Two simultaneous hepatitis B virus epidemics among injecting drug users and men who have sex with men in Buenos Aires, Argentina: characterization of the first D/A recombinant from the American continent.

Previous studies have revealed that hepatitis B virus (HBV)/D and HBV/F predominate among blood donors from Buenos Aires, Argentina. In the present study, blood samples from two high-risk groups were analysed: 160 corresponding to street- and hospital-recruited injecting drug users [81.2% showing the 'anti-hepatitis B core antigen (anti-HBc) only' serological pattern] and 20 to hepatitis B surface antigen (HBsAg)(+)/anti-HBc(+) men who have sex with men. HBV genotypes were assigned by polymerase chain reaction amplification followed by restriction fragment length polymorphism and confirmed by nucleotide sequencing of two different coding regions. HBV DNA was detected in 27 injecting drug users (16.9%, occult infection prevalence: 7.7%), and 14 men who have sex with men (70%). HBV/A prevailed among injecting drug users (81.8%) while HBV/F was predominant among men who have sex with men (57.1%). The high predominance of HBV/A among injecting drug users is in sharp contrast to its low prevalence among blood donors (P = 0.0006) and men who have sex with men (P = 0.0137). Interestingly, all HBV/A S gene sequences obtained from street-recruited injecting drug users encoded the rare serotype ayw1 and failed to cluster within any of the known A subgenotypes. Moreover, one of the HBV strains from a hospital-recruited injecting drug user was fully sequenced and found to be the first completely characterized D/A recombinant genome from the American continent. Data suggest that two simultaneous and independent HBV epidemics took place in Buenos Aires: one spreading among injecting drug users and another one sexually transmitted among the homosexual and heterosexual population.

Seroprevalence of and risk factors for HIV-1 infection among female commercial sex workers in South America.

OBJECTIVE: Assessment of HIV prevalence and associated risk behaviours among female commercial sex workers (FCSW) across major cities in South America. METHODS: Seroepidemiological, cross sectional studies of 13 600 FCSW were conducted in nine countries of South America during the years 1999-2002. Participants were recruited in brothels, massage parlours, hotels, and streets where anonymous questionnaires and blood samples were collected. HIV infection was determined by enzyme linked immunosorbent assay (ELISA) screening and western blot confirmatory tests. RESULTS: The overall HIV seroprevalence was 1.2% (range 0.0%-4.5%). The highest HIV seroprevalences were reported in Argentina (4.5%) and Paraguay (2.6%); no HIV infected FCSW were detected in Venezuela and Chile. Consistent predictors of HIV seropositivity were: (1) a previous history of sexually transmitted infections (STI, AORs = 3.8-8.3), and (2) 10 years or more in commercial sex work (AORs = 2.2-24.8). In addition, multiple (> or =3) sexual contacts (AOR = 5.0), sex with foreigners (AOR = 6.9), use of illegal drugs (AOR = 3.2), and marijuana use (AOR = 8.2) were associated with HIV seropositivity in Southern Cone countries. CONCLUSIONS: Consistently low HIV seroprevalences were detected among FCSW in South America, particularly in the Andean region. Predictors of HIV infection across the continent were STI and length of commercial sex work; however, use of illegal drugs, especially marijuana, and sexual contacts with foreigners were also found to be associated risk factors in the Southern Cone region. Interventions for the control of HIV and other STI need to be region and country specific; drug use appears to have an ever increasing role in the spread of HIV among heterosexually active populations.

Documentation of subtype C HIV Type 1 strains in Argentina, Paraguay, and Uruguay.

HIV subtypes B, F, and BF recombinants have been previously reported in South America. This report describes the presence of HIV-1 subtype C infection in the countries of Argentina, Uruguay, and Paraguay dating back to at least 1999. Surveillance for uncommon non-B/non-F subtype viruses circulating in South America has been conducted in samples obtained from nine countries. Peripheral blood mononuclear cells (PBMC), dried filter paper (FP), and fresh blood (FB) samples were collected from HIV-positive patients from Ecuador, Colombia, Venezuela, Peru, Chile, Bolivia, Argentina, Uruguay, and Paraguay. From a total of 2962 HIV seropositive samples examined during a 9-year period (1995-2003), only 11 (0.4%) were found to be infected with non-B/non-F HIV variants. Eight of these 11 strains were determined to be subtype C by heteroduplex mobility assay (HMA). Five of these 8 strains were further characterized by sequencing and phylogenetic analysis of the protease (Pro) and reverse transcriptase (RT) region of the genome and two were sequenced full length. One of the strains was found to be a unique BC recombinant. The spread of a third subtype of HIV, subtype C, should raise the question of its potential future role in the HIV epidemic in this region.

Long-lasting astrocyte reaction to persistent Junin virus infection of rat cortical neurons.

Immunoperoxidase labeling was performed in histological sections from rat brain harvested during acute (10-30 days), clinically inapparent (90-270 days) and late (450-540 days) stages of Junin virus-induced neurological disease. In frontoparietal cortex, count of viral antigen (+) neurons peaked during the acute period (27.7+/-6.8), dropped within the intermediate (4.8+/-4.0 to 1.4+/-1.1) and increased (7.6+/-4.3) at the onset of the late neurological syndrome. In infected vs. control rats, the number of GFAP (+) astrocytes maximized during the acute stage (19+/-4 vs. 11+/-5), and from the end of the intermediate (27+/-5 vs. 21+/-5) up to the late (37+/-7 vs. 26+/-6) periods. In turn, surface density of GFAP (+) material in infected samples peaked at 0.196+/-0.066, while it failed to exceed 0.090+/-0.043 in controls. Both astrocyte hypertrophy relapsing into chronicity, as depicted by surface density, and astrocyte hyperplasia preceding the onset of the late neurological syndrome, support their pathogenic contribution to disease expression.

Underestimation of Mycobacterium tuberculosis infection in HIV-infected subjects using reactivity to tuberculin and anergy panel.

BACKGROUND: This study aimed to evaluate purified protein derivative (PPD) reactivity and its interrelationship with anergy panel and CD4+ lymphocytes in HIV-infected subjects as compared to PPD reactivity in HIV-uninfected individuals in a tuberculosis endemic and high Bacillus Calmette-Guérin (BCG) coverage environment. METHODS: Clients of four Mexico City HIV detection centres were screened for HIV-1 antibodies (ELISA or haemagglutination, Western Blot); reactivity to PPD (Mantoux PPD, 5TU RT-23), Candida (1:1000, 0.1 ml), and tetanus toxoid (10Lf, 0.1 ml); and CD4+ T cells. Active tuberculosis was excluded. Informed consent was obtained. RESULTS: From 5130 clients 1168 subjects were enrolled; of these 801 (68.6%) were HIV positive. Reactivity to PPD among HIV-positive subjects was found in 174 (22%), 261 (32.6%), and 296 (37%), at PPD cutoff levels of > or =10 mm, > or =5 mm, and > or =2 mm as compared to 224 (61%) of 367 HIV-negative individuals' reactors to PPD (> or =10 mm) (P < 0.001). After exclusion of anergic individuals using two cutoff levels for cutaneous allergens (< or =2 mm and < or =5 mm), PPD reactivity between HIV-infected and uninfected individuals continued to be significantly different. Only HIV-infected individuals with CD4+ T cells > or =500 cells/mm3 had similar reactivity to PPD as HIV-uninfected individuals. Variables associated with PPD reactivity were CD4+ T cell counts, BCG scar, HIV infection and age. CONCLUSIONS: PPD reactivity was useful to diagnose tuberculosis infection only among HIV-infected individuals with CD4+ counts > or =500 cells/mm3. Among individuals with lower counts, lowering cutoff levels or using anergy panel did not permit comparable reactivity as that observed among HIV-uninfected individuals.

Digesto de leyes nacionales y provinciales de la República Argentina sobre VIH/SIDA

Argentina. Presenta leyes referentes a: medidas epidemiológicas; derecho a la salud; derecho a la intimidad y a la confidencialidad - secreto profesional; derecho a la liberdad personal; derecho de circulación y residencia; principio de igualdad; derecho al trabajo; medidas de bioseguridad; seguridad social; y derecho de família. Presenta, también, las normas citadas y bibliografía. Documento en formato pdf; requiere Acrobat Reader

Opportunistic infections in pediatric HIV infection: a study of 74 autopsy cases from Latin America. The Latin American AIDS Pathology Study Group.

The present report describes opportunistic infections found at 74 autopsies of pediatric HIV/AIDS patients performed at several hospitals in Latin American countries. Fungal infections were the most common (53 cases), Candida sp. (39.18%) and Pneumocystis carinii (20.27%) being the most frequently recognized. Other fungal diseases included histoplasmosis, aspergillosis, and cryptococcosis. Viral infections were present in 31 cases, 38.7% being due to cytomegalovirus. Other viruses recognized included herpes simplex and adenovirus. Additional opportunistic infections were due to Mycobacterium avium-intracellulare, toxoplasmosis, and tuberculosis. Nonspecific bacterial bronchopneumonia was present in 11 cases. Cytomegalovirus and P. carinii coinfection was the most common association found. In this series patients died at a younger age (72% at or younger than 1 year old) and there was a slightly higher number of cases of histoplasmosis and brain toxoplasmosis than in other previously published series of infants and children.

Serological evidence of human Hantavirus infection in Argentina, Bolivia and Uruguay.

A serological survey was conducted in 1985-1987 to determine the presence of infection for Hantavirus in the general population in Argentina, Uruguay, Paraguay and Bolivia, as well as among rodent-exposed laboratory workers in Argentina. Out of 748 individuals tested by immunofluorescence 20 proved positive for Hantaan virus 76/118 strain of whom 16 also reacted against Seoul virus 80/39 strain and 2 against Puumala virus Sotkamo strain. Ten out of 72 Argentine laboratory workers were positive for the first 2 viruses by ELISA, immunofluorescence and/or plaque reduction neutralization test, in 4 of whom recent infection was demonstrated by IgM antibody presence. Inapparent Hantavirus infection was thus demonstrated for the first time in 2.7% of regional inhabitants, together with 13.9% among rodent-exposed laboratory workers. Our data established the existence of human Hantavirus infection nearly 10 years before the recognition of clinical cases of hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome in Argentina.

Hantavirus pulmonary syndrome in Argentina. Possibility of person to person transmission.

In March 1995 the first case of a familiar outbreak of Hantavirus pulmonary syndrome (HPS) was notified in El Bolson, in the South of Argentina. Until December 15, 1996, a total of 77 cases of HPS had been notified with 48% mortality, distributed in three geographical areas of the country, South, North and Center. During 1996, of the 19 cases from El Bolsón, three were local physicians, one of whom -during the prodrome of her illness- travelled to Buenos Aires to be attended. In the hospital, two of the physicians who assisted her, developed HPS 27 and 28 days after the first contact. These data suggest for the first time the possibility of interhuman transmission of the Hantavirus responsible for the pulmonary syndrome.

HIV/AIDS and its interaction with tuberculosis in Latin America and the Caribbean.

At present, human immunodeficiency virus (HIV) is thought to have infected over 17 million people worldwide, over 1 million in North America and roughly 2 million in Latin America and the Caribbean. By comparison, infection with the tuberculosis (TB) agent Mycobacterium tuberculosis is far more common, current estimates indicating that roughly one-third of the world's population is infected. These two infections tend to aggravate each other. That is, HIV leads to a progressive immune system depression that favors reactivation of TB in people with latent tuberculous infections; it promotes progression of TB primary infections or reinfections to full-blown tuberculous disease; and it fosters TB transmission, because those simultaneously infected with HIV and M. tuberculosis tend to develop a bacilliferous and contagious TB that can be transmitted to other susceptible individuals, even though the latter are HIV-negative. In addition, this coinfection tends to promote circulation of drug-resistant M. tuberculosis and to produce peculiar manifestations that complicate TB diagnosis, treatment, and control. Overall, it seems clear that the growing threat posed by these associated agents demands effective action in the form of well-coordinated measures involving throughgoing participation by all countries.

Acute lower respiratory infection in Argentinian children: a 40 month clinical and epidemiological study.

In a total of 1,003 children (805 inpatients and 198 outpatients) with acute lower respiratory infections (ALRI), clinical, social, and environmental data were analyzed. The major clinical entities were bronchiolitis, pneumonia, bronchitis, and laryngitis. The first two of these predominated in inpatients; pneumonia and bronchitis were more common in older children, while bronchiolitis was observed in infants. Respiratory rates of > 50/min. were more common in younger children and in cases with bronchiolitis and bronchitis. Retractions showed markedly less age-dependent variations and were present in all severe cases with different clinical diagnoses. Retractions alone or associated with cyanosis were the best indicators for severity of ALRI. Among outpatients, fever and wheezing were more common; inpatients were younger, more frequently malnourished, and from a lower socioeconomic level; family history of chronic bronchitis, crowding, and parental smoking also prevailed in this group. Family asthma and exposure to domestic aerosols was more common among outpatients. Prematurity rate (17 and 15%) of all ALRI cases was twice that of the general pediatric population and a significant difference existed between in- and outpatients under 6 months of age when perinatal respiratory pathologies predominated among inpatients. It is suggested to consider the need for assessing personal, family, and environmental risk factors in addition to clinical signs and symptoms when severe cases of ALRI are evaluated.

Role of drug injection in the spread of HIV in Argentina and Brazil.

Drug injectors' have become the second largest HIV transmission category in Argentina and Brazil, as is the case in many pattern I countries, making up more than one-quarter of all AIDS cases reported by 1991. HIV seroprevalence data suggest that the expanding proportion of AIDS cases attributable to drug injection stems from an absolute increase in the number of AIDS cases among drug injectors, and is not merely reflective of a decline in the proportion of cases reported in other transmission categories. Results of a review of studies in Argentina and Brazil indicate that HIV seroprevalence is increasing rapidly, contrary to the situation in some pattern I countries in which HIV seroprevalence among drug injectors is either stably high or increasing only slightly. Also contrary to most pattern I countries, cocaine rather than heroin is the injected drug of choice in Argentina and Brazil. Given that injectors of cocaine are more likely to be HIV infected than are heroin injectors, differences in the type of drug injected between countries may have distinct epidemiological consequences on the spread of HIV.

PIP: AIDS cases attributable to using contaminated needles in nonmedicinal drug injection have increased in Argentina from 11.3% in 1987 to 39% in 1991. A similar increase (from 1.8% in 1985 to over 30% in 1991) occurred in Brazil. To complement existing information, data searches were conducted and personal communications from current researchers were collected for a total of 24 documents from Argentina and 18 from Brazil. The median sample size was 68 in Brazil and 188 in Argentina; most studies were from outpatient facilities, males constituted more than two-thirds of the sample in half of the studies, and the median age (when reported) was between 16 and 29 years old. Analysis of data from selected studies showed that HIV seroprevalence among drug injectors in both countries has increased rapidly, with the greatest increase occurring in Brazil. This rapid increase may also be influenced by the fact that cocaine, rather than heroin, is the drug of choice. Cocaine injection involves drawing blood into the syringe before injection and also more frequent injections. The level of seroprevalence among drug injectors varies among different subpopulations. Sexually transmitted disease clinic attenders who are IV drug users show rates of 6.58% and 51.9% seropositivity. Incarcerated persons who are drug injectors were associated with seropositivity rates of 35% (adults), 60.9% (adolescents), 53.5% (adolescents in security institutes), and 18% (female inmates who volunteered for testing), with drug injection the most important risk factor in 90.4%. Among prostitute injectors, rates were reported of 20% in 1988 and 50% in 1989-90 in the same population. Street children in Rio de Janeiro who use IV drugs (68 of 3389 surveyed) had a rate of 13.2% in 1987-88. The risk factors associated with HIV infection among drug injectors are socioeconomic status and injecting and sex practices. Co-infection patterns among drug injectors have also been found, with concomitant HIV-1 and HTLV-1 reported in 20% of 85 HIV positive drug injectors. Overall, these data suggest that there is an absolute increase in the number of AIDs cases among drug injectors rather than a decline in the proportion of cases reported in other transmission categories. Drug injector transmission poses a threat to the sex partners and offspring of injectors and provides a bridge to the heterosexual infection of women. While there is no obvious quick solution to the problem of IV drug use, there are programs which can slow the spread of HIV among injectors. It is urgent to control sexual transmission and drug injection transmission of HIV in these countries.

[Preliminary study on the presence of arbovirus in the populations of Corrientes and Misiones]. / Estudio preliminar sobre la presencia de arbovirus en poblaciones de Corrientes y Misiones.

Human seroprevalence of Flavivirus was determined by hemagglutination inhibition tests on 479 sera from Misiones and 49 from Corrientes provinces. Paraná and Uruguay river bank communities from Argentina and neighbouring countries carry out frequent traffic across the rivers. With the aim of searching for a possible introduction of Dengue virus from Brasil or/and Paraguay, reactivity among people from Paraná and Uruguay river communities was compared with those from mountain communities. Two sera from Ituzaingó (Corrientes Province) were positive for Dengue 2. In Misiones, 3 sera from Oberá and 2 from Montecarlo were reactive for Dengue 2 and 1 serum from Puerto Iguazú was reactive for Dengue 1. Seroprevalence among the river population was significatively higher than among the mountain population. Likewise, populations on Paraná river showed more positive sera than those on Uruguay river; 54% of the samples possessed titers for SLE virus higher than for Dengue or Yellow fever. Anti-alphavirus (EEE and WEE) antibodies tested in sera from Misiones people showed a complementary distribution pattern to flavivirus. Seroprevalence of anti-alphavirus antibodies was higher in the mountain than in the river populations.

AIDS heterosexual predominance in the Dominican Republic.

AIDS surveillance data from the Dominican Republic are described for 1983-89. A positive serologic test for HIV was required, and standard clinical criteria were used for defining AIDS. There were 1,202 AIDS cases (820 men, 372 women, 10 of unknown gender) reported to the Ministry of Health, for a cumulative case rate of 17 per 100,000 persons. Rapid growth of the epidemic is noted, with 43% of the total cases reported in 1989. Heterosexual exposure accounts for 53% (593) of all cases, with a male-to-female ratio of 2.2:1, resembling a World Health Organization Pattern I/II country. Prevalence is highest in and surrounding the urbanized tourist areas of Santo Domingo and Puerto Plata and in districts with a high concentration of sugar plantation barracks, where laborers from Haiti and the Dominican Republic work and live. The distribution of AIDS cases is described by transmission exposure category, age, sex, year of diagnosis, and district. The National AIDS Surveillance Program can be improved by validation of exposure transmission categories through selected case investigation and by better reporting through training of health care providers. Surveillance data will assist in targeting future public health efforts to regions and persons at highest risk.