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Volume 16, Number 3—March 2010

Volume 16, Number 3—March 2010   PDF Version [PDF - 5.47 MB - 219 pages]


  • Preparing a Community Hospital to Manage Work-related Exposures to Infectious Agents in BioSafety Level 3 and 4 Laboratories PDF Version [PDF - 178 KB - 6 pages]
    G. F. Risi et al.
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    Construction of new BioSafety Level (BSL) 3 and 4 laboratories has raised concerns regarding provision of care to exposed workers because of healthcare worker (HCW) unfamiliarity with precautions required. When the National Institutes of Health began construction of a new BSL-4 laboratory in Hamilton, Montana, USA, in 2005, they contracted with St. Patrick Hospital in Missoula, Montana, for care of those exposed. A care and isolation unit is described. We developed a training program for HCWs that emphasized the optimal use of barrier precautions and used pathogen-specific modules and simulations with mannequins and fluorescent liquids that represented infectious body fluids. The facility and training led to increased willingness among HCWs to care for patients with all types of communicable diseases. This model may be useful for other hospitals, whether they support a BSL-4 facility, are in the proximity of a BSL-3 facility, or are interested in upgrading their facilities to prepare for exotic and novel infectious diseases.

  • Bartonella spp. Transmission by Ticks Not Established PDF Version [PDF - 211 KB - 6 pages]
    S. R. Telford and G. P. Wormser
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    Bartonella spp. infect humans and many animal species. Mainly because PCR studies have demonstrated Bartonella DNA in ticks, some healthcare providers believe that these microorganisms are transmitted by ticks. B. henselae, in particular, is regarded as being present in and transmissible by the Ixodes scapularis tick. The presence of a microbial agent within a tick, however, does not imply that the tick might transmit it during the course of blood feeding and does not confer epidemiologic importance. After a critical review of the evidence for and against tick transmission, we conclude that transmission of any Bartonella spp. by ticks, to animals or humans, has not been established. We are unaware of any well-documented case of B. henselae transmission by I. scapularis ticks.

  • Potential for Tick-borne Bartonelloses PDF Version [PDF - 184 KB - 7 pages]
    E. Angelakis et al.
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    As worldwide vectors of human infectious diseases, ticks are considered to be second only to mosquitoes. Each tick species has preferred environmental conditions and biotopes that determine its geographic distribution, the pathogens it vectors, and the areas that pose risk for tick-borne diseases. Researchers have identified an increasing number of bacterial pathogens that are transmitted by ticks, including Anaplasma, Borrelia, Ehrlichia, and Rickettsia spp. Recent reports involving humans and canines suggest that ticks should be considered as potential vectors of Bartonella spp. To strengthen this suggestion, numerous molecular surveys to detect Bartonella DNA in ticks have been conducted. However, there is little evidence that Bartonella spp. can replicate within ticks and no definitive evidence of transmission by a tick to a vertebrate host.


  • Serologic Markers for Detecting Malaria in Areas of Low Endemicity, Somalia, 2008 PDF Version [PDF - 260 KB - 8 pages]
    T. Bousema et al.
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    Areas in which malaria is not highly endemic are suitable for malaria elimination, but assessing transmission is difficult because of lack of sensitivity of commonly used methods. We evaluated serologic markers for detecting variation in malaria exposure in Somalia. Plasmodium falciparum or P. vivax was not detected by microscopy in cross-sectional surveys of samples from persons during the dry (0/1,178) and wet (0/1,128) seasons. Antibody responses against P. falciparum or P. vivax were detected in 17.9% (179/1,001) and 19.3% (202/1,044) of persons tested. Reactivity against P. falciparum was significantly different between 3 villages (p<0.001); clusters of seroreactivity were present. Distance to the nearest seasonal river was negatively associated with P. falciparum (p = 0.028) and P. vivax seroreactivity (p = 0.016). Serologic markers are a promising tool for detecting spatial variation in malaria exposure and evaluating malaria control efforts in areas where transmission has decreased to levels below the detection limit of microscopy.

  • Infection of Kissing Bugs with Trypanosoma cruzi, Tucson, Arizona, USA PDF Version [PDF - 205 KB - 6 pages]
    C. E. Reisenman et al.
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    Triatomine insects (Hemiptera: Reduviidae), commonly known as kissing bugs, are a potential health problem in the southwestern United States as possible vectors of Trypanosoma cruzi, the causative agent of Chagas disease. Although this disease has been traditionally restricted to Latin America, a small number of vector-transmitted autochthonous US cases have been reported. Because triatomine bugs and infected mammalian reservoirs are plentiful in southern Arizona, we collected triatomines inside or around human houses in Tucson and analyzed the insects using molecular techniques to determine whether they were infected with T. cruzi. We found that 41.5% of collected bugs (n = 164) were infected with T. cruzi, and that 63% of the collection sites (n = 22) yielded >1 infected specimens. Although many factors may contribute to the lack of reported cases in Arizona, these results indicate that the risk for infection in this region may be higher than previously thought.

  • Surveillance for West Nile Virus in American White Pelicans, Montana, USA, 2006–2007 PDF Version [PDF - 147 KB - 6 pages]
    G. P. Johnson et al.
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    West Nile virus (WNV)–associated deaths of American white pelican (Pelecanus erythrorhynchos) chicks have been recognized at various nesting colonies in the United States since 2002. We evaluated American white pelican nesting colonies in Sheridan County, Montana, USA, for an association between WNV-positive pelican carcasses and human West Nile neuroinvasive disease. Persons in counties hosting affected colonies had a 5× higher risk for disease than those in counties with unaffected colonies. We also investigated WNV infection and blood meal source among mosquitoes and pelican tissue type for greatest WNV detection efficacy in carcasses. WNV-infected Culex tarsalis mosquitoes were detected and blood-engorged Cx. tarsalis contained pelican DNA. Viral loads and detection consistency among pelican tissues were greatest in feather pulp, brain, heart, and skin. Given the risks posed to wildlife and human health, coordinated efforts among wildlife and public health authorities to monitor these pelican colonies for WNV activity are potentially useful.

  • Murine Typhus in Austin, Texas, USA, 2008 PDF Version [PDF - 215 KB - 6 pages]
    J. Adjemian et al.
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    In August 2008, Texas authorities and the Centers for Disease Control and Prevention investigated reports of increased numbers of febrile rash illnesses in Austin to confirm the causative agent as Rickettsia typhi, to assess the outbreak magnitude and illness severity, and to identify potential animal reservoirs and peridomestic factors that may have contributed to disease emergence. Thirty-three human cases of confirmed murine typhus were identified. Illness onset was reported from March to October. No patients died, but 23 (70%) were hospitalized. The case-patients clustered geographically in central Austin; 12 (36%) resided in a single ZIP code area. Specimens from wildlife and domestic animals near case-patient homes were assessed; 18% of cats, 44% of dogs, and 71% of opossums had antibodies reactive to R. typhi. No evidence of R. typhi was detected in the whole blood, tissue, or arthropod specimens tested. These findings suggest that an R. typhi cycle involving opossums and domestic animals may be present in Austin.

  • Chikungunya Virus Infection during Pregnancy, Réunion, France, 2006 PDF Version [PDF - 180 KB - 8 pages]
    X. Fritel et al.
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    Mother-to-child transmission of chikungunya virus was reported during the 2005–2006 outbreak on Réunion Island, France. To determine the effects of this virus on pregnancy outcomes, we conducted a study of pregnant women in Réunion in 2006. The study population was composed of 1,400 pregnant women (628 uninfected, 658 infected during pregnancy, 27 infected before pregnancy, and 87 infected on unknown dates). We compared pregnancy outcomes for 655 (628 + 27) women not infected during pregnancy with 658 who were infected during pregnancy. Infection occurred during the first trimester for 15% of the infected women, the second for 59%, and the third for 26%. Only hospital admission during pregnancy differed between infected and uninfected women (40% vs. 29%). Other outcomes (cesarean deliveries, obstetric hemorrhaging, preterm births, stillbirths after 22 weeks, birthweight, congenital malformations, and newborn admissions) were similar. This virus had no observable effect on pregnancy outcomes.

  • Effects of Mumps Outbreak in Hospital, Chicago, Illinois, USA, 2006 PDF Version [PDF - 178 KB - 7 pages]
    A. L. Bonebrake et al.
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    In 2006, nearly 6,000 mumps cases were reported in the United States, 795 of which occurred in Illinois. In Chicago, 1 healthcare institution experienced ongoing transmission for 4 weeks. This study examines the outbreak epidemiology and quantifies the financial affect on this organization. This retrospective cohort study was conducted through case and exposure identification, interviews, medical record reviews, and immunologic testing of blood specimens. Nine mumps cases resulted in 339 exposures, 325 (98%) among employees. During initial investigation, 186 (57%) of the exposed employees had evidence of mumps immunity. Physicians made up the largest group of noncompliers (55%) with mumps immunity testing. The cost to the institution was $262,788 or $29,199 per mumps case. The outbreak resulted in substantial staffing and financial challenges for the institution that may have been minimized with readily accessible electronic employee vaccination records and adherence to infection control recommendations.

  • Blood Meal Analysis to Identify Reservoir Hosts for Amblyomma americanum Ticks PDF Version [PDF - 173 KB - 8 pages]
    B. F. Allan et al.
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    Efforts to identify wildlife reservoirs for tick-borne pathogens are frequently limited by poor understanding of tick–host interactions and potentially transient infectivity of hosts under natural conditions. To identify reservoir hosts for lone star tick (Amblyomma americanum)–associated pathogens, we used a novel technology. In field-collected ticks, we used PCR to amplify a portion of the 18S rRNA gene in remnant blood meal DNA. Reverse line blot hybridization with host-specific probes was then used to subsequently detect and identify amplified DNA. Although several other taxa of wildlife hosts contribute to tick infection rates, our results confirm that the white-tailed deer (Odocoileus virginianus) is a reservoir host for several A. americanum–associated pathogens. Identification of host blood meal frequency and reservoir competence can help in determining human infection rates caused by these pathogens.

  • Borrelia, Ehrlichia, and Rickettsia spp. in Ticks Removed from Persons, Texas, USA PDF Version [PDF - 129 KB - 6 pages]
    P. C. Williamson et al.
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    Data regarding the type, frequency, and distribution of tick-borne pathogens and bacterial agents are not widely available for many tick species that parasitize persons in the southern United States. We therefore analyzed the frequency and identity of pathogens and bacterial agents in ticks removed from humans and subsequently submitted to the Texas Department of State Health Services, Zoonosis Control Program, from October 1, 2004, through September 30, 2008. The data showed associations of bacterial agents and potential vectors. Tick-related illnesses may pose unidentified health risks in areas such as Texas, where incidence of human disease related to tick bites is low but well above zero and where ticks are not routinely suspected as the cause of disease. Cause, treatment, and prevention strategies can be better addressed through collecting sufficient data to establish baseline assessments of risk.

  • New Endemic Legionella pneumophila Serogroup I Clones, Ontario, Canada PDF Version [PDF - 266 KB - 8 pages]
    N. Tijet et al.
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    The water-borne pathogen Legionella pneumophila serogroup 1 (Lp1) is the most commonly reported etiologic agent of legionellosis. To examine the genetic diversity, the long-term epidemiology, and the molecular evolution of Lp1 clinical isolates, we conducted sequence-based typing on a collection of clinical isolates representing 3 decades of culture-confirmed legionellosis in Ontario, Canada. Analysis showed that the population of Lp1 in Ontario is highly diverse and combines lineages identified worldwide with local strains. Identical types were identified in sporadic and outbreak-associated strains. In the past 15 years, the incidence of some lineages distributed worldwide has tended to decrease, and local endemic clones and lineages have emerged. Comparative geographic distribution analysis suggests that some lineages are specific to eastern North America. These findings have general clinical implications for the study of Lp1 molecular evolution and for the identification of Lp1 circulating strains in North America.

  • Invasive Haemophilus influenzae Disease, Europe, 1996–2006 PDF Version [PDF - 162 KB - 9 pages]
    S. N. Ladhani et al.
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    An international collaboration was established in 1996 to monitor the impact of routine Haemophilus influenzae type b (Hib) vaccination on invasive H. influenzae disease; 14 countries routinely serotype all clinical isolates. Of the 10,081 invasive H. influenzae infections reported during 1996–2006, 4,466 (44%, incidence 0.28 infections/100,000 population) were due to noncapsulated H. influenzae (ncHi); 2,836 (28%, 0.15/100,000), to Hib; and 690 (7%, 0.036/100,000), to non–b encapsulated H. influenzae. Invasive ncHi infections occurred in older persons more often than Hib (median age 58 years vs. 5 years, p<0.0001) and were associated with higher case-fatality ratios (12% vs. 4%, p<0.0001), particularly in infants (17% vs. 3%, p<0.0001). Among non-b encapsulated H. influenzae, types f (72%) and e (21%) were responsible for almost all cases; the overall case-fatality rate was 9%. Thus, the incidence of invasive non–type b H. influenzae is now higher than that of Hib and is associated with higher case fatality.

  • Vaccine Preventability of Meningococcal Clone, Greater Aachen Region, Germany PDF Version [PDF - 614 KB - 9 pages]
    J. Elias et al.
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    Emergence of serogroup B meningococci of clonal complex sequence type (ST) 41/44 can cause high levels of disease, as exemplified by a recent epidemic in New Zealand. Multiplication of annual incidence rates (3.1 cases/100,000 population) of meningococcal disease in a defined German region, the city of Aachen and 3 neighboring countries (Greater Aachen) prompted us to investigate and determine the source and nature of this outbreak. Using molecular typing and geographic mapping, we analyzed 1,143 strains belonging to ST41/44 complex, isolated from persons with invasive meningococcal disease over 6 years (2001–2006) from 2 German federal states (total population 26 million) and the Netherlands. A spatially slowly moving clone with multiple-locus variable-number tandem repeat analysis type 19, ST42, and antigenic profile B:P1.7–2,4:F1–5 was responsible for the outbreak. Bactericidal activity in serum samples from the New Zealand MeNZB vaccination campaign confirmed vaccine preventability. Because this globally distributed epidemic strain spreads slowly, vaccination efforts could possibly eliminate meningococcal disease in this area.

  • Use of Avian Bornavirus Isolates to Induce Proventricular Dilatation Disease in Conures PDF Version [PDF - 282 KB - 7 pages]
    P. Gray et al.
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    Avian bornavirus (ABV) is a newly discovered member of the family Bornaviridae that has been associated with the development of a lethal neurologic syndrome in birds, termed proventricular dilatation disease (PDD). We successfully isolated and characterized ABV from the brains of 8 birds with confirmed PDD. One isolate was passed 6 times in duck embryo fibroblasts, and the infected cells were then injected intramuscularly into 2 healthy Patagonian conures (Cyanoliseus patagonis). Clinical PDD developed in both birds by 66 days postinfection. PDD was confirmed by necropsy and histopathologic examination. Reverse transcription–PCR showed that the inoculated ABV was in the brains of the 2 infected birds. A control bird that received uninfected tissue culture cells remained healthy until it was euthanized at 77 days. Necropsy and histopathologic examinations showed no abnormalities; PCR did not indicate ABV in its brain tissues.

  • Economic Cost Analysis of West Nile Virus Outbreak, Sacramento County, California, USA, 2005 PDF Version [PDF - 237 KB - 7 pages]
    L. M. Barber et al.
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    In 2005, an outbreak of West Nile virus (WNV) disease occurred in Sacramento County, California; 163 human cases were reported. In response to WNV surveillance indicating increased WNV activity, the Sacramento-Yolo Mosquito and Vector Control District conducted an emergency aerial spray. We determined the economic impact of the outbreak, including the vector control event and the medical cost to treat WNV disease. WNV disease in Sacramento County cost ≈$2.28 million for medical treatment and patients’ productivity loss for both West Nile fever and West Nile neuroinvasive disease. Vector control cost ≈$701,790, including spray procedures and overtime hours. The total economic impact of WNV was $2.98 million. A cost-benefit analysis indicated that only 15 cases of West Nile neuroinvasive disease would need to be prevented to make the emergency spray cost-effective.


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