Follow-up of a suspected excess of brain tumours among Namibian children

The original publication is available at http://www.samj.org.zaTo the Editor: The aim of this follow-up study was to further investigate a suggested excess of childhood brain tumours (CBT) among Herero children in Namibia from 1983 to 1988. Incidence rates of primary brain tumours among Herero children were found to be 4 times higher than rates among Namibian children in any of the 10 other tribal groups or among children of European origin. The causes of CBTs remain largely unknown. The only established causes are ionizing radiation and predisposing inherited syndromes. A particularly compelling hypothesis is that exposure during gestation to N-nitroso compounds (NOCs) may lead to the development of CBT. This hypothesis was suggested by experimental work in which 100% production of nervous system (NS) tumours in rat offspring resulted from transplacental exposure to the neurocarcinogen ethylnitrosourea (ENU) or to low levels of the precursor compounds sodium nitrite and ethyl urea added to the food and drinking water of pregnant rat

Kaposi’s sarcoma: Good outcome with doxorubicin, bleomycin and vincristine sulphate (ABV) chemotherapy and highly active antiretroviral therapy

There is little published information on effective treatment of Kaposi’s sarcoma (KS) in children in low-income countries. We prospectively treated 12 patients with an institutional review board-approved protocol consisting of four monthly courses of doxorubicin (Adriamycin), bleomycin and vincristine sulphate (ABV), with highly active antiretroviral therapy (HAART) plus co-trimoxazole prophylaxis for those who were HIV-positive, with additional vincristine if remission was not achieved after 4 months. Maintenance HAART plus co-trimoxazole was given to all HIV-positive patients. A fine-needle aspirate and CD4+ count were done if possible, and staging was performed according to Mitsuyasu. Eight of ten HIV-positive patients with stage III - IVB disease, and both HIV-negative patients with stage I disease, were in remission after 473 - 1 490 (mean 939) days. One patient died after absconding during treatment, and one died from neutropenia-related pulmonary infection. ABV with or without HAART is an effective treatment option for children with KS

Burkitt's lymphoma: The prevalence of HIV/AIDS and the outcome of treatment

The prevalence of HIV in Burkitt’s lymphoma (BL) patients and the outcome of treatment in Cameroon were unknown. Records of all patients diagnosed with BL at three Cameroon Baptist Convention hospitals were reviewed to ascertain the recorded HIV status and outcome of treatment. Of 979 patients diagnosed with BL, 717 were tested for HIV and 11 (1.5%) were HIV-positive. Three of eight patients treated with both cyclophosphamide (CPM)-based chemotherapy and antiretrovirals were alive at 62, 96 and 111 months, respectively. The HIV rate was comparable to that of 1% for the general population of children aged <15 years. Low-cost high-frequency CPM was the only available treatment option for BL and was associated with 37.5% long-term survival in a resource-limited setting

Optimising computer aided detection to identify intra-thoracic tuberculosis on chest x-ray in South African children

Diagnostic tools for paediatric tuberculosis remain limited, with heavy reliance on clinical algorithms which include chest x-ray. Computer aided detection (CAD) for tuberculosis on chest x-ray has shown promise in adults. We aimed to measure and optimise the performance of an adult CAD system, CAD4TB, to identify tuberculosis on chest x-rays from children with presumptive tuberculosis. Chest x-rays from 620 children <13 years enrolled in a prospective observational diagnostic study in South Africa, were evaluated. All chest x-rays were read by a panel of expert readers who attributed each with a radiological reference of either 'tuberculosis' or 'not tuberculosis'. Of the 525 chest x-rays included in this analysis, 80 (40 with a reference of 'tuberculosis' and 40 with 'not tuberculosis') were allocated to an independent test set. The remainder made up the training set. The performance of CAD4TB to identify 'tuberculosis' versus 'not tuberculosis' on chest x-ray against the radiological reference read was calculated. The CAD4TB software was then fine-tuned using the paediatric training set. We compared the performance of the fine-tuned model to the original model. Our findings were that the area under the receiver operating characteristic curve (AUC) of the original CAD4TB model, prior to fine-tuning, was 0.58. After fine-tuning there was an improvement in the AUC to 0.72 (p = 0.0016). In this first-ever description of the use of CAD to identify tuberculosis on chest x-ray in children, we demonstrate a significant improvement in the performance of CAD4TB after fine-tuning with a set of well-characterised paediatric chest x-rays. CAD has the potential to be a useful additional diagnostic tool for paediatric tuberculosis. We recommend replicating the methods we describe using a larger chest x-ray dataset from a more diverse population and evaluating the potential role of CAD to replace a human-read chest x-ray within treatment-decision algorithms for paediatric tuberculosis

Prophylactic Effect of a Therapeutic Vaccine against TB Based on Fragments of Mycobacterium tuberculosis

The prophylactic capacity of the RUTI® vaccine, based on fragmented cells of Mycobacterium tuberculosis, has been evaluated in respect to aerosol challenge with virulent bacilli. Subcutaneous vaccination significantly reduced viable bacterial counts in both lungs and spleens of C57Bl mice, when challenged 4 weeks after vaccination. RUTI® protected the spleen less than BCG. Following a 9 month vaccination-challenge interval, protection was observed for the lungs, but not for the spleen. Survival of infected guinea pigs was prolonged by vaccination given 5 weeks before challenge. Inoculations of RUTI® shortly after infection significantly reduced the viable bacterial counts in the lungs, when compared with infected control mice. Thus, vaccination by RUTI® has potential for both the prophylaxis and immunotherapy of tuberculosis

Burkitt’s lymphoma patients in Northwest Cameroon have a lower incidence of sickle cell trait (Hb AS) than healthy controls

Contradictory findings have been reported from Africa with regard to the risk of developing Burkitt’s lymphoma (BL) in sickle cell trait (AS)carriers. Haemoglobin electrophoresis was performed in 78 BL patients in the Northwest region of Cameroon, and in 78 nearest-neighbourcontrols of the same age, sex and tribe from the same village. AS was confirmed in 4 of 78 (5.13%) BL patients and in 11 of 78 (14.10%)controls (χ2, p=0.052; Fisher’s exact, one-tailed, p=0.050). Sickle cell trait carriers had a marginal statistically reduced risk of developing BL

Lessons for TB from the COVID-19 response: qualitative data from Brazil, India and South Africa

BACKGROUND: Brazil, India and South Africa are among the top 30 high TB burden countries globally and experienced high rates of SARS-CoV-2 infection and mortality. The COVID-19 response in each country was unprecedented and complex, informed by distinct political, economic, social and health systems contexts. While COVID-19 responses have set back TB control efforts, they also hold lessons to inform future TB programming and services. METHODS: This was a qualitative exploratory study involving interviews with TB stakeholders (n = 76) in Brazil, India and South Africa 2 years into the COVID-19 pandemic. Interview transcripts were analysed using an inductive coding strategy. RESULTS: Political will – whether national or subnational – enabled implementation of widespread prevention measures during the COVID-19 response in each country and stimulated mobile and telehealth service delivery innovations. Participants in all three countries emphasised the importance of mobilising and engaging communities in public health responses and noted limited health education and information as barriers to implementing TB control efforts at the community level. CONCLUSIONS: Building political will and social mobilisation must become more central to TB programming. COVID-19 has shown this is possible. A similar level of investment and collaborative effort, if not greater, as that seen during the COVID-19 pandemic is needed for TB through multi-sectoral partnerships

The polycystic kidney disease 1 gene encodes a 14 kb transcript and lies within a duplicated region on chromosome 16

Autosomal dominant polycystic kidney disease (ADPKD) is a common genetic disorder that frequently results in renal fallure due to progressive cyst development. The major locus, PKD1, maps to 16p13.3. We identified a chromosome translocation associated with ADPKD that disrupts a gene (PBP) encoding a 14 kb transcript in the PKD1 candidate region. Further mutations of the PBP gene were found in PKD1 patients, two deletions (one a de novo event) and a splicing defect, confirming that PBP is the PKD1 gene. This gene is located adjacent to the TSC2 locus in a genomic region that is reiterated more proximally on 16p. The duplicate area encodes three transcripts substantially homologous to the PKD1 transcript. Partial sequence analysis of the PKD1 transcript shows that it encodes a novel protein whose function is at present unknown