Estimate of Burden and Direct Healthcare Cost of Infectious Waterborne Disease in the United States

Provision of safe drinking water in the United States is a great public health achievement. However, new waterborne disease challenges have emerged (e.g., aging infrastructure, chlorine-tolerant and biofilm-related pathogens, increased recreational water use). Comprehensive estimates of the health burden for all water exposure routes (ingestion, contact, inhalation) and sources (drinking, recreational, environmental) are needed. We estimated total illnesses, emergency department (ED) visits, hospitalizations, deaths, and direct healthcare costs for 17 waterborne infectious diseases. About 7.15 million waterborne illnesses occur annually (95% credible interval [CrI] 3.88 million–12.0 million), results in 601,000 ED visits (95% CrI 364,000–866,000), 118,000 hospitalizations (95% CrI 86,800–150,000), and 6,630 deaths (95% CrI 4,520–8,870) and incurring US $3.33 billion (95% CrI 1.37 billion–8.77 billion) in direct healthcare costs. Otitis externa and norovirus infection were the most common illnesses. Most hospitalizations and deaths were caused by biofilm-associated pathogens (nontuberculous mycobacteria, Pseudomonas, Legionella), costing US $2.39 billion annually.     

Recency-Weighted Statistical Modeling Approach to Attribute Illnesses Caused by 4 Pathogens to Food Sources Using Outbreak Data,United States

Foodborne illness source attribution is foundational to a risk-based food safety system. We describe a method for attributing US foodborne illnesses caused by nontyphoidal Salmonella enterica, Escherichia coli O157, Listeria monocytogenes, and Campylobacter to 17 food categories using statistical modeling of outbreak data. This method adjusts for epidemiologic factors associated with outbreak size, down-weights older outbreaks, and estimates credibility intervals. On the basis of 952 reported outbreaks and 32,802 illnesses during 1998–2012, we attribute 77% of foodborne Salmonella illnesses to 7 food categories (seeded vegetables, eggs, chicken, other produce, pork, beef, and fruits), 82% of E. coli O157 illnesses to beef and vegetable row crops, 81% of L. monocytogenes illnesses to fruits and dairy, and 74% of Campylobacter illnesses to dairy and chicken. However, because Campylobacter outbreaks probably overrepresent dairy as a source of nonoutbreak campylobacteriosis, we caution against using these Campylobacter attribution estimates without further adjustment.     

Sexual Contact as Risk Factor for Campylobacter Infection,Denmark

Campylobacteriosis is a disease of worldwide importance, but aspects of its transmission dynamics, particularly risk factors, are still poorly understood. We used data from a matched case-control study of 4,269 men who have sex with men (MSM) and 26,215 controls, combined with national surveillance data on Campylobacter spp., Salmonella spp., and Shigella spp., to calculate matched odds ratios (mORs) for infection among MSM and controls. MSM had higher odds of Campylobacter (mOR 14, 95% CI 10–21) and Shigella (mOR 74, 95% CI 27–203) infections, but not Salmonella (mOR 0.2, 95% CI 0–13), and were less likely than controls to have acquired Campylobacter infection abroad (χ² = 21; p<0.001). Our results confirm that sexual contact is a risk factor for campylobacteriosis and also suggest explanations for unique features of Campylobacter epidemiology. These findings provide a baseline for updating infection risk guidelines to the general population.     

吉兰-巴雷综合征相关空肠弯曲菌的蛋白质谱特征分析

目的 分析吉兰-巴雷综合征(GBS)相关空肠弯曲菌(Cj)与非GBS相关Cj的蛋白质谱特征。方法 利用双向电泳对这两类Cj各8株菌的全菌蛋白进行分离,比较蛋白质谱之间的差异,并对差异蛋白进行基质辅助激光解吸离子化飞行时间质谱(MALDI-TOF)分析。结果 比较发现20个差异蛋白,质谱分析鉴定出17个蛋白质,包括wlaX蛋白,参与能量代谢的苹果酸脱氢酶、磷酸丙糖异构酶、镍-铁还原酶小亚单位、半胱氨酸合成酶及支链氨基酸氨基转移酶,参与细胞加工处理过程的热休克蛋白、铁吸收ABC转运系统周质铁结合蛋白、烷基过氧化氢还原酶以及与细胞表面结构有关的鞭毛蛋白、UDP-N-乙酰烯醇式丙酮酸葡萄糖胺还原酶等。结论 wlaX蛋白可能与致GBS相关脂多糖的独特结构合成或细菌的毒力有关,wlaX蛋白及鞭毛蛋白有可能为GBS相关Cj的特征蛋白。     

Motility of Campylobacter concisus isolated from saliva,feces, and gut mucosal biopsies

Campylobacter concisus is an emerging pathogen associated with gastrointestinal disorders such as gastroenteritis and inflammatory bowel diseases (IBD), but the species is also found in healthy subjects. The heterogeneous genome of C. concisus increases the likelihood of varying virulence between strains. Flagella motility is a crucial virulence factor for the well‐recognized Campylobacter jejuni; therefore, this study aimed to analyze the motility of C. concisus isolated from saliva, gut biopsies, and feces of patients with IBD, gastroenteritis, and healthy subjects. The motility zones of 63 isolates from 52 patients were measured after microaerobic growth in soft‐agar plates for 72 hours. The motility of C. concisus was significantly lower than that of Campylobacter jejuni and Campylobacter fetus subsp. fetus. The motility of C. concisus varied between isolates (4–22 mm), but there was no statistical significant difference between isolates from IBD patients and healthy subjects (p = 0.14). A tendency of a larger motility zones was observed for IBD gut mucosa isolates, although it did not reach statistical significance (p = 0.13), and no difference was found between oral or fecal isolates between groups. In conclusion, the varying motility of C. concisus could not be related to disease outcome or colonization sites.     

Motility and biofilm formation of the emerging gastrointestinal pathogen Campylobacter concisus differs under microaerophilic and anaerobic environments

Campylobacter concisus has been isolated from patients with gastroenteritis and inflammatory bowel disease (IBD), as well as healthy subjects. While strain differences may plausibly explain virulence differentials, an alternative hypothesis posits that the pathogenic potential of this species may depend on altered ecosystem conditions in the inflamed gut. One potential difference is oxygen availability, which is frequently increased under conditions of inflammation and is known to regulate bacterial virulence. Hence, we hypothesized that oxygen influences C. concisus physiology. We therefore characterized the effect of microaerophilic or anaerobic environments on C. concisus motility and biofilm formation, two important determinants of host colonization and dissemination. C. concisus isolates (n = 46) sourced from saliva, gut mucosal biopsies and feces of patients with IBD (n = 23), gastroenteritis (n = 8) and healthy subjects (n = 13), were used for this study. Capacity to form biofilms was determined using crystal violet assay, while assessment of dispersion through soft agar permitted motility to be assessed. No association existed between GI disease and either motility or biofilm forming capacity. Oral isolates exhibited significantly greater capacity for biofilm formation compared to fecal isolates (p<0.03), and showed a strong negative correlation between motility and biofilm formation (r = -0.7; p = 0.01). Motility significantly increased when strains were cultured under microaerophilic compared to anaerobic conditions (p<0.001). Increased biofilm formation under microaerophillic conditions was also observed for a subset of isolates. Hence, differences in oxygen availability appear to influence key physiological aspects of the opportunistic gastrointestinal pathogen C. concisus.     

北京部分市售整鸡中沙门菌和弯曲菌协同定量污染研究

目的对2013年北京部分市售整鸡样品中沙门菌和弯曲菌的定量污染水平、沙门菌血清型和弯曲菌种水平分布进行研究。方法 2013年5—7月采集北京市售整鸡样品33份,进行样品中沙门菌和弯曲菌的定量检测,并分别对沙门菌和弯曲菌进行血清分型和种水平鉴定。结果 19个样品检出沙门菌,检出率为57.6%;5个样品检出弯曲菌,检出率为15.2%;阳性样品中沙门菌和弯曲菌平均污染水平分别为119.4 MPN/100g和58.6 CFU/g。分离出的166株沙门菌被鉴定为14种血清型,最常见的为肠炎沙门菌,其次为印第安纳沙门菌。从同一样品中分离到共11种2个以上不同血清型组合的沙门菌,最常见的血清型组合为肠炎-印第安纳沙门菌。结论 2013年5—7月北京部分市售整鸡中沙门菌污染率较高、污染水平严重、血清型复杂。     

空肠弯曲菌全菌灭活疫苗免疫鸡效果评价北大核心CSCD

目的拟研制一种可降低空肠弯曲菌在鸡肠道内定植的全菌灭活疫苗。方法利用一种新的灭活剂H;O;与CuCl;混合物灭活空肠弯曲菌制备油佐剂灭活疫苗,免疫SPF鸡后测定灭活疫苗诱导产生的特异性抗体水平,通过口服攻毒评价疫苗免疫对空肠弯曲菌在鸡盲肠内定植的影响,同时测定盲肠细胞因子在转录水平的变化,以及对盲肠绒毛长度和隐窝深度的影响。结果制备的全菌灭活疫苗免疫SPF鸡后可诱导产生特异性血清IgG和胆汁IgA,但口服攻毒后不能抑制或降低空肠弯曲菌在盲肠内的定植水平,且对免疫鸡的盲肠绒毛长度和隐窝深度无明显影响。测定的鸡盲肠中多数细胞因子在空肠弯曲菌攻毒前与攻毒后1 d的转录水平差异不明显,而在攻毒后10 d明显上升;同日龄样品比较结果显示,部分细胞因子的表达量在佐剂对照组和全菌免疫组较空白对照组明显上调。结论本试验研制的全菌灭活疫苗虽可诱导产生高水平特异性抗体,但不能降低空肠弯曲菌在鸡盲肠内的定植水平,提示空肠弯曲菌在鸡盲肠内的定植机制需深入探究。