Surveillance of human retroviruses in blood samples from patients with hepatitis B and C in São Paulo, Brazil

INTRODUCTION

Human retroviruses and the hepatitis B and C viruses (HBV and HCV, respectively) share routes of transmission; thus, coinfections occur and could alter subsequent disease outcomes. A preliminary study on human T-lymphotropic virus types 1 and 2 (HTLV-1/2) in serum samples from HBV- and HCV-infected individuals in São Paulo revealed 1.3% and 5.3% rates of coinfection, respectively. These percentages were of concern since they were detected in HTLV-endemic regions and in high-risk individuals in Brazil. The present study was conducted to extend and confirm these data.

METHODS

HTLV-1/2 and human immunodeficiency virus (HIV) infection status were identified in 1,984 sera for HBV and HCV viral load quantification - 1,290 samples from HBV-infected individuals (53.3% men, mean age: 47.1 years) and 694 samples from HCV-infected individuals (56.3% men, mean age: 50.1 years). HTLV-1/2 antibodies were detected by enzyme immunoassay, followed by western blotting and line immunoassay; HIV infection was detected by enzyme immunoassay.

RESULTS

HTLV-1/-2 infection was detected in 1.9% HBV-infected individuals (0.7% HTLV-1 and 1.2% HTLV-2) and in 4.0% (2.4% HTLV-1 and 1.6% HTLV-2) HCV-infected individuals; HIV infection was detected in 9.2% and 14.5%, respectively. Strong associations with HTLV and HIV, male sex, and older age were found in HBV/HTLV and HCV/HTLV-coinfected individuals (p<0.05).

CONCLUSIONS

HTLV-1 and HTLV-2 were confirmed to be prevalent in individuals with HBV and HCV in São Paulo; coinfected individuals deserve further clinical and laboratory investigation.

The prevalence and significance of HTLV-I/II seroindeterminate Western blot patterns

Human T-lymphotropic virus type I (HTLV-I) infects an estimated 15–20 million persons worldwide. A number of diseases have been associated with the virus including adult T-cell leukemia (ATL), HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP), HTLV-I uveitis, and HTLV-I-associated infective dermatitis. Once it was shown that there is an increased risk for developing HAM/TSP associated with blood transfusion, screening for HTLV-1 among blood banks was implemented in Japan, United States, France, and the Netherlands. This process includes detection by an enzyme immunoassay (EIA) followed by a confirmatory Western blot (WB) in which recombinant proteins specific for HTLV-I Env glycoproteins are incorporated into WB strips. HTLV-I seropositive results are defined by the presence of antibodies against either gp46 or gp62/68 (both Env protein bands) and either p19, p24, or p53 (one of the gag bands). HTLV-II seropositivity is confirmed by the presence of rgp46-II. However, numerous cases have been documented in which serum samples are reactive by EIA, but an incomplete banding pattern is displayed by subsequent confirmatory WB. Although the significance of these HTLV-I/II seroindeterminates is unclear, it may suggest a much higher incidence of exposure to HTLV-I/II than previously estimated.

[Investigation of anti-HTLV I/II seroprevalence in healthy blood donors in Izmir region, Turkey]

Almost 10-20 million people in the world are thought to be infected by human deltaretroviruses, namely human T-cell lymphotropic virus (HTLV) type I and II, recently. HTLV-I is endemic in southwestern Japan, the Caribbean and sub-Saharan Africa, whereas HTLV-II is more prevalent in intravenous drug addicts, and in American indian populations, endemically. HTLV-I is mainly responsible for adult T-cell leukemia (ATL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), however, HTLVII is not clearly associated with a known clinical disease. Both viruses may be transmitted by sexual contact, parenteral route, whole blood transfusion and breast-feeding. In most of the countries [USA, Canada, South America, Caribbean, Japan, Taiwan and some Europe countries (France, UK, Ireland, Sweden, Denmark, The Netherlands, Portugal, Romania, Greece)] routine screening of anti-HTLV-I/II in blood donors is mandatory, however, there is no such practice in Turkey since seroepidemiologic data on HTLVI/II infections is insufficient. In this study, the seroprevalence of HTLV-I/II in healthy blood donors admitted to the blood bank of Ege University Medical Faculty Hospital, Izmir (located at Aegean region), was investigated to support data on the decision making process on routine screening of anti-HTLV-I/II in blood centers. Serum samples from 10.000 healthy blood donors (mean age: 32.6 years; 87.8% were male), who succeeded the donor history questionnaire, were included to the study, and HTLV-I/II antibodies were screened by a commercial enzyme immunoassay (ELISA) (Murex HTLVI-II, Murex Diagnostics, UK) method. Serum samples which were yielded reactive and borderline results were retested by ELISA, and repeated reactive/borderline results were then confirmed by HTLV-I/II confirmation test (INNO-LIA HTLV-I/II, Innogenetics, Belgium). Seven samples yielded reactive/borderline reactive results by both ELISA lots, however, all of them were found negative by confirmatory test. According to our data HTLV-I/II infections are not endemic in Izmir region, and anti-HTLV-I/II screening of blood donors is not required in our blood center currently. Nevertheless, screening HIV which is very rare in prevalence among the donor population, is mandatory for blood donors in our country. Thus, even its prevalence is very low, much more comprehensive and multi-centered studies are necessary for making the decision of integrating HTLV-I/II in routine blood bank screening tests in Turkey.

Difficulties in the diagnosis of HTLV-2 infection in HIV/AIDS patients from Brazil: comparative performances of serologic and molecular assays, and detection of HTLV-2b subtype

The current diagnosis of human T-lymphotropic virus type-2 (HTLV-2) infection is based on the search of specific antibodies; nevertheless, several studies conducted in Brazil pointed deficiencies of the commercially available kits in detecting HTLV-2, mostly in HIV/AIDS patients. This study searched for the presence of HTLV-1 and -2 in 758 HIV/AIDS patients from Londrina, Paraná, Brazil. Serum samples were screened for HTLV-1/2 antibodies using two EIA kits (Vironostika and Murex), and confirmed by WB (HTLV Blot 2.4, Genelabs). The results obtained by EIA disclosed 49 (6.5%) reactive sera: 43 positive by both EIA kits, and six with discordant results. WB confirmed HTLV-1 infection in seven samples (0.9%) and HTLV-2 in 21 sera (2.8%). Negative and indeterminate results were detected in four (0.5%) and 16 (2.1%) sera, respectively. Blood from 47 out of 49 HTLV seroreactive patients were collected and analyzed for the presence of env, LTR and tax genomic segments of HTLVs by PCR. PCR confirmed six cases of HTLV-1 and 37 cases of HTLV-2 infection (14 out of 16 that were found to be WB indeterminate). Restriction analysis of the env PCR products of HTLV-2 disclosed 36 isolates of HTLV-2a/c subtype, and one of HTLV-2b subtype. These results emphasize the need of improving serologic tests for detecting truly HTLV-2 infected patients from Brazil, and confirm the presence of HTLV-2b subtype in the South of this country.

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.

High seroprevalence of anti-HTLV-I/II antibodies among solid organ donors necessitates confirmatory testing

BACKGROUND

Human T-cell lymphotrophic virus (HTLV) type I has been linked to adult T-cell leukemia/lymphoma (ATL) and HTLV-I associated myelopathy (HAM). Transmission of HTLV by blood and organ transplantation has been documented, with some infections leading to clinical disease. Organ donors are tested for anti-HTLV antibodies and donor suitability is determined primarily by results from enzyme immunoassays (EIA). Confirmatory testing is not routinely performed, and the number of false positive organ donors is unknown.

METHODS

In order to investigate the contemporary seroprevalence of anti-HTLV I/II antibodies among solid organ donors and determine the number of false positive samples, we tested 1,408 specimens from prospective organ donors in 2002 and 2003. All specimens were tested for anti-HTLV antibodies by a commercial EIA. Repeatedly reactive specimens underwent confirmatory testing using a commercial Western blot.

RESULTS

There were 22 repeatedly EIA reactive donor specimens (1.56%). Five specimens did not undergo further testing because of case shutdown or insufficient sample quantity. HTLV I/II western blot confirmed six positives, whereas five were negative and six were indeterminate. The majority of confirmed specimens were positive for antibodies to HTLV-II.

CONCLUSIONS

Our data shows that 29% of initially reactive specimens were false positives. With the increasing demand for organs, the unnecessary rejection of organs that are falsely positive for HTLV antibodies becomes of tremendous importance and stresses the need for timely confirmatory testing for HTLV.

Is seroprevalence of HTLV-I/II among blood donors in India relevant?

Human T-cell lymphotropic virus type I/II (HTLV-I/II) is associated with certain hematologic and neurologic disorders. Seroprevalence studies demonstrate that the distribution of HTLV-I/II is heterogeneous worldwide and not specific to one region. Because blood is one of the major routes of transmission of the virus, blood banks of several countries routinely screen all blood donations for HTLV-I/II. The aim of the present study was to assess the seroprevalence rate of HTLV-I/II antibodies among Indian blood donors and to confirm the positive rates by polymerase chain reaction (PCR). Between Jan 2004 to May 2005, consecutive blood samples of 10,000 blood donors were collected at the blood bank of Armed Forces Medical College, Pune. The samples were screened for HTLV-I/II by enzyme-linked immunosorbent assay (ELISA) method. Screening resulted in 18 (0.18%) positive samples, of which 14 (77.8%) samples were also positive by PCR. The prevalence of HTLV-I/II carriers in India seems to be negligible and is not a major public health hazard. Hence, routine screening of Indian blood donors for antibody to HTLV-I/II is not warranted due to its low prevalence in India.

Molecular evidence for infection by HTLV-2 among individuals with negative serological screening tests for HTLV antibodies

Previous serological studies on the Arara do Laranjal Indian group revealed extensive HTLV-2 infections. A collection of 97 new samples from the Arara were found repeatedly negative using three different commercial enzyme immunoassays. Eight samples that exhibited optical density readings close to the cut-off value were re-evaluated using Western blot (GeneLab 2.4, Singapore) assay. One sample was found to be non-reactive, five exhibited indeterminate patterns, one was classified as HTLV, and one was confirmed as HTLV-2. Peripheral blood mononuclear cell DNA of the eight samples were subjected to nested PCR and restriction fragment length polymorphism (RFLP) analysis of the pX and env regions, and nucleotide sequencing of the 5'-LTR region. All produced amplification products of pX, but env could be amplified in only one sample with the commonly used primers. RFLP analysis of the pX region using TaqI confirmed HTLV-2 infection. Nucleotide sequencing of the 5'-LTR region was performed in three samples (HTLV-2, HTLV and indeterminate based on Western blot pattern). Phylogenetic analysis of a 449-nt fragment using the Neighbour-Joining method clearly demonstrated that the three samples clustered within the HTLV-2c molecular subtype. The present study confirms the wide dissemination of the HTLV-2c subtype among linguistically and culturally distinct Amazonian Indian groups, and emphasizes the unique occurrence of infection by this subtype in Brazil. Moreover, it emphasizes the limitation of employing the present serological screening assays in blood banks, epidemiological studies, and the importance of molecular assays in the confirmatory procedures for the primary detection of HTLV-2 infections.

Effectiveness of human T-lymphotropic virus (HTLV) recipient tracing (lookback) and the current HTLV-I and -II confirmatory algorithm, 1999 to 2004

BACKGROUND

This study reports on the efficacy of an investigational human T-lymphotropic virus (HTLV)-I and -II lookback program in the context of differing confirmatory testing algorithms.

STUDY DESIGN AND METHODS

The results of testing approximately 35 million donations for anti-HTLV-I and -II were evaluated for two recent periods reflecting the use of two different confirmatory algorithms. The number of seroconverting donors was established for the entire period, and the results of lookback on their prior donations were investigated.

RESULTS

The dual enzyme immunoassay (EIA) strategy was used throughout both study periods and resulted in a 57 to 76 percent reduction in the number of samples requiring confirmatory testing. From May 2000 to February 2002, a total of 9138 samples were repeatedly reactive by the primary screening test; of the concordant EIA-reactive samples, 461 (12%) were confirmed by Western blot, whereas 3083 (79%) were indeterminate. From March 2002 to December 2004, a total of 21,291 samples were repeatedly reactive; of the concordant EIA-reactive samples, 1099 (22%) were confirmed by the State of California's reference laboratory and only 273 (5%) were equivocal. Overall, 38 or 1 in 921,000 donations were from a seroconverting donor with 32 prior donations within the lookback period. Of those 32, components from only 11 were transfused to recipients who survived; of these, 4 were tested and all were nonreactive for HTLV-I and -II antibodies.

CONCLUSION

Use of creative algorithms can increase the efficacy of anti-HTLV-I and -II confirmatory testing and reduce the number of indeterminate results. Currently, lookback for HTLV-I and -II has a very low yield, and its public health benefit is questionable.

HTLV infection among young injection and non-injection heroin users in Spain: Prevalence and correlates

BACKGROUND

Although some studies have described the epidemiology of infection with HIV or hepatitis B and C in young users in Spain - one of the European countries with the highest prevalences - there are no studies of the prevalence of HTLV infection and the most important associated factors.

OBJECTIVES

To evaluate the prevalence and main determinants of HTLV-1 and HTLV-2 infection in young heroin users (including both injection (IDUs) and non-injection drug users (NIDUs)) recruited outside health care services in three of Spain's principal cities.

STUDY DESIGN

Cross-sectional cohort study. All participants (981) were street-recruited by chain referral procedures between April 2001 and December 2003. Face-to-face interviews were conducted using a structured questionnaire and dried blood spot samples were collected for serological testing.

RESULTS

No sample was positive for HTLV-1 and 27 samples were positive for HTLV-2; all of these were found only in Spanish IDUs in the cities of Madrid (17, 6.2%) and Barcelona (10, 3.5%). The only two factors significantly associated with HTLV infection in the logistic regression analysis were HIV infection (OR 5.7; 95% CI 2.2-14.8) and having injected in the last 30 days (OR 6.5; 95% CI 1.4-29.8). Having been in prison (OR 2.4; 95% CI 0.9-6.4) and HCV infection (OR 3.8; 95% CI 0.5-30.7), which were strongly and significantly associated in the bivariate analysis, were no longer significant in the logistic analysis. Almost the same variables were selected in the tree analysis, in which subjects could be classified into three groups: high prevalence (28.5%, HIV+ and HBV+ who had injected in the last 30 days), medium prevalence (17.8%) and low (<3%) or zero prevalence (HIV-, HCV- and HBV-).

CONCLUSIONS

HTLV-1 was not detected among young Spanish heroin users. HTLV-2 was not found in NIDUs (perhaps due to the low rate of sexual transmission); it was found only in IDUs from Madrid and Barcelona, but not in those from Seville. Its prevalence is very low and the main correlates of infection were HIV infection and injection as the usual route of heroin administration.

Human T Lymphotropic Virus Types I and II Western Blot Seroindeterminate Status and Its Association with Exposure to Prototype HTLV‐I

Human T lymphotropic virus types I and II (HTLV-I/II) Western blot (WB) seroindeterminate status, which is defined as an incomplete banding pattern of HTLV protein Gag (p19 or p24) or Env (GD21 or rgp46), is commonly observed. To investigate the significance of this finding, we examined HTLV-I/II serostatus and HTLV-I proviral load in 2 groups of individuals with WB seroindeterminate status. Low proviral loads were detected in 42% of patients with neurologic symptoms and 44% of voluntary blood donors. These data suggest that a subset of WB seroindeterminate individuals may be infected with prototype HTLV-I. To confirm this hypothesis, we evaluated HTLV-I/II serostatus and proviral load in prospectively collected specimens from 66 WB seronegative patients who had received HTLV-I-infected blood products by transfusion. Eight individuals developed WB seroindeterminate profiles after the transfusion. In addition, using a human leukocyte antigen type A*201-restricted HTLV-I Tax11-19 tetramer, we detected virus-specific CD8(+) T cells in peripheral blood mononuclear cells from WB seroindeterminate patients. These CD8(+) T cells were effective at targeting HTLV-I-infected cells. Collectively, the results suggest that HTLV-I/II WB seroindeterminate status may reflect a history of HTLV-I exposure. Our findings warrant further investigation of the possible clinical outcomes associated with WB seroindeterminate status.

Human T-cell lymphotropic virus type II in Guaraní Indians, Southern Brazil

Human T-cell lymphotropic virus type II (HTLV-II) is found in many New World Indian groups on the American continent. In Brazil, HTLV-II has been found among urban residents and Indians in the Amazon region, in the North. Guaraní Indians in the South of Brazil were studied for HTLV-I/II infection. Among 52 individuals, three (5.76%) showed positive anti-HTLV-II antibodies (enzyme-linked immunosorbent assay and Western blot). This preliminary report is the first seroepidemiological study showing HTLV-II infection among Indians in the South of Brazil.

Human T-cell lymphotropic virus types I and II (HTLV-I and -II) infection among seroindeterminate cases in Argentina

Human T-cell lymphotropic virus (HTLV) seroindeterminate cases have been reported among blood donors (BD) and in at-risk populations worldwide, including Argentina. The objective of the present work was to study the presence of HTLV-I/II infection and its association to specific Western blot (WB) patterns among healthy BD and at-risk populations in Argentina. We analyzed 83 HTLV-I/II seroindeterminate WB cases diagnosed among BD (n = 49) and in different at-risk populations (n = 34) for human retroviruses infections. Multiple indeterminate WB patterns were observed. Out of the total, 13.2% (11/83) of the cases were found to be HTLV-I/II positive by nested-PCR (n-PCR), including 13.2% (11/83) HTLV-I and 2.4% (2/83) presenting HTLV-I and -II co-infection. Most of their serological profiles showed reactivity to gag or env codified proteins. Two samples amplified only one of the six analyzed genes (1 HTLV-I pol gene and 1 HTLV-II tax gene). There was no association between the presence of Trypanosoma cruzi infection and an HTLV-I/II indeterminate WB pattern (only 3 of the 83 samples were positive for T. cruzi antibodies). In conclusion, the majority of HTLV-seroindeterminate WB donors lacked HTLV provirus and was thus considered uninfected. However, when seroreactivity to Env and Gag proteins are observed on the WB and especially in at-risk populations, HTLV infection should be suspected; such individuals should be followed-up and retested.

Molecular characterization of human T-cell lymphotropic virus type 2 (HTLV-II) from people living in urban areas of Sao Paulo city: Evidence of multiple subtypes circulation

BACKGROUND

In Brazil, human T-cell lymphotropic virus type I and type II (HTLV-I and HTLV-II) are co-circulating and possess approximately 65% homology, which results in high cross-reactivity in serological tests. Based on the detection of EIA and Western blot (WB) tests, HTLV serodiagnosis yields indeterminate results in high-risk population, with the true determination of HTLV-II prevalence requiring a combined serological and molecular analysis. Molecular analysis of HTLV-II isolates has shown the existence of four distinct subtypes: IIa, IIb, IIc, and IId. The aim of this study was to evaluate the routine EIA and WB used in Sao Paulo city, as well as molecular methods for confirmation of infection and HTLV-II subtype distribution.

RESULTS

Two hundred ninety-three individuals, who were enrolled in the HTLV out-clinic in Sao Paulo city, Brazil, between July 1997 and May 2003, were tested by EIAs, and positive sera 232 (79%) reactive by one of the tests. When these sera were tested by WB revealed 134 were HTLV-I, 28 HTLV-II, 4 HTLV-I/II, and 48 were indeterminate. Polymerase chain reaction (PCR) on the indeterminate group showed that 20 (42%) were HTLV-II and 28 were negative. From a total of 48 HTLV-II subjects with DNA available, restriction fragment length polymorphism (RFLP) of the env region revealed 47 HTLV-IIa and 1 HTLV-IIb. The phylogenetic analysis was performed on 23 samples, which identified 19 as subtype a, Brazilian subcluster, and 4 as subtype b. This is the first time HTLV-II subtype b has been described in Brazil. However, further studies, such as a complete nucleotide DNA sequencing, need to be done to confirm these findings.

HTLV-2 horizontal and vertical transmission in a family from a Brazilian urban area: seroepidemiological, clinical and molecular study

Human T cell lymphotropic virus type 2 (HTLV-2) has been shown to be endemic in Brazilian Indians and among intravenous drug users in urban areas, but transmission of this infection seems to be infrequent in the general population living in urban areas in Brazil. Six persons in three generations of a Brazilian family were evaluated to assess HTLV-2 transmission and its molecular features in the positive cases. The index was detected during screening (HTLV EIA) of donated blood in Fundação Hemominas, Belo Horizonte, Brazil. Confirmatory serological test and viral typing were performed by Western blotting and polymerase chain reaction. The family consisted of husband, wife (index case), three daughters, and the mother of the index case. The husband and one daughter were found positive, thus pointing to horizontal and vertical transmission. The husband was a truck driver, who reported casual sex during frequent traveling. The positive daughter was breast-fed for 3 months, as opposed to the remaining two (seronegative), who breast-fed for 1 month. The index case's mother was negative. To identify HTLV-2 subtype(s), phylogenetic analysis of the noncoding long terminal repeat region and part of the env and tax coding regions was performed. These new isolates from Belo Horizonte are related to subtype IIa but present a molecular variant with extended tax, previously reported in subtype IIc. Analyzing both LTR and env regions, the family's sequences clustered with isolates of Brazilian intravenous drug users and transfusion transmitted virus.

Seroprevalence of Human T Cell Leukemia Virus in HIV Antibody-Negative Populations in Rural Cameroon

Seven hundred forty-seven serum samples collected from humans in 4 separate rural village areas in Cameroon were examined for antibody to human T cell leukemia viruses (HTLVs) by use of an enzyme immunoassay followed by a Western blot assay. Of the 88 serum samples that the enzyme immunoassay found to be repeatedly reactive, the HTLV status of 49 samples was confirmed by Western blot assay to be HTLV type I, and the status of 6 samples was confirmed to be HTLV type II.

Heterogeneous geographic distribution of human T-cell lymphotropic viruses I and II (HTLV-I/II): serological screening prevalence rates in blood donors from large urban areas in Brazil

Brazil may have the highest absolute number of HTLV-I/II seropositive individuals in the world. Screening potential blood donors for HTLV-I/II is mandatory in Brazil. The public blood center network accounts for about 80.0% of all blood collected. We conducted a cross-sectional study to assess the geographic distribution of HTLV-I/II serological screening prevalence rates in blood donors from 27 large urban areas in the various States of Brazil, from 1995 to 2000. Enzyme immunoassay (EIA) was used to test for HTLV-I/II. The mean prevalence rates ranged from 0.4/1,000 in Florianopolis, capital of Santa Catarina State, in the South, to 10.0/1,000 in São Luiz, Maranhão State, in the Northeast. EIA prevalence rates are lower in the South and higher in the North and Northeast. The reasons for such heterogeneity may be multiple and need further studies.

Prevalence and molecular characterization of human T cell leukemia virus type 2 in a group of intravenous drug users coinfected with HIV type 1 in Portugal

Human T cell lymphotropic virus type 2 infections can be found in the large urban areas of the United States and Europe, where Spain and Italy are the most affected countries. The population most affected by the epidemic is characterized by high-risk behavior groups, mainly the sharing of needles between intravenous drug users (IDUs) with contaminated cellular blood products. It is also described that HTLV-2 infection appears as a coinfection with HIV-1. We have selected samples corresponding to 583 IDUs infected with HIV and screened for the presence of HTLV-1/2 antibodies. We have performed the molecular characterization of HTLV-2 in three confirmed positive cases on the basis of the long terminal repeat region. We can observe the Portuguese sequences (PortHl, PortNn, and PortVs) in the HTLV-2b cluster, grouping with the Spanish sequences, showing close phylogenetic relatedness. We may assume that HTLV-2 infection was introduced in Portugal from Spain. These results update previous reports that mentioned Portugal as being free of HTLV- 2 infections, and allow the identification of the subtype that is present, giving a first-hand description of the prevalence of HTLV-2 infection in a particular high-risk behavior group and justifying the importance of epidemiological surveillance in order to prevent dissemination of the infection.

Low prevalence of antibodies to human T-lymphotropic virus-I/II among blood donors in eastern Saudi Arabia

The seroprevalence of human T-lymphotropic virus (HTLV)-I/II was assessed in 13,443 consecutive blood donors in eastern Saudi Arabia between 1998 and 2001. Screening by enzyme-linked immunosorbent assay (ELISA) and confirmation by Western blot resulted in 8 (0.060%) positive cases, of which 5 (0.056%) belonged to Saudi and 3 (0.113%) to non-Saudi donors. The majority of the HTLV-positive donations (6/8) were for patients, and none had a history of known risk factor for HTLV-I/II transmission. Although the very low prevalence of HTLV-I/II among Saudi donors does not support routine screening, screening of donors from other nationalities may be initiated, especially those from HTLV-I/II endemic areas.

The seroepidemiology of human T-lymphotropic viruses: types I and II in Europe: a prospective study of pregnant women

BACKGROUND

Up to 20 million persons are infected with the human retroviruses human T-lymphotropic virus (HTLV)-I and HTLV-II globally. Most data on the seroprevalence of HTLV-I and HTLV-II in Europe are from studies of low-risk blood donors or high-risk injection drug users (IDUs). Little is known about the general population.

METHODS

A prospective anonymous study of HTLV-I and HTLV-II seroprevalence among 234,078 pregnant women in Belgium, France, Germany, Italy, Portugal, Spain, and the United Kingdom was conducted. Maternal antibody status was determined by standard methods using sera obtained for routine antenatal infection screens or eluted from infant heel prick dried blood spots obtained for routine neonatal metabolic screens.

RESULTS

Anti-HTLV-I/II antibodies were detected and confirmed in 96 pregnant women (4.4 per 10,000, 95% confidence interval [CI]: 3.5-5.2). Of these, 73 were anti-HTLV-I, 17 were anti-HTLV-II, and 6 were specifically anti-HTLV but untyped. The seroprevalence ranged from 0.7 per 10,000 in Germany to 11.5 per 10,000 in France.

CONCLUSIONS

Pregnant women better reflect the general population than blood donors or IDUs. The seroprevalence of HTLV-I and HTLV-II in Western Europe is 6-fold higher among pregnant women (4.4 per 10,000) than among blood donors (0.07 per 10,000). These data provide a robust baseline against which changes in HTLV-I and HTLV-II seroprevalence in Europe can be measured.

Serologial screening of human T cell lymphotropic virus I and II (HTLV I/II) in blood banks by immunoblotting and enzyme-immuno assays: to demand or to defeat?

Human T cell lymphotropic virus I and II (HTLV I/II) has been recommended to be screened for blood donors since 1988, and it become a mandatory test to get college of american Pathologists (CAP) accreditation. The present study aimed at investigating the prevalence rate of HTLV I/II among Arab blood donors, to revise whether is its screening mandatory? Thirty-thousand (30,000) Arab donors along two years attending two central hospital blood banks in Jeddah. Antibodies to HTLV I/II have been screened using enzyme immunoassay (E.I.A) and immunoblotting assay (Western blot). Results revealed zero prevalence rate. Based upon this finding, no potential risk of HTLV I/II transmission among blood donors population exist. As screening for HTLV I/II is still mandatory, it could be done on pools of sera rather than on individual serum samples, after standardization of a pooling protocol, to fulfill coast-effectiveness and reduce the coasts by 90-95%.

High prevalence of HTLV-I and HTLV-II among blood donors in Argentina: a South American health concern

After an HTLV-I endemic area was discovered in Jujuy, a northwestern province in Argentina, to detect other possible foci of HTLV-I/II we started in 1997 a multicentric study to estimate the seroprevalence of HTLV-I/II including blood banks from different regions of the country. Out of 123,233 samples from nine different provinces, 68 proved seropositive with a final prevalence of 0.05% (95% CI = 0.0432-0.0704%). The seroprevalence ranged from 0.03 to 0.16% depending on the geographic location. An HTLV-I [odds ratio (OR) 12.7, 95% confidence interval (CI), 3.43-47.60] prevalence significantly greater was found in the northwest (Salta Province) and a nonsignificant but higher prevalence of HTLV-II in the North (Chaco). Two (0.001%) of the seropositive blood donors reported risk factors due to receiving transfusions and 19 (0.01%) were born in HTLV-I/II South American endemic areas. Although Argentina has been considered a nonendemic country for HTLV-I/II, the need for systematic screening for such infection became imperative based on the present study.

Antigenic mixture of synthetic peptides for the immunodiagnosis of HTLV I/II infection

Monomeric and chimeric synthetic peptides were used as coating antigens in four different mixtures in a solid phase immunoassay to select an optimal combination for the detection of antibodies to human T-cell lymphotropic virus (HTLV) in serum samples. The peptides, P-13 (gp21 I), Q5 (gp21 II)-GG-(gp46 II), and Q (gp46 I)-GG-(p19 I), represent immunodominant sequences from transmembrane protein (gp21), envelope protein (gp46), and core protein (p19) of HTLV I/II viruses; they were the most antigenic and specific peptides in previous studies. The sequences of the chimeric peptides were separated by two glycine residues. An indirect UltramicroEnzyme-linked immunosorbent assay (UMELISA) was used to evaluate the antigenicity of these peptide mixtures by using samples from anti-HTLV I/II PRP205(M), (n = 20), HTLV I-infected individuals from Cuba (n = 7), and HTLV I-positive sera from Colombia and Chile (n = 9). The specificity was evaluated with healthy blood donor sera (n = 300), anti-HIV 1-positive samples (n = 10), and other seropositive samples to different infectious agents. The highest sensitivity and specificity was obtained with mixture 1, which could be very useful in the immunodiagnostic of HTLV infection.

[Sero-epidemiological study on the human T-cell leukaemia virus type I/II infection in the east coastal areas of Fujian province]

OBJECTIVE

To study the seroprevalence of human T-cell leukaemia virus type I/II (HTLV-I/II) infection in adult population in the east coastal areas of Fujian and to explore the possible risk factors of HTLV-I/II.

METHODS

A total number of 3259 blood samples from drug users, sexually transmitted disease (STD) patients, prostitutes and blood donors for serologic assays during 1999 to 2002, were collected. All samples were screened for HTLV-I/II antibody, using enzyme linked immunosorbent assay (ELISA) kits. All of the positive samples were confirmed by western blot (WB) kits. Statistical analysis was done by Epi software, and chi(2) test by Fisher's exact test. P value < 0.05 was considered statistically significant.

RESULTS

The overall seroprevalence rate of HTLV-I/II in healthy populations was 0.06% including, 0.32% in drug users, 0.58% in STD patients and prostitutes respectively. HTLV-II had not been found. The seropositive rates for HTLV-I in STD patients and prostitutes were significantly higher than the findings among healthy populations (P < 0.05). There were no different seroprevalence rates between drug users and healthy populations (P > 0.05). No significant changes in HTLV-I prevalence rates were found in the different age groups as well as in Fuzhou and Linde cities (P > 0.05).

CONCLUSION

The result suggested that in the east coastal areas of Fujian province, HTLV-I was the main prevalent virus. The seroprevalence of HTLV-I was very low, with no HTLV-II. Neither age nor gender seemed to be HTLV-I risk factor in the east coastal areas of Fujian province, but the increase of exposure to sex might be one.

Human T lymphotropic virus types I and II proviral sequences in Argentinian blood donors with indeterminate Western blot patterns

Human T-cell lymphotropic virus (HTLV) seroindeterminate blood donors have been reported worldwide including Argentina. To investigate the significance of HTLV-I/II seroindeterminate Western blot (WB) patterns, we conducted an 8-year cross-sectional study. Of 86,238 Argentinian blood donors, 146 sera were reactive by screening tests. The WB results indicated that 20% were HTLV-I reactive, 8% HTLV-II reactive, 61% indeterminate, and 11% negative. The overall seroprevalence was 0.034% for HTLV-I, 0.014% for HTLV-II, and 0.103% for indeterminate. In 57 reactive specimens, HTLV-I/II provirus could be examined by type specific PCR for tax, pol, and env regions. When at least two gene fragments were amplified HTLV-I/II infection was considered confirmed. PCR results confirmed all WB seropositive samples for HTLV-I (n = 15), and HTLV-II (n = 7), and the only WB negative case was also PCR negative, showing a complete concordance between PCR and WB. However, of 34 WB seroindeterminate sera studied by PCR, in 5 was proviral DNA amplified. According to our criteria PCR confirmed one to be HTLV-I, and one HTLV-II, 3 remained indeterminate since only tax sequences were amplified. Among WB indeterminate samples tested by PCR, most of their serological profile showed reactivity to gag codified proteins but lacked env reactivities (70%). One sample with a WB gag pattern showed proviral tax sequences, but of the four samples with reactivity to env proteins GD21 (n = 3) or rgp46II (n = 1) PCR results indicated that one was HTLV-I, one was HTLV-II, and two were indeterminate (only tax sequences). In conclusion, the majority of HTLV-seroindeterminate WB donors exhibited a gag indeterminate profile lacking HTLV provirus, and were thus considered uninfected. However, seroreactivity to env proteins, in particular to GD21, may indicate infection and a follow-up study of each seroreactive blood donor should be considered.

Post-transplantation HTLV-1 myelopathy in three recipients from a single donor

OBJECTIVES

This paper reports for the first time three cases of infection by HTLV-I via organ transplantation; all the organs coming from the same asymptomatic infected donor. The need is considered for the implementation of compulsory screenings for HTLV antibodies on organ donors and on blood banks.

METHODS

The determination of antibodies for HTLV-I/II on samples of serum and cerebral spinal fluid from the patients and the donor was performed by enzyme immunoassay and western blot. Analysis of proviral DNA was performed by polymerase chain reaction. To detect changes in the sequence of amino acids, the tax gene was sequentiated, amplified, and compared with ATK prototype stocks. Spinal cord magnetic resonance imaging, cerebral spinal fluid, and somatosensory evoked potential studies were carried out in all patients.

RESULTS

All three transplanted patients developed a myelopathy within a very short period of time. In all three patients and donor the virus belonged to the Cosmopolitan A subtype. The homology of HTLV-I sequences recovered from the patients and donor was 100% in all four cases. Proviral load was high in all three patients. The factors that certainly contributed to the infection in the first place, and the development of the disease later, were on the one hand the high proviral load and their immunosuppressed condition, and on the other the virus genotype, which proved to be an aggressive variant. However, the analysis of the histocompatibility antigen showed that two of the patients carried an haplotype that has been associated with a lower risk of developing this disease.

CONCLUSIONS

It is argued that, although in Spain and other European countries there is not compulsory screening for HTLV antibodies because of the studies that show a low seroprevalence, in view of the cases here reported, and to avoid the serious consequences that such infection has on transplanted patients, compulsory screenings, both on organ donors and on blood banks, should be implemented.

Detection of human T-lymphotropic virus (HTLV) tax sequences in New York City blood donors seronegative for HTLV types 1 and 2

A potential public health concern is the reported detection of the human T-lymphotropic virus (HTLV) tax gene in the lymphocytes of up to 11% of a low-risk group of New York City blood donors (NYBD). This study aimed to independently confirm the prevalence of HTLV tax sequences in 293 NYBD. All NYBD tested negative for antibodies to HTLV types 1 and 2 and HTLV Tax. HTLV tax sequences were not detected in the NYBD lymphocytes. These data demonstrate the lack of HTLV-1 tax in this group of NYBD at low risk for HTLV infection.

Evaluation of surrogate markers for human immunodeficiency virus infection among blood donors at the blood bank of "Hospital Universitário Regional Norte do Paraná", Londrina, PR, Brazil

This study evaluated the usefulness of the anti-HBc, hepatitis C virus antibodies (anti-HCV), human T cell lymphotropic virus I and II antibodies (anti-HTLV I/II), serologic tests for syphilis, and surface antigen of hepatitis B virus (HBsAg) as surrogate markers for the risk for HIV infection in 80,284 serum samples from blood donors from the Blood Bank of "Hospital Universitário Regional Norte do Paraná", Londrina, Paraná State, Brazil, analyzed from July 1994 to April 2001. Among 39 blood donors with positive serology for HIV, 12 (30.8%) were anti-HBc positive, 10 (25.6%) for anti-HCV, 1 (2.6%) for anti-HTLV I/I, 1 (2.6%) was positive for syphilis, and 1 (2.6%) for HBsAg. Among the donors with negative serology for HIV, these markers were detected in 8,407 (10.5%), 441 (0.5%), 189 (0.2%), 464 (0.6%), and 473 (0.6%) samples, respectively. The difference was statistically significant (p < 0.001) for anti-HBc and anti-HCV. Although the predictive positive values for these surrogate markers were low for HIV infection, the results confirmed the anti-HBc and anti-HCV as useful surrogate markers for HIV infection thus reinforcing the maintenance of them in the screening for blood donors contributing to the prevention of the small number of cases in which HIV is still transmitted by transfusion.

Unusually high incidence of positive HTLV I/II results among young female organ donors in the peripartum period

HTLV I and II are unusual retroviruses associated with multiple neurologic and hematologic disorders. We observed an unusually high incidence of HTLV I-II seropositivity among young and middle-aged female organ donors, especially among those in the peripartum period. Ethical issues may arise when informing the families as well as when deciding whether to use organs from these donors. Further confirmatory tests may be difficult to obtain because of time and economic constraints associated with organ procurement.

[The prevalence of serum IgG antibodies against HTLV viruses type I and II in sarcoidosis patients]

The pathogenesis of sarcoidosis remains still unknown. Among numerous factors viruses are considered as potential causes. The aim of the study was investigation of human T-cell lymphotopic virus type I (HTLV-I) in sarcoidosis patients. Studied group (I) consisted of 52 patients: 29 women and 23 men aged from 24 to 62 years; mean age 40 years. The diagnosis of sarcoidosis was confirmed by histologic examination in 46 patients and on the base of clinical, HRCT--chest scan and BAL findings in 6 patients. Control group (II) consisted of 92 various pulmonary disorders patients and healthy subjects in the aged from 20 to 83 years; mean age 54 years. In both groups the ELISA test detecting antibodies against HTLV-I/II was performed with the use the diagnostic kit produced by Organon Teknika, Belgium. Results were interpreted by measuring the optical density (OD). The cut-off point 0.386 was established according to the rule defined by kit's producent. The values of OD ranged in group I from 0.061 to 0.384 and in group II from 0.047 to 0.213; thus, no positive results of the test were observed. The values of OD did not differ significantly in both groups (p = 0.59).

CONCLUSION

In our region the participation of HTLV-I in the pathogenesis of sarcoidosis is doubtful.

Strategies for diagnosis of HTLV-I and -II

BACKGROUND

No gold standard exists for diagnosis of HTLV infection. The aim of thus study was to compare the accuracy of a combination of two sensitive ELISAs with Western blot (WB), a line immunoassay, and PCR for diagnosis of HTLV infection.

STUDY DESIGN AND METHODS

Nine hundred eighty-five specimens were tested for the presence of HTLV antibodies by HTLV-I and/or HTLV-II EIAs (Murex and Ortho), WB (Diagnostic Biotechnology), line immunoassay (INNO-LIA, Innogenetics), and/or presence of HTLV DNA by PCR. The results were compared with the probable HTLV infection status of each subject, as determined by detailed review of all available laboratory, clinical, and epidemiologic data.

RESULTS

The sensitivity for diagnosis of HTLV-I infection was high for all assays evaluated, but both PCR and WB had a lower sensitivity rate (approx., 80%) for confirmation of HTLV-II. INNO-LIA detected 94 percent of the HTLV-II-positive samples. However, Murex EIA in combination with Ortho EIA was 100-percent sensitive for the detection of both HTLV-I and HTLV-II antibodies. Furthermore, the number of samples giving indeterminate results in the ELISA combination was much lower as compared with WB (2.5% vs. 50%).

CONCLUSION

Based on these findings, a new, more sensitive and specific test strategy for HTLV diagnosis than the current algorithm, which includes WB, is proposed. Thereby, both the direct and indirect costs can be substantially reduced.

[Absence of HTLV-I/II virus circulation in blood donors from the provinces of Santa Fe and Santiago del Estero]

In the present study, we evaluated the seroprevalence of HTLV-I/II infection among the blood donors in Santa Fe and Santiago del Estero provinces. A total of 1327 serum samples from blood donors from Rafaela blood bank of Santa Fe province and 3382 serum samples from blood donors from Dr Edgar Bouzon blood bank of Santiago del Estero province were studied. The antibody screening was done by particle agglutination assay (PA) (SERODIA, Fujirebio Inc., Tokyo, Japan) or by enzyme immuno assay (EIA) (Abbott HTLV-I/HTLV-II EIA, Abbott, Germany). The "in house" indirect immunofluorescence assay (IFA) and Western blot (Bioblot HTLV Biokit, Barcelona, Spain) were used as confirmatory assays. All the samples resulted negative for specific antibodies against HTLV-I/II. These results suggest that HTLV-I/II are not circulating in low risk populations in these provinces or that the prevalences of infection would be lower than that reported by blood banks in other provinces of Argentina.

High prevalence of simian T-lymphotropic virus type L in wild ethiopian baboons

Simian T-cell leukemia viruses (STLVs) are the simian counterparts of human T-cell leukemia viruses (HTLVs). A novel, divergent type of STLV (STLV-L) from captive baboons was reported in 1994, but its natural prevalence remained unclear. We investigated the prevalence of STLV-L in 519 blood samples from wild-living nonhuman primates in Ethiopia. Seropositive monkeys having cross-reactive antibodies against HTLV were found among 22 out of 40 hamadryas baboons, 8 of 96 anubis baboons, 24 of 50 baboons that are hybrids between hamadryas and anubis baboons, and 41 of 177 grivet monkeys, but not in 156 gelada baboons. A Western blotting assay showed that sera obtained from seropositive hamadryas and hybrid baboons exhibited STLV-L-like reactivity. A PCR assay successfully amplified STLV sequences, which were subsequently sequenced and confirmed as being closely related to STLV-L. Surprisingly, further PCR showed that nearly half of the hamadryas (20 out of 40) and hybrid (19 out of 50) baboons had STLV-L DNA sequences. In contrast, most of the seropositive anubis baboons and grivet monkeys carried typical STLV-1 but not STLV-L. These observations demonstrate that STLV-L naturally prevails among hamadryas and hybrid baboons at significantly high rates. STLV-1 and -2, the close relative of STLV-L, are believed to have jumped across simian-human barriers, which resulted in widespread infection of HTLV-1 and -2. Further studies are required to know if STLV-L is spreading into human populations.

Chimeric synthetic peptides from the envelope (gp46) and the transmembrane (gp21) glycoproteins for the detection of antibodies to human T-cell leukemia virus type II

Two chimeric synthetic peptides incorporating immunodominant sequences from HTLV-II virus were synthesized. Monomeric peptides P2 and P3 represent sequences from transmembrane protein (gp21) and envelope protein (gp46) of the virus. The peptide P2 is a gp21 (370-396) sequence and the peptide P3 is a gp46 (178-205) sequence. Those peptides were arranged in a way that permits one to obtain different combinations of chimeric peptides (P2-GG-P3 and P3-GG-P2), separated by two glycine residues as spacer arms. The antigenic activity of these peptides was evaluated by UltramicroEnzyme-linked immunosorbent assay (UMELISA) by using panels anti-HTLV-II-positive sera (n = 11), anti-HTLV-I/II-positive sera (n = 2), HTLV-positive (untypeable) serum samples (n = 2), and anti-HTLV-I-positive sera (n = 22), while specificity was evaluated with anti-HIV-positive samples (n = 19) and samples from healthy blood donors (n = 30). The efficacy of the chimeric peptides in solid-phase immunoassays was compared with the monomeric peptides and a mixture of the monomeric peptides. Higher sensitivity was observed for chimeric peptide Q5 assay. Those results may be related to a higher peptide adsorption capacity to the solid surface and for epitope accessibility to the antibodies. This chimeric peptide would be very useful for HTLV-II diagnostic.

Immunofluorescence assay reactivity patterns of serum samples presenting indeterminate Western blot results for antibodies to HIV-1 and HTLV-I/II in Cordoba, Argentina

Serum samples (n: 110) from blood donors and high risk individuals from Cordoba, Argentina with indeterminate HIV-1 and HTLV-I/II Wb profiles were studied for specific antibodies to HTLV-I/II and HIV-1 by indirect immunofluorescence assay (IFA) and for the presence or absence of HIV-1 and HTLV-I/II specific bands by Wb. This study was carried out in order to characterize their putative reactions with HIV-1 and HTLV-I/II proteins and to resolve the retrovirus infection status of these individuals. Results indicated that blood donors sera displaying indeterminate HIV-1 or HTLV-I/II Wb patterns were not immunoreactive to HTLV-I/II and HIV-1 on IFA. However, a high rate of indeterminate HIV-1 and HTLV-I/II Wb samples from high risk individuals had positive HTLV-I/II and HIV-1 IFA results respectively. Our study supports the growing evidence that HTLV-HIV indeterminate seroreactivity in low risk population is due to a cross reaction against nonviral antigens, and in high risk populations the indeterminate samples show serological cross-recognition between HIV-1 proteins and HTLV-I/II proteins on Wb. These results point out the necessity to investigate the HTLV-I/II reactivity in indeterminate HIV-1 samples and vice versa in order to confirm the diagnosis. Finally, this study shows the potential usefulness of IFA in elucidating the status of HIV-1 and HTLV-I/II infection of individuals with indeterminate Wb profiles, thus enabling resolution of retrovirus infection status.

[HTLV-I/II seroprevalence and risk factors associated with infection in a blood donor population in Córdoba, Argentina]

In this study we have determined the seroprevalence of infections by HTLV-I/II in the blood donor population from the city of Córdoba. A total of 5476 blood donor sera were screened for HTLV-I/II antibodies by particle agglutination assay (PA) (SERODIA HTLV-I, Fujirebio INC, Tokyo, Japan). The reactive sera samples were confirmed by an "in house" indirect immunofluorescence assay (IFA). 14 out of 5476 blood donors studied were PA reactive and were confirmed positive by IFA, showing a prevalence of 0.26% (95% confidence interval: 0.126%-0.394%). All the positive samples, except one, met the criteria for HTLV-I. Although one HTLV-I infected donor was an intravenous drug abuser and two donors were born in highly endemic areas for HTLV-I, no specific risk factors were identified among the others. The demonstration that HTLV-I circulates in blood donor population of Córdoba, points out that the systematic screening of blood for HTLV-I/II antibodies must be implemented in the blood banks, in an attempt to prevent the spread of infections with this oncogenic virus in Argentina.

[Screening of donor blood for viral markers. Anti-HIV, HBsAg and anti-HTLV-I/II in Denmark 1990-1999]

INTRODUCTION

We describe the results of donor blood screening in Denmark for anti-HIV-1/2 in the period 1990-1999 and for anti-HCV, HBsAg, and anti-HTLV-I/II in the period 1994-1999.

METHODS

Danish blood banks report the results of donor blood screening to the State Serum Institute on a monthly basis. This study concerns the data reported in the above two period. Reports from the years given above are worked out in the present study.

RESULTS

The frequencies of infection among candidate donors are for HIV: 4.8 per 100,000; hepatitis C: 52.7 per 100,000; and hepatitis B: 60 per 100. The yearly incidences of new infections among the 260,000 regular donors in Denmark are for HIV: 0.42 per 100,000 regular donors; hepatitis C: 0.64 per 100,000 regular donors; and hepatitis B: 0.70 per 100,000 regular donors. All donations in Denmark were tested for anti-HTLV-I/II in the period 1 April 1994 to 1 October 1997, after which only candidate donors were tested. The frequency of HTLV-I infection in previously untested donors was 1 in 60,000 and that of HTLV-II infection 1 in 150,000. The frequency of HTLV-I infection among candidate donors was 1 in 50,000 and that of HTLV-II infection 1 in 100,000. No seroconverters have been found.

Screening for viral markers in volunteer and replacement blood donors in West Africa

BACKGROUND AND OBJECTIVES

West Africa is a highly endemic area for viral infections. The prevalence of five viral markers was determined in Ghanaian blood donors.

MATERIALS AND METHODS

Replacement and volunteer blood donors were screened using enzyme immunoassays (EIAs) for hepatitis B surface antigen (HBsAg), human immunodeficiency virus antibodies (anti-HIV), HIV p24 antigen, human T-cell lymphocytotrophic virus-I and -II antibodies (anti-HTLV-I/II) and hepatitis C virus antibodies (anti-HCV).

RESULTS

HBsAg was present at an equally high frequency (15%) in young volunteer (median age 18 years) and older replacement (median age 33 years) blood donors. In contrast, the prevalence of anti-HIV and anti-HCV was significantly higher in replacement blood donors (2.4 and 0.3%, respectively, P < 0.001). HCV RNA was detected in 74 or 55% of seropositive donors, depending on the confirmatory criteria used. No p24 antigen-positive/anti-HIV-negative donations were found. The prevalence of HTLV-I/II was generally low (0.5%).

CONCLUSION

All blood donations should be screened for hepatitis B virus (HBV), HIV and HCV markers.

A seroepidemiological survey of HTLV-I/II carriers in the Puna Jujeña

Human T-cell leukemia virus type I (HTLV-I) carriers are clustered in limited groups in the world. One of these groups is the Andean native population of South America. As part of an international collaborative study devoted to explore the clustering of HTVL-I carriers in different countries, the aim of this paper was to evaluate the seroprevalence of HTLV-I/II virus in the native population of Puna Argentina in Jujuy. Blood samples of individuals of three populations of Puna Jujeña (Susques, Rinconada, Cochinoca) were screened with particle agglutination (PA), immunofluorescence (IF) and western immunoblotting analysis (WB) tests. Two out 86 (2.32%) individuals examined in the Puna Jujeña showed positive results for HTLV-I antibodies. It is concluded that the Province of Jujuy, in particular its less miscegenated highest altitude areas, constitute the northern and southern Andean natural geographical clustering of HTLV-I. This distribution is probably linked both to a history of prehistoric human dispersal in the Andes and to high mother- to-child transmission of the virus under close conditions of each group.

[Evaluation of commercial equipment used in blood banks in Córdoba for the detection of anti-HTLV-I/II antibodies]

In order to assess the efficiency of currently used screening tests, Abbott HTLV-I/HTLV-II EIA, Vironostika HTLV-I/II Organon Teknika, Particle Agglutination (PA) assay Serodia Fujirebio Inc. (Tokyo, Japan) for HTLV-I/II antibody detection in blood donors samples, a panel of 100 sera from different blood banks of Córdoba city were studied. An "in house" indirect immunofluorescence assay (IFA) was used as reference test. The correlation rates were: 66% for Abbott HTLV-I/HTLV-II EIA, 97% for Vironostika HTLV-I/II Organon Teknika EIA and 99% for PA Serodia. Vironostika HTLV-I/II Organon Teknika EIA and PA Serodia assay proved to be more reliable for HTlV-I/II antibody screening in blood donors from Córdoba, yielding a very low rate of false positive results as compared with Abbot HTLV-I/HTLV-II EIA.

Seroprevalence of HIV and HTLV in a representative sample of the Spanish population

HIV and HTLV seroprevalence was determined by means of unlinked anonymous testing of 2144 sera, originally obtained from primary care patients by representative sampling of the Spanish population aged 15-39 years in 1996. HIV-1 seroprevalence was 4.3 per 1000 population in the 15-39 years age group [95% confidence interval (CI), 1.5-10.7] and 5.6 per 1000 (95% CI, 1.8-15.3) in the 20-39 years age group. Seroprevalence proved higher in males and urban residents. No antibodies to HIV-2 and HTLV-I were detected in any of the sera studied. However, presence of antibodies to HTLV-II was confirmed in one serum sample, while HTLV seroreactivity, though detected in another, could not be typed. The two HTLV-positive results equated to a seroprevalence of 1.9 per 1000 in the 20-39 years age group (95% CI, 0.3-8.6). HIV-I seroprevalence was consistent with previous estimates yielded by back-calculation. The level of HTLV seroprevalence found suggests endemicity.

Absence of evidence of infection with divergent primate T-lymphotropic viruses in United States blood donors who have seroindeterminate HTLV test results

BACKGROUND

Recent identification of divergent simian or primate T-lymphotropic viruses (STLVs; PTLVs) in bonobos (formerly called pygmy chimpanzees; Pan paniscus; viruses: STLVpan-p and STLVpp1664) and a baboon (Papio hamadryas; viruses: STLVph969 or PTLV-L) have raised the possibility of human infection with these viruses. Divergent PTLV-infected primate sera show p24 bands on HTLV-I Western blots (WBs). It was investigated whether infection by divergent PTLV-like viruses could explain a subset of United States blood donors who reacted on HTLV-I EIAs and had indeterminate HTLV-I WBs with p24 bands.

STUDY DESIGN AND METHODS

Epidemiologic characteristics of 1889 donors with HTLV-I-indeterminate WBs were compared to those of donors with confirmed retrovirus infections (393 with HIV, 201 with HTLV-I, 513 with HTLV-II) and 1.6 million donors with nonreactive screening tests. To directly probe for infection with divergent PTLVs, 2 HTLV-I-indeterminate donors born in Africa and 269 representative non-African-born donors with p24 bands on HTLV-I WBs (previously shown to be negative for HTLV-I and -II DNA by PCR) were selected for PTLV PCR analysis. DNA from peripheral blood MNC samples was tested for a proviral tax sequence by PCR using generic primers that amplify HTLV-I, HTLV-II, and the divergent PTLVs. Amplified tax sequences were detected by Southern blot hybridization to a (32)P-labeled generic PTLV probe. PCR-positive samples could then be typed by hybridization with virus-specific internal probes that differentiate HTLV-I, HTLV-II, PTLV-L, and STLVpan-p.

RESULTS

In the epidemiologic analysis, HTLV-indeterminate status was independently associated with age of at least 25 years (OR = 2.19; 95% CI, 1.93-2.49), black (OR = 3.27; 95% CI, 2.90-3.67) or Hispanic (OR = 1.82; 95% CI, 1.52-2.16) race or ethnicity, and donation at one blood center (Baltimore) (OR = 1. 30; 95% CI, 1.11-1.53). None of the 271 HTLV-I WB-indeterminate samples tested positive by generic PTLV PCR analysis.

CONCLUSION

Although the epidemiologic data suggest the possibility of undiagnosed HTLV-I, HTLV-II, or a cross-reactive virus such as PTLV among older, black, and Hispanic blood donors, the PCR data do not support the presence of divergent PTLV infection among US blood donors with HTLV-I-indeterminate results.

Evidence among blood donors for a 30-year-old epidemic of human T lymphotropic virus type II infection in the United States

The demographic and geographic determinants of human T lymphotropic virus types I and II (HTLV-I and -II) are not well defined in the United States. Antibodies to HTLV-I and -II were measured in 1.7 million donors at five US blood centers during 1991-1995. Among those tested, 156 (9.1/10(5)) were HTLV-I seropositive and 384 (22.3/10(5)) were HTLV-II seropositive. In contrast to monotonously increasing age-specific HTLV-I seroprevalence, HTLV-II prevalence rose until age 40-49 years and declined thereafter, suggesting a birth cohort effect. HTLV-II infection was independently associated with an age of 40-49 years (odds ratio [OR], 12.4; 95% confidence interval [CI], 8.8-18.9), female sex (OR, 3.3; 95% CI, 2.6-4.1), high school or lower education (OR, 1.7; 95% CI, 1.3-2.1), hepatitis C seropositivity (OR, 25.0; 95% CI, 17.5-35.8), and first-time blood donation (OR, 3.6; 95% CI, 2.8-4.7). HTLV-II seroprevalence was highest at the two West Coast blood centers. These data are consistent with a 30-year-old epidemic of HTLV-II in the United States due to injection drug use and secondary sexual transmission and with an apparent West Coast focus.

First seroepidemiological study and phylogenetic characterization of human T-cell lymphotropic virus type I and II infection among Amerindians in French Guiana

We investigated the serological, epidemiological and molecular aspects of human T-cell lymphotropic virus type I and II (HTLV-I/II) infection in the Amerindian populations of French Guiana by testing 847 sera. No HTLV-II antibodies were detected, but five individuals (0.59%) were seropositive for HTLV-I. Analysis of the nucleotide sequences of 522 bp of the env gene and the compete LTR showed that all of the strains from French Guiana belonged to the cosmopolitan subtype A. The similarities were greater between Amerindian and Creole strains than between Amerindian and Noir-Marron strains or than between Creole and Noir-Marron strains. Phylogenetic analysis showed two clusters: one of strains from Amerindians and Creoles, which belong to the transcontinental subgroup, and the other of strains from Noirs-Marrons, belonging to the West African subgroup. Our results suggest that the Amerindian HTLV-I strains are of African origin.

HTLV-I/II seroindeterminate Western blot reactivity in a cohort of patients with neurological disease

The human T-cell lymphotropic virus type I (HTLV-I) is associated with a chronic, progressive neurological disease known as HTLV-I-associated myelopathy/tropical spastic paraparesis. Screening for HTLV-I involves the detection of virus-specific serum antibodies by EIA and confirmation by Western blot. HTLV-I/II seroindeterminate Western blot patterns have been described worldwide. However, the significance of this blot pattern is unclear. We identified 8 patients with neurological disease and an HTLV-I/II seroindeterminate Western blot pattern, none of whom demonstrated increased spontaneous proliferation and HTLV-I-specific cytotoxic T lymphocyte activity. However, HTLV-I tax sequence was amplified from the peripheral blood lymphocytes of 4 of them. These data suggest that patients with chronic progressive neurological disease and HTLV-I/II Western blot seroindeterminate reactivity may harbor either defective HTLV-I, novel retrovirus with partial homology to HTLV-I, or HTLV-I in low copy number.

High rate of human T lymphotropic virus type IIa infection in HIV type 1-infected intravenous drug abusers in Ireland

Serological and molecular analyses of a cohort of HIV-1-infected intravenous drug abusers (IVDAs) (n = 103) in Dublin, Ireland have demonstrated that 15 of 103 (14.6%) were infected with HTLV-II, which is the highest infection rate yet recorded for any European country. Restriction fragment length polymorphism (RFLP) analysis of the env region of the provirus demonstrated that the infection involved only the HTLV-IIa subtype; the HTLV-IIb subtype was not detected. Phylogenetic analysis of the nucleotide sequences of the long terminal repeat (LTR) confirmed infection with the HTLV-IIa subtype, and demonstrated that the viruses clustered closely with HTLV-IIa isolates from North American IVDAs. Previous observations that IVDAs in southern Europe, specifically Spain and Italy, appear to be infected predominantly with the HTLV-IIb subtype, along with the present report and evidence that IVDAs in Sweden are infected with the HTLV-IIa subtype, suggest different origins of HTLV-II infection in Europe.

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 Puneños 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.

Seroprevalence of HTLV-I and HTLV-II among a cohort of HIV-infected women and women at risk for HIV infection. Women's Interagency HIV Study

OBJECTIVES

To determine the seroprevalence of, and risk factors for, HTLV-I and HTLV-II infection among HIV-infected women and women at high risk for HIV infection.

DESIGN

Cross-sectional analysis of baseline data for women enrolled in the prospective Women's Interagency HIV Study (WIHS).

METHODS

From October 1994 through November 1995, 2657 women from five metropolitan areas in the United States (Chicago, Los Angeles, New York City [two sites], Northern California, and Washington DC) were enrolled in WIHS. An interview-based survey collected data on demographics, behavior, and medical history. HTLV-I and HTLV-II determinations were made using a combined HTLV-I/HTLV-II indirect immunofluorescent antibody (IFA) screening test, an IFA titration specificity test, and individual HTLV-I and HTLV-II confirmatory Western blots. Fisher's exact tests and logistic regression were used to determine univariate and multivariate independent predictors for HTLV-II infection.

RESULTS

Of 2625 women enrolled in WIHS with confirmed HIV results, 2487 (95%) were tested for HTLV-I and HTLV-II. Of these, 241 (10%) were HTLV-II-seropositive and 13 (0.5%) were HTLV-I-seropositive. On multivariate analysis, independent predictors of HTLV-II infection included injection drug use (OR = 5.2; p < .001), black race (OR = 3.6; p < 0.001), age >35 years (OR = 3.3; p < .001) and a history of sex with a male injecting drug user (OR = 1.9; p < .001). Among women infected with HIV, the seroprevalence of HTLV-II was 11% compared with 6% for women at risk for HIV but not infected (p < .001). However, HIV was not an independent predictor of HTLV-II infection in multivariate analysis.

CONCLUSIONS

This cross-sectional analysis confirms that HTLV-II is found commonly in HIV-infected women and uninfected women at risk for HIV in major urban areas throughout the United States and that HTLV-II is far more common than HTLV-I in these populations. Although injecting drug use is most strongly associated with HTLV-II infection, sexual transmission likely contributes to the high HTLV-II seroprevalence in this cohort.