Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

Volume 11, Number 10—October 2005

Volume 11, Number 10—October 2005   PDF Version [PDF - 6.12 MB - 159 pages]


  • Antimicrobial Drug Resistance: "Prediction Is Very Difficult, Especially about the Future" PDF Version [PDF - 93 KB - 4 pages]
    P. Courvalin
    View Summary

    Although resistance cannot be prevented, much can be done to delay it.

        View Abstract

    Evolution of bacteria towards resistance to antimicrobial drugs, including multidrug resistance, is unavoidable because it represents a particular aspect of the general evolution of bacteria that is unstoppable. Therefore, the only means of dealing with this situation is to delay the emergence and subsequent dissemination of resistant bacteria or resistance genes. Resistance to antimicrobial drugs in bacteria can result from mutations in housekeeping structural or regulatory genes. Alternatively, resistance can result from the horizontal acquisition of foreign genetic information. The 2 phenomena are not mutually exclusive and can be associated in the emergence and more efficient spread of resistance. This review discusses the predictable future of the relationship between antimicrobial drugs and bacteria.

  • Emerging Foodborne Trematodiasis PDF Version [PDF - 231 KB - 8 pages]
    J. Keiser and J. Utzinger
    View Summary

    Foodborne trematodiasis is emerging because of increased aquaculture.

        View Abstract

    Foodborne trematodiasis is an emerging public health problem, particularly in Southeast Asia and the Western Pacific region. We summarize the complex life cycle of foodborne trematodes and discuss its contextual determinants. Currently, 601.0, 293.8, 91.1, and 79.8 million people are at risk for infection with Clonorchis sinensis, Paragonimus spp., Fasciola spp., and Opisthorchis spp., respectively. The relationship between diseases caused by trematodes and proximity of human habitation to suitable freshwater bodies is examined. Residents living near freshwater bodies have a 2.15-fold higher risk (95% confidence interval 1.38–3.36) for infections than persons living farther from the water. Exponential growth of aquaculture may be the most important risk factor for the emergence of foodborne trematodiasis. This is supported by reviewing aquaculture development in countries endemic for foodborne trematodiasis over the past 10–50 years. Future and sustainable control of foodborne trematodiasis is discussed.


  • Evolution of H5N1 Avian Influenza Viruses in Asia PDF Version [PDF - 307 KB - 7 pages]
    View Summary

    Human infections were from a virus clade undergoing antigenic drift that showed resistance to adamantanes but sensitivity to neuraminidase inhibitors.

        View Abstract

    An outbreak of highly pathogenic avian influenza A (H5N1) has recently spread to poultry in 9 Asian countries. H5N1 infections have caused >52 human deaths in Vietnam, Thailand, and Cambodia from January 2004 to April 2005. Genomic analyses of H5N1 isolates from birds and humans showed 2 distinct clades with a nonoverlapping geographic distribution. All the viral genes were of avian influenza origin, which indicates absence of reassortment with human influenza viruses. All human H5N1 isolates tested belonged to a single clade and were resistant to the adamantane drugs but sensitive to neuraminidase inhibitors. Most H5N1 isolates from humans were antigenically homogeneous and distinct from avian viruses circulating before the end of 2003. Some 2005 isolates showed evidence of antigenic drift. An updated nonpathogenic H5N1 reference virus, lacking the polybasic cleavage site in the hemagglutinin gene, was produced by reverse genetics in anticipation of the possible need to vaccinate humans.

  • New Measles Genotype, Uganda PDF Version [PDF - 203 KB - 5 pages]
    A. Muwonge et al.
    View Summary

    New measles virus genotype will increase epidemiologic and virologic surveillance in Africa.

        View Abstract

    We report the first genetic characterization of wildtype measles viruses from Uganda. Thirty-six virus isolates from outbreaks in 6 districts were analyzed from 2000 to 2002. Analyses of sequences of the nucleoprotein (N) and hemagglutinin (H) genes showed that the Ugandan isolates were all closely related, and phylogenetic analysis indicated that these viruses were members of a unique group within clade D. Sequences of the Ugandan viruses were not closely related to any of the World Health Organization reference sequences representing the 22 currently recognized genotypes. The minimum nucleotide divergence between the Ugandan viruses and the most closely related reference strain, genotype D2, was 3.1% for the N gene and 2.6% for the H gene. Therefore, Ugandan viruses should be considered a new, proposed genotype (d10). This new sequence information will expand the utility of molecular epidemiologic techniques for describing measles transmission patterns in eastern Africa.

  • Pyrosequencing Bacillus anthracis PDF Version [PDF - 251 KB - 5 pages]
    T. Wahab et al.
    View Summary

    Pyrosequencing technology was used to rapidly and specifically identify Bacillus anthracis.

        View Abstract

    Pyrosequencing technology is a sequencing method that screens DNA nucleotide incorporation in real time. A set of coupled enzymatic reactions, together with bioluminescence, detects incorporated nucleotides in the form of light pulses, which produces a profile of characteristic peaks in a pyrogram. We used this technology to identify the warfare agent Bacillus anthracis by sequencing 4 single nucleotide polymorphisms (SNPs) in the rpoB gene as chromosomal markers for B. anthracis. In addition, 1 segment in each of the B. anthracis plasmids pXO1 and pXO2 was analyzed to determine the virulence status of the bacterial strains. Pyrosequencing technology is a powerful method to identify B. anthracis.

  • Community-associated Methicillin-resistant Staphylococcus aureus, Minnesota, 2000–2003 PDF Version [PDF - 131 KB - 7 pages]
    J. M. Buck et al.
    View Summary

    Community-associated methicillin-resistant Staphylococcus aureus (MRSA) invasive disease resembled healthcare-associated MRSA disease.

        View Abstract

    We compared characteristics of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) skin and soft tissue infections (SSTIs) and CA-MRSA invasive disease identified in Minnesota from 2000 through 2003. A total of 586 patients with SSTIs and 65 patients with invasive disease were identified. Patients with invasive disease were more likely to be smokers (p = 0.03), and report a history of immunosuppressive therapy (p = 0.03), emphysema (p = 0.011), or injection drug use (p = 0.020) than were SSTI patients. Invasive disease isolates were less likely to be susceptible to ciprofloxacin (p = 0.002) and clindamycin (p = 0.001) and more likely to have healthcare-associated pulsed-field gel electrophoresis subtypes than SSTI isolates (p<0.001). Patients with invasive disease may have had healthcare exposures that put them at risk of acquiring healthcare-associated MRSA and which were not exclusion criteria in the CA-MRSA case definition. Continued surveillance of MRSA is needed to better characterize CA-MRSA infections.

  • Methicillin-resistant Staphylococcus aureus and Vancomycin-resistant Enterococci Co-colonization PDF Version [PDF - 163 KB - 6 pages]
    J. P. Furuno et al.
    View Summary

    High prevalence of co-colonization increases risk for colonization or infection by vancomycin-resistant Staphylococcus aureus.

        View Abstract

    We assessed the prevalence, risk factors, and clinical outcomes of patients co-colonized with vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) upon admission to the medical and surgical intensive care units (ICUs) of a tertiary-care facility between January 1, 2002, and December 31, 2003. Co-colonization was defined as a VRE-positive perirectal surveillance culture with an MRSA-positive anterior nares surveillance culture collected concurrently. Among 2,440 patients, 65 (2.7%) were co-colonized. Independent risk factors included age (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01–1.05), admission to the medical ICU (OR 4.38, 95% CI 2.46–7.81), male sex (OR 1.93, 95% CI 1.14–3.30), and receiving antimicrobial drugs on a previous admission within 1 year (OR 3.06, 95% CI 1.85–5.07). None of the co-colonized patients would have been identified with clinical cultures alone. We report a high prevalence of VRE/MRSA co-colonization upon admission to ICUs at a tertiary-care hospital.

  • Mallards and Highly Pathogenic Avian Influenza Ancestral Viruses, Northern Europe PDF Version [PDF - 264 KB - 7 pages]
    V. J. Munster et al.
    View Summary

    Surveillance studies in wild birds help generate prototypic vaccine candidates and diagnostic tests.

        View Abstract

    Outbreaks of highly pathogenic avian influenza (HPAI), which originate in poultry upon transmission of low pathogenic viruses from wild birds, have occurred relatively frequently in the last decade. During our ongoing surveillance studies in wild birds, we isolated several influenza A viruses of hemagglutinin subtype H5 and H7 that contain various neuraminidase subtypes. For each of the recorded H5 and H7 HPAI outbreaks in Europe since 1997, our collection contained closely related virus isolates recovered from wild birds, as determined by sequencing and phylogenetic analyses of the hemagglutinin gene and antigenic characterization of the hemagglutinin glycoprotein. The minor genetic and antigenic diversity between the viruses recovered from wild birds and those causing HPAI outbreaks indicates that influenza A virus surveillance studies in wild birds can help generate prototypic vaccine candidates and design and evaluate diagnostic tests, before outbreaks occur in animals and humans.

  • Isolate Removal Methods and Methicillin-resistant Staphylococcus aureus Surveillance PDF Version [PDF - 205 KB - 6 pages]
    F. Li et al.
    View Summary

    The first Staphylococcus aureus isolate from a patient should be used to calculate oxacillin susceptibility frequency.

        View Abstract

    The effect of duplicate isolate removal strategies on Staphylococcal aureus susceptibility to oxacillin was compared by using antimicrobial test results for 14,595 isolates from statewide surveillance in Hawaii in 2002. No removal was compared to most resistant and most susceptible methods at 365 days and to the National Committee for Clinical Laboratory Standards (NCCLS) and Cerner algorithms at 3-, 10-, 30-, 90-, and 365-day analysis periods. Overall, no removal produced the lowest estimates of susceptibility. Estimates with either NCCLS or Cerner differed by <2% when the analysis period was the same; with either method, the difference observed between a 90- and a 365-day period was <1%. The effect of duplicate isolate removal was greater for inpatient than outpatient settings. Considering the ease of implementation and comparability of results, we recommend using the first isolate of a given species per patient to calculate susceptibility frequencies for S. aureus to oxacillin.

  • Vancomycin and Home Health Care PDF Version [PDF - 152 KB - 7 pages]
    T. G. Fraser et al.
    View Summary

    Microbiologic diagnosis before hospital discharge and physician education may limit inappropriate vancomycin use in homecare patients.

        View Abstract

    The Hospital Infection Control Practices Advisory Committee published guidelines for prudent use of vancomycin to combat increasing resistance to antimicrobial drugs. Studies examining compliance with these guidelines primarily involve hospitalized patients. The growing practice of home use of antimicrobial drugs led to this retrospective cohort study that evaluated parenteral vancomycin use in patients receiving it through a homecare agency. We found that 39.2% of outpatients received vancomycin outside the guidelines, mainly because of prolonged empiric therapy, dosing convenience, and prolonged use after surgery. Patients were more likely to receive vancomycin appropriately if they were >65 years of age, had a history of malignancy, or were discharged from a medical service. In addition, obtaining wound cultures and attempting a microbiologic diagnosis led to more appropriate vancomycin use. Recommendations for prudent vancomycin use are often overlooked when selecting antimicrobial drugs for home infusion. The public health impact of this practice remains unknown.

  • Antibacterial Cleaning Products and Drug Resistance PDF Version [PDF - 151 KB - 6 pages]
    A. E. Aiello et al.
    View Summary

    Levels of antimicrobial drug resistance did not differ significantly between persons in households that used antibacterial cleaning and hygiene products and those that did not.

        View Abstract

    We examined whether household use of antibacterial cleaning and hygiene products is an emerging risk factor for carriage of antimicrobial drug–resistant bacteria on hands of household members. Households (N = 224) were randomized to use of antibacterial or nonantibacterial cleaning and hygiene products for 1 year. Logistic regression was used to assess the influence of antibacterial product use in homes. Antibacterial product use did not lead to a significant increase in antimicrobial drug resistance after 1 year (odds ratio 1.33, 95% confidence interval 0.74–2.41), nor did it have an effect on bacterial susceptibility to triclosan. However, more extensive and longer term use of triclosan might provide a suitable environment for emergence of resistant species. Further research on this issue is needed.

  • Plasmodium falciparum Spatial Analysis, Western Kenya Highlands PDF Version [PDF - 218 KB - 7 pages]
    O. G. Munyekenye et al.
    View Summary

    Parasite transmission is intense in the highlands, and these areas are vulnerable to epidemics.

        View Abstract

    We carried out a population-based study to determine the unbiased, age-specific Plasmodium falciparum prevalence, asexual and sexual parasite density, and spatial distribution to establish rates of infection at a site in western Kenya. Three cross-sectional surveys were carried out in western Kenya highlands. Blood samples were taken from 1,388 persons from 6 months to 75 years of age. Parasite prevalence and densities in the population decreased with age and distance from valley bottoms. Children from 1 to 4 years of age had the highest parasite prevalence (38.8%–62.8%); in adults, prevalence declined to 2.9%–24.1%. Malaria prevalence declined by an average of 19% from July to December 2002 across age groups. These observations suggest that parasite transmission is intense at this altitude. Asexual parasite density indicated clustering near major vector breeding habitats. Variability in seasonal prevalence indicates transmission instability and susceptibility to epidemics.

  • Botulinum Neurotoxin Detection and Differentiation by Mass Spectrometry PDF Version [PDF - 264 KB - 6 pages]
    J. R. Barr et al.
    View Summary

    A new rapid, mass spectrometry-based method to detect and differentiate botulinal neurotoxins is described.

        View Abstract

    Botulinum neurotoxins (BoNTs) are proteases that cleave specific cellular proteins essential for neurotransmitter release. Seven BoNT serotypes (A–G) exist; 4 usually cause human botulism (A, B, E, and F). We developed a rapid, mass spectrometry–based method (Endopep-MS) to detect and differentiate active BoNTs A, B, E, and F. This method uses the highly specific protease activity of the toxins with target peptides specific for each toxin serotype. The product peptides derived from the endopeptidase activities of BoNTs are detected by matrix-assisted laser-desorption ionization time-of-flight mass spectrometry. In buffer, this method can detect toxin equivalents of as little as 0.01 mouse lethal dose (MLD)50 and concentrations as low as 0.62 MLD50/mL. A high-performance liquid chromatography–tandem mass spectrometry method for quantifying active toxin, where the amount of toxin can be correlated to the amount of product peptides, is also described.

  • Methicillin-resistant Staphylococcus aureus, Western Australia PDF Version [PDF - 226 KB - 7 pages]
    L. Dailey et al.
    View Summary

    Endemic MRSA persists in Western Australia despite control measures.

        View Abstract

    Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a notable cause of hospital-acquired infections. A statewide screening and control policy was implemented in Western Australia (WA) after an outbreak of epidemic MRSA in a Perth hospital in 1982. We report on statutory notifications from1998 to 2002 and review the 20-year period from 1983 to 2002. The rate of reporting of community-associated Western Australia MRSA (WAMRSA) escalated from 1998 to 2002 but may have peaked in 2001. Several outbreaks were halted, but they resulted in an increase in reports as a result of screening. A notable increase in ciprofloxacin resistance during the study period was observed as a result of more United Kingdom epidemic MRSA (EMRSA) -15 and -16. WA has seen a persistently low incidence of multidrug-resistant MRSA because of the screening and decolonization program. Non–multidrug-resistant, community-associated WAMRSA strains have not established in WA hospitals.


  • Atypical Infections in Tsunami Survivors PDF Version [PDF - 85 KB - 3 pages]
    C. Garzoni et al.
        View Abstract

    After a tsunami hit Asia in December 2004, 2 survivors had severe infections due to multidrug-resistant and atypical bacteria and rare fungi weeks afterwards. Treating these infections is challenging from a clinical and microbiologic point of view.

  • Genetic Characterization of Nipah Virus, Bangladesh, 2004 PDF Version [PDF - 142 KB - 4 pages]
    B. H. Harcourt et al.
        View Abstract

    Until 2004, identification of Nipah virus (NV)-like outbreaks in Bangladesh was based on serology. We describe the genetic characterization of a new strain of NV isolated during outbreaks in Bangladesh (NV-B) in 2004, which confirms that NV was the etiologic agent responsible for these outbreaks.

  • Diphyllobothriasis, Brazil PDF Version [PDF - 284 KB - 3 pages]
    J. Sampaio et al.
        View Abstract

    Cases of human diphyllobothriasis have been reported worldwide. Only 1 case in Brazil was diagnosed by our institution from January 1998 to December 2003. By comparison, 18 cases were diagnosed from March 2004 to January 2005. All patients who became infected ate raw fish in sushi or sashimi.

  • Poultry-handling Practices during Avian Influenza Outbreak, Thailand PDF Version [PDF - 77 KB - 3 pages]
    S. J. Olsen et al.
        View Abstract

    With poultry outbreaks of avian influenza H5N1 continuing in Thailand, preventing human infection remains a priority. We surveyed residents of rural Thailand regarding avian influenza knowledge, attitudes, and practices. Results suggest that public education campaigns have been effective in reaching those at greatest risk, although some high-risk behavior continues.

  • Anaplasma phagocytophilum in White-tailed Deer PDF Version [PDF - 94 KB - 3 pages]
    R. F. Massung et al.
        View Abstract

    We examined the reservoir potential of white-tailed deer for Anaplasma phagocytophilum. Results suggest that white-tailed deer harbor a variant strain not associated with human infection, but contrary to published reports, white-tailed deer are not a reservoir for strains that cause human disease. These results will affect surveillance studies of vector and reservoir populations.

  • Melioidosis in New Caledonia PDF Version [PDF - 134 KB - 3 pages]
    S. Le Hello et al.
        View Abstract

    Recognized melioidosis-endemic areas are widening. In the South Pacific, melioidosis is endemic in New Caledonia, northern Australia, and Papua New Guinea. We report the first 4 documented cases of human melioidosis from New Caledonia. Molecular typing of 2 Burkholderia pseudomallei isolates suggests a link to Australian strains.

  • Oropouche Virus Isolation, Southeast Brazil PDF Version [PDF - 213 KB - 4 pages]
    M. Nunes et al.
        View Abstract

    An Oropouche virus strain was isolated from a novel host (Callithrix sp.) in Arinos, Minas Gerais State, southeastern Brazil. The virus was identified by complement fixation test and confirmed by reverse transcription–polymerase chain reaction. Phylogenetic analysis identified this strain as a genotype III isolate previously recognized only in Panama.

  • Drug-resistant Escherichia coli, Rural Idaho PDF Version [PDF - 100 KB - 4 pages]
    E. L. Hannah et al.
        View Abstract

    Stool carriage of drug-resistant Escherichia coli in home-living residents of a rural community was examined. Carriage of nalidixic acid–resistant E. coli was associated with recent use of antimicrobial agents in the household. Household clustering of drug-resistant E. coli was observed. Most carriers of drug-resistant E. coli lacked conventional risk factors.

  • Canine Leishmaniasis, Italy PDF Version [PDF - 151 KB - 3 pages]
    E. Ferroglio et al.
        View Abstract

    We report the results of a survey to determine the prevalence of canine leishmaniasis and the presence of sand flies in northwestern Italy, where autochthonous foci of canine leishmaniasis have not been reported. Active foci of canine leishmaniasis were identified, which suggests that the disease is now also endemic in continental climate areas.

  • Myocarditis Outbreak among Adults, Illinois, 2003 PDF Version [PDF - 141 KB - 4 pages]
    G. D. Huhn et al.
        View Abstract

    An outbreak of myocarditis occurred among adults in Illinois in 2003. Diagnostic testing of myocardial tissues from 3 patients and comprehensive tests for enterovirus and adenovirus of other specimens from patients were inconclusive. Appropriate specimen collection from patients with idiopathic cardiomyopathy and further enhancement of diagnostic techniques are needed.

  • Gastroenteritis Outbreak in British Troops, Iraq PDF Version [PDF - 510 KB - 4 pages]
    M. S. Bailey et al.
        View Abstract

    Gastroenteritis affected many British military personnel during the war in Iraq. In the first month, 1,340 cases were seen; 73% of patients required hospital admission and 36% were hospital staff. In a survey of 500 hospital staff, 76% reported gastroenteritis, which was more likely in clinical workers. Investigations showed only caliciviruses.

  • Detecting Biological Warfare Agents PDF Version [PDF - 149 KB - 4 pages]
    L. Song et al.
        View Abstract

    We developed a fiber-optic, microsphere-based, high-density array composed of 18 species-specific probe microsensors to identify biological warfare agents. We simultaneously identified multiple biological warfare agents in environmental samples by looking at specific probe responses after hybridization and response patterns of the multiplexed array.

  • Rapid West Nile Virus Antigen Detection PDF Version [PDF - 53 KB - 3 pages]
    N. A. Panella et al.
        View Abstract

    We compared the VecTest WNV antigen assay with standard methods of West Nile virus (WNV) detection in swabs from American Crows (Corvus brachyrhynchos) and House Sparrows (Passer domesticus). The VecTest detected WNV more frequently than the plaque assay and was comparable to a TaqMan reverse transcription–polymerase chain reaction.


Another Dimension


Books and Media

About the Cover


Conference Summaries