Prevalence of antibody to human T cell leukemia virus type 1 (HTLV-1) in populations of Ivory Coast, West Africa

A large cross-sectional serologic survey for human T cell leukemia virus type 1 (HTLV-1) antibody was conducted in 3,177 Ivory Coast residents to evaluate the prevalence of HTLV-1 and to determine possible risk factors and correlates of HTLV-1 infection. Of the 3,177 serum samples, 110 (3.5%) were positive for antibody to HTLV-1 by indirect immunofluorescence assay and Western blot. The prevalence of HTLV-1 antibody in the general adult population was 1.8% and increased significantly with age. No difference between males (1.5%) and females (2%) was found. The highest prevalences were observed in female prostitutes (7.4%), patients with neurologic syndromes (5.8%), and lepers (13.7%). The high prevalence of HTLV-1 infection in prostitutes suggests that heterosexual contact is involved in the transmission of HTLV-1 and that prostitutes could play an important role in the spread of the virus in Africa. The high prevalence of HTLV-1 in patients with neurologic syndromes confirms the association between HTLV-1 and some type of neuropathies, as has been observed in the West Indies and Japan. The high prevalence observed in lepers deserves further investigation to find the cause of the association. Twenty-five individuals, including prostitutes, were coinfected with HTLV-1 and human immunodeficiency virus (HIV). Prospective studies are necessary to evaluate the exact role of HTLV-1 alone or in combination with HIV in inducing specific diseases.     

Prevalence of HTLV-III/LAV antibody in selected populations in Thailand

Antibody to the human T-lymphotropic virus, type III/lymphadenopathy-associated virus (HTLV-III/LAV) by ELISA test was detected in one (1%) of 101 male homosexual prostitutes (confidence limit 95%:0.03-5.4%, in two (2%) of 100 thalassemia patients, and in none (C.L. 95%:0-3.6%) of 100 female prostitutes, 99 parenteral drug abusers, 100 male VD patients, 100 consecutive blood donors in serum collected from February through June 1985. Serum from the positive homosexual subject was strongly positive on repeated ELISA testing, and was also positive by Western Blot test. The two thalassemia patients, who were repeatedly weakly-positive by ELISA, were negative by Western Blot test and presumed to be false positive reactors. Prevalence of HTLV-III/LAV virus in sexually-active homosexuals in Thailand in 1985 appears to be similar to the 1% rate among homosexuals in San Francisco in 1978 at the start of the AIDS epidemic there.     

Hospital-based surveillance for HTLV-1/2 infections in Spain

In Western countries, HTLV-1 infection is recognized mainly among foreigners coming from endemic areas. In contrast, HTLV-2 is found predominantly in native intravenous drug users (IDUs). Spain has experienced a large wave of immigration, which could have influenced the current prevalence and distribution of HTLV-1 and HTLV-2 infection. A 1-day cross-sectional survey was carried out in May 2005 in 13 hospitals distributed across Spain. A total of 2873 outpatient subjects were screened for HTLV-1/2 antibodies. Although the majority of the study population consisted of native Spaniards, 206 (7.2%) were immigrants. Two cases of HTLV-1 and one of HTLV-2 infection were found (overall prevalence, 0.1%). The two individuals with HTLV-1 were immigrants from endemic areas and the single case of HTLV-2 infection was a former Spaniard IDU coinfected with HIV-1. In summary, the current prevalence of HTLV-1/2 infection in Spain is low, with no evidence of spread beyond the classical risk groups. However, a rapidly growing population of immigrants from HTLV-1-endemic areas in Spain could modify this pattern and periodic surveillance studies including both natives and immigrants are warranted.     

Low prevalence of human immunodeficiency virus-1 (HIV-1), HIV-2, and human T cell lymphotropic virus-1 infection in Somalia.

A seroepidemiologic survey was conducted to determine the prevalence of human immunodeficiency virus type 1 (HIV-1), HIV-2, human T cell lymphotropic virus type I (HTLV-I), and Treponema pallidum infection among southern Somalis. Sera were collected from 1,269 study subjects in the urban area of the capital city, Mogadishu, and in the rural towns of Merka, Qoryoley, and Kismayo. The subjects included 57 prostitutes, 79 sexually transmitted disease (STD) patients, and 1,133 others, including outpatient and hospitalized patients with leprosy, tuberculosis, other infectious diseases, individuals from rehabilitation camps and secondary schools, and Ethiopian immigrants. Results indicated that none of the sera were positive for HIV-1 and HIV-2 by Western blot, but one was positive for HTLV-I. The prostitutes had a significantly higher prevalence of treponemal antibody (50.8%; P less than 0.0001) than either the STD patients (12.6%) or the other subjects (5.2%). Epidemiologic data indicated that 94% of the males and females were circumcised and only 2.6% of the males used condoms. Overall, the results of this study suggested a very low prevalence of HIV-1, HIV-2, and HTLV-I infections, especially among prostitutes and STD patients, who were considered at greatest risk of contracting these retroviral infections.     

Molecular analysis of human T cell lymphotropic virus type 1 and 2 (HTLV-1/2) seroindeterminate blood donors from Northeast Iran: evidence of proviral tax, env, and gag sequences

Human T cell lymphotropic virus type 1 and 2 (HTLV-1/2) Western blot indeterminate results are a problem for blood banks in endemic areas. To determine the prevalence of HTLV-1/2 infection among indeterminate donors, we analyzed 130 cases from Mashhad, an HTLV-1/2 endemic area in Northeast Iran. The most frequent Western blot bands were GD21 alone (37.2%) followed by rgp46-2 alone (32.1%). We further tested 40 available DNA samples of these cases by PCR for viral sequences, tax, gag, and pol, and found five cases (12.5%) to be positive for two or three HTLV-1 genes. There were no significant age, sex, and blood group differences between PCR-positive and PCR-negative cases. Among PCR-positive individuals, the most prevalent Western blot bands were variable combinations of rgp46-1, GD21, and gp21. The mean of the optical density (OD) of the enzyme-linked immunosorbent assay (ELISA) test was significantly higher in PCR-positive individuals. The frequency of the rgp46-1 band was also significantly higher in PCR-positive cases compared to PCR-negative ones. In conclusion, the majority of HTLV-indeterminate donors lack the HTLV provirus and therefore are not considered infected. However, in some cases with higher ODs in the ELISA test and seroreactivity to env proteins, rgp46-1 and GD21 in particular may be indicative of infection and need further evaluation by molecular methods.     

Prevalence of infection by human T Cell lymphotropic viruses (HTLV-1/2) in adult population in Vitória-ES

Introduction: Brazil has a high number of HTLV-1/2 infections which are unequally distributed in the country. Most prevalence studies have focused on specific populations, such as blood donors and pregnant women. Some areas, for example the state of Bahia, have robust information about HTLV-1/2 infection, however there is no information available about this infection in the general population of Vitória, Espírito Santo, Brazil. Objective: To determine the prevalence of HTLV-1/2 infection in adults from the municipality of Vitoria, ES. Methods: A cross sectional study was performed from September 2010 to December 2011, in individuals of both sexes, aged 18 or older living in Vitória-ES. Venous blood samples were collected and tested for anti-HTLV-1/2 antibodies by chemiluminescent immunoassay (CMIA). Individuals with CMIA reactive results were submitted to a new blood collection for retesting by CMIA, followed by PCR to confirm infection and discriminate the viral type. Results: From 1502 tested samples, eight were reactive in CMIA and all were confirmed by PCR. Therefore, the prevalence of HTLV-1/2 was 0.53% (8/1502, 95% CI: 0.2–1.0%). The infection rate was 0.7% in men (5/711, 95% CI: 0.17–1.51%), and 0.38% in women (3/791, 95% CI: 0–0.81%). Conclusions: The prevalence of HTLV-1/2 infection was 0.53% (8/1502; 95% CI: 0.2–0.9%). Confirmatory test using real-time PCR (qPCR) identified seven individuals positive for HTLV-1 and one for HTLV-2. Considering the risk of infected individuals to develop high morbidity and mortality diseases, it would be important to implement public health policies aimed at stopping transmission of these viruses in this municipality.     

The prevalence of HCV antibodies in 3 groups with distinct patterns of sexual activity]

We studied the prevalence of antibodies to hepatitis C virus (anti-HCV) among 164 heterosexual partners of anti-HCV-positive subjects, 131 prostitutes and 52 homosexual men. 6.7% of heterosexual monogamous partners had anti-HCV; the seropositivity rate was associated with a long-term sexual practice and with age. Of the 131 prostitutes, 6 (4.6%) had anti-HCV; there were significant associations in patients positive for anti-HCV, with a history of parenteral drug addiction. 11.5% of homosexual men were anti-HCV positive; there were significant associations with positivity for antibodies to HIV, intravenous drug abuse and with the number of sexual partners. We concluded that the HCV may be transmitted by sexual route, but the high seroprevalence among prostitutes and homosexuals may be explained by other parenteral mechanisms.     

Prevalence of antibody to human T cell lymphotropic virus types 1/2 among aboriginal groups inhabiting northern Argentina and the Amazon region of Peru.

We carried out a seroepidemiologic survey to define the prevalence of human T cell lymphotropic virus types 1/2 (HTLV-1/2) infections among aboriginal populations from isolated regions of northern Argentina and the Amazon region of Peru. Antibodies against HTLV were measured with agglutination tests and confirmed with by an immunofluorescence assay (IFA) and Western blotting. Five (6.94%) of 72 samples from the Tobas Indians in Argentina were positive by the IFA; two samples were typed as HTLV-1 (2.78%), two as HTLV-2 (2.78%), and one (1.39%) could not be typed because it had similar antibody titers against both viruses. No positive samples were found among 84 Andinos Pune?os and 47 Matacos Wichis Indians. Seroprevalences of 2.50% (1 of 40) and 1.43% (1 of 70) for HTLV-1 were observed among Wayku and San Francisco communities in the Amazon region of Peru, and seroprevalences of 4.54% (1 of 22) and 2.38% (1 of 42) for HTLV-2 were observed among Boca Colorada and Galilea communities. No serologic evidence of human immunodeficiency virus (HIV) infection was found among the Indians tested. These results indicated the presence of HTLV-1 and HTLV-2 in the indigenous populations of Argentina and Peru. Moreover, the lack of HIV infection indicates that the virus has probably not yet been introduced into these populations.     

No evidence for an effect of the CCR5 delta32/+ and CCR2b 64I/+ mutations on human immunodeficiency virus (HIV)-1 disease progression among HIV-1-infected injecting drug users

The relationship between CCR5 and CCR2b genotypes and human immunodeficiency virus (HIV)-1 disease progression was studied among the 108 seroconverters of the Amsterdam cohort of injecting drug users (IDUs). In contrast to earlier studies among homosexual men, no effect on disease progression of the CCR5 Delta32/+ and the CCR2b 64I/+ genotypes was found, when progression to AIDS, death, or a CD4 cell count <200/microL was compared by a Cox proportional hazards model. Furthermore, CD4 cell decline (by a regression model for repeated measurements) and virus load in the first 3 years after seroconversion did not differ between the CCR5 and CCR2b wild type and heterozygous genotypes. A nested matched case-control study also revealed no significant effect of the CCR5 and CCR2b mutations. Immunologic differences between IDUs and homosexual men may account for the observed lack of effect. Alternatively, difference in transmission route or characteristics of the HIV-1 variants that circulate in IDUs could also explain this phenomenon.     

Hepatitis C virus among genitourinary clinic attenders in Scotland: unlinked anonymous testing

Our objective is to gauge the prevalence of hepatitis C virus (HCV) antibodies among a population at risk of contracting sexually transmitted infections (STIs) and, thus, the efficiency with which the virus is transmitted sexually. The investigators undertook an unlinked anonymous HCV antibody testing study of residual syphilis serology specimens taken from attenders of genitourinary clinics in Glasgow, Edinburgh and Aberdeen during 1996/97. The results were linked to non-identifying risk information. Anti-HCV prevalences among non-injecting heterosexual men and women, and non-injecting homosexual/bisexual males ranged between 0 and 1.2%; the only exception to this was a 7.7% (4/52) prevalence among homosexual/bisexual males in Aberdeen. The overall anti-HCV prevalence for homosexual/bisexual males was 0.6% (4/668), for heterosexual males 0.8% (32/4135), for heterosexual females 0.3% (10/3035) and for injecting drug users 49% (72/148). Only 3 (all female) of the 46 non-injectors who were antibody positive were non-UK nationals or had lived abroad. HCV antibody positive injectors were less likely to have an acute STI and more likely to know their HCV status than non-injectors; no differences in these parameters were found between positive and negative non-injectors on anonymous HCV antibody testing. Our findings are in keeping with the prevailing view that HCV can be acquired through sexual intercourse but, for most people, the probability of this occurring is extremely low. Interventions to prevent the spread of HCV should be targeted mainly at injecting drug user (IDU) populations.     

Predominance of human lymphotropic T cell virus type 2 subtype B in urban populations of Argentina

Human T-lymphotropic virus subtype b (HTLV-2b) infection has been described among aborigines from Northern Argentina, while HTLV-2a has been described in an injecting drug user (IDU) from a Central region, similar to the situation in Spain, the United States, and Brazil. In this study, 22 of the 26 strains analyzed from blood donors and HIV-1(+) individuals were HTLV-2b (84.6%) clustering with Amerindian references, while 4 HIV-1(+) (15.4%) were HTLV-2a. HTLV-2a sequences were closely related to Brazilian references in contrast to the previous Argentinean IDU strain that clustered with Africans and Amerindians from North America. In summary, these findings show that HTLV-2b is the major strain circulating in an urban population of Argentina. HTLV-2a/b could have been introduced from endemic South American countries such as Brazil and because of contact with other populations such as IDUs from Europe despite its introduction due to the increasing internal migration of aborigines to large urban centers. Considering this results and recent data about the dissemination of HTLV-1 in residents of Buenos Aires city, new studies among non-at-risk groups for HTLV-1/2 infection should be performed.     

Risk factors for HIV-1 infection in a British population: lessons from a London sexually transmitted diseases clinic

Between September 1985 and June 1988, 6923 people (4550 men and 2373 women) were tested for HIV-1 antibodies at a sexually transmitted disease clinic, London, UK. Of the 6923 individuals tested, 558 (8%) were seropositive, of whom 523 (94%) were men and 35 (6%) women. Of the seropositives, 84% were homosexual or bisexual men, 5% were intravenous drug users, 4% were heterosexual contacts of HIV seropositives, 4% had multiple risk factors, 2% were heterosexual contacts of central African partners and 1% were heterosexuals with no other risk factors. This prevalence pattern conforms to that observed in other industrialized nations. For the women, heterosexual intercourse with an HIV-infected partner, intravenous drug use and heterosexual contact with a partner from central Africa were the main risk factors for infection. The important risk factors among the men were heterosexual contact with an HIV-seropositive partner, being homosexual or bisexual, intravenous drug use and heterosexual contact with a resident from central Africa. heterosexual and homosexual transmission were implicated as the main routes for viral spread in this British population.     

Epidemiology of HIV in Estonia

The aim of this study was to report on the epidemiology of HIV infection in Estonia and to molecularly characterize Estonian HIV-1 variants. Epidemiological data were obtained from the Estonian National HIV/AIDS Database. In 1995-1996 blood samples were collected from 54 of the 65 HIV-infected individuals that had been diagnosed at that time. The V3 domain of the env gene was directly sequenced from peripheral blood mononuclear cells of 49 of these 54 individuals and the sequences used for phylogenetic analyses. At the end of 1999 Estonia reported 96 diagnosed HIV cases; 46 (48%) were homosexual or bisexual men and 31 (32%) were presumed to have been infected heterosexually. Importantly, only four individuals were likely to have become infected through intravenous drug use. Forty-three individuals (45%) were presumed to have been infected outside of Estonia, whereas 38 (40%) were likely to have become infected in Estonia. As expected, a majority of the investigated individuals (80%) were found to carry subtype B virus. Infections with subtypes A, C, D, G, and CRF02_AG were also documented. The dominance of subtype B was restricted to homosexual and bisexual men. Thus, subtype B infections were documented in 33 of 34 (97%) homosexual and bisexual men, but only 6 of 15 (40%) individuals with other probable routes of infection. Thirty of the 39 subtype B sequences were joined in a tight sequence cluster that also included sequences from neighboring Russia and Lithuania. This pattern suggests a local spread of HIV-1 among homosexual and bisexual men within the region. The results from the phylogenetic analyses agreed well with other epidemiological information. In conclusion, Estonia remains a country with a low prevalence of HIV infection. A majority of the identified cases are homosexual or bisexual men, whereas HIV infection among intravenous drug users is rare. A large proportion of the homosexual and bisexual men carried closely related subtype B variants. The sequences have been deposited in GenBank under accession numbers AF286538-AF286586.     

Long terminal repeat sequence analysis of HTLV-2 molecular variants identified in Southern Brazil

In Brazil, human T-lymphotropic virus type 2 (HTLV-2) is endemic in Amerindians and epidemic in intravenous drug users (IDUs). The long terminal repeat (LTR) is the most divergent genomic region of HTLV-2, therefore useful to characterize subtypes. Nucleotide sequence and restriction fragment length polymorphism (RFLP) analysis of LTR genomic segments of fourteen HTLV-2 strains isolated from HIV-infected patients of Londrina, Southern Brazil, were carried out. Molecular analysis disclosed that all HTLV-2 strains belonged to 2a subtype, and RFLP detected the presence of the a4, a5, and a6 subgroups according to Switzer's nomenclature. RFLP correlated with nucleotide sequence, and phylogenetic analysis clustered HTLV-2 sequences of IDUs into subgroups a5 and a6. HTLV-2 sequences from individuals of sexual risk factor clustered into the a4 subgroup. These results extend the knowledge of the genetic diversity of HTLV-2 circulating in Brazil and provide insights into HTLV-2 transmission and virus movement in this geographic area.     

HTLV-1/2 seroprevalence and coinfection rate in Brazilian first-time blood donors: an 11-year follow-up

The seroprevalence and geographic distribution of HTLV-1/2 among blood donors are extremely important to transfusion services. We evaluated the seroprevalence of HTLV-1/2 infection among first-time blood donor candidates in Ribeir?o Preto city and region. From January 2000 to December 2010, 1,038,489 blood donations were obtained and 301,470 were first-time blood donations. All samples were screened with serological tests for HTLV-1/2 using enzyme immunoassay (EIA). In addition, the frequency of coinfection with hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), Chagas disease (CD) and syphilis was also determined. In-house PCR was used as confirmatory test for HTLV-1/2. A total of 296 (0.1%) first-time donors were serologically reactive for HTLV-1/2. Confirmatory PCR of 63 samples showed that 28 were HTLV-1 positive, 13 HTLV-2 positive, 19 negative and three indeterminate. Regarding HTLV coinfection rates, the most prevalent was with HBV (51.3%) and HCV (35.9%), but coinfection with HIV, CD and syphilis was also detected. The real number of HTLV-infected individual and coinfection rate in the population is underestimated and epidemiological studies like ours are very informative.     

Updates on the Epidemiology of the Human T-Cell Leukemia Virus Type 1 Infection in the Countries of the Eastern Mediterranean Regional Office of the World Health Organization with Special Emphasis on the Situation in Iran

Background: The epidemiology and prevalence of the Human T-cell leukemia virus type-1 (HTLV-1) infection represent a recommended priority by global health agencies. An in-depth revision to update the status of this infection in countries including those of the Eastern Mediterranean Regional Office (EMRO) of the World Health Organization is hence required. Methods: Ninety-seven studies evaluating the HTLV-1 infection in low- and high-risk populations in EMRO countries were retrieved from the international electronic databases and were used to assess the epidemiological status of the infection in these countries. Results: Most epidemiologic reports were published from Iran, with more than 50% of Iranian prisoners and around 4% of healthy individuals reported to have the infection. In Egypt, a considerable prevalence of the virus spans around 1.11% of blood donors. Foci of HTLV-1 infection are also present in some countries and require a careful epidemiological evaluation. In the other EMRO countries, a lower prevalence that does not exceed 1% was reported. Conclusion: The epidemiology and prevalence of HTLV-1 in the EMRO countries require a tight revision and update. Published studies reveal a scarce distribution of the virus in the African countries of EMRO, while a lower prevalence is denoted in the Asian countries of EMRO, except in Iran, where the prevalence is high.     

Prevalence of Hepatitis C Virus Infection in Different Population Groups in Southern Italy

Abstract Background: A cross-sectional investigation was carried out between 2000 and 2002 to assess the prevalence of hepatitis C virus infection (HCV) in Naples, southern Italy. Patients and Methods: Five groups of individuals were investigated, two at low risk and three at high risk for HCV infection. Blood sample sera were collected among 5,391 individuals (4,059 men and 1,332 women): 1,972 general practitioner (GP) patients and 781 employees of the National Cancer Institute (NCI) of Naples (low-risk groups); 524 male prisoners, 1,436 intravenous drug users (IDUs) and 678 hemodialysis patients (high-risk groups). Results: Overall HCV seropositivity rates ranged from 6.4% among employees of the NCI to 37.4% among male prisoners. HCV infection tended to generally increase with age, but in IDUs and in male prisoners the upward trend leveled off at 50 years of age. As compared to GP patients, IDUs (both sexes) and male prisoners had a nearly 6-fold increased risk of HCV infection, while HCV was nearly 3-fold more common among hemodialysis patients. Employees of NCI were at reduced risk of HCV infection, particularly women (odds ratio = 0.3). Conclusion: The study findings confirmed the high risk for HCV infection in IDUs and identified other population groups in southern Italy that should be offered HCV screening and counselling given the servere implications of HCV infection on health.An erratum to this article can be found at     

High rate of nonspecific anti-hepatitis C reactivity amongst homosexual men in comparison with that found in other sexually active groups and blood donors

Abstract. Objectives . To investigate the concordance of antihepatitis C virus (anti-HCV) reactivity by a second-generation enzyme immunoassay (EIA-2) and by a four-antigen recombinant immunoblot assay (4-RIBA) in homosexual men, in comparison with that found in other sexually active groups and blood donors. Design . Prospective study. Setting . Tertiary referral centre, Seville, Spain. Subjects . A total of 1203 subjects were studied. Eight hundred and three were sexually active individuals: 547 female prostitutes, 88 heterosexual men who had frequent sexual intercourse with prostitutes, and 168 homosexual men. All of them denied blood transfusion and parenteral drug use. In addition, 400 voluntary blood donors were selected at random. Main outcome measures . All serum samples were screened for anti-HCV by EIA-2 and repeatedly reactive sera were tested by 4-RIBA. Homosexual men were also screened for anti-human immunodeficiency virus (anti-HIV), hepatitis B virus (HBV) markers and gammaglobulin concentration. Finally, serum samples from homosexual men reactive for anti-HCV by EIA-2 were analyzed for HCV-RNA by polymerase chain reaction (PCR). Results . Concordance between EIA-2 and 4-RIBA in female prostitutes (71.4%), clients of prostitutes (75.0%), and blood donors (83.3%) was significantly higher than in homosexual men (38.8%) (P < 0.04). In this collective the concordance between 4-RIBA and PCR was 85.7% for positive cases and 88.8% for negative ones, and EIA-2 ratios in reactive sera were significantly higher in 4-RIBA confirmed cases (P < 0.0001). No correlation between false positive EIA-2 results and presence of HIV infection, HBV markers or hypergammaglobulinaemia was found in homosexual men by univariate analysis. Conclusions . There is a high level of non-specific anti-HCV reactivity by EIA-2 amongst homosexual men in comparison with that found in other sexually active groups and blood donors. The true prevalence of HCV infection amongst homosexual men could be even lower than previously described.     

Human T cell lymphotropic virus type 1 infection among men who have sex with men in Central Brazil

Human T cell lymphotropic virus type 1 (HTLV-1) was the first retrovirus discovered in humans and is endemic in several parts of the world. Because of risk behaviors, mainly sexual, men who have sex with men (MSM) are at high risk of acquiring HTLV-1 infection. A cross-sectional study was performed to estimate the prevalence of HTLV-1 infection, to characterize genetically HTLV-1 sequences and to identify risk behaviors associated with this infection among MSM in Central Brazil. A total of 430 MSM were enrolled in this study and three were shown to be HTLV-1 infected, prevalence of 0.7% (95% confidence interval: 0.4–0.9). Phylogenetic analysis showed that all HTLV-1 positive samples belonged to Cosmopolitan subtype Transcontinental subgroup A. Although the prevalence rate of HTLV-1 infection found in this study was similar to that observed among Brazilian blood donors, additional HTLV-1 preventive interventions need to be further implemented because this population is engaged in high-risk sexual behavior.