A whirlpool associated outbreak of Pontiac fever at a hotel in Northern Sweden.

In April 1999, an outbreak of Pontiac fever occurred at a hotel in Northern Sweden. A retrospective cohort study to find the source and define the extent of the outbreak was carried out among 530 Swedish and Norwegian guests. Twenty-nine epidemiological cases (8% of 378 responders) aged 21-57 years were identified. Antibodies against Legionella micdadei were detected in 17 of 27 tested cases and 3 other symptomatic persons. Visiting the whirlpool area was identified as the sole risk factor (RR 86; 95% CI 21-352) and infected cases were confined to visitors to this area over three successive days. The attack rate was 71% (27/38) and 24 cases (83%) used the whirlpool. Environmental sampling was negative for Legionella sp. But epidemiological investigation strongly suggests that the whirlpool was the source of the outbreak. The possibility of serious legionella infections underlines the importance of strict maintenance practices to maintain hygiene of whirlpools.

Correlates of the spread of human papillomavirus infection.

Knowledge of the correlates of human papillomavirus (HPV) seropositivity is of interest for planning of preventive measures and for evaluation of possible confounding in epidemiological studies. The epidemiological determinants for seropositivity for oncogenic and benign HPV types were assessed using a serosurvey of 275 healthy Swedish women, stratified by age and lifetime number of sexual partners. Seroprevalences were compared with 17 behavioral variables obtained by interview and 3 laboratory-diagnosed microbiological exposures. In univariate analysis, history of gonorrhea and condylomatosis, human herpesvirus type 8 and herpes simplex virus 2 seropositivities, lifetime number of sexual partners, and current partner's lifetime number of sexual partners were associated with oncogenic HPV seropositivity. Noteworthy lack of correlations included smoking habits and oral contraceptive use. In multivariate analysis, only the number of lifetime sexual partners [odds ratio (OR), 8.7; 95% confidence interval (CI), 3.3-22.6] and seropositivity for benign HPV types remained significant (OR, 2.9; 95% CI, 1.6-5.3). Seropositivity for benign HPV was primarily associated with condyloma history (OR, 3.6; 95% CI, 1.2-10.8) and seropositivity for oncogenic HPV (OR, 2.9; 95% CI, 1.6-5.2). An association with sexual history lost significance in the multivariate model. In conclusion, lifetime number of sexual partners is the major determinant of acquisition of oncogenic HPV. By contrast, benign HPV infection associates more strongly with condyloma history than with sexual history per se.

Seropositivity to human herpesvirus 8 in relation to sexual history and risk of sexually transmitted infections among women.

The mode of transmission of human herpesvirus 8 (HHV8) was investigated in two seroepidemiological studies of Swedish women who completed a questionnaire about sexual behavior. Seropositivity for HHV8 antibodies, measured using an indirect immunofluorescence assay, was linked to a high number (>10) of sexual partners (P < 0.004). It also correlated strongly with a history of other sexually transmitted diseases (STD; P < 0.0001), in particular with a history of Chlamydia trachomatis infection and condyloma acuminata. There was appreciable HHV8 seropositivity already among virginal or monogamous women (9%). In summary, HHV8 transmission to women in Sweden may occur nonsexually. When sexual transmission occurs, it appears to be associated with high risk-taking sexual behavior.

Type specificity and significance of different isotypes of serum antibodies to human papillomavirus capsids.

Isotype-specific serum antibody responses against human papillomavirus (HPV) type 16 were evaluated by use of cross-sectional, prospective, and population-based seroepidemiologic studies. IgG1 and IgA were the most abundant isotypes. No sample contained IgG2, and <25 samples contained IgG3 or IgM. Total IgG, IgA, and IgG1 were HPV type specific and were associated with HPV-16 DNA (odds ratios [ORs], 5.4, 5.0, and 5.9, respectively; P<.001) but not with other HPV DNA (ORs, 1.2, 1.2, and 0.8, respectively; P value was not significant). Total IgG and IgG1 were strongly associated with number of lifetime sex partners (P<.001); IgA was only associated with number of recent sex partners and lifetime sex partners among younger women. Total IgG, IgG1, and IgA were associated with cervical intraepithelial neoplasia type III and also predicted risk of future cervical neoplasia. IgG and IgG1 appeared to mark lifetime cumulative exposure, whereas IgA may mark recent or ongoing infection.

Seroepidemiology of human papillomavirus type 73: a sexually transmitted low-risk virus.

Human papillomavirus type 73 (HPV 73) has been detected in some invasive cervical cancers and has been cloned from a squamous-cell carcinoma of the esophagus, but the epidemiology of this infection and its associated risk of cancer is unknown. We investigated the seroepidemiology of this virus using virus-like particles. The IgG response to HPV 73 appeared to be HPV type-specific, since a comparison of HPV 73 antibody levels before and after infection with HPV 6, 11, 16, 18 or 33 found no evidence of cross-induction of HPV 73 antibodies and since there was little correlation between the antibody levels to HPV 73 and the other 5 investigated HPV types. In both a cross-sectional serosurvey that included 274 women and a 7-year follow-up study that enrolled 98 women, HPV 73 seropositivity was found to be strongly dependent on the number of lifetime sexual partners [OR for > 4 vs. 0 to 1 partners: 6.0 (95%CI: 1.4-53.6) and 7.9 (95% CI: 2.8-28.3), respectively]. Finally, the risk for HPV 73 seropositive women to develop CIN was investigated in a prospective study nested in a cohort of 15,234 Swedish women. The population-based HPV 73 seroprevalence in Sweden was 14%. No excess risk for CIN was found (OR: 0.77). We conclude that HPV 73 is a mainly sexually transmitted, probably mostly transient, infection that does not confer any measurably increased risk for CIN development.

[Human parasites and amoeba: lower warm-water temperature is favourable to Legionella bacteria]. / Parasit hos människa och amöba: sänkt varmvattentemperatur gynnar legionellabakterierna.

Our knowledge of Legionella bacteria has increased since their discovery in 1977. Legionnaires' disease is an underestimated diagnosis in Sweden. Most cases are community acquired and probably due to the presence of legionella bacteria in the water distribution systems of buildings, though the precise source of infection often remains unknown. Although a number of putative virulence factors have been identified, to date few of them have been shown to be significant. The replication of legionella in human macrophages is similar to that in protozoa. Their interaction with protozoa might explain certain features of their ecology and virulence, and shed light on peculiarities in the transmission of infection. The urinary antigen assay has greatly facilitated the diagnosis of legionellosis, and methods based on the amplification of specific DNA sequences will probably become increasingly important, but isolation of the organism will still be justified. Traditional erythromycin therapy is likely to be replaced by treatment with new antimicrobials.

History, clinical findings, sexual behavior and hygiene habits in women with and without recurrent episodes of urinary symptoms.

BACKGROUND: To compare women with and without a history of recurrent symptoms suggestive of a urinary tract infection but a current negative urine culture regarding symptoms and signs of a genital infection, carriership of sexually transmitted agents and vaginal flora changes, sexual behavior and genital hygiene practice. SETTINGS: Contraceptive attendees at family planning and youth clinics. MATERIALS AND METHODS: Two hundred and seventeen women who reported recurrent symptoms of dysuria, frequent micturition, and urgency and had a negative bacterial urine culture were recruited as cases. Seven hundred and ten culture-negative women lacking such symptoms served as controls. A careful record was made including details about gynecological symptoms, sexual behavior and genital hygiene practice. Gynecological signs were noted at gynecological examination. Genital infections, including sexually transmitted diseases, were diagnosed. RESULTS: The mean age of the two groups studied was 26.2 and 25.8 years, respectively. Symptoms, such as dysmenorrhea, vaginal discharge, genital pruritus, abdominal pain and superficial dyspareunia were more frequent in the study group than among the controls. On examination, only erythema was observed more often. However, the cases more often had a history of genital herpes and vulvovaginal candidosis. They used tampons only for menstrual purposes, and soap for genital hygiene, but more often used low-pH solutions and took hot baths less frequently. The women with recurrent urinary symptoms more often masturbated and more often had experience of anal sex and sex during menstruation than the control group. CONCLUSIONS: Sexual behavior and genital hygiene habits may play an etiological role in the lives of women with recurrent episodes of urinary symptoms with a negative bacterial urine culture.

Risky behavior in women with history of casual travel sex.

OBJECTIVES: To define epidemiologic and psychosocial characteristics in women with a history of casual travel sex abroad. STUDY DESIGN: The participants consisted of 996 women attending for contraceptive advice, of whom 276 admitted that they had experience of casual travel sex. The remaining women served as a comparison group. In structured interviews, questions were asked about educational level, partnerships, reproductive history, contraceptive and drug use, smoking, and psychosocial factors such as wariness, success, and attractiveness. RESULTS: The women with experience of casual travel sex were more often single, had more often experienced broken relationships, were more often smokers, and used alcohol or cannabis at a higher-frequency. Their educational level was higher and a history of induced abortions was more common. CONCLUSIONS: The results of this study indicate that women with experience of casual travel sex not only take sexual risks, but take other risks that might impose danger to their health.

PIP: The aim of this study was to define epidemiologic and psychosocial characteristics of women with a history of casual travel sex abroad. The participants were 996 women seeking contraceptive advice, of whom 276 admitted that they had experienced casual travel sex. The remaining women served as a comparison group. In structured interviews, questions were asked about educational level, partnerships, reproductive history, contraceptive and drug use, smoking, and psychosocial factors such as wariness, success, and attractiveness. The women who had experienced casual travel sex were more often single, had more often experienced broken relationships, were more often smokers, and used alcohol or cannabis at a higher frequency. Their educational level was higher and a history of induced abortions was more common. The results of this study indicate that women with experience of casual travel sex not only take sexual risks but also take other risks that might represent a danger to their health.

Gynecological symptoms and vaginal wet smear findings in women with cervical human papillomavirus infection.

OBJECTIVES: To investigate the signs, symptoms and changes in the vaginal milieu that could be associated with cervical human papillomavirus infection (CHPI). STUDY DESIGN: Women (n = 972) attending for contraceptive advice were tested for human papillomavirus in cervical samples. Results of gynecological history, examination, and vaginal wet smear findings were compared between CHPI patients and negative women. RESULTS: Sixty-six (6.8%) of the women had a CHPI. Bacterial vaginosis was more common among those with, than without, CHPI, but the significance of this association was abolished after adjustment for age and for markers of sexual risk-taking. Vaginal discharge with a fishy odor, a positive amine test, and genital fissures showed significant correlations with CHPI, which persisted after adjustments. Symptoms of proctitis also correlated with CHPI, and remained significant after adjustment for anal sex. CONCLUSION: Bacterial vaginosis is associated with the presence of CHPI, possibly due to sexual behavioral factors. However, several other features, in particular the presence of amines, may be independently associated with CHPI.

Vaginal flora changes associated with Mycoplasma hominis.

OBJECTIVE: The aim of this study was to investigate any association between vaginal carriage of Mycoplasma hominis and genital signs and symptoms, other microbial findings, and some risk behavior factors in women with and without bacterial vaginosis. STUDY DESIGN: Women who had attended two family planning clinics and a youth clinic for contraceptive advice were divided depending on the result of vaginal culture for Mycoplasma hominis and the occurrence of bacterial vaginosis. The study population included 123 (12.3%) women who harbored Mycoplasma hominis. Those 873 (87.7%) with a negative culture for Mycoplasma hominis served as a comparison group. In the former group, 50 (40.7%) had bacterial vaginosis, which was also the case in 81 (9.3%) of the women in the comparison group. The groups were compared with regard to genital signs and symptoms, results of vaginal wet smear microscopy and other office tests, vaginal flora changes as detected by culture, and other means and detection of sexually transmitted diseases. Any history of sexually transmitted diseases and other genital infections, reproductive history, use of oral contraceptives, and smoking habits were registered. RESULTS: Women who harbored Mycoplasma hominis had significantly more often complained of a fishy odor, had a positive amine test, a vaginal pH > 4.7, and clue cells than did the comparison group; all these statements were true before and after bacterial vaginosis had been excluded. Vaginal discharge was not significantly more often complained of, and a pathologic discharge was not more often detected in the Mycoplasma hominis carriers. Ureaplasma urealyticum occurred in 75% of the Mycoplasma hominis-positive women and in 59% of the comparison group (p = 0.001). The leukocyte/epithelial cell ratio did not differ significantly from that of the Mycoplasma hominis culture-negative controls. CONCLUSION: The study suggests that Mycoplasma hominis is associated with a number of genital signs and symptoms even after exclusion of bacterial vaginosis.

Sexual risk behaviour in women carriers of Mycoplasma hominis.

OBJECTIVE: To study the sexual behaviour of women harbouring Mycoplasma hominis in the vagina. SETTING: Two family planning clinics and a youth clinic for contraceptive advice. METHODS: The vaginal flora of 996 women were investigated microbiologically, including culturing for M. hominis from the posterior vaginal fornix. Cultures and tests were also made to diagnose genital Chlamydia trachomatis infections, gonorrhoea, genital herpes, cervical human papillomavirus infection, trichomoniasis, genital warts and human immunodeficiency virus. The sexual behaviour of these women was investigated by structured in-depth personal interviews. RESULTS: Of the 996 women, 123 (12.3%) harboured M. hominis in the vagina. The remainder (87.7%), who had a negative M. hominis culture, served as a reference group. Those with M. hominis were significantly more likely to have had more than 10 partners during their lifetime, had a greater frequency of more than one sexual partner during the preceding month and the last six months, and reported more frequent experience of "casual sex', including casual "travel sex'. More of them also had experience of group sex and were more likely to have been sexually abused than the women in the reference group. Fewer women with M. hominis had a current steady partner and were less often cohabitors, but more had had sexual intercourse during the previous week than those in the reference group. There was an association between the occurrence of M. hominis and bacterial vaginosis and genital chlamydial infection. Adjustment in multifactorial regression analyses therefore changed the results only marginally. CONCLUSIONS: Women with M. hominis have almost the same sexual risk behaviour as women with classic sexually transmitted diseases.

Seropositivities to human papillomavirus types 16, 18, or 33 capsids and to Chlamydia trachomatis are markers of sexual behavior.

The association of seropositivity to human papillomavirus (HPV) capsids of types 11, 16, 18, or 33 with sexual behavior was investigated. Among 1002 women visiting family planning or youth clinics in Sweden, an age-matched subsample of 274 women stratified according to lifetime number of sex partners was analyzed. The proportion of HPV-16-seropositive subjects increased linearly at approximately 4% per partner (P < .001), from 4% among those with 1 lifetime partner to 35% among those with >5 lifetime partners. Also, HPV-33 and HPV-18 seroprevalences were linearly dependent on the number of partners (P < .001, increase with 4% per partner, and P = .008, increase with approximately 3% per partner, respectively), providing serologic confirmation that the important mode of transmission of HPV-16, -18, or -33 infection in women is sexual. HPV serology appears to be suitable as a marker of sexual behavior in populations.

Efficacy and safety of azithromycin versus lymecyline in the treatment of genital chlamydial infections in women.

To compare the clinical and microbiological efficacy of azithromycin in curing chlamydial infections in women with that of lymecycline, and with a view of the possibility of minimizing the problem of compliance by means of single-dose administration, 146 women with culture-positive Chlamydia trachomatis infections were randomly assigned to treatment with a 1 g bolus dose of azithromycin or a 10-day course of lymecycline 300 mg twice daily. Clinical and microbiological evaluations were performed and adverse effects monitored at check-ups after 15-35 and 40-65 days. Of the 146 patients enrolled in the study, 120 were evaluable. At the second check-up, C. trachomatis was found to have been eradicated in all patients in both treatment groups. Of the 51 patients who had clinical signs and symptoms of genital infection at enrolment, 96% (22/23) of those in the azithromycin group were considered cured (n = 18) or improved (n = 4), as compared with 100% (28/28) of those considered cured (n = 22) or improved (n = 6) in the lymecycline group. Adverse events related, or possibly related, to treatment were reported by 16 (21.6%) of the lymecycline group, but by only 6 (8.3%) of the azithromycin group. The 2 drugs were comparable with regard to microbiological and clinical efficacy in the treatment of genital chlamydial infection in women. The markedly lower rate of side-effects associated with azithromycin may be a feature conducive to patient compliance.

Sexually transmitted and other genital infections in women with cervical human papillomavirus infection.

OBJECTIVE: We investigated possible correlations between latent cervical human papillomavirus infection (CHPI) and other sexually transmitted diseases (STDs). METHODS: Of 972 randomly selected women attending 2 family planning clinics and a youth clinic who had agreed to participate in a study concerning STDs, 66 (6.8%) had latent CHPI. RESULTS: An association was found between latent CHPI on one hand and a history of genital chlamydial infection, gonorrhea, recurrent vaginal candidiasis, cervicitis, or pelvic inflammatory disease (PID) on the other, while no correlation between latent CHPI and coexistent STDs was found. No correlation of latent CHPI to either current or past genital warts was noted. In multifactorial analyses, which included the lifetime number of sexual partners and age at first intercourse, we found that all significant associations except a history of gonorrhea vanished. CONCLUSIONS: In this study population, screening for other current STDs in women with latent CHPI would be of limited value.

The epidemiology of Neisseria gonorrhoeae isolates in Greenland 1979-1990: the emergence, spread and disappearance of non-PPNG strains carrying the conjugative 38.9 kb plasmid.

BACKGROUND: In 1990, Greenland was one of the few areas in the world in which endemic occurrence of PPNG had not been reported. However, between 1982 and 1988 an increase in the prevalence of strains with chromosomally mediated resistance to penicillin had been noticed. The standard treatment regimen was changed early in 1983. OBJECTIVE: To determine the prevalence of the 38.9 kb plasmid in gonococcal strains isolated in Greenland 1979-1990. DESIGN: Retrospective (1979-1984) and prospective (1985-1990) studies of antimicrobial susceptibility and plasmid profile of consecutive N. gonorrhoeae isolates from patients attending the STD clinic in Nuuk, Greenland; selected strains from 1982-1984 were subjected to serotyping and auxotyping. RESULTS: Before 1982, N. gonorrhoeae strains harboring the 38.9 kb conjugative plasmid were rare; in 1982, a sudden increase in the prevalence of these strains was strongly associated with the emergence of streptomycin-resistant strains with high-level chromosomally mediated resistance to penicillin, 70% of which carried the 38.9 kb plasmid. Determination of antimicrobial susceptibility pattern, auxotype and serovar supported the assumption of an epidemic spread of a single clone. The predominance of this clone was transient, but the 38.9 kb plasmid spread to penicillin-susceptible as well as to other clones of penicillin-resistant strains. CONCLUSION: The emergence of the 38.9 kb plasmid in 1982 was linked to a single clone of strains, but the subsequent spread of the plasmid was independent of the presence of other plasmids, and its disappearance was not associated with a change in standard treatment regimen.

Antibiotic susceptibility, serovars and auxotypes of gonococcal isolates in Stockholm. Relation to geographical origin of the infection.

The antibiotic susceptibility, serovars and auxotypes were investigated in gonococcal strains isolated from all patients with gonorrhoea during one year in Stockholm, Sweden. The results were correlated to geographical origin of the infection. A total of 394 gonococcal strains were isolated from 392 patients, 135 (34%) women and 257 (66%) men. Beta-lactamase-producing gonococcal strains (PPNG) were isolated from 5% of the women and 16% of the men. Men had acquired their infection abroad more often than women (54% vs 33%) (P < 0.001). The majority (81%) of the PPNG infections were imported. Some serovars and auxotypes were more common among imported strains than among indigenous ones. All strains were sensitive to spectinomycin and 2 strains had decreased susceptibility to norfloxacin and ciprofloxacin. Decreased susceptibility to benzylpenicillin, ampicillin, doxycycline and cefuroxime was related to the geographical origin of the strains with strains imported from regions other than Europe being the most resistant.

Antibiotic susceptibility of upper respiratory tract pathogens in Sweden: a seven year follow-up study including loracarbef. Swedish Respiratory Tract Study Group.

The antibiotic susceptibility of Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pyogenes and Streptococcus pneumoniae was investigated in five different geographical areas of Sweden in 1990 and compared with results from similar investigations performed in 1983 and 1986. Tests on 100 isolates per species and laboratory were performed by the disk diffusion method, and 10% of the strains plus all resistant ones were sent to the central laboratory for determination of MICs of ampicillin, phenoxymethylpenicillin, cefaclor, loracarbef, erythromycin, tetracycline and trimethoprim/sulfamethoxazole. Beta-lactamase production was found in 7% of H. influenzae and 71% of M. catarrhalis, and reduced susceptibility to penicillin in 3% of S. pneumoniae. Low frequencies (1-3%) of tetracycline resistance were found in H. influenzae and in the 2 streptococcal species, in which also less than 1% of the strains were resistant to erythromycin. Resistance to trimethoprim/sulfamethoxazole occurred in 7% (range 3-14%) of H. influenzae and in 3% of S. pneumoniae. Cefaclor was active against all streptococci except against S. pneumoniae with reduced susceptibility to penicillin. It was active against beta-lactamase negative strains of M. catarrhalis but had, according to the SIR-system, intermediate activity against H. influenzae. Loracarbef was twice as active as cefaclor against H. influenzae but equally active against the 3 other species tested.

Diagnosis of pneumonia by cultures, bacterial and viral antigen detection tests, and serology with special reference to antibodies against pneumococcal antigens.

In a prospective study of the etiology of pneumonia 196 adult patients were included. One of the following criteria was required for diagnosis of pneumococcal pneumonia: isolation of pneumococci from blood; isolation from transtracheal aspirate; isolation from sputum or nasopharynx or detection of capsular antigen in sputum in combination with a significant increase in antibodies against at least one pneumococcal antigen (type-specific capsular polysaccharide, C-polysaccharide, pneumolysin); or increase in antibodies against two pneumococcal antigens. Pneumococcal pneumonia was diagnosed in 63 patients (32%). Other diagnoses were nonencapsulated Haemophilus influenzae isolated from transtracheal aspirates, 9; Mycoplasma pneumoniae diagnosed by serology, 17; Chlamydia psittaci, 6; and viral infections, 42. Twenty-two patients (11%) had evidence of infection with more than one agent. The pathogen could not be determined in 70 (36%). Many patients were given antibiotics before admittance to the study, and in some cases a convalescent serum sample was not available.