Determinants of late HIV diagnosis among different transmission groups in Finland from 1985 to 2005.

OBJECTIVES: To study determinants of late HIV diagnosis in a low-HIV-prevalence (<0.1%) country where HIV spread among men who have sex with men (MSM) and heterosexuals in the 1980s, and among injecting drug users (IDUs) in the late 1990s. METHODS: Newly diagnosed HIV cases referred to the Helsinki University Central Hospital between 1985 and 2005 were reviewed to identify determinants of late HIV diagnosis, defined as diagnosis when the first CD4 count was <200 cells/microL, or when AIDS occurred within 3 months of HIV diagnosis. Determinants of late diagnosis were analysed using multivariate logistic regression. RESULTS: Among 934 HIV cases, 211 (23%) were diagnosed late. In the first 4-year interval of each sub-epidemic (1985-1989 for MSM and heterosexuals, 1998-2001 for IDUs), rates of late HIV diagnosis were 13%, 18% and 6%, respectively, but increased thereafter to 29%, 27% and 37%. Late diagnosis was associated with non-Finnish ethnicity, older age, male gender, lack of earlier HIV testing, diagnosis at health care settings and later stage of the sub-epidemic. CONCLUSIONS: The lower rate of late diagnosis in the first 4-year interval of each HIV sub-epidemic suggests that the early stages of the HIV epidemic in Finland were detected early. This factor may have contributed to the low prevalence of HIV infection in Finland. The stage and age of the epidemic should be taken into account when interpreting the data on late HIV diagnosis, especially in cross-country comparisons.

Control of methicillin-resistant Staphylococcus aureus outbreak involving several hospitals.

This population-based, retrospective, cohort study describes a large methicillin-resistant Staphylococcus aureus (MRSA) epidemic caused by one strain (E1) in the greater Helsinki region. The epidemic comprised 210 cases at several hospitals, but was finally controlled. The study period ranged from June 1991 to December 2000. The epidemic peaked in 1993-1995 with 143 cases (68% of total cases). From August 1993, all MRSA-positive cases at the eight municipal hospitals were isolated and barrier nursed. Contacts were cohorted and screened for MRSA colonization. Decolonization treatment was administered to some chronic carriers. MRSA cases and contacts were identified in the joint patient register of the municipal hospitals from August 1993. The annual incidence of MRSA E1 in Helsinki City area per 100,000 inhabitants rose from 0.2 in 1991 to 13.6 in 1994. It decreased from 1995, reaching 0.7 per 100,000 in 2000. A jointly agreed policy on MRSA and timely co-operation between all units were essential for control of this epidemic.

Sources of disseminated Mycobacterium avium infection in AIDS.

OBJECTIVES: To identify the sources of disseminated Mycobacterium avium complex (MAC) infection in AIDS. METHODS: HIV positive subjects with CD4 counts <100/mm(3) in Atlanta, Boston, New Hampshire and Finland were entered in a prospective cohort study. Subjects were interviewed about potential MAC exposures, had phlebotomy performed for determination of antibody to mycobacterial lipoarabinomannin and for culture. Patient-directed water samples were collected from places of residence, work and recreation. Patients were followed for the development of disseminated MAC. Univariate and multivariate risk factors for MAC were analyzed. RESULTS: Disseminated MAC was identified in 31 (9%) subjects. Significant risks in univariate analysis included prior Pneumocystis carinii pneumonia (PCP) (hazard ratio 1.821), consumption of spring water (4.909), consumption of raw seafood (34.3), gastrointestinal endoscopy (2.894), and showering outside the home (0.388). PCP, showering and endoscopy remained significant in a Cox proportional hazards model. There was no association between M. avium colonization of home water and risk of MAC. In patients with CD4<25, median OD antibody levels to lipoarabinomannin at baseline were 0.054 among patients who did not develop MAC and 0.021 among patients who did develop MAC (P=0.077). CONCLUSIONS: MAC infection results from diverse and likely undetectable environmental and nosocomial exposures. Mycobacterial infection before HIV infection may confer protection against disseminated MAC in advanced AIDS.

High rates of disseminated infection due to non-tuberculous mycobacteria among AIDS patients in Finland.

OBJECTIVE: to determine the rate of disseminated infection due to non-tuberculous mycobacteria (NTM) among Finnish AIDS patients, and to analyse the epidemiology of these infections. METHODS: in a prospective cohort study HIV-infected patients with CD4 counts < 200 x 10(6)/l were interviewed, and had mycobacterial blood cultures performed at baseline and at 6 months, then subsequently for clinical indications; autopsies were performed on patients who died. The cohort was followed at least for 24 months or to death. Water samples were collected from the homes of patients and from the environment and cultured for organisms of the Myobacterium avium complex (MAC). Environmental and clinical isolates were compared using pulsed field gel electrophoresis (PFGE). RESULTS: NTM infection occurred in 22 (43%) of 51, 19 isolates were Mycobacterium avium, two M. genavense and one M. intracellulare. Multivariate analysis identified urban residence (P=0.04) and eating raw fish (P=0.04) as independent risk factors. Molecular analysis revealed two clusters of related isolates (three M. avium, two M. genavense) among urban residents. CONCLUSION: AIDS patients in Finland have high rates of disseminated infection due to NTM. Clusters of identical organisms and association with urban residence suggests that these are newly acquired infections in advanced AIDS.

The risks and benefits of childhood bacille Calmette-Guérin immunization among adults with AIDS. International MAC study groups.

OBJECTIVE: To define the risks of disseminated bacille Calmette-Guérin (BCG) or disseminated Mycobacterium tuberculosis in adults with AIDS who were immunized with BCG in childhood. DESIGN: HIV-infected patients with CD4 < 200 x 10(6)/l were enrolled from five study sites (New Hampshire, Boston, Finland, Trinidad and Kenya). Prior BCG immunization was determined and blood cultures for mycobacteria were obtained at study entry and at 6 months. Acid-fast bacilli were identified as Mycobacterium tuberculosis complex (MTBC) using DNA probes. MTBC isolates were then typed by both IS6110 restriction fragment length polymorphism and polymerase chain reaction/restriction enzyme analysis. SETTING: Most patients in New Hampshire and Finland were outpatients; most patients in Trinidad were inpatients with terminal illness; and most patients in Kenya were outpatients, although 44 were inpatients with terminal illness. PARTICIPANTS: A total of 566 patients were enrolled, including 155 with childhood BCG immunization; 318 patients had a single study visit and culture, and 248 patients had two study visits and cultures. MAIN OUTCOME MEASURES: Isolation and identification of mycobacteria from blood cultures. RESULTS: Blood cultures were positive for MTBC in 21 patients; none were positive for M. bovis BCG, and 21 were M. tuberculosis-positive. In Trinidad, seven (87%) out of eight isolates of M. tuberculosis were indistinguishable by IS6110 typing; BCG immunization was associated with a decreased risk of bacteremic infection with M. tuberculosis (P = 0.05). CONCLUSIONS: The risk of disseminated BCG among adult AIDS patients with childhood BCG immunization is very low. Childhood BCG immunization is associated with protection against bacteremia with M. tuberculosis among adults with advanced AIDS in Trinidad.

The international epidemiology of disseminated Mycobacterium avium complex infection in AIDS. International MAC Study Group.

OBJECTIVE: To determine rates of disseminated Mycobacterium avium complex (MAC) infection among AIDS patients in developed and developing countries, and to determine whether different rates reflect differences in exposure or immunity, or both. DESIGN: Prospective cohort study. SETTING: University hospitals and outpatient AIDS programs. METHODS: HIV-infected subjects with CD4 counts < 200 x 10(6)/l were interviewed and had CD4 lymphocyte counts, blood cultures for mycobacteria (baseline and at 6 months), and skin tests with purified protein derivative (PPD) and M. avium sensitin. RESULTS: Among 566 study patients rates of disseminated MAC were 10.5-21.6% in New Hampshire, Boston and Finland compared to 2.4-2.6% in Trinidad and Kenya (P < 0.001). PPD skin test reactions > or = 5 mm were present in 20% of patients from Kenya compared to 1% at other sites (P < 0.001). Among patients from the United States and Finland, multiple logistic regression indicated that occupational exposure to soil and water was associated with a decreased risk of disseminated MAC, whereas the following were associated with an increased risk of disseminated MAC: low CD4 count, swimming in an indoor pool, history of bronchoscopy, regular consumption of raw or partially cooked fish/shellfish and treatment with granulocyte colony-stimulating factor. CONCLUSIONS: Rates of disseminated MAC in AIDS are higher in developed than developing countries and are due to both differences in exposure and differences in immunity. These data provide a rationale for prevention of MAC through both active immunization and reduction in exposure to the organism.