likely to accept a COVID-19 vaccine (aPR = 1.44, 95% CI: 1.31-1.58). Willingness to get vaccinated against COVID-19 increased as the self-perceived chances of contracting the infection increased (p < 0.001).

CONCLUSION

Overall, 53.1% of the study participants demonstrated willingness to get vaccinated against COVID-19. We found several factors influencing the level of acceptance. Since vaccination appears to be an essential preventive measure that can halt the COVID-19 pandemic, factors relating to low vaccine acceptance need to be urgently addressed by public health strategies.

Complete genome characterisation of a novel 26th bluetongue virus serotype from Kuwait

Bluetongue virus is the "type" species of the genus Orbivirus, family Reoviridae. Twenty four distinct bluetongue virus (BTV) serotypes have been recognized for decades, any of which is thought to be capable of causing "bluetongue" (BT), an insect-borne disease of ruminants. However, two further BTV serotypes, BTV-25 (Toggenburg orbivirus, from Switzerland) and BTV-26 (from Kuwait) have recently been identified in goats and sheep, respectively. The BTV genome is composed of ten segments of linear dsRNA, encoding 7 virus-structural proteins (VP1 to VP7) and four distinct non-structural (NS) proteins (NS1 to NS4). We report the entire BTV-26 genome sequence (isolate KUW2010/02) and comparisons to other orbiviruses. Highest identity levels were consistently detected with other BTV strains, identifying KUW2010/02 as BTV. The outer-core protein and major BTV serogroup-specific antigen "VP7" showed 98% aa sequence identity with BTV-25, indicating a common ancestry. However, higher level of variation in the nucleotide sequence of Seg-7 (81.2% identity) suggests strong conservation pressures on the protein of these two strains, and that they diverged a long time ago. Comparisons of Seg-2, encoding major outer-capsid component and cell-attachment protein "VP2" identified KUW2010/02 as 26th BTV, within a 12th Seg-2 nucleotype [nucleotype L]. Comparisons of Seg-6, encoding the smaller outer capsid protein VP5, also showed levels of nt/aa variation consistent with identification of KUW2010/02 as BTV-26 (within a 9th Seg-6 nucleotype - nucleotype I). Sequence data for Seg-2 of KUW2010/02 were used to design four sets of oligonucleotide primers for use in BTV-26, type-specific RT-PCR assays. Analyses of other more conserved genome segments placed KUW2010/02 and BTV-25/SWI2008/01 closer to each other than to other "eastern" or "western" BTV strains, but as representatives of two novel and distinct geographic groups (topotypes). Our analyses indicate that all of the BTV genome segments have evolved under strong purifying selection.

Complex factors in the etiology of Gulf War illness: wartime exposures and risk factors in veteran subgroups

BACKGROUND

At least one-fourth of U.S. veterans who served in the 1990-1991 Gulf War are affected by the chronic symptomatic illness known as Gulf War illness (GWI). Clear determination of the causes of GWI has been hindered by many factors, including limitations in how epidemiologic studies have assessed the impact of the complex deployment environment on veterans' health.

OBJECTIVE

We sought to address GWI etiologic questions by evaluating the association of symptomatic illness with characteristics of veterans' deployment.

METHODS

We compared veteran-reported wartime experiences in a population-based sample of 304 Gulf War veterans: 144 cases who met preestablished criteria for GWI and 160 controls. Veteran subgroups and confounding among deployment variables were considered in the analyses.

RESULTS

Deployment experiences and the prevalence of GWI differed significantly by veterans' location in theater. Among personnel who were in Iraq or Kuwait, where all battles took place, GWI was most strongly associated with using pyridostigmine bromide pills [odds ratio (OR) = 3.5; 95% confidence interval (CI): 1.7, 7.4] and being within 1 mile of an exploding SCUD missile (OR = 3.1; 95% CI: 1.5, 6.1). For veterans who remained in support areas, GWI was significantly associated only with personal pesticide use, with increased prevalence (OR = 12.7; 95% CI: 2.6, 61.5) in the relatively small subgroup that wore pesticide-treated uniforms, nearly all of whom also used skin pesticides. Combat service was not significantly associated with GWI.

CONCLUSIONS

Findings support a role for a limited number of wartime exposures in the etiology of GWI, which differed in importance with the deployment milieu in which veterans served.

Psychiatric diagnoses in historic and contemporary military cohorts: combat deployment and the healthy warrior effect

Research studies have identified heightened psychiatric problems among veterans of Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF). However, these studies have not compared incidence rates of psychiatric disorders across robust cohorts, nor have they documented psychiatric problems prior to combat exposure. The authors' objectives in this study were to determine incidence rates of diagnosed mental disorders in a cohort of Marines deployed to combat during OIF or OEF in 2001-2005 and to compare these with mental disorder rates in two historical and two contemporary military control groups. After exclusion of persons who had been deployed to a combat zone with a preexisting psychiatric diagnosis, the cumulative rate of post-OIF/-OEF mental disorders was 6.4%. All psychiatric conditions except post-traumatic stress disorder occurred at a lower rate in combat-deployed personnel than in personnel who were not deployed to a combat zone. The findings suggest that psychiatric disorders in Marines are diagnosed most frequently during the initial months of recruit training rather than after combat deployment. The disproportionate loss of psychologically unfit personnel early in training creates a "healthy warrior effect," because only those persons who have proven their resilience during training remain eligible for combat.

Consanguinity among the Kuwaiti population

A total of 5,007 Kuwaitis were ascertained to study the incidence of consanguineous marriages during 1983. The rate of consanguineous mating was found to be 54.3% with estimated population incidence rates 52.9 to 55.7%. First cousin marriages were the most frequent type. The average inbreeding coefficient was 0.0219 which could be considered high.

Toxic trace elements in the hair of children with autism

Excess or deficiency of natural trace elements has been implicated in the etiology of autism. This study explores whether concentration levels of toxic metals in the hair of children with autism significantly differ from those of age- and sex-matched healthy controls. In-hair concentration levels of antimony, uranium, arsenic, beryllium, mercury, cadmium, lead and aluminum from 40 boys with autism and 40 healthy boys were determined by Perkin-Elmer mass spectrometry. The children with autism had significantly (p<0.001) higher in-hair concentration levels of lead, mercury and uranium. There was no significant difference between the two groups in the other five toxic elements. The ratio between nutritional elements and toxic metals among children with autism was within the normal range. The possible sources of the toxic metals are discussed. Such testing is informative but at present the practical implications in terms of diagnosis and clinical management are limited.

Association between normative and self-perceived orthodontic treatment need among Arab high school students

The aim of this study was to investigate whether there was an association between normative and self-perceived orthodontic treatment need, and to evaluate the influence of sex and socioeconomic background on treatment need. A total of 139 high school students, aged 14 to 18 years, from 2 districts in Kuwait were included. The study consisted of a questionnaire and a clinical examination. Normative need for treatment was assessed clinically by using the index of orthodontic treatment need (IOTN). Both the dental health component (DHC) and the aesthetic component (AC) of the IOTN correlated positively with self-perceived treatment need. In 53% of the subjects, there was agreement between self-perceived treatment need and the DHC score. Between the AC component and self-perceived need, the agreement was 77%. The odds of self-perceived treatment need were 10-fold for subjects having AC scores higher than 4, indicating moderate or definite need. Sex and socioeconomic factors did not significantly affect the normative treatment need. These results suggest that the AC component of the IOTN clearly reflects the self-perceived need for treatment.

Monitoring of Pesticide Residues in Commonly Used Fruits and Vegetables in Kuwait

The presence of pesticide residues in primary and derived agricultural products raises serious health concerns for consumers. The aim of this study was to assess the level of pesticide residues in commonly consumed fruits and vegetables in Kuwait. A total of 150 samples of different fresh vegetables and fruits were analyzed for the presence of 34 pesticides using the quick easy cheap effective rugged and safe (QuEChERS) multi-residue extraction, followed by gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS). Pesticide residues above the maximum residue limits (MRL) were detected in 21% of the samples and 79% of the samples had no residues of the pesticides surveyed or contained residues below the MRL. Multiple residues were present in 40% of the samples with two to four pesticides, and four samples were contaminated with more than four pesticide residues. Of the pesticides investigated, 16 were detected, of which imidacloprid, deltamethrin, cypermethrin, malathion, acetamiprid, monocrotophos, chlorpyrifos-methyl, and diazinon exceeded their MRLs. Aldrin, an organochlorine pesticide, was detected in one apple sample, with residues below the MRL. The results indicate the occurrence of pesticide residues in commonly consumed fruits and vegetables in Kuwait, and pointed to an urgent need to develop comprehensive intervention measures to reduce the potential health risk to consumers. The need for the regular monitoring of pesticide residues and the sensitization of farmers to better pesticide safety practices, especially the need to adhere to recommended pre-harvest intervals is recommended.

Pesticide Knowledge and Safety Practices among Farm Workers in Kuwait: Results of a Survey

The unsafe and indiscriminate use of pesticides in agriculture represents a major hazard to the environment and human health. The aim of this study was to assess the levels of knowledge, attitude and practices of Kuwaiti farmers regarding the safe use of pesticides. A total of 250 farmers participated in this study through in-depth interviews and observations on-farm. The majority of the farmers acknowledged that pesticides were harmful to their health (71%) and the environment (65%). However, farmers’ level of knowledge of pesticide safety is insufficient. Over 70% of the farmers did not read or follow pesticide label instructions, and 58% did not use any personal protective equipment (PPE) when handling pesticides. Educated farmers were significantly more likely to use PPE compared with famers with limited formal education (χ² = 9.89, p < 0.05). Storage of pesticides within living areas was reported by 20% of farmers. When disposing of pesticide wastes, respondents adopted unsafe practices such as discarding, incinerating, or burying empty pesticide containers on-farm, or reusing the containers. Farmers also reported disposing leftover pesticide solution or old pesticide stocks on-farm or in the sewer. A significant number (82%) of the farmers reported at least one symptom of acute pesticide poisoning. Although farmers’ knowledge of pesticide hazards was high, the reported safety measures were poor. Comprehensive intervention measures to reduce the health and environmental risks of pesticides are needed, including pesticide safety training programs for farmers, stringent enforcement of pesticide laws, and promoting integrated pest management and non-synthetic methods of pest control.

Risk Indicators for Tooth Loss Due to Periodontal Disease

BACKGROUND

Several risk indicators for periodontal disease severity have been identified. The association of these factors with tooth loss for periodontal reasons was investigated in this cross-sectional comparative study.

METHODS

All extractions performed in 21 general dental practice clinics (25% of such clinics in Kuwait) over a 30-day period were recorded. Documented information included patient age and gender, medical history findings, dental maintenance history, toothbrushing frequency, types and numbers of extracted teeth, and the reason for the extraction. Reasons were divided into periodontal disease versus other reasons in univariate and binary logistic regression analyses.

RESULTS

A total of 1,775 patients had 3,694 teeth extracted. More teeth per patient were lost due to periodontal disease than for other reasons (2.8 +/- 0.2 versus 1.8 +/- 0.1; P <0.001). Factors significantly associated with tooth loss due to periodontal reasons in logistic regression analysis were age >35 years (odds ratio [OR] 3.45; 95% confidence interval [CI] 2.79 to 4.26), male gender (OR 1.42; 95% CI 1.17 to 1.73), never having periodontal maintenance (OR 1.48; 95% CI 1.23 to 1.78), never using a toothbrush (OR 1.81; 95% CI 1.49 to 2.20), current or past smoking (OR 1.56; 95% CI 1.28 to 1.91), anterior tooth type (OR 3.23; 95% CI 2.57 to 4.05), and the presence of either of the following medical conditions: diabetes mellitus (OR 2.64; 95% CI 2.19 to 3.18), hypertension (OR 1.73; 95% CI 1.41 to 2.13), or rheumatoid arthritis (OR 4.19; 95% CI 2.17 to 8.11).

CONCLUSION

Tooth loss due to periodontal disease is associated with the risk indicators of age, male gender, smoking, lack of professional maintenance, inadequate oral hygiene, diabetes mellitus, hypertension, rheumatoid arthritis, and anterior tooth type.

Validation of the Hospital Anxiety and Depression Scale in Arab patients

The Hospital Anxiety and Depression Scale (HADS) was administered to psychiatric outpatients with various diagnoses to assess its validity. The study was also designed to find out whether HADS can differentiate between diagnostic groups based on depression and anxiety symptoms. HADS was able to discriminate patients from controls at a sensitivity of 79% and specificity of 87%. HADS was much less sensitive, specific and diagnostically accurate in identifying anxiety and depressive disorders in the experimental group at a cut-off point of 13 and 10 respectively for both conditions. Possible psychological, social and psychiatric reasons for the results are discussed.

Brucella arthritis: a study of 96 cases in Kuwait

Of 400 patients with brucellosis, 104 (26%) had arthritis, of whom 96 could be followed up. The systemic disease in the 96 patients was acute in 54 (56%), subacute in 24 (25%), and chronic in 18 (19%). The main presenting symptoms were joint pain, fever, sweating, and easy fatigability. The joints most commonly affected were the sacroiliac joint (26%) and knee (25%) followed by hip (18%) and spine (8%). There was no particular pattern of joint affection in relation to age. Joint effusion occurred in 32/104 (30%) of cases, predominantly (94%) in the acute group. Culture of synovial fluid was negative in all, and analysis of synovial fluid for cellular profile, glucose, and protein content was not particularly helpful in diagnosis. Plain radiographs did not show major pathological changes. Among the laboratory tests, including haematological and liver function tests, the brucella enzyme linked immunosorbent assay (ELISA) was the most reliable in the diagnosis of disease, using serum and synovial fluid specimens. Treatment with a combination of streptomycin plus tetracyclines or rifampicin resulted in an excellent cure rate and resolution of arthritis without sequelae or mortality. Thus brucellosis should be considered in the differential diagnosis of arthritis, especially in areas in which the disease is endemic.

Responses to exercise, fluid, and energy balances during Ramadan in sedentary and active males

This study compares the effects of the Ramadan fast (RF) on body and plasma compositions, hematology, and responses to steady state submaximal exercise in six physically active (A, 35.5+/-1.6 y) and seven sedentary (S, 37.6+/-2.3 y) Kuwaiti men. Subjects were evaluated: 1) 1 wk before RF (pre-RF); 2) 2 wk after the start of RF (mid-RF); 3) at the 4th wk of RF (end-RF). Total body weight and body fat decreased insignificantly (<1.5%, P>0.3) in both groups. At the end of Ramadan, significant increases in osmolarity (P<0.05), Na (P<0.05) and bicarbonate (P<0.05), and a decrease in serum iron were noted in sedentary but not in active subjects. Platelet count was lower in both groups by the end of RF (P<0.05). Body weight and percent fat changed little (<1.5%) in either group. During RF, submaximal exercise heart rate declined insignificantly in group S but significantly (P<0.05) in group A. The respiratory exchange ratio R during steady state submaximal exercise decreased markedly (P<0.001) by the end of RF in both groups. It is concluded that energy balance is well maintained during RF both in S and in A subjects. Metabolic adaptations during RF result in lower exercise R due to increased lipid usage. Deficits or redistribution of specific micronutrients (iron, vitamins) may account for reductions in serum iron and platelet counts, particularly in sedentary subjects that need to limit intake to maintain body weight. The decrease in submaximal exercise heart rate indicates that during RF, cardiovascular adaptation to conditioning is adequate in the more physically active group. Body fluid balance was better maintained in active than in sedentary subjects.

Pesticide risk behaviors and factors influencing pesticide use among farmers in Kuwait

The widespread overuse of pesticides in agriculture has generated increasing concerns about the negative effects of pesticides on human health and the environment. Understanding farmers' perceptions of risk of pesticides and the determinants of pesticide overuse is important to modifying their behavior towards reducing pesticide use. A survey of 250 randomly selected smallholder vegetable farmers in Kuwait was conducted to quantify the extent of pesticide use, their pesticide risk perceptions and factors influencing their pesticide use behaviors. The majority of the farmers perceived pesticides pose some risk to the environment (65%) and human health (70.5%), while younger farmers were more likely to perceive this risk than older farmers. When asked to rate how risky pesticides were regarding several aspects of human health and the environment on a scale of 1(not risky) to 5 (extremely risky), concern was highest for the health of applicators (x̅=4.28) and lowest for air quality (x̅=2.32). The risk perceptions of the farmers did not have a positive influence on their pesticide use practices. A total of 76 pesticide active ingredients were found in use, and 9% of these belong to the WHO toxicity class II (moderately hazardous). On average, farmers applied 12.8kg of active ingredients per hectare per year, and 58% of the farmers were found to have overused pesticides, with an average overuse rate of 2.5kg. Pesticide application frequency ranged from two times a month up to once a week, depending on the crop. A binary probit model reveals that farmers' inadequate knowledge of pesticides, the influence of pesticide retailers and lack of access to non-synthetic methods of pest control are positively associated with pesticide overuse, while the propensity to overuse decreases with higher levels of education, training in Integrated Pest Management (IPM) and the safe use and handling of pesticides, and access to extension support. Comprehensive intervention measures for reducing pesticide overuse and limit the health and environmental hazards caused by pesticides are provided in this paper.

Dust storms and the risk of asthma admissions to hospitals in Kuwait

OBJECTIVE

Arid areas in the Arabian Peninsula are one of the largest sources of global dust, yet there is no data on the impact of this on human health. This study aimed to investigate the impact of dust storms on hospital admissions due to asthma and all respiratory diseases over a period of 5 years in Kuwait.

METHODS

A population-based retrospective time series study of daily emergency asthma admissions and admissions due to respiratory causes in public hospitals in Kuwait was analyzed in relation to dust storm events. Dust storm days were defined as the mean daily PM(10)>200 μg/m(3) based on measurements obtained from all six monitoring sites in the country.

FINDINGS

During the five-year study period, 569 (33.6%) days had dust storm events and they were significantly associated with an increased risk of same-day asthma and respiratory admission, adjusted relative risk of 1.07 (95% CI: 1.02-1.12) and 1.06 (95% CI: 1.04-1.08), respectively. This was particularly evident among children.

CONCLUSION

Dust storms have a significant impact on respiratory and asthma admissions. Evidence is more convincing and robust compared to that from other geographical settings which highlights the importance of public health measures to protect people's health during dust storms and reduce the burden on health services due to dust events.

A review of microplastic distribution in sediment profiles

The growing use of plastic and their indiscriminate disposal into the environment has resulted in the accumulation of huge quantities of microplastic (MP) in the marine environment. Several studies have investigated the pathways of MPs reaching marine environments and a few have begun looking at their inventories in sediment profiles. Recent estimates suggest between 70 and 90% of the MP particles are accumulated into sediment profiles. This paper reviews MPs in sediment cores, and the methods used for chronological reconstruction to provide evidence to link the plastic usage and MP inventories over time. In one example, a ²¹⁰Pb dated sediment core from Kuwait Bay revealed 0.1 MPs g^-1 of sediment deposited in approximately 1951 and 0.5 MPs g^-1 in sediment from 2009 indicating a progressively increasing presence in recent sediments. The review also highlights the issue of very large spatio-temporal variation in MP concentrations, indicating the limitation of a snapshot study especially when dealing with the surface sediments; and it demonstrates the relevance of using sediment cores for a better assessment of MP input and inventories in the marine environment. It is proposed that MP sediment data should be reported as N m^-2 year^-1 or g m^-2 year^-1, and cores preferably dated using ²¹⁰Pb, and supported by at least one other stratigraphic marker to enhance the usefulness of these datasets, since ²¹⁰Pb can reliably date sediments as old as 100 years, a time-span which extends well beyond the time plastic production began. The anomalies in data processing and reporting in terms of number per kg of sediment or per cm²/m² should be addressed essentially by adopting a standardized protocol.

House dust as a source of human exposure to polybrominated diphenyl ethers in Kuwait

This study reports concentrations of polybrominated diphenyl ethers (PBDEs) in dust samples collected from 17 homes in Kuwait. PBDEs were measured in all homes investigated with mean summation operatorPBDEs concentration ranging from 1 to 393 ng g(-1), with a geometric mean of 76 ng g(-1). The dominant congener in all samples was BDE 209 constituting ca. 85% of the summationPBDEs followed by BDE 99 (5%), BDE 47 (4.5%), and BDE 183 (2%). The congener mixture in dust is dominated by those in deca and penta formulations. Using the measured concentrations and estimates of dust ingestion rates for children and adults, estimated human non-dietary exposure based on mean PBDE levels were 14.8 and 1.5 ng day(-1) for children and adults, respectively. The 10-fold difference in exposure estimates between children and adults in this study supports previous reports that children are at greater risk from pollutants that accumulate indoors. The ubiquitous distribution of these chemicals as noted in this study highlights the fact that we are continuously exposed to low doses of chemicals in the indoor environment.

Basic gait parameters: a comparison of reference data for normal subjects 20 to 29 years of age from Kuwait and Scandinavia

This study obtained measurements of the spatiotemporal gait parameters of healthy young adult Kuwaiti subjects from both genders and compared the data to those collected in a similar study performed in Sweden. Thirty healthy subjects volunteered to participate in the study (which included being asked to walk at their "free," "slow," and "fast" self-selected speeds). We collected the spatiotemporal gait data using an automated system. Descriptive statistics were calculated for each variable measured at each walking condition. The data were then compared to those from the Swedish study. The results indicate several significant differences between Kuwaiti and Swedish subjects in their manner of walking. These results suggest a need to include data from subjects with diverse cultural backgrounds when a database on normal gait is developed or a need to limit the results of the database to a specified ethnic population.

Vitamin D status of mothers and their neonates in Kuwait

BACKGROUND

There has been a resurgence of nutritional rickets in children in many developing countries and some of the developed countries. Children between 6 and 18 months old are commonly affected. In order to find out the association between vitamin D and rickets we studied the vitamin D status of the neonates and their mothers in Kuwait.

METHODS

Two hundred and fourteen full-term pregnant mothers and their neonates were selected from two hospitals in Kuwait. All mothers had normal vaginal delivery. On the day of delivery 2.5 mL of maternal blood and 2.5 mL of cord blood samples were withdrawn. Serum 25-hydroxyvitamin D (25OHD) was determined in duplicate by radioimmunoassay using an Incstar kit. Quality control analyses were done using several between and within run experiments.

RESULTS

A total of 128 mother-neonate pairs were selected from the Al-Adan hospital and 86 from the Maternity Hospital. The mean age and parity of the mothers were similar in both hospitals. The mean (+/- SD) 25OHD levels of the mothers and the neonates in the Adan hospital were 13.3 (6.5) ng/mL and 8.2 (6.5) ng/mL, respectively. The corresponding values in the Maternity Hospital were 17.6 (12.4) and 8.1 (7.3) ng/mL for the mothers and the neonate, respectively. Serum 25OHD of the mothers and their newborn infants were highly correlated (r = 0.790, P < 0.001).

CONCLUSIONS

Results demonstrate that 40% of the mothers and 60% of the neonates are vitamin D deficient on the day of delivery. The vitamin D of the mothers and neonates are highly correlated (r = 0.790, P < 0.001).