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Advances in laboratory and information technologies are transforming public health microbiology. High-throughput genome sequencing and bioinformatics are enhancing our ability to investigate and control outbreaks, detect emerging infectious diseases, develop vaccines, and combat antimicrobial resistance, all with increased accuracy, timeliness, and efficiency. The Advanced Molecular Detection (AMD) initiative has allowed the Centers for Disease Control and Prevention (CDC) to provide leadership and coordination in integrating new technologies into routine practice throughout the U.S. public health laboratory system. Collaboration and partnerships are the key to navigating this transition and to leveraging the next generation of methods and tools most effectively for public health., (Copyright © 2017 American Society for Microbiology.)

In the USA, infectious diseases continue to exact a substantial toll on health and health-care resources. Endemic diseases such as chronic hepatitis, HIV, and other sexually transmitted infections affect millions of individuals and widen health disparities. Additional concerns include health-care-associated and foodborne infections--both of which have been targets of broad prevention efforts, with success in some areas, yet major challenges remain. Although substantial progress in reduction of the burden of vaccine-preventable diseases has been made, continued cases and outbreaks of these diseases persist, driven by various contributing factors. Worldwide, emerging and reemerging infections continue to challenge prevention and control strategies while the growing problem of antimicrobial resistance needs urgent action. An important priority for control of infectious disease is to ensure that scientific and technological advances in molecular diagnostics and bioinformatics are well integrated into public health. Broad and diverse partnerships across governments, health care, academia, and industry, and with the public, are essential to effectively reduce the burden of infectious diseases., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

In 1983, reports of antibodies in subjects with major depressive disorder (MDD) to an as-yet uncharacterized infectious agent associated with meningoencephalitis in horses and sheep led to molecular cloning of the genome of a novel, negative-stranded neurotropic virus, Borna disease virus (BDV). This advance has enabled the development of new diagnostic assays, including in situ hybridization, PCR and serology based on recombinant proteins. Since these assays were first implemented in 1990, more than 80 studies have reported an association between BDV and a wide range of human illnesses that include MDD, bipolar disorder (BD), schizophrenia (SZ), anxiety disorder, chronic fatigue syndrome, multiple sclerosis, amyotrophic lateral sclerosis, dementia and glioblastoma multiforme. However, to date there has been no blinded case-control study of the epidemiology of BDV infection. Here, in a United States-based, multi-center, yoked case-control study with standardized methods for clinical assessment and blinded serological and molecular analysis, we report the absence of association of psychiatric illness with antibodies to BDV or with BDV nucleic acids in serially collected serum and white blood cell samples from 396 subjects, a study population comprised of 198 matched pairs of patients and healthy controls (52 SZ/control pairs, 66 BD/control pairs and 80 MDD/control pairs). Our results argue strongly against a role for BDV in the pathogenesis of these psychiatric disorders.

In response to the emergence of severe acute respiratory syndrome (SARS), the United States established national surveillance using a sensitive case definition incorporating clinical, epidemiologic, and laboratory criteria. Of 1,460 unexplained respiratory illnesses reported by state and local health departments to the Centers for Disease Control and Prevention from March 17 to July 30, 2003, a total of 398 (27%) met clinical and epidemiologic SARS case criteria. Of these, 72 (18%) were probable cases with radiographic evidence of pneumonia. Eight (2%) were laboratory-confirmed SARS-coronavirus (SARS-CoV) infections, 206 (52%) were SARS-CoV negative, and 184 (46%) had undetermined SARS-CoV status because of missing convalescent-phase serum specimens. Thirty-one percent (124/398) of case-patients were hospitalized; none died. Travel was the most common epidemiologic link (329/398, 83%), and mainland China was the affected area most commonly visited. One case of possible household transmission was reported, and no laboratory-confirmed infections occurred among healthcare workers. Successes and limitations of this emergency surveillance can guide preparations for future outbreaks of SARS or respiratory diseases of unknown etiology.

Improvements in donor selection, testing of donors for markers of infection, and viral inactivation of plasma-derived products have helped reduce the risk of transfusion-associated infections, including hepatitis B (HBV), hepatitis C (HCV), and human immunodeficiency viruses (HIV). The potential for transmission of emerging infections is illustrated by current concerns about group O strains of HIV, nonenveloped viruses, newly discovered microbial agents, prions, Chagas' disease, tick-borne infections, and the need to assess the frequency of transfusion reactions associated with bacterial contamination.

Five hundred fifty persons who worked with nonhuman primates (NHP) or with NHP material in 13 North American research institutions were surveyed for potential occupational exposures and tested for antibodies to simian immunodeficiency virus (SIV). Needlesticks and mucocutaneous exposures were reported more frequently among persons who handled SIV-negative or SIV-status-unknown (SIV-N/U) animals (36% and 35%) or who worked with SIV-N/U material in the laboratory (18% and 17%) than among persons who handled SIV-positive NHP (SIV-P) (9% and 4%) or worked with SIV-P material (6% and 8%). The risk for needlesticks when working with both SIV-N/U and SIV-P animals and the risk for mucocutaneous exposures from SIV-N/U animals increased with the number of years working with NHP. Persons who performed invasive tasks (e.g., obtaining blood samples, performing surgery/autopsies) were more likely than others to sustain needlesticks (adjusted OR = 3.55, 95%CI = 1.40-9.02). Two (0.4%) of 550 persons had antibodies to SIV. One appears to be infected with SIV, as previously reported. These data suggest that persons who work with NHP or with NHP material are at risk for occupational exposure to potentially infectious materials including SIV. Prevention strategies are needed to reduce the risk for needlesticks and mucocutaneous exposures around all NHP, and safety guidelines should emphasize prevention options for invasive tasks performed with animals.

Differentiating occupational exposure from other potential domestic or recreational exposure(s) for Sin Nombre virus (SNV) infection is an epidemiologic challenge. Interviews on work-related activities were conducted, and serum specimens were obtained from 494 workers in Arizona and New Mexico. These workers may have been exposed to rodents and rodent excreta at work, but their primary occupation did not require rodent contact (National Park Service [n = 193]; Navajo Agricultural Product Industry [n = 65], utility companies [n = 169] and plumbing and heating contractors [n = 67]. Within each occupational group (farm workers [n = 57], laborers [n = 20], professionals [n = 70], repairers [n = 211], service industry workers [n = 83], and technicians [n = 53], the majority of workers reported working in areas that had rodent droppings (range, 75 to 95%); 70% of laborers and 64% of service industry workers reported handling rodents. More than 60% of workers in each group, except technicians, reported reopening and cleaning or working in closed spaces. Approximately 90% of laborers, repairers, and farm workers reported hand-plowing. Although the risk for occupationally related SNV infection appears to be low, workers frequently performed risk activities associated with hantavirus pulmonary syndrome (HPS). All workers were seronegative for SNV by enzyme-linked immunoassay or Western blot testing. These findings, the known occupational exposure of some HPS cases, and the high HPS case-fatality rate (52%) support the need for recommendations to reduce human contact with rodents in the workplace. Increased understanding of hantavirus transmission to humans will help focus future recommendations to minimize human exposures effectively.

Summary: Risk factors for male-to-female sexual transmission of human T-lymphotropic virus types I and II (HTLV-I/II) were investigated among HTLV-seropositive volunteer blood donors and their long-term (> or = 6 month) sex partners. Direction of transmission in concordantly seropositive pairs was assessed by analyzing risk factors for HTLV infection. Donors and their partners were also questioned regarding sexual behaviors during their relationships; HTLV antibody titers and viral load were determined for specimens from male partners. Among 31 couples in whom HTLV-infected men likely transmitted infection to their partners (11 HTLV-I and 20 HTLV-II) and 25 male-positive, female-negative couples (8 HTLV-I and 17 HTLV-II), HTLV transmitter men had been in their relationships longer (mean 225 months vs. 122 months) and had higher viral loads (geometric mean 257,549 vs. 2,945 copies/300,000 cells for HTLV-I; 5,541 vs. 118 copies/300,000 cells for HTLV-II) than non-transmitters (P = 0.018 and P = 0.001 for duration of relationship and viral load, respectively, logistic regression analysis). Transmitter men also tended to have higher antibody titers against various env and whole virus proteins than non-transmitters. The identification of high viral load and duration of relationship as risk factors provides a biologically plausible framework in which to assess risk of sexual transmission of the HTLVs.

In the spring of 1993, hantavirus pulmonary syndrome (HPS) "emerged" in the southwestern United States, where a multiagency investigation led to the rapid description of this new clinical entity and its etiology. Analysis of the first 100 US cases identified showed that the disease was distributed in 21 states, had gone unrecognized since at least 1959, and had a distinct spring-early summer seasonality. Of the infected persons, 54% were male; 63% were Caucasian, 35% were Native American, and 2% were African American. The average age of case-patients was 34.9 years, and 8 were children or adolescents aged < or = 16 years. The overall case-fatality rate was 52%. There was a 91% concordance among serologic, immunohistochemical, and molecular results. HPS in the United States is caused by at least three newly described pathogenic hantaviruses, each of which has a distinct rodent host, and cases of HPS have been recently recognized in Canada and South America. National surveillance of this sporadic disease remains essential for further defining the epidemiology and clinical spectrum.

Objective: Retroviruses can cause immunoregulatory disturbances and may play a role in the pathogenesis of autoimmune disorders. Little is known about the frequency of behavioral risk factors for exogenous retroviral infections in patients with autoimmune diseases. We compare the frequency of recognized risk factors for retroviral infections among patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and controls., Methods: Patients with SLE and RA from a university rheumatology clinic and control patients were enrolled in this study. The presence of retroviral risk factors (intravenous drug use, prostitution, increased number of sex partners, sexually transmitted diseases, high risk sex partners, blood transfusion) was determined by a self-administered questionnaire., Results: We surveyed 81 patients with SLE and 117 with RA and 100 healthy controls. Patients in all groups reported similar exposure to all risk factors surveyed for retroviral infection except sexually transmitted disease, which was reported more often in patients with SLE (25% of SLE versus 11% of RA and 11% of controls, p = 0.013)., Conclusion: Self-reported retroviral risk factors were generally not increased in patients with autoimmune disease compared to healthy controls; the role of exogenous retroviruses in the pathogenesis of SLE and RA remains unclear.

On May 27, 1993, in response to the outbreak investigation of newly recognized Hantavirus pulmonary syndrome (HPS) in the Four Corners states (New Mexico, Arizona, Utah, and Colorado), the Centers for Disease Control and Prevention established a national surveillance case definition for severe, unexplained respiratory disease to determine the extent of HPS throughout the United States. A toll-free telephone hotline number was instituted to provide updated information about unexplained respiratory illness and to serve as a passive mechanism for reporting suspected cases. Clinical information was obtained from callers reporting suspected cases, and diagnostic specimens and medical record reviews were requested from health care providers. From June 3 through December 31, 1993, the hotline received 21,443 telephone inquiries; callers identified 280 suspected cases living outside the Four Corners states with at least one specimen available for diagnostic testing. By December 31, 1993, 21 confirmed cases (age range, 14 to 58 years) residing in 11 states outside the Four Corners region had been identified. This passive surveillance system was successful in rapidly identifying the widespread sporadic geographic distribution for HPS cases throughout the United States and could serve as a model for similar emergencies. Expanding and coordinating surveillance systems for the early detection, tracking, and evaluation of emerging infections is a critical component of disease prevention.

Objective: To investigate the occurrence of unrecognized cases of hantavirus pulmonary syndrome preceding the detection of the 1993 outbreak in the southwestern United States and the initial description of the syndrome., Design: Retrospective clinicopathologic and immunohistologic study., Patients: Eighty-two patients who died prior to April 1993 with histologically unexplained noncardiogenic pulmonary edema., Methods: Clinicopathologic review and immunohistochemical evaluation of autopsy tissues for evidence of hantaviral infection., Results: Twelve retrospective fatal cases of hantavirus pulmonary syndrome were identified through clinicopathologic review and immunohistochemical testing of tissues. Patients' ages ranged from 16 to 49 years. The earliest identified case occurred in 1978, 15 years prior to the outbreak of hantavirus pulmonary syndrome in the southwestern United States. Immunohistochemical testing showed widespread deposition of hantaviral antigens, primarily within endothelial cells, similar to the pattern observed with current hantavirus pulmonary syndrome cases., Conclusions: Although hantavirus pulmonary syndrome was first recognized in 1993, the findings from this study document the earlier existence of this disease. These findings underscore the need for systematic archiving and analysis of clinical information and specimens from patients with diseases of unknown etiology to facilitate the study of new clinical entities and their associated etiologic agents.

Hantavirus pulmonary syndrome (HPS) is a recently recognized viral zoonosis. The first recognized cases were caused by a newly described hantavirus. Sin Nombre virus (previously known as Muerto Canyon virus), isolated from Peromyscus maniculatus (deer mouse). We describe a 33-year-old Floridian man who resided outside the ecologic range of P maniculatus but was found to have serologic evidence of a hantavirus infection during evaluation of azotemia associated with adult respiratory distress syndrome. Small mammal trapping conducted around this patient's residence demonstrated the presence of antihantaviral antibodies in 13% of Sigmodon hispidus [cotton rat). Serologic testing using antigen derived from the Black Creek Canal hantavirus subsequently isolated from this rodent established that this patient was acutely infected with this new pathogenic American hantavirus. HPS is not confined to the geographical distribution of P maniculatus and should be suspected in individuals with febrile respiratory syndromes, perhaps associated with azotemia, throughout the continental United States.

Molecular subtyping of human T-cell lymphotropic virus type 2 (HTLV-2) by the currently used method of restriction fragment length polymorphism analysis may not be sufficiently discriminatory for transmission studies because of the predominance of single restriction types in various HTLV-2-infected populations. The utility of single-strand conformations polymorphism (SSCP) analysis was evaluated as a tool to improve the sensitivity of the subtyping of HTLV-2. The assay was designed to target a highly variable region in the long terminal repeat and was shown to be able to detect single nucleotide changes in cloned HTLV-2 sequences. Analysis of 52 HTLV-2 samples, of which 32 were from 16 sex partner pairs (16 males, 16 females), showed nine different SSCP patterns. Identical SSCP results were obtained for each of the 16 couples, suggesting the presence of similar viral genotypes and, therefore, supporting the likelihood of sexual transmission of HTLV-2 in each of these couples. Furthermore, SSCP analysis of seven HTLV-2 samples of the same restriction type (b5) showed five different SSCP patterns. Nucleotide sequencing of two samples with distinct SSCP patterns confirmed the sequence differences. SSCP provides a facile and discriminatory tool for the differentiation of HTLV-2 strains, including those previously indistinguishable by restriction fragment length polymorphism.

Human T-lymphotrophic virus type II (HTLV-II) has not yet been associated with any disease. Little is known about the proviral loads of HTLV-II in vivo and its relationship, if any, to lack of pathogenicity. We determined the HTLV-II proviral copy number in peripheral blood lymphocyte (PBL) samples from 49 HTLV-II-infected individuals, of whom 25 were coinfected with human immunodeficiency virus type 1 (HIV-1). The HTLV-II copy numbers were determined by polymerase chain reaction (PCR) amplification of end-point dilutions of PBL lysates, followed by hybridization to a 32P-labeled HTLV-II-specific probe. The proviral copy number for the 49 samples ranged from < 0.02 to 200 per 1000 PBLs; 6% had < 0.02, 16% had 0.02, 20% had 0.2, 18% had 2, 31% had 20, and 8% had 200 copies per 1000 PBLs. The distributions of HTLV-II copy numbers in the coinfected and singly infected subgroups were not significantly different (Wilcoxon rank sum, p = 0.24). In the coinfected subgroup, there was no significant correlation between the HTLV-II proviral load and the counts of CD4-positive lymphocytes or CD8-positive lymphocytes (Spearman Coefficient = 0.26, p = 0.20; = 0.091, p = 0.67, respectively). Our data demonstrate the presence of a wide range of viral loads in HTLV-II-infected individuals. The high viral loads (> or = 20 copies/1000 lymphocytes) detected in 39% of our samples suggest that the low pathogenicity of HTLV-II is not related to the presence of low viral loads in the infected subjects. Our data from the HIV-1 coinfected individuals show no apparent effect of HIV-1 on HTLV-II proviral loads.

To determine the incidence of and risk factors for human T-lymphotropic virus, type II (HTLV-II) seroconversion among injecting drug users (IDUs), specimens from IDUs recruited into the ALIVE Study in 1988/1989 were assayed at baseline for antibody to HTLV with use of enzyme immunoassay and Western blot. Participants were monitored semiannually with venipuncture and interviews. In 1992, the most recent sera of HTLV-negative participants were tested for HTLV with use of enzyme immunoassay and confirmed and typed by Western blot. For positive cases, assays were then performed for all intervening visits to determine the calendar time of seroconversion. Incidence rates were estimated using person-time. Risk factor analysis used a nested case-control design, with up to seven controls per case matched by time of study entry and duration of follow-up. At baseline, 251 HTLV-positive, 22 indeterminate, and 2,574 HTLV-seronegative IDUs were identified. Follow-up of the seronegative IDUs identified 38 seroconverters (all HTLV-II) over 5,813.6 person-years, for a rate of 0.7/100 person-years. Median lag time for seroconversion was 6.8 months. Factors associated with HTLV-II seroconversion included a specific needle-sharing practice called "backloading" within the previous 6 months [odds ratio (OR) = 6.52; 95% confidence interval (CI) = 1.94-21.95] and a baseline history of receiving money for sex (OR = 3.36; 95% CI = 1.32-8.57). Of those with more than one sex partner in the past 6 months, women were more likely than men to seroconvert (OR = 5.77; 95% CI = 1.33-25.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Guaymi Indians, a non-intravenous drug-using population in which human T cell lymphotropic virus type II (HTLV-II) is endemic, were studied in Changuinola, Panama, to identify the prevalence and modes of transmission of HTLV-II. A population-based survey showed that 352 (9.5%) of the 3686 participants were seropositive for HTLV-II. Infection rates were the same for male and female subjects and increased significantly with age, beginning in young adulthood. HTLV-II infection status was highly concordant among spouses (P < .001) and between mother and child; of children aged 1-10 years, 36 of 219 born to seropositive mothers were seropositive compared with 3 of 997 born to seronegative mothers (P < .001). The strong associations of HTLV-II infection with age and with an infected spouse in adults and of infection in children with infection in their mothers strongly suggest sexual and mother-to-child transmission of HTLV-II in this population.

The current env-based subtyping of human T-cell lymphotropic virus type II (HTLV-II) identifies only two heterogenetic groups, HTLV-IIa and HTLV-IIb. To better understand the genetic diversity and phylogeny of HTLV-II, we examined the most divergent genomic region of HTLV-II, the long terminal repeat, by using restriction fragment length polymorphism (RFLP) and sequence analysis. Long terminal repeat sequences were amplified from peripheral blood mononuclear cells by PCR and digested with seven restriction endonucleases that differentiated HTLV-II into five HTLV-IIa (IIa0 to IIa4) and six HTLV-IIb (IIb0 to IIb5) restriction types, with HTLV-IIa0 and HTLV-IIb0 being prototypes for the MoT and NRA isolates, respectively. We examined 169 HTLV-II-infected samples, including 123 from blood donors and intravenous drug users (IDU) from the Americas, 16 from IDU from Europe, and 30 from Amerindians. Of the 169 samples, 109 (64.5%) were categorized as HTLV-IIa and 60 (35.5%) were categorized as HTLV-IIb. The predominant restriction types seen among the U.S. blood donors and U.S. IDU were IIa0 (68.7%) and IIb4 (10.4%). Four Spanish and seven Italian samples were IIb4, while five Norwegian samples were IIa2. Twelve Guaymi and all ten Seminole samples were single restriction types (IIb1 and IIb5, respectively), whereas the two Navajo and six Pueblo samples had a mixture of restriction types IIa0, IIa4, and IIb5. Of the HTLV-IIb restriction types observed in the U.S. non-Indians, 42.8% appear to have originated from the North Amerindian (IIb5), while 57.2% were similar to the European IIb4 restriction type. Sequences of 15 selected HTLV-II samples were determined and phylogenetically compared with 7 previously published HTLV-II LTR sequences. The derived topologies revealed three HTLV-IIa phylogroups (A-I to A-III) and four HTLV-IIb phylogroups (B-I to B-IV). Furthermore, the HTLV-IIa phylogroups appear to have evolved from the HTLV-IIb phylogroups. In the HTLV-IIa cluster, a Navajo (A-I) and a Brazilian (A-II) sequence formed separate phylogroups, while the remaining IIa sequences formed a single phylogroup (A-III). The four HTLV-IIb phylogroups were represented predominantly by a New York IDU (B-I), European IDU (B-II), North Amerindian and NRA (B-III), and Central Guaymi Indian (B-IV) sequence(s). Comparison of the phylogenetic data with the RFLP results revealed that results of the two methods correlated completely, demonstrating the ability of the RFLP method to predict the phylogroup of HTLV-II-infected samples accurately and quickly. GENBANK/U10258

In May and June 1993, a handful of previously healthy residents of rural areas in the Four Corners region of the southwestern United States died of acute unexplained respiratory distress, later diagnosed as hantavirus pulmonary syndrome. Their illnesses were characterized most prominently by a prodrome of fever and myalgias, followed by thrombocytopenia, the presence of immature white blood cells on the peripheral smear, and catastrophic respiratory decline associated with the sudden onset of noncardiogenic pulmonary edema and hypotensive shock. Although the primary care doctors who treated these patients were spread over a relatively wide rural geographic area, this cluster was recognized in large part because these patients belonged to a defined cohort receiving medical care from a unified system of interconsulting physicians, the Indian Health Service. By just over 2 weeks after receiving laboratory diagnostic specimens, Public Health Service scientists had identified a newly recognized hantavirus as the cause of this disease cluster and Peromyscus maniculatus (the deer mouse) as the rodent reservoir for this zoonotic virus. The oral history of local American Indian healers describes clusters of similar deaths occurring over three cycles during the twentieth century in association with identifiable ecological markers. The abrupt introduction to Western medical practitioners of a disease long recognized by indigenous healers through illness occurring among a cohort of patients seeking care from medical officers of the U.S. Uniformed Services parallels the initial Western medical recognition of previous human illnesses associated with hantaviral infections through disease outbreaks among military troops. The remarkable speed with which the etiology of this disease was elucidated is attributable to both the power of modern genetic investigational techniques and the scientific groundwork laid by nearly half a century of systematic research on hantaviruses.

Blood donors have been screened for antibodies to human T cell lymphotropic virus (HTLV) type I since December 1988. Screening for HTLV-II has been simultaneously done because of cross-reactivity between antibodies to the two viruses. Currently, < 1 in 10,000 US blood donors is positive for HTLV-I or -II. Lookback studies led to the identification of 6 HTLV-II-infected patients. Three received transfusions before introduction of HTLV-I screening tests, while the other 3 received blood components that tested negative for HTLV-I. The HTLV-II subtypes of each of 4 donor/recipient pairs, as determined by DNA amplification using polymerase chain reaction, were identical, supporting the view that transfusions were the source of infection. In conclusion, currently licensed blood donor screening tests for HTLV-I lack sensitivity for HTLV-II, and transfusion of blood from HTLV-II-infected donors that test negative on HTLV-I screening tests may result in infection.

We investigated the seroprevalence of human T cell lymphotropic virus type II (HTLV-II) using a screening enzyme-linked immunosorbent assay (ELISA) and immunoblot confirmation among the predominant tribes (Pueblo and Athapaskan) served by two large Indian Health Service facilities in New Mexico. Among persons being treated for sexually transmitted diseases, eight (3.2%) of 250 were seropositive for HTLV II, compared with eight (2.1%) of 385 women attending prenatal clinics. In a survey of unselected patients at one of the facilities, 15 (3.4%) of 446 were seropositive. Of 31 seropositive subjects, 25 were infected with HTLV-II and six infections could not be typed. Sera from nine (29%) of the 31 infected subjects had absorbance values less than the manufacturer's cutoff in the ELISA. Both Pueblo and Athapaskan groups had similar overall seroprevalences, but women tended to have a slightly higher seroprevalence than men, and seroprevalence tended to increase with age. These data show that HTLV-II infection is present among diverse groups of American Indians in the southwestern United States. Present ELISA screening tests, such as those used in this study, lack sensitivity to HTLV-II infection unless a reduced absorbance cutoff is used.

We investigated the prevalence of human T-cell lymphotropic virus (HTLV) types I and II among drug users entering treatment in King County, Washington, between 1988 and 1990. Of 762 injection-drug users, 81 (10.6%) were HTLV-positive; of 89 noninjection-drug users, 2 (2%) were HTLV-positive. Most (95.8%) of those typed) were HTLV-II-positive. The relationship between HTLV and demographic and behavioral characteristics was further evaluated among injection-drug users. The prevalence rates for HTLV increased 25-fold from the youngest age group (15 to 24 years) to the oldest (older than 45 years), after adjusting for race. After adjustment for age, American Indians or Alaska Natives were 7.9 times, blacks 6.2 times, Asians or Pacific Islanders 4.7 times, and Hispanics 4.1 times as likely as whites to be HTLV-positive. The prevalence of HTLV among heroin injectors was more than double that observed among injectors of other drugs after adjusting for age, although this association was only marginally significant. The strong association between HTLV prevalence and age suggests that HTLV-II (the predominant virus) has been endemic among King County injection-drug users for some time. Its relatively high prevalence indicates that there is both an opportunity and a need to further investigate the epidemiologic and clinical implications of HTLV-II infection.

Current algorithms for the serologic confirmation of human T-cell lymphotropic virus type I and II (HTLV-I/II) antibody reactivity are complicated. We evaluated the performance of an HTLV-I Western blot (immunoblot) spiked with recombinant p21e protein (p21e WB) as an alternative to current confirmatory methods. These methods include the HTLV-I viral lysate Western blot and either a radioimmunoprecipitation assay or a p21e enzyme-linked immunosorbent assay. Five hundred fifty nine blood donations obtained from five U.S. blood centers and classified as HTLV-I/II seropositive (n = 149) or seroindeterminate (n = 410) by routine testing methods were further evaluated by PCR for proviral DNA and by the p21e WB. On the basis of serologic and PCR testing, 155 donations were classified as HTLV-I/II infected. The sensitivity of the p21e WB was 97.4%, slightly exceeding that of routine confirmatory testing. The specificity of the p21e WB was 97.5%, as determined by testing of 404 seroindeterminate samples that were negative in the PCR. The positive predictive value of the p21e WB was 94%. In contrast, the specificity and positive predictive value of routine confirmatory testing were both 100%. Follow-up sampling of presumptive p21e WB false-positive donors substantiated the absence of HTLV-I/II infection. Although the p21e WB used in this study has high sensitivity and may be useful as a confirmatory assay in epidemiologic research studies, it may not be ideal as a confirmatory test for the notification of blood donors.

Evidence has recently been presented for an infection with a simian type D retrovirus in a patient with AIDS and lymphoma. We tested for simian type D infection in three groups of subjects: 375 patients with lymphoproliferative diseases (255 non-Hodgkin's, 88 Hodgkin's, and 32 chronic lymphoproliferative disease), of whom 75 were human immunodeficiency virus (HIV)-1 infected; seven persons with unexplained low CD4 lymphocyte counts with clinical conditions; and 45 blood donors, of whom 37 were human T-lymphocyte virus (HTLV)-I/II seroindeterminate and eight were HTLV-I/II and HIV-1 seronegative. Serum samples were screened for antibodies against simian type D retroviruses by an enzyme immunoassay, and reactive samples were analyzed by Western blotting. None of the samples were seropositive, but eight (five from non-Hodgkin's and three from Hodgkin's lymphoma patients) were seroindeterminate. Polymerase chain reaction analysis of genomic DNA from peripheral blood lymphocytes of all eight of these patients was carried out using simian type D gag generic primers with generic internal oligoprobing. All samples were negative. We conclude that simian type D infection is rare among HIV-infected and noninfected lymphoma patients, persons with unexplained low CD4 counts, and persons with HTLV-seroindeterminate test results.

Two recombinant fusion proteins representing the C-terminus of the envelope glycoprotein of HTLV-I (rEnv-93(201-440)) and the C-terminus of the external glycoprotein (RE-3(165-306)) were tested in a Western blot (WB) assay for their ability to detect the presence of env antibodies in serum specimens from HTLV-I (n = 27) and HTLV-II (n = 22) infected individuals. The rEnv-93 reacted with 27 (100%) of 27 HTLV-I-infected specimens and 19 (86%) of 22 of HTLV-II-infected specimens. In contrast, RE-3 reacted with 25 (93%) of 27 HTLV-I-infected specimens, and only six (27%) of 22 HTLV-II-infected specimens, thus demonstrating predominant reactivity with HTLV-I compared with HTLV-II. Because of the high sensitivity of rEnv-93 reactivity in both HTLV-I and HTLV-II, the specificity of this env protein was evaluated in specimens with isolated gag reactivity (HTLVind). Of the 44 HTLVind specimens, four (9%) demonstrated reactivity to rEnv-93 in WB assay. We, therefore, conclude that although rEnv-93 is highly sensitive for detection of env protein, it has the potential to yield some false-positive reactions presumably due to the conserved nature of retroviral transmembrane epitopes.

We have investigated the isotypic and IgG subclass profile of the antibody response to HTLV-I structural proteins (gag and env) in patients with HTLV-I-associated myelopathy (HAM; n = 20), adult T-cell leukemia (ATL; n = 15), and HTLV-I-positive asymptomatic carriers (ASY; n = 21). IgG, IgM, and IgA were the predominant antibody responses in all HTLV-I-infected individuals; minimal IgE response was detectable in the HAM and ATL groups. Among the IgG subclasses, IgG1 was the most predominant antibody detected in responses to HTLV-I antigens, followed by IgG3 and IgG2; IgG4 could not be detected in any patient group. Levels of both IgG1 and IgG3 were significantly higher in patients with HAM, when compared to ATL and ASY (P < 0.01 for both comparisons). In addition, Ig isotypes and IgG subclass antibody in patient sera reactive with purified viral proteins and several immunodominant epitopes, represented by synthetic peptides, Gag-1a102-117, Env-1(191-214), Env-5(242-257), and recombinant proteins, MTA-1(162-209) and r21e303-440, were examined to delineate specific epitopes responsible for inducing the host immune responses of each isotype and subclass to the structural proteins of HTLV-I. IgG, IgM, and IgA responses were directed against both the gag and env gene products. Among IgG subclasses, the IgG1 and IgG3 responses were directed against both the gag (p53, p24, p19, and Gag-1a) and env (recombinant MTA-1, r21e, and synthetic Env-1, Env-5) proteins; IgG2 responses were mainly restricted to gag proteins. The frequency profile of HTLV-I-specific antigen recognition in all four IgG subclasses were similar in all of the clinical groups. These results further define the fine specificity of anti-HTLV-I immune reaction for understanding the mechanism of pathogenesis in these individuals and suggest that factors other than the humoral immune responses may be associated with the clinical manifestation of the disease.

The confirmation of infection with human T-cell lymphotropic virus type I (HTLV-I) and type II (HTLV-II) currently involves multiple assays. These include Western blot (immunoblot) (WB) and/or radioimmunoprecipitation assay for detection of antibodies to HTLV-specific viral proteins and polymerase chain reaction and/or peptide-based enzyme immunoassays for differentiating between the two viruses. We undertook an evaluation of a modified WB assay that includes native HTLV-I viral proteins from MT-2 cells spiked with an HTLV-I transmembrane glycoprotein (recombinant p21e) and the HTLV-I- and HTLV-II-specific recombinant proteins MTA-1 and K55. The test panel consisted of well-characterized sera from U.S. blood donors, American Indians, intravenous drug users, and patients seen in sexually transmitted disease clinics. Of 158 HTLV-I/II-seropositive serum specimens tested, 156 (98.7%) were confirmed and typed as HTLV-I or HTLV-II. Of 82 HTLV-I/II-seroindeterminate or -seronegative serum specimens, only 1 was classified as HTLV-II positive: the sample had weak gag p19 and strong gag p24 and env p21e reactivity and was radioimmunoprecipitation assay negative for env gp61/68 but polymerase chain reaction positive for HTLV-II. The specificity of the modified WB for confirming and typing serum samples was therefore 100%. We conclude that this WB assay is useful for confirming and typing HTLV infection and can help simplify HTLV-I/II testing algorithms.

The macaque monkey infected with simian immunodeficiency virus (SIV) is an animal model of the acquired immunodeficiency syndrome. We investigated a laboratory worker who was exposed by needlestick accident to blood from an SIV-infected macaque. Seroreactivity to SIV developed within 3 months of exposure, with antibody titres peaking from the third to the fifth month and declining thereafter. Polymerase chain reaction for SIV sequences and cultures of peripheral-blood mononuclear cells failed to show infection. Inoculation of an SIV-negative monkey with blood from the worker did not cause infection. Animal-care and laboratory workers should adhere strictly to recommended procedures to avoid accidental exposures when working with SIV-infected animals or specimens.

To confirm and differentiate between human T-cell lymphotropic virus type I (HTLV-I) and HTLV-II infections, we analyzed by polymerase chain reaction (PCR) samples of peripheral blood lymphocytes from 98 individuals seropositive for HTLV-I/II using pol (SK110/111) and tax (SK43/44) consensus primer pairs. A total of 96 samples (97.9%) were positive by the tax generic probe, while 95 were typed by the HTLV-I and HTLV-II pol probes. The three pol-negative samples were successfully amplified and typed by nested PCR with primers internal to SK110 and SK111. Results of PCR with a lysate of leukocyte nuclei obtained by whole blood lysis were comparable to those obtained with peripheral blood lymphocytes from 16 HTLV-seropositive subjects.

Unlabelled: Background. The human T-cell lymphotropic virus Type I (HTLV-I) is associated with adult T-cell leukemia and myelopathy, whereas HTLV-II infection has uncertain clinical consequences. We assessed the seroprevalence of these retroviruses among intravenous drug users and among patients seen at clinics for sexually transmitted diseases (STD clinics)., Methods: We used serum samples that were collected in eight cities in 1988 and 1989 during surveys of human immunodeficiency virus infection among intravenous drug users entering treatment and persons seen in STD clinics. The serum samples were tested for antibodies to HTLV, and positive specimens were tested further by a synthetic peptide-based enzyme-linked immunosorbent assay to differentiate between HTLV-I and HTLV-II., Results: Among 3217 intravenous drug users in 29-drug-treatment centers, the median seroprevalence rates of HTLV varied widely according to city (range, 0.4 percent in Atlanta to 17.6 percent in Los Angeles). Seroprevalence increased sharply with age, to 32 percent in persons over 44 years of age. HTLV infection was more common among blacks (15.5 percent) and Hispanics (10.7 percent) than among whites (4.1 percent), and it was strongly associated with a history of heroin injection (P less than or equal to 0.001). Among 5264 patients in 24 STD clinics, the median rates of HTLV infection were much lower (range, 0.1 percent in Atlanta and Newark to 2.0 percent in Los Angeles). Again, this infection was more common among intravenous drug users (7.6 percent) than among non-drug users (0.7 percent). Eighty-four percent of the seropositive samples from drug-treatment centers and 69 percent of those from STD clinics were due to HTLV-II infection (P = 0.03)., Conclusions: HTLV infections are common among intravenous drug users and are primarily caused by HTLV-II. Among patients seen at STD clinics, HTLV is strongly associated with intravenous drug use, but the retrovirus is also prevalent among non-drug users.

Current screening tests to detect human T-lymphotropic virus type I (HTLV-I) in volunteer blood donors commonly yield indeterminate HTLV serologic results (mostly isolated gag reactors). To assess the significance of indeterminate HTLV serologic results in U.S. blood donors, we compared 56 persons who had such serologic patterns with 30 HTLV seropositive blood donors and with HTLV seronegative controls. Polymerase chain reaction assays showed that none of the 56 individuals with indeterminate HTLV serologic results were infected with HTLV-I or HTLV-II, while all 30 HTLV seropositive blood donors were infected with either HTLV-I (in 15) or HTLV-II (in the other 15). The seroindeterminate blood donors were also different from the HTLV seropositive blood donors and more like HTLV seronegative controls in their demographic characteristics and the presence of HTLV risk factors. These results are evidence that volunteer blood donors with isolated and persistent gag seroreactivity in the United States are unlikely to be infected with HTLV-I or HTLV-II.

Until now, serologic tests that distinguish the closely related human T-cell lymphotropic virus types I (HTLV-I) and II (HTLV-II) infections have not been available. Synthetic peptide assays, employing peptides derived from the core and envelope proteins of HTLV-I and HTLV-II (SynthEIA and Select-HTLV tests), were evaluated for the ability to serologically discriminate HTLV-I and HTLV-II infections. Of 32 HTLV-I- and 57 HTLV-II-positive serum specimens from individuals whose infections were confirmed by polymerase chain reaction, the SynthEIA test categorized 29 (91%) as HTLV-I and 50 (88%) as HTLV-II, and 10 (11%) were nontypeable. In contrast, the Select-HTLV test categorized 32 (100%) as HTLV-I and 55 (96%) as HTLV-II, and 2 (2%) were nontypeable. The specificity of both the assays in seropositive serum specimens was 100% in that none of the specimens were incorrectly classified. Additional serum specimens obtained from clinically diseased patients from the United States (n = 8) and asymptomatic carriers and patients from Japan (an endemic population for HTLV-I; n = 40) were categorized as HTLV-I by at least one of the assays, while serum specimens from Guaymi Indians from Panama (an endemic population for HTLV-II; n = 13) were categorized as HTLV-II. Thus, peptide enzyme immunoassays appear to represent a simple technique employing chemically synthesized antigens for discrimination between antibodies of HTLV-I and HTLV-II.

HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is endemic in the Caribbean basin and Japan. Because of the close proximity of the United States to the Caribbean and the presence of HTLV-I-seropositive persons in the United States, we sought reports of patients who were HTLV-I seropositive and had a slowly progressive myelopathy. Over a 2-year period, there were 25 patients reported, 19 of whom were black and 12 of whom had been born in the United States. All patients except two had become symptomatic while living in the United States. Six patients had no apparent risk factor for acquiring HTLV-I. These data demonstrate that HAM/TSP is occurring in the United States and that the diagnosis of HAM/TSP should be considered in patients with a slowly progressive myelopathy regardless of risk factors for acquiring HTLV-I.

To evaluate the usefulness of a human T-cell lymphotropic virus type I (HTLV-I) recombinant p21E immunoassay as a supplementary test in HTLV-I/II serologic testing algorithms, we used this assay to test 378 serum samples previously categorized as positive, indeterminant, or negative for HTLV-I/II antibody, as defined by U.S. Public Health Service guidelines. We found this test to be highly sensitive for detecting antibody to HTLV-I/II env (99.4%) but slightly less specific (96.0%), particularly among samples from intravenous drug users. Our data suggest that this test is most appropriately used to confirm the absence of env antibody in samples which are repeatably reactive in an HTLV-I/II screening assay and gag reactive only by immunoblotting. Because of the high sensitivity of this recombinant p21E test, a negative result in this context could preclude radioimmunoprecipitation testing. However, pending further evaluation of the specificity of this assay, samples testing positive for p21 env antibody may require confirmation by radioimmunoprecipitation, particularly in situations in which the results will be used for diagnostic purposes or blood donor counseling.

To identify risk factors for human T lymphotropic virus type II (HTLV-II) infection in intravenous drug users (IVDUs), participants in a longitudinal study of human immunodeficiency virus (HIV) infection in a New York methadone maintenance program were studied. Of 270 participants tested for HTLV-I/II, 21 (8%) were seropositive. Of those, 15 (71%) had HTLV-II-specific sequences by polymerase chain reaction (PCR) and 1 (5%) had both HTLV-I- and -II-specific sequences; 3 persons with indeterminate serologic results were also PCR-positive for HTLV-II. HTLV-II infection was significantly associated with older age but was not predicted by sex, race, socioeconomic status, transfusion history, or HIV infection status. Behavioral factors since 1978, such as duration and frequency of intravenous drug use, needle sharing, visits to shooting galleries, or number of sex partners, were also not associated with HTLV-II infection. These findings are in contrast with the association of these risk factors with HIV in this group and suggest that, among IVDUs, HTLV-II is an older endemic infection that is less efficiently transmitted than HIV.