AIDS epidemiology: the past ten years, the next ten years.

PIP: This article assesses the current seroprevalence of HIV worldwide, examines the patterns of infection over the past 10 years, and discusses the future impact of HIV. According to the World Health Organization (WHO), 8 million people have become infected with HIV since the early 1980s. As of November 1990, WHO estimates that some 800,000 people have developed AIDS. 54% of the HIV infections have occurred in Africa, 35% in the Americas, and 8% in Western Europe. The main HIV transmission routes are: 1) sexual intercourse with an infected partner (accounting for 75% of all infections); 2) HIV-infected blood or blood products, which include blood transfusions (5%), IV drug use (10%), and other needle (0.1%); and 3) perinatal transmission from infected mother to infant (10%). The article describes the 3 patterns of HIV infection so far: 1) In industrialized countries and in Latin America, HIV infections appeared in the early 1980s among homosexual men or IV drug users and then spread to the heterosexual population; 2) In Eastern and Central Africa, where heterosexual sex has been the main transmission route, infections began in the late 1970s; 3) In the rest of the world, HIV was not introduced until the mid-1980s, and because of the low prevalence rate, the main transmission route has not yet been determined. By the year 2000, WHO expects some 15-20 million HIV infections among adults and some 5-6 million AIDS cases among adults. In some industrialized countries, AIDS could become the leading cause of death among 20-40 year olds during the 1990s. At the same time, AIDS will have a devastating effect on sub-Saharan Africa's urban population, which will see a great increase in child mortality rates and in the number of orphaned children.^ieng

Behaviour of different clinical, immunological and serological parameters observed in a group of HIV positive patients during a 12 month treatment period with zidovudine.

During a 12 month open clinical trial, 14 patients (6 with AIDS, 2 with ARC and 6 with PGL) were continuously administered a daily 1200 mg dose of Zidovudine. Clinical course was correlated with a number of serological (HIV p24 antigen, p17 and p24 antibodies) and immunological (CD4 cell counts, serum neopterin and beta 2-microglobulin levels) parameters. All patients survived until the end of the trial: none developed major opportunistic infections, but 5 required an average of 7 blood transfusions each. Disappearance of p24 Ag was observed in 4 out of 7 patients, although with a subsequent reappearance in 3; moreover, changes of p24 Ag and HIV core Ab profiles were generally paralleled by neopterin and, to a lesser extent, by CD4/neopterin ratio variations. In the long run, significant differences between baseline and end-point results were shown by neopterin, but not by CD4 cell counts and beta 2-microglobulin levels. Efficacy of Zidovudine therapy seemed to be mainly related to clinical, but even more so, to immunological and serological status at baseline; in fact, severe clinical deterioration was observed in 2 patients who had an already low CD4/neopterin ratio from the beginning, coupled with a p24 Ag positivity and a negativity of both anti-p17 and -p24. Conversely, a stable clinical condition was observed in those patients in whom the reverse was true.

CD4+:neopterin ratio correlates with p24 antigenaemia in HIV infected patients.

In an effort to improve the Walter Reed Staging System (WR), which mainly relies on immune depletion parameters, by introducing viral replication and T-cell activation markers, we examined by p24 antigenaemia and serum neopterin levels (SNL) 72 HIV positive PGL, ARC and AIDS patients (11 of whom classified as WR 2, 21 as WR 3, 16 as WR 5 and 24 as WR 6). While CD4 cell counts, already weakly correlating with the WR itself, did not significantly differ between p24 antigen (p24 AG) positive and negative patients, striking differences between the two groups, especially in PGL patients (p less than 0.0001), were found as far as SNL was concerned. In fact, SNL values, fluctuating around 10 and 30 nmol/l, respectively, in p24 Ag positive and negative patients regardless of their WR allocation, seemed rather to reflect, as global means of any given class, prevalence rate of p24 Ag positivity. We suggest, therefore, to use CD4/SNL ratio (R) for HIV infection and disease staging, as it not only may represent a compromise index between cellular immune depletion and T-cell activation, but also seems to take into account the viral replication component, already shown to be an important predictive marker of disease progression.

Thiamphenicol in the treatment of chancroid in men.

Fifty-five men were treated for culture-positive chancroid with two 2.5-g doses of thiamphenicol given on each of two consecutive days. Forty-nine patients (89.1%) were cured on this regimen. No adverse effects were noted. Cultured strains of Haemophilus ducreyi were found to be sensitive to thiamphenicol.

The aetiology of acute hepatitis in Zimbabwe.

The cause of acute viral hepatitis in 141 patients admitted to both Infectious Diseases Hospitals in Harare (Zimbabwe) was hepatitis A in 44, hepatitis B in 86 and hepatitis Non-A Non-B in 11. The wide distribution of hepatitis A and B viruses and early exposure to both in Zimbabwe are shown by the high positivity rate for anti-HAV antibody in patients under 10 years old (87.5%) and for anti-HBs antibody in patients over 20 (60%). Among the 86 hepatitis B cases, e and delta systems were also investigated: 66 patients (76.5%) were HBeAg positive, six (7%) anti-HBe positive and 14 (16.5%) negative for both; only one was anti-delta positive. Two cases of fulminant liver failure (both occurring in HBsAg and anti-HBc IgM positive, but delta-markers negative patients) and five cases of hepatoma (only one of whom was negative for all HBV markers) are described.