Etiology of suspected pneumonia in adults admitted to a high-dependency unit in Blantyre, Malawi.

The microbiologic etiology of severe pneumonia in hospitalized patients is rarely known in sub-Saharan Africa. Through a comprehensive diagnostic work-up, we aimed to identify the causative agent in severely ill patients with a clinical picture of pneumonia admitted to a high-dependency unit. A final diagnosis was made and categorized as confirmed or probable by using predefined criteria. Fifty-one patients were recruited (45% females), with a mean age of 35 years (range = 17-88 years), of whom 11(22%) died. Forty-eight (94%) of the patients were seropositive for human immunodeficiency virus; 14 (29%) of these patients were receiving antiretroviral treatment. Final diagnoses were bacterial pneumonia (29%), Pneumocystis jirovecii pneumonia (27%), pulmonary tuberculosis (22%), and pulmonary Kaposi's sarcoma (16%); 39 (77%) of these cases were confirmed cases. Fifteen (29%) patients had multiple isolates. At least 3 of 11 viral-positive polymerase chain reaction (PCR) results of bronchoalveolar lavage fluid were attributed clinical relevance. No atypical bacterial organisms were found.

Dysregulated humoral immunity to nontyphoidal Salmonella in HIV-infected African adults.

Nontyphoidal Salmonellae are a major cause of life-threatening bacteremia among HIV-infected individuals. Although cell-mediated immunity controls intracellular infection, antibodies protect against Salmonella bacteremia. We report that high-titer antibodies specific for Salmonella lipopolysaccharide (LPS) are associated with a lack of Salmonella-killing in HIV-infected African adults. Killing was restored by genetically shortening LPS from the target Salmonella or removing LPS-specific antibodies from serum. Complement-mediated killing of Salmonella by healthy serum is shown to be induced specifically by antibodies against outer membrane proteins. This killing is lost when excess antibody against Salmonella LPS is added. Thus, our study indicates that impaired immunity against nontyphoidal Salmonella bacteremia in HIV infection results from excess inhibitory antibodies against Salmonella LPS, whereas serum killing of Salmonella is induced by antibodies against outer membrane proteins.

Nutritional status of Malawian adults on antiretroviral therapy 1 year after supplementary feeding in the first 3 months of therapy.

OBJECTIVE: To test the hypothesis that individuals on antiretroviral therapy (ART) for 3 months with a greater body mass index (BMI) as a result of supplementary feeding with ready-to-use fortified spread would maintain a higher BMI 9 months after the feeding ended. METHODS: Two cohorts of wasted adults with AIDS, after 12 months of ART and 3 months of supplementary feeding with either ready-to-use fortified spread, an energy dense lipid paste; or corn/soy blended flour, were assessed for clinical and anthropometric status, quality of life, and ART adherence after 3 and 9 months. RESULTS: 336 ART patients participated: 162 who had received ready-to-use fortified spread and 174 who had received corn/soy blended flour. 9 months after stopping food supplements, both groups had a similar BMI, fat-free body mass, hospitalization rate and mortality. Binary logistic regression modelling showed that lower BMI, lower CD4 count, and older age at baseline were associated with a higher risk of death (odds ratio for BMI = 0.63, 95% CI 0.47-0.79). Adherence to the ART regimen and quality of life were similar in both cohorts. CONCLUSION: While supplementary feeding with ready-to-use fortified spread can ameliorate the BMI, an established risk factor for mortality, this effect is sustained only during the time of the intervention. Supplementary feeding of wasted patients for longer than 3 months should be investigated.

Diagnosis of antiretroviral therapy failure in Malawi: poor performance of clinical and immunological WHO criteria.

OBJECTIVES: In antiretroviral therapy (ART) scale-up programmes in sub-Saharan Africa viral load monitoring is not recommended. We wanted to study the impact of only using clinical and immunological monitoring on the diagnosis of virological ART failure under routine circumstances. METHODS: Clinicians in two urban ART clinics in Malawi used clinical and immunological monitoring to identify adult patients for switching to second-line ART. If patients met clinical and/or immunological failure criteria of WHO guidelines and had a viral load <400 copies/ml there was misclassification of virological ART failure. RESULTS: Between January 2006 and July 2007, we identified 155 patients with WHO criteria for immunological and/or clinical failure. Virological ART failure had been misclassified in 66 (43%) patients. Misclassification was significantly higher in patients meeting clinical failure criteria (57%) than in those with immunological criteria (30%). On multivariate analysis, misclassification was associated with being on ART <2 years [OR = 7.42 (2.63, 20.95)] and CD4 > 200 cells/microl [OR = 5.03 (2.05, 12.34)]. Active tuberculosis and Kaposi's sarcoma were the most common conditions causing misclassification of virological ART failure. CONCLUSION: Misclassification of virological ART failure occurs frequently using WHO clinical and immunological criteria of ART failure for poor settings. A viral load test confirming virological ART failure is therefore advised to avoid unnecessary switching to second-line regimens.

The public health approach to identify antiretroviral therapy failure: high-level nucleoside reverse transcriptase inhibitor resistance among Malawians failing first-line antiretroviral therapy.

BACKGROUND: Over 150,000 Malawians have started antiretroviral therapy (ART), in which first-line therapy is stavudine/lamivudine/nevirapine. We evaluated drug resistance patterns among patients failing first-line ART on the basis of clinical or immunological criteria in Lilongwe and Blantyre, Malawi. METHODS: Patients meeting the definition of ART failure (new or progressive stage 4 condition, CD4 cell count decline more than 30%, CD4 cell count less than that before treatment) from January 2006 to July 2007 were evaluated. Among those with HIV RNA of more than 1000 copies/ml, genotyping was performed. For complex genotype patterns, phenotyping was performed. RESULTS: Ninety-six confirmed ART failure patients were identified. Median (interquartile range) CD4 cell count, log10 HIV-1 RNA, and duration on ART were 68 cells/microl (23-174), 4.72 copies/ml (4.26-5.16), and 36.5 months (26.6-49.8), respectively. Ninety-three percent of samples had nonnucleoside reverse transcriptase inhibitor mutations, and 81% had the M184V mutation. The most frequent pattern included M184V and nonnucleoside reverse transcriptase inhibitor mutations along with at least one thymidine analog mutation (56%). Twenty-three percent of patients acquired the K70E or K65R mutations associated with tenofovir resistance; 17% of the patients had pan-nucleoside resistance that corresponded to K65R or K70E and additional resistance mutations, most commonly the 151 complex. Emergence of the K65R and K70E mutations was associated with CD4 cell count of less than 100 cells/microl (odds ratio 6.1) and inversely with the use of zidovudine (odds ratio 0.18). Phenotypic susceptibility data indicated that the nucleoside reverse transcriptase inhibitor backbone with the highest activity for subsequent therapy was zidovudine/lamivudine/tenofovir, followed by lamivudine/tenofovir, and then abacavir/didanosine. CONCLUSION: When clinical and CD4 cell count criteria are used to monitor first-line ART failure, extensive nucleoside reverse transcriptase inhibitor and nonnucleoside reverse transcriptase inhibitor resistance emerges, with most patients having resistance profiles that markedly compromise the activity of second-line ART.

Supplementary feeding with either ready-to-use fortified spread or corn-soy blend in wasted adults starting antiretroviral therapy in Malawi: randomised, investigator blinded, controlled trial.

OBJECTIVE: To investigate the effect of two different food supplements on body mass index (BMI) in wasted Malawian adults with HIV who were starting antiretroviral therapy. DESIGN: Randomised, investigator blinded, controlled trial. SETTING: Large, public clinic associated with a referral hospital in Blantyre, Malawi. PARTICIPANTS: 491 adults with BMI <18.5. INTERVENTIONS: Ready-to-use fortified spread (n=245) or corn-soy blend (n=246). PRIMARY OUTCOMES: changes in BMI and fat-free body mass after 3.5 months. SECONDARY OUTCOMES: survival, CD4 count, HIV viral load, quality of life, and adherence to antiretroviral therapy. RESULTS: The mean BMI at enrolment was 16.5. After 14 weeks, patients receiving fortified spread had a greater increase in BMI and fat-free body mass than those receiving corn-soy blend: 2.2 (SD 1.9) v 1.7 (SD 1.6) (difference 0.5, 95% confidence interval 0.2 to 0.8), and 2.9 (SD 3.2) v 2.2 (SD 3.0) kg (difference 0.7 kg, 0.2 to 1.2 kg), respectively. The mortality rate was 27% for those receiving fortified spread and 26% for those receiving corn-soy blend. No significant differences in the CD4 count, HIV viral load, assessment of quality of life, or adherence to antiretroviral therapy were noted between the two groups. CONCLUSION: Supplementary feeding with fortified spread resulted in a greater increase in BMI and lean body mass than feeding with corn-soy blend. TRIAL REGISTRATION: Current Controlled Trials ISRCTN67515515.

Malaria treatment efficacy among people living with HIV: the role of host and parasite factors.

Identification of an effect of HIV-associated immunosuppression on response to antimalarial therapy would help guide management of malaria infection in areas of high HIV prevalence. Therefore, we conducted an observational study of people living with HIV infection in Blantyre, Malawi. Participants who developed malaria were treated with sulfadoxine-pyrimethamine (SP) and followed for 28 days. Molecular markers for SP resistance were measured. One hundred seventy-eight episodes of malaria were assessed. The 28-day cumulative treatment failure rate was 29.1%. In univariate analysis, CD4 cell count was not associated with treatment failure (hazard ratio 0.6, 95% confidence interval 0.3-1.2). Among children, the risk of treatment failure increased with infection with SP-resistant parasites and anemia. Decreased CD4 cell count was not associated with impaired response to antimalarial therapy or diminished ability to clear SP-resistant parasites, suggesting that acquired immunity to malaria is retained in the face of HIV-associated immunosuppression.

Can the initial success of the Malawi ART scale-up programme be sustained? The example of Queen Elizabeth Central Hospital, Blantyre.

The antiretroviral therapy clinic of Queen Elizabeth Central Hospital (QECH), Blantyre, Malawi was established as a fee-paying clinic in 2000. In 2004 a successful transition to free-of-charge antiretroviral therapy (ART) provision was made with the introduction of the national ART scale-up programme. Despite the human resource crisis in the healthcare system, remarkable improvements in quantity and quality of care, a reduction of defaulters, favourable ART outcomes and better access to ART for the poor, women and children were achieved. A number of challenges need to be overcome to sustain the initial success of the national ART scale-up programme in QECH, the most important being the shortage of ART staff in relation to the ever-expanding patient population.

Nevirapine-based antiretroviral therapy started early in the course of tuberculosis treatment in adult Malawians.

BACKGROUND: The tuberculosis (TB) mortality rate of registered TB patients in Malawi is 23%, and 59% of the deaths occur in the first 2 months of treatment. HIV-related complications appear to be an important cause. Starting antiretroviral therapy early during tuberculosis treatment may improve outcome but problems often arise with drug interactions, adherence, toxicity and immune reconstitution disease (IRD). METHODS: We prospectively followed 27 HIV-infected adult Malawians after starting Triomune (a generic fixed drug combination of stavudine, lamivudine and nevirapine) in the second week of tuberculosis treatment. RESULTS: At baseline, 88% had CD4+ T-cell counts <100 cells/ml, all were anaemic and 78% were malnourished. Five patients (19%) died, two withdrew consent and one stopped all drugs due to hepatitis. At 6 months, all but one of the 19 remaining patients had good virological results (16 patients: <400 copies/ml, two patients: <1,000 copies/ml) and the median CD4+ T cell increase was 170 cells/ml. Adverse events were numerous, particularly in the first 2 months. Suspected IRD episodes could be managed without treatment interruptions. During the lead-in phase, 59% of nevirapine plasma levels were sub-therapeutic despite good adherence, compared with only 14% during weeks 4 and 8. CONCLUSION: It is feasible to start Triomune early during TB treatment with good treatment outcome. The nevirapine lead-in phase should be avoided when rifampicin-based tuberculosis treatment is started >1 week beforehand.

Diagnostic accuracy and clinical utility of a simplified low cost method of counting CD4 cells with flow cytometry in Malawi: diagnostic accuracy study.

OBJECTIVES: To assess the diagnostic accuracy and clinical utility of a simplified low cost method for measuring absolute and percentage CD4 counts with flow cytometry. DESIGN: A CD4 counting method (Blantyre count) using a CD4 and CD45 antibody combination with reduced blood and reagent volumes. Diagnostic accuracy was assessed by measuring agreement of the index test with two other assays (TruCount and FACSCount). Clinical utility was investigated by comparing CD4 counts with the new assay with WHO clinical staging in patients with HIV. SETTING: Research laboratories and antiretroviral therapy clinic at a medical school and large government hospital in southern Malawi. PARTICIPANTS: Assay comparisons were performed on consecutive blood samples sent for CD4 counting from 129 patients with HIV. Comparison of CD4 count with staging was conducted on 253 consecutive new patients attending the antiretroviral therapy clinic. MAIN OUTCOME MEASURES: Limits of agreement with 95% confidence intervals between index test and reference standards. RESULTS: The limits of agreement for Blantyre count and TruCount were excellent (cell count -48.9 to 27.0 x10(9)/l for absolute counts in the CD4 range <400x10(9)/l and -2.42% to 2.37% for CD4 percentage). The assay was affordable with reagent costs per test of $0.44 ( pound0.22, euro0.33) for both absolute count and CD4 percentage, and $0.11 for CD4 percentage alone. Of 193 patients with clinical stage I or II disease, who were ineligible for antiretroviral therapy by clinical staging criteria, 73 (38%) had CD4 counts <200x10(9)/l. By contrast, 12 (20%) of 60 patients with stage III or IV disease had CD4 counts >350x10(9)/l. CONCLUSIONS: This simplified method of counting CD4 cells with flow cytometry has good agreement with established commercial assays, is affordable for routine clinical use in Africa, and could improve clinical decision making in patients with HIV.

Finger-prick blood samples can be used interchangeably with venous samples for CD4 cell counting indicating their potential for use in CD4 rapid tests.

The objective of this study was to investigate the utility of finger-prick blood samples for CD4 cell counting. We estimated agreement between CD4 cell counts in paired finger-prick and venous samples from 110 HIV-infected adults from Malawi. Bias was 6.6 cells/microl (limits of agreement -50.7 and 63.7 cells/microl) for absolute counts and 0.71% (limits of agreement -2.07 and 3.48%) for %CD4/lymphocyte suggesting that finger-prick blood samples can be used interchangeably with venous samples for CD4 cell counting.

Nevirapine concentrations in HIV-infected children treated with divided fixed-dose combination antiretroviral tablets in Malawi and Zambia.

OBJECTIVE: To investigate nevirapine concentrations in African HIV-infected children receiving divided Triomune tablets (stavudine+lamivudine+nevirapine). DESIGN: Cross-sectional study. METHODS: Steady-state plasma nevirapine concentrations were determined in Malawian and Zambian children aged 8 months to 18 years receiving Triomune in routine outpatient settings. Predictors from height-for-age, body mass index (BMI)-for-age, age, sex, post-dose sampling time and dose/m2/day were investigated using centre-stratified regression with backwards elimination (P<0.1). RESULTS: Of the 71 Malawian and 56 Zambian children (median age 8.4 vs 8.5 years, height-for-age -3.15 vs -1.84, respectively), only 1 (3%) of those prescribed > or =300 mg/m2/day nevirapine had subtherapeutic concentrations (<3 mg/l) compared with 22 (23%) of those prescribed <300 mg/m2/day; most children with subtherapeutic nevirapine concentrations were taking half or quarter Triomune tablets. Lower nevirapine concentrations were independently associated with lower height-for-age (indicating stunting) (0.37 mg/l per unit higher [95% confidence interval (CI): -0.003, +0.74]; P=0.05), lower prescribed dose/m2 (+0.89 mg/l per 50 mg/m2 higher [95% CI: 0.32, 1.46]; P=0.002) and higher BMI-for-age (indicating lack of wasting) (-0.42 mg/l per unit higher [95% CI: -0.80, -0.04]; P=0.03). CONCLUSIONS: Currently available adult fixed-dose combination tablets are not well suited to children, particularly at younger ages: Triomune 30 is preferable to Triomune 40 because of the higher dose of nevirapine relative to stavudine. Further research is required to confirm that concentrations are reduced in stunted children but increased in wasted children. Development of appropriate paediatric fixed-dose combination tablets is essential if antiretroviral therapy is to be made widely available to children in resource-limited settings.

Pneumocystis pneumonia in HIV-positive adults, Malawi.

In a prospective study of 660 HIV-positive Malawian adults, we diagnosed Pneumocystis jirovecii pneumonia (PcP) using clinical features, induced sputum for immunofluorescent staining, real-time PCR, and posttreatment follow-up. PcP incidence was highest in patients with the lowest CD4 counts, but PcP is uncommon compared with incidences of pulmonary tuberculosis and bacterial pneumonia.

Challenges in HIV post-exposure prophylaxis for occupational injuries in a large teaching hospital in Malawi.

We describe the evaluation of the HIV post-exposure prophylaxis (PEP) programme for occupational injuries in Queen Elizabeth Central Hospital, Blantyre, Malawi. An audit was performed 1 year after introduction, by reviewing files of all clients who sought advice regarding PEP. In addition, the incidence of occupational injuries and awareness of the programme were assessed through interviews with nurses. The logistics of the programme were adequate. Of 29 clients who reported occupational injuries,19 started PEP. Only double antiretroviral drug therapy was available; side-effects were common but generally mild. Attendance of scheduled follow-up visits was poor, and few HIV test results after completion of PEP were obtained. Interviews with nurses revealed a high incidence of occupational injuries, but many did not report for advice about PEP; mostly because of unawareness of the programme and a reluctance to be tested for HIV.

Observational cohort study of HIV-infected African children.

BACKGROUND: Most information about children living with HIV is based on follow up from children identified through mother-to-child transmission studies. Children identified through voluntary counseling and testing (VCT) represent a unique cohort that has not been previously described in the literature. METHODS: Children who were found to have HIV infection through VCT were offered enrollment in this study. They were evaluated monthly and encouraged to return to the clinic any time they were ill. Thorough evaluation was performed for every illness. RESULTS: Forty-five children were enrolled in the study. Many of the participants (33%) had a serious acute disease at the time of enrollment. The most common diagnoses were symptomatic malaria and pneumonia. The children were more ill than adults who were enrolled in a simultaneous study and had a higher death rate (37 versus 15 deaths per 100 person-years of observation). The mortality rate was 22%. Undernutrition and low CD4 cell count were independently associated with increased risk of death. CONCLUSIONS: Malawian children found to be HIV-infected through VCT had a high morbidity and mortality rate, highlighting the potential benefit of trimethoprim-sulfamethizole prophylaxis and available antiretroviral therapy.

Impact of HIV-associated immunosuppression on malaria infection and disease in Malawi.

BACKGROUND: Human immunodeficiency virus (HIV) infection and malaria coexist in much of Africa. Previous studies differ in their findings on the interactions between the 2 infections. METHODS: Adults living with HIV infection in Blantyre, Malawi, were enrolled in a longitudinal observational study from September 2002 to August 2004. Malaria blood smears were obtained monthly and for any illness suggestive of malaria. Complete evaluations of all illness episodes were conducted, regardless of malaria smear results. RESULTS: The incidence of clinical malaria episodes was higher in participants with CD4 cell counts <200 cells/mm3 than in those with CD4 cell counts >500 cells/mm3. The trend was preserved when increasingly specific definitions of malaria disease were used. The prevalence of malaria infection was not associated with CD4 cell count. In per-visit analysis, lower CD4 cell counts were associated with higher incidences of pneumonia, sepsis, and tuberculosis but not of malaria. Severe malaria was rare, with only 3 cases in 591 person-years of observation. Parasite density and CD4 cell count were independent risk factors for fever. CONCLUSIONS: Profoundly immunosuppressed adults with HIV infection require more-frequent treatment for uncomplicated malaria, but malaria infection and disease are less strongly associated with HIV-associated immunosuppression than are other opportunistic infections. Where malaria is common, the high incidence of fever found among immunosuppressed adults may lead to misclassification of illness episodes as malaria.

A community-based study of the incidence of trimethoprim-sulfamethoxazole-preventable infections in Malawian adults living with HIV.

The benefits of trimethoprim-sulfamethoxazole (TS) prophylaxis reported for persons living with HIV in Cote d'Ivoire are difficult to extrapolate to sub-Saharan African countries where bacterial resistance to TS is higher and cross-resistance between TS and sulfadoxine-pyrimethamine (SP) may impair SP efficacy for malaria treatment. We conducted a community-based cohort study to measure the incidence of potentially TS-preventable illnesses in Blantyre, Malawi. We found a high incidence of malaria, invasive bacterial infections, and probable bacterial pneumonias but low rates of Pneumocystis jiroveci pneumonia, isosporiasis, and Toxoplasma encephalitis. Most bacterial isolates were resistant to TS but sensitive to azithromycin, a possible alternative to TS. Clinical trials are needed to determine the role of TS or alternative regimens for prophylaxis against secondary infections among people living with HIV in sub-Saharan Africa. These should also assess benefit in patients receiving antiretroviral therapy.