Evaluation of PCR testing of ethanol-fixed nasal swab specimens as an augmented surveillance strategy for influenza virus and adenovirus identification.

Viral culture isolation has been widely accepted as the "gold standard" for laboratory confirmation of viral infection; however, it requires ultralow temperature specimen storage. Storage of specimens in ethanol at room temperature could expand our ability to conduct active surveillance and retrospective screenings of viruses with rapid and inexpensive real-time PCR tests, including isolates from remote regions where freezing specimens for culture is not feasible. Molecular methods allow for rapid identification of viral pathogens without the need to maintain viability. We hypothesized that ethanol, while inactivating viruses, can preserve DNA and RNA for PCR-based methods. To evaluate the use of ethanol-stored specimens for augmenting surveillance for detection of influenza viruses A and B and adenoviruses (AdV), paired nasal swab specimens were collected from 384 recruits with febrile respiratory illness at Fort Jackson, S.C., in a 2-year study. One swab was stored at ambient temperature in 100% ethanol for up to 6 months, and the other swab was stored at -70 degrees C in viral medium. For viral detection, frozen specimens were cultured for a variety of respiratory viruses, and ethanol-fixed specimens were tested with TaqMan (TM) probe and LightCycler SYBR green (SG) melting curve assays with at least two different PCR targets for each virus. The sensitivities of the TM and SG assays on specimens stored in ethanol for 1 month were 75% and 58% for influenza A, 89% and 67% for influenza B, and 93 to 98% and 57% for AdV, respectively. Lower specificities of the real-time assays corresponded to the increased detection of PCR-positive but culture-negative specimens. Influenza virus RNA was detected as well or better after 6 months of storage in ethanol.

Preference among female Army recruits for use of self-administrated vaginal swabs or urine to screen for Chlamydia trachomatis genital infections.

BACKGROUND: Use of self-administered vaginal swabs (SAS) for the detection of Chlamydia trachomatis by nucleic acid amplification tests simplifies specimen collection and transport, especially for women in nonclinical settings. GOAL: We investigated the preference and comfort level of military women for the collection of SAS, compared with urine, for the diagnosis of genital chlamydial infections. STUDY DESIGN: During March through August 1999, female Army recruits in basic training at Fort Jackson, South Carolina, were invited to participate in the study. Participants were requested to complete a questionnaire after providing both first-void urine (FVU) and SAS specimens. Participant characteristics, preferences, and comfort levels were assessed using multivariate logistic regression. RESULTS: From 4496 eligible female recruits, 1403 (31%) completed questionnaires and 1382 provided both specimens; 11.8% (166 of 1403) of participants were infected with chlamydia. The relative sensitivity and specificity of the C. trachomatis Ligase Chain Reaction test on SAS in 1382 matched pairs was 81.1% and 98.6%, respectively, using the test result on urine specimens as the comparison standard. Most of the participants (90.8%) reported that they felt comfortable collecting the FVU specimen, and 69.6% indicated that they felt comfortable collecting SAS. Either specimen collection type received high acceptability at home and in the field, and more women reported that they would collect FVU than reported they would collect SAS in the future (in the field: FVU: 79.4%, SAS: 68.8%, P <0.001); at home: FVU: 90.9%, SAS: 82.9%, P <0.001). When questioned about ease of use, 60.4% of women reported that urine was the easier method. Preferences for SAS were associated with being white and having had sexual risk behaviors in the past 3 months. CONCLUSION: A study of preferences for urine versus self-administered vaginal swabs for the detection of C. trachomatis in military women showed that women generally found SAS acceptable. SAS should be a feasible alternative to urine collection in situations in which specimen storage or transport is an issue.

Geographic epidemiology of gonorrhoea and chlamydia on a large military installation: application of a GIS system.

OBJECTIVES: The geographic epidemiology of infectious diseases can help in identifying point source outbreaks, elucidating dispersion patterns, and giving direction to control strategies. We sought to establish a geographic information system (GIS) infectious disease surveillance system at a large US military post (Fort Bragg, North Carolina) using STDs as the initial outcome for the model. METHODS: Addresses of incident cases were plotted onto digitised base maps of Fort Bragg (for on-post addresses) and surrounding Cumberland County, NC (for off-post addresses) using MAPINFO Version 5. We defined 26 geographic sectors on the installation. Active duty soldiers attending the post preventive medicine clinic were enrolled between July 1998 and June 1999. RESULTS: Gonorrhoea (GC) was diagnosed in 210/2854 (7.4%) and chlamydia (CT) in 445/2860 (15.6%). African-American male soldiers were at higher risk for GC (OR = 4.6 (95% CL 3.0 to 7.2)) and chlamydia (OR = 2.0 (1.4 to 2.7)). For women, there were no ethnic differences in gonorrhoea prevalence, but chlamydia was higher in African-Americans (OR = 2.0 (1.4-2.7)). Rank and housing type were associated with gonorrhoea and chlamydia in men, but were not significant factors in women. For gonorrhoea, two geographic sectors had prevalences between 14.0%-16.5%, three between 10.3%-13.9%, three between 7.1%-10.2%, and five between 3.0%-7.1%. The geographic distribution demonstrated a core-like pattern where the highest sectors were contiguous and were sectors containing barracks housing lower enlisted grade personnel. In contrast, chlamydia prevalence was narrowly distributed. CONCLUSION: GIS based disease surveillance was easily and rapidly implemented in this setting and should be useful in developing preventive interventions.

Features of Chlamydia trachomatis and Neisseria gonorrhoeae infection in male Army recruits.

Non-health care-seeking male United States Army recruits were tested for Chlamydia trachomatis (n=2245) and Neisseria gonorrhoeae (n=884), using a urine ligase chain reaction test to determine prevalence and potential risk factors for infection. The prevalence of chlamydial infection was 5.3%. Black race, a new sex partner, a history of trichomonas, and the presence of symptoms were associated with chlamydial infection. The prevalence of N. gonorrhoeae infection was 0.6%. Only a reported history of or positive test for C. trachomatis was associated with gonorrheal infection. Of those testing positive for chlamydia, 14% reported symptoms versus 40% of those with gonorrhea. Younger age was not a predictor of either infection, as has been shown for women. A substantial number of male army recruits are infected with C. trachomatis, but few are infected with N. gonorrhoeae. Screening on the basis of symptoms alone would miss the majority of both infections.

Evaluation of use of a single intravaginal swab to detect multiple sexually transmitted infections in active-duty military women.

The accuracy and suitability of use of a single intravaginal swab (SIS) for polymerase chain reaction detection of Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, and human papillomavirus infection was assessed in a cross-sectional study of 841 active-duty military women. The SIS, compared with standard diagnostic tests, allowed detection of more gonorrhea, more chlamydial infection, and more trichomoniasis. Sensitivity and specificity of SIS detection compared with adjudicated true-positive diagnoses were 95.8% and 97.8%, respectively, for gonorrhea, 94.6% and 99.3% for chlamydial infection, and 92.2% and 98.2% for trichomonal infection. Results with SISs were comparable to those with cervical swabs tested for human papillomavirus. Assay of clinician-collected and self-collected SISs yielded prevalences similar to those of standard diagnostic tests for all sexually transmitted infections. Therefore, the use of SISs is acceptable for the simultaneous diagnosis of multiple sexually transmitted infections and has potential for use as a self-administered diagnostic tool with widespread applicability among women.

Diagnosis of human papillomavirus infection by dry vaginal swabs in military women.

OBJECTIVE: Human papillomavirus (HPV) assays are likely to be used with increasing frequency in clinical management of women with abnormal Papanicolaou smears and in cervical cancer screening. Our objective was to simplify the method of collection of female genital tract specimens. The utility of vaginal dry swabs for HPV diagnosis was evaluated. METHODS: Specimens for cytology and for HPV identification were collected by a clinician from 189 female soldiers attending a military clinic. Three methods of specimen collection for HPV identification were compared: a vaginal dry swab (v-DRY), and vaginal and cervical swabs placed into specimen transport medium (v-STM and c-STM). Swabs were shipped to a STD laboratory for processing. Specific HPV types were identified by a consensus primer based PCR based method. Results from 165 women were evaluable. RESULTS: HPV prevalence by the three methods was similar and ranged from 44.8% to 50.9%. 53 (32.1%) women were HPV positive and 60 (36.4%) women were HPV negative by all three collection methods. With respect to the risk categories of specific HPV types, there was greater agreement between the results from the two vaginal (v-DRY and v-STM) samples (kappa values of 0.69-0.81) than between the cervical (c-STM) and either of the vaginal samples (kappa values of 0.37-0.55). The HPV yield from c-STM was somewhat greater than that from the vaginal specimens but the correlation between cytological abnormalities and HPV was high for all three methods. CONCLUSION: A dry vaginal swab may be an acceptable method of specimen collection for HPV diagnosis.

Point-of-entry screening for C. trachomatis In female army recruits. Who derives the cost savings?

BACKGROUND: Screening women for genital Chlamydia trachomatis at entry to military service provides an opportunity to reduce costs associated with sequelae of this infection. However, financial responsibility for screening may be debated. More than 50% of recruits return to civilian life within 2 years. The military and the civilian health care systems would both benefit from a screening program. OBJECTIVE: To assess the cost-effectiveness and relative cost savings to the military and civilian health sectors of three screening strategies for U.S. Army female recruits for C. trachomatis using urine ligase chain reaction: screening all recruits, screening recruits aged < or = 25 years, and no screening. METHODS: We applied a decision analytic model. Cost factors included screening, lost military training, morbid pelvic inflammatory disease, and other sequelae. Using a 5-year analytic horizon, we conducted analyses from military and civilian perspectives. RESULTS: Screening 10,000 female army recruits would cost 193,500 dollars and prevent 282 cases of sequelae, with a projected savings of 53,325 dollars to the military and 505,053 dollars to the civilian sector. From a military perspective, screening women aged < or = 25 years provided the highest cost savings. Screening all female recruits incurred an incremental cost of $1199 per sequela prevented. From a civilian perspective, screening all recruits offered the greatest cost savings. CONCLUSIONS: Screening female Army recruits for C. trachomatis offers substantial savings in health care costs for both the military and civilian health care systems. Relative financial benefit derived from recruit screening is disproportionate; greatest cost savings are enjoyed by the civilian sector.

The need for a military public health laboratory symposium.

The Department of Defense Global Emerging Infections Surveillance and Response System has a mission to identify vulnerabilities in the military health system related to the occurrence of emerging infectious diseases. Public health laboratory (PHL) functions are critical to the detection and control of emerging infectious diseases and were assessed. Four important services were evaluated: (1) surveillance for antibiotic resistance, (2) laboratory-based infectious disease surveillance, (3) provision of diagnostic services for uncommon infections, and (4) specimen referral and information transfer within a defined PHL infrastructure. Initial assessments identified several shortcomings and a lack of information about PHL functions. Therefore, a PHL symposium was held in September 1999 to define the state of civilian and military PHL functions, identify problems and interventions, and encourage civilian-military networking. After the symposium, selected attendees met in two workshop groups. One addressed the first two functions; the other addressed the last two.

The Department of Defense laboratory-based global influenza surveillance system.

Military global influenza surveillance began in 1976 as an Air Force program. In 1997, the Department of Defense (DoD) Global Emerging Infections Surveillance and Response System expanded the program to include all services. Also included were local residents in areas where DoD overseas research activities operated. This new, worldwide DoD surveillance infrastructure provides valuable information and can respond quickly to outbreaks. This was demonstrated during the current influenza season when a suspected outbreak was reported in Panama. In less than 3 weeks, specimens were collected, transported, and cultured, and isolates were subtyped and sent to the Centers for Disease Control and Prevention for further studies. This influenza surveillance initiative combines viral isolation, antigenic characterization, and molecular sequencing with clinical and public health management of information. The information obtained is shared with the Centers for Disease Control and Prevention and the World Health Organization and has contributed to important decisions in influenza vaccine composition.

Epidemic spread of adenovirus type 4-associated acute respiratory disease between U.S. Army installations.

A large outbreak of adenovirus type 4-associated acute respiratory disease (ARD) occurred at Fort Jackson, South Carolina, in 1997. A laboratory-based ARD surveillance program was initiated at Fort Gordon, Georgia, where advanced individual training was heavily populated with Fort Jackson soldiers. Adenovirus type 4 was isolated from 50% of 147 trainees hospitalized with ARD. Most (88%) introduced cases were in trainees from Fort Jackson.

Cost-effectiveness analysis of reacquiring and using adenovirus types 4 and 7 vaccines in naval recruits.

Adenovirus vaccines have controlled acute respiratory disease (ARD) in military recruits since 1971. Vaccine production, however, ceased and new facilities are required. We assessed whether reacquiring and using vaccines in naval recruits is cost-effective. Three policy options were evaluated: no vaccination, seasonal vaccination, and year-round vaccination. Morbidity (outpatient and inpatient), illness costs (medical and lost training), and vaccine program costs (start-up, acquisition, and distribution) were modeled using a decision-analytic method. Results were based on a cohort of 49,079 annual trainees, a winter vaccine-preventable ARD rate of 2.6 cases per 100 person-weeks, a summer incidence rate at 10% of the winter rate, a hospitalization rate of 7.6%, and a production facility costing US$12 million. Compared to no vaccination, seasonal vaccination prevented 4,015 cases and saved $2.8 million per year. Year-round vaccination prevented 4,555 cases and saved $2.6 million. Reacquiring and using adenovirus vaccines seasonally or year-round saves money and averts suffering.

Large, persistent epidemic of adenovirus type 4-associated acute respiratory disease in U.S. army trainees.

In May 1997, a large, persistent epidemic of adenovirus type 4-associated acute respiratory disease began at Fort Jackson, South Carolina, the largest army basic training center. The epidemic lasted until December and declined when vaccine administration resumed. More than 1,000 male and female trainees were hospitalized; 66.1% of those hospitalized had an adenovirus type 4 isolate.

Control of Chlamydia trachomatis infections in female army recruits: cost-effective screening and treatment in training cohorts to prevent pelvic inflammatory disease.

CONTEXT: Chlamydia trachomatis genitourinary infections in females can lead to serious and costly sequelae. Programs such as basic (initial entry) military training with controlled points of entry offer an opportunity to screen large cohorts of women at risk for infection. OBJECTIVE: To assess the cost-effectiveness of three interventions for C. trachomatis infections in women beginning Army training: 1) screening using urine ligase chain reaction (LCR) by age, 2) unrestricted testing using urine LCR, and 3) universal antibiotic treatment with azithromycin. DESIGN: Cost-effectiveness analysis from a military perspective. SETTING AND PATIENTS: A hypothetical cohort of 10,000 women who intended to complete at least 2 years of military service was studied. Analysis was based on data from 13,204 female trainees screened for chlamydial infection at Fort Jackson, SC. OUTCOMES: Program and training costs, cost of illness averted, and pelvic inflammatory disease (PID) prevented were determined for a 1-year follow-up period. Using sensitivity analysis, outcomes over 2 years were studied. RESULTS: At a 9.2% prevalence, no screening resulted in $220,900 in training and sequelae costs and 276 cases of PID. Screening by age produced the lowest cost $217,600, over a 1-year period and prevented 222 cases of PID for a cost-savings of $15 per case of PID prevented. Universal testing prevented an additional 11 cases of PID at a cost of $226,400, or costing $800 per additional case of PID prevented over age-targeted screening. Universal treatment prevented an additional 32 cases of PID and cost $221,100, saving $167 per additional cases of PID prevented over universal screening. Over a 2-year period, universal treatment provided the highest cost-savings and prevented the most disease. CONCLUSION: Screening by age provided a cost-savings to the Army over a 1-year period. Other organizations accessing large cohorts of young women could also benefit, even in the short term, from implementation of an age-based chlamydial screening program. Universal testing or universal treatment may be warranted in which long-term societal goals, such as maximum reduction of PID, are relevant.

A geographical information system technique for record-matching in a study of cancer deaths in welders.

Retrospective studies are frequently complicated by incomplete worker identifiers. We encountered this problem when evaluating the risk of cancer death in a welding cohort. We dealt with it by developing birth-date ranges for each welder with unknown birth dates and using geographical information system techniques in conjunction with last name, gender, and birth-date range to assign death certificates to welders on the basis of residential proximity to the worksite. Deaths for total malignant cancers and lung/tracheobronchial/pleural cancers among these welders were not significantly different from those in county, state, and US populations, using standardized mortality ratios. The ratios in our study subjects were consistent with ratios found in other published welder cohorts.

Respiratory diseases among U.S. military personnel: countering emerging threats.

Emerging respiratory disease agents, increased antibiotic resistance, and the loss of effective vaccines threaten to increase the incidence of respiratory disease in military personnel. We examine six respiratory pathogens (adenoviruses, influenza viruses, Streptococcus pneumoniae, Streptococcus pyogenes, Mycoplasma pneumoniae, and Bordetella pertussis) and review the impact of the diseases they cause, past efforts to control these diseases in U.S. military personnel, as well as current treatment and surveillance strategies, limitations in diagnostic testing, and vaccine needs.

Reemergence of adenovirus type 4 acute respiratory disease in military trainees: report of an outbreak during a lapse in vaccination.

From 23 April to 13 May 1995, an outbreak of acute respiratory disease (ARD) hospitalizations occurred in basic training soldiers at Fort Jackson, South Carolina. Weekly hospitalization rates for the most affected military unit reached 11.6%. Virus isolation and serologic studies from a sample of patients identified the agent as adenovirus type 4. Prior to starting vaccinations against adenovirus types 4 and 7 in 1971, these serotypes were the major causes of ARD in basic trainees. No outbreaks were reported when the vaccines were used. A logistical error temporarily interrupted vaccine production, and newly arriving trainees received no adenovirus vaccines from the summer of 1994 through late March 1995. This outbreak occurred in unvaccinated soldiers. The sole manufacturer has permanently stopped adenovirus vaccine production. All type 4 vaccine supplies are now depleted. This outbreak demonstrates continued susceptibility of military recruits to adenovirus type 4 and warns of future outbreaks.