An evaluation of the IFA-GC procedure in a low risk population

An automated indirect fluorescent antibody (IFA) test for gonococcal antibody was evaluated in 600 low risk females; 392 were prenatal patients from public and private clinics and 208 were apparently healthy females state employees in a multiphasic screening program. Clinical histories, physical examinations, and cervical cultures were obtained on all patients. The results of the cultures and serologic test were compared. Although the number of culture positive patients in the study was low, the lack of sensitivity of the IFA test in detecting gonococcal infection in these patients was disturbing. This observation and the number of apparent false positive IFA tests lead us to conclude that the automated IFA test for detection of gonorrhea shows promise, but we could not consider adopting the test in its present stage of development.     

Prevalence and epidemiologic correlates of human T cell lymphotropic virus infection among intravenous drug users

Intravenous drug users (IVDUs) in Seattle (n = 213) were studied to identify the prevalence and predominant types of and risk factors for human T cell lymphotropic virus (HTLV) infection. Detailed questionnaires, serologic screening, and polymerase chain reaction analysis (for a subset) were used. Evidence of HTLV infection was found in 16.5%, of which 89% were HTLV-II. HTLV infection was significantly associated with nonwhite race, older age, more years of intravenous drug use, prior use of heroin, history of gonorrhea, history of any sexually transmitted disease, hepatitis B virus infection, and antibody to herpes simplex virus type 2 (HSV-2). By stepwise logistic regression analysis, associations persisted with race, age, hepatitis B markers, and HSV-2. Thus, the strong association of HTLV with hepatitis B, a marker for injection behavior, and the independent association with HSV-2 infection, a sexually transmitted pathogen, suggest similarities in the epidemiology of HTLV and human immunodeficiency virus infections in IVDUs.     

Screening women for gonorrhea: demographic screening criteria for general clinical use

OBJECTIVES: The purpose of this analysis was to derive potential gonorrhea screening criteria for women. METHODS: Data corresponding to 44,366 gonorrhea cultures from women 15 through 44 years of age in Columbus, Ohio, were analyzed. RESULTS: Characteristics that were associated with gonococcal infection and were suitable for screening decisions included patient's age and marital status and previous prevalence of gonorrhea at provider site. Probabilities of infection ranged from .001 for married women 25 through 44 years of age at low-prevalence provider sites to .078 for unmarried women 15 through 19 years of age at high-prevalence sites. CONCLUSIONS: Patient's age and marital status and prevalence of gonorrhea at provider site can be used as indicators to ensure testing of high-prevalence groups.     

Trial production of an admittance plethysmograph]

Direct urethral and cervical smears for gonorrhea in women are useful because of their high specificity. Male rectal smears are less efficacious. Direct tests for candidiasis and trichomoniasis are also specific, but less sensitive than generally thought. Most tests exhibit only moderate month-to-month variability. No association between infection with trichomonads and gonococci was demonstrated. The gonococcal tests all perform best under conditions of high prevalence, such as those that obtain in venereal disease clinics in the United States.     

Ultrastructural analysis of primary human urethral epithelial cell cultures infected with Neisseria gonorrhoeae

In men with gonococcal urethritis, the urethral epithelial cell is a site of infection. To study the pathogenesis of gonorrhea in this cell type, we have developed a method to culture primary human urethral epithelial cells obtained at the time of urologic surgery. Fluorescent analysis demonstrated that 100% of the cells stained for keratin. Microscopic analyses indicated that these epithelial cells arrayed in a pattern similar to that seen in urethral epithelium. Using immunoelectron and confocal microscopy, we compared the infection process seen in primary cells with events occurring during natural infection of the same cell type in men with gonococcal urethritis. Immunoelectron microscopy studies of cells infected with Neisseria gonorrhoeae 1291 Opa+ P+ showed adherence of organisms to the epithelial cell membrane, pedestal formation with evidence of intimate association between the gonococcal and the epithelial cell membranes, and intracellular gonococci present in vacuoles. Confocal studies of primary urethral epithelial cells showed actin polymerization upon infection. Polyclonal antibodies to the asialoglycoprotein receptor (ASGP-R) demonstrated the presence of this receptor on infected cells in the primary urethral cell culture. In situ hybridization using a fluorescent-labeled probe specific to the ASGP-R mRNA demonstrated this message in uninfected and infected cells. These features were identical to those seen in urethral epithelial cells in exudates from males with gonorrhea. Infection of primary urethral cells in culture mimics events seen in natural infection and will allow detailed molecular analysis of gonococcal pathogenesis in a human epithelial cell which is commonly infected.     

Radiofrequency ablation of a fascicular tachycardia after orthotopic cardiac transplantation

Serology is a critical component in the diagnosis of amebic liver abscess. However, in areas endemic for amebiasis there is a high background level of seropositivity for amebiasis (owing to previous infection with Entamoeba histolytica), which may complicate the interpretation of a positive serologic test result. Recently, we reported that serologic tests based on recombinant E. histolytica antigens might offer improved diagnosis of current invasive amebiasis because they apparently differentiated active infection from past exposure to the parasite. To confirm this finding, we have performed a longitudinal study on 20 patients with amebic liver abscess by examining their seroreactivity over time with recombinant versions of two major E. histolytica proteins, the serine rich E. histolytica protein (SREHP), and the 170-kD subunit of the galactose-specific adhesin. We found that more than 50% of the patients examined had become seronegative by one or both recombinant tests within 180 days of their diagnosis of amebic liver abscess. In the case of the recombinant SREHP-based tests, 12 patients had become seronegative 90 days after presentation. In contrast, all patients remained seropositive by a standard conventional test, an indirect hemagglutination test, at more than six months after presentation. Our study shows that patients lose seroreactivity with the recombinant SREHP or 170-kD antigen-based tests more rapidly than with a conventional serologic test; this may make them useful for the serologic diagnosis of amebiasis in endemic areas.     

Calcium and endoplasmic reticulum dynamics during oocyte maturation and fertilization in the marine worm Cerebratulus lacteus

Disseminated gonococcal infection is the most common systemic complication of acute gonorrhea and occurs in 0.5% to 3.0% of patients with untreated mucosal infection. It is also the most common cause of septic arthritis in patients less than 30 years of age. Fortunately, the incidence of gonorrhea is decreasing dramatically in the United States and Western Europe, although it is still high in developing countries. Increasing resistance to antibiotics requires continuous surveillance of antimicrobial susceptibilities to determine the efficacy of current therapeutic measures.     

Pharmacokinetics of the transdermal reservoir membrane system delivering beta-estradiol: in vitro/in vivo-correlation

We report here the evaluation of the potential of a serologic test to determine the endemicity of onchocercal infection in hyper, meso, and hypoendemic communities by the detection of antibodies to a cocktail of recombinant antigens. Parasitologic parameters of infection prevalence and intensity were compared with serologic results. Infection prevalence by serology was consistently but not significantly higher than that defined by parasitology. Differences between the communities defined by microfilarial load (CMFL) and a measurement of Onchocerca volvulus-specific antibody levels (serologic index [SI]) were similar. When stratified by age, differences were more significant in the younger age groups. If a sentinel population of 5-15-year-old individuals was used to compare communities, all could be equally ranked by serologic and parasitologic parameters. The SI of the sentinel population gave a better distinction between each community than the SI of the whole and would be sufficiently sensitive to measure the changes in endemicity that would be required for onchocerciasis control programs.     

Controversies in the laboratory diagnosis of community-acquired urinary tract infection

Urine samples constitute the largest single category of specimens examined in most medical microbiology laboratories. The everyday nature and apparent simplicity of urinary tract infection belies the intense debate and controversy regarding the optimal methods of collection, transport and processing of urine specimens and reporting of results. There is considerable variation in the interpretation of quantitative culture results between laboratories and the etiology of abacterial cystitis remains unclear. Microscopy to detect pyuria provides information on an important indicator of inflammation and it has been proposed that detection of urinary antibody may provide similar information. Neither of these indices of host response is suitable for use in a screening test for urinary infection however, although they may usefully contribute to the interpretation of significance of culture results. The development of screening tests and automated systems continues, but at present microscopy and culture remain the most important techniques for laboratory diagnosis. However, these techniques have so far failed to provide an etiological diagnosis for abacterial cystitis and this remains a major area for research.     

Long-term peritoneal dialysis before transplantation and intra-abdominal infection after simultaneous pancreas-kidney transplantations

OBJECTIVE: To examine the attitudes and knowledge of health care professionals regarding human immunodeficiency virus (HIV) infection in countries with a varying prevalence of HIV infection to assist in the development of acquired immunodeficiency syndrome (AIDS) educational programs. DESIGN: Anonymous questionnaire with four sections: demographics, attitudes, knowledge, and an open-ended question investigating feelings about the potential impact that HIV infection may have on respondents' practices. PARTICIPANTS: Final-year medical students, house staff, and attending physicians at teaching hospitals in India, Thailand, Canada, and the United States. RESULTS: From January to October 1992, 819 health care professionals completed the questionnaire: 340 from India, 196 from Canada, 155 from the United States, and 128 from Thailand. The percentage of respondents who had previous contact with patients with HIV/AIDS varied from 30% to 98%; it was lowest in India, followed by Thailand and then Canada, and highest in the United States. Percentages of respondents uncomfortable performing a physical examination on a patient with HIV/AIDS were 24%, 25%, 9%, and 4%, respectively. Mean HIV/AIDS knowledge scores were 83%, 84%, 92%, and 93%, respectively. Most respondents correctly identified modes of transmission of HIV infection. Only 67% of Indian health care professionals understood the concept of a false-negative screening serologic test, compared with 98% of Canadian health care professionals. In Canada and the United States, only 78% and 76%, respectively, understood the concept of a false-positive screening serologic test. Awareness of an asymptomatic stage of HIV infection ranged from 32% in India to 74% in Canada. Despite their concerns of becoming infected, health care professionals in countries with a lower prevalence of HIV infection reported a strong ethical duty to care for these patients. CONCLUSIONS: Level of comfort in caring for HIV-infected patients and HIV/AIDS knowledge scores varied directly with the amount of previous contact with these patients. Disturbing numbers of health care professionals from all four countries did not understand the potential problems of the enzyme-linked immunosorbent assay serologic test and a significant percentage were unaware of the asymptomatic stage of HIV infection. There is a universal need for increased education of health care professionals about HIV infection and AIDS.     

Priorities for HIV testing in developing countries?

The specificity and sensitivity of human immunodeficiency virus (HIV) antibody tests have increased and their use has expanded in developed and developing countries since 1985. Lately, more expensive rapid (US $3-12/test) and cheaper HIV tests have been proposed. HIV testing by the inexpensive enzyme-linked immunosorbent assays (ELISAs) is often infeasible in developing countries because of the lack of equipment. In 1990, in Kinshasa, Zaire, only about 50% of blood donors were screened for HIV. Counseling before and after testing at centers sponsored by non-governmental organizations is limited in developing countries. HIV testing can lead to discrimination: people have been put in quarantine because they were found to be HIV positive. In regions of high prevalence, high priority testing for blood transfusion is cost beneficial. A positive HIV test would justify the start of treatment for toxoplasmosis in a patient with a focal neurological deficit. In a region of high HIV prevalence, a patient with chronic diarrhea would benefit more from an HIV test than from gastroenterological tests. The absence of facilities for CD4 cell counting makes it impossible to advise symptom-free HIV infected subjects. Prophylactic isoniazid may decrease the incidence of Mycobacterium tuberculosis infection among HIV-infected people but the potential for non-compliance with treatment and the risk that drug resistance will develop exist. Confidential HIV testing plus counseling and condom promotion decreased the incidence of HIV infection and gonorrhea among women living in Kigali, Rwanda. There has been successful counseling of discordant couples with HIV infection in Kigali, Rwanda, and Kinshasa, Zaire. HIV testing in the most cost-beneficial way should be done for both members of a steady couple at the same time. HIV tests should be more available in developing countries, and national guidelines for HIV testing should be set.     

Human immunodeficiency virus seropositivity in adolescents with syphilis

OBJECTIVE: The purpose of this study was to assess the relationship between syphilis and human immunodeficiency virus (HIV) infection among inner-city, minority group adolescents. METHODS: From August 1989 through June 1990, serum from all positive serologic tests for syphilis, obtained from patients attending a comprehensive adolescent health center in an acquired immunodeficiency syndrome epicenter and its two school-based clinics, were frozen without patient identifiers and were subsequently screened for HIV by enzyme-linked immunosorbent assay with confirmatory Western blot for positives. In addition, a retrospective chart review was performed for all patients with a positive serologic test for syphilis during the study period. RESULTS: Of the 59 specimens with a positive syphilis serologic test, 9 (15.3%) were HIV seropositive. Of the patients with syphilis, 57.4% were black and 42.6% were Hispanic; 16.4% were male (mean age 18.1) and 83.6% were female (mean age 17.8). Only 1 subject (female) was an injection drug user; 4 of the male subjects self-identified as having had sex with other males. Of the subjects, 27.8% had primary, 19.7% had secondary, and 52.5% had latent syphilis at the time of diagnosis. A prior or concurrent sexually transmitted disease was present in 90% of the males and 80% of the females; gonorrhea was the most prevalent sexually transmitted disease in the males (89%) and chlamydia was most prevalent in the females (35%). A history of chancroid and/or herpes was present in 16.4% of the subjects. CONCLUSIONS: It is concluded that the diagnosis of syphilis in an adolescent is a risk factor for HIV infection. All sexually active adolescents should be routinely screened for syphilis, regardless of sexual practices. Those with syphilis should be specifically counseled about their increased risk for HIV infection and the importance of consistent condom use, and they should be referred for formal HIV pretest counseling.     

Prevalence, incidence, and risks for HIV-1 infection in female sex workers in Miami, Florida

Annual cross-sectional prevalence, incidence of new infection, and risks for human immunodeficiency virus type 1 (HIV-1) infection were studied in 607 women convicted of prostitution between October 1987 and December 1990 and tested for HIV under court order. Cross-sectional prevalence was stable for 4 years (23-24% positivity in 1987-1991, p = 0.6). However, the incidence of new infections (rate of seroconversion) in 264 women tested more than once increased significantly each year from 12 per 100 person-years in 1987-1988 to 19 per 100 person-years in 1991 (p < 0.03). Seroconverters were more likely to be young black women with a prior history of syphilis or gonorrhea. A new episode of syphilis or rectal gonorrhea during the follow-up period predicted HIV seroconversion in a survival analysis model. Female sex workers are at great risk of acquiring HIV infection. Although HIV prevalence in cross-sectional samples was stable, incidence was increasing. Interpretation of prevalence trends from convenience samples, such as screening programs, may be difficult because changes in incidence may not be detected.     

Morphological characterization of small cells resulting from nutrient starvation of a psychrophilic marine vibrio

In a study of 662 sera from a hydatidosis endemic area, the indirect hemagglutination test based on a minimal nonspecificity criterion of positivity and the latex agglutination (LA) test were found to be suitable screening techniques for the detection of sera positive to the arc 5, diagnostic of hydatid infection. The lower nonspecificity of the LA test, its greater simplicity and its excellent correlation with the immunoelectrophoresis test suggest that it is the choice screening technique for use in field surveys or seroepidemiologic studies of hydatid disease. The advantages and limitations of this serologic approach for the detection of human hydatid cyst carriers in field studies are discussed.     

Evaluation of diagnostic procedures to detect Mycoplasma synoviae in commercial multiplier-breeder farms and commercial hatcheries in Florida

Sera from 5325 chickens representing 71 commercial poultry flocks were tested for Mycoplasma synoviae (MS) using standard National Poultry Improvement Program (NPIP) testing guidelines. Based on the NPIP guidelines, only sera (N = 195) from flocks that test positive by specific plate agglutination (SPA) were submitted for additional confirmatory tests. Flocks from three multihouse farms were identified as seropositive for MS and confirmed by culture and polymerase chain reaction (PCR). Serum samples (N = 195) from these seropositive flocks were compared by SPA, enzyme-linked immunoassay (ELISA), and hemagglutination-inhibition (HI). Of the 195 sera tested for MS from these flocks, 145 (74%) sera were positive by SPA. Of the 145 SPA-positive sera, the HI test was positive for 127 samples (90.2%), whereas the ELISA was positive for 141 samples (98.6%). This difference between the two tests was significant (P = 0.0006). Significant differences (P = 0.0002) in titer were obtained from paired serum samples that were submitted to three different laboratories for HI analysis. Both the SPA and HI tests failed to detect early infection in newly introduced flocks following depopulation of MS-positive facilities. Both ELISA and PCR detected new infections on these farms. In the MS outbreak described in this study, SPA was not adequate as the sole screening test and HI was not adequate for confirmation of flock infection status. Continued reliance on the same or a similar type of testing could result in missed infections. Confirmation of infection by PCR was preferable to HI and also may be used in place of culture. The findings of this study suggest that ELISA should be considered as a serologic screen in lieu of SPA, screening with SPA may miss MS-infected flocks, and PCR should be considered as a confirmatory test.     

Taking the low (stretch) road

Helicobacter pylori infection can be detected by several invasive tests based on gastroscopy and by noninvasive methods such as serologic assays. Noninvasive tests can be used not only in addition to invasive tests but also by themselves to screen for H. pylori infection in patients who are not in urgent need of endoscopy. Lately, rapid qualitative serologic tests have been developed. In the present study, the accuracy of a novel rapid whole-blood test, Pyloriset Screen, detecting immunoglobulin G (IgG) and IgA antibodies against H. pylori was evaluated. A total of 207 consecutive adult outpatients referred for upper endoscopy were enrolled. Gastric biopsy specimens were taken from the antrum and corpus for histologic examination and rapid urease testing. Cultures were available for 113 patients. Serum samples collected from all patients were tested for H. pylori antibodies by two enzyme immunoassays (EIAs) (Pyloriset EIA and an in-house EIA), a rapid latex agglutination test (Pyloriset Dry), and Pyloriset Screen. Patients were considered H. pylori positive if helicobacters were seen on histologic examination (77 patients) or, if in combination with histologically verified (although helicobacter-negative) gastritis, their IgG antibody titers were elevated in the two EIAs (five patients). The Pyloriset Screen test had a sensitivity of 95%, a specificity of 94%, a positive predictive value of 91%, and a negative predictive value of 97%. Among 63 patients under the age of 45 years, the Pyloriset Screen test did not miss a single H. pylori diagnosis, and only 1 patient had a false-positive result. Pyloriset Screen could be used reliably to screen for H. pylori infection.     

Cutaneous leishmaniasis associated with jungle training

In November 1977, 627 soldiers belonging primarily to the First Battalion, 82nd Airborne Division, stationed at Fort Bragg, were sent to the Canal Zone, Panama, for jungle warfare training. A medical surveillance program incorporating pre- and post-evaluations over a 6-month period with dermatologic examinations, questionnaires, and serologic tests was established. Ten cases of cutaneous leishmaniasis (1.6/100 men) were diagnosed by positive Leishmania culture. The demonstrated lack of sensitivity and specificity of the indirect fluorescent antibody test and the direct agglutination test render these serological methods useless as diagnostic screening methods in the early stages of this disease.     

Asymptomatic sexually transmitted disease prevalence in four military populations: application of DNA amplification assays for Chlamydia and gonorrhea screening

The prevalence of asymptomatic chlamydial and gonococcal infections in male and female military populations was determined using urine-based ligase chain reaction DNA amplification assays (DAAs). Cross-sectional surveys in four military settings revealed an overall prevalence of asymptomatic chlamydial infection of 4.2% (56/1338). This included 3.4% (21/618) of Western Pacific shipboard US Marine Corps enlisted men; 5.2% (21/406) of male marines shore-based in Okinawa, Japan; 2.7% (5/183) of female enlisted US Navy subtender personnel in dry dock; and 6.9% (9/131) of shore-based female naval personnel in San Diego. No gonococcal infections were detected. All subjects were treated within 2 weeks of screening; none of them had progressed to symptomatic disease. General population-based screening for asymptomatic sexually transmitted diseases, and in particular chlamydial infection, can be successfully implemented using urine-based DAA tests. Benefits are maximized in a population in which compliance for follow-up therapy is high.     

Anthropometric, strength, endurance and flexibility characteristics of elite and recreational climbers

Chlamydia trachomatis is a primary cause of acute or silent salpingitis leading to infertility and ectopic pregnancy. The C. trachomatis epidemic, undiscovered in most cases, spreads, mostly in adolescents, during the years following the onset of sexual activity. As opposed to gonococcal infection which has greatly decreased, C. trachomatis cervical and urethral infection is common in young occidentals. More then 30 different studies covering 200-12,000 subjects screened in family planning centers, college women and men, students and military recruits in different parts of the USA, in Scandinavian countries and France, indicate a prevalence of 5-20% (mean 10%) in apparently healthy young females < 25 years and 5-10% in males. Female prevalence is strongly related to age, being highest (15-20%) in women < 20 years old. Several cost-benefit analyses show that the total cost of the general screening in young populations, which can easily be carried out for women in family planning centers, could save twice the cost of treatment for pelvic inflammatory disease caused by C. trachomatis and six times the total cost of C. trachomatis epidemics if late sequelae are taken into account (tubal infertility treatment, ectopic pregnancy). There is a debate among authors concerning the relative merits of total screening versus selective screening in family planning centers, the most common opinion being to do a total screening of women < 20 years old and selective screening of women 20-30 years of age with at least one risk factor, the most common risk factors being more than one partner in a year, purulent, cervical discharge, failure to use condoms and use of a contraceptive pill. Although the data clearly show that C. trachomatis screening is cost-effective, conducting of the diagnostic laboratory tests used in such screening programs should be carefully evaluated relative to cost, feasibility, specificity and sensitivity and should be adapted to the presumed prevalence in screened populations.     

Maternal and congenital syphilis

Testing for syphilis during pregnancy reveals a positive serologic status in 0.02% of cases. However, a 66% rate of stillbirths is noted in women who are infected and who have not benefited from any treatment. Routine screening is at present performed during the early stages of pregnancy but a second serologic test during the third trimester is useful in the diagnosis of a late infection especially in drug users or HIV (human immunodeficiency virus) positive patients. Congenital syphilis is diagnosed in utero when a positive maternal serologic status is associated with ultrasound images showing fetal abnormalities; these include hepatosplenomegaly, hyperechogenic bowel, signs of bowel obstruction or fetal hydrops. Maternal syphilis is treated by delayed action penicillin and is indicated even for patients allergic to the antibiotic which in this particular case is delivered after desensitization. First line therapy by intravenous penicillin is indicated when confronted with the following high risk factors of congenital syphilis: an elevated titre of VDRL (venereal disease research laboratory) at the time of diagnosis or delivery, unknown date of the precise onset of the infection, the appearance of a rash or of a chancre during pregnancy, ultrasound fetal abnormalities or late therapy during the third trimester. Treatment of the new-born child will depend on the results of clinical, serologic and X-ray evaluation. Long term follow-up for at least a year is mandatory.