Review of human immunodeficiency virus type 1-related opportunistic infections in sub-Saharan Africa

Incidence of serious morbidity in HIV-infected adults on antiretroviral therapy in a West African care centre, 2003-2008

Background

In resource-limited settings, scaling-up antiretroviral treatment (ART) has required the involvement of decentralized health facilities with limited equipment. We estimated the incidence of serious morbidity among HIV-infected adults receiving ART in one of these HIV routine care center in sub-Saharan Africa.

Methods

We conducted a prospective study at the Centre Medical de Suivi des Donneurs de Sang (CMSDS), which is affiliated with the National Centre for Blood Transfusion in Abidjan, Côte d’Ivoire. Adult patients infected with HIV-1 or HIV-1/HIV-2 who initiated ART between January 2003 and December 2008 were eligible for the study. Standardized clinical data were collected at each visit. Serious morbidity was defined as a new episode of malaria, WHO stage 3–4 event, ANRS grade 3–4 adverse event, or any event leading to death or to hospitalization.

Results

1008 adults, 67% women, with a median age of 35 years, and a median pre-ART CD4 count of 186/mm³ started ART and were followed for a median of 17.3 months. The overall incidences of loss to follow-up, death, and attrition were 6.2/100 person-years (PY) [95% CI 5.1-7.2], 2.3/100 PY [95% CI 1.6-2.9], and 8.1/100 PY [95% CI 7.0-9.4], respectively. The incidence of first serious event was 11.5/100 PY overall, 15.9/100 PY within the first year and 8.3/100 PY thereafter. The most frequently documented specific diagnoses were malaria, tuberculosis, bacterial septicemia and bacterial pneumonia.

Conclusion

Among HIV-infected adults followed in routine conditions in a West African primary care clinic, we recorded a high incidence of serious morbidity during the first year on ART. Providing care centers with diagnostic tools and standardizing data collection are necessary steps to improve the quality of care in primary care facilities in sub-Saharan Africa.

Impact of the National Access to Antiretroviral Program on the incidence of opportunistic infections in Thailand

The National Access to Antiretroviral Program caused a decline in HIV mortality in Thailand, but its impact on opportunistic infections (OI) remains unknown. The aim of this study was to compare the incidence of different OIs before and after the initiation of highly active antiretroviral therapy (HAART). Data from a prospective cohort at a hospital in northern Thailand were analysed. In total, 704 patients enrolled from July 2000 to October 2002 and not on HAART were followed up until October 2004. In addition, 409 patients who started HAART between April 2002 and January 2004 were followed up for 24 months. The impact of HAART on OIs was analysed using Cox proportional hazard models. HAART was associated with a strong reduction in OIs. The reduction appeared to vary by type: tuberculosis (TB), adjusted hazard ratio (AHR) = 0.2 (95% CI 0.1-0.5); pneumocystis pneumonia (PCP), AHR = 0.03 (95% CI 0.007-0.1); cryptococcal meningitis, AHR = 0.2 (95% CI 0.1-0.5); and penicilliosis, AHR = 0.1 (95% CI 0.06-0.3). In conclusion, HAART was very effective in reducing OIs, especially PCP. TB and cryptococcal meningitis remained frequent in the early phase of antiretroviral drug therapy. More attention to prophylaxis as well as earlier diagnosis and starting treatment for these OIs is recommended.

A quantitative structure-activity relationship study of anti-HIV activity of substituted HEPT using nonlinear models

We performed studies on extended series of 79 HEPT ligands (1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine), inhibitors of HIV reverse-transcriptase with anti-HIV biological activity, using quantitative structure–activity relationship (QSAR) methods that imply analysis of correlations and representation of models. A suitable set of molecular descriptors was calculated, and the genetic algorithm was employed to select those descriptors which resulted in the best-fit models. The kernel partial least square and Levenberg–Marquardt artificial neural network were utilized to construct the nonlinear QSAR models. The proposed methods will be of great significance in this research, and would be expected to apply to other similar research fields.

Global Molecular Epidemiology of Cryptococcus neoformans and Cryptococcus gattii: An Atlas of the Molecular Types

Cryptococcosis is a fungal disease affecting more than one million people per year worldwide. The main etiological agents of cryptococcosis are the two sibling species Cryptococcus neoformans and Cryptococcus gattii that present numerous differences in geographical distribution, ecological niches, epidemiology, pathobiology, clinical presentation and molecular characters. Genotyping of the two Cryptococcus species at subspecies level supplies relevant information to understand how this fungus has spread worldwide, the nature of its population structure, and how it evolved to be a deadly pathogen. At present, nine major molecular types have been recognized: VNI, VNII, VNB, VNIII, and VNIV among C. neoformans isolates, and VGI, VGII, VGIII, and VGIV among C. gattii isolates. In this paper all the information available in the literature concerning the isolation of the two Cryptococcus species has been collected and analyzed on the basis of their geographical origin, source of isolation, level of identification, species, and molecular type. A detailed analysis of the geographical distribution of the major molecular types in each continent has been described and represented on thematic maps. This study represents a useful tool to start new epidemiological surveys on the basis of the present knowledge.

Tuberculosis and the risk of opportunistic infections and cancers in HIV-infected patients starting ART in Southern Africa

OBJECTIVES

To investigate the incidence of selected opportunistic infections (OIs) and cancers and the role of a history of tuberculosis (TB) as a risk factor for developing these conditions in HIV-infected patients starting antiretroviral treatment (ART) in Southern Africa.

METHODS

Five ART programmes from Zimbabwe, Zambia and South Africa participated. Outcomes were extrapulmonary cryptococcal disease (CM), pneumonia due to Pneumocystis jirovecii (PCP), Kaposi's sarcoma and Non-Hodgkin lymphoma. A history of TB was defined as a TB diagnosis before or at the start of ART. We used Cox models adjusted for age, sex, CD4 cell count at ART start and treatment site, presenting results as adjusted hazard ratios (aHR) with 95% confidence intervals (CI).

RESULTS

We analysed data from 175,212 patients enrolled between 2000 and 2010 and identified 702 patients with incident CM (including 205 with a TB history) and 487 with incident PCP (including 179 with a TB history). The incidence per 100 person-years over the first year of ART was 0.48 (95% CI 0.44-0.52) for CM, 0.35 (95% CI 0.32-0.38) for PCP, 0.31 (95% CI 0.29-0.35) for Kaposi's sarcoma and 0.02 (95% CI 0.01-0.03) for Non-Hodgkin lymphoma. A history of TB was associated with cryptococcal disease (aHR 1.28, 95% CI 1.05-1.55) and Pneumocystis jirovecii pneumonia (aHR 1.61, 95% CI 1.27-2.04), but not with Non-Hodgkin lymphoma (aHR 1.09, 95% CI 0.45-2.65) or Kaposi's sarcoma (aHR 1.02, 95% CI 0.81-1.27).

CONCLUSIONS

Our study suggests that there may be interactions between different OIs in HIV-infected patients.

Prevalence and clinical features of HIV and malaria co-infection in hospitalized adults in Beira, Mozambique

BACKGROUND

Mozambique presents a very high prevalence of both malaria and HIV infection, but the impact of co-cancel infection on morbidity in this population has been rarely investigated. The aim of this study was to describe the prevalence and clinical characteristics of malaria in hospitalized adult HIV-positive patients, treated and untreated with combination anti-retroviral therapy (ART) and cotrimoxazole (CTX)-based chemoprophylaxis, compared to HIV negatives.

METHODS

From November to December 2010, all adult patients consecutively admitted to the Department of Internal Medicine of Beira Central Hospital, Sofala Province, Mozambique, were submitted to HIV testing, malaria blood smear (MBS) and, in a subgroup of patients, also to the rapid malaria test (RDT). Socio-demographical and clinical data were collected for all patients. The association of both a positive MBS and/or RDT and diagnosis of clinical malaria with concomitant HIV infection (and use of CTX and/or ART) was assessed statistically. Frequency of symptoms and hematological alterations in HIV patients with clinical malaria compared to HIV negatives was also analysed. Sensitivity and specificity for RDT versus MBS were calculated for both HIV-positive and negative patients.

RESULTS

A total of 330 patients with available HIV test and MBS were included in the analysis, 220 of whom (66.7%) were HIV-positive. In 93 patients, malaria infection was documented by MBS and/or RDT. RDT sensitivity and specificity were 94% and 96%, respectively. According to laboratory results, the initial malaria suspicion was discarded in about 10% of cases, with no differences between HIV-positive and negative patients. A lower malaria risk was significantly associated with CTX prophylaxis (p=0.02), but not with ART based on non nucleoside reverse-transcriptase inhibitors (NNRTIs). Overall, severe malaria seemed to be more common in HIV-positive patients (61.7%) compared to HIV-negatives (47.2%), while a significantly lower haemoglobin level was observed in the group of HIV-positive patients (9.9 ± 2.8 mg/dl) compared to those HIV-negative (12.1 ± 2.8 mg/dl) (p=0.003).

CONCLUSIONS

Malaria infection was rare in HIV-positive individuals treated with CTX for opportunistic infections, while no independent anti-malarial effect for NNRTIs was noted. When HIV and malaria co-infection occurred, a high risk of complications, particularly anaemia, should be expected.

Malaria and hiv in adults: when the parasite runs into the virus

Malaria and HIV/AIDS are among the principal causes of morbidity and mortality worldwide, particularly in resource-limited settings such as sub-Saharan Africa. Despite the international community’s efforts to reduce incidence and prevalence of these diseases, they remain a global public health problem. Clinical manifestations of malaria may be more severe in HIV infected patients, which have higher risks of severe malaria and malaria related death. Co-infected pregnant women, children and international travelers from non-malaria endemic countries are at higher risk of clinical complications. However, there is a paucity and conflicting data regarding malaria and HIV co-infection, particularly on how HIV infection can modify the response to antimalarial drugs and about drug-interactions between antiretroviral agents and artemisinin-based combined regimens. Moreover, consulting HIV-infected international travelers and physicians specialized in HIV care and travel medicine should prescribe an adequate chemoprophylaxis in patients travelling towards malaria endemic areas and pay attention on interactions between antiretrovirals and antimalarial prophylaxis drugs in order to prevent clinical complications of this co-infection.

This review aims to evaluate the available international literature on malaria and HIV co-infection in adults providing a critical comprehensive review of nowadays knowledge.

Macroevolutionary Immunology: A Role for Immunity in the Diversification of Animal life

An emerging picture of the nature of immune systems across animal phyla reveals both conservatism of some features and the appearance among and within phyla of novel, lineage-specific defense solutions. The latter collectively represent a major and underappreciated form of animal diversity. Factors influencing this macroevolutionary (above the species level) pattern of novelty are considered and include adoption of different life styles, life histories, and body plans; a general advantage of being distinctive with respect to immune defenses; and the responses required to cope with parasites, many of which afflict hosts in a lineage-specific manner. This large-scale pattern of novelty implies that immunological phenomena can affect microevolutionary processes (at the population level within species) that can eventually lead to macroevolutionary events such as speciation, radiations, or extinctions. Immunologically based phenomena play a role in favoring intraspecific diversification, specialization and host specificity of parasites, and mechanisms are discussed whereby this could lead to parasite speciation. Host switching - the acquisition of new host species by parasites - is a major mechanism that drives parasite diversity and is frequently involved in disease emergence. It is also one that can be favored by reductions in immune competence of new hosts. Mechanisms involving immune phenomena favoring intraspecific diversification and speciation of host species are also discussed. A macroevolutionary perspective on immunology is invaluable in today's world, including the need to study a broader range of species with distinctive immune systems. Many of these species are faced with extinction, another macroevolutionary process influenced by immune phenomena.

Universal screening of Tanzanian HIV-infected adult inpatients with the serum cryptococcal antigen to improve diagnosis and reduce mortality: an operational study

Background

Cryptococcal meningitis is a leading cause of death among HIV-infected individuals in sub-Saharan Africa. Recent developments include the availability of intravenous fluconazole, cryptococcal antigen assays and new data to support fluconazole pre-emptive treatment. In this study, we describe the impact of screening HIV-positive adult inpatients with serum cryptococcal antigen (CRAG) at a Tanzanian referral hospital.

Methods

All adults admitted to the medical ward of Bugando Medical Centre are counseled and tested for HIV. In this prospective cohort study, we consecutively enrolled HIV-positive patients admitted between September 2009 and January 2010. All patients were interviewed, examined and screened with serum CRAG. Patients with positive serum CRAG or signs of meningitis underwent lumbar puncture. Patients were managed according to standard World Health Organization treatment guidelines. Discharge diagnoses and in-hospital mortality were recorded.

Results

Of 333 HIV-infected adults enrolled in our study, 15 (4.4%) had confirmed cryptococcal meningitis and 10 of these 15 (66%) died. All patients with cryptococcal meningitis had at least two of four classic symptoms and signs of meningitis: fever, headache, neck stiffness and altered mental status. Cryptococcal meningitis accounted for a quarter of all in-hospital deaths.

Conclusions

Despite screening of all HIV-positive adult inpatients with the serum CRAG at the time of admission and prompt treatment with high-dose intravenous fluconazole in those with confirmed cryptococcal meningitis, the in-hospital mortality rate remained unacceptably high. Improved strategies for earlier diagnosis and treatment of HIV, implementation of fluconazole pre-emptive treatment for high-risk patients and acquisition of better resources for treatment of cryptococcal meningitis are needed.

Consequences of HIV infection on malaria and therapeutic implications: a systematic review

Despite recent changes in the epidemiology of HIV infection and malaria and major improvements in their control, these diseases remain two of the most important infectious diseases and global health priorities. As they have overlapping distribution in tropical areas, particularly sub-Saharan Africa, any of their clinical, diagnostic, and therapeutic interactions might have important effects on patient care and public health policy. The biological basis of these interactions is well established. HIV infection induces cellular depletion and early abnormalities of CD4+ T cells, decreases CD8+ T-cell counts and function (cellular immunity), causes deterioration of specific antigen responses (humoral immunity), and leads to alteration of innate immunity through impairment of cytolytic activity and cytokine production by natural killer cells. Therefore, HIV infection affects the immune response to malaria, particularly premunition in adolescents and adults, and pregnancy-specific immunity, leading to different patterns of disease in HIV-infected patients compared with HIV-uninfected patients. In this systematic review, we collate data on the effects of HIV on malaria and discuss their therapeutic consequences. HIV infection is associated with increased prevalence and severity of clinical malaria and impaired response to antimalarial treatment, depending on age, immunodepression, and previous immunity to malaria. HIV also affects pregnancy-specific immunity to malaria and response to intermittent preventive treatment. Co-trimoxazole (trimethoprim-sulfamethoxazole) prophylaxis and antiretroviral treatment reduce occurrence of clinical malaria; however, these therapies interact with antimalarial drugs, and new therapeutic guidelines are needed for concomitant use.

Robust substrate profiling method reveals striking differences in specificities of serum and lung fluid proteases

Proteases are candidate biomarkers and therapeutic targets for many diseases. Sensitive and robust techniques are needed to quantify proteolytic activities within the complex biological milieu. We hypothesized that a combinatorial protease substrate library could be used effectively to identify similarities and differences between serum and bronchoalveolar lavage fluid (BALF), two body fluids that are clinically important for developing targeted therapies and diagnostics. We used a concise library of fluorogenic probes to map the protease substrate specificities of serum and BALF from guinea pigs. Differences in the proteolytic fingerprints of the two fluids were striking: serum proteases cleaved substrates containing cationic residues and proline, whereas BALF proteases cleaved substrates containing aliphatic and aromatic residues. Notably, cleavage of proline-containing substrates dominated all other protease activities in both human and guinea pig serum. This substrate profiling approach provides a foundation for quantitative comparisons of protease specificities between complex biological samples.

Difficulty diagnosing chronic cryptococcal meningitis in idiopathic CD4+ lymphocytopenia

A 64-year-old man with idiopathic CD4(+) lymphocytopenia developed cognitive impairment and gait ataxia with isolated obstructive hydrocephalus, which was fatal. Cerebrospinal fluid showed mild pleocytosis, but the etiology was not revealed by extensive analysis. At autopsy, inflammatory cells, CD8(+) lymphocytes and abundant macrophages but not CD4(+) lymphocytes were infiltrating the meninges at the base of the brain. Electron microscopy demonstrated that inflammation was caused by Cryptococcus neoformans, which was localized exclusively within macrophages, where it grew with budding. Our study suggests that, in idiopathic CD4(+) lymphocytopenia, macrophages can efficiently phagocytize but inefficiently digest C. neoformans, thus representing a vehicle of chronic intracellular infection.

HIV/AIDS Clinical Manifestations and their Implication for Patient Clinical Staging in Resource Limited Settings in Tanzania

BACKGROUND

Tanzania HIV/AIDS management follows WHO clinical staging which requires CD4 counts as complement. Lacking CD4 counts facilities in rural health facilities remains a challenge. Simplified and sensitive clinical staging based on local clinical patterns is useful to ensure effective care without CD4 counts.

OBJECTIVES

To assess whether local HIV clinical manifestations can be used to guide HIV management in settings with limited access to CD4 counts in Tanzania.

METHODS

A Cross-sectional study conducted at Tumbi and Chalinze health facilities documented clinical manifestations and CD4 counts in 360 HIV/AIDS patients. Simplified management groups comprised of severe and moderate disease were formed based on clinical manifestations and CD4 counts results. Symptoms with high frequency were used to predict severe disease.

RESULTS

A Weight loss (48.3%) and chronic cough (40.8 %) were the most reported manifestations in the study population. More than 50% of patients presented with CD4≤200. Most symptoms were found to be highly sensitive (71% to 93%) in predicting severe immunosuppression using CD4<200 cut-off point as a 'Gold standard'. Chronic diarrhoea presented in 10.6%, and predicted well severe immunosuppression either alone (OR 1.95, 95%CI, 0.95-4.22) or in combination (OR 4.21, 95%CI 0.92-19.33) with other symptoms. Basing strictly on WHO clinical staging 30.8% of patients were detected to be severely immunosuppressed (Stage 4). While using our proposed management categories of severe and moderate immunosuppression 70% of patients were put into the severe immunosuppression group, consistent with CD4 cut-off count of≤350.

CONCLUSIONS

HIV/AIDS clinics managing large cohorts should develop validated site specific guidelines based on local experiences. Simplified guidelines are useful for resource constrained settings without CD4 counting facilities.

Cryptococcal immune reconstitution inflammatory syndrome in HIV-1-infected individuals: proposed clinical case definitions

Cryptococcal immune reconstitution inflammatory syndrome (IRIS) may present as a clinical worsening or new presentation of cryptococcal disease after initiation of antiretroviral therapy (ART), and is thought to be caused by recovery of cryptococcus-specific immune responses. We have reviewed reports of cryptococcal IRIS and have developed a consensus case definition specifically for paradoxical crytopcoccal IRIS in patients with HIV-1 and known cryptococcal disease before ART, and a separate definition for incident cryptococcosis developed during ART (termed ART-associated cryptococcosis), for which a proportion of cases are likely to be unmasking cryptococcal IRIS. These structured case definitions are intended to aid design of future clinical, epidemiological, and immunopathological studies of cryptococcal IRIS, to standardise diagnostic criteria, and to facilitate comparisons between studies. As for definitions of tuberculosis-associated IRIS, definitions for cryptococcal IRIS should be regarded as preliminary until further insights into the immunopathology of IRIS permit their refinement.

[Prevalence of HIV-TB co-infection and impact of HIV infection on pulmonary tuberculosis outcome in Togo]

The aim of this study was to determine the prevalence of HIV infection in tuberculosis patients and its impact on the TB treatment. We enrolled 569 pulmonary TB patients in four diagnosis and treatment centres in Togo. All patients were new TB cases and received the first-line TB drugs: two months of rifampicin-pyrazinamide-isoniazid-ethambutol and six months of isoniazid-ethambutol. HIV testing was done according to the national guidelines, using rapid diagnosis tests. The CD4 lymphocyte counting was performed by Facscalibur (BD, Sciences) for all HIV-positive patients. Of the 569 TB patients enrolled, 135 (23.7%) were HIV positive (TB/HIV+). HIV prevalence was 22.4% (76 of 339) among men and 25.6% (59 of 230) among women without statistical difference. The global rate of treatment success was 82.2%. The rate of treatment success was lower (64.3%) in TB/HIV+ patients than in TB/HIV- patients (87.5%) (p <0.01). The mortality rates were 25.6% and 11.8% in TB/HIV+ patients and TB/HIV- patients, respectively, with a statistically significant difference (p <0.01). We did not found any statistical difference between the rates of treatment success among TB/HIV- (87.5%) patients and TB/HIV+ patients who had TCD4 lymphocyte counts above 200/µl (84.4%). TB program in Togo must take into account HIV infection to improve its performance.

Pharmacological significance of triazole scaffold

The triazole nucleus is one of the most important and well known heterocycles which is a common and integral feature of a variety of natural products and medicinal agents. Triazole nucleus is present as a core structural component in an array of drug categories such as antimicrobial, anti-inflammatory, analgesic, antiepileptic, antiviral, antineoplastic, antihypertensive, antimalarial, local anaesthetic, antianxiety, antidepressant, antihistaminic, antioxidant, antitubercular, anti-Parkinson's, antidiabetic, antiobesity and immunomodulatory agents, etc. The broad and potent activity of triazole and their derivatives has established them as pharmacologically significant scaffolds. The basic heterocyclic rings present in the various medicinal agents are 1,2,3-triazole and 1,2,4-triazole. A large volume of research has been carried out on triazole and their derivatives, which has proved the pharmacological importance of this heterocyclic nucleus. The present paper is an attempt to review the pharmacological activities reported for triazole derivatives in the current literature with an update of recent research findings on this nuclei.

Malaria parasitemia and CD4 T cell count, viral load, and adverse HIV outcomes among HIV-infected pregnant women in Tanzania

We examined the cross-sectional relationships between malaria parasitemia and CD4 T cell count and viral load among human immunodeficiency virus (HIV)-infected pregnant women. We then followed women to investigate whether or not baseline parasitemia predicted CD4 T cell counts or viral loads > 90 days post-baseline or predicted time to HIV disease stage 3 or 4 or acquired immune deficiency syndrome (AIDS)-related death (ARD). Parasitemia level was nonlinearly associated with viral load at baseline and among measurements taken > 90 days post-baseline; women with low baseline parasitemia, versus none, had higher viral loads at both time points. Any baseline parasitemia predicted an increased rate of ARD among women with baseline CD4 T cell counts > or = 500 cells/microL (ratio rate [RR] = 2.6; 95% confidence interval [CI] = 1.1-6.0; P test for heterogeneity = 0.05). Further study is warranted to determine whether or not parasitemia is especially detrimental to individuals with lower levels of immunosuppression or chronic low parasitemia.

Combination flucytosine and high-dose fluconazole compared with fluconazole monotherapy for the treatment of cryptococcal meningitis: a randomized trial in Malawi

BACKGROUND

Cryptococcal meningitis is a major cause of human immunodeficiency virus (HIV)-associated morbidity and mortality in Africa. Improved oral treatment regimens are needed because amphotericin B is neither available nor feasible in many centers. Fluconazole at a dosage of 1200 mg per day is more fungicidal than at a dosage of 800 mg per day, but mortality rates remain unacceptably high. Therefore, we examined the effect of adding oral flucytosine to fluconazole.

METHODS

From 13 February through 2 December 2008, HIV-seropositive, antiretroviral-naive patients experiencing their first episode of cryptococcal meningitis were randomized to receive (1) 14 days of fluconazole (1200 mg per day) alone or (2) in combination with flucytosine (100 mg/kg per day) followed by fluconazole (800 mg per day), with both groups undergoing 10 weeks of follow-up. The primary end point was early fungicidal activity, derived from quantitative cerebrospinal fluid cultures on days 1, 3, 7, and 14. Secondary end points were safety and 2- and 10-week mortality.

RESULTS

Forty-one patients were analyzed. Baseline mental status, cryptococcal burden, opening pressure, CD4(+) cell count, and HIV load were similar between groups. Combination therapy was more fungicidal than fluconazole alone (mean early fungicidal activity +/- standard deviation -0.28 +/- 0.17 log colony-forming units [CFU]/mL per day vs -0.11 +/- 0.09 log CFU/mL per day; P < .001). The combination arm had fewer deaths by 2 weeks (10% vs 37%) and 10 weeks (43% vs 58%). More patients had grade III or IV neutropenia with combination therapy (5 vs 1, within the first 2 weeks; P = .20), but there was no increase in infection-related adverse events.

CONCLUSIONS

The results suggest that optimal oral treatment for cryptococcal meningitis is high-dose fluconazole with flucytosine. Efforts are needed to increase availability of flucytosine in Africa. Clinical trials registration. isrctn.org Identifier: ISRCTN02725351.

The effect of AIDS defining conditions on immunological recovery among patients initiating antiretroviral therapy at Joint Clinical Research Centre, Uganda

Background

Many HIV-infected patients only access health care once they have developed advanced symptomatic disease resulting from AIDS Defining Conditions (ADCs). We carried out a study to establish the effect of ADCs on immunological recovery among patients initiated on antiretroviral therapy (ART).

Methods

A retrospective cohort of 427 HIV-1 patients who were initiated on ART between January 2002 and December 2006 was studied. Data on ADCs was retrieved from Joint Clinical Research Centre (JCRC) data base and backed up by chart reviews. We employed Kaplan-Meier survival curves to estimate median time to 50 CD4 cells/μl from the baseline value to indicate a good immunological recovery process. Cox proportional hazard models were used at multivariate analysis.

Results

The median time to gaining 50 CD4 cells/μl from the baseline value after ART initiation was longer in the ADC (9.3 months) compared to the non-ADC group (6.9 months) (log rank test, p = 0.027). At multivariate analysis after adjusting for age, sex, baseline CD4 count, baseline HIV viral load, total lymphocyte count and adherence level, factors that shortened the median time to immunological recovery after ART initiation were belonging to the non-ADC group (HR = 1.31; 95% CI: 1.03–1.28, p = 0.028), adherence to ART of ≥ 95% (HR = 2.22; 95% CI: 1.57–3.15, p = 0.001) and a total lymphocyte count ≥ 1200 cells/mm³ (HR = 1.84; 95% CI: 1.22–2.78, p = 0.003). A low baseline CD4 count of ≤ 200 cells/μl (HR = 0.52; 95% CI: 0.37–0.77, p = 0.001) was associated with a longer time to immunological recovery. There was no interaction between low CD4 counts and ADC group.

Conclusion

Patients with ADCs take longer to regain their CD4 counts due to the defect in the immune system. This may prolong their risk of morbidity and mortality.

Osteoarticular tuberculosis in patients with systemic lupus erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) patients are at increased risk of developing tuberculosis (TB), particularly extrapulmonary TB (ExP-TB).

AIM

The present study was undertaken to investigate whether SLE patients showed increased susceptibility to develop osteoarticular TB (OA-TB).

DESIGN AND METHODS

We retrospectively reviewed and compared the frequency of ExP-TB, in particular OA-TB, in patients with SLE at a tertiary hospital in South Africa, to a non-SLE control TB group seen at the same hospital.

RESULTS

TB was diagnosed 111 times in 97 (17%) of the 568 SLE patients. The relative frequency of ExP-TB in the SLE group (25.2%) was significantly lower than in the control group (38.5%) (OR = 1.9, P = 0.006). In contrast, OA-TB was diagnosed in the SLE group in nine (8.1%) patients (seven with peripheral arthritis and two with TB spine) compared to 54 (0.4%) in the overall control group (OR = 20.8, P < 0.001) and 13 (0.2%) in the subgroup of known HIV positive patients in the control group (OR = 44.4, P < 0.001). Within the SLE group, Black ethnicity (P = 0.003), lymphopaenia (P = 0.001), C3/C4 hypocomplementaemia (P = 0.05), corticosteroids [maximum dose (P = 0.002) and duration of treatment (P = 0.02)] and immunosuppressive agents (P = 0.02) were risk factors for TB. Duration of corticosteroid therapy was the only risk factor for OA-TB (P = 0.04).

CONCLUSION

While the relative frequency of ExP-TB was lower in the SLE group compared to the control group, our findings suggest that SLE patients are at particular risk of developing OA-TB. Further prospective studies are needed to better understand the mechanisms that predispose SLE patients to OA-TB.

Burden of cryptococcal meningitis in Malawi

There is little information about the national burden of cryptococcal meningitis (CM) in African countries affected by the HIV/AIDS epidemic. From April 2005 onwards, we used national supervision visits of all health facilities that provided antiretroviral therapy to collect data on the number of new patients diagnosed and treated for CM in the previous quarters - using mainly fluconazole registers. For two 12-month reporting periods, there were 2125 and 2464 patients suffering from CM, giving an estimated annual incidence of 2.2% and 2.6%, respectively, of those infected with HIV in Malawi. Between 40-50% of all patients with CM were diagnosed and treated at central hospitals; no more than 1% were diagnosed and treated at smaller antiretroviral therapy sites. These data are useful for quantifying the need for better diagnostic reagents and antifungal drugs.

A package of primary health care services for comprehensive family-centred HIV/AIDS care and treatment programs in low-income settings

Particularly in resource-limited settings, HIV/AIDS is a family concern. Separate services for children and adults may make accessing care more difficult for families than services where family members can be cared for together. Implicit in comprehensive, family-centred approaches to care are the broader notions of longitudinal primary care and linkages to other services, including those based in communities. As highly-active antiretroviral therapy becomes more available, and the direct burden of HIV-associated morbidity diminishes, HIV-infected individuals require primary care that goes beyond exclusive management of HIV and related conditions, including preventive services and the management of common medical issues. The prevention of tuberculosis, diarrhoea, and, in endemic regions, malaria; the addressing of debilitating depression; cervical screening; and the management of chronic cardiovascular disease and its risk factors are all of benefit to patients accessing HIV/AIDS care. Packaging such services is an effective means both of standardizing care within a program and of ensuring patients receives a full roster of available interventions. As family-centred care models develop in resource-limited settings, the availability of evidence-based service packages such as presented here will help program designers prioritize available human and materiel resources toward those interventions that improve patients' global health and well being.

Efflux-mediated antifungal drug resistance

Fungi cause serious infections in the immunocompromised and debilitated, and the incidence of invasive mycoses has increased significantly over the last 3 decades. Slow diagnosis and the relatively few classes of antifungal drugs result in high attributable mortality for systemic fungal infections. Azole antifungals are commonly used for fungal infections, but azole resistance can be a problem for some patient groups. High-level, clinically significant azole resistance usually involves overexpression of plasma membrane efflux pumps belonging to the ATP-binding cassette (ABC) or the major facilitator superfamily class of transporters. The heterologous expression of efflux pumps in model systems, such Saccharomyces cerevisiae, has enabled the functional analysis of efflux pumps from a variety of fungi. Phylogenetic analysis of the ABC pleiotropic drug resistance family has provided a new view of the evolution of this important class of efflux pumps. There are several ways in which the clinical significance of efflux-mediated antifungal drug resistance can be mitigated. Alternative antifungal drugs, such as the echinocandins, that are not efflux pump substrates provide one option. Potential therapeutic approaches that could overcome azole resistance include targeting efflux pump transcriptional regulators and fungal stress response pathways, blockade of energy supply, and direct inhibition of efflux pumps.

HIV seropositivity predicts longer duration of stay and rehospitalization among nonbacteremic febrile injection drug users with skin and soft tissue infections

BACKGROUND

Skin/soft tissue infections (SSTIs) are the leading cause of hospital admissions among injection drug users (IDUs).

METHODS

We performed a retrospective investigation to determine the epidemiology of SSTIs (ie, cellulitis and/or abscesses) in febrile IDUs, with a focus on bacteriology and potential predictors of increased health care utilization measured by longer length of stay and rehospitalization. Subjects were drawn from a cohort of febrile IDUs presenting to an inner-city emergency department from 1998 to 2004.

RESULTS

Of the 295 febrile IDUs with SSTIs, specific discharge diagnoses were cellulitis only (n = 143, 48.5%), abscesses only (n = 113, 38.3%), and both (n = 39, 13.2%). Documented HIV infection rate was 28%. Of note, 10 subjects were newly diagnosed with HIV infection during their visits. Staphylococcus aureus was the leading pathogen, and increasing rates of methicillin-resistant S. aureus emerged over time (before 2001: 4%, 2001-2004: 56%, P < 0.01). HIV seropositivity predicted rehospitalization within 90 days [adjusted hazard ratios and 95% confidence intervals: 2.90 (1.20 to 7.02)]. HIV seropositivity also predicted increased length of stay in those who were nonbacteremic [adjusted hazard ratios and 95% confidence intervals: 1.49 (1.11 to 2.01)].

CONCLUSIONS

Among febrile IDUs with SSTIs, a strong association between HIV seropositivity and health care resource utilization was found. Accordingly, attention to HIV serostatus should be considered in clinical disposition decisions for this vulnerable high-risk population.

[Clinical manifestations of HIV infection in distinct geographical areas]

The clinical manifestations of HIV infection vary widely in distinct geographical areas. While HIV-related disease has been well characterized in western countries, relatively few publications have described the clinical manifestations of these diseases in tropical areas, where the vast majority of HIV-infected people are concentrated. In addition, HIV infection may alter the natural history of tropical diseases in several ways and tropical diseases influence the course of HIV infection. The present review describes the major opportunistic infections afflicting people with HIV/AIDS in Africa, Latin America, and Asia and discusses the mutual interactions between HIV and the major tropical diseases.

Impact of highly active antiretroviral therapy (HAART) on the incidence of opportunistic infections, hospitalizations and mortality among children and adolescents living with HIV/AIDS in Belo Horizonte, Minas Gerais State, Brazil

The impact of highly active antiretroviral therapy (HAART) can be evaluated using indicators, such as rates of opportunistic infections, hospitalizations by cause of infection, and associated death. This study aimed to estimate the impact of HAART on the incidence of these indicators, in children and adolescents with HIV/AIDS. It was a hybrid cohort study; 371 patients were followed from 1989 to 2003. In December 2003, 76% of the patients were still being followed, while 12.1% had died, 9.5% had dropped out, and 2.4% had been transferred. The overall rate of opportunistic infections was 18.32 infections/100 persons-year and 2.63 in the pre- and post-HAART periods, respectively. In the multivariate analysis, the risk of developing an opportunistic infection was 5.4 times greater and 3.3 times greater for hospitalization risk before HAART. Respiratory causes represented 65% of the hospitalizations and they were reduced by 44.6% with therapeutic intervention. The average hospital stay of 15 days was reduced to 9. There was a post-HAART decline in deaths of 38%. This study demonstrates the effectiveness of HAART in significantly reducing opportunistic infections, hospitalizations, and deaths in this Brazilian cohort.

HIV and malaria co-infection: interactions and consequences of chemotherapy

The global epidemiology of HIV/AIDS and malaria overlap because a significant number of HIV-infected individuals live in regions with different levels of malaria transmission. Although the consequences of co-infection with HIV and malaria parasites are not fully understood, available evidence suggests that the infections act synergistically and together result in worse outcomes. The importance of understanding chemotherapeutic interactions during malaria and HIV co-infection is now being recognized. We know that some antimalarial drugs have weak antiretroviral effects; however, recent studies have also demonstrated that certain antiretroviral agents can inhibit malaria-parasite growth. Here, we discuss recent findings on the impact of HIV/AIDS and malaria co-infection and the possible roles of chemotherapy in improving the treatment of these diseases.

Impact of mating type, serotype, and ploidy on the virulence of Cryptococcus neoformans

Hybridization with polyploidization is a significant biological force driving evolution. The effect of combining two distinct genomes in one organism on the virulence potential of pathogenic fungi is not clear. Cryptococcus neoformans, the most common cause of fungal infection of the central nervous system, has a bipolar mating system with a and alpha mating types and occurs as A (haploid), D (haploid), and AD hybrid (mostly diploid) serotypes. Diploid AD hybrids are derived either from a-alpha mating or from unisexual mating between haploid cells. The precise contributions of increased ploidy, the effect of hybridization between serotypes A and D, and the combination of mating types to the virulence potential of AD hybrids have remained elusive. By using in vitro and in vivo characterization of laboratory-constructed isogenic diploids and AD hybrids with all possible mating type combinations in defined genetic backgrounds, we found that higher ploidy has a minor negative effect on virulence in a murine inhalation model of cryptococcosis. The presence of both mating types a and alpha in AD hybrids did not affect the virulence potential, irrespective of the serotype origin. Interestingly, AD hybrids with only one mating type behaved differently, with the virulence of alphaADalpha strains similar to that of other hybrids, while aADa hybrids displayed significantly lower virulence due to negative epistatic interactions between the Aa and Da alleles of the mating type locus. This study provides insights into the impact of ploidy, mating type, and serotype on virulence and the impact of hybridization on the fitness and virulence of a eukaryotic microbial pathogen.

Predictors of long-term viral failure among ugandan children and adults treated with antiretroviral therapy

BACKGROUND

HIV RNA viral load testing is costly and is generally unavailable in resource-limited settings. We identified predictors of viral failure and documented genotypic mutations in a subset of patients with viral failure after 12 months on antiretroviral therapy (ART).

METHODS

From April 2004 to June 2005, consecutive treatment-naive patients beginning ART at a university clinic in Uganda were enrolled. Clinical information, CD4 cell count, and HIV RNA level were collected at baseline and every 3 to 6 months. Independent predictors of viral failure were identified using multivariate logistic regression. Genotypic drug resistance for 8 patients with viral failure at 12 months was measured at baseline and at 6 and 12 months.

RESULTS

Five hundred twenty-six adults and 250 children (0 to 18 years of age) were started on first-line ART regimens and followed for 12 months. Outcomes could not be assessed in 13% of patients (79 died and 21 were withdrawn). Children were almost twice as likely to have viral failure compared with adults (26% vs. 14%; P = 0.0001). In adults, the sole independent predictor of viral failure was treatment with stavudine (d4T)/lamivudine (3TC)/nevirapine (NVP) versus zidovudine (ZDV)/3TC/efavirenz (EFV) (odds ratio [OR] = 2.59, 95% confidence interval [CI]: 1.20 to 5.59). In children, independent predictors of viral failure included male gender (OR = 2.44, 95% CI: 1.20 to 4.93), baseline CD4% <5 (OR = 2.69, 95% CI: 1.28 to 5.63), and treatment with d4T/3TC/NVP versus ZDV/3TC/EFV (OR = 2.46, 95% CI: 1.23 to 4.90). All 8 patients with viral breakthrough and genotypic drug resistance results had nonnucleoside reverse transcriptase inhibitor (NNRTI)- and 3TC-associated mutations.

CONCLUSIONS

These data demonstrate the effectiveness of ART in a low-resource setting. Children and patients of all ages taking the d4T/3TC/NVP regimen were more likely to have viral failure. Our data suggest that viral failure occurring 6 months or more after the start of ART regimens commonly used in Uganda is likely to be associated with NNRTI- and 3TC-resistant virus.

How a different look at latency can help to develop novel diagnostics and vaccines against tuberculosis

Mycobacterium tuberculosis is one of the most successful human pathogens. It kills every year approximately 1.5 - 2 million people, and at present a third of the human population is estimated to be infected. Fortunately, only a relatively small proportion of the infected individuals will progress to active disease, and most will maintain a latent infection. Although a latent infection is clinically silent and not contagious, it can reactivate to cause highly contagious pulmonary tuberculosis, the most prevalent form of the disease in adults. Therefore, a thorough understanding of latency and reactivation may help to develop novel control strategies against tuberculosis. The most widely held view is that the mycobacteria are imprisoned in granulomatous structures during latency, where they can survive in a non-replicating, dormant form until reactivation occurs. However, there is no hard data to sustain that the reactivating mycobacteria are indeed those that laid dormant within the granulomas. In this review an alternative model, based on evidence from early studies, as well as recent reports is presented, in which the latent mycobacteria reside outside granulomas, within non-macrophage cell types throughout the infected body. Potential implications for new diagnostic and vaccine design are discussed.

HIV-associated Isospora belli infection: incidence and risk factors in the French Hospital Database on HIV

OBJECTIVE

To determine the incidence of Isospora belli infection in HIV-infected patients in France, and to study risk factors.

METHODS

The French Hospital Database on HIV (FHDH) is a prospective cohort study that collects demographic, clinical and therapeutic data on patients managed in 62 hospitals. We reviewed all cases of I. belli infection recorded between 1992 and 2003. We compared the incidence in 1992-1994 [before the use of dual therapy and combination antiretroviral therapy (cART)] and in 1997-2003 (when use of cART was widespread), after stratification for CD4 cell count (< 50, 50-99, 100-199 and > 200 cells/microL).

RESULTS

A total of 164 patients had I. belli infection either at enrollment (n=71) or during follow up (n=93). During the study period, I. belli infection tended to occur less frequently during follow up, and to be diagnosed mainly at database enrollment. The incidence of I. belli infection during follow up fell by 79% [relative hazard (RH) 0.21; 95% confidence interval (CI) 0.13-0.33] in the cART period compared with the pre-cART period; no such change was noted among patients with CD4 cell counts below 50 cells/microL. In multivariable analysis, the risk of I. belli infection was significantly higher among patients from sub-Saharan Africa (RH 4.3; 95% CI 2.6-7.3). After adjustment for CD4 cell count, patients receiving cotrimoxazole prophylaxis were found to be at a lower risk of I. belli infection (RH 0.3; 95% CI 0.2-0.6).

CONCLUSIONS

In France, I. belli infection among HIV-infected patients is now mainly seen in patients from sub-Saharan Africa, who present at an advanced stage.

Epidemiologic and clinical characteristics of HIV/AIDS patients in Turkey, where the prevalence is the lowest in the region

The authors describe the epidemiologic and clinical characteristics of 97 human immunodeficiency virus (HIV)-infected patients, who were followed between 1993 and 2006. Seventy-two percent of the patients were male, and median age at diagnosis was 36 years (range, 13-71 years). The mean years of survival was 3, and maximum length of life after diagnosis was 9 years. The most common professions were truck drivers, workers, and housewives. Forty-six percent of the males had a history of working abroad. Heterosexual intercourse was the most common (84%) route of transmission. Seventy-four percent of the women acquired infection from their husbands. In Turkey, less educated or uneducated and poor men are the primary target of the HIV infection usually by sexual contact with foreign women. Considering the low education status of the patients, appropriate education programs should be developed to prevent the dissemination of HIV infection. Because a significant number of patients were diagnosed at very late stages, the physicians and other health care workers should be educated on the clinical pictures of HIV/AIDS.

Asymptomatic serum cryptococcal antigenemia and early mortality during antiretroviral therapy in rural Uganda

OBJECTIVE

To evaluate the association between a positive serum cryptococcal antigen (CRAG) test at baseline and mortality during the first 12 weeks on antiretroviral therapy (ART). Cryptococcal meningitis is a leading cause of HIV-related mortality in Africa, but current guidelines do not advocate CRAG testing as a screening tool.

METHODS

Between May 2003 and December 2004, we enrolled HIV-1 infected individuals into a study of ART monitoring in rural Uganda. CRAG testing was conducted retrospectively on stored pre-ART serum samples of participants whose baseline CD4 cell count was <100 cells/mul and who were without symptoms suggestive of disseminated cryptococcal disease at enrolment.

RESULTS

Of 377 participants, 5.8% had serum CRAG titre >/=1:2. Of these, 23% died during follow-up. Controlling for CD4 cell count, HIV-1 viral load, anaemia, active tuberculosis and body mass index, relative risk of death during follow-up among those with asymptomatic cryptococcal antigenemia at baseline was 6.6 [95% confidence interval (CI) 1.86-23.61, P = 0.0036]. The population attributable risk for mortality associated with a positive CRAG at baseline was 18% (CI 2-33%), similar to that associated with active tuberculosis (19%, CI 1-36%).

CONCLUSION

Asymptomatic cryptococcal antigenemia independently predicts death during the first 12 weeks of ART among individuals with advanced HIV disease in rural Uganda. Routine screening and provision of azole antifungal therapy prior to or simultaneous with the start of ART should be evaluated for the potential to prevent mortality in this population.

Tuberculosis: Diagnostics

While microscopy and culture are still the major backbone for laboratory diagnosis of tuberculosis (TB), new methods including molecular diagnostic tests have evolved over the last two decades. The majority of molecular tests have been focused on: (i) detection of nucleic acids both DNA and RNA, which are specific to Mycobacterium tuberculosis, by amplification techniques such as polymerase chain reaction (PCR); and (ii) detection of mutations in the genes which are associated with resistance to anti-tuberculosis drugs by sequencing or nucleic acid hybridization. In the session of the conference on diagnosis of TB, there were two presentations: one on the development of new diagnostic tools for drug resistant M. tuberculosis, and the other on issues involved in the application of new diagnostic tools for multidrug resistant (MDR)-TB, pediatric TB and HIV-TB.

HIV infection mimicking autoimmune disorder

A 13-yr-old girl born to healthy parents presented with cough, fever, easy fatiguability, photosensitivity and alopecia. She had clubbing and diffuse crackles in the chest on examination. Her CT scan of the chest showed evidence of bronchiectasis with consolidation. Investigations for tuberculosis and collagen vascular disease were negative. In due course she developed features of raised intracranial tension. Her blood for HIV ELISA was positive with CD4 counts of 17/ microL. Her CSF, sputum, blood and urine specimen were all positive for Cryptococcus neoformans on culture. HIV was not considered initially because of her atypical presentation. There was no history of sexual abuse, her parents were healthy and she did not receive any blood transfusion in the past.

The Independent Effect of Highly Active Antiretroviral Therapy on Severe Opportunistic Disease Incidence and Mortality in HIV-Infected Adults in Côte D'Ivoire

Background

Studies in developed countries have shown highly active antiretroviral therapy (HAART) decreases incidence of severe opportunistic diseases (ODs) in HIV-infected patients beyond that which is expected from changes in CD4+T-cell count.

Objective

To estimate the independent impact of HAART on reducing ODs and mortality in Côte d'Ivoire.

Methods

Within two longitudinal studies of HIV-infected adults (1996–2003), we identified time on ‘cotrimoxazole alone’ and ‘HAART plus cotrimoxazole’. WHO stage 3–4 defining events and severe malaria were divided into those preventable and not preventable with cotrimoxazole. Incidence of ODs by CD4 count stratum was estimated using incidence density analysis. CD4+ T-cell count at time of OD was estimated using linear interpolation. Using Poisson regression, we estimated the effect of HAART on OD incidence and mortality by CD4 count stratum.

Results

Totals of 446 and 135 adults were followed during 6,216 and 3,412 person-months in the cotrimoxazole alone and HAART plus cotrimoxazole periods, respectively. There was a CD4+ T-cell-independent risk reduction for ODs and mortality during the HAART plus cotrimoxazole period compared with cotrimoxazole alone, which varied by time on HAART, CD4 count stratum and OD type. It was mainly seen after 6 months on HAART and for ODs not preventable by cotrimoxazole. The HAART effect differed significantly by CD4 count stratum ( P=0.02), but was significant in all strata after 6 months on HAART.

Conclusions

In these sub-Saharan African adults, HAART initiation reduced ODs and mortality beyond that which was expected through the HAART-induced CD4+ T-cell increase. Further studies should examine practical implications of this independent ‘HAART effect’ on clinical outcomes in patients on HAART.

Discordant Responses to Potent Antiretroviral Treatment in Previously Naive HIV-1-Infected Adults Initiating Treatment in Resource-Constrained Countries

OBJECTIVES

To assess the frequency of and risk factors for discordant responses at 6 months on highly active antiretroviral therapy (HAART) in previously treatment-naive HIV patients from resource-limited countries.

METHODS

The Antiretroviral Therapy in Low-Income Countries Collaboration is a network of clinics providing care and treatment to HIV-infected patients in Africa, Latin America, and Asia. Patients who initiated therapy between 1996 and 2004, were aged 16 years or older, and had a baseline CD4 cell count were included in this analysis. Responses were defined based on plasma viral load (PVL) and CD4 cell count at 6 months as complete virologic and immunologic (VR(+)IR(+)), virologic only (VR(+)IR(-)), immunologic only (VR(-)IR(+)), and nonresponse (VR(-)IR(-)). Multinomial logistic regression was used to assess the association between therapy responses and clinical and demographic variables.

RESULTS

Of the 3111 patients eligible for analysis, 1914 had available information at 6 months of therapy: 1074 (56.1%) were VR(+)IR(+), 364 (19.0%) were VR(+)IR(-), 283 (14.8%) were (VR(-)IR(+)), and 193 (10.1%) were VR(-)IR(-). OF THE 3111 patients eligible for analysis, 1914 had available information at 6 months of therapy: 1074 (56.1%) were VRIR, 364 (19.0%) were VRIR, 283 (14.8%) were (VRIR), and 193 (10.1%) were VRIR. Compared with complete responders, virologic-only responders were older, had a higher baseline CD4 cell count, had a lower baseline PVL, and were more likely to have received a nonstandard HAART regimen; immunologic-only responders were younger, had a lower baseline CD4 cell count, had a higher baseline PVL, and were more likely to have received a protease inhibitor-based regimen.

CONCLUSIONS

The frequency of and risk factors for discordant responses were comparable to those observed in developed countries. Longer follow-up is needed to assess the long-term impact of discordant responses on mortality in these resource-limited settings.

Prevalence, incidence and mortality associated with tuberculosis in HIV-infected patients initiating antiretroviral therapy in rural Uganda

BACKGROUND

Tuberculosis (TB) is the leading cause of death among people with HIV in sub-Saharan Africa. Expanding access to antiretroviral therapy (ART) may reduce the burden of TB, but to what extent is unknown.

METHODS

In a study of 1044 adults who initiated home-based ART in Tororo, Uganda between 1 May 2003 and 30 June 2005, participants were screened for active TB at baseline and then monitored at weekly home visits. Participants with TB at baseline or follow-up were compared with those without TB to determine factors associated with mortality in those with TB.

RESULTS

At baseline, 75 (7.2%) subjects had TB and a total of 53 (5.5%) were diagnosed with TB over a median of 1.4 years of follow-up (3.90 cases/100 person years). Cumulative mortality was 17.9/100 person-years for those with TB and 3.8/100 person-years for those without TB (P < 0.001). Mortality was associated with low baseline CD4 cell counts [relative hazard (RH), 0.99 per 1 cell/microl increase; P = 0.03] and marginally associated with a body mass index <or= 18 (RH, 2.04; P = 0.10) and increasing age (RH, 1.04 per year; P = 0.11). TB incidence and TB-associated mortality were highest within the first 6 months of ART and declined to 52% and 61% of expected values, respectively, from months 7 to 18 after ART initiation.

CONCLUSION

TB remains an important cause of illness and death in patients receiving ART in Uganda. However, both appear to decline markedly, after 6 months of ART.

Is HIV-2- induced AIDS different from HIV-1-associated AIDS? Data from a West African clinic

BACKGROUND

Although AIDS is less frequent following HIV-2 than HIV-1 infection, it is unclear whether the clinical picture and clinical course of AIDS are similar in the two infections.

OBJECTIVES

To compare the pattern of AIDS-defining events, CD4 cell count at the time of AIDS diagnosis, survival from time of AIDS, and CD4 cell count near time of death in HIV-1 and HIV-2-infected patients.

METHODS

Adult patients with AIDS who attended the clinics of the MRC in The Gambia were enrolled. AIDS was diagnosed according to the expanded World Health Organization case definition for AIDS surveillance (1994).

RESULTS

Three hundred and forty-one AIDS patients with HIV-1 and 87 with HIV-2 infection were enrolled. The most common AIDS-defining events in both infections were the wasting syndrome and pulmonary tuberculosis. The median CD4 cell count at AIDS was 109 cells/microl in HIV-1 and 176 in HIV-2 (P = 0.01) and remained significantly higher in HIV-2 after adjustment for age and sex (P = 0.03). The median time to death was 6.3 months in HIV-1 and 12.6 months in HIV-2-infected patients (P = 0.03). In a multivariable analysis adjusting for age, sex and CD4 cell count, the mortality rates of HIV-1 and HIV-2-infected patients were similar (P = 0.25). The median CD4 cell count near time of death was 62 and 120 cells/microl in HIV-1 and HIV-2-infected patients, respectively (P = 0.02).

CONCLUSIONS

HIV-2 patients have a higher CD4 cell count at the time of AIDS, and a longer survival after AIDS. The mortality after an AIDS diagnosis is more influenced by CD4 cell count than HIV type.

The biology of the Cryptococcus neoformans species complex

Cryptococcus neoformans is a major cause of fungal meningoencephalitis in immunocompromised patients. Despite recent advances in the genetics and molecular biology of C. neoformans, and improved techniques for molecular epidemiology, aspects of the ecology, population structure, and mode of reproduction of this environmental pathogen remain to be established. Application of recent insights into the life cycle of C. neoformans and its different ways of engaging in sexual reproduction under laboratory conditions has just begun to affect research on the ecology and epidemiology of this human pathogenic fungus. The melding of these disparate disciplines should yield rich dividends in our understanding of the evolution of microbial pathogens, providing insights relevant to diagnosis, treatment, and prevention.