High sensitivity for tuberculosis in a national integrated surveillance system in Finland.

Little is known about the sensitivity of surveillance for tuberculosis after integration of formerly dedicated tuberculosis surveillance and control into the general health care system, an integration which took place in Finland in 1987. We compared routine laboratory notifications to the National Infectious Disease Register (NIDR) for Mycobacterium tuberculosis from January 1, 1995, to December 31, 1996, with data collected independently from all laboratories offering M. tuberculosis culture, and with data from patient records. 1059 culture-positive cases were found. The overall sensitivity of the NIDR was 93 % (984/1059). The positive predictive value of a culture-positive case in the NIDR to be a true culture-confirmed case was 99%. For the culture-confirmed cases in the NIDR, one or more physician notification forms had been submitted for 89%. A highly sensitive notification system for culture-positive tuberculosis can be achieved in an integrated national infectious disease surveillance system based on laboratory notification.

High sensitivity for tuberculosis in a national integrated surveillance system in Finland.

Little is known about the sensitivity of surveillance for tuberculosis after integration of formerly dedicated tuberculosis surveillance and control into the general health care system, an integration which took place in Finland in 1987. We compared routine laboratory notifications to the National Infectious Disease Register (NIDR) for Mycobacterium tuberculosis from January 1, 1995, to December 31, 1996, with data collected independently from all laboratories offering M. tuberculosis culture, and with data from patient records. 1059 culture-positive cases were found. The overall sensitivity of the NIDR was 93 % (984/1059). The positive predictive value of a culture-positive case in the NIDR to be a true culture-confirmed case was 99%. For the culture-confirmed cases in the NIDR, one or more physician notification forms had been submitted for 89%. A highly sensitive notification system for culture-positive tuberculosis can be achieved in an integrated national infectious disease surveillance system based on laboratory notification.

Mild iron overload in patients carrying the HFE S65C gene mutation: a retrospective study in patients with suspected iron overload and healthy controls.

BACKGROUND AND AIMS: The role of the HFE S65C mutation in the development of hepatic iron overload is unknown. The aim of the present study was: (A) to determine the HFE S65C frequency in a Northern European population; and (B) to evaluate whether the presence of the HFE S65C mutation would result in a significant hepatic iron overload. PATIENTS AND METHODS: Biochemical iron parameters and HFE mutation analysis (for the C282Y, H63D, and S65C mutations) were analysed in 250 healthy control subjects and collected retrospectively in 296 patients with suspected iron overload (elevated serum ferritin and/or transferrin saturation). The frequency of patients having at least mild iron overload, and mean serum ferritin and transferrin saturation values were calculated for each HFE genotype. For patients carrying the S65C mutation, clinical data, liver biopsy results, and amount of blood removed at phlebotomy were determined. RESULTS: The HFE S65C mutation was found in 14 patients and eight controls. In controls, the S65C allele frequency was 1.6%. The S65C allele frequency was enriched in non-C282Y non-H63D chromosomes from patients (4.9%) compared with controls (1.9%) (p<0.05). Serum ferritin was significantly increased in controls carrying the S65C mutation compared with those without HFE mutations. Fifty per cent of controls and relatives having the S65C mutation had elevated serum ferritin levels or transferrin saturation. The number of iron overloaded patients was significantly higher among those having HFE S65C compared with those without any HFE mutation. Half of patients carrying the S65C mutation (7/14) had evidence of mild or moderate hepatic iron overload but no signs of extensive fibrosis in liver biopsies. Screening of relatives revealed one S65C homozygote who had no signs of iron overload. Compound heterozygosity with S65C and C282Y or H63D did not significantly increase the risk of iron overload compared with S65C heterozygosity alone. CONCLUSIONS: The HFE S65C mutation may lead to mild to moderate hepatic iron overload but neither clinically manifest haemochromatosis nor iron associated extensive liver fibrosis was encountered in any of the patients carrying this mutation.

Analysis of HIV-1 genetic subtypes in Finland reveals good correlation between molecular and epidemiological data.

The molecular epidemiology of HIV-1 genetic subtypes was studied in a cross-sectional sample collected from HIV-infected individuals living in Finland between 1988 and 1994 and compared with independently collected epidemiological data. Subtypes were determined by sequencing and phylogenetic analysis of the gag NCp7 and the env coding regions of PBMC provirus. Finnish viruses belonging to 7 subtypes were found. Two thirds (n = 70) of the sequences could be classified as subtype B, while others belonged to subtypes A, C, D, F and G and the circulating recombinant form AE(CM240) (n = 25). There were significant differences in gender distribution and mode-of-transmission between B-type infections and infections with the other subtypes. Most subtype B strains in Finland were associated with homosexual transmission and about half of these were acquired in Finland, while most individuals harbouring non-B infections indicated heterosexual transmission and direct or indirect contact with Africa or Southeast Asia. The heterogeneity of genetic subtypes in the country was in good agreement with the epidemiological data suggesting that a significant proportion of infections were imported. HIV-1 subtype determination may prove to be a valuable tool for providing objective epidemiological data.

HIV antibodies in whole saliva detected by ELISA and western blot assays.

Paired serum and saliva samples were tested by enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) for the presence of human immunodeficiency virus (HIV) antibodies. The study group included 36 individuals known to be HIV seropositive and 14 healthy, seronegative controls. HIV antibodies were detected in all but one of the saliva samples of the seropositive subjects. In this particular patient, seroconversion was documented 1 week earlier by sequential testings. A further saliva sample obtained 2 months later was ELISA positive for salivary HIV antibodies. Antibodies against HIV proteins gp120 and gp160 were detected by Western blot assay in all saliva specimens taken from HIV seropositive subjects (including the ELISA-negative patient who seroconverted. Antibodies against other viral proteins (p65, p55, p51, gp41, p35, p24 p18) were found in saliva haphazardly without any clear-cut correlation with the clinical stage of the disease. Pretreatment of the saliva with protease inhibitor was essential for the diagnostic use of saliva for the detection of HIV antibodies by Western blot assay. Calculation of the ratio of titres in serum to those in saliva showed the highest ratios in symptomless subjects (mean +/- SD; 1844 +/- 1412) and the lowest in patients with acquired immune deficiency syndrome (AIDS) (mean +/- SD; 811 +/- 445). The ratio of serum to saliva by ELISA showed a positive correlation with salivary flow rate, indicating a dilution of salivary HIV antibodies with increasing salivary flow rate. The gingival bleeding index was negatively correlated with the ratio, supporting the concept that salivary HIV antibodies transudate from blood to saliva via gingival fluid.