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PubMed2002

Current molecular epidemiology and human parvovirus B19 infection.

Viruses evolve gradually through replication. Therefore, isolates of a virus species can have different genome sequences, albeit slightly, if isolates are epidemiologically unrelated. The difference in virus genome involves difference in virus functions and clinical manifestations of virus infection. Molecular epidemiology of virus infection is a relatively new field directed at infection in humans but not other animals. Analyses are based on genomic differences between virus strains with advances in methodology related to DNA analyses, progress is being made. Classification of virus strains, tracing of transmission of a strain, analyses of outbreaks (including nosocomial infection), and analyses of pathogenesis of virus infection in humans (a natural host) are given attention in molecular epidemiological studies. Human parvovirus B19 is a common human pathogen associated with a wide variety of diseases, including erythema infectiosum, aplastic crisis, hydrops fetalis, and arthritis. B19 is not propagatable in conventional cell lines, hence, molecular cloning of B19 DNA directly from clinical materials has to be done. Events concerning B19 infection were analyzed based on the concept of molecular epidemiology and studies proved to be productive to better understand the pathogenesis of B19 infection.

Cloning, Molecular↗

PubMed1964

TAXONOMY OF CLOSTRIDIUM BIFERMENTANS AND CLOSTRIDIUM SORDELLII. I. THEIR TOXIGENICITY, UREASE ACTIVITY, AND SPORULATING POTENCY.

Nishida, S. (Kanazawa University, Kanazawa, Japan), K. Tamai, and T. Yamagishi. Taxonomy of Clostridium bifermentans and Clostridium sordellii. I. Their toxigenicity, urease activity, and sporulating potency. J. Bacteriol. 88:1641-1646. 1964.-Strains with properties similar to those of Clostridium bifermentans were usually obtained by selecting heat-resistant substrains of C. sordellii 1734. Heat-resistant substrains obtained from seven other strains were also found to be nontoxic. Some of these heat-resistant substrains produced urease, but others did not. Substrains of typical cultures of C. sordellii thus can yield either substrains resembling nonpathogenic strains of C. sordellii culturally, or substrains resembling C. bifermentans. The sporulating potency of pathogenic and nonpathogenic strains of C. sordellii and strains of C. bifermentans proved to be significantly distinct. The sporulating potency of C. bifermentans was high, that of pathogenic strains of C. sordellii was low, and that of nonpathogenic strains of C. sordellii was intermediate between the other two.

Antitoxins↗

PubMed2003

Limitations of TaqMan PCR for detecting divergent viral pathogens illustrated by hepatitis A, B, C, and E viruses and human immunodeficiency virus.

Recent events illustrate the imperative to rapidly and accurately detect and identify pathogens during disease outbreaks, whether they are natural or engineered. Particularly for our primary goal of detecting bioterrorist releases, detection techniques must be both species-wide (capable of detecting all known strains of a given species) and species specific. Due to classification restrictions on the publication of data for species that may pose a bioterror threat, we illustrate the challenges of finding such assays using five nonthreat organisms that are nevertheless of public health concern: human immunodeficiency virus (HIV) and four species of hepatitis viruses. Fluorogenic probe-based PCR assays (TaqMan; Perkin-Elmer Corp., Applied Biosystems, Foster City, Calif.) may be sensitive, fast methods for the identification of species in which the genome is conserved among strains, such as hepatitis A virus. For species such as HIV, however, the strains are highly divergent. We use computational methods to show that nine TaqMan primer and probe sequences, or signatures, are needed to ensure that all strains will be detected, but this is an unfeasible number, considering the cost of TaqMan probes. Strains of hepatitis B, C, and E viruses show intermediate divergence, so that two to three TaqMan signatures are required to detect all strains of each virus. We conclude that for species such as hepatitis A virus with high levels of sequence conservation among strains, signatures can be found computationally for detection by the TaqMan assay, which is a sensitive, rapid, and cost-effective method. However, for species such as HIV with substantial genetic divergence among strains, the TaqMan assay becomes unfeasible and alternative detection methods may be required. We compare the TaqMan assay with some of the alternative nucleic acid-based detection techniques of microarray, chip, and bead technologies in terms of sensitivity, speed, and cost.

Computational Biology↗

PubMed2001

Redescription and systematic status of Capillaria philippinensis, an intestinal parasite of human beings.

A redescription of the capillariid originally described as Capillaria philippinensis, a pathogenic intestinal parasite of humans, is provided on the basis of specimens collected in humans in the Philippines. The general morphology, particularly the structure of the male caudal end, shows that this species belongs to Paracapillaria Mendonça, 1963 according to the present classification system of capillariids; the species is transferred to Paracapillaria as Paracapillaria philippinensis (Chitwood, Velasquez, and Salazar, 1968) n. comb. Crossicapillaria n. subgen. is proposed to accommodate this species.

Animals↗

PubMed1987

[Aneurysms of the infrarenal aorta and visceral cancer. Therapeutic problems].

The association of an abdominal aortic aneurysm (AAA) and a long-standing or progressing cancer is a frequent finding: 14 cases among the 112 infrarenal aortic aneurysms treated by one of us (J.C.) are discussed in this report. The marked predominance in bronchial and ORL epithelioma (50%) is explained by the common pathogenic factors of these neoplasms and atheroma. Surgical treatment is difficult because of the potentially lethal character of the two lesions: it must allow for size and possible progressive nature of aneurysm and prognosis of the neoplasm as defined by the TNM classification. Detection of an AAA in a patient with a history of neoplasm means that the opportunity for aortic surgery is dependent of therapeutic control (or otherwise) of the neoplastic disease and therefore frequently the length of follow up period after therapy. When detection of the AAA and neoplasm is simultaneous, the aneurysm progressing or ruptured, surgical complications leave little choice with regard to operative strategy. In 3 cases, simultaneous treatment of an AAA and a neoplasm was possible, particularly in the case of Grawitz tumors of cortical development without pyelocaliceal invasion. In most patients, separate operative stages are necessary in order to ensure asepsis of AAA surgery. Aneurysmal occlusion with an extrafocal shunt can allow one-stage surgery when aneurysm and neoplasm are equally menacing.

Aged↗

PubMed1983

Chronic granulomatous disease: a syndrome of phagocyte oxidase deficiencies.

Chronic granulomatous disease (CGD) is an inherited disorder of host defense due to the inability of the phagocyte to generate toxic oxygen metabolites upon appropriate stimulation. The disorder is heterogeneous even within the confines of a defective respiratory burst oxidase function, and may arise from a biochemical lesion at either the receptor, the activating pathways or the enzyme level. The identification of defects in plasma membrane depolarization, missing cytochrome and abnormal enzymatic function has yielded new insights into the pathophysiologic basis of CGD. A classification of this syndrome based on more precise biochemical criteria is proposed, which defines the disease as distinct from other associated enzymopathies with similar pathology and emphasizes the metabolic basis of the pathophysiologic defect in phagocyte function. Review of the clinical manifestations, pathogenic organisms and natural course of the disease, emphasizes the critical role of the oxidative metabolism of the normal neutrophil and offers a perspective on oxygen free radical biochemistry in the inflammatory response.

Adolescent↗

PubMedDate not supplied

Reclassifying the pathogenesis of rheumatoid arthritis: from the susceptibility to the degenerative stages.

Rheumatoid arthritis is a heterogeneous disease in which different pathogenic mechanisms have been suggested. Recent advances in immunology and immunogenetics have contributed to a better understanding of this complex illness. Several stages have been previously described, based on clinical and radiological findings, and proposing different therapeutic options. We have analysed previous classification schema, making some changes and incorporating new knowledge. Our classification system includes a susceptibility stage and a degenerative stage. Therapeutic options are described for each stage. We hope that this will provide useful guidelines in the future for clinicians and researchers.

Arthritis, Rheumatoid↗

PubMed1987

Norfloxacin, a fluoroquinolone antibacterial agent. Classification, mechanism of action, and in vitro activity.

Norfloxacin is an orally absorbed fluoroquinolone antibacterial with a fluorine at position 6 and a piperazine ring at position 7. These changes have resulted in a marked enhancement (compared with that of the older quinolones) of in vitro antibacterial activity. Specifically, the antibacterial spectrum of norfloxacin includes Pseudomonas aeruginosa, as well as enteric pathogens. Norfloxacin is also active against both penicillin-susceptible and penicillin-resistant strains of Neisseria gonorrhoeae. Relative to its activity against gram-negative bacteria, norfloxacin is somewhat less active against gram-positive cocci. In general, the staphylococci are more susceptible to the drug than are the streptococci. As with all fluoroquinolones, norfloxacin's activity against anaerobic bacteria is poor. For urinary tract bacterial isolates, the following Bauer-Kirby disk diffusion zone-size breakpoints have been proposed: greater than or equal to 17 mm, susceptible; 13 to 16 mm, intermediate; less than or equal to 12 mm, resistant. Bacteria with minimal inhibitory concentrations (MICs) less than or equal to 16 micrograms/ml are considered susceptible; those with MICs greater than or equal to 32 micrograms/ml are considered resistant to norfloxacin. The mechanism of action of norfloxacin involves inhibition of the A subunit of the important bacterial enzyme DNA gyrase, which is essential for DNA replication. Plasmid-mediated resistance to the fluoroquinolones is not encountered. Further, although some cross-resistance within the fluoroquinolone class has occurred, there is little cross-resistance between norfloxacin and antibiotics of other classes.

Bacteria, Anaerobic↗

PubMed1996

Relationships between clinical parameters, Interleukin 1B and histopathologic findings of gingival tissue in periodontitis patients.

IL-1 beta is one of the cytokines which can induce bone resorption and connective tissue destruction. Previous studies demonstrated that the amount of IL-1 beta in gingival crevicular fluid (GCF) was closely related to the severity of gingival index (GI) and probing depth (PD). To further investigate whether the amount of IL-1 beta in GCF and the tissues adjacent to the periodontal pockets can reflect the degree of inflammation and destruction of these tissues, the GCF and inflamed gingival specimens were harvested from 14 periodontal patients and IL-1 beta in these samples was measured by ELISA. Clinical parameters of the sampled teeth were also recorded. Possible relations among periodontal parameters, GCF or tissue IL-1 beta and the degrees of inflammation in tissue sections were analysed statistically. The results showed that with increasing GI and PD, there was an elevation of GCF and tissue IL-1 beta activity. GCF flow also showed a tendency to increase with a higher percentage of inflammatory infiltrate. The GCF and tissue IL-1 beta activity were significantly correlated with clinical parameters (GI, PD and GCF flow), as well as with the percentage of inflammatory infiltrate and tissue alterations. With the exception of a significantly negative correlation with the extent of inflammation, no obvious relation between the GCF or tissue concentration of IL-1 beta and the state of tissue pathology could be detected. In conclusion, measurements of IL-1 beta activity in GCF or diseased tissues based on the classification of clinical parameters can reflect the degree of inflammation within periodontal disease tissue. These observations indicate that clinical parameters can provide reliable means of evaluation of the severity of periodontal disease, and that IL-1 beta plays a pivotal role in the pathogenic mechanism of periodontal tissue destruction.

Adult↗

PubMed2003

Polymerase chain reaction-based genotype classification among human Blastocystis hominis populations isolated from different countries.

Since the genotype of human Blastocystis hominis isolates is highly polymorphic, PCR-based genotype classification using known sequenced-tagged site (STS) primers would allow the identification or classification of different genotypes. Five populations of human B. hominis isolates obtained from Japan, Pakistan, Bangladesh, Germany, and Thailand were subjected to genotype analysis by using seven kinds of STS primers. Ninety-nine out of 102 isolates were identified as one of the known genotypes, while one isolate from Thailand showed two distinct genotypes and two isolates from Japan were negative with all the STS primers. The most dominant genotype among four populations, except for all four isolates from Thailand, was subtype 3 and it varied from 41.7% to 92.3%. The second most common genotype among four populations was either subtype 1 (7.7-25.0%) or subtype 4 (10.0-22.9%). Subtype 2, subtype 5, and/or subtype 7 were only rarely detected among the isolates from Japan and Germany, while subtype 6 was not detected. The phylogenetic position of the two isolates which were negative with all STS primers, was inferred from the small subunit rRNA (SSU rRNA) genes with the known sequence data of 20 Blastocystis isolates. Since the two isolates were positioned in an additional clade in the phylogenetic tree, this suggested they were a new genotype. These results demonstrated that PCR-based genotype classification is a powerful tool with which to analyse genotypes of Blastocystis isolates obtained from clinical samples. In addition, two groups of the isolates from 15 symptomatic and 11 asymptomatic patients in Bangladesh were compared with the PCR-based subtype classification. Since both groups were only classified into two distinct genotypes of subtype 1 or subtype 3 and no statistically significant difference was observed between the two groups, in this study it could not be shown that the specific genotype correlated with the pathogenic potential of B. hominis.

Animals↗

PubMedDate not supplied

[Takayasu-type arteriopathies. Apropos of 4 cases observed in Ivory Coast].

Report of 4 cases of Takayasu type arteriopathy observed in the internal medicine department of Treichville Hospital (Abidjan University). During a one year study the prevalence appeared high in African women: 0.4 p. 100 of all female admittances; 1.2 of the female patients under 35 years; 2 p. 100 of the females admitted for cardiovascular disease. Diagnosis criteria are studied: epidemiological criteria (young age, with a mean value of 21 years); clinical and biological criteria: high blood pressure associated with the absence of one or several arterial peripheric pulses and the presence of one or several arterial murmurs; biological criteria which are negative in the four cases this negativity indicating an occlusive phase. Aortography is the main diagnosis support, showing the situation of the lesions, permitting a topographic classification and giving the mechanisms of blood hypertension with, sometimes, a therapeutic consequence. In one case an inflammatory condition of the aorta has been observed at the media adventitia junction. A systematic study of etiology has brought no evidence of another possible diagnosis. Pathogenic role of tuberculosis is suspected but had not yet been demonstrated.

Adolescent↗

PubMed1995

Pneumonia and influenza death rates--United States, 1979-1994.

The combined cause-of-death category pneumonia and influenza (P&I) (International Classification of Diseases, Ninth Revision, codes 480-487) ranks as the sixth leading cause of death in the United States following heart disease, cancer, stroke, unintentional injuries, and chronic obstructive pulmonary disease. Changes in the epidemiology of Streptococcus pneumoniae and other recognized respiratory pathogens, the increasing occurrence of drug-resistant microorganisms, and the detection of new respiratory pathogens have heightened awareness of the public health importance of severe respiratory infections. To characterize the epidemiology of P&I deaths in the United States, CDC further analyzed underlying and multiple cause-of-death mortality files for 1979-1994. This report summarizes the results of this analysis.

Adult↗

PubMed2004

Comparative proteomics of the Mycobacterium leprae binding protein myelin P0: its implication in leprosy and other neurodegenerative diseases.

Mycobacterium leprae, the causative agent of leprosy invades Schwann cells of the peripheral nerves leading to nerve damage and disfigurement, which is the hallmark of the disease. Wet experiments have shown that M. leprae binds to a major peripheral nerve protein, the myelin P zero (P0). This protein is specific to peripheral nerve and may be important in the initial step of M. leprae binding and invasion of Schwann cells which is the feature of leprosy. Though the receptors on Schawann cells, cytokines, chemokines and antibodies to M. leprae have been identified the molecular mechanism of nerve damage and neurodegeneration is not clearly defined. Recently pathogen and host protein/nucleotide sequence similarities (molecular mimicry) have been implicated in neurodegenerative diseases. The approach of the present study is to utilise bioinformatic tools to understand leprosy nerve damage by carrying out sequence and structural similarity searches of myelin P0 with leproma and other genomic database. Since myelin P0 is unique to peripheral nerve, its sequence and structural similarities in other neuropathogens have also been noted. Comparison of myelin P0 with the M. leprae proteins revealed two characterised proteins, Ferrodoxin NADP reductase and a conserved membrane protein, which showed similarity to the query sequence. Comparison with the entire genomic database (www.ncbi.nlm.nih.gov) by basic local alignment search tool for proteins (BLASTP) and fold classification of structure-structure alignment of proteins (FSSP) searches revealed that myelin P0 had sequence/structural similarities to the poliovirus receptor, coxsackie-adenovirus receptor, anthrax protective antigen, diphtheria toxin, herpes simplex virus, HIV gag-1 peptide, and gp120 among others. These proteins are known to be associated directly or indirectly with neruodegeneration. Sequence and structural similarities to the immunoglobin regions of myelin P0 could have implications in host-pathogen interactions, as it has homophilic adhesive properties. Although these observed similarities are not highly significant in their percentage identity, they could be functionally important in molecular mimicry, receptor binding and cell signaling events involved in neurodegeneration.

Amino Acid Sequence↗

PubMed2006

Characterization and serological classification of O-specific polysaccharide of Proteus mirabilisTG 276-90 from Proteus serogroup O34.

INTRODUCTION: Gram-negative bacteria of the genus Proteus from the family Enterobacteriaceae are currently divided into the five species P. mirabilis, P. vulgaris, P. penneri, P. hauseri, and P. myxofaciens and three unnamed Proteus genomospecies 4, 5, and 6. They are important facultative human and animal pathogens which, under favorable conditions, cause mainly intestinal and urinary tract infections, sometimes leading to serious complications such as acute or chronic pyelonephritis and the formation of bladder and kidney stones. In this study we report on the serological properties of the lipopolysaccharide (LPS) of P. mirabilis TG 276-90, whose O-polysaccharide chemical structure was described earlier. MATERIALS AND METHODS: LPS and alkali-treated LPS of a few serologically related Proteus strains and O-antisera against P. mirabilis TG 276-90 and CCUG 4669 (O34) were used. Serological characterization of P. mirabilis TG 276-90 O-specific polysaccharide was done using enzyme immunosorbent assay, passive immunohemolysis test (PIH), inhibition of these tests, SDS/PAGE and Western blot techniques, absorption of rabbit polyclonal O-antisera, and repeated PIH test. RESULTS: Structural and serological investigations showed that the O-polysaccharides of P. mirabilis TG 276-90 and P. vulgaris O34 are identical and that their LPSs differ only in epitopes in the core part. Therefore these two strains could be classified into the same Proteus O34 serogroup. CONCLUSIONS: The serological data showed that the beta-D-GalpNAc-(1--> 4)-alpha-D-GalpNAc disaccharide is an important epitope of the P. mirabilis TG 276-90 and P. vulgaris O34 LPSs, shared by the P. mirabilis O16 and P. vulgaris TG 251 LPSs. It is responsible for cross-reactions with P. mirabilis TG 276-90 and P. vulgaris O34 O-antisera.

Carbohydrate Sequence↗

PubMed2001

Typing of Scedosporium apiospermum by multilocus enzyme electrophoresis and random amplification of polymorphic DNA.

The genetic diversity among epidemiologically unrelated strains of the human pathogenic fungus Scedosporium apiospermum or its teleomorph, Pseudallescheria boydii, from different areas in Europe, was investigated by multilocus enzyme electrophoresis (MLEE) and random amplification of polymorphic DNA (RAPD). Fourteen enzyme activities were analysed by starch gel electrophoresis, corresponding to 27 polymorphic loci and 43 iso-enzymes. Among the enzymes studied, propionate esterase, carboxyl esterase, superoxide dismutase, carbonate dehydratase and malate dehydrogenase were the most polymorphic, allowing the classification of the strains into 6-11 groups each. Combination of the data obtained for the different enzyme activities studied allowed differentiation of the strains. Similarly, a high polymorphism was also revealed by each of the 20 RAPD primers tested, but no single primer was able to differentiate all the strains. The most efficient primers were GC70, UBC-701 and UBC-703, which revealed 17 distinct genotypes each, and combination of the results obtained with this three-primer set allowed complete discrimination of the strains. The dendrograms obtained from MLEE or RAPD by the unweighted pair-group method using arithmetic average cluster analysis did not reveal any clustering according to the geographic origin of the strains or their pathogenicity.

Cluster Analysis↗

PubMed2026

XXYLT1 and Mendelian Retinal Dystrophy.

IMPORTANCE: Substantial unexplained heritability remains for pathogenic inherited retinal disease (IRD) variants. Application of genome-wide association studies (GWAS) could help identify causal genes in rare diseases. OBJECTIVE: To leverage a GWAS for the discovery of IRD-associated genes. DESIGN, SETTING, AND PARTICIPANTS: This GWAS analysis was combined with replication of findings in 2 independent IRD cohorts. The study was conducted from January 2024 to December 2025 in a multicenter setting through FinnGen, 100 000 Genomes Project, and the National Health Service Genomic Medicine Service combined with clinical cohort from the Oulu University Hospital. Using IRD criteria from the International Classification of Diseases, 9th and 10th Revisions, 540 individuals with IRD and 473 945 control individuals were identified in the FinnGen study. For validation of FinnGen results, 49 patients were recruited from Oulu University Hospital. Results were further validated in 2 individuals identified from the UK cohort. MAIN OUTCOMES AND MEASURES: The GWAS and proteomics analysis were performed in the FinnGen cohort. Sanger and whole-genome sequencing and RNA approaches were used in a clinical IRD cohort to validate pathogenicity of the identified XXYLT1 variant. RESULTS: This GWAS identified 13 recessive loci reaching genome-wide significance (defined as P < 5 × 10-8). Of these, 4 (near or within XXYLT1, ANKRD10, DYM, and CBLN4) had not been associated with IRD, including the XXYLT1 c.505-1G>C founder variant. This variant was further genotyped in the clinical replication cohort, leading to identification of 5 more homozygous individuals from 4 families. The phenotype was consistent with a cone-rod or macular dystrophy, with visual deterioration, cystoid macular edema and/or schisislike macular abnormalities. The effect of the XXYLT1 c.505-1G>C variant was further investigated using RNA sequencing and complementary DNA amplicon sequencing, demonstrating exon 2 skipping and a loss-of-function effect. These findings were replicated in an independent population identifying 2 patients from the UK harboring a homozygous XXYLT1 c.766G>A, p.(Glu256Lys) missense variant. CONCLUSIONS AND RELEVANCE: This GWAS identified an association between XXYLT1 and IRD. These results affirm that GWAS in a founder population can be used as a potential tool for the discovery of rare mendelian disease genes and that XXYLT1 should be considered in clinical IRD gene panels.

Humans↗

PubMed1999

[Nasal polyps. Definitions and development of pathogenesis theory].

This paper presents definitions and types of classifications of nasal polyps. The precise pathogenesis of nasal polyps is not known, although there are several important factors: chronic and recurrent infection of nasal mucose, abnormal vasomotor response, airflow blockade of the middle meatus and ostia of the paranasal sinuses. Since 1843 several pathogenic theories have been introduced.

Humans↗

PubMed2006

Surveillance for waterborne disease and outbreaks associated with drinking water and water not intended for drinking--United States, 2003-2004.

PROBLEM/CONDITION: Since 1971, CDC, the U.S. Environmental Protection Agency (EPA), and the Council of State and Territorial Epidemiologists have maintained a collaborative Waterborne Disease and Outbreaks Surveillance System for collecting and reporting data related to occurrences and causes of waterborne disease and outbreaks (WBDOs). This surveillance system is the primary source of data concerning the scope and effects of WBDOs in the United States. REPORTING PERIOD: Data presented summarize 36 WBDOs that occurred during January 2003-December 2004 and nine previously unreported WBDOs that occurred during 1982-2002. DESCRIPTION OF SYSTEM: The surveillance system includes data on WBDOs associated with drinking water, water not intended for drinking (excluding recreational water), and water of unknown intent. Public health departments in the states, territories, localities, and Freely Associated States (i.e., the Republic of the Marshall Islands, the Federated States of Micronesia, and the Republic of Palau, formerly parts of the U.S.-administered Trust Territory of the Pacific Islands) are primarily responsible for detecting and investigating WBDOs and voluntarily reporting them to CDC by using a standard form. RESULTS: During 2003-2004, a total of 36 WBDOs were reported by 19 states; 30 were associated with drinking water, three were associated with water not intended for drinking, and three were associated with water of unknown intent. The 30 drinking water-associated WBDOs caused illness among an estimated 2,760 persons and were linked to four deaths. Etiologic agents were identified in 25 (83.3%) of these WBDOs: 17 (68.0%) involved pathogens (i.e., 13 bacterial, one parasitic, one viral, one mixed bacterial/parasitic, and one mixed bacterial/parasitic/viral), and eight (32.0%) involved chemical/toxin poisonings. Gastroenteritis represented 67.7% of the illness related to drinking water-associated WBDOs; acute respiratory illness represented 25.8%, and dermatitis represented 6.5%. The classification of deficiencies contributing to WBDOs has been revised to reflect the categories of concerns associated with contamination at or in the source water, treatment facility, or distribution system (SWTD) that are under the jurisdiction of water utilities, versus those at points not under the jurisdiction of a water utility or at the point of water use (NWU/POU), which includes commercially bottled water. A total of 33 deficiencies were cited in the 30 WBDOs associated with drinking water: 17 (51.5%) NWU/POU, 14 (42.4%) SWTD, and two (6.1%) unknown. The most frequently cited NWU/POU deficiencies involved Legionella spp. in the drinking water system (n = eight [47.1%]). The most frequently cited SWTD deficiencies were associated with distribution system contamination (n = six [42.9%]). Contaminated ground water was a contributing factor in seven times as many WBDOs (n = seven) as contaminated surface water (n = one). INTERPRETATION: Approximately half (51.5%) of the drinking water deficiencies occurred outside the jurisdiction of a water utility in situations not currently regulated by EPA. The majority of the WBDOs in which deficiencies were not regulated by EPA were associated with Legionella spp. or chemicals/toxins. Problems in the distribution system were the most commonly identified deficiencies under the jurisdiction of a water utility, underscoring the importance of preventing contamination after water treatment. The substantial proportion of WBDOs involving contaminated ground water provides support for the Ground Water Rule (finalized in October 2006), which specifies when corrective action is required for public ground water systems. PUBLIC HEALTH ACTIONS: CDC and EPA use surveillance data to identify the types of water systems, deficiencies, and etiologic agents associated with WBDOs and to evaluate the adequacy of current technologies and practices for providing safe drinking water. Surveillance data also are used to establish research priorities, which can lead to improved water-quality regulation development. The growing proportion of drinking water deficiencies that are not addressed by current EPA rules emphasizes the need to address risk factors for water contamination in the distribution system and at points not under the jurisdiction of water utilities.

Communicable Diseases↗