Immigration from areas of high incidence is thought to have fueled the resurgence of tuberculosis (TB) in areas of low incidence. To reduce the risk of disease in low-incidence areas, the main countermeasure has been the screening of immigrants on arrival. This measure is based on the assumption of a prompt decline in the incidence of TB in immigrants during their first few years of residence in a country with low overall incidence. We have documented that this assumption is not true for 619 Somali immigrants reported in Denmark as having TB. The annual incidence of TB declined only gradually during the first 7 years of residence, from an initial 2,000 per 100,000 to 700 per 100,000. The decline was described by an exponential function with a half-time of 5.7 (95% confidence interval 4.0 to 9.7) years. This finding seriously challenges the adequacy of the customary practice of screening solely on arrival.

Cancer patterns among broad populations of homosexual men and women have not been studied systematically. The authors followed 1,614 women and 3,391 men in Denmark for cancer from their first registration for marriage-like homosexual partnership between 1989 and 1997. Ratios of observed to expected cancers measured relative risk. Women in homosexual partnerships had cancer risks similar to those of Danish women in general (overall relative risk (RR) = 0.9, 95% confidence interval (CI): 0.6, 1.4), but only one woman developed cervical carcinoma in situ versus 5.8 women expected (RR = 0.2, 95% CI: 0.0, 0.97). Overall, men in homosexual partnerships were at elevated cancer risk (RR = 2.1, 95% CI: 1.8, 2.5), due mainly to human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS)-associated Kaposi's sarcoma (RR = 136, 95% CI: 96, 186) and non-Hodgkin's lymphoma (RR = 15.1, 95% CI: 10.4, 21.4). Anal squamous carcinoma also occurred in excess (RR = 31.2, 95% CI: 8.4, 79.8). After exclusion of Kaposi's sarcoma, non-Hodgkin's lymphoma, and anal squamous carcinoma, no unusual cancer risk remained (RR = 1.0, 95% CI: 0.8, 1.3). With anal squamous carcinoma and HIV/AIDS-associated cancers as notable exceptions in men, cancer incidence rates among homosexual persons in marriage-like partnerships are similar to those prevailing in society at large.

We analysed the AIDS-defining diseases in all 618 notified AIDS patients in Denmark by June 30, 1990, and looked for trends and associations over time. Pneumocystis carinii pneumonia (PCP) was the most commonly reported disease (47%), and showed some but insignificant changes over time. The number of patients reported with Kaposi's sarcoma (KS) declined significantly from 33% in 1980-84 to 12% in 1990. KS was reported 5 times as often in homosexual men as in all other AIDS patients while esophageal candidiasis was reported in one fifth of the patients and were reported twice as often in women as in homosexual men. Wasting and HIV encephalopathy were 2.5 times more often reported in women than in homosexual men. The overall survival rate was 56% (95% confidence interval: 51-61%) at 1 year and 21% (95% confidence interval: 15-28%) at 3 years. Significantly improved survival over time was observed in patients diagnosed with PCP. Patients reported with KS had a significantly better prognosis than those with PCP. Women in general had a bad prognosis.

A total of 151 women at risk of human immunodeficiency virus infection were investigated, to study the strength of the association between cervix and anus regarding the presence of HPV and cytological abnormality. An equal percentage of women had abnormal cervical (12.2%) and anal (12.1%) Papanicolaou smears. HPV measured by PCR was detected in 93.3% of cervical squamous intraepithelial lesions (SIL) compared to 49.1% of normal cervical cytologies, and in 100% of anal SIL and 67.4% of normal anal cytologies, respectively. After controlling for HPV-PCR status, immunodeficiency, as measured by a low CD4+ count and HIV positivity, increased the detection of cervical and to some extent anal squamous intraepithelial lesions (SIL). We evaluated how precisely an HPV test could predict cervical disease and found that the HPV-PCR test was slightly more sensitive than the HPV-hybrid capture (HC) test (PCR: 93.3% vs. HC: 88.9%), whereas the HC test was significantly more specific (83.6% vs. 50.9%), and with a much higher positive predictive value (43.2% vs. 20.6%). Similar results were obtained for anal SIL. HIV positivity increased sensitivity, lowered specificity and increased the positive predictive value of the tests. A diagnosis of cervical SIL was associated with a more than 3-fold increased risk of a simultaneous abnormal anal smear (p < 0.05). In conclusion, cervical and anal disease were significantly associated and almost exclusively seen in the presence of HPV. Immunodeficiency and HIV positivity increased the risk of disease in HPV-positive subjects. Hybrid capture, which requires a higher viral load than PCR to detect HPV, was clearly superior in predicting cervical and anal disease. Altogether, these findings suggest that a high level of HPV infection may be important for the development of SIL in the population studied.

Diagnosis of gonorrhoea indicates that relatively recent unprotected sex has been practised and thus there is possibly a risk of HIV transmission. A retrospective analysis of gonorrhoea cases reported to the Danish national surveillance system was carried out for the period 1994-1999. The analysis included demographic pattern and mode of transmission of gonorrhoea in Denmark with the focus on trends and factors related to infection in men who have sex with men (MSM). We found that 646 (82.7%) reported cases of gonorrhoea were men, among whom 41.2% cases were due to sex with men, 52.9% were transmitted by heterosexual contact and 5.9% were due to unknown causes. The estimated mean annual reported incidence of gonorrhoea was more than 30 times greater among MSM than among heterosexual men and 6 times greater in MSM known to be HIV-positive, when gonorrhoea was diagnosed, than among other MSM (p < 0.001). No difference was found between the sites of infection among HIV-positive and HIV-negative MSM. A trend towards increase in the annual incidence of gonorrhoea has been seen since 1997, with an increase of 35% from 1997 to 1998 and a further increase of 41% from 1998 to 1999. The increase was mainly due to an increasing number and proportion of cases among MSM. The notified cases comprised 49% of patients with laboratory-confirmed gonorrhoea, which indicates a similar increasing trend. In conclusion, the rising trend of incident gonorrhoea, especially in MSM, may indicate a relapse to more unsafe sexual practices, which could lead to the spread of HIV infection. The higher incidence among HIV-positive MSM compared with other men underlines this concern.