Serum samples of 120 patients in different stages of chronic human immunodeficiency virus type 1 (HIV-1) infection, 11 patients with primary HIV-1 infection (PHI), and 49 HIV-1 seronegative homosexual men were analyzed for tumor necrosis factor-alpha (TNF-alpha), interferon-alpha (IFN-alpha), and HIV-1 p24 antigen. Increased levels of IFN-alpha and TNF-alpha were found in some, but not all, cases with PHI. During progressing disease IFN-alpha occurred in serum with increasing frequency and concentration. Raised levels of TNF-alpha were found in all stages of chronic infection, but were less common in patients with AIDS than were raised levels of IFN-alpha. The levels of the two substances were not correlated. There was a correlation between IFN-alpha, but not TNF-alpha, and the occurrence of HIV-1 p24 antigen in serum. These results suggest that IFN-alpha and TNF-alpha are induced by different agents during HIV-1 infection. The findings would be consistent with the hypothesis that IFN-alpha and TNF-alpha are counteracting forces that have important down- and upregulatory effects, respectively, on HIV-1 replication in vivo.

Many tests for HIV or HIV antibody can now be employed for an early confirmation of primary HIV infection (PHI). Currently available screening tests proved much more sensitive than older tests, and seroconversion was usually detected within one month after infection. Consequently, in Sweden we now recommend only 3 months of follow-up after most cases of HIV exposure.

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Human immunodeficiency virus (HIV) has been isolated from plasma in 6 of 7 patients showing clinical symptoms of a primary HIV infection. Parallel cultures from peripheral blood mononuclear cells (PBMC) yielded virus in 5 patients. In one case, virus could only be isolated from the cerebrospinal fluid but not from peripheral blood. Detectable viremia was transient and preceded the appearance of HIV specific antibodies. After cessation of acute symptoms, the frequency of HIV isolations was similar to that of asymptomatic carriers (23 and 26%, respectively). The role of the immune response in terminating detectable viremia remains to be established.

Serial blood samples were obtained from 21 homosexuals who had developed symptomatic primary infection with human immunodeficiency virus (HIV) after a median incubation time of 14 days. During the first two weeks after the onset of illness HIV antigen (p24) was detected in the blood by enzyme linked immunosorbent assay (ELISA). During the second and third weeks after the onset of illness p24 antibody was detected by Western blot assay and antigen concentrations rapidly decreased to undetectable values. Dissociation of antigen-antibody complexes showed complexed antigen during the phase of declining concentrations of free antigen. Neither free nor complexed antigen was detected in any serum samples for several months thereafter, which suggested that failure to detect HIV antigen reflected low or absent synthesis of viral protein rather than masking of antigen by antibodies. Reappearance of HIV antigen with a fall in p24 antibody concentration was observed in a few patients six months or more after the onset of disease.The combined use of antigen and antibody assays made it possible to obtain evidence of infection with HIV in all of the 95 serum samples tested, illustrating the usefulness of these assays for diagnosing infection with HIV in its early stages.

The clinical symptoms and signs were assessed in 20 consecutive patients developing infection with the human immunodeficiency virus (HIV). All were male homosexuals and all presented with a glandularfever-like illness. Changes in laboratory values were compared with findings in 40 HIV negative male homosexual controls.In the 10 patients for whom date of exposure to the virus could be established the incubation period was 11-28 days (median 14). One or two days after the sudden onset of fever patients developed sore

In an open controlled study 286 health care workers in Stockholm, Sweden, received 20 micrograms of a recombinant hepatitis B vaccine (Engerix B) by the intramuscular route, and 383 2 micrograms by the intradermal route. Seroconversion to protective anti-HBs levels (anti-HBs titre greater than or equal to 10 IU/l) was achieved in 94% of the i.m. and 89% of the i.d. vaccinees. Female sex, intramuscular vaccination, young age, and being a non-smoker were associated with a higher response rate and a higher geometric mean anti-HBs titre than male sex, intradermal vaccination, old age and being a smoker. If an acceptable response rate to protective anti-HBs levels of 85% is chosen, intradermal vaccination can be used as a cost reducing strategy for all women and for non-smoking men less than 30 years of age, as estimated in a logistic regression model. Due to the variable antibody response in different individuals, post vaccination testing for anti-HBs titres is recommended in health care workers, regardless of vaccination route.

The aim of this study was to make a population‐based estimate of the risk of hospitalization and complications during virologically confirmed respiratory syncytial virus (RSV) infection in relation to established risk factors, and an estimation of additional risk factors and outcome as seen in a tertiary care referral centre. During a period of 12 y, all children with virologically confirmed RSV infection were included. Recorded complications were: admission to the intensive care unit, mechanical ventilation, death and later hospitalization for wheezing. In total, 1503 cases were identified, 1354 of which originated from the population defined by the catchment area. There was a biannual seasonal variation with late small outbreaks alternating with early large ones. The hospitalization rates for infants without risk factors were 0.8 and 1.4% during the 2 epidemic types. They were 1.6–3.2% for infants born preterm (>33 gestational wk), 2.9–7.0% for children under 2 y old with chronic lung disease of prematurity and 2.8–6.4% for infants with congenital heart disease. The presence of siblings in the family more than doubled the risk of hospitalization. Later hospitalization for wheezing occurred in 8.4 and 4.9% of children without risk factors over and under the age of 2 mo, respectively (p > 0.001). Conclusion: This study found lower population rates of hospitalization and complications than have previously been reported. The seasonal variation and the presence of siblings in the home influenced these rates by factors of 2.