The mortality and pathology of HIV infection in a west African city

Maternal death, autopsy studies, and lessons from pathology

The author discusses the implications of a new autopsy study of maternal deaths in Mozambique.

Cause of death and presence of respiratory disease at autopsy in an HIV-1 seroconversion cohort of southern African gold miners

OBJECTIVES

To describe causes of death and respiratory infections in HIV-infected miners in the pre-antiretroviral era, by duration of HIV infection.

DESIGN

A retrospective cohort of 1950 gold miners with known dates of HIV seroconversion and 6164 HIV-negative miners was followed from the early 1990s to 2002.

METHODS

Causes of death were available from multiple sources: personnel records, clinical records, death certificates and autopsies of cardiorespiratory organs performed for compensation purposes.

RESULTS

Causes of death were known for 279 of 308 HIV-positive (91%) and 234 of 254 HIV-negative (92%) men who died while employed or within 6 months of leaving employment. The mortality rate from unnatural causes was similar in HIV-positive and HIV-negative miners and by duration of HIV infection. Among deaths from natural causes, 87% in HIV-positive and 41% in HIV-negative individuals were caused by infection (P < 0.001); 47% of HIV-positive and 26% of HIV-negative individuals had tuberculosis. The proportion of deaths from natural causes with any infection, or with specific infections (tuberculosis, cryptococcus, pneumocystis), did not vary with the duration of HIV infection. Autopsies were performed on 29% of men who died from natural causes: 83% of HIV-positive and 37% of HIV-negative men had respiratory infections (P < 0.001), half of which were clinically undiagnosed.

CONCLUSION

Tuberculosis was the leading cause of death in HIV-positive and negative men who died from natural causes. Although the mortality rate from natural causes increased greatly with the duration of HIV infection, the pattern of disease hardly changed, suggesting that slow and fast progressors succumb to the same range of diseases.

Multiplex PCR with minisequencing as an effective high-throughput SNP typing method for formalin-fixed tissue

Extensive collections of formalin-fixed paraffin-embedded (FFPE) tissues exist that could be exploited for genetic analyses in order to provide important insights into the genetic basis of disease or host/pathogen cointeractions. We report here an evaluation of a 44 SNP multiplex genotyping method, multiplex PCR with minisequencing (MPMS), on 92 DNA extractions performed on six archival FFPE samples of variable DNA quality, which date between 9 and 25 years old. On the three extracts with highest quality, we found the assay efficiency to be near 100%. However, the efficiency of the lowest quality extracts varied significantly. In this study, we demonstrate that although direct measures of DNA concentration in the extracts provide no useful information with regard to subsequent MPMS success, the success of the assay can be determined to some degree a priori, through initial screening of the DNA quality using a simple quantitative real-time PCR (qPCR) assay for nuclear DNA, and/or an assay of the maximum PCR amplifiable size of nuclear DNA. MPMS promises to be of significant use in future genetic studies on FFPE material. It provides a streamlined approach for retrieving a large amount of genetic information using simple, single reactions and minute amounts of archival tissue/DNA. In the light of this evidence, we suggest that the systematic screening of FFPE collections may in the future provide valuable insights into the past.

Prevalence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in goats slaughtered in the public slaughterhouse of Patos city, Paraíba State, Northeast region of Brazil

The prevalence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies was investigated in goats slaughtered in the public slaughterhouse of Patos, State of Paraíba, Northeast region of Brazil, and possible associations between sex of the animals and antibody prevalence were verified. Three-hundred six blood samples from goats collected before slaughter by jugular venopuncture were used. For the serologic diagnosis of T. gondii and N. caninum, the indirect fluorescent-antibody test (IFAT) with cut-off values 64 and 50, respectively, was carried out. The prevalence of anti-T. gondii antibodies was 24.5% [95% CI=19.8-29.7%] with titers ranging from 64 to 4096, and anti-N. caninum antibodies was 3.3% (95% CI=1.6-5.9%) with titers ranging from 50 to 400. There were no associations between sex of animals and prevalence of anti-T. gondii and anti-N. caninum antibodies.

Causes of death in hospitalized adults with a premortem diagnosis of tuberculosis: an autopsy study

OBJECTIVE

To ascertain the immediate and underlying causes of death in adults who died in hospital with a premortem diagnosis of tuberculosis.

DESIGN

Causes of death were assessed independently by internists and pathologists in 50 adults admitted to two Soweto hospitals who died 24 h or more after admission. Detailed record reviews and complete autopsies, including HIV tests when not performed premortem, were performed. In addition, a variety of postmortem microbiological tests were performed.

RESULTS

Forty-seven patients had HIV infection; all were antiretroviral naive. Their median age was 34.5 years, median CD4 cell count was 48 cells/microl and median length of hospitalization before death was 6 days. Autopsy confirmed the premortem diagnosis of tuberculosis in 37 HIV-infected patients (79%), whereas 10 (21%) did not demonstrate tuberculosis. Bronchopneumonia and cytomegalovirus pneumonitis were the leading pathologies in these 10 patients. In 47 HIV-infected cadavers immediate or contributory causes of death were: extensive pulmonary tuberculosis, 32 (68%); disseminated tuberculosis, 28 (60%); bacterial pneumonia, 13 (26%); cytomegalovirus pneumonitis in seven (15%); cytomegalovirus DNA was found in 31 (66%) and Pneumocystis pneumonia was found in five cadavers (11%). The lung, followed by lymph nodes, liver and kidney, were the commonest sites of tuberculosis. Mycobacterium tuberculosis was cultured from 19 spleens, one of which was multidrug resistant, and Salmonella spp. was cultured from 11 splenic specimens.

CONCLUSION

We demonstrated disseminated, extensive tuberculosis associated with advanced HIV disease. Severe bacterial infections, including salmonellosis, were the leading co-morbidity, suggesting that hospitalized HIV-infected adults in whom tuberculosis is suspected may benefit from broad-spectrum antibiotic therapy.

Facing the crisis: improving the diagnosis of tuberculosis in the HIV era

Although the human immunodeficiency virus (HIV) infection pandemic has had a catastrophic impact on tuberculosis (TB) control efforts, especially in sub-Saharan Africa, most of the fundamental concepts reflected in the directly observed treatment, short course (DOTS) strategy still hold true in the HIV era. What has changed, and dramatically, is the importance of speedy and accurate TB diagnosis and the difficulty of achieving this. The disproportionate amount of smear-negative disease in sub-Saharan Africa, which shoulders two-thirds of the global burden of HIV infection and acquired immunodeficiency syndrome, has greatly complicated TB case detection and disease control. Now, 15 years after TB rates began to soar in countries where HIV infection is prevalent, we have learned that the conventional approach -- passively waiting for patients with advanced symptomatic disease to make their way to microscopy centers for diagnosis -- has disastrous consequences. Without better diagnostic tools for TB and effective strategies for their implementation, transmission will not be interrupted, mortality will not be checked, and TB will not be controlled in areas where HIV infection is prevalent. Fortunately, a number of technical opportunities exist for the creation of improved diagnostic tests. Developing and exploiting such tests to support TB control in HIV-infected populations is an urgent priority. A substantial public sector effort is under way to work in partnership with the biotechnology industry to accelerate progress toward that goal. In this article, we will define the need for better TB tests and describe technologies being developed to meet that need.

Pneumocystis jiroveci pneumonia and other pulmonary infections in TB smear-negative HIV-positive patients with atypical chest X-ray in Ethiopia

Pneumocystis pneumonia (PCP) has been considered a rare disease in sub-Saharan Africa. However, a rising prevalence has been noted recently. The objective of this study was to determine the relative prevalence of PCP and other pulmonary opportunistic diseases in patients infected with HIV in Ethiopia. 131 consecutive patients with respiratory symptoms and atypical chest X-ray, who were sputum smear-negative for AFB and seroreactive for HIV, underwent clinical evaluation and investigation for Pneumocystis jiroveci and Mycobacterium tuberculosis from sputum and bronchoalveolar lavage (BAL), and fungal and bacterial pathogens from BAL alone. Bacterial infections, Pneumocystis pneumonia (PCP) and pulmonary tuberculosis (PTB) occurred in 44 (33.6%), 39 (29.7%) and 31 (23.7%) patients, respectively. Pulmonary Kaposi sarcoma and non-specific interstitial pneumonitis occurred in 4 patients each. In a multivariate regression model, predictors of PCP were typical chest X-ray and low CD4 count while purulent sputum predicted bacterial infection. The sensitivity of physicians and chest X-ray diagnosis was particularly low for PTB and bacterial infections. We conclude that chronic bacterial infection and Pneumocystis pneumonia are important differential diagnoses in HIV-infected, smear-negative PTB patients presenting with atypical chest X-ray. We therefore need to escalate the use of preventive and highly active antiretroviral (HAART) treatment in order to prevent a PCP epidemic.

Tuberculosis and HIV Infection: The Global Setting

Tuberculosis (TB) and human immunodeficiency virus (HIV) infection make each other's control significantly more difficult. Coordination in addressing this "cursed duet" is insufficient at both global and national levels. However, global policy for TB/HIV coordination has been set, and there is consensus around this policy from both the TB and HIV control communities. The policy aims to provide all necessary care for the prevention and management of HIV-associated TB, but its implementation is hindered by real technical difficulties and shortages of resources. All major global-level institutions involved in HIV care and prevention must include TB control as part of their corporate policy. Country-level decision makers need to work together to expand both TB and HIV services, and civil society and community representatives need to hold those responsible accountable for their delivery. The TB and HIV communities should join forces to address the health-sector weaknesses that confront them both.

Fulminant toxoplasmosis causing fatal pneumonitis and myocarditis

The obligate intracellular protozoa Toxoplasma gondii is a serious cause of morbidity and mortality in patients with AIDS. Toxoplasmosis most frequently manifests as life-threatening encephalitis, although extracerebral sites may be involved with or without toxoplasmic encephalitis. Consequently, toxoplasmosis can present in an unusual manner, and may not be included in the differential diagnosis in the absence of encephalitic symptoms. There are few reports of fulminant toxoplasmic myocarditis resulting in death. Toxoplasmic pneumonitis is responsible for less than 1% of HIV-related pulmonary complications, and can occasionally cause fatal septic shock. Two such clinicopathological presentations of toxoplasmosis are reported here. One patient presented with cardiorespiratory signs and symptoms, whilst the second patient presented with pneumonitis and renal failure. Neither patient was initially known to be HIV-infected, nor did they have clinical symptoms indicating toxoplasmic encephalitis. Toxoplasmosis was only diagnosed on autopsy and had resulted in death by causing a fulminant myocarditis and a pneumonitis. As overwhelming toxoplasmosis infection may prove rapidly fatal, these two case reports serve as a clinical reminder to consider toxoplasmosis in the differential diagnosis of HIV-infected patients who present with severe cardiorespiratory signs and symptoms. Furthermore, the cases emphasize the potential importance of early tissue biopsy in patients presenting with immunosuppression-associated organ failure, and show the importance of requesting a postmortem examination if the cause of death cannot be ascertained in vivo.

Progression to WHO criteria for antiretroviral therapy in a 7-year cohort of adult HIV-1 seroconverters in Abidjan, Côte d'Ivoire

OBJECTIVE

To estimate the probability of reaching the criteria for starting highly active antiretroviral therapy (HAART) in a prospective cohort of adult HIV-1 seroconverters in Abidjan, Côte d'Ivoire.

METHODS

We recruited participants from HIV-positive donors at the blood bank of Abidjan for whom the delay since the estimated date of seroconversion (midpoint between last negative and first positive HIV-1 test) was < 36 months. Participants were offered early trimethoprim-sulfamethoxazole (cotrimoxazole) prophylaxis, twice-yearly measurement of CD4 count and we made standardized records of morbidity. We used the Kaplan-Meier method to estimate the probability of reaching the criteria for starting HAART according to WHO 2006 guidelines.

FINDINGS

217 adults (77 women (35%)) were followed up during 668 person-years (PY). The most frequent diseases recorded were mild bacterial diseases (6.0 per 100 PY), malaria (3.6/100 PY), herpes zoster (3.4/100 PY), severe bacterial diseases (3.1/100 PY) and tuberculosis (2.1/100 PY). The probability of reaching the WHO 2006 criteria for HAART initiation was estimated at 0.09, 0.16, 0.24, 0.36 and 0.44 at 1, 2, 3, 4 and 5 years, respectively.

CONCLUSION

Our data underline the incidence of the early HIV morbidity in an Ivorian adult population and provide support for HIV testing to be made more readily available and for early follow-up of HIV-infected adults in West Africa.

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.

Helminths and HIV infection: epidemiological observations on immunological hypotheses

Parasitic helminths have co-evolved with the mammalian immune system. Current hypotheses suggest that immunological stimulation in the presence of helminths is balanced by immuno-regulation and by the broad spectrum of mechanisms possessed by helminths for countering the host immune response. The degree to which this balance is perfected, and the mechanisms by which this is achieved, vary between helminth species; we suggest that this is reflected not only in the degree of pathology induced by helminths but also in a variety of relationships with HIV infection and HIV disease. Available epidemiological data regarding interactions between helminths and HIV are largely observational; results are variable and generally inconclusive. Well designed, controlled intervention studies are required to provide definitive information on the species-specific nature of these interactions and on the advantages, disadvantages and optimal timing of de-worming in relation to HIV infection.

Structural violence and clinical medicine

Structural violence refers to the social structures that put people in harm's way. Farmer and colleagues describe the impact of social violence upon people living with HIV in the US and Rwanda.

Postmortem findings and opportunistic infections in HIV-positive patients from a public hospital in Peru

There is a paucity of HIV autopsy data from South America and none that document the postmortem findings in patients with HIV/AIDS in Peru. The purpose of this autopsy study was to determine the spectrum of opportunistic infections and the causes of mortality in HIV-positive patients at a public hospital in Lima. Clinico-epidemiological information regarding HIV infection in Peru is also reviewed. Sixteen HIV-related hospital postmortems, performed between 1999 and 2004, were included in this retrospective analysis. The primary cause of death was established in 12 patients: one died of neoplasia and 11 of infectious diseases, including 3 from pulmonary infection, 7 from disseminated infection, and 2 from central nervous system infection (one case had dual pathology). Opportunistic infections were identified in 14 cases, comprising cytomegalovirus, histoplasmosis, cryptococcosis, toxoplasmosis, Pneumocystis pneumonia, aspergillosis, tuberculosis, varicella zoster virus, and cryptosporidiosis. Fourteen patients had at least one AIDS-related disease that had been neither clinically suspected nor diagnosed premortem. Moreover, 82% of the diagnoses considered to be of important clinical significance had not been suspected antemortem. The spectrum and frequency of certain opportunistic infections differed from other South American autopsy studies, highlighting the importance of performing HIV/AIDS postmortems in resource-limited countries where locally specific disease patterns may be observed.

Undiagnosed tuberculosis in a community with high HIV prevalence: implications for tuberculosis control

BACKGROUND

Although failure of tuberculosis (TB) control in sub-Saharan Africa is attributed to the HIV epidemic, it is unclear why the directly observed therapy short-course (DOTS) strategy is insufficient in this setting. We conducted a cross-sectional survey of pulmonary TB (PTB) and HIV infection in a community of 13,000 with high HIV prevalence and high TB notification rate and a well-functioning DOTS TB control program.

METHODS

Active case finding for PTB was performed in 762 adults using sputum microscopy and Mycobacterium tuberculosis culture, testing for HIV, and a symptom and risk factor questionnaire. Survey findings were correlated with notification data extracted from the TB treatment register.

RESULTS

Of those surveyed, 174 (23%) tested HIV positive, 11 (7 HIV positive) were receiving TB therapy, 6 (5 HIV positive) had previously undiagnosed smear-positive PTB, and 6 (4 HIV positive) had smear-negative/culture-positive PTB. Symptoms were not a useful screen for PTB. Among HIV-positive and -negative individuals, prevalence of notified smear-positive PTB was 1,563/100,000 and 352/100,000, undiagnosed smear-positive PTB prevalence was 2,837/100,000 and 175/100,000, and case-finding proportions were 37 and 67%, respectively. Estimated duration of infectiousness was similar for HIV-positive and HIV-negative individuals. However, 87% of total person-years of undiagnosed smear-positive TB in the community were among HIV-infected individuals.

CONCLUSIONS

PTB was identified in 9% of HIV-infected individuals, with 5% being previously undiagnosed. Lack of symptoms suggestive of PTB may contribute to low case-finding rates. DOTS strategy based on passive case finding should be supplemented by active case finding targeting HIV-infected individuals.

Increased adverse drug reactions to antimicrobials and anticonvulsants in patients with HIV infection

OBJECTIVE

To review the incidence, signs, symptoms, and mechanisms of adverse drug reactions (ADRs) to sulfonamides, anticonvulsants, and antimycobacterial medications among people with HIV.

DATA SOURCES

Searches of MEDLINE/PubMed (1980-November 2005) and National Library of Medicine Meeting Abstracts (1989-November 2005), as well as hand searches of journals and abstracts, were conducted to identify primary literature. Reference lists were reviewed to identify additional relevant reports.

STUDY SELECTION AND DATA EXTRACTION

Relevant articles and abstracts, particularly of in vitro experiments and clinical studies, were compiled and reviewed.

DATA SYNTHESIS

ADRs, especially in HIV-infected patients, are a cause for concern. Sulfonamides, anticonvulsants, and antimycobacterial drugs are commonly used to prevent and treat complications of HIV, including seizures and opportunistic infections. Patients with HIV have a much greater rate of ADRs to these drug classes, including severe and life-threatening hypersensitivity reactions. Several mechanisms of these ADRs have been postulated. Sulfamethoxazole and anticonvulsant hypersensitivity may involve the increased formation and decreased detoxification of reactive metabolites. The mechanisms for the marked increase in hypersensitivity ADRs to antimycobacterial drugs may be related to an altered immune profile in patients infected with both tuberculosis and HIV.

CONCLUSIONS

ADRs to antimicrobial and anticonvulsant therapy cause markedly increased morbidity and mortality in HIV-positive patients. Further research involving the interaction between HIV and the increased ADRs to these drugs is required.

Towards universal access to HIV prevention, treatment, care, and support: the role of tuberculosis/HIV collaboration

Tuberculosis is the oldest of the world's current pandemics and causes 8.9 million new cases and 1.7 million deaths annually. The disease is among the most common causes of morbidity and mortality in people living with HIV. However, tuberculosis is more than just part of the global HIV problem; well-resourced tuberculosis programmes are an important part of the solution to scaling-up towards universal access to comprehensive HIV prevention, diagnosis, care, and support. This article reviews the impact of the interactions between tuberculosis and HIV in resource-limited settings; outlines the recommended programmatic and clinical responses to the dual epidemics, highlighting the role of tuberculosis/HIV collaboration in increasing access to prevention, diagnostic, and treatment services; and reviews progress in the global response to the epidemic of HIV-related tuberculosis.

Management of toxoplasmic encephalitis in HIV-infected adults (with an emphasis on resource-poor settings)

BACKGROUND

Cerebral toxoplasmosis or toxoplasmic meningoencephalitis (hereafter referred to as TE) was one of the first opportunistic infections to be described in human immunodeficiency virus (HIV) -infected patients. Treatment of TE has been relatively successful in comparison to other opportunistic infections. Prior to the introduction of highly active antiretroviral therapy (HAART), a median survival of over a year was reported for patients who could tolerate the toxicity of TE treatment. HAART is becoming increasingly widely available in sub-Saharan Africa, where the majority of HIV-infected patients live. Many patients in Africa are diagnosed with HIV only after developing opportunistic infections such as TE. Hence, the optimal management of opportunistic infections such as TE is important if the benefits of subsequently initiating HAART are to be seen.

OBJECTIVES

The purpose of this review is to determine the most effective therapy for TE in HIV-infected adults. Different treatment regimens have been compared with regard to clinical and radiological response, mortality, morbidity, and serious adverse events.

SEARCH STRATEGY

A comprehensive search of relevant databases and other sources was conducted to identify relevant studies.

SELECTION CRITERIA

Randomised double-blinded trials were included.

DATA COLLECTION AND ANALYSIS

Data were extracted using standardised forms and analysed using Rev Man 4.2.7 software.

MAIN RESULTS

Three trials were found to meet the inclusion criteria. Dannemann et al 1992 and Katlama et al 1996 compared pyrimethamine plus sulfadiazine (P+S) with pyrimethamine plus clindamycin (P+C). Torre 1998 compared P+S with trimethoprim-sulfamethoxazole (TMP-SMX). For the purposes of this review, clinical outcomes were analysed as complete or partial resolution vs. failure. Patients who crossed over or were lost to follow-up were analysed as failures. Dannemann et al 1992 assessed 59 patients. Five of 26 (19%) patients randomised to P+C died in the first 6 weeks compared with 2 of the 33 (6%) patients randomised to P+S (relative risk (RR) 3.17; 95% CI 0.67-15.06). Complete or partial clinical response was obtained in 12 (46.2%) patients receiving P+C vs. 16 (48.5 %) patients receiving P+S (RR 0.95; 95% CI 0.55-1.64). Katlama et al 1996 assessed 299 patients. Twenty-nine (19%) of the 152 patients randomised to P+C died compared with 22 (15%) of the 147 patients randomised to P+S (RR 1.27; 95% CI 0.77-2.11). We were unable to obtain data on the outcomes of patients who crossed over and therefore excluded these data from the analysis. Dannemann et al 1992 and Katlama et al 1996 were analysed together for the outcome of death. The two treatment arms did not differ for death (RR 1.41; 95% CI 0.88-2.28). Torre et al 1998 assessed 77 patients. There were no deaths during the study period. Twenty-eight (70%) of 40 patients randomised to TMP-SMX had a complete or partial clinical response compared with 26 (70%) of 37 patients randomised to P+S (RR 1.0; 95% CI 0.74-1.33).

AUTHORS' CONCLUSIONS

The available evidence fails to identify any one superior regimen for the treatment of TE. The choice of therapy will often be directed by available therapy. Given the current evidence, TMP-SMX appears to be an effective alternative therapy for TE in resource-poor settings where P+S are not available.

Interactions between HIV infection and leprosy: a paradox

Early in the HIV epidemic it was feared that the disease would undermine leprosy control, as has occurred with tuberculosis. It was predicted that patients with leprosy and HIV coinfection would have an increased risk of lepromatous disease and a faster clinical evolution, and that the leprosy would be more difficult to treat. None of these concerns have materialised and the interaction between HIV and Mycobacterium leprae seems to be far more subtle than that between HIV and tuberculosis. We review the epidemiological, clinical, and pathological data relating to leprosy/HIV coinfection. The published epidemiological data are limited in quality but show neither an increased HIV prevalence among leprosy cases nor an alteration in clinical spectrum of leprosy among coinfected patients. Some data suggest that immune-mediated reactions that complicate leprosy occur at a higher frequency in coinfected patients. Leprosy has now been reported presenting as immune reconstitution disease among patients commencing highly active antiretroviral treatment. Histopathological observations reveal a normal spectrum of appearances in biopsies of leprosy lesions from coinfected patients, even among those with advanced immunodeficiency. These observations suggest that cell-mediated immune responses to M leprae are preserved at the site of disease despite evidence that these responses are abrogated systemically, by contrast with tuberculosis, in which the host granulomatous response is impaired by HIV coinfection. We speculate that this paradox may relate to differences between the activation state and rates of cell turnover within leprosy and tuberculosis granulomas that differentially affect the susceptibility of the granulomas to HIV. The interactions between leprosy and HIV have been little studied and further research on the clinical, pathological, and management aspects of this coinfection is warranted.

HIV type 2 demyelinating encephalomyelitis

A human immunodeficiency virus (HIV) type 2 (HIV-2)-infected African patient developed inflammatory demyelinating lesions of the optic nerves, spinal cord, and brain, which coincided with a decreasing CD4 cell count and with active HIV-2 replication. This case provides evidence that HIV-2 is neurotropic, extends the range of known HIV-2-associated neurological complications, and confirms the overlap between the neurological complications of HIV type 1 and HIV-2 infection.

Nonantiretroviral drug consumption by CD4 cell count in HIV-infected adults: a 5-year cohort study in Côte d'Ivoire

We followed a cohort of 592 HIV-infected adults during 1292 person-years in Abidjan before the highly active antiretroviral therapy (HAART) era. On the basis of the exhaustive monitoring of nonantiretroviral drugs actually delivered to the patients and of the real cost of drugs at the cohort center's pharmacy during the study period, we estimated the mean cost of drugs per person per year (MCPPY) overall, by drug characteristics, and by patients' baseline CD4 cell count. The MCPPY was dollar 198 US overall and dolalr 83 US, dollar 101 US, dollar 186 US, dollar 233 US, and dollar 459 US in patients with a baseline CD4 count > or = 500 cells/mm, 350 to 499 cells/mm, 200 to 349 cells/mm, 100 to 199 cells/mm, and <100 cells/mm, respectively. The most costly classes of drugs were the antibacterial (MCPPY dollar 30 US), the antifungal (dollar 16 US), and the analgesic (dollar 6 US) classes in patients with a baseline CD4 count > or = 500 cells/mm versus the antifungal (dollar 208 US), the antibacterial (dollar 49 US), and the antiparasitic (dollar 31 US) classes in patients with a baseline CD4 count <100 cells/mm. These data could be used in further cost-effectiveness analyses that seek to prioritize health interventions. Meanwhile, they roughly suggest that successful antiretroviral treatment, which would stabilize the CD4 count above 500 cells/mm, could reduce by 5-fold the cost of nonantiretroviral drugs in HIV-infected adults in Abidjan.

Tuberculosis in sub-Saharan Africa: opportunities, challenges, and change in the era of antiretroviral treatment

Rapid scale-up of antiretroviral treatment programmes is happening in Africa, driven by international advocacy and policy directives and supported by unprecedented donor funding and technical assistance. This welcome development offers hope to millions of HIV-infected Africans, among whom tuberculosis is the major cause of serious illness and death. Little in the way of HIV diagnosis or care was previously offered to patients with tuberculosis, by either national tuberculosis or AIDS control programmes, with tuberculosis services focused exclusively on diagnosis and treatment of rising numbers of patients. Tuberculosis control in Africa has yet to adapt to the new climate of antiretroviral availability. Many barriers exist, from drug interactions to historic differences in the way that tuberculosis and HIV are perceived, but failure to successfully integrate HIV and tuberculosis control will threaten the viability of both programmes. Here, we review tuberculosis epidemiology in Africa and policy implications of HIV/AIDS treatment scale-up.

Seroprevalence of Toxoplasma gondii in captive felids in Thailand

The prevalence of antibodies against Toxoplasma gondii was investigated by commercial latex agglutination test kit (Toxocheck-MT 'Eiken') in captive felids maintained at zoos and a wildlife breeding center in different geographic regions of Thailand. Sera from a total of 136 captive felids of 12 species was obtained between 2002 and 2004. The overall seroprevalence of T. gondii was found in 21 of 136 (15.4%) felids. The titers varied from 1:64 (eight samples) to 1:8192 (one sample). The seroprevalence in different geographic regions were from 0% in the northern area to 23% in the southern area. This study suggested a widespread exposure of captive felids to T. gondii in Thailand and this is the first report of serologic analysis for T. gondii in captive felids in Southeast Asia.

Early mortality among adults accessing a community-based antiretroviral service in South Africa: implications for programme design

OBJECTIVES

To determine rates, risk factors and causes of death among patients accessing a community-based antiretroviral treatment (ART) programme both prior to and following initiation of treatment.

METHODS

All in-programme deaths were ascertained between September 2002 and March 2005 among treatment-naive patients enrolled into a prospective community-based ART cohort in Cape Town, South Africa.

RESULTS

Of 712 patients (median CD4 cell count, 94 cells/microl), 578 (81%) started triple ART a median of 29 days after enrollment. 68 (9.5%) patients died during 563 person-years of observation. The high pretreatment mortality rate of 35.6 deaths/100 person-years [95% confidence interval (CI), 23.0-55.1) decreased to 2.5/100 person-years (95% CI, 0.9-6.6) at 1 year among those who received ART. However, within the first 90 days from enrollment, 29 of 44 (66%) deaths occurred among patients awaiting ART; these would not be identified by an on-treatment analysis. Multivariate analysis showed that risk of death (both pre-treatment and on-treatment) was independently associated with baseline CD4 cell count and World Health Organization (WHO) clinical stage; stage 4 disease was the strongest risk factor. Major attributed causes of death were wasting syndrome, tuberculosis, acute bacterial infections, malignancy and immune reconstitution disease.

CONCLUSIONS

Most early in-programme deaths occurred among patients with advanced immunodeficiency but who had not yet started ART. Programme evaluation using on-treatment analyses greatly underestimated early mortality. This mortality would be reduced by minimizing unnecessary in-programme delays in treatment initiation and by starting ART before development of WHO stage 4 disease.

Diagnosed tuberculosis during the follow-up of a cohort of human immunodeficiency virus-infected children in Abidjan, Côte d'Ivoire: ANRS 1278 study

INTRODUCTION

Most data on tuberculosis in human immunodeficiency virus (HIV)-infected children in Africa come from hospital-based and cross-sectional studies.

OBJECTIVES

To estimate the incidence of tuberculosis in HIV-infected children participating in an observational cohort.

METHODS

HIV-infected children in Abidjan, Côte d'Ivoire, are followed in a prospective cohort. At enrollment, all children had a physical examination, CD4 lymphocyte counts, chest radiograph and a tuberculin test. Quarterly follow-up visits are organized. All patients with suspected tuberculosis undergo specific investigations including gastric aspiration and culture. All isolates are tested for susceptibility.

RESULTS

From October 2000 to December 2003, 129 girls and 153 boys were recruited. Of children without a current or previous diagnosis of tuberculosis, 6.5% (13 of 199) had a tuberculin test result of >5 mm, compared with 17.5% of children (10 of 57) with current or previous tuberculosis (P < 0.02). Forty-eight children (17%) had a history of treated tuberculosis, and 27 children were being treated for tuberculosis at enrollment or during the first month of follow-up. Eleven children were diagnosed with tuberculosis after the first month of follow-up, and the diagnosis of mycobacterial infection was confirmed in 7 cases. Of 5 tested isolates of Mycobacterium tuberculosis, 3 were resistant to at least 1 antitubercular drug. Cumulative incidence of tuberculosis was 2060/100,000 at 12 months, 3390/100,000 at 2 years and 5930/100,000 at 3 years. The 3-year risk was 12,400/100,000 in immunocompromised children (CD4 <15%) and 3300/100,000 in other children (P < 0.0001).

CONCLUSION

The risk of tuberculosis among HIV-infected children in Côte d'Ivoire is strongly associated with the degree of immunodeficiency in HIV infection.

Efficacy and safety of two dosages of cotrimoxazole as preventive treatment for HIV-infected Malawian adults with new smear-positive tuberculosis

OBJECTIVE

To assess the efficacy and safety of two different dosages of cotrimoxazole (CTX) in prophylaxis in HIV-positive new smear-positive pulmonary tuberculosis (TB) patients in Blantyre, Malawi.

METHOD

Randomized, double-blind trial using 480 and 960 mg of CTX given to new TB patients, who were followed up until the end of the tuberculosis treatment. The primary outcome was survival. The outcome in the two groups was also compared with an unselected cohort of similar patients registered in Zomba, Malawi in 1995 and new smear-positive patients registered in the National Tuberculosis Programme in 1999. The secondary outcome was the occurrence of (opportunistic) events, especially bacterial pneumonia.

RESULTS

There were no statistically significant differences in mortality and bacterial pneumonia between the groups receiving the two different dosages. The case fatality rate at the end of the tuberculosis treatment was 15.4% in the 480 mg group and 14.0% in the 960 mg group. This was lower than the case fatality rate in the Zomba cohort (19.2%, P = 0.10) and lower than the case fatality rate in the national programme (21.0%, P < 0.001). CTX was well tolerated. Compliance was fair.

CONCLUSIONS

CTX prophylaxis may have a beneficial effect on mortality and morbidity in HIV-infected smear-positive tuberculosis patients in Malawi. The efficacy of both dosages is not significantly different. The intervention is cheap and easy to implement. These results would support implementation of CTX in this patient group until better strategies are available or evidence is convincingly presented to suggest that its benefit is marginal.

Neuropathology of human immunodeficiency virus infection: a forensic autopsy study in Dar Es Salaam, Tanzania

The objective of this study was to examine the neuropathological changes in the brain of patients infected with human immunodeficiency virus (HIV) in the Tanzanian capital Dar Es Salaam, and investigate whether the prevalence of different forms of HIV-related neuropathology varies from other countries. The subjects were patients with risk factors for HIV infection in whom forensic autopsies were performed between 1997 and 1999. In Dar Es Salaam, forensic autopsy constitutes more than 90% of all autopsies, because hospital autopsy is limited due to socio-cultural and religious reasons. HIV infection was identified in 52 of 143 patients selected from forensic autopsies. Neuropathological findings were observed in 31 of 52 HIV-infected patients; these include lymphocytic meningitis 19, bacterial meningitis 3, tuberculous brain abscess 3, cryptococcal meningitis 3, basal ganglia calcification 3, and toxoplasma encephalitis 1. HIV encephalitis, lymphoma, and cytomegalovirus encephalitis could not be found in this study. Whereas the findings should be interpreted cautiously because of possible autopsy bias and a low percentage of cases examined compared to the total number of HIV-infected patients in Tanzania, our observations provide information on the likely diagnostic possibilities to be considered in the evaluation and management of HIV-infected patients with neurological symptoms in Tanzania. In the face of decreased hospital autopsy, most studies have focused mainly on the end-stage HIV disease; forensic autopsy is a potential source of materials for studies on HIV disease spectrum at different stages.

Treatable factors associated with severe anaemia in adults admitted to medical wards in Blantyre, Malawi, an area of high HIV seroprevalence

Severe anaemia is a common presentation in non-pregnant adults admitted to hospital in southern Africa. Standard syndromic treatment based on data from the pre-HIV era is for iron deficiency, worms and malaria. We prospectively investigated 105 adults admitted consecutively to medical wards with haemoglobin < 7 g/dl. Those with acute blood loss were excluded. Patients were investigated for possible parasitic, bacterial, mycobacterial and nutritional causes of anaemia, including bone marrow aspiration, to identify potentially treatable causes. Seventy-nine per cent of patients were HIV-positive. One-third of patients had tuberculosis, which was diagnosed only by bone marrow culture in 8% of HIV-positive patients. In 21% of individuals bacteria were cultured, with non-typhi salmonella predominating and Streptococcus pneumoniae rare. Iron deficiency, hookworm infection and malaria were not common in HIV-positive anaemic adults, although heavy hookworm infections were found in 6 (27%) of the 22 HIV-negative anaemic adults. In conclusion, conventional treatment for severe anaemia in adults is not appropriate in an area of high HIV prevalence. Occult mycobacterial disease and bacteraemia are common, but iron deficiency is not common in HIV-positive patients. In addition to iron supplements, management of severe anaemia should include investigation for tuberculosis, and consideration of antibiotics active against enterobacteria.

Antiretroviral therapy in resource-poor countries: illusions and realities

The prospects for antiretroviral therapy in resource-poor settings have changed recently and considerably with the availability of generic drugs, the drastic price reduction of brand-name drugs, and the simplification of treatment. However, such cost reductions, although allowing the implementation of large-scale donor programs, have yet to render treatment accessible and possible in the general population. Successfully providing HIV treatment in high-prevalence/high-caseload countries may require that we redefine the problem as a public health mass therapy program rather than a multiplication of clinical situations. The public health goal cannot simply be the reduction of morbidity and mortality for those treated but must be the reduction in morbidity and mortality for the many, that is, at a population level.

Chronic cough in primary health care attendees, Harare, Zimbabwe: diagnosis and impact of HIV infection

BACKGROUND

Cough lasting for > or = 3 weeks (i.e., chronic cough) indicates that a patient has suspected tuberculosis (TB). At the primary health care level, the spectrum of disease that causes chronic cough has not been previously investigated in a setting with a high prevalence of human immunodeficiency virus (HIV) infection.

METHODS

A total of 544 adults with chronic cough were recruited systematically from 2 primary health care clinics, and they were evaluated using preset first- and second-line investigations and diagnostic case definitions.

RESULTS

The overall prevalence of HIV infection among the study cohort was 83%. TB was the most common diagnosis, with 207 HIV-positive patients (46%) and 27 HIV-negative patients (30%) having confirmed or probable TB. Of these, 145 HIV-positive patients with TB (70%) and 20 HIV-negative patients with TB (74%) had smear-positive cases of TB. Only 17 HIV-positive and 2 HIV-negative patients had smear-negative but culture-positive cases of TB. Lower respiratory tract infections (n = 178; HIV prevalence, 79%) and pneumonia (n = 87; HIV prevalence, 89%) were the next most common diagnoses. Asthma (n = 26; HIV prevalence, 46%), posttuberculous disease and other fibrotic lung disease (n = 34; HIV prevalence, 88%), and cardiac disease (n = 15; HIV prevalence, 93%) were more common than were Pneumocystis jiroveci pneumonia and cryptococcosis (n = 8 and n = 5, respectively; HIV prevalence, 100%), and we found no cases of nocardiosis or histoplasmosis.

CONCLUSIONS

TB was diagnosed for 43% of patients who presented with chronic cough to primary health care clinics in Harare, with 71% having smear-positive disease. The findings of TB culture added relatively little to the findings of fluorescent microscopy of concentrated sputum specimens. The prevalence of HIV infection was high across a range of diagnoses, suggesting that an HIV test should be recommended in the initial investigation of chronic cough.

Risk factors for active tuberculosis after antiretroviral treatment initiation in Abidjan

RATIONALE

In sub-Saharan Africa: (1) tuberculosis is the first cause of HIV-related mortality; (2) the incidence of tuberculosis in adults receiving highly active antiretroviral therapy (HAART) is lower than in untreated HIV-infected adults but higher than in HIV-negative adults; and (3) factors associated with the occurrence of tuberculosis in patients receiving HAART have never been described.

OBJECTIVE

To look for the risk factors for active tuberculosis in HIV-infected adults receiving HAART in Abidjan.

METHODS

Seven-year prospective cohort of HIV-infected adults, with standardized procedures for documenting morbidity. We analyzed the incidence of active tuberculosis in patients who started HAART and the association between the occurrence of tuberculosis and the characteristics of these patients at HAART initiation.

MAIN RESULTS

A total of 129 adults (median baseline CD4 count 125/mm(3)) started HAART and were then followed for 270 person-years (P-Y). At HAART initiation, 31 had a history of tuberculosis and none had current active tuberculosis. During follow-up, the incidence of active tuberculosis was 4.8/100 P-Y (95% confidence interval [CI], 2.5-8.3) overall, 3.0/100 P-Y (95% CI, 1.1-6.6) in patients with no tuberculosis history, and 11.3/100 P-Y (95% CI, 4.1-24.5) in patients with a history of tuberculosis (adjusted hazard ratio, 4.64; 95% CI, 1.29-16.62, p = 0.02).

CONCLUSION

The risk of tuberculosis after HAART initiation was significantly higher in patients with a history of tuberculosis than in those with no tuberculosis history. If confirmed by others, this finding could lead to assessment of new patterns of time-limited tuberculosis secondary chemoprophylaxis during the period of initiation of HAART in sub-Saharan African adults.

Human immunodeficiency virus type 1 genetic diversity in the nervous system: evolutionary epiphenomenon or disease determinant?

Over the past decade there has been a revolution in the understanding and care of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS)-associated disease. Much of this progress stems from a broader recognition of the importance of differences in viral types, including receptor preference(s), replication properties, and reservoirs, as contributing factors to immunosuppresion and disease progression. In contrast, there is limited conceptualizatin of viral diversity and turnover in the brain and circulation in relation to neurocognitive impairments. Herein, the authors review current concepts regarding viral molecular diversity and phenotypes together with features of HIV-1 neuroinvasion, neurotropism, neurovirulence and neurosusceptiblity. Viral genetic and antigenic diversity is reduced within the brain compared to blood or other systemic organs within individuals. Conversely, viral molecular heterogeneity is greater in patients with HIV-associated dementia compared to nondemented patients, depending on the viral gene examined. Individual viral proteins exert multiple neuropathogenic effects, although the neurological consequences of different viral polymorphisms remain uncertain. Nonetheless, host genetic polymorphisms clearly influence neurological disease outcomes and likely dictate both acquired and innate immune responses, which in turn shape viral evolution within the host. Emerging issues include widespread antiretroviral therapy resistance and increasing awareness of viral superinfections together with viral recombination, all of which are likely to impact on both HIV genetic variation and neuropathogenesis. With the persisting prevalence of HIV-induced neurocognitive disabilities, despite marked improvements in managing immunosuppression, it remains imperative to fully define and understand the mechanisms by which viral dynamics and diversity contribute to neurological disease, permitting the development of new therapeutic strategies.

Cognitive and motor deficits associated with HIV-2(287) infection in infant pigtailed macaques: a nonhuman primate model of pediatric neuro-AIDS

Lentivirus-infected nonhuman primates exhibit behavioral and neurological pathology similar to human immunodeficiency virus (HIV)-infected humans and offer a means to examine the effects of lentivirus infection while controlling for confounding factors inherent in human populations. The purpose of this study was to examine cognitive and motor development in infant macaques vertically infected with HIV-2287. Subjects were 20 infant pigtail macaques (Macaca nemestrina); 8 controls born to uninfected dams, and 12 infants whose dams had been inoculated and infected with HIV-2287 in the third trimester of pregnancy. Eight of these pregnancies had undergone surgical procedures in the form of maternal amniotic catheters or maternal amniotic and fetal carotid artery and jugular vein catheters. Data indicated that catheterization had little or no impact on behavioral development. Seven infants were vertically infected (as measured by polymerase chain reaction (PCR) at birth) and five were not infected (as measured by PCR and coculture on repeated testing). Infected infants attained cognitive and motor milestones at significantly later ages than controls. Uninfected infants, born to infected dams, attained developmental milestones at later ages than controls on all tasks, but this reached statistical significance only for the Fine Motor Task. Attainment of milestones was not correlated with viral dose, maternal CD4+ levels at parturition or infant viral RNA levels at birth. Attainment of milestones was negatively correlated with infants' proportions of CD4+ lymphocytes at birth and significantly correlated with proportions of CD4+ lymphocytes 2 weeks after birth, indicating poorer performance in those infants with a more rapid CD4+ depletion. These cognitive and motor deficits closely resemble those observed in human infants and children infected with HIV and indicate that HIV-2287-infected infant macaques represent an excellent model of pediatric neuro-acquired immunodeficiency syndrome (neuroAIDS).

Identifying deaths from AIDS in South Africa

OBJECTIVE

To quantify the HIV/AIDS deaths misclassified to AIDS-related conditions in South Africa.

DESIGN

Retrospective analysis of vital registration data.

METHODS

Cause-specific death rates for 1996 and 2000-2001 were calculated using vital registration cause-of-death profiles applied to a model (ASSA2000) estimate of total mortality rates by age and sex. The difference in the age-specific death rates for these two periods was examined to identify conditions where there was a noticeable increase in mortality following the same age pattern as the HIV deaths, thus likely to be misclassified AIDS deaths.

RESULTS

The increase in the age-specific death rates for HIV-related deaths showed a distinct age pattern, which has been observed elsewhere. Out of the 22 potential causes of death investigated, there were nine that increased in the same distinct age pattern (tuberculosis, pneumonia, diarrhoea, meningitis, other respiratory disease, non-infective gastroenteritis, other infectious and parasitic diseases, deficiency anaemias and protein energy malnutrition) and could be considered AIDS-related conditions. The increase in these conditions accounted for 61% of the total deaths related to HIV/AIDS. When added to the deaths classified as HIV-related on the death certificate, the total accounts for 93% of the ASSA2000 model estimates of the number of AIDS deaths in 2000.

CONCLUSION

As a large proportion of AIDS deaths appear to be classified to AIDS-related conditions, without reference to HIV, interpretation of death statistics in South Africa cannot be made on face value as a large proportion of deaths caused by HIV infection are misclassified.

Infection rates with Leishmania donovani and Mycobacterium tuberculosis in a village in eastern Sudan

BACKGROUND

Leishmania-tuberculosis co-infection is not uncommon in clinical practice in East Africa, but little is known about the epidemiology of this problem at population level. A cross-sectional household survey was carried out in an active visceral leishmaniasis (VL) focus in Eastern Sudan in February 2002.

METHODS

All inhabitants of Marbata village in Atbara River Area, Gedarif State, who gave informed consent, underwent both a leishmanin skin test (LST) and a tuberculin test for infection with L. donovani and Mycobacterium tuberculosis. All subjects were clinically screened for VL and tuberculosis (TB).

RESULTS

About 66% (252 of 382) were LST-positive, 26% (100 of 382) were tuberculin-positive and 20% (77 of 382) were positive for both tests. By the age of 15, more than 60% of inhabitants were LST-positive, but <20% were tuberculin-positive. By the age of 30, these percentages increased to 100 and 50%. No association was found at the individual level between leishmanial and tuberculous infection after controlling for age.

CONCLUSION

In this community study, we found no association between the risk of infection with L. donovani and M. tuberculosis. However, the progression to active VL disease might be different in M. tuberculosis-infected than in non-infected persons and vice versa. Prospective studies are needed to document the prognosis of TB/VL co-infection.

Seroprevalence of Toxoplasma gondii infection in domestic goats in Satun Province, Thailand

Goats are important domestic animals in the south of Thailand due to the minimal cost of rearing and maintaining them, and their production of both meat and milk. Toxoplasmosis is one of the most threatening parasitic zoonoses and the causative agent Toxoplasma gondii uses a wide range of warm-blooded intermediate hosts including the goat. The objective of this study was to assess the seroprevalence of antibodies to T. gondii in goats of Satun Province in Thailand. A total of 631 goat sera were examined for antibodies against toxoplasmosis with commercial latex agglutination test kits (Toxocheck-MT 'Eiken'). Of these, 176 (27.9%) were found to be positive to T. gondii; antibody titers ranged from 1:64 to 1:4096 (1:64 cut-off). Female goats were 1.73 times more likely than male to be seropositive (odds ratio [OR]=1.73; 95% confidential interval [CI]=1.11, 2.73). Dairy goats were more likely to be seropositive than meat goats (OR=1.36; 95% CI=0.84, 2.20). Goats were infected with T. gondii with acquisition of age because older goats were more likely to be seropositive than young goats under 1-year-old (for 1-2 years, OR=19.6; 95% CI=0.92, 4.15, for >2 years, OR=2.70; 95% CI=1.26, 5.80). The high seroprevalence of T. gondii antibodies found in the present study suggested widespread exposure of goats in Satun Province to T. gondii.

T-cell depletion and immunity to malaria in HIV-infections

Although early reports on HIV and malaria in co-infected subjects indicated little apparent interaction between the two infections, more recent investigations have found evidence for HIV increasing the risk from malaria. Conversely, increased viral load in susceptible cells occurs in malaria-infected people. However, the overall pattern of results is still somewhat confusing and contradictory. While morbidity from malaria may be greater in HIV-positive patients and in several reports the mortality risk is also higher, major increases in blood-stage parasitaemias that one might expect are not generally observed. The results of surveys are summarized and discussed in the context of what is known of malaria and HIV immunology in the light of recent data from humans as well as animal models.

Incidence of tuberculosis and survival after its diagnosis in patients infected with HIV-1 and HIV-2

BACKGROUND

In sub-Saharan Africa, tuberculosis (TB) is the most frequently diagnosed opportunistic infection and cause of death among HIV-infected patients. HIV-2 has been associated with less immune suppression, slower disease progression and longer survival.

OBJECTIVE

To examine whether the incidence of TB and survival after TB are associated with CD4 cell count rather than HIV type.

METHODS

Clinical and immunological data were retrospectively evaluated among an open clinic-based cohort of HIV-1- and HIV-2-infected patients to determine incidence of TB (first diagnosis > 28 days after HIV diagnosis) and subsequent mortality. Patients were grouped by CD4 cell count into those with < 200, 200-500 and > 500 x 10 cells/l.

RESULTS

Incident TB was diagnosed among 159 of 2012 patients, with 4973 person-years of observation time. In 105/159 (66.0%), the diagnosis was confirmed by direct microscopy or culture. Incidence of TB was highest in the group with < 200 x 10 cells/l (9.1/100 and 8.8/100 person-years in HIV-1 and HIV-2, respectively). Adjusted for CD4 cell count, there was no significant difference in incidence or mortality following TB between HIV-1- and HIV-2-infected patients. Mortality rate was higher in those with incident TB and HIV infection, most markedly in the group with the highest CD4 cell count (hazard ratio, 10.0; 95% confidence interval, 5.1-19.7).

CONCLUSION

Adjusted for CD4 cell count, incidence of TB was similar among HIV-1- and HIV-2-infected patients. Mortality rates after TB diagnosis were similar in both groups and high compared with those without TB.

High incidence of atypical mycobacteriosis in African HIV-infected adults with low CD4 cell counts: a 6-year cohort study in Côte d'Ivoire

The role of non-tuberculous mycobacteriosis (NTM) in HIV-related diseases in sub-Saharan Africa has long been controversial. In a 6-year cohort of 721 HIV-infected adults with systematic BACTEC blood cultures in Abidjan, Côte d'Ivoire, the incidence of NTM was 1.8/100 person-years overall and 12.2/100 person-years in patients with baseline CD4 cell counts < 100 cells/mm3. In sub-Saharan Africa, where most patients start highly active antiretroviral therapy with low CD4 cell counts, improving the diagnosis of NTM may be relevant.

A prospective study of bloodstream infections as cause of fever in Malawi: clinical predictors and implications for management

OBJECTIVE

To determine the contribution of a blood culture service to the diagnosis of fever in a resource-poor setting and to identify clinical predictors of specific bloodstream infections (BSI).

METHODS

In a descriptive, prospective study at the Medical Wards at Queen Elizabeth Central Hospital, Blantyre, Malawi, we tried to identify a specific cause of fever in febrile patients, comparing the use of routinely available diagnostic methods with the same methods plus blood culture. Clinical predictors of specific BSIs were sought.

RESULTS

A total of 352 patients admitted with fever (axillary temperature > or =37.4 degrees C) or a history of fever within the last 4 days were enrolled. Tuberculosis (TB) was the diagnosis most commonly suspected initially on clinical grounds (28%), followed by lower respiratory tract infection (16%), malaria (12%) and gastroenteritis (5%). Blood cultures were positive in 128 patients (36%); Mycobacterium tuberculosis was the most commonly isolated organism (57 patients). In most cases the diagnosis of TB had already been made using routinely available diagnostic methods, including chest radiography. In all 16 cases of Streptococcus pneumoniae bacteraemia, infection with this agent was clinically suspected, usually on the basis of pulmonary symptoms and signs. In contrast, in 30 of 65 patients (65%) with non-typhi salmonellae (NTS) bacteraemia, there were no symptoms or signs specifically suggestive of this diagnosis. Fever > or =39 degrees C and splenomegaly predicted NTS bacteraemia with an odds ratio of 8.4 (95% confidence interval 3.4-20.6, P < 0.001).

CONCLUSION

BSIs are common among patients admitted with fever. While BSI with mycobacteraemia and S. pneumoniae can usually be predicted on clinical grounds and with routinely available diagnostic methods, NTS bacteraemia often presents as a primary BSI without localizing symptoms and signs. Splenomegaly in this population indicates NTS bacteraemia rather than malaria.

Disseminated mycobacterium avium-intracellulare complex (MAC) infection in the era of effective antiretroviral therapy: is prophylaxis still indicated?

Before highly active antiretroviral therapies (HAART) were available for the treatment of persons with HIV infection, disseminated Mycobacterium avium-intracellulare complex (MAC) infection was one of the most common opportunistic infections that affected people living with AIDS. Routine use of chemoprophylaxis with a macrolide has been advocated in guidelines for the treatment of HIV-infected individuals if they have a circulating CD4+ cell count of < or =50 cells/microL. In addition, lifelong prophylaxis for disease recurrence has been recommended for those with a history of disseminated MAC infection. The introduction of HAART has resulted in a remarkable decline in the incidence of opportunistic infections and death among persons living with AIDS. Considerable reconstitution of functional immune responses against opportunistic infections can be achieved with HAART. In the case of infection with MAC, there has been a substantial reduction in the incidence of disseminated infections in the HAART era, even in countries where the use of MAC prophylaxis was never widely accepted. Moreover, the clinical picture of MAC infections in patients treated with potent antiretroviral therapies has shifted from a disseminated disease with bacteraemia to a localised infection, presenting most often with lymphadenopathy and osteomyelitis. Data from several recently conducted randomised, double-blind, placebo-controlled trials led to the current practice of discontinuing primary and secondary prophylaxis against disseminated MAC infections at stable CD4+ cell counts >100 cells/microL. These recommendations are still conservative as primary or secondary disseminated MAC infections are only rarely seen in patients who respond to HAART, despite treatment initiation at very low CD4+ cell counts. Potential adverse effects of macrolide therapy and drug interactions with antiretrovirals also metabolised via the cytochrome P450 enzyme system must be critically weighed against the marginal benefit that MAC prophylaxis may provide in addition to treatment with HAART. These authors feel that, unless patients who initiate HAART at low CD4+ cell counts do not respond to HIV-treatment, routine MAC prophylaxis should not be recommended. Nevertheless, the patient population for whom MAC prophylaxis may still be indicated in the era of HAART needs to be identified in prospectively designed clinical trials.

HIV-1/AIDS neuropathology in a Canadian teaching centre

BACKGROUND

The nervous system is a major target of HIV-1 infection and site of many complications of AIDS. Most of our knowledge pertaining to the range and frequency of neuropathology in HIV-1/AIDS is from large centres outside Canada in different social and health care settings. The goal of the present study was to describe HIV-1/AIDS-associated neuropathology before and during the era of highly active antiretroviral therapy at a Canadian teaching centre.

METHODS

The records of the Department of Pathology, London Health Sciences Centre were electronically searched for cases of HIV-1/AIDS that came to postmortem examination since 1985. The clinical records and pathological materials were reviewed.

RESULTS

Sixteen autopsies of HIV-1/AIDS were identified. All patients were male. Fourteen contracted HIV-1 through high risk homosexual activity, one through the transfusion of blood products and one through intravenous drug use. Three patients (19%) had pre-mortem evidence of HIV-1 associated dementia. At autopsy, 12 of the 16 cases had neuropathological findings and the most common diagnoses were HIV-1 encephalitis, progressive multifocal leukoencephalopathy, toxoplasmosis, and primary CNS lymphoma.

CONCLUSIONS

High risk homosexual activity was a more prominent factor in acquiring AIDS in cases coming to postmortem examination compared with previous reports from most larger urban centres outside Canada where injection drug use and high risk heterosexual activity factored prominently. The incidence of HIV-1 associated dementia was similar to that reported previously. This study confirms the heavy burden and wide spectrum of disease experienced by the nervous system in HIV-1/AIDS.

Management of HIV-associated focal brain lesions in developing countries

BACKGROUND

HIV-associated focal brain lesions (HFBL) are caused by opportunistic infections, neoplasms, or cerebrovascular diseases. In developed countries, toxoplasma encephalitis (TE) is the most frequent cause, followed by primary CNS lymphoma (PCNSL). Guidelines based on these causes however are poorly suited to developing countries, where treatable infections predominate as causes of HFBL.

AIM

To determine a practical approach to the management of HFBL in developing countries.

DESIGN

Case series.

METHODS

Patients (n = 32) were managed based on presumed aetiologies of the focal brain lesions, determined by collating information from CT scans, CSF and blood studies, concurrent non-neurological illness and response to treatment.

RESULTS

The principal presumed cause of HFBL was tuberculosis (69%). The therapeutic response was good in 69% of patients.

DISCUSSION

In developing countries, infections are the predominant cause of HFBL, the principal causes being infections that are endemic to the populations being studied. Empiric treatment based on limited investigations should be directed according to the nature of such infections. A modified algorithm is proposed.

Cerebrospinal fluid viral load, virus isolation, and intrathecal immunoactivation in HIV type 2 infection

Four patients with HIV-2 infection were followed longitudinally with cerebrospinal fluid (CSF) analyses. Two patients had positive CSF HIV-2 isolations. These two patients had CD4 cell count below 200 x 10(6)/liter and maximum CSF HIV-2 RNA viral loads above 4000 copies/ml. Intrathecal immune activation was demonstrated by elevated CSF neopterin concentrations (14-18 nmol/liter). No opportunistic infections were diagnosed. After antiretroviral treatment CSF viral counts decreased to below 125 copies/ml and CSF neopterin concentrations decreased. In two other patients who had CD4 counts within the normal range CSF virus isolations were repeatedly negative and viral CSF loads were below 125 copies/ml. However, a slightly elevated CSF neopterin concentration in one sample and pleocytosis in another might also be caused by HIV-2 in these patients. Before antiretroviral treatment HIV-2 isolations from blood were positive in all four patients. Maximum HIV-2 RNA viral loads were higher in blood than in CSF. Treatment failure in one patient with increasing viral loads in blood did not result in viral rebound in CSF.

Human immunodeficiency virus and the prevalence of undiagnosed tuberculosis in African gold miners

We hypothesized that rapid presentation may be a general feature of tuberculosis (TB) associated with human immunodeficiency virus (HIV) that limits the impact of HIV on the point prevalence of TB. To investigate this, we performed a cross-sectional HIV and TB disease survey with retrospective and prospective follow-up. HIV prevalence among 1,773 systematically recruited miners was 27%. TB incidence was much more strongly HIV associated (incidence rate ratio, 5.5; 95% confidence interval [CI], 3.5-8.6) than the point prevalence of undiagnosed TB disease (odds ratio, 1.7; 95% CI, 0.9-3.3). For smear-positive TB, 7 of 9 (78%) prevalent cases were HIV negative, and point prevalence was nonsignificantly lower in miners who were HIV positive (odds ratio, 0.8; 95% CI, 0.1-4.2). The calculated mean duration of smear positivity before diagnosis (point prevalence/incidence) was substantially shorter for HIV-positive than HIV-negative TB patients (0.17 and 1.15 years, respectively; ratio, 0.15; 95% CI, 0.00-0.73). HIV has considerably less impact on the point prevalence of TB disease than on TB incidence, probably because rapid disease progression increases presentation and case-finding rates. The difference in mean duration of smear positivity was particularly marked and, if generalizable, will have major implications for TB control prospects in high HIV prevalence areas.