An Association of Quality of Life and Ageing Perceptions among Community Dwelling Older Adults in Uganda.

Background: Uganda's population, though, largely characterized by young people, has seen the number of people aged 60 and over grow from 686,000 twenty years ago, to 1,433,596 in 2014. Effective caring for the well-being of this population requires strategic and deliberate planning that involves Quality Of Life (QoL) assessments. QoL assessments among the elderly are important in evaluating the efficacy of strategies, such as health interventions, welfare programs, health care and well-being of the elderly. However, elderly in Uganda face several challenges, ranging from loneliness, poor housing, lack of social and financial support and poor health. These may negatively affect older persons' quality of life and consequently their perceptions and attitudes towards aging. Methods: The study was carried out in 2019 in the communities of Nansana and Busukuma town councils in Wakiso district, Uganda. The participants were 380 people 60 years and older. To establish the association between perceptions of ageing and QoL, this study utilized a locally adapted version of the Older Person's Quality of Life Questionnaire (OPQOL) and the Brief Ageing Perceptions Questionnaire (B-APQ). The OPQOL assesses three domains of QoL: Health QoL (HQoL); Social economic QoL (SQoL); and Psychosocial QoL (PQoL). The B-APQ assesses perceptions about physical age, participation in social activities, and perceptions about ability to regulate emotions as one ages. Pearson's Chi-square tests were used to characterize the relationship between the perceptions and quality of life. Results: The majority of the respondents, 61% (95%CI 56.7-64.8), had negative perceptions towards ageing. Eighty six percent had poor HQoL, 90% poor SQoL and 83% poor PQoL. There was a significant association between good HQoL and positive perception about participation in social activities (X2 = 7.3670, P = 0.007) as well as with positive perception on regulation of emotions (X2 = 18.1803, P<0.001). There was a significant association between good SQoL and positive perception about participation in social activities (X2 = 5.3472, P = 0.021), as well with positive perception on regulation of emotions (X2 = 10.5128, P<0.001). A significant association between good PQoL and positive perception on regulation of emotions (X2 = 9.2414, P= 0.002). Conclusion: Positive perceptions of ageing are associated with good QoL. Directly addressing perceptions of ageing could be a low cost and effective strategy to improve the QoL of older persons in SSA.

Concomitant pulmonary disease is common among patients with extrapulmonary TB.

BACKGROUND: Microbiologic screening of extrapulmonary TB (EPTB) patients could inform recommendations for aerosol precautions and close contact prophylaxis. However, this is currently not routinely recommended in India. Therefore, we estimated the proportion of Indian patients with EPTB with microbiologic evidence of pulmonary TB (PTB).METHODS: We characterized baseline clinical, radiological and sputum microbiologic data of 885 adult and pediatric TB patients in Chennai and Pune, India, between March 2014 and November 2018.RESULTS: Of 277 patients with EPTB, enhanced screening led to the identification of 124 (45%) with concomitant PTB, including 53 (19%) who reported a cough >2 weeks; 158 (63%) had an abnormal CXR and 51 (19%) had a positive sputum for TB. Of 70 participants with a normal CXR and without any cough, 14 (20%) had a positive sputum for TB. Overall, the incremental yield of enhanced screening of patients with EPTB to identify concomitant PTB disease was 14% (95% CI 12-16).CONCLUSIONS: A high proportion of patients classified as EPTB in India have concomitant PTB. Our results support the need for improved symptom and CXR screening, and recommends routine sputum TB microbiology screening of all Indian patients with EPTB.

Comparative clonal analysis of human immunodeficiency virus type 1 (HIV-1)-specific CD4+ and CD8+ cytolytic T lymphocytes isolated from seronegative humans immunized with candidate HIV-1 vaccines.

The lysis of infected host cells by virus-specific cytolytic T lymphocytes (CTL) is an important factor in host resistance to viral infection. An optimal vaccine against human immunodeficiency virus type 1 (HIV-1) would elicit virus-specific CTL as well as neutralizing antibodies. The induction by a vaccine of HIV-1-specific CD8+ CTL in humans has not been previously reported. In this study, CTL responses were evaluated in HIV-1-seronegative human volunteers participating in a phase I acquired immune deficiency syndrome (AIDS) vaccine trial involving a novel vaccine regimen. Volunteers received an initial immunization with a live recombinant vaccinia virus vector carrying the HIV-1 env gene and a subsequent boost with purified env protein. An exceptionally strong env-specific CTL response was detected in one of two vaccine recipients, while modest but significant env-specific CTL activity was present in the second vaccinee. Cloning of the responding CTL gave both CD4+ and CD8+ env-specific CTL clones, permitting a detailed comparison of critical functional properties of these two types of CTL. In particular, the potential antiviral effects of these CTL were evaluated in an in vitro system involving HIV-1 infection of cultures of normal autologous CD4+ lymphoblasts. At extremely low effector-to-target ratios, vaccine-induced CD8+ CTL clones lysed productively infected cells present within these cultures. When tested for lytic activity against target cells expressing the HIV-1 env gene, CD8+ CTL were 3-10-fold more active on a per cell basis than CD4+ CTL. However, when tested against autologous CD4+ lymphoblasts acutely infected with HIV-1, CD4+ clones lysed a much higher fraction of the target cell population than did CD8+ CTL. CD4+ CTL were shown to recognize not only the infected cells within these acutely infected cultures but also noninfected CD4+ T cells that had passively taken up gp120 shed from infected cells and/or free virions. These results were confirmed in studies in which CD4+ lymphoblasts were exposed to recombinant gp120 and used as targets for gp120-specific CD4+ and CD8+ CTL clones. gp120-pulsed, noninfected targets were lysed in an antigen-specific fashion by CD4+ but not CD8+ CTL clones. Taken together, these observations demonstrate that in an in vitro HIV-1 infection, sufficient amounts of gp120 antigen are produced and shed by infected cells to enable uptake by cells that are not yet infected, resulting in the lysis of these noninfected cells by gp120-specific, CD4+ CTL.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibody-mediated clearance of alphavirus infection from neurons.

Humoral immunity is important for protection against viral infection and neutralization of extracellular virus, but clearance of virus from infected tissues is thought to be mediated solely by cellular immunity. However, in a SCID mouse model of persistent alphavirus encephalomyelitis, adoptive transfer of hyperimmune serum resulted in clearance of infectious virus and viral RNA from the nervous system, whereas adoptive transfer of sensitized T lymphocytes had no effect on viral replication. Three monoclonal antibodies to two different epitopes on the E2 envelope glycoprotein mediated viral clearance. Treatment of alphavirus-infected primary cultured rat neurons with these monoclonal antibodies to E2 resulted in decreased viral protein synthesis, followed by gradual termination of mature infectious virion production. Thus, antibody can mediate clearance of alphavirus infection from neurons by restricting viral gene expression.

Delays and barriers to early treatment initiation for childhood tuberculosis in India.

BACKGROUND: India accounts for 27% of global childhood tuberculosis (TB) burden. Understanding barriers to early diagnosis and treatment in children may improve care and outcomes.METHODS: A cross-sectional study was performed among 89 children initiated on anti-TB treatment from a public hospital in Pune during 2016, using a structured questionnaire and hospital records. Health care providers (HCPs) were defined as medical personnel consulted about the child's TB symptoms. Time-to-treatment initiation (TTI) was defined as the number of days between onset of TB symptoms and anti-TB treatment initiation. Based on Revised National TB Control Programme recommendations, delayed TTI was defined as >28 days.RESULTS: Sixty-seven (75%) of 89 enrolled children had significant TTI delays (median 51 days, interquartile range [IQR] 27-86). Sixty-six (74%) children visited 1-8 HCPs in the private sector before approaching the public sector. The median HCP delay was 28 days (IQR 10-75). Bacille Calmette-Guérin vaccination (aOR 10.96, P = 0.04) and loss of appetite (aOR 4.44, P = 0.04) were associated with delayed TTI.CONCLUSION: The majority of the children had TTI delays due to delays by HCPs in the private sector. Strengthening HCP competency in TB symptom screening and encouraging early referrals are crucial for rapid scaling up of early treatment initiation in childhood TB.

Barriers to screening and isoniazid preventive therapy for child contacts of tuberculosis patients.

BACKGROUND: India's guidelines recommend tuberculosis (TB) screening of household contacts aged <6 years and isoniazid preventive therapy (IPT) for children without active disease. We evaluated the current status and barriers to screening and IPT provision among the child contacts of TB patients. METHODS: Questionnaire and health record data were collected from index cases and health care providers (HCPs) at Sassoon General Hospital, Pune, India. RESULTS: Of 80 adult TB cases, 24 (30%) reported that an HCP recommended TB screening of their child contacts; 49/178 (28%) child contacts were screened. Sixteen (33%) children had active TB, and 28 (85%) of those who screened negative were prescribed IPT. Nineteen (76%) HCPs reported recommending child contact screening. Only 8 (32%) reported ever prescribing IPT. Lack of TB screening and IPT provision for child contacts was associated with inadequate HCP counseling (aOR 19.5, P < 0.001), a non-parent index case (aOR 3.72, P = 0.008) and lack of postgraduate HCP qualification (aOR 19.12, P = 0.04). CONCLUSIONS: TB screening and IPT provision for child contacts of adults with TB were infrequent. Many screened children had active TB. Universal, timely TB screening and IPT for exposed children are urgently needed to reduce pediatric TB in India.

Diabetes and pre-diabetes among household contacts of tuberculosis patients in India: is it time to screen them all?

SETTING: Pre-diabetes mellitus (pre-DM) and DM increase the risk of developing tuberculosis (TB). Screening contacts of TB patients for pre-DM/DM and linking them to care may mitigate the risk of developing TB and improve DM management. OBJECTIVE: To measure the prevalence of pre-DM/DM and associated factors among the adult household contacts (HHCs) of pulmonary TB patients. METHODS: Between August 2014 and May 2017, adult HHCs of newly diagnosed adult PTB patients in Pune and Chennai, India, had single blood samples tested for glycosylated haemoglobin (HbA1c) at enrolment. DM was defined as previously diagnosed, self-reported DM or HbA1c 6.5%, and pre-DM as HbA1c between 5.7% and 6.4%. Latent tuberculous infection (LTBI) was defined as a positive tuberculin skin test (5 mm induration) or QuantiFERON® Gold In-Tube (0.35 international units/ml). RESULTS: Of 652 adult HHCs, 175 (27%) had pre-DM and 64 (10%) had DM. Forty (64%) HHCs were newly diagnosed with DM and 48 (75%) had poor glycaemic control (HbA1c 7.0%). Sixty-eight (22%) pre-DM cases were aged 18-34 years. Age 35 years, body mass index 25 kg/m2, chronic disease and current tobacco smoking were significantly associated with DM among HHCs. CONCLUSIONS: Adult HHCs of TB patients in India have a high prevalence of undiagnosed DM, pre-DM and LTBI, putting them at high risk for developing TB. Routine DM screening should be considered among all adult HHCs of TB.

Rate of hospitalization and inpatient care costs for HIV-1-infected patients in Pune, India.

BACKGROUND: The transition of human immunodeficiency virus (HIV) infection to acquired immune deficiency syndrome (AIDS) has begun in India, and an increase in AIDS-related hospitalizations and deaths is an anticipated challenge. We estimated the rates of hospitalization and inpatient care costs for HIV-1-infected patients. METHODS: Data were analysed on 381 HIV-1-infected persons enrolled in a HIV-1 discordant couples' cohort between September 2002 and March 2004. Inpatient care costs were extracted from select hospitals where the study patients were hospitalized and the average cost per hospitalization was calculated. RESULTS: A majority of the patients were in an advanced state of HIV-1 disease with the median CD4 counts being 207 cells/cmm (range: 4-1131 cells/cmm). In all, 63 participants who did not receive antiretroviral therapy required hospitalization, 53 due to HIV-1-related illnesses and the remaining 10 due to worsening of pre-existing conditions. The overall HIV-1-related hospitalization rate was 34.2 per 100 person-years (95% CI: 26.94-42.93). The median duration of HIV-1-related hospitalization was 10 days (range 2-48 days) and the median cost was Rs 17,464 (range: Rs 400-63,891). CONCLUSION: It is necessary to strengthen the inpatient care infrastructure and supporting diagnostic set-up, and work out economically optimized treatment algorithms for HIV-1-infected patients. Although this analysis does not cover all costs and may not be generalizable, these baseline data might be a useful reference while planning related studies accompanying the government-sponsored programme to roll out antiretroviral therapy to AIDS patients.

Feasibility of voluntary counselling and testing services for HIV among pregnant women presenting in labour in Pune, India.

Factors affecting the eligibility and acceptability of voluntary counselling and rapid HIV testing (VCT) were examined among pregnant women presenting in labour in Pune, India. Of the 6702 total women appearing at the delivery room from April 2001 to March 2002, 4638 (69%) were admitted for normal delivery. The remaining women presented with obstetrical complications, delivered immediately or were detected to be in false labour. Overall, 2818 (61%) of the admitted women had been previously tested for HIV during their pregnancy. If previously seen in the hospital's affiliated antenatal clinic, the likelihood of being previously tested was 89%, in contrast to 27% of women having prenatal care elsewhere. Of the admitted women, 3436 (74.3%) were assessed for their eligibility for rapid HIV VCT in the delivery room. Only 1322 (38%) of these women were found to be in early labour and without severe pain or complications, and therefore eligible for rapid HIV screening in the delivery room (DR). Of those 1322 eligible women, only 582 (44%) consented and were tested for HIV, of whom nine (1.6%) were found to be HIV-infected. Of the 1674 women arriving in the DR with no evidence of previous HIV testing, through this DR screening programme, we identified four women with HIV who could now benefit from treatment with ART. Given the high rates of HIV testing in the antenatal clinic at this site and the challenges inherent to conducting DR screening, alternatives such as post-partum testing should be considered to help reduce maternal to infant transmission in this population.

Profile of bone marrow examination in HIV/AIDS patients to detect opportunistic infections, especially tuberculosis.

Morphological evaluation of 140 bone marrow aspirations received in haematopathology laboratory with serologically established HIV infection, along with other relevant special haematological tests, was done during 1st Jan 1999 - 31st Dec 2002 at state government run tertiary care General Hospital in Maharashtra state, India. Out of 140 cases: 118 (84.28%) patients had anaemia, 25 (17.86%) had leukopenia, while 13 (9.28%) were thrombocytopenic. Dyserythropoiesis was present in 18 (12.86%) cases, dysmyelopoiesis 37 (26.43%) and micromegakaryocytes were noted in 44 (31.43%) cases. Haemophagocytosis was evident in 8 (5.71%) cases. Plasmacytosis encountered in 120 (85.71%) cases was a common feature. Based on clinical profile and results of other investigations 56 (40%) patients were clinically diagnosed to be of Mycobacterium tuberculosis (TB). Of these, 18 (12.86%) bone marrow aspirates were positive for AFB, Mycobacterium tuberculosis. In 4 cases cryptococci were demonstrated (Mucicarmine stain). There was one case each of Histoplasma capsulatum and leishmaniasis. One patient showed dense parasitemia with Plasmodium falciparum. One patient had immunoblastic lymphoma and showed bone marrow infiltration. Findings in this study strongly indicate that in HIV/AIDS, AFB stain should be done on each marrow aspirate to rule out tuberculosis in countries like India; where TB and AIDS are marching together.

Vitamin D deficiency and risk of postpartum tuberculosis among HIV-infected breastfeeding mothers in India.

Some studies have associated low vitamin D levels with the risk of tuberculosis (TB), but its association in human immunodeficiency virus (HIV) infected mothers in a TB-endemic region has not been well studied. We conducted a nested 1:2 case-control study among HIV-infected mothers in western India to evaluate the association between maternal vitamin D levels and the risk of postpartum TB. Vitamin D insufficiency, moderate deficiency and severe deficiency were observed in a high proportion of HIV-infected mothers, but were not associated with the risk of postpartum TB.

HIV testing and counseling among men attending sexually transmitted disease clinics in Pune, India: changes in condom use and sexual behavior over time.

OBJECTIVES: To describe changes in sexual behavior and condom use among male heterosexual clients at two public sexually transmitted disease (STD) clinics in Pune, after exposure to HIV testing, counseling, and condom promotion. DESIGN: From 13 May 1993 to 11 April 1997, 6819 heterosexual men were screened for HIV infection as part of the HIV Network for Prevention Trials study. A total of 1628 HIV-seronegative men agreed to return at 3-month intervals for repeated HIV counseling and testing. Counseling at each visit focused on reinforcing messages of monogamy, condom use with sexual partners, and provision of government-provided condoms. METHODS: Data were collected at baseline and at subsequent 3-month intervals, on demographics, previous STD diagnoses, medical history, sexual behavior, knowledge of HIV/AIDS, and practices related to the prevention of HIV. STD were assessed through physical examination and specimen collection, and blood was drawn for HIV-1 and HIV-2 antibody testing. RESULTS: The level of consistent condom use with sex workers increased proportionately with follow-up time: at 6 months men were 2.8 times more likely to consistently use condoms (P < 0.001), at 18 months they were 3.6 times more likely (P < 0.001), and after 24 months they were 4.7 times more likely to be using condoms every time. The risk of HIV seroconversion in men was lowest for those who reported 'always' using condoms (adjusted relative risk, 0.68; P = 0.42; HIV incidence, 4.0) compared with those who reported 'never' using a condom (adjusted relative risk, 2.94; P < 0.001; HIV incidence, 14.0). CONCLUSION: Ongoing counseling and testing was positively associated with risk-reduction behaviors amongst a large proportion of men recruited for this study.

The human immunodeficiency virus epidemic in India. Current magnitude and future projections.

Since the first case of the human immunodeficiency virus (HIV) infection was documented in India in 1986, there has been an explosive increase in HIV transmission. In this review we describe the chronology of the HIV epidemic in India, preliminary information about the clinical presentation of the acquired immunodeficiency syndrome (AIDS), the biological and behavioral aspects of HIV transmission in the Indian setting, and projections regarding the future of the HIV epidemic in India. Using recent data obtained by searching the computerized literature and published abstracts, conference proceedings, and publications from the government of India, we show that India is experiencing a major epidemic of HIV transmission in high-risk populations of commercial sex workers, sexually transmitted disease clinic patients, intravenous drug users, and commercial blood donors. There is also evidence of recent spread of the epidemic from these high-risk groups to other risk groups in India, and from urban centers to rural populations. It is estimated that 1.6 million people are currently infected with HIV in India. At the present rate of transmission, India will have the largest number of HIV-infected individuals of any country in the world by the end of this decade, with more than 5 million infected individuals. Because limited data are available, comprehensive and well-designed epidemiologic surveys are urgently needed to adequately characterize the HIV epidemic in India and to help implement targeted and effective educational and prevention-oriented programs.

PIP: A review of government publications, conference proceedings, and computerized literature and published abstracts reveals an explosive increase in human immunodeficiency virus (HIV) in India since the first case was identified in 1986. In fact, if present rates of transmission persist, India will have more than 5 million HIV-infected persons by the year 2000--the largest number in the world. By 1990, at least 40% of Bombay's 50,000 commercial sex workers were infected. Other high-risk groups include sexually transmitted disease clinic patients, intravenous drug users, and commercial blood donors. The lack of a uniform case definition for AIDS or of a standardized national program to register AIDS cases have impeded research on the natural history of the disease in India. Co-infection with tuberculosis appears to be the predominant clinical pattern. Community awareness of AIDS has been limited by a 50-60% literacy rate, poor access to the mass media in rural areas, and government neglect of AIDS education. Knowledge about HIV and its transmission is alarmingly low, even among health workers. Before 1991, government responses to AIDS were limited to calls for quarantine, the restriction of foreigners, denial of health care to HIV-infected patients, and offers to pay infected prostitutes to retire. Preparation in 1991 of a government document, "Strategic Plan for Prevention and Control of AIDS in India 1992-96," represented a major reversal and a commitment to provide the necessary resources to contain the spread of the epidemic. International aid will be required, however, for the diagnosis and treatment of opportunistic infections, maintenance of an HIV surveillance program, provision of a safe blood supply, prospective studies, and an aggressive educational campaign for health workers and the public.

Optimizing the HIV/AIDS informed consent process in India.

BACKGROUND: While the basic ethical issues regarding consent may be universal to all countries, the consent procedures required by international review boards which include detailed scientific and legal information, may not be optimal when administered within certain populations. The time and the technicalities of the process itself intimidate individuals in societies where literacy and awareness about medical and legal rights is low. METHODS: In this study, we examined pregnant women's understanding of group education and counseling (GEC) about HIV/AIDS provided within an antenatal clinic in Maharashtra, India. We then enhanced the GEC process with the use of culturally appropriate visual aids and assessed the subsequent changes in women's understanding of informed consent issues. RESULTS: We found the use of visual aids during group counseling sessions increased women's overall understanding of key issues regarding informed consent from 38% to 72%. Moreover, if these same visuals were reinforced during individual counseling, improvements in women's overall comprehension rose to 96%. CONCLUSIONS: This study demonstrates that complex constructs such as informed consent can be conveyed in populations with little education and within busy government hospital settings, and that the standard model may not be sufficient to ensure true informed consent.

Chronic active myocarditis following acute Bartonella henselae infection (cat scratch disease).

An association between Bartonella infection and myocardial inflammation has not been previously reported. We document a case of a healthy young man who developed chronic active myocarditis after infection with Bartonella henselae (cat scratch disease). He progressed to severe heart failure and underwent orthotopic heart transplantation. Bartonella henselae, therefore, should be included among the list of infectious agents associated with chronic active myocarditis.

Autologous strain-specific cytolytic T lymphocyte responses directed against human immunodeficiency virus type 1 Env.

The Env glycoprotein of human immunodeficiency virus is critical for the pathogenesis of the acquired immunodeficiency syndrome, and has been the prime target for candidate HIV-1 vaccines. Cytolytic T lymphocytes (CTLs) may be important for the immunologic control of HIV infection and HIV-1 Env-specific cytolytic T cells have been isolated from infected individuals and seronegative recipients of HIV-1 vaccines. Most prior studies have used assays that detect Env-specific CTLs directed against standard laboratory viral variants. These studies may be limited because the Env proteins of these laboratory strains (for example, LAI and MN) may differ significantly from the Env proteins from primary HIV-1 strains, and a single amino acid change can abrogate the recognition of HIV-1 Env by some CTL clones. Therefore, this study measured CTL activity directed against HIV-1 Env representing the infected individual's (autologous) HIV-1 viral variants. For two HIV-1-infected individuals, recombinant vaccina viruses expressing cloned HIV-1 env genes were constructed. Using an in vitro stimulation method, strain-specific CTL activity directed against autologous HIV-1 Env was detected in both individuals. From one subject, strain-specific CTL clones directed against autologous and HIV-1LAI Env were characterized. Therefore, some infected individuals have Env-specific CTLs directed against autologous strains of HIV-1. Detection and characterization of autologous Env-specific CTL activity may have important implications relative to the current HIV-1 vaccine development strategies focusing on Env derived from laboratory strains of HIV-1.

A novel method for detection and ex vivo expansion of HIV type 1-specific cytolytic T lymphocytes.

Studies have shown that cytolytic T lymphocyte (CTL) responses may be critical to the clearance of the early viremia in acute HIV-1 infection. It is likely that these cells play an important role in prolonging the asymptomatic phase of the infection. Although HIV-1-specific CTL activity can be detected in direct assays of freshly isolated peripheral blood lymphocytes (PBL) from some infected individuals, this method fails to detect CTL that are present at low frequency and resting, memory CTL. For these reasons, direct CTL assays on PBL from seropositive individuals may underestimate the level of CTL immunity. As part of ongoing investigations of CTL activity in HIV-1-infected individuals, we developed a novel strategy for the detection and ex vivo expansion of HIV-1-specific CTL. This technique involves selective stimulation of PBL from seropositive individuals with autologous Epstein-Barr virus (EBV)-transformed, B-lymphoblastoid cell lines (B-LCL) infected with vaccinia vectors expressing various HIV-1 genes. Prior to their use for in vitro stimulation, B-LCL are treated with psoralen and UV light to inactivate vaccinia virus. After 1 week of stimulation, CTL activity in stimulated cultures is measured in a standard 51Cr release assay. This ex vivo expansion method can selectively increase the bulk culture CTL activity against env, gag and nef, even in some seropositive individuals with low CD4 counts and little evidence of HIV-1-specific CTL in assays of freshly isolated PBL. These expanded CTL are predominantly of the CD8+ phenotype.(ABSTRACT TRUNCATED AT 250 WORDS)

Clonal analysis of T-cell responses to the HIV-1 envelope proteins in AIDS vaccine recipients.

Both CD4+ and CD8+ CTL responses specific for the HIV-1 envelope proteins can be elicited in seronegative humans by candidate AIDS vaccines. The phenotype of the responding CTL depends upon the nature of the vaccine, with CD8+ CTL being found exclusively in recipients of live virus vaccines. Both types of CTL are active against HIV-1-infected cells in vitro. However, the potential efficacy of vaccine-induced CTL in preventing infection in vaccinated individuals exposed to HIV-1 is unknown and is likely to be dependent upon complex factors including lytic activity against divergent strains, cytokines produced, and the lysis of noninfected CD4+ T cells.