Anneke van den Hoek

High prevalence of syphilis and other sexually transmitted diseases among sex workers in China: potential for fast spread of HIV.

ObjectivesIn China, in the early 1980s, sexually transmitted diseases (STD) started to increase steeply. Sex workers and their clients appeared to play an important role in the spread of STD. Prostitution is illegal in China, and therefore no specific services exist for sex workers unless they are arrested and detained in re-education centres. Staff of a maternal and neonatal hospital in Guangzhou felt the need for an STD care and prevention programme for sex workers outside detention, and started a programme within their hospital, which was unique in the Chinese context. MethodsFrom March 1998 to mid-October 1999 sex workers were recruited through various outreach methods, and were interviewed, counselled and examined for the presence of STD/HIV. ResultsA total of 966 women, originating from all over China but working in Guangzhou, entered the programme. The median duration of prostitution was one year, and the median number of clients was seven per week. Antibodies to HIV were present in 1.4%. The prevalence of STD was very high: syphilis 14%, Chlamydia trachomatis 32%, gonorrhoea 8% and trichomoniasis 12.5%. Knowledge about STD/HIV transmission and condom use was poor. ConclusionGiven the high prevalence of STD, the potential for the further spread of HIV is clearly present. STD care and prevention programmes for these women, outside detention, are urgently needed, and appear also to be feasible in China.

Human immunodeficiency virus infection and other risk factors for skin abscesses and endocarditis among injection drug users.

OBJECTIVE To study incidence rates of and risk factors for skin abscesses at the site of injection and episodes of endocarditis among injection drug users (IDU). DESIGN A comprehensive, open cohort study of drug users on the natural history of human immunodeficiency virus (HIV) infection. METHODS From 1986 to 1994, injection drug users in Amsterdam were included in the study. Incidence rates of self-reported skin abscesses and verified episodes of endocarditis were calculated. In uni- and multivariate Poisson regression analysis, risk factors for skin abscesses and endocarditis were determined. RESULTS 521 HIV-seronegative and 237 HIV-seropositive IDU were followed for 1640 person-years. A total of 545 skin abscesses were reported by 269 IDU (incidence 33/100 person-years). HIV infection, female gender, prostitution among females, foreign nationality, injection of heroin and cocaine, a high frequency of injecting, and obtaining syringes through the needle exchange program were independently and positively associated with skin abscesses. During follow-up, 17 verified episodes of endocarditis were observed (incidence 1.3/100 person-years). Endocarditis was independently associated with HIV infection and a previous history of endocarditis. Furthermore, women and IDU with a skin abscess appeared to be at an increased risk for endocarditis. CONCLUSIONS HIV infection is an independent risk factor for skin abscesses and endocarditis. Also, women are at an increased risk for these injection-related infections. Prevention activities, like promotion of skin cleaning, should be directed at those IDU in whom one or more risk factors have been identified.

Pregnancies before and after HIV diagnosis in a European cohort of HIV-infected women.

ObjectivesBecause most HIV-infected women are of reproductive age, we investigated whether their reproduction planning was affected by their HIV diagnosis. DesignThe European women study is a prospective, multicentre cohort of 485 HIV-infected women with a known interval of seroconversion. MethodsThe incidence of pregnancy was measured with person–time methods. Generalized estimating equation analysis was used to determine risk factors for pregnancy and pregnancy outcomes. ResultsIn 449 women, the age-adjusted incidence of pregnancies decreased from 8.6 before HIV diagnosis to 8.2 and 6.0 per 100 person-years in 0–4 and over 4 years after HIV diagnosis, respectively (P = 0.14). The proportion of induced abortions increased from 42% before to 53% after HIV diagnosis (P < 0.05). The risk of spontaneous abortion did not increase as a result of HIV infection. Since 1995, the proportion of births increased (P = 0.009), whereas that of induced abortions decreased (P = 0.01) compared with earlier years. An increased risk of pregnancy after HIV diagnosis was found in northern and central European women compared with southern European women; there was a lower risk in single women than in women with a steady partner. Of all pregnant women, single women, women between 15 and 25 years of age, and women with multiple partners were at increased risk for induced abortion both before and after HIV diagnosis. ConclusionThe incidence of pregnancy decreased with HIV disease progression. Pregnancies after HIV diagnosis appear to be related largely to social and cultural attitudes. The number of induced abortions was high before HIV diagnosis and it significantly increases thereafter.

Two Years’ Prospective Collection of Molecular and Epidemiological Data Shows Limited Spread of Hepatitis A Virus outside Risk Groups in Amsterdam, 2000–2002

We performed a viral sequencing study on samples representing all reported primary cases of acute hepatitis A virus (HAV) infection reported for 2 years in Amsterdam. Two regions of HAV RNA were amplified, sequenced, and used for phylogenetic analysis. Of 156 cases, strains of 104 isolates (66.6%) clustered into 3 genotypes: 1A, 1B, and 3. Two separate transmission circles occurred, without mutual interrelation. In genotype 1A, 4 clusters occurred in men having sex with men (MSM), and the fifth cluster was related to a virus from Morocco. In genotype 1B, 6 small clusters were directly related to the Moroccan virus. In genotype 3, strains were related to a virus from Pakistan. Our analysis indicates that, to stop transmission of HAV in Amsterdam, the entire MSM population and travelers to countries where HAV is endemic, especially children, should be vaccinated. Prevention strategies need not include the vaccination of all children living in Amsterdam.

Trends in HIV postexposure prophylaxis prescription and compliance after sexual exposure in Amsterdam, 2000-2004

Objective: The objective of this study was to evaluate trends in HIV postexposure prophylaxis (PEP) requests after sexual exposure, compliance, and outcome of follow-up HIV tests. Study Design: The authors conducted a retrospective analysis of all HIV PEP requests after sexual exposure between January 1, 2000, and December 31, 2004, in Amsterdam. Results: In 5 years, there was a very modest increase in PEP requests, of which most (75%) came from men who have sex with men (MSM). Although 70% reported side effects, 85% completed their PEP course. Sexual assault victims less often completed their course (odds ratio [OR] = 0.1; 95% confidence interval [CI] = 0.05–0.4, P = 0.001). People who used HIV PEP more often complied with follow-up tests than people who did not use PEP (OR = 3.5; 95% CI = 1.6–7.9, P = 0.002). One HIV seroconversion was found caused by a later exposure than that for which PEP was given. Conclusions: Despite a widely available PEP program in Amsterdam, the number of PEP requests remained low. Most people completed their PEP course; compliance with follow-up HIV testing was high.

Determinants of high-risk sexual behavior Among immigrant groups in Amsterdam: Implications for interventions

Objectives: To determine predictors for sexual risk behavior among immigrant men in Amsterdam. Methods: From May 1997 to July 1998, 650 men from Surinam, the Antilles, and Ghana were recruited by convenience sampling. Multivariate logistic regression was used to find independent predictors for 1) multiple sex partners (>sexual 1 partner in the past year), 2) unprotected sex with casual partners in The Netherlands, 3) sexual activity in country of origin, and 4) unprotected sex in country of origin. Results: 1) Multiple sex partners were reported by 50% of respondents. Independent predictors were a recent infection with a sexually transmitted disease (STD), youth, low educational level, Afro‐Surinamese origin, lack of a long‐term relationship and history of commercial sex contact. 2) Unprotected sex occurred in 24% of casual partnerships. Independent predictors were a recent STD infection, low educational level, use of hard drugs, age between 20 and 29, few sexual partners, unprotected sex in country of origin, and a partner from the respondents ethnic group. 3) During the past 5 years, 24% were sexually active in country of origin. Independent predictors were Ghanaian origin, age over 20, a relatively high income, and multiple partners. 4) Unprotected sex occurred in 39% of the partnerships in country of origin. Independent predictors were low educational level, history of STDs, lack of health insurance, Ghanaian origin, frequent visits to home country, few sexual partners, and unprotected sex with casual partners in The Netherlands. Conclusion: Among immigrant men in Holland, important target groups for AIDS prevention programs have been identified. Men who visit their country of origin should be made aware of the risk of sexual contact with local women. Furthermore, it should be taken into account that immigrant men use condoms less frequently with women of their own ethnic group than with Dutch women.

Differences in progression to AIDS between injection drug users and homosexual men with documented dates of seroconversion

&NA; We compared rates of progression to AIDS for 99 injection drug users and 120 homosexual men with documented dates of HIV‐1 seroconversion. The crude risk of developing AIDS was higher among homosexual men than injection drug users [relative hazard (RH) = 2.4; 95% confidence interval (CI) = 1.3‐4‐4]. The relative hazard was slightly smaller among participants with a seroconversion interval of ≤1 year (RH = 2.2; 95% CI = 1.0‐5.2). The effect was partially explained by the inclusion of Kaposis sarcoma in the AIDS case definition. Excluding those with Kaposis sarcoma, the relative hazard was 2.0 (95% CI = 1.1‐3.8). Using the 1993 AIDS case definition decreased the effect (RH = 1.9; 95% CI = 1.1‐3.4). Finally, the high pre‐AIDS mortality among injection drug users could partially explain the difference in progression rate between injection drug users and homosexual men. Combining the effect of the above‐mentioned factors resulted in a relative hazard of 1.3 (95% CI = 0.7‐2.6). Thus, the slower progression to AIDS among injection drug users compared with homosexual men was largely explained by differences in the spectrum of AIDS‐defining illnesses, pre‐AIDS mortality, and length of seroconversion interval. (Epidemiology 1996;7:571‐577)

Symptoms of Infectious Diseases in Immunocompromised Travelers: A Prospective Study With Matched Controls

BACKGROUND Immunocompromised travelers to developing countries are thought to have symptomatic infectious diseases more often and longer than non-immunocompromised travelers. Evidence for this is lacking. This study evaluates whether immunocompromised short-term travelers are at increased risk of diseases. METHODS A prospective study was performed between October 2003 and May 2010 among adult travelers using immunosuppressive agents (ISA) and travelers with inflammatory bowel disease (IBD), with their non-immunocompromised travel companions serving as matched controls with comparable exposure to infection. Data on symptoms of infectious diseases were recorded by using a structured diary. RESULTS Among 75 ISA, the incidence of travel-related diarrhea was 0.76 per person-month, and the number of symptomatic days 1.32 per month. For their 75 controls, figures were 0.66 and 1.50, respectively (p > 0.05). Among 71 IBD, the incidence was 1.19, and the number of symptomatic days was 2.48. For their 71 controls, figures were 0.73 and 1.31, respectively (p > 0.05). These differences also existed before travel. ISA had significantly more and longer travel-related signs of skin infection and IBD suffered more and longer from vomiting. As for other symptoms, no significant travel-related differences were found. Only 21% of immunocompromised travelers suffering from diarrhea used their stand-by antibiotics. CONCLUSIONS ISA and IBD did not have symptomatic infectious diseases more often or longer than non-immunocompromised travelers, except for signs of travel-related skin infection among ISA. Routine prescription of stand-by antibiotics for these immunocompromised travelers to areas with good health facilities is probably not more useful than for healthy travelers.

Travel-related Dengue Virus Infection, the Netherlands, 2006-2007

To assess the incidence of and risk factors for clinical and subclinical dengue virus (DENV) infection, we prospectively studied 1,207 adult short-term travelers from the Netherlands to dengue-endemic areas. Participants donated blood samples for serologic testing before and after travel. Blood samples were tested for antibodies against DENV. Seroconversion occurred in 14 (1.2%) travelers at risk. The incidence rate was 14.6 per 1,000 person-months. The incidence rate was significantly higher for travel during the rainy months. Dengue-like illness occurred in 5 of the 14 travelers who seroconverted. Seroconversion was significantly related to fever, retro-orbital pain, myalgia, arthralgia, and skin rash. The risk for DENV infection for short-term travelers to dengue-endemic areas is substantial. The incidence rate for this study is comparable with that in 2 other serology-based prospective studies conducted in the 1990s.

Fecal-orally transmitted diseases among travelers are decreasing due to better hygienic standards at travel destination.

OBJECTIVE To evaluate whether changes in attack rates of fecal-orally transmitted diseases among travelers are related to changes in pretravel vaccination practices or better hygienic standards at travel destination. METHODS National surveillance data on all laboratory-confirmed cases of travel-related hepatitis A, shigellosis, and typhoid fever diagnosed in the Netherlands from 1995 to 2006 were matched with the number of Dutch travelers to developing countries to calculate region-specific annual attack rates. Trends in attack rates of non-vaccine-preventable shigellosis were compared with those of vaccine-preventable hepatitis A and typhoid fever. Trends were also compared with three markers for hygienic standards of the local population at travel destinations, drawn from the United Nations Development Programme database: the human development index, the sanitation index, and the water source index. RESULTS Attack rates among Dutch travelers to developing regions declined for hepatitis A, shigellosis, and typhoid fever. Region-specific trends in attack rates of shigellosis resembled trends of hepatitis A and typhoid fever. Declining attack rates of the three fecal-orally transmitted diseases correlated with improvements in socioeconomic, sanitary, and water supply conditions of the local population at travel destination. CONCLUSIONS These findings suggest that improved hygienic standards at travel destination strongly contributed to the overall decline in attack rates of fecal-orally transmitted diseases among visiting travelers.