Burden of Chlamydia trachomatis in India: a systematic literature review

Chlamydia trachomatis (hereafter CT) is Gram-negative, obligate intracellular pathogen. It causes the world's most common non-viral sexually transmitted disease. India is home to the world's greatest burden of infectious diseases, yet information on prevalence rates of CT is scarce. This article systematically reviews the literature for the prevalence rates and testing methods in India. A total of 27 studies were included. Four main patients groups (symptomatic women, infertile women, pregnant women and asymptomatic population groups) could be identified with varying rates of CT (0.1%-32% using PCR, 2.4%-75% using ELISA serology). Most of the studies originated from urban settings, 11 of them from New Delhi. In-house PCR was the most common diagnostic technique used generating the following ranges in prevalence for the four group studies: symptomatic women 10%-50%, pregnant women 0.1%-2.5% and asymptomatic populations 0.9%-24.5%. The rates among infertile women were 9%-68% based on serology results. The prevalence rates featured in this paper are in line with other locations across the Indian subcontinent. This review highlights the extreme heterogeneity in the limited studies available in India on CT and the need for standardized guidelines for diagnosis and management of CT in India. The availability of resources should be considered in the formulation of recommendations.

Performance of the multitarget Mikrogen Chlamydia trachomatis IgG ELISA in the prediction of tubal factor infertility (TFI) in subfertile women: comparison with the Medac MOMP IgG ELISA plus

There is a need for more accurate Chlamydia trachomatis (CT) IgG antibody tests for tubal factor infertility (TFI) diagnostics. We evaluated the predictive value for TFI of Medac ELISA plus (MOMP) and multitarget Mikrogen ELISA (MOMP-CPAF-TARP). Based on Medac ELISA plus results, 183 subfertile women underwent either hysterosalpingography or laparoscopy to diagnose TFI. TFI was defined as extensive adhesions and/or distal occlusion of at least one tube. Women not fulfilling the definition of TFI served as controls. Serum was subsequently tested with Mikrogen ELISA and results were compared. 48 patients had TFI, 135 were controls. Mikrogen ELISA tested 125 patients positive/borderline of which 32% had TFI. Medac ELISA plus tested 77 patients positive/borderline of which 29.9% had TFI. Mikrogen tested 40 out of 48 TFI patients positive/borderline, Medac 23 out of 48. Kappa value was 0.34. PPV of Mikrogen ELISA and Medac ELISA plus were respectively 32% (95% CI 26%-39%) and 30% (95% CI 24%-37%), and NPV 86% (95% CI 81%-91%) and 76% (95% CI 70%-82%). Both tests were comparable in the prediction of TFI. However, Mikrogen ELISA had a higher NPV and might be more reliable in identifying patients without TFI. Kappa-value showed limited concordance between both tests.

Specific polymorphisms in the vitamin D metabolism pathway are not associated with susceptibility to Chlamydia trachomatis infection in humans

Chlamydia trachomatis is the most common sexually transmitted bacterium worldwide. Its often asymptomatic course of infection increases chances of transmission, and increases risk of late complications. Genetic variations in the host immune system are known to impact the course of infections. Recent studies have shown a positive impact of vitamin D on the regulation of the immune system. This study assesses the impact of eight polymorphisms in five genes [VDR (rs1544410 G > A, rs2228570 C > T), CYP27B1 (rs10877012 G > T), DHCR7 (rs7944926 G > A, rs3829251 G > A), GC (rs3755967) and CYP2R1 (rs10741657 G > A, rs2060793 G > A)] on susceptibility to Chlamydia infections in humans. These polymorphisms could influence protein expression or function, and thus influence the immune system. Samples of women visiting the STD outpatient clinic in South Limburg were genotyped using the Roche Lightcycler 480. In this study, we did not observe statistically significant differences between the genotype distributions of these polymorphisms in women with or without a Chlamydia infection. This suggests that VDR, CYP27B1, DHCR7, GC and CYP2R1 do not affect the susceptibility to Chlamydia infections. However, due to its pleiotropic nature in the immune system a role for the vitamin D pathway may not be excluded from the whole clinical course of Chlamydia infections (e.g. late complications), and further research is required.

Potential protective effect of a G>A SNP in the 3'UTR of HLA-A for Chlamydia trachomatis symptomatology and severity of infection

The interindividual differences in response to Chlamydia trachomatis (CT) infections are for an important part based on the differences in our host genetic make-up. In the past, several genes and pathways have been identified and linked to protection against or risk for CT infection (i.e. susceptibility), and/or the severity of infection, with a major emphasis on the development of tubal pathology, one of the main causes of female infertility. In the current study, we analyzed in Dutch Caucasian women whether the carriage of HLA-A G>A SNP (rs1655900) was related to the susceptibility of CT infection in a STD cohort (n = 329) and to the severity of infection in a subfertility cohort (n = 482). We also investigated if this A-allele was linked to increase in severity of symptoms, from mild symptoms (lower genital infection) to lower abdominal pain (upper genital tract infection) to the most severe late complication of tubal pathology, including double-sided tubal pathology. We showed that the carriage of HLA-A SNP rs1655900 studied is not associated with the susceptibility to CT infection based on the data from the STD cohort, but might be protective to the development of late complications (p = 0.0349), especially tubal pathology could be relevant.

Association of sexually transmitted infections, Candida species, gram-positive flora and perianal flora with bacterial vaginosis

Bacterial vaginosis (BV) is characterised by depletion of the normal Lactobacillus spp. and overgrowth of commensal anaerobic bacteria. We investigated the composition of vaginal microbiota and their association with BV in women of reproductive age. Vaginal samples from 1197 women were analysed, whereby n=451 patients had normal flora and n=614 were diagnosed with BV, the remaining patients were diagnosed with having either intermediate flora (n=42) or dysbacteriosis (n=90). The reported results show that pathogens are associated with BV. This knowledge will further expand our understanding of events leading to BV, which may lead to more effective prevention and treatment strategies.

A misleading false-negative result using Neisseria gonorrhoeae opa MGB multiplex PCR assay in patient's rectal sample due to partial mutations of the opa gene

A 53-year-old homosexual man presented at his general practitioner (GP) practice with a suspicion of sexually transmitted infection. Initial NAAT screening was performed for Chlamydia trachomatis and Neisseria gonorrhoeae. The patient was positive for Neisseria gonorrhoeae both for his urine and rectal sample. The subsequent confirmation test for Neisseria gonorrhoeae by a second laboratory was only confirmed for the urine sample and the rectal sample was negative. We report a case of a potential false-negative diagnosis of Neisseria gonorrhoeae due to mutations of DNA sequence in the probe region of opa-MGB assay of the rectal sample. The patient did not suffer any discomfort as diagnosis of Neisseria gonorrhoeae in his urine sample had already led to treatment by prescribing the patient with Ceftriaxone 500 mg IV dissolved in 1 ml lidocaine 2% and 4 mL saline. The patient also received a prescription for Azithromycin (2x500 mg).

High throughput multiplex-PCR for direct detection and diagnosis of dermatophyte species, Candida albicans and Candida parapsilosis in clinical specimen

We have developed and validated a multiplex-PCR method for detection of dermatophyte spp., Candida albicans and parapsilosis for routine diagnostics. Our m-PCR showed excellent concordance with culture results in 475 clinical samples. Through the rapid diagnosis by our m-PCR, clinicians are able to initiate adequate antimycotic therapy much earlier.

NOD1 in contrast to NOD2 functional polymorphism influence Chlamydia trachomatis infection and the risk of tubal factor infertility

Intracellular pattern-recognition receptors NOD1 and NOD2 are capable of sensing common structural units of bacterial walls. Recognition triggers specific immune signalling pathways and leads to pro-inflammatory cytokine upregulation and adequate immune response. We investigated whether two functional polymorphisms in NOD1 and NOD2 exert an effect on susceptibility to (STD patients) and severity of (female patients visiting the fertility clinic) Chlamydia trachomatis infection in 807 Dutch Caucasian women. A significant association of the NOD1 +32656 GG insertion variant with protection against infection with C. trachomatis has been detected [p: 0.0057; OR: 0.52]. When comparing C. trachomatis-positive women without symptoms to C. trachomatis-positive women with symptoms, and to C. trachomatis-positive women with TFI, we observed an increasing trend in carriage of the GG allele [Ptrend: 0.0003]. NOD2 1007fs failed to reveal an association. We hypothesize that the underlying mechanism might be a functional effect of the GG insertion on IFN-beta-dependent regulation of immune response in the genital tract. The research is part of an ongoing effort of identifying key polymorphisms that determine the risk of TFI and effectively translating them into the clinical setting for the purpose of optimizing diagnostic management of women at risk for developing TFI.

Ethnic differences in HSV1 and HSV2 seroprevalence in Amsterdam, the Netherlands

Herpes simplex virus type 1 (HSV1) and 2 (HSV2) infection can lead to significant morbidity, and HSV2 is considered a risk factor for HIV transmission. The majority of HSV-infected people are asymptomatic and unaware of their infection. We aimed to determine the HSV1 and HSV2 prevalence among various ethnic groups in a large urban area in the Netherlands. In 2004, serum samples from a population-based serum repository of 1,325 people over 18 years living in Amsterdam were tested for HSV1 and HSV2 antibodies in order to determine high-risk groups. Prevalence ratios were estimated and all analyses were weighted by sex, age, and ethnicity. In the general population of Amsterdam, 67% had HSV1 antibodies, 22% had HSV2 antibodies, 15% had HSV1 and HSV2 antibodies, and 26% had no indication of HSV infection. In multivariate analyses, HSV1 seroprevalence increased with age, and was higher among people of Turkish and Moroccan origin, homosexual men, and individuals with low educational level. HSV2 seroprevalence was associated with increasing age, Surinamese/Antillean background, and having a history of sexually transmitted infections (STI). These differences between ethnic groups in Amsterdam regarding the distribution of HSV1 and HSV2 infection emphasise the importance of an ethnic-specific approach of serological testing as well as campaigns aimed at behavioural change and counselling to raise awareness of the risk of HSV transmission.

Ethnic differences in HSV1 and HSV2 seroprevalence in Amsterdam, the Netherlands

Herpes simplex virus type 1 (HSV1) and 2 (HSV2) infection can lead to significant morbidity, and HSV2 is considered a risk factor for HIV transmission. The majority of HSV-infected people are asymptomatic and unaware of their infection. We aimed to determine the HSV1 and HSV2 prevalence among various ethnic groups in a large urban area in the Netherlands. In 2004, serum samples from a population-based serum repository of 1,325 people over 18 years living in Amsterdam were tested for HSV1 and HSV2 antibodies in order to determine high-risk groups. Prevalence ratios were estimated and all analyses were weighted by sex, age, and ethnicity. In the general population of Amsterdam, 67% had HSV1 antibodies, 22% had HSV2 antibodies, 15% had HSV1 and HSV2 antibodies, and 26% had no indication of HSV infection. In multivariate analyses, HSV1 seroprevalence increased with age, and was higher among people of Turkish and Moroccan origin, homosexual men, and individuals with low educational level. HSV2 seroprevalence was associated with increasing age, Surinamese/Antillean background, and having a history of sexually transmitted infections (STI). These differences between ethnic groups in Amsterdam regarding the distribution of HSV1 and HSV2 infection emphasise the importance of an ethnic-specific approach of serological testing as well as campaigns aimed at behavioural change and counselling to raise awareness of the risk of HSV transmission.

Rise in seroprevalence of herpes simplex virus type 1 among highly sexual active homosexual men and an increasing association between herpes simplex virus type 2 and HIV over time (1984-2003)

Objectives Herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2) are both highly prevalent. The rate of genital HSV-1 transmission is reportedly increasing over time. HSV-2 is considered to be an important risk factor for HIV transmission. We therefore studied changes in the HSV-1 and HSV-2 prevalence in a large cohort of men who have sex with men (MSM) over a 20-year time period. Methods Among 1847 HIV-infected and HIV-uninfected MSM participating in the Amsterdam Cohort Studies, seroprevalence of HSV-1 and HSV-2 was determined and prevalence rate ratios (PRR) and 95% confidence intervals were calculated. Results Between 1984 and 2003 the HSV-1 and HSV-2 prevalence decreased among HIV-uninfected MSM (P < 0.001), but remained stable among HIV-infected MSM. HSV-1 prevalence increased among men with at least 200 sexual partners over lifetime (PRR: 1.49, P < 0.001). The association between HIV infection and HSV-2 became stronger over time (PRR: 3.45, P < 0.001). Conclusions Seroprevalence of HSV-1 and HSV-2 remained high among HIV infected MSM from 1984 to 2003. The association of HIV and HSV-2 increased during the HIV epidemic. Since the proportion of sexual transmission of HSV-1 is rising, it is important to study the potential role of HSV-1 as risk factor for HIV acquisition.

Monitoring the potential introduction of the Swedish Chlamydia trachomatis variant (swCT) in the Netherlands

This report describes the actions of public health experts in cooperation with specialists in sexually transmitted diseases (STD), epidemiologists and (molecular) microbiologists to investigate the possible introduction of the swCT variant in the Netherlands: 1. Investigating trends in CT epidemiology Result: STD surveillance and laboratory surveillance did not show any evidence of the introduction of the swCT variant in Holland. 2. Retesting samples by TaqMan PCR Result: Roche CT-negative samples suspected to be CT-positive on the basis of the clinical picture were retested by swCT TaqMan but did not harbour the swCT variant 3. Screening sample pools for the presence of the swCT variant Result: Four different sample pools covering a wide geographical range were tested by specific swCT Taqman assay, but the swCT variant was not detected in any of them. In conclusion, to date the swCT variant has not been found in the Netherlands. However, ongoing monitoring is needed until Roche and Abbott have adapted their CT nucleic acid amplification tests (NAATs) to detect the new variant.

Population prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae in the Netherlands. Should asymptomatic persons be tested during population-based Chlamydia screening also for gonorrhoea or only if chlamydial infection is found?

BACKGROUND

Screening and active case finding for Chlamydia trachomatis (CT) is recommended to prevent reproductive morbidity. However insight in community prevalence of gonococcal infections and co-infections with Neisseria gonorrhoea (NG) is lacking.

METHODS

Nested study within a large population-based Chlamydia Screening Pilot among 21.000 persons 15-29 year. All CT-positive (166) and a random sample of 605 CT-negative specimens were as well tested for gonococcal infection.

RESULTS

Overall Chlamydia prevalence in the Pilot was 2.0% (95% CI: 1.7-2.3), highest in very urban settings (3.2%; 95% CI: 2.4-4.0) and dependent of several risk factors. Four gonococcal infections were found among 166 participants with CT infection (4/166 = 2.4%; 95% CI: 0.1%-4.7%). All four had several risk factors and reported symptoms. Among 605 CT-negative persons, no infection with NG could be confirmed.

CONCLUSION

A low rate of co-infections and a very low community prevalence of gonococcal infections were found in this population based screening programme among young adults in the Netherlands. Population screening for asymptomatic gonococcal infections is not indicated in the Netherlands. Although co-infection with gonorrhoea among CT-positives is dependent on symptoms and well-known algorithms for elevated risks, we advise to test all CT-positives also for NG, whether symptomatic or asymptomatic.

Description of the ICTI consortium: an integrated approach to the study of Chlamydia trachomatis infection

The use of an integrated approach to the study of Chlamydia trachomatis infection of the female genital tract, presented at the mini-symposium "Chlamydia trachomatis infections" and described in the thesis of Joseph M. Lyons, has resulted in the creation of the ICTI consortium. The ICTI consortium is based on strong interaction and collaboration between basic scientists, clinicians, epidemiologists, and health care policy makers. This translational approach will help to further the valuable insight into the immunopathogenesis of this sexually transmitted infection (STI) and the development of new intervention strategies, including the vaccines and screening programs necessary to effectively diagnose, treat and prevent C. trachomatis infection. A background of the need for this integrated approach is presented and the goals and participants of the consortium are described.

Slow epidemic of lymphogranuloma venereum L2b strain

We traced the Chlamydia trachomatis L2b variant in Amsterdam and San Francisco. All recent lymphogranuloma venereum cases in Amsterdam were caused by the L2b variant. This variant was also present in the 1980s in San Francisco. Thus, the current "outbreak" is most likely a slowly evolving epidemic.

Diagnostic and Clinical Implications of Anorectal Lymphogranuloma Venereum in Men Who Have Sex with Men: A Retrospective Case-Control Study

BACKGROUND

Recently, outbreaks of anorectal lymphogranuloma venereum (LGV) have occurred among men who have sex with men (MSM). This study identifies risk factors and clinical predictors of LGV to determine the implications for clinical practice.

METHODS

The Chlamydia trachomatis serovars for all MSM who had anorectal chlamydia diagnosed at a sexually transmitted infection clinic in Amsterdam, The Netherlands, in 2002 and 2003 were retrospectively typed; 87 persons were infected with C. trachomatis serovar L2b and received a diagnosis of LGV. MSM infected with C. trachomatis serovars A-K and who thus had non-LGV anorectal chlamydia (n = 377) and MSM who reported having receptive anorectal intercourse but who did not have anorectal chlamydia (n = 2677) served as 2 separate control groups. Risk factors and clinical predictors were analyzed by multivariate logistic regression. Receiver operating characteristic curves were used to determine clinical relevance.

RESULTS

HIV seropositivity was the strongest risk factor for LGV (odds ratio for patients with LGV vs. those with non-LGV chlamydia, 5.7 [95% confidence interval, 2.6-12.8]; odds ratio for patients with LGV vs. control subjects without chlamydia, 9.3 [95% confidence interval, 4.4-20.0]). Proctoscopic findings and elevated white blood cell counts in anorectal smear specimens were the only clinically relevant predictors for LGV infection (area under the curve of the receiver operating characteristic curve, > 0.71). Use of these 2 parameters and HIV infection status provided the highest diagnostic accuracy (for MSM with anorectal chlamydia, the area under the curve was > 0.82; sensitivity and specificity were 89% and 50%, respectively).

CONCLUSIONS

LGV testing is recommended for MSM with anorectal chlamydia. If routine LGV serovar typing is unavailable, we propose administration of syndromic LGV treatment for MSM with anorectal chlamydia and either proctitis detected by proctoscopic examination, > 10 white blood cells/high-power field detected on an anorectal smear specimen, or HIV seropositivity.

The CD14 functional gene polymorphism -260 C>T is not involved in either the susceptibility to Chlamydia trachomatis infection or the development of tubal pathology

BACKGROUND

The functional polymorphism -260 C>T in the LPS sensing TLR4 co-receptor CD14 gene enhances the transcriptional activity and results in a higher CD14 receptor density. Individuals carrying the T/T genotype also have significantly higher serum levels of soluble CD14. The T allele of this polymorphism has recently been linked to Chlamydia pneumoniae infection. We investigated the role of the CD14 -260 C>T polymorphism in the susceptibility to and severity (defined as subfertility and/or tubal pathology) of C. trachomatis infection in Dutch Caucasian women.

METHODS

The different CD14 -260 C>T genotypes were assessed by PCR-based RFLP analysis in three cohorts: 1) A cohort (n = 576) of women attending a STD clinic, 2) a cohort (n = 253) of women with subfertility, and 3) an ethnically matched control cohort (n = 170). The following variables were used in the analysis: In cohort 1 the CT-DNA status, CT IgG serology status, self-reported symptoms and in cohort 2, the CT IgG serology status and the tubal status at laparoscopy.

RESULTS

In the control cohort the CC, CT and TT genotype distribution was: 28.2%, 48.2%, and 23.5% respectively. No differences were found in the overall prevalence of CD14 -260 genotypes (28.1%, 50.7%, and 21.2%) in cohort 1 when compared to the control cohort. Also no differences were observed in women with or without CT-DNA, with or without serological CT responses, with or without symptoms, or in combinations of these three variables. In subfertile women with tubal pathology (cohort 2, n = 50) the genotype distribution was 28.0%, 48.0%, and 24.0% and in subfertile women without tubal pathology (n = 203), 27.6%, 49.3% and 23.2%. The genotype distribution was unchanged when CT IgG status was introduced in the analyses.

CONCLUSION

The CD14 -260 C>T genotype distributions were identical in all three cohorts, showing that this polymorphism is not involved in the susceptibility to or severity of sequelae of C. trachomatis infection.

New lymphogranuloma venereum Chlamydia trachomatis variant, Amsterdam

We retrospectively conducted a study of men who have sex with men who visited the Amsterdam, the Netherlands, sexually transmitted diseases clinic from January 2002 to December 2003 and had rectal Chlamydia trachomatis infections. We found that symptomatic (73%) as well as asymptomatic (43%) patients were infected with a new C. trachomatis LGV variant.

Interrelationship between polymorphisms of incA, fusogenic properties of Chlamydia trachomatis strains, and clinical manifestations in patients in The Netherlands

IncA variation among Dutch Chlamydia trachomatis isolates was investigated. Of 98 strains, two carried an incA with a premature stop codon, lacked IncA, and were nonfusogenic, while 96 contained an intact incA, expressed IncA, and were fusogenic. Among these 96 strains, nine IncA sequence types were found, of which the three most frequently encountered (88% of the strains) were randomly distributed among symptomatic and asymptomatic patients.

[Resistance of gonococci in the Netherlands; results of a survey of medical microbiology laboratories]

OBJECTIVE

To collect information about the incidence ofgonorrhoea and gonococcal resistance in the Netherlands.

METHOD

A questionnaire was sent to 39 medical microbiology laboratories to obtain information on current diagnostics and the susceptibility testing method, and on the number of positive results and the susceptibility pattern of gonococcal isolates in 2002 and 2003 (up to and including November).

RESULTS

32 laboratories participated in this survey. 13 laboratories used culture alone and 19 laboratories used culture and/or a molecular test. Gonorrhoea was diagnosed 2,666 times in 2002 and 2,190 times in 2003, with an incidence of 33.5 and 27.0 per 100,000 inhabitants, respectively. The rate of resistance to beta-lactam antibiotics (penicillin and amoxicillin) was 12.2% and 10.7% in 2002 and 2003, respectively, and the rates of resistance to tetracycline were 18.5% and 20.6%. An increase in the resistance to quinolones was observed from 6.6% in 2002 to 9.5% in 2003. Resistance to cephalosporins was low (0.5% in 2002 and 1.2% in 2003). Furthermore, regional differences in susceptibility were found within the Netherlands.

CONCLUSION

The observed gonococcal incidence and resistance form the basis for a gonorrhoea prevention and treatment programme in the Netherlands.

Prophylaxis and follow-up after possible exposure to HIV, hepatitis B virus, and hepatitis C virus outside hospital: evaluation of policy 2000-3

PROBLEM

Prophylactic treatment and follow-up after exposure to HIV, hepatitis B, and hepatitis C outside hospital needs to be improved.

BACKGROUND AND SETTING

Until January 2000, people in Amsterdam could report exposure outside hospital to either a hospital or the municipal health service. If they reported to the municipal health service, they were then referred to hospitals for HIV prophylaxis, whereas the municipal health service handled treatment and follow-up related to hepatitis B and hepatitis C and traced sources. For cases reported to a hospital, hospital staff often did not trace HIV sources or follow up patients for hepatitis B and hepatitis C.

KEY MEASURES FOR IMPROVEMENT

Providing adequate treatment for HIV, hepatitis B and hepatitis C after exposure for all reported exposures outside hospital.

STRATEGIES FOR CHANGE

On 1 January 2000, a new protocol was introduced in which three Amsterdam hospitals and the municipal health service collaborated in the treatment and follow-up of exposures outside hospital. Both municipal health service and hospitals can decide whether HIV prophylaxis is necessary and prescribe accordingly. All people exposed in the community who report to hospitals are subsequently referred to the municipal health service for further treatment and follow-up.

EFFECTS OF CHANGE

The protocol is effective in that most people comply with treatment and follow-up. When indicated, HIV prophylaxis is started soon after exposure. In nearly two thirds of cases the municipal health service traced and tested the source.

LESSONS LEARNT

Provision of treatment and follow-up in one place enables treatment, tracing and testing sources, and follow-up, including counselling and registration of all reported exposures in Amsterdam, which allows for swift identification of emerging epidemiological trends. Since May 2004 all Amsterdam hospitals have participated in the protocol.

Occupational exposure to bloodborne viruses in the Amsterdam police force, 2000-2003

OBJECTIVES

To assess and evaluate the rate and outcome of occupational exposure to hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) in the Amsterdam police force.

METHODS

Retrospectively, all accidents with risk for viral transmission reported to the Municipal Health Service between January 1, 2000 and December 31, 2003 were described and analyzed in 2004.

RESULTS

Over a 4-year period, 112 exposures with a viral transmission risk were reported (the estimated exposure rate was 68/10,000/year). Of these exposures, 89 (79%) sources were tested, finding 4% HBV-positive, 4% HIV-positive, and 18% HCV-positive. Immunoglobulin for HBV infection was given 44 times; HIV post-exposure prophylaxis was prescribed 16 times and 13 of 16 discontinued the course within a few days because the transmission source tested HIV-negative. No seroconversions were seen in persons exposed.

CONCLUSIONS

The rate of exposure is low. The majority of the sources could be traced and tested. However, a comprehensive and effective protocol is essential in minimizing the risk of occupational HBV, HCV, and HIV infection in police officers, even if HBV vaccination is provided.

[Inguinal lymphogranuloma venereum in a man having sex with men: perhaps an example of the missing link to explain the transmission of the recently identified anorectal epidemic]

A 38-year-old man who had sex with men, presented at the outpatient department for Sexually Transmitted Diseases in Amsterdam with a painful, red, fluctuating swelling in the left groin and general discomfort. He had been sexually active in the population of men who have sex with men, in which an anorectal lymphogranuloma venereum (LGV) epidemic has recently been discovered. Unlike other cases where there was anorectal involvement, this patient was the first case of LGV with the classical inguinal presentation although he had not visited the tropics where the inguinal form of LGV occurs as an STD. Routine investigation using PCR on material from urethra and rectum and from the urine, repeatedly failed to detect LGV. However, PCR on pus aspirated from the enlarged lymph node demonstrated Chlamydia trachomatis serovar type L2. Treatment with doxycycline 100 mg twice daily was started. This case illustrates that routine analysis from urethra and rectum and of urine may fail to detect LGV. Furthermore, this case of a patient who probably had LGV initially in the urethra may be the missing link in explaining the route of transmission of the anorectal LGV epidemic.

Identification of a new human coronavirus

Three human coronaviruses are known to exist: human coronavirus 229E (HCoV-229E), HCoV-OC43 and severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV). Here we report the identification of a fourth human coronavirus, HCoV-NL63, using a new method of virus discovery. The virus was isolated from a 7-month-old child suffering from bronchiolitis and conjunctivitis. The complete genome sequence indicates that this virus is not a recombinant, but rather a new group 1 coronavirus. The in vitro host cell range of HCoV-NL63 is notable because it replicates on tertiary monkey kidney cells and the monkey kidney LLC-MK2 cell line. The viral genome contains distinctive features, including a unique N-terminal fragment within the spike protein. Screening of clinical specimens from individuals suffering from respiratory illness identified seven additional HCoV-NL63-infected individuals, indicating that the virus was widely spread within the human population.

HIV incidence on the increase among homosexual men attending an Amsterdam sexually transmitted disease clinic: using a novel approach for detecting recent infections

OBJECTIVE

Dramatic increases have occurred in sexually transmitted diseases (STD) and in sexual risk behaviour among homosexual men in Amsterdam and internationally. We investigated whether these trends indicate a resurgence of the HIV epidemic.

METHODS

HIV incidence was determined among homosexual attendees of an STD clinic in Amsterdam, who had participated in semi-annual anonymous unlinked cross-sectional HIV prevalence studies from 1991 to 2001. Stored HIV-seropositive samples were tested with a less-sensitive HIV assay and, if non-reactive, were further tested for the presence of antiretroviral drugs, indicative of the use of highly active antiretroviral therapy. Seropositive men who tested non-reactive on the less-sensitive assay and had not used antiretroviral drugs were classified as recently infected (< 170 days). Annual HIV incidence and its changes were examined.

RESULTS

Among 3090 homosexual participants (median age 34 years), 454 were HIV infected, of whom 37 were recently infectioned. From 1991 to 2001 the overall incidence was 3.0 infections/100 person-years. Incidence increased over time (P = 0.02) and, strikingly, the increase was evident in older (> or = 34 years) men (P < 0.01), but not in the young. Of men recently infected, 84% (n = 31) were unaware of their infection and 70.3% (n = 26) had a concurrent STD. These 26 men reportedly had sex with a total of 315 men in the preceding 6 months.

CONCLUSION

HIV incidence is increasing among homosexual attendees of an STD clinic. It is imperative to trace recently infected individuals, because they are highly infectious, and can thus play a key role in the spread of HIV.

[Syphilis epidemic and an increase of the number of HIV infections among homosexual men attending the Amsterdam venereal disease clinic]

The registered number of cases of early infectious syphilis and of (ano)genital gonorrhoea among the attendees of the outpatient clinic for sexually transmitted diseases of the Amsterdam municipal health service shows a strong increase for both diagnoses in the period 1990-2001, notably in the last few years. Nearly all of this increase is accounted for by homosexual men. Syphilis increased mostly among men aged 35 years and over, gonorrhoea mostly among younger men. The population of older men also showed a distinct increase since 1997 in HIV incidence.

[Increased Neisseria gonorrhoeae quinolone resistance in Amsterdam]

In addition to a rise in the number of cases of gonorrhoea, the susceptibility of Neisseria gonorrhoeae to antibiotics is also a cause for concern. After a period of high resistance rates to penicillin and tetracycline between 1985 and 1995, resistance rates have dropped considerably in recent years, probably due to changes in treatment regimens. However, recently we have seen an increasing number of quinolone-resistant N. gonorrhoeae isolates in Amsterdam, the Netherlands, a development that has previously been reported in other parts of the world. Some form of national resistance monitoring for gonococci is therefore urgently required to allow timely detection of changes in N. gonorrhoeae resistance.

Amplified fragment length polymorphism fingerprinting for identification of a core group of Neisseria gonorrhoeae transmitters in the population attending a clinic for treatment of sexually transmitted diseases in Amsterdam, The Netherlands

Amplified fragment length polymorphism analysis seems well suited for studying the epidemiology of isolates of Neisseria gonorrhoeae obtained from patients attending the Sexually Transmitted Disease Outpatient Clinic in Amsterdam, The Netherlands. It shows potential to identify the core group of transmitters.

Prevalence and risk factors of HSV-1 and HSV-2 antibodies in European HIV infected women

OBJECTIVES

To investigate the prevalence and risk factors of HSV-1 and HSV-2 antibodies in HIV infected women and the association between recurrent genital ulcerations and HIV disease progression in HSV-2 positive women.

METHODS

The presence of HSV antibodies was tested in 276 of the 487 women participating in a European cohort study of HIV infected women. Prevalence rate ratios described the association between HSV infection and its risk factors, using log binomial regression. Generalised estimating equations (GEE) analysis was performed to determine the impact of markers of HIV disease progression on recurrent genital ulcerations.

RESULTS

The prevalence of HSV-1 and HSV-2 antibodies was 76% (95% confidence interval (95% CI): 71-81) and 42% (95% CI: 36-50); 30% (95% CI: 24-35) of the women had antibodies against both HSV-1 and HSV-2. The prevalence of HSV-1 was 86% (95% CI: 80-92) in southern Europe compared with 69% (95% CI: 57-79) and 67% (95% CI: 55-77) in central and northern Europe (p=0.002). This geographical variation remained after adjustment for other risk factors. An increasing number of years of sexual activity (p=0.0002) and a history of prostitution (p=0.0001) were independently associated with HSV-2 prevalence. In HSV-2 positive women, symptomatic cases of HSV infection were minimal, but increased with decreasing CD4 count.

CONCLUSION

In HIV infected women, the prevalence of HSV antibodies is high and symptomatic cases of HSV infection are minimal, but increase with decreasing CD4 count. HSV-2 but not HSV-1 was related to sexual behaviour (that is, a history of prostitution and the number of sexually active years) in this group of HIV infected women.

Antimicrobial resistance of Neisseria gonorrhoeae and emerging ciprofloxacin resistance in the Netherlands, 1991 to 1998

Surveillance of antibiotic resistance in Neisseria gonorrhoeae showed a decrease in the percentage of beta-lactamase-producing isolates but an increase in intermediately penicillin-resistant strains and strains resistant to a high level of tetracycline. MICs for the ciprofloxacin-resistant isolates that emerged increased, and these isolates had mutations in gyrA and parC similar to those observed in the Far East.

Biofilm production by Staphylococcus epidermidis isolates associated with catheter related bacteremia

The mean biofilm production of 22 Staphylococcus epidermidis isolates associated with catheter related bacteremia was significantly higher than that of 32 nose isolates from healthy individuals. This difference was due to seven catheter related isolates. These findings do not show a clear association between biofilm production and virulence.

Effectiveness of resins in neutralizing antibiotic activities in bactec plus Aerobic/F culture medium

Incorporating resins in blood culture media can effectively reduce the activities of several antibiotics. It was shown that the activities of some generally used antibiotics decreased by 80 to 90% within 2 h in Bactec Plus Aerobic/F resin-containing culture medium. Bactec vials containing resins were still found to be positive for bacteria when antibiotics were present. The addition of beta-lactamase shortened the detection time irrespective of the presence of resins.

Binding of blood coagulation factor VIII and its light chain to phosphatidylserine/phosphatidylcholine bilayers as measured by ellipsometry

Factor VIII is a plasma protein which plays an essential role in the coagulation system. When assembled with the enzyme Factor IXa on a phospholipid membrane, it functions as a cofactor in the enzyme complex that cleaves the zymogen Factor X to Factor Xa. We studied the binding of both Factor VIII and the Factor VIII light chain to planar phospholipid bilayers consisting of 25% dioleoylphosphatidylserine and 75% dioleoylphosphatidylcholine (PSPC) by ellipsometry. Equilibrium-binding studies revealed that both Factor VIII and its light chain bind with high affinity to PSPC bilayers. The binding affinity of Factor VIII, with a dissociation constant Kd of 0.24 nM, was comparable with that of the Factor VIII light chain (Kd 0.49 nM). Maximal binding was 2.3 mmol of protein per mol of PSPC for Factor VIII and 7.1 mmol of protein per mol of PSPC for the Factor VIII light chain. Adsorption kinetics of both Factor VIII and its light chain conformed to the classical Langmuir adsorption model yielding dissociation constants calculated from the rates of adsorption that were similar to those obtained by equilibrium-binding studies. In contrast, measurements of rates of desorption revealed a deviation from those expected for a single class of binding sites. The desorption rate of Factor VIII increased with increasing residence time on the lipid membrane. This indicates transition of Factor VIII to a configuration with a lower binding affinity. As this time-dependent change in affinity could affect the validity of the measurement of binding parameters, in particular equilibrium-binding determinations carried out on a long timescale, binding affinity was also estimated from adsorption kinetics at half-maximal surface coverage, a relatively rapid procedure for the determination of the affinity. A Kd of 0.087 nM was obtained under these conditions. Measurement of equilibrium binding to small PSPC vesicles, a system in which equilibrium is rapidly attained, resulted in similar binding parameters (Kd = 0.13 nM and a maximal binding of 2.8 mmol of protein per mol of PSPC). These data confirm the results of equilibrium binding to planar bilayers. Taken together, our results indicate that Factor VIII, by means of its 80 kDa light chain, binds to PSPC bilayers with a dissociation constant below the concentration of Factor VIII in plasma and therefore may readily bind to exposed phospholipid membranes under physiological conditions.

Treatment with monoclonal anti-CD3 antibody protects against lethal Sendai virus infection by induction of natural killer cells

C57BL/6 mice are protected from a lethal pneumonia caused by Sendai virus when treated with low doses of mAb directed to the CD3 Ag. The protective mechanism is not due to an accelerated Sendai virus-specific Th cell, CTL, or antibody response but to a strong NK cell response via the in vivo induction of lymphokines. Antibodies directed against the NK1.1 and asialo GM1 marker totally reversed the protective effect of anti-CD3 treatment. In vivo treatment with rIL-2 also induced NK activity and induced antiviral protection. Treatment with anti-CD3 protects when given in a narrow time window (1 day before until 1 day after Sendai virus inoculation), indicating that NK activity is protective in the early phase of virus infection.

Treatment with monoclonal anti-CD3 antibody protects against lethal Sendai virus infection by induction of natural killer cells

C57BL/6 mice are protected from a lethal pneumonia caused by Sendai virus when treated with low doses of mAb directed to the CD3 Ag. The protective mechanism is not due to an accelerated Sendai virus-specific Th cell, CTL, or antibody response but to a strong NK cell response via the in vivo induction of lymphokines. Antibodies directed against the NK1.1 and asialo GM1 marker totally reversed the protective effect of anti-CD3 treatment. In vivo treatment with rIL-2 also induced NK activity and induced antiviral protection. Treatment with anti-CD3 protects when given in a narrow time window (1 day before until 1 day after Sendai virus inoculation), indicating that NK activity is protective in the early phase of virus infection.