Khadija Said

Assessment of the novel T-cell activation marker-tuberculosis assay for diagnosis of active tuberculosis in children: a prospective proof-of-concept study.

BACKGROUND The diagnosis of paediatric tuberculosis is complicated by non-specific symptoms, difficult specimen collection, and the paucibacillary nature of the disease. We assessed the accuracy of a novel immunodiagnostic T-cell activation marker-tuberculosis (TAM-TB) assay in a proof-of-concept study to identify children with active tuberculosis. METHODS Children with symptoms that suggested tuberculosis were prospectively recruited at the NIMR-Mbeya Medical Research Center in Mbeya, and the Ifakara Health Institute in Bagamoyo, Tanzania, between May 10, 2011, and Sept 4, 2012. Sputum and peripheral blood mononuclear cells were obtained for Mycobacterium tuberculosis culture and performance assessment of the TAM-TB assay. The children were assigned to standardised clinical case classifications based on microbiological and clinical findings. FINDINGS Among 290 children screened, we selected a subgroup of 130 to ensure testing of at least 20 with culture-confirmed tuberculosis. 17 of 130 children were excluded because of inconclusive TAM-TB assay results. The TAM-TB assay enabled detection of 15 of 18 culture-confirmed cases (sensitivity 83·3%, 95% CI 58·6-96·4). Specificity was 96·8% (95% CI 89·0-99·6) in the cases that were classified as not tuberculosis (n=63), with little effect from latent tuberculosis infection. The TAM-TB assay identified five additional patients with highly probable or probable tuberculosis, in whom M tuberculosis was not isolated. The median time to diagnosis was 19·5 days (IQR 14-45) for culture. INTERPRETATION The sputum-independent TAM-TB assay is a rapid and accurate blood test that has the potential to improve the diagnosis of active tuberculosis in children. FUNDING European and Developing Countries Clinical Trials Partnership, German Federal Ministry of Education and Research, and Swiss National Science Foundation.

Safety and Immunogenicity of H1/IC31®, an Adjuvanted TB Subunit Vaccine, in HIV-Infected Adults with CD4+ Lymphocyte Counts Greater than 350 cells/mm3: A Phase II, Multi-Centre, Double-Blind, Randomized, Placebo-Controlled Trial

Background Novel tuberculosis vaccines should be safe, immunogenic, and effective in various population groups, including HIV-infected individuals. In this phase II multi-centre, double-blind, placebo-controlled trial, the safety and immunogenicity of the novel H1/IC31 vaccine, a fusion protein of Ag85B-ESAT-6 (H1) formulated with the adjuvant IC31, was evaluated in HIV-infected adults. Methods HIV-infected adults with CD4+ T cell counts >350/mm3 and without evidence of active tuberculosis were enrolled and followed until day 182. H1/IC31 vaccine or placebo was randomly allocated in a 5∶1 ratio. The vaccine was administered intramuscularly at day 0 and 56. Safety assessment was based on medical history, clinical examinations, and blood and urine testing. Immunogenicity was determined by a short-term whole blood intracellular cytokine staining assay. Results 47 of the 48 randomised participants completed both vaccinations. In total, 459 mild or moderate and 2 severe adverse events were reported. There were three serious adverse events in two vaccinees classified as not related to the investigational product. Local injection site reactions were more common in H1/IC31 versus placebo recipients (65.0% vs. 12.5%, p = 0.015). Solicited systemic and unsolicited adverse events were similar by study arm. The baseline CD4+ T cell count and HIV viral load were similar by study arm and remained constant over time. The H1/IC31 vaccine induced a persistent Th1-immune response with predominately TNF-α and IL-2 co-expressing CD4+ T cells, as well as polyfunctional IFN-γ, TNF-α and IL-2 expressing CD4+ T cells. Conclusion H1/IC31 was well tolerated and safe in HIV-infected adults with a CD4+ Lymphocyte count greater than 350 cells/mm3. The vaccine did not have an effect on CD4+ T cell count or HIV-1 viral load. H1/IC31 induced a specific and durable Th1 immune response. Trial registration Pan African Clinical Trials Registry (PACTR) PACTR201105000289276

Pulmonary Aspergilloma: A Treatment Challenge in Sub-Saharan Africa

In April 2011, a 68-year-old man presented himself at our research clinic in rural Tanzania with a three-month persistent productive cough, chest pain, night sweats, and recurrent nonmassive haemoptysis. He denied fever, night sweats, weight loss, and any recent contact with a known tuberculosis case. A prior treatment with a broadspectrum antibiotic had not been successful. The patient reported having been treated for tuberculosis, diagnosed by sputum smear ten years ago. On examination he was afebrile, in a reduced general condition with a body mass index of 17.1 kg/m. Other findings were bilateral reduced breath sounds and mild clubbing. Testing for HIV with two rapid tests (SD Bioline HIV 1/2 3.0 and Determine HIV-1/2) was negative. Posteroanterior chest radiography in an erect position showed a cavity of 60 mm673 mm diameter in the right upper lobe containing an intracavitary focal mass of 47 mm631 mm diameter with adjacent moon-shaped radiolucency (Figure 1). A second radiography in a supine position showed a changed position of this focal mass (Figure 2). A chest x-ray of the previous TB episode was not available for comparison. Smear microscopy of early morning and spot sputum after Ziehl-Neelsen stain was negative for acid-fast bacilli. A nucleic acid amplification test (Xpert MTB/RIF) did not detect Mycobacterium tuberculosis. Both the early morning and spot sputum samples were subsequently cultured on solid (Lowenstein Jensen) and in liquid (MGIT) media, neither of which showed mycobacterial growth after eight and six weeks, respectively. In order to isolate Aspergillus, a sabouraud dextrose agar was inoculated directly with sputum, but only Enterobacter cloacae could be found. Due to lack of facilities, neither an ELISA for IgG antibodies to Aspergillus nor an Aspergillus precipitin test could be performed. Based on radiographies, a diagnosis of single pulmonary aspergilloma was established, but we could not exclude that the symptoms were caused by tuberculosis reactivation or reinfection. With negative sputum smears, chest radiography findings consistent with tuberculosis, and a lack of response to a trial broad-spectrum antimicrobial agent, our patient fulfilled the WHO criteria for sputum smear–negative tuberculosis. Without options for surgical treatment of pulmonary aspergilloma, we were now faced with the decision of either starting medication for pulmonary aspergilloma or sending the patient for tuberculosis treatment. Considering unavailability of sputum culture results at this point and our setting with high prevalence of tuberculosis, we presented the case to the National Tuberculosis and Leprosy Program (NTLP) which initiated six-month standard tuberculosis treatment according to national guidelines, which implies prescription of rifampin, isoniazid, ethambutol, and pyrazinamide for two months, followed by rifampin and isoniazid for four months. After six months of antituberculosis therapy, the patient was still in a reduced condition, complaining about productive cough and chest pain, but no haemoptysis or night sweats. His body mass index had increased to 19.2 kg/m. Radiographies, however, did not show any improvement. Because of the persistent symptomology, the patient was subsequently started on antifungal treatment with itraconazole 200 mg daily for six months. At the end of this period, the treatment was extended for another six months because the patient had reported that the dispensary had not been able to provide him with medication continuously and therefore he had not been able to take medication for the last three months of treatment. At the last follow-up in October 2012 we noticed a clinical improvement of the chest pain and no productive cough despite a follow-up radiography not showing any changes.

Prevalence and clinical relevance of helminth co-infections among tuberculosis patients in urban Tanzania

Background Helminth infections can negatively affect the immunologic host control, which may increase the risk of progression from latent Mycobacterium tuberculosis infection to tuberculosis (TB) disease and alter the clinical presentation of TB. We assessed the prevalence and determined the clinical relevance of helminth co-infection among TB patients and household contact controls in urban Tanzania. Methodology Between November 2013 and October 2015, we enrolled adult (≥18 years) sputum smear-positive TB patients and household contact controls without TB during an ongoing TB cohort study in Dar es Salaam, Tanzania. We used Baermann, FLOTAC, Kato-Katz, point-of-care circulating cathodic antigen, and urine filtration to diagnose helminth infections. Multivariable logistic regression models with and without random effects for households were used to assess for associations between helminth infection and TB. Principal findings A total of 597 TB patients and 375 household contact controls were included. The median age was 33 years and 60.2% (585/972) were men. The prevalence of any helminth infection among TB patients was 31.8% (190/597) and 25.9% (97/375) among controls. Strongyloides stercoralis was the predominant helminth species (16.6%, 161), followed by hookworm (9.0%, 87) and Schistosoma mansoni (5.7%, 55). An infection with any helminth was not associated with TB (adjusted odds ratio (aOR) 1.26, 95% confidence interval (CI): 0.88–1.80, p = 0.22), but S. mansoni infection was (aOR 2.15, 95% CI: 1.03–4.45, p = 0.040). Moreover, S. mansoni infection was associated with lower sputum bacterial load (aOR 2.63, 95% CI: 1.38–5.26, p = 0.004) and tended to have fewer lung cavitations (aOR 0.41, 95% CI: 0.12–1.16, p = 0.088). Conclusions/Significance S. mansoni infection was an independent risk factor for active TB and altered the clinical presentation in TB patients. These findings suggest a role for schistosomiasis in modulating the pathogenesis of human TB. Treatment of helminths should be considered in clinical management of TB and TB control programs.

Home-Based and Facility-Based Directly Observed Therapy of Tuberculosis Treatment under Programmatic Conditions in Urban Tanzania.

Introduction Decentralization of Directly Observed Treatment (DOT) for tuberculosis (TB) to the community (home-based DOT) has improved the coverage of TB treatment and reduced the burden to the health care facilities (facility-based DOT). We aimed to compare TB treatment outcomes in home-based and facility-based DOT under programmatic conditions in an urban setting with a high TB burden. Methodology A retrospective analysis of a cohort of adult TB patients (≥15 years) routinely notified between 2010 and 2013 in two representative TB sub-districts in the Temeke district, Dar es Salaam, Tanzania. We assessed differences in treatment outcomes by calculating Risk Ratios (RRs). We used logistic regression to assess the association between DOT and treatment outcomes. Results Data of 4,835 adult TB patients were analyzed, with a median age of 35 years, 2,943 (60.9%) were men and TB/HIV co-infection prevalence of 39.9%. A total of 3,593 (74.3%) patients were treated under home-based DOT. Patients on home-based DOT were more likely to die compared to patients on facility-based DOT (RR 2.04, 95% Confidence Interval [95% CI]: 1.52–2.73), and more likely to complete TB treatment (RR 1.14, 95% CI: 1.06–1.23), but less likely to have a successful treatment outcome (RR 0.94, 95% CI: 0.92–0.97). Home-based DOT was preferred by women (adjusted Odds Ratio [aOR] 1.55, 95% CI: 1.34–1.80, p<0.001), older people (aOR 1.01 for each year increase, 95% CI: 1.00–1.02, p = 0.001) and patients with extra-pulmonary TB (aOR 1.45, 95% CI: 1.16–1.81, p = 0.001), but less frequently by patients on a retreatment regimen (aOR 0.12, 95% CI: 0.08–0.19, p<0.001). Conclusions/significance TB patients under home-based DOT had more frequently risk factors of death such as older age, HIV infection and sputum smear-negative TB, and had higher mortality compared to patients under facility-based DOT. Further operational research is needed to monitor the implementation of DOT under programmatic conditions.

Schistosoma, other helminth infections, and associated risk factors in preschool-aged children in urban Tanzania

Background Despite the high prevalence of helminth infections among preschool-aged children, control programs in sub-Saharan countries primarily focus on school-aged populations. We assessed the prevalence of helminth infections and determined risk factors for infection among preschool-aged children in the urban setting of Dar es Salaam, Tanzania. Methodology Starting in October 2015, we conducted a 12-month prospective study among tuberculosis (TB)-exposed children under the age of 5 years and unexposed controls from neighboring households. At the time of recruitment, we collected medical histories, assessed development and cognitive functions, and performed medical examinations. We performed full blood cell counts and screened for HIV and malaria. Point-of-care circulating cathodic antigen (POC-CCA), urine filtration, Kato-Katz, FLOTAC, and Baermann tests were employed to detect helminth infections in urine and stool. Helminth infections were stratified for Schistosoma and other helminths to identify risk factors, using logistic regression. Principal findings We included 310 children with a median age of 26 months (inter quartile range 17–42 months) in the study. Among these, 189 were TB-exposed and 121 TB-unexposed. Two thirds of the children were anemic (hemoglobin level <11 g/dl) and the HIV prevalence was 1.3%. Schistosoma spp. was the predominant helminth species (15.8%; 95% confidence interval [CI] 12.1–20.3%). Other helminth infections were less frequent (9.0%, 95% CI 6.3–12.8%). Poor hygiene, use of household water sources, and TB-exposure were not associated with helminth infection. Development and cognitive scores did not significantly differ in helminth-infected and uninfected peers, but hemoglobin levels were significantly lower in helminth-infected children (10.1 g/dl vs. 10.4 g/dl, p = 0.027). Conclusions/significance In Dar es Salaam, a city with more than 4 million inhabitants, the prevalence of Schistosoma spp. infection among preschool-aged children was unexpectedly high. Setting-specific interventions that target preschool-aged children and urban settlements should be considered to reduce the transmission of Schistosoma and other helminth infections and to improve children’s health.

Immunologic-Based Diagnosis of Latent Tuberculosis among Children Less Than 5 Years of Age Exposed and Unexposed to Tuberculosis in Tanzania: Implications for Tuberculosis Infection Screening.

Background: Childhood tuberculosis (TB) is acquired after exposure to an infectious TB case, often within the household. We prospectively screened children 6–59 months of age, exposed and unexposed to an infectious TB case within the same household, for latent tuberculosis infection (LTBI), in Dar es Salaam, Tanzania. Methods: We collected medical data and clinical specimens (to evaluate for helminths, TB and HIV coinfections) and performed physical examinations at enrollment and at 3-month and 6-month follow-up surveys. LTBI was assessed using QuantiFERON-TB Gold (QFT) at enrollment and at 3 months. Results: In total, 301 children had complete data records (186 with TB exposure and 115 without known TB exposure). The median age of children was 26 months (range: 6–58); 52% were females, and 4 were HIV positive. Eight children (3%) developed TB during the 6-month follow-up. We found equal proportions of children with LTBI among those with and without exposure: 20% (38/186) versus 20% (23/115) QFT-positive, and 2% (4/186) versus 4% (5/115) indeterminate QFT. QFT conversion rate was 7% (22 children) and reversion 8% (25 children). Of the TB-exposed children, 72% initiated isoniazid preventive therapy, but 61% of parents/caregivers of children with unknown TB exposure and positive QFT refused isoniazid preventive therapy. Conclusions: In this high burden TB setting, TB exposure from sources other than the household was equally important as household exposure. Nearly one third of eligible children did not receive isoniazid preventive therapy. Evaluation for LTBI in children remains an important strategy for controlling TB but should not be limited to children with documented TB exposure.BACKGROUND Childhood tuberculosis (TB) is acquired following exposure to an infectious TB case, often within the household. We prospectively screened children 6-59 months of age, exposed and unexposed to an infectious TB case within the same household, for latent tuberculosis infection (LTBI), in Dar es Salaam, Tanzania. METHODS We collected medical data and clinical specimens (to evaluate for helminths, TB and HIV coinfections) and performed physical examinations at enrollment and at 3-month and 6-months follow-up surveys. LTBI was assessed using QuantiFERON (QFT) at enrollment and at 3 months. RESULTS In total, 301 children had complete data records (186 with TB exposure and 115 without known TB exposure). The median age of children was 26 months (range 6-58); 52% were females, and 4 were HIV-positive. Eight children (3%) developed TB during the 6-month follow-up. We found equal proportions of children with LTBI among those with and without exposure: 20% (38/186) vs. 20% (23/115) QFT-positive, and 2% (4/186) vs. 4% (5/115) indeterminate QFT. QFT conversion rate was 7% (22 children) and reversion 8% (25 children). Of the TB-exposed children, 72% initiated isoniazid preventive therapy (IPT), but 61% of parents/caregivers of children with unknown TB exposure and positive QFT refused IPT. CONCLUSIONS In this high burden TB setting, TB exposure from sources other than the household was equally important as household exposure. Nearly one third of eligible children did not receive IPT. Evaluation for LTBI in children remains an important strategy for controlling TB, but should not be limited to children with documented TB exposure.

Improved services to enrollees into an HIV rural care and treatment center in Tanzania

Better quality of services is essential for the sustainability of HIV programs, in particular in rural Sub-Saharan Africa, to support the increasing number of individuals treated with combination antiretroviral therapy (cART). However, longitudinal data from rural care and treatment centers (CTC) are scarce. The objective was to assess trend in quality of care for HIV infected persons before start of combination antiretroviral therapy (pre-ART). A retrospective analysis of pre-ART registers and patients files of 1950 patients enrolled in the Bagamoyo CTC in Tanzania between 2008 and 2010 analyzing was conducted; with parameters including year of enrollment, gender, age, CD4 cell count and WHO clinical stage at time enrollment. We noted a significant increase by 20% of total patients who had CD4 cell count performed from 69% (n=457) in 2008, 83% (n=493) 2009 to 89% (n=616) 2010 (X2= 87.014, P2= 14.945, P2= 85.028, P3. Efforts must be undertaken for more HIV testing and timely referral of HIV-infected patients to CTC.