Immune thrombocytopenic purpura might be an early hematologic manifestation of undiagnosed human immunodeficiency virus infection.

Little research focuses on the association between immune thrombocytopenic purpura and human immunodeficiency virus infection in Taiwan. This study investigated whether immune thrombocytopenic purpura might be an early hematologic manifestation of undiagnosed human immunodeficiency virus infection in Taiwan. We conducted a retrospective population-based cohort study using data of individuals enrolled in Taiwan National Health Insurance Program. There were 5472 subjects aged 1-84 years with a new diagnosis of immune thrombocytopenic purpura as the purpura group since 1998-2010 and 21,887 sex-matched and age-matched, randomly selected subjects without immune thrombocytopenic purpura as the non-purpura group. The incidence of human immunodeficiency virus infection at the end of 2011 was measured in both groups. We used the multivariable Cox proportional hazards regression model to measure the hazard ratio and 95 % confidence interval (CI) for the association between immune thrombocytopenic purpura and human immunodeficiency virus infection. The overall incidence of human immunodeficiency virus infection was 6.47-fold higher in the purpura group than that in the non-purpura group (3.78 vs. 0.58 per 10,000 person-years, 95 % CI 5.83-7.18). After controlling for potential confounding factors, the adjusted HR of human immunodeficiency virus infection was 6.3 (95 % CI 2.58-15.4) for the purpura group, as compared with the non-purpura group. We conclude that individuals with immune thrombocytopenic purpura are 6.47-fold more likely to have human immunodeficiency virus infection than those without immune thrombocytopenic purpura. We suggest not all patients, but only those who have risk factors for human immunodeficiency virus infection should receive testing for undiagnosed human immunodeficiency virus infection when they develop immune thrombocytopenic purpura.

Clinical predictors for the aetiology of peripheral lymphadenopathy in HIV-infected adults.

OBJECTIVES: The aim of the study was to determine the aetiology and clinical predictors of peripheral lymphadenopathy in HIV-infected individuals during the antiretroviral (ARV) era in a nontuberculosis endemic setting. METHODS: A multicentred, retrospective cohort study of peripheral lymph node biopsies in HIV-positive adults was carried out. A total of 107 charts were identified and reviewed for clinical features, lymphadenopathy size, and ARV use and duration. Biopsy results were categorized, and multivariate logistic regression determined independent predictors of lymphadenopathy aetiology. RESULTS: Evaluation of 107 peripheral lymph node biopsies revealed that 42.9% of peripheral lymphadenopathy was attributable to malignancy, 49.5% to reactive changes, and 7.5% to infections, with only 2.8% of all cases secondary to tuberculosis. Fevers, weight loss, ARV use, and lower viral loads are significantly associated with nonreactive lymphadenopathy. CONCLUSIONS: Lymphadenopathy is likely to be reactive or malignant in nontuberculosis endemic regions. Readily available clinical features can aid clinicians in predicting the underlying aetiology, those at risk for malignancy, and who to biopsy.

Surgical practice in a maximum security prison - unique and perplexing problems.

The practice of general surgery in a prison population differs considerably from that in a general surgical practice. We audited surgical consultations at the Mangaung Correctional Centre from December 2003 to April 2009. We found a high incidence of foreign object ingestion and anal pathology. Understanding the medical and social aspects of prison life facilitates the treatment of inmates with surgical problems.

The changing face of HIV/AIDS in treated patients.

The spectrum of complications emerging in successfully treated HIV-infected patients has dramatically changed since the advent of HAART. Typical AIDS-defining illnesses have been substituted by new comorbid conditions that threaten even those patients who maintain virologic suppression. Proper management of cardiovascular risk, and early diagnosis of AIDS-related and, particularly, non-AIDS-related malignancies (including papilomavirus-related neoplasms) must be introduced into the routine of care. Hot areas of investigation include HIV-associated neurocognitive disorders, hepatitis B and C coinfection, non-alcoholic fatty liver disease, progressive multifocal leukoencephalopathy and tuberculosis. Bone and kidney long-term toxicities and lipoatrophy remain as issues of paramount importance. The identification and early treatment of immune reconstitution disease is also of major interest, specially in those patients starting their antiretroviral treatment with severe CD4 cell depletion. The present review focuses on these twelve areas of increasing interest for physicians currently facing successfully treated HIV+ patients.

[Prevalence of neurological complications in Japanese patients with AIDS after the introduction of HAART].

We investigated trends in neurological complications of infection with human immunodeficiency virus (HIV) in Japan after the introduction of highly active antiretroviral therapy (HAART). Two questionnaire surveys were performed in hospitals treating acquired immunodeficiency syndrome (AIDS) to compare two periods: immediately after the introduction of HAART (1999-2001); and a few years later (2002-3). Neurological complications accompanied 15.9% in 1999-2001 and 9.8% in 2002-3. Neurological complications developed without HAART in about 80% of cases. Neurological complications developed as the first AIDS-defining disease for 8.3% of AIDS patients in 1999-2001 and for 5.4% in 2002-3. Prevalences of HIV encephalopathy and myelopathy decreased markedly over the study period, as reported in other developed nations. However, prevalences of cytomegalovirus encephalitis, PML and primary brain lymphoma did not decrease. PML and primary brain lymphoma occurred in patients who received HAART and whose CD4 counts were relatively high during the study period. This is probably related to the extended survival of HIV-infected individuals after the introduction of HAART as a worldwide therapy, and the reactivation of viremia or latent infection persisting within the central nervous system.

[Clinical and laboratory characteristics of HIV-infection in servicemen].

HIV-infection in Russia and its Armed Forces is a serious threat to the national health and country's safety. Study of peculiarities of disease spread in the military collectives and HIV-infection manifestation is an actual problem. HIV-infection is diagnosed during the latent stage in all categories of servicemen and characterized by unchanged function of cellular and humoral immunity. In most servicemen with HIV-infection the disease course has a form of co-infection with parenteral hepatitis B and C.

Long-term clinical benefit after highly active antiretroviral therapy in advanced HIV-1 infection, even in patients without immune reconstitution.

Our objective was to assess, in the clinical setting, the predictors of immune reconstitution (IR) and its relation with long-term clinical benefit, in HIV patients with advanced disease after highly active antiretroviral therapy (HAART) through an observational study. A retrospective cohort study in a clinical setting of 383 consecutive adult patients with advanced HIV infection (CD4+ cells <200/mm(3) at baseline), starting their first protease inhibitor (PI)-containing regimen was observed. Immune reconstitution was defined as CD4 count >200 cells/mm(3) and an increase > or =100 cells from baseline, anytime since starting HAART. Clinical benefit was defined as decreased mortality and reduction in AIDS-defining events, AIDS-related complex (ARC) events, major infections and hospitalization (days spent in hospital). During a mean follow-up of 808 days, 261 patients (68.1%) achieved IR. About 50% of these patients reached this result within one year after starting HAART. In multivariate analysis, predictors of immune recovery were sex (female) and baseline CD4 count higher than 50 cells/mm(3). The group of patients with IR had greater clinical benefit with lower mortality, fewer AIDS-defining events, shorter lengths of stay in hospital, fewer ARC events and fewer major infections during all the follow-up (P < 0.0001, tests for trends). However, although they did less remarkably than the first group of patients, even those patients who did not achieve IR experienced a significant decrease in the incidence of all the above events, as compared with the first and sometimes the second trimester after starting their HIV therapy. About 70% of HIV patients with advanced disease achieved IR after starting HAART. Such a benefit is a time-dependent effect and may even take more than 2 years to occur. Predictors of IR were sex (female) and higher baseline CD4 count (>50 cells/mm(3)). The patients who achieved immune recovery performed clinically better than patients who did not. Also the patients who failed to gain such a strong immunological recovery experienced a long-term clinical benefit. This suggests that PI-containing regimens, in advanced HIV disease, may produce a significant clinical benefit, at least temporary, even for patients who do not achieve a substantial immune response.

Tuberculosis in a prison population in Mwanza, Tanzania (1994-1997).

SETTING: Bugando Medical Centre, a referral consultant hospital in the lake zone to which all inmates from Butimba prison are admitted and treated. OBJECTIVE: To determine the extent of open (smear-positive) tuberculosis and other types of tuberculosis among prisoners with tuberculosis. DESIGN: A retrospective cohort study. Case notes of 501 prisoners from January 1994 to December 1997 were retrieved and reviewed. RESULTS: The proportion of open tuberculosis in this study was high, with 204 prisoners (40.7%) having smear-positive tuberculosis. Co-infection was recorded in the majority of patients; HIV/AIDS was recorded in 25.9% of cases. The mean length of imprisonment at the time of diagnosis was 19 months. CONCLUSION: The proportion of open, smear-positive tuberculosis among prisoners admitted with tuberculosis is high. Intervention measures specifically targeting this population are urgently needed in order to contain tuberculosis disease in the prison population.

Risk factors for tuberculosis among human immunodeficiency virus-infected persons. A case-control study in Belo Horizonte, Minas Gerais, Brazil (1985-1996).

The objective of this study was to identify tuberculosis risk factors and possible surrogate markers among human immunodeficiency virus (HIV)-infected persons. A retrospective case-control study was carried out at the HIV outpatient clinic of the Universidade Federal de Minas Gerais in Belo Horizonte. We reviewed the demographic, social-economical and medical data of 477 HIV-infected individuals evaluated from 1985 to 1996. The variables were submitted to an univariate and stratified analysis. Aids related complex (ARC), past history of pneumonia, past history of hospitalization, CD4 count and no antiretroviral use were identified as possible effect modifiers and confounding variables, and were submitted to logistic regression analysis by the stepwise method. ARC had an odds ratio (OR) of 3.5 (CI 95% - 1.2-10.8) for tuberculosis development. Past history of pneumonia (OR 1.7 - CI 95% 0.6-5.2) and the CD4 count (OR 0.4 - CI 0. 2-1.2) had no statistical significance. These results show that ARC is an important clinical surrogate for tuberculosis in HIV-infected patients. Despite the need of confirmation in future studies, these results suggest that the ideal moment for tuberculosis chemoprophylaxis could be previous to the introduction of antiretroviral treatment or even just after the diagnosis of HIV infection.

Risk Factors for tuberculosis among human immunodeficiency virus-infected persons. A case-control study in Belo Horizonte, Minas Gerais, Brazil (1985-1996)

The objective of this study was to identify tuberculosis risk factors and possible surrogate markers among human immunodeficiency virus (HIV)-infected persons. A retrospective case-control study was carried out at the HIV outpatient clinic of the Universidade Federal de Minas Gerais in Belo Horizonte. We reviewed the demographic, social-economical and medical data of 477 HIV-infected individuals evaluated from 1985 to 1996. The variables were submitted to an univariate and stratified analysis. Aids related complex (ARC), past history of pneumonia, past history of hospitalization, CD4 count and no antiretroviral use were identified as possible effect modifiers and confounding variables, and were submitted to logistic regression analysis by the stepwise method. ARC had an odds ratio (OR) of 3.5 (CI 95 per cent - 1.2-10.8) for tuberculosis development. Past history of pneumonia (OR 1.7 - CI 95 0.6-5.2) and the CD4 count (OR 0.4 - CI 0.2-1.2) had no statistical significance. These results show that ARC is an important clinical surrogate for tuberculosis in HIV-infected patients. Despite the need of confirmation in future studies, these results suggest that the ideal moment for tuberculosis chemoprophylaxis could be previous to the introduction of antiretroviral treatment or even just after the diagnosis of HIV infection.

Genetic subtypes of HIV type 1 in Republic of Congo.

To assess the molecular epidemiology of HIV-1 in Republic of Congo (Congo), we investigated 29 HIV-1s obtained from 82 Congolese AIDS and ARC patients in 1996 and 1997. Part of the env region including the V3 loop was phylogenetically analyzed. The genotypes observed were varied: of 29 specimens, 12 (41 %) were subtype A, 1 (3%) was subtype D, 6 (21%) were subtype G, 6 (21%) were subtype H, 2 (7%) were subtype J, and 2 (7%) could not be classified as any known subtypes (U, unclassified). The heterogeneous profile of HIV-1 infection was different from the profiles of neighboring Central African countries. These data show that subtypes G and H as well as subtype A were circulating with high prevalence. The fact that new genetic subtypes (J and U) are circulating indicates a need for a greater surveillance for these subtypes both in Congo as well as in other parts of the world.

Phylogenetic analysis of human immunodeficiency virus 1 in Ghana.

Eleven human immunodeficiency virus 1 (HIV-1) isolates from Ghanaian acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC) patients obtained by our serosurvey in 1986-1994 were genomically analyzed and phylogenetically compared with other known strains. A phylogenetic tree constructed by analyzing the env region indicated that heterogeneous HIV-1 strains were circulating in Ghana and the majority of them (9 of 11 isolates) belonged to clade (subtype) A which is now furiously epidemic in Africa. Another isolate (1 of 11) belonged to clade D, and the remaining one (1 of 11) belonged to "clade G". This "clade G" virus grouped by the env analysis belonged to clade A by its pol sequence, suggesting an A/G intersubtype recombinant. The characteristic sequences in the V3 tip which have not yet been reported were observed in these Ghanaian isolates, which should be taken into account for future vaccine programs.

PIP: The molecular epidemiology of HIV-1 in Ghana was investigated through genomic and phylogenetic analysis of isolates from 11 AIDS or AIDS-related complex patients obtained in 1986-94. A phylogenetic tree constructed by analyzing the env region indicated that heterogeneous HIV-1 strains are circulating in Ghana. 9 of the isolates belonged to clade A, 1 to subtype D, and 1 to "clade G"--an A/G intersubtype recombinant. The V3 loops of all isolates were composed of 35 amino acid residues--a characteristic not previously described. These molecular data on the genetic variability of the envelope glycoprotein of HIV-1 should be useful for future vaccine studies in West Africa.

Predominance of HIV-1 among patients with AIDS and AIDS-related complex in Ghana.

We determined the prevalence of HIV among AIDS and AIDS-Related Complex (ARC) patients seen within one year in two hospitals in southern Ghana. Subjects were screened by an ELISA procedure for anti-HIV antibodies. Specific identification of the HIV type was done with a particle agglutination (PA) kit. All PA-determined dual specimens were then confirmed by Western blotting and Pepti-Lav 1/2 monoepitope kit. Virus isolation was attempted from symptomatic patients by co-culturing patient peripheral blood monocyte cells (PBMCs) and CD4+ cell lines. PBMCs and HIV isolates were characterised by PCR. By ELISA, 43.5% of the subjects (253) had anti-HIV antibodies. Of these, 61 (24%) were HIV-1 positive and 42 (18.6%) were dually reactive by PA. However, only 19% were confirmed as true dually-infected cases by western blotting and Pepti-Lav through all 42 samples were HIV-1 positive on the two tests. No subject was infected with HIV-2 alone. Three viruses were isolated. By PCR two of them had both HIV-1 and HIV-2 proviral sequences while the third virus was HIV-1 only. HIV-1 prevalence now predominates over HIV-2 implying a switch in the HIV infection pattern in Ghana. Furthermore mixed infections exist. The predominance of HIV-1 infection in Ghana may indicate a similar trend in other parts of West Africa.

PIP: Recent studies have suggested that HIV-2 infection is becoming less prevalent in Ghana, while the prevalence of HIV-1 is increasing. To confirm such a modification in the HIV infection profile in Ghana, a 1-year serologic and molecular study was conducted among 253 patients from 2 hospitals in southern Ghana (Accra and Dzodze in the Volta region) with confirmed or suspected AIDS. All 253 serum specimens were screened with enzyme-linked immunosorbent assay (ELISA) and particle agglutination (PA); the 42 dually reactive specimens were subsequently confirmed by Western blot and Pepti-Lav tests. By ELISA, 110 samples (43.5%) were positive for anti-HIV antibodies; this rate was 39.2% in Accra and 81.0% in the Volta region. Of these, 61 (24.1%) were HIV-1 positive and 42 (18.6%) were dually reactive by PA. No case of HIV-2 alone was detected. Most dually reactive cases were a cross-reaction between genetically similar regions of the 2 HIV types. Only 19% of the 42 PA-diagnosed dually reactive specimens were confirmed by Western blot and Pepti-Lav as true cases of HIV-2 only infection, and all these specimens were strongly positive for anti-HIV-1 antibodies. 3 viruses were isolated. By polymerase chain reaction, 2 had both HIV-1 and HIV-2 proviral sequences, while the third was HIV-1 only. This study's findings provide support for the hypothesis that most individuals with antibodies to both HIV-1 and HIV-2 are probably infected with HIV-1 alone. Intensified population surveillance aimed at isolating more HIV strains in West Africa could reveal the true extent of HIV genomic variation and facilitate the design of more specific diagnostic kits.

The increased burden of tuberculous lymphadenitis in central Africa: lymph node biopsies in Lusaka, Zambia, 1981 and and 1990.

In order to assess the effect of the HIV epidemic on lymph node biopsies in Central Africa, HIV-1 serology was tested on a cohort of patients undergoing node biopsy in Lusaka in 1990, and the histology of all lymph nodes biopsied in Lusaka in 1981 and 1990 was reviewed. One hundred and eighteen lymph nodes were biopsied in 1981 and 351 in 1990. Cases of tuberculous lymphadenitis increased from 52 (31 children and 21 adults) in 1981 to 186 (22 children, 160 adults, four patients unknown age) in 1990. Sixty-eight of 77 adults (88%) with tuberculous lymphadenitis in 1990 tested HIV-positive. Cases of histology suspicious of primary HIV lymphadenopathy and nodal Kaposi's disease also increased. Cases of malignant lymphadenopathy and overall number of surgical biopsies remained equivalent for 1981 and 1990. The study concludes that the HIV epidemic has led to a large increase in diagnostic lymph node biopsies in Lusaka, mostly through an increase in HIV-related adult tuberculous lymphadenitis.

Importance of human immunodeficiency virus-associated lymphadenopathy and tuberculous lymphadenitis in patients undergoing lymph node biopsy in Zambia.

The relative importance of human immunodeficiency virus (HIV)-associated lymphadenopathy amongst patients presenting for lymph node biopsy in Central Africa is unknown. HIV-1 serology and histology of patients undergoing superficial lymph node biopsy during 1989-1990 in Lusaka, Zambia, were examined in a prospective cohort study of HIV serology and by retrospective review of laboratory records. Of 727 lymph nodes biopsied in Lusaka in 1989-1990, 380 (52 per cent) showed tuberculous lymphadenitis, 160 (22 per cent) histology suggestive of primary HIV lymphadenopathy and 66 (9 per cent) nodal Kaposi's disease. HIV serology was tested in 280 adults and was positive in 91 per cent (255 patients), including 89 per cent (153 of 171) of those with tuberculous lymphadenitis, 98 per cent (63 of 64) of those with histology suspicious of primary HIV lymphadenopathy and all (24 of 24) with nodal Kaposi's disease. Other HIV-associated lymphadenopathy included nodal lymphomas and lymphoepithelial cysts. HIV serology was tested in 22 children and was positive in eight, including four of 14 with tuberculous lymphadenitis. It is concluded that HIV-associated lymphadenopathy, especially tuberculous lymphadenitis, is very common amongst patients presenting for lymph node biopsy in Central Africa.

PIP: Data from a prospective cohort study conducted during 1989-1990 of HIV serology and from a retrospective review of laboratory records of 727 patients presenting for superficial lymph node biopsy at the University Teaching Hospital in Lusaka, Zambia, were analyzed to determine the relative significance of HIV-associated lymphadenopathy among patients undergoing lymph node biopsy. 380 (52%) of the 727 biopsy patients had tuberculous lymphadenitis (secondary HIV lymphadenopathy). Another 160 (22%) had presumed primary HIV lymphadenopathy. The remaining 66 (9%) had nodal Kaposi's disease. 280 adults were tested for HIV antibodies. 91% tested positive for HIV. The HIV rate was 89% for patients with tuberculous lymphadenitis, 98% for suspected primary HIV lymphadenopathy cases, and 100% for those with nodal Kaposi's disease. As for the 22 children 0-16 years old, 8 were HIV positive. 50% of HIV-positive children who underwent lymph node biopsy had tuberculous lymphadenitis. Three had suspected primary HIV lymphadenopathy and 1 had nodal Kaposi's disease. These findings show that HIV-associated lymphadenopathy, particularly tuberculous lymphadenitis, is very prevalent in patients undergoing lymph node biopsy. They stress the importance of investigating further HIV-positive patients with suspicious asymmetrical nodes in central Africa. Simple, appropriate methods (e.g., wide-needle aspiration) are needed for the diagnosis of tuberculous lymphadenitis in this region, with its dearth of facilities for surgery and histopathology.

Linfoma primario de intestino delgado relacionado al SIDA: informe de un caso / Primary lymphoma of the bowel related to AIDS: a case report

El linforma no Hodgkin es una neoplasia relacionada con el SIDA, cuya incidencia se incrementa a mayor duración de la infección por el VIH. Se presenta el caso de un hombre de 21 años de edad con diagnóstico de linfoma no Hodgkin inmunoblástico de células grandes, primario del yeyuno

Serological, virological, and polymerase chain reaction studies of HIV type 1 and HIV type 2 infections in Ghanaian patients with AIDS and AIDS-related complex.

We have used a particle agglutination (PA) test, Western blot (WB) test, polymerase chain reaction (PCR) test, and virus isolation to define the human immunodeficiency virus (HIV) status of 17 acquired immunodeficiency syndrome (AIDS), 6 AIDS-related complex (ARC), and 2 asymptomatic Ghanaians. HIV-1 antibodies were more frequently detected. The PCR detected 66.7% HIV-1, 11.1% HIV-2, and 5.6% of both HIV-1 and HIV-2 proviral DNA in peripheral blood mononuclear cell (PBMCs) and PBMC-Molt 4 coculture samples tested. Of the 12 viruses isolated from the 25 Ghanaians, 9 were HIV-1, 2 were HIV-2, and both HIV-1 and HIV-2 were isolated from 1 individual. Two of the HIV-1 isolates were from ARC patients who have been PA negative and either HIV-1 or HIV-2 WB indeterminate for more than 1 year without developing antibodies to HIV envelope proteins. Our results indicate that HIV-1 is now predominant in Ghanaian AIDS and ARC patients and that dual infection can occur.

PIP: While HIV is believed to be the causative agent for AIDS, many clinically diagnosed AIDS and AIDS-related complex (ARC) cases in Ghana have been reported to be negative or indeterminate for HIV antibodies. Dual seropositive reactions have also been common among AIDS and ARC cases in the country. A particle agglutination (PA) test, Western blot (WB), polymerase chain reaction (PCR), and virus isolation were used to define the HIV status of 17 AIDS, 6 ARC, and 2 asymptomatic Ghanaians. The PA test detected HIV-1 antibodies in 72% of the plasma samples, 94.4% of which were also positive according to WB. 1 sample was indeterminate by WB and 2 HIV-1 negative samples were determined to be positive by WB. HIV-2 was detected by PA in 32% of all samples, of which 87.5% were confirmed by WB. PCR detected 66.7% of HIV-1 cases, 11.1% of HIV-2, and 5.6% of both HIV-1 and HIV-2 proviral DNA in peripheral blood mononuclear cells (PBMCs) and PBMC-Molt 4 coculture samples tested. 12 viruses were isolated from the 25 subjects; 9 were identified as HIV-1, 2 as HIV-2, and 1 person was infected with both HIV-1 and HIV-2. 2 of the HIV-1 isolates were from ARC patients who had been PA-negative and either HIV-1 or HIV-2 WB indeterminate for more than 1 year without developing antibodies to HIV envelope proteins.

Evaluation of commercially available assays for antibodies to HIV-1 in serum obtained from South African patients infected with HIV-1 subtypes B, C, and D.

Between 1984 and 1990, virus was routinely isolated and serum collected from patients diagnosed at hospitals in the Western Cape as suffering from AIDS or AIDS-related conditions (ARC). From these, 17 virus strains were selected at random for sequencing and molecular characterisation of the env gene. The strains were previously characterised as belonging to HIV-1 subtypes B, C and D. The purpose of the present study was to evaluate retrospectively the serological diagnosis of HIV-1 in these 17 South African patients. Thirteen anti-HIV screening assays, including 7 rapid/simple test devices (RTDs), 4 enzyme-linked immunosorbent assays (EIAs) and 2 Western immunoblot assays were evaluated. Using commercial EIAs, 16 serum samples were HIV antibody-positive and these results were confirmed by Western immunoblot analysis. Serum from one terminal AIDS patient was found negative with all the serological tests. Some RTDs gave false negative antibody reactions on specimens from patients infected with subtype D strains. To investigate the false negative antibody reactions, the polymerase chain reaction (PCR) was used to amplify, clone and sequence proviral DNA from the immunodominant gp41 region from 7 of the HIV-1 strains. Two patients, both subtype D strains (D214 and D482) with false negative results in the RTDs, showed a significant amino acid substitution, i.e., substitution of a histidine residue for leucine at env position 607. It was concluded that although there were false negative RTD reactions on patients with HIV-1 subtype D strains, the commercial EIAs tested are sensitive and are able to detect patients infected with HIV-1 subtypes B, C and D that are present in South Africa.

An age and period reconstruction of the HIV epidemic in Italy.

BACKGROUND: The majority of AIDS cases in Italy are among intravenous drug users (68%) and homosexual men. An age, period and cohort (APC) model is presented and used to reconstruct the HIV epidemics in Italy. Projections of AIDS-related conditions (ARC) and AIDS cases are attempted based on a hypothesis of minima and an endemic hypothesis. METHODS: The model is a generalization of the usual back-calculation method which considers age, competitive mortality, susceptible population and therapy effects. Estimates of the HIV epidemic in Italy are obtained using Italian AIDS counts (corrected for delay in reporting), and an incubation time distribution (estimated from data of an Italian cohort), which was found to be dependent on the age at infection. The impact of AZT therapy, introduced in Italy in mid1987, is evaluated using a modification of the incubation time distribution dependent on period of infection. RESULTS: The estimated number of new infections in Italy declined after 1987, although the number of new AIDS cases has continued to rise, albeit less steeply in recent years. When delay in the progression to AIDS due to therapy is taken into account, the estimated number of people infected in mid1990 increases from 52,000 to 67,000, with approximately 12% of subjects already in the ARC stage. The age at maximum risk of infection is 25 years in males and 23 years in females. CONCLUSIONS: Using a hypothesis of no more HIV infections after 1990, AIDS counts would be still rising in Italy up to 1993 as a result of past infections and of the long incubation period.