Doubling of the tuberculosis incidence in Greenland over an 8-year period (1990-1997).

OBJECTIVE: To determine the trends in conventional and molecular epidemiology of tuberculosis (TB) in Greenland over an 8-year period. DESIGN: A nation-wide, retrospective, population-based study of all cases of TB reported to the National Health Division of Greenland from 1 January 1990 to 31 December 1997. An analysis of microbiology data including RFLP results. RESULTS: The annual incidence increased from 85/100,000 in 1990 to 172/100,000 in 1997; 335 (72%) of the cases were culture-positive. On average 58% of culture-positive cases were smear-positive, with an increase from 40% in 1990 to 69% in 1997. There was a significant increase in childhood TB from four cases in 1990 to 26 in 1997. RFLP analysis shows that 15% of the patients were infected with unique strains and 85% were infected with strains belonging to one of 20 clusters. There were four major clusters, comprising respectively 52, 34, 26 and 14 patients. CONCLUSION: There was a dramatic increase in TB cases in Greenland from 1990 to 1997. The increase is due to micro-epidemics in small isolated settlements, and affects primarily young adults and children. RFLP analysis confirms this observation and indicates confined, local transmission. In this context RFLP is not useful as the only parameter for monitoring recent transmission.

Humoral response to Mycobacterium tuberculosis-specific antigens in African tuberculosis patients with high prevalence of human immunodeficiency virus infection.

SETTING: The applicability of serodiagnosis of tuberculosis using Mycobacterium tuberculosis-complex-specific antigens in a Tanzanian population with high prevalence of HIV. OBJECTIVE: This study was performed to evaluate the usefulness, sensitivity and specificity of serology using M. tuberculosis-specific antigens in the diagnosis of tuberculosis in patients with and without HIV co-infection. DESIGN: Patients with proven pulmonary and extrapulmonary tuberculosis at a major referral centre in Tanzania were enrolled in the study. The control group consisted of patients without a history of previous tuberculosis admitted to the trauma ward and of healthy volunteers. Sera were analysed by an enzyme linked immunoassay (ELISA) using two M. tuberculosis specific proteins as antigen: the 38 kDa protein [3T] and a 17 kDa protein. In addition was recorded presence or absence of BCG scar and tuberculin sensitivity and the sera were tested for HIV and analysed for beta-2-microglobulin content. RESULT: Sensitivity and specificity were markedly reduced in tuberculosis patients with HIV co-infection compared to patients without this disease (73% and 70% versus 52% and 50% respectively). CONCLUSION: Serology for diagnosis of tuberculosis is not feasible in an HIV endemic region.

Serovars of Mycobacterium avium complex isolated from patients in Denmark.

Danish isolates of Mycobacterium avium complex were serotyped by the use of seroagglutination. The most prevalent serovars among patients with AIDS (n = 89) were 4 and 6, while among non-AIDS patients the most prevalent serovars were 1, 6, and 4, with no major differences between those in patients with pulmonary disease (n = 65) and those in patients with lymph node infection (n = 58). The results suggest a Scandinavian distribution of serovars with a predominance of serovar 6 and fail to demonstrate any selective protection against different serovars by Mycobacterium bovis BCG vaccination.

Hepatitis A vaccine. A new convenient single-dose schedule with booster when long-term immunization is warranted.

A total of 162 anti-HAV-negative healthy adults were immunized with a single high dose (1440 ELISA units = 1 ml) of inactivated hepatitis A vaccine and a booster was given at month 6. Antibodies were measured after modification of a commercial ELISA kit, enabling quantification of titres down to 6 mIU ml-1. After 14 days, 96% of vaccinees had positive anti-HAV titres (> 20 mIU ml-1), and after 30 days all vaccinees had seroconverted. The geometric mean titres were 150 mIU ml-1 and 380 mIU ml-1 respectively. The booster dose at month 6 elicited a dramatic (25-fold) increase in antibody titres from 125 to 3090 mIU ml-1. Thus a single dose may be a convenient alternative to immunoglobulin for inducing rapid seroprotection, with a booster dose at month 6 ensuring long-lasting protection.

Polymerase chain reaction for detection of Mycobacterium tuberculosis in sputum.

The polymerase chain reaction (PCR) was evaluated in a trial which, with respect to the positive-to-negative ratio, approximated the situation of a diagnostic laboratory in a tuberculosis-endemic area. Three hundred sputum samples were included in the study, of which one-third were known to contain mycobacteria as judged by direct microscopy. The repetitive insertion sequence IS6110/IS986 of Mycobacterium tuberculosis was used as a target. The samples were spiked with DNA from a modified IS6110/IS986 sequence, which gives rise to PCR products easily distinguished from PCR products amplified from chromosomal Mycobacterium tuberculosis DNA. This allowed identification of samples that contained substances inhibitory to the Taq polymerase. The detection limit of the assay was 0.05 pg to 0.5 pg of purified Mycobacterium tuberculosis DNA, corresponding to 10 to 100 organisms. The sensitivity and specificity of the PCR was compared with that of conventional microscopy and culture. It was concluded that this method is fast and sensitive, but that culture currently is crucial for assessing viability and thus infectivity.

Infection with Mycobacterium bovis in a patient with AIDS: a late complication of BCG vaccination.

We present a 28-year-old HIV-infected man with a 2-year delayed complication of BCG immunization. When immunized the man was healthy, with an unknown HIV status, but 2 years later he was diagnosed with AIDS because of a Pneumocystis carinii pneumonia. He was successfully treated and discharged in a state of good health. A few months later he presented with an enlarged lymph node and Mycobacterium bovis, BCG strain, was cultured. No sign of dissemination was found. We discuss the indications for BCG vaccination in adults, especially in areas and in populations with a high prevalence of HIV.

[The worldwide AIDS epidemic and the role of Danida in the international control work]. / Den globale AIDS-epidemi og Danida's rolle i det internationale kontrolarbejde.

The global AIDS epidemic already influences health planning and distribution of resources to a great extent in the health sectors of many countries, particularly in the third world. AIDS will influence health development markedly among certain population groups in many of the countries with whom Danida works and the socio-economical and demographic consequences of the epidemic influence planning of health assistance by Danida to a great extent. This article presents a brief review of the pattern of the global epidemic and a description of the present extent of the AIDS epidemic and tendency to develop. Some of the most important effects of the epidemic in Africa south of Sahara are described and it is documented that the individual countries affected by AIDS in Africa will experience very considerable direct and indirect expenses resulting from the epidemic. At the turn of the year 1989-1990, approximately 200,000 orphans of AIDS victims were present in Africa south of Sahara and this number will increase to approximately 500,000 by the end of 1992. This and other effects of the AIDS epidemic confront the individual countries with entirely new problems which require new and unorthodox strategies in health planning. Specific medical aspects of the HIV epidemic in developing countries are discussed together with the roles of WHO, Danida and the voluntary Danish organisations in global AIDS control. An obvious risk exists that a new programme for disease control which has access to relatively great resources will establish a new vertical structure both internationally and in the individual countries.(ABSTRACT TRUNCATED AT 250 WORDS)