Dennis J Faix

Publications of Dennis J Faix

• Factors Associated with Loss of Penicillin G Concentrations in Serum after Intramuscular Benzathine Penicillin G Injection: A Meta-analysis.

  Authors: Michael P Broderick, Christian J Hansen, Dennis J Faix

  The Pediatric infectious disease journal. 04/2012;

  BACKGROUND:: An interval of 3-4 weeks between intramuscular injections of 1.2 million units of benzathine penicillin G (BGP) as prophylaxis against group A streptococcal infection is recommended byBACKGROUND:: An interval of 3-4 weeks between intramuscular injections of 1.2 million units of benzathine penicillin G (BGP) as prophylaxis against group A streptococcal infection is recommended by health organizations for patients with pediatric rheumatic fever and heart disease. METHODS:: We reviewed the literature for evidence of the persistence of serum penicillin G during the first 4 weeks following the recommended dose of BPG. RESULTS:: The weighted mean concentration was <0.02 μg/ml by 3 weeks after the initial dose. Weighted means were lower in studies done after 1990 than before (p<0.01), in studies dealing with secondary versus primary prophylaxis (p<0.01), and in studies in children vs. those in adults (p<0.02). CONCLUSION:: Recommendations for BPG prophylaxis may need re-evaluation.

• Decreased Serologic Response in Vaccinated Military Recruits during 2011 Correspond to Genetic Drift in Concurrent Circulating Pandemic A/H1N1 Viruses.

  Authors: Dennis J Faix, Anthony W Hawksworth, Christopher A Myers, Christian J Hansen, Ryan G Ortiguerra, Rebecca Halpin, David Wentworth, Laura A Pacha, Erica G Schwartz, Shawn M S Garcia, Angelia A Eick-Cost, Christopher D Clagett, Surender Khurana, Hana Golding, Patrick J Blair

  PloS one. 01/2012; 7(4):e34581.

  Population-based febrile respiratory illness surveillance conducted by the Department of Defense contributes to an estimate of vaccine effectiveness. Between January and March 2011, 64 cases of 2009Population-based febrile respiratory illness surveillance conducted by the Department of Defense contributes to an estimate of vaccine effectiveness. Between January and March 2011, 64 cases of 2009 A/H1N1 (pH1N1), including one fatality, were confirmed in immunized recruits at Fort Jackson, South Carolina, suggesting insufficient efficacy for the pH1N1 component of the live attenuated influenza vaccine (LAIV). To test serologic protection, serum samples were collected at least 30 days post-vaccination from recruits at Fort Jackson (LAIV), Parris Island (LAIV and trivalent inactivated vaccine [TIV]) at Cape May, New Jersey (TIV) and responses measured against pre-vaccination sera. A subset of 78 LAIV and 64 TIV sera pairs from recruits who reported neither influenza vaccination in the prior year nor fever during training were tested by microneutralization (MN) and hemagglutination inhibition (HI) assays. MN results demonstrated that seroconversion in paired sera was greater in those who received TIV versus LAIV (74% and 37%). Additionally, the fold change associated with TIV vaccination was significantly different between circulating (2011) versus the vaccine strain (2009) of pH1N1 viruses (ANOVA p value = 0.0006). HI analyses revealed similar trends. Surface plasmon resonance (SPR) analysis revealed that the quantity, IgG/IgM ratios, and affinity of anti-HA antibodies were significantly greater in TIV vaccinees. Finally, sequence analysis of the HA1 gene in concurrent circulating 2011 pH1N1 isolates from Fort Jackson exhibited modest amino acid divergence from the vaccine strain. Among military recruits in 2011, serum antibody response differed by vaccine type (LAIV vs. TIV) and pH1N1 virus year (2009 vs. 2011). We hypothesize that antigen drift in circulating pH1N1 viruses contributed to reduce vaccine effectiveness at Fort Jackson. Our findings have wider implications regarding vaccine protection from circulating pH1N1 viruses in 2011-2012.

• Serosurvey of bacterial and viral respiratory pathogens among deployed U.S. service members.

  Authors: Angelia A Eick, Dennis J Faix, Steven K Tobler, Remington L Nevin, Luther E Lindler, Zheng Hu, Jose L Sanchez, Victor H MacIntosh, Kevin L Russell, Joel C Gaydos

  American journal of preventive medicine. 12/2011; 41(6):573-80.

  Respiratory illnesses can cause substantial morbidity during military deployments. Bordetella pertussis, Chlamydia pneumoniae, Mycoplasma pneumoniae, adenovirus, parainfluenza, and respiratoryRespiratory illnesses can cause substantial morbidity during military deployments. Bordetella pertussis, Chlamydia pneumoniae, Mycoplasma pneumoniae, adenovirus, parainfluenza, and respiratory syncytial virus (RSV) are hypothesized causes. To determine pathogen-specific seroprevalence prior to and after deployment in support of Operation Enduring Freedom (OEF). A retrospective cohort study of 1000 service members deployed between June 30, 2004, and June 30, 2007, was conducted from 2008 through 2009. Pre- and post-deployment sera were tested for the presence of antibody to each pathogen. Pre-deployment IgG seropositivity was high for adenovirus, RSV, and parainfluenza (98.7%, 97.8%, and 81.6%, respectively), whereas seropositivity for B. pertussis, M. pneumoniae, and C. pneumoniae was 14.2%, 21.9%, and 65.1%, respectively. As defined by seroconversion in 1000 subjects, the following were identified: 43 new parainfluenza infections (24% of susceptibles); 37 new pertussis infections (4% of susceptibles); 33 new C. pneumoniae infections (10% of susceptibles); and 29 new M. pneumoniae infections (4% of susceptibles). B. pertussis seroconversion was two to four times higher than reports for the general U.S. population. Overall, 14.2% of the service members seroconverted to at least one of these six pathogens; this increased to 30.1% seroconversion when influenza was included. However, serologic testing was not clearly associated with clinical illness in this report. Serologic evidence for respiratory infections was common among the 2004-2007 OEF-deployed military, sometimes at a higher rate than the general U.S. population. Awareness of this risk and implementation of preventive measures should be emphasized by leadership prior to and during deployment.

• Dual infection of novel influenza viruses A/H1N1 and A/H3N2 in a cluster of Cambodian patients.

  Authors: Christopher A Myers, Matthew R Kasper, Chadwick Y Yasuda, Chin Savuth, David J Spiro, Rebecca Halpin, Dennis J Faix, Robert Coon, Shannon D Putnam, Thomas F Wierzba, Patrick J Blair

  The American journal of tropical medicine and hygiene. 11/2011; 85(5):961-3.

  During the early months of 2009, a novel influenza A/H1N1 virus (pH1N1) emerged in Mexico and quickly spread across the globe. In October 2009, a 23-year-old male residing in central Cambodia wasDuring the early months of 2009, a novel influenza A/H1N1 virus (pH1N1) emerged in Mexico and quickly spread across the globe. In October 2009, a 23-year-old male residing in central Cambodia was diagnosed with pH1N1. Subsequently, a cluster of four influenza-like illness cases developed involving three children who resided in his home and the children's school teacher. Base composition analysis of internal genes using reverse transcriptase polymerase chain reaction and electrospray ionization mass spectrometry revealed that specimens from two of the secondary victims were coinfected with influenza A/H3N2 and pH1N1. Phylogenetic analysis of the hemagglutinin genes from these isolated viruses showed that they were closely related to existing pH1N1 and A/H3N2 viruses circulating in the region. Genetic recombination was not evident within plaque-purified viral isolates on full genome sequencing. This incident confirms dual influenza virus infections and highlights the risk of zoonotic and seasonal influenza viruses to coinfect and possibly, reassort where they cocirculate.

• Knowledge, attitudes, and practice of travelers' diarrhea management among frontline providers.

  Authors: Aatif M Hayat, David R Tribble, John W Sanders, Dennis J Faix, Danny Shiau, Adam W Armstrong, Mark S Riddle

  Journal of travel medicine. 09/2011; 18(5):310-7.

  Many studies have found acute gastrointestinal infections to be among the most likely reason for clinic visits among forward deployed soldiers and are considered a significant contributor toMany studies have found acute gastrointestinal infections to be among the most likely reason for clinic visits among forward deployed soldiers and are considered a significant contributor to morbidity in this population. This occurs despite the controlled food and water distribution systems under which military populations operate. Furthermore, recent studies have indicated that providers often fail to appropriately identify and treat the typical causes of these infections. To adequately address this issue, an assessment of gaps in knowledge, practice, and management of acute diarrhea in deployed troops was conducted. A multiple-choice survey was developed by clinical researchers with expertise in travelers' diarrhea (TD) and provided to a convenience sample of clinical providers with a broad range of training and operational experience. The survey evaluated provider's knowledge of TD along with their ability to identify etiologies of various syndromic categories of acute gastrointestinal infections. Providers were also queried on selection of treatment approaches to a variety of clinical-based scenarios. A total of 117 respondents completed the survey. Most were aware of the standard definition of TD (77%); however, their knowledge about the epidemiology was lower, with less than 24% correctly answering questions on etiology of diarrhea, and 31% believing that a viral pathogen was the primary cause of watery diarrhea during deployment. Evaluation of scenario-based responses showed that 64% of providers chose not to use antibiotics to treat moderate TD. Furthermore, 19% of providers felt that severe inflammatory diarrhea was best treated with hydration only while 25% felt hydration was the therapy of choice for dysentery. Across all provider types, three practitioner characteristics appeared to be related to better scores on responses to the nine management scenarios: having a Doctor of Medicine or Doctor of Osteopathy degree, greater knowledge of TD epidemiology, and favorable attitudes toward antimotility or antibiotic therapy. Results from this survey support the need for improving knowledge and management of TD among deploying providers. The information from this study should be considered to support the establishment and dissemination of military diarrhea-management guidelines to assist in improving the health of military personnel.

• Possible reduced effectiveness of the 2009 H1N1 component of live, attenuated influenza vaccine.

  Authors: Christopher A Myers, Dennis J Faix, Patrick J Blair

  Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 07/2011; 53(2):207-8.

• Chlamydophila pneumoniae infection among Basic Underwater Demolition/SEAL (BUD/S) candidates, Coronado, California, July 2008.

  Authors: Robert G Coon, Melinda S Balansay, Dennis J Faix, Anthony W Hawksworth, Matthew B Patterson, Patrick J Blair

  Military medicine. 03/2011; 176(3):320-3.

  Community-acquired pneumonia can compromise readiness of recruits and service members operating in confined spaces. Often respiratory pathogens are implicated in outbreaks. In July 2008, 5 BasicCommunity-acquired pneumonia can compromise readiness of recruits and service members operating in confined spaces. Often respiratory pathogens are implicated in outbreaks. In July 2008, 5 Basic Underwater Demolition/SEAL students entering an intense period of training at Naval Amphibious Base Coronado reported with clinical symptoms and chest radiographs consistent with pneumonia. Throat and nasal swabs were tested for respiratory pathogens. Molecular evidence indicated that they were infected with the atypical bacterium Chlamydophila pneumoniae. Thirty contemporaneous Basic Underwater Demolition/SEAL students were tested to determine the extent of C pneumoniae infection burden. Five additional cases were captured within this group. The 10 individuals diagnosed with C pneumoniae were treated with a course of azithromycin, Avelox (moxifloxacin hydrochloride), and doxycycline. The cases ended following the isolation of cases and prophylaxis with oral antibiotics. This work highlights the importance of rapid respiratory disease diagnoses to guide the clinical response following the emergence of respiratory infections among military trainees.

• Outbreak of pneumonia in the setting of fatal pneumococcal meningitis among US Army trainees: potential role of Chlamydia pneumoniae infection.

  Authors: Fatimah S Dawood, John F Ambrose, Bruce P Russell, Anthony W Hawksworth, Jonas M Winchell, Nina Glass, Kathleen Thurman, Michele A Soltis, Erin McDonough, Agnes K Warner, Emily Weston, Nakia S Clemmons, Jennifer Rosen, Stephanie L Mitchell, Dennis J Faix, Patrick J Blair, Matthew R Moore, John Lowery

  BMC infectious diseases. 01/2011; 11:157.

  Compared to the civilian population, military trainees are often at increased risk for respiratory infections. We investigated an outbreak of radiologically-confirmed pneumonia that was recognizedCompared to the civilian population, military trainees are often at increased risk for respiratory infections. We investigated an outbreak of radiologically-confirmed pneumonia that was recognized after 2 fatal cases of serotype 7F pneumococcal meningitis were reported in a 303-person military trainee company (Alpha Company). We reviewed surveillance data on pneumonia and febrile respiratory illness at the training facility; conducted chart reviews for cases of radiologically-confirmed pneumonia; and administered surveys and collected nasopharyngeal swabs from trainees in the outbreak battalion (Alpha and Hotel Companies), associated training staff, and trainees newly joining the battalion. Among Alpha and Hotel Company trainees, the average weekly attack rates of radiologically-confirmed pneumonia were 1.4% and 1.2% (most other companies at FLW: 0-0.4%). The pneumococcal carriage rate among all Alpha Company trainees was 15% with a predominance of serotypes 7F and 3. Chlamydia pneumoniae was identified from 31% of specimens collected from Alpha Company trainees with respiratory symptoms. Although the etiology of the outbreak remains unclear, the identification of both S. pneumoniae and C. pneumoniae among trainees suggests that both pathogens may have contributed either independently or as cofactors to the observed increased incidence of pneumonia in the outbreak battalion and should be considered as possible etiologies in outbreaks of pneumonia in the military population.

• A growing global network's role in outbreak response: AFHSC-GEIS 2008-2009.

  Authors: Matthew C Johns, Ronald L Burke, Kelly G Vest, Mark Fukuda, Julie A Pavlin, Sanjaya K Shrestha, David C Schnabel, Steven Tobias, Jeffrey A Tjaden, Joel M Montgomery [......] David Metzgar, Anthony Hawksworth, Patrick Blair, Melody Ellorin, Robert Coon, Victor Macintosh, Kristen Burwell, Elizabeth Macias, Thomas Palys, Kurt Jerke

  BMC public health. 01/2011; 11 Suppl 2:S3.

  A cornerstone of effective disease surveillance programs comprises the early identification of infectious threats and the subsequent rapid response to prevent further spread. Effectively identifying,A cornerstone of effective disease surveillance programs comprises the early identification of infectious threats and the subsequent rapid response to prevent further spread. Effectively identifying, tracking and responding to these threats is often difficult and requires international cooperation due to the rapidity with which diseases cross national borders and spread throughout the global community as a result of travel and migration by humans and animals. From Oct.1, 2008 to Sept. 30, 2009, the United States Department of Defense's (DoD) Armed Forces Health Surveillance Center Global Emerging Infections Surveillance and Response System (AFHSC-GEIS) identified 76 outbreaks in 53 countries. Emerging infectious disease outbreaks were identified by the global network and included a wide spectrum of support activities in collaboration with host country partners, several of which were in direct support of the World Health Organization's (WHO) International Health Regulations (IHR) (2005). The network also supported military forces around the world affected by the novel influenza A/H1N1 pandemic of 2009. With IHR (2005) as the guiding framework for action, the AFHSC-GEIS network of international partners and overseas research laboratories continues to develop into a far-reaching system for identifying, analyzing and responding to emerging disease threats.

• Serum penicillin G levels are lower than expected in adults within two weeks of administration of 1.2 million units.

  Authors: Michael P Broderick, Christian J Hansen, Kevin L Russell, Edward L Kaplan, Jeffrey L Blumer, Dennis J Faix

  PloS one. 01/2011; 6(10):e25308.

  When introduced in the 1950s, benzathine penicillin G (BPG) was shown to be effective in eradicating group A beta-hemolytic streptococcus (GAS) for at least 3 weeks after administration. SeveralWhen introduced in the 1950s, benzathine penicillin G (BPG) was shown to be effective in eradicating group A beta-hemolytic streptococcus (GAS) for at least 3 weeks after administration. Several studies since the 1990s suggest that at 3-4 weeks serum penicillin G levels are less than adequate (below MIC(90) of 0.016 µg/ml). We studied these levels for 4 weeks after the recommended dose of BPG in military recruits, for whom it is used as prophylaxis against GAS. The 329 subjects (mean age 20 years) each received 1.2 million units BPG IM and gave sera 1 day post injection and twice more at staggered time points over 4 weeks. Serum penicillin G levels were measured by liquid chromatography/tandem mass spectometry. The half-life of serum penicillin G was 4.1 days. By day 11, mean levels were <0.02 µg/ml, and by day 15<0.01 µg/ml. Levels in more than 50% of the subjects were below 0.02 µg/ml on day 9, and <.01 µg/ml on day 16. There was no demonstrable effect of subject body-surface area nor of the four different lots of BPG used. These data indicate that in healthy young adults serum penicillin G levels become less than protective <2½ weeks after injection of 1.2 million units of BPG. The findings require serious consideration in future medical and public health recommendations for treatment and prophylaxis of GAS upper respiratory tract infections.

• Initial identification and characterization of an emerging zoonotic influenza virus prior to pandemic spread.

  Authors: David Metzgar, Darcie Baynes, Christopher A Myers, Peter Kammerer, Michelle Unabia, Dennis J Faix, Patrick J Blair

  Journal of clinical microbiology. 11/2010; 48(11):4228-34.

  Two cases of febrile respiratory illness associated with untypeable influenza A virus were identified in Southern California in March 2009. One was initially detected as influenza virus using anTwo cases of febrile respiratory illness associated with untypeable influenza A virus were identified in Southern California in March 2009. One was initially detected as influenza virus using an experimental diagnostic device in a clinical trial, while the other was detected at a local reference lab using a diagnostic PCR assay. In both cases, analyses yielded negative results for strain-specific tests targeting circulating strains of influenza A virus (seasonal H1 and H3). These two samples became the first reported cases of the pandemic 2009/H1N1 influenza virus. The first reportable characterization was made from the second collected specimen on 15 April 2009 at the Centers for Disease Control and Prevention central lab using traditional culture and sequencing methods. The novel nature of the strain and its apparent zoonotic origins were initially characterized using the first collected specimen at the Naval Health Research Center in San Diego, CA, on 13 April using an experimental molecular analysis tool, PCR electro-spray ionization-mass spectrometry (PCR/ESI-MS), designed to amplify PCR products from any strain of influenza virus and to generate informative (phylogenetic) strain identifications through mass spectrometry of PCR amplicons. The ability of this high-throughput tool to correctly identify both well-characterized and novel influenza strains offers the possibility to integrate surveillance for emerging strains with on-site rapid diagnosis used for patient management, shortening the times between the emergence of new strains, their detection and identification, and appropriate public health response activities. Here we describe the initial characterization of the pandemic 2009/H1N1 influenza strain and discuss the possible roles of diagnostic tools with discovery potential.

• Triple combination of amantadine, ribavirin, and oseltamivir is highly active and synergistic against drug resistant influenza virus strains in vitro.

  Authors: Jack T Nguyen, Justin D Hoopes, Minh H Le, Donald F Smee, Amy K Patick, Dennis J Faix, Patrick J Blair, Menno D de Jong, Mark N Prichard, Gregory T Went

  PloS one. 01/2010; 5(2):e9332.

  The rapid emergence and subsequent spread of the novel 2009 Influenza A/H1N1 virus (2009 H1N1) has prompted the World Health Organization to declare the first pandemic of the 21st century,The rapid emergence and subsequent spread of the novel 2009 Influenza A/H1N1 virus (2009 H1N1) has prompted the World Health Organization to declare the first pandemic of the 21st century, highlighting the threat of influenza to public health and healthcare systems. Widespread resistance to both classes of influenza antivirals (adamantanes and neuraminidase inhibitors) occurs in both pandemic and seasonal viruses, rendering these drugs to be of marginal utility in the treatment modality. Worldwide, virtually all 2009 H1N1 and seasonal H3N2 strains are resistant to the adamantanes (rimantadine and amantadine), and the majority of seasonal H1N1 strains are resistant to oseltamivir, the most widely prescribed neuraminidase inhibitor (NAI). To address the need for more effective therapy, we evaluated the in vitro activity of a triple combination antiviral drug (TCAD) regimen composed of drugs with different mechanisms of action against drug-resistant seasonal and 2009 H1N1 influenza viruses. Amantadine, ribavirin, and oseltamivir, alone and in combination, were tested against amantadine- and oseltamivir-resistant influenza A viruses using an in vitro infection model in MDCK cells. Our data show that the triple combination was highly synergistic against drug-resistant viruses, and the synergy of the triple combination was significantly greater than the synergy of any double combination tested (P<0.05), including the combination of two NAIs. Surprisingly, amantadine and oseltamivir contributed to the antiviral activity of the TCAD regimen against amantadine- and oseltamivir-resistant viruses, respectively, at concentrations where they had no activity as single agents, and at concentrations that were clinically achievable. Our data demonstrate that the TCAD regimen composed of amantadine, ribavirin, and oseltamivir is highly synergistic against resistant viruses, including 2009 H1N1. The TCAD regimen overcomes baseline drug resistance to both classes of approved influenza antivirals, and thus may represent a highly active antiviral therapy for seasonal and pandemic influenza.

• An Outbreak of Acute Respiratory Disease Caused by Mycoplasma pneumoniae Onboard a Deployed US Navy Ship.

  Authors: Joseph A. Sliman, David Metzgar, David C. Asseff, Robert G Coon, Dennis J Faix, Stephen Lizewski

  Journal of clinical microbiology. 10/2009;

  We identified 179 cases of acute respiratory illness including 50 cases of radiographically-confirmed pneumonia over the course of four months on a deployed US Navy vessel. Laboratory tests showedWe identified 179 cases of acute respiratory illness including 50 cases of radiographically-confirmed pneumonia over the course of four months on a deployed US Navy vessel. Laboratory tests showed Mycoplasma pneumoniae to be the etiological agent. This report represents the first published description of a shipboard outbreak of this pathogen.

• Rapid-Test Sensitivity for Novel Swine-Origin Influenza A (H1N1) Virus in Humans.

  Authors: Dennis J Faix, Sterling S Sherman, Steven H Waterman

  The New England journal of medicine. 07/2009;

• Outbreak of Severe Respiratory Disease Associated with Emergent Human Adenovirus Serotype 14 at a US Air Force Training Facility in 2007.

  Authors: Jacqueline E Tate, Michel L Bunning, Lisa Lott, Xiaoyan Lu, John Su, David Metzgar, Lorie Brosch, Catherine A Panozzo, Vincent C Marconi, Dennis J Faix, Mila Prill, Brian Johnson, Dean D Erdman, Vincent Fonseca, Larry J Anderson, Marc-Alain Widdowson

  The Journal of infectious diseases. 05/2009;

  Background. In 2007, a US Air Force training facility reported a cluster of severe respiratory illnesses associated with a rare human adenovirus (Ad) serotype, Ad14. We investigated this outbreak toBackground. In 2007, a US Air Force training facility reported a cluster of severe respiratory illnesses associated with a rare human adenovirus (Ad) serotype, Ad14. We investigated this outbreak to better understand its epidemiology, clinical spectrum, and associated risk factors. Methods. Data were collected from ongoing febrile respiratory illness (FRI) surveillance and from a retrospective cohort investigation. Because an Ad7 vaccine is in development, Ad7 antibody titers in pretraining serum samples from trainees with mild and those with severe Ad14 illness were compared. Results. During 2007, an estimated 551 (48%) of 1147 trainees with FRI were infected with Ad14; 23 were hospitalized with pneumonia, 4 required admission to an intensive care unit, and 1 died. Among cohort members ([Formula: see text]), the Ad14 infection rate was high (50%). Of those infected, 40% experienced FRI. No cohort members were hospitalized. Male sex (risk ratio [RR], 4.7 [95% confidence interval {CI}, 2.2-10.1]) and an ill close contact (RR, 1.6 [95% CI, 1.2-2.2]) were associated with infection. Preexisting Ad7 neutralizing antibodies were found in 7 (37%) of 19 Ad14-positive trainees with mild illness but in 0 of 16 trainees with Ad14 pneumonia ([Formula: see text]). Conclusions. Emergence of Ad14, a rare Ad serotype, caused a protracted outbreak of respiratory illness among military recruits. Most infected recruits experienced FRI or milder illnesses. Some required hospitalization, and 1 died. Natural Ad7 infection may protect against severe Ad14 illness.

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• Inference of antibiotic resistance and virulence among diverse group A Streptococcus strains using emm sequencing and multilocus genotyping methods.

  Authors: David Metzgar, Darcie Baynes, Christian J Hansen, Erin A McDonough, Daisy R Cabrera, Melody M Ellorin, Patrick J Blair, Kevin L Russell, Dennis J Faix

  PloS one. 02/2009; 4(9):e6897.

  BACKGROUND: Group A Streptococcus pyogenes (GAS) exhibits a high degree of clinically relevant phenotypic diversity. Strains vary widely in terms of antibiotic resistance (AbR), clinical severity,BACKGROUND: Group A Streptococcus pyogenes (GAS) exhibits a high degree of clinically relevant phenotypic diversity. Strains vary widely in terms of antibiotic resistance (AbR), clinical severity, and transmission rate. Currently, strain identification is achieved by emm typing (direct sequencing of the genomic segment coding for the antigenic portion of the M protein) or by multilocus genotyping methods. Phenotype analysis, including critical AbR typing, is generally achieved by much slower and more laborious direct culture-based methods. METHODOLOGY/PRINCIPAL FINDINGS: We compare genotype identification (by emm typing and PCR/ESI-MS) with directly measured phenotypes (AbR and outbreak associations) for 802 clinical isolates of GAS collected from symptomatic patients over a period of 6 years at 10 military facilities in the United States. All independent strain characterization methods are highly correlated. This shows that recombination, horizontal transfer, and other forms of reassortment are rare in GAS insofar as housekeeping genes, primary virulence and antibiotic resistance determinants, and the emm gene are concerned. Therefore, genotyping methods offer an efficient way to predict emm type and the associated AbR and virulence phenotypes. CONCLUSIONS/SIGNIFICANCE: The data presented here, combined with much historical data, suggest that emm typing assays and faster molecular methods that infer emm type from genomic signatures could be used to efficiently infer critical phenotypic characteristics based on robust genotype: phenotype correlations. This, in turn, would enable faster and better-targeted responses during identified outbreaks of constitutively resistant or particularly virulent emm types.

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• Outbreak of Q fever among US military in western Iraq, June-July 2005.

  Authors: Dennis J Faix, Dustin J Harrison, Mark S Riddle, Andrew F Vaughn, Samuel L Yingst, Kenneth Earhart, Glenn Thibault

  Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 05/2008; 46(7):e65-8.

  An outbreak of Q fever occurred in 22 (58%) of 38 Marines deployed to Iraq in 2005. Fever (in 100% of patients), respiratory symptoms (76%), and gastrointestinal symptoms (53%) were common. PossibleAn outbreak of Q fever occurred in 22 (58%) of 38 Marines deployed to Iraq in 2005. Fever (in 100% of patients), respiratory symptoms (76%), and gastrointestinal symptoms (53%) were common. Possible risk factors included dust and exposure to animals and ticks.

• Traveler's diarrhea in Thailand: randomized, double-blind trial comparing single-dose and 3-day azithromycin-based regimens with a 3-day levofloxacin regimen.

  Authors: David R Tribble, John W Sanders, Lorrin W Pang, Carl Mason, Chittima Pitarangsi, Shahida Baqar, Adam Armstrong, Paul Hshieh, Anne Fox, Elisabeth A Maley, Carlos Lebron, Dennis J Faix, James V Lawler, Gautam Nayak, Michael Lewis, Ladaporn Bodhidatta, Daniel A Scott

  Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 03/2007; 44(3):338-46.

  BACKGROUND: Traveler's diarrhea in Thailand is frequently caused by Campylobacter jejuni. Rates of fluoroquinolone (FQ) resistance in Campylobacter organisms have exceeded 85% in recent years, andBACKGROUND: Traveler's diarrhea in Thailand is frequently caused by Campylobacter jejuni. Rates of fluoroquinolone (FQ) resistance in Campylobacter organisms have exceeded 85% in recent years, and reduced fluoroquinolone efficacy has been observed. METHODS: Azithromycin regimens were evaluated in a randomized, double-blind trial of azithromycin, given as a single 1-g dose or a 3-day regimen (500 mg daily), versus a 3-day regimen of levofloxacin (500 mg daily) in military field clinics in Thailand. Outcomes included clinical end points (time to the last unformed stool [TLUS] and cure rates) and microbiological end points (pathogen eradication). RESULTS: A total of 156 patients with acute diarrhea were enrolled in the trial. Campylobacter organisms predominated (in 64% of patients), with levofloxacin resistance noted in 50% of Campylobacter organisms and with no azithromycin resistance noted. The cure rate at 72 h after treatment initiation was highest (96%) with single-dose azithromycin, compared with the cure rates of 85% noted with 3-day azithromycin and 71% noted with levofloxacin (P=.002). Single-dose azithromycin was also associated with the shortest median TLUS (35 h; P=.03, by log-rank test). Levofloxacin's efficacy was inferior to azithromycin's efficacy, except in patients with no pathogen identified during the first 24 h of treatment or in patients with levofloxacin-susceptible Campylobacter isolates, in whom it appeared to be equal to azithromycin. The rate of microbiological eradication was significantly better with azithromycin-based regimens (96%-100%), compared with levofloxacin (38%) (P=.001); however, this finding was poorly correlated with clinical outcome. A higher rate of posttreatment nausea in the 30 min after receipt of the first dose (14% vs. <6%; P=.06) was observed as a mild, self-limited complaint associated with single-dose azithromycin. CONCLUSIONS: Single-dose azithromycin is recommended for empirical therapy of traveler's diarrhea acquired in Thailand and is a reasonable first-line option for empirical management in general.

• Epidemic infectious gastrointestinal illness aboard U.S. Navy ships deployed to the Middle East during peacetime operations--2000-2001.

  Authors: Mark S Riddle, Bonnie L Smoak, Scott A Thornton, Joseph S Bresee, Dennis J Faix, Shannon D Putnam

  BMC gastroenterology. 02/2006; 6:9.

  BACKGROUND: Infectious gastrointestinal illness (IGI) outbreaks have been reported in U.S. Navy ships and could potentially have an adverse mission impact. Studies to date have been anecdotal.BACKGROUND: Infectious gastrointestinal illness (IGI) outbreaks have been reported in U.S. Navy ships and could potentially have an adverse mission impact. Studies to date have been anecdotal. METHODS: We conducted a retrospective analysis of weekly reported disease and non-battle injury health data collected in 2000-2001 from 44 U.S. Navy ships while sailing in the 5th Fleet (Persian Gulf and nearby seas). RESULTS: During this period, 11 possible IGI outbreaks were identified. Overall, we found 3.3 outbreaks per 100 ship-weeks, a mean outbreak duration of 4.4 weeks, and a mean cumulative ship population attack rate of 3.6%. Morbidity, represented by days lost due to personnel being placed on sick-in-quarters status, was higher during outbreak weeks compared to non-outbreak weeks (p = 0.002). No clear seasonal distribution was identified. CONCLUSION: Explosive outbreaks due to viruses and bacteria with the potential of incapacitating large proportions of the crew raise serious concerns of mission impact and military readiness.

• Evaluation of a rapid quantitative diagnostic test for adenovirus type 4.

  Authors: Dennis J Faix, Huo-Shu H Houng, Joel C Gaydos, Shih-Kang S Liu, John T Connors, Xiomara Brown, Ludmila V Asher, David W Vaughn, Leonard N Binn

  Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 02/2004; 38(3):391-7.

  Acute respiratory disease (ARD) due to adenoviruses is a reemerging disease in military recruits. It is a challenge for clinicians to accurately diagnose this disease and to appropriately treatAcute respiratory disease (ARD) due to adenoviruses is a reemerging disease in military recruits. It is a challenge for clinicians to accurately diagnose this disease and to appropriately treat affected individuals. This study investigated the utility of a quantitative, rapid-cycle, real-time fluorogenic polymerase chain reaction (PCR) technique for detecting adenovirus type 4 (Ad4) in a clinical setting. Throat swab specimens and clinical data were collected from US Army basic trainees hospitalized with ARD at Fort Jackson, South Carolina. A total of 140 throat swab specimens were collected from 83 subjects. Rapid PCR results (obtained in <2 h) had a sensitivity of 100% and a specificity of 100%, compared with viral culture. There was no difference, qualitative or quantitative, between frozen and fresh samples for PCR detection of Ad4. Individuals with test results positive for Ad4 were hospitalized longer than were individuals with negative test results. Higher virus loads at hospital admission corresponded to longer lengths of stay for Ad4-positive subjects.