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Endemic Burkitt lymphoma (eBL) is a pediatric cancer coendemic with malaria in sub-Saharan Africa, suggesting an etiological link between them. However, previous cross-sectional studies of limited geographic areas have not found a convincing association. We used spatially detailed data from the Epidemiology of Burkitt Lymphoma in East African Children and Minors (EMBLEM) study to assess this relationship. EMBLEM is a case–control study of eBL from 2010 through 2016 in six regions of Kenya, Uganda, and Tanzania. To measure the intensity of exposure to the malaria parasite, Plasmodium falciparum, among children in these regions, we used high-resolution spatial data from the Malaria Atlas Project to estimate the annual number of P. falciparum infections from 2000 through 2016 for each of 49 districts within the study region. Cumulative P. falciparum exposure, calculated as the sum of annual infections by birth cohort, varied widely, with a median of 47 estimated infections per child by age 10, ranging from 4 to 315 infections. eBL incidence increased 39% for each 100 additional lifetime P. falciparum infections (95% CI: 6.10 to 81.04%) with the risk peaking among children aged 5 to 11 and declining thereafter. Alternative models using estimated annual P. falciparum infections 0 to 10 y before eBL onset were inconclusive, suggesting that eBL risk is a function of cumulative rather than recent cross-sectional exposure. Our findings provide population-level evidence that eBL is a phenotype related to heavy lifetime exposure to P. falciparum malaria and support emphasizing the link between malaria and eBL. [ABSTRACT FROM AUTHOR]

Summary: Platelet counts are decreased in Plasmodium falciparum malaria, which is aetiologically linked with endemic Burkitt lymphoma (eBL). However, the pattern of platelet counts in eBL cases is unknown. We studied platelet counts in 582 eBL cases and 2 248 controls enrolled in a case‐control study in Uganda, Tanzania and Kenya (2010–2016). Mean platelet counts in controls or eBL cases with or without malaria‐infection in controls versus eBLcases were compared using Student's t‐test. Odds ratios (ORs) and two‐sided 95% confidence intervals (95% CIs) were estimated using multiple logistic regression, controlling for age, sex, haemoglobin and white blood cell counts. Platelets were decreased with malaria infection in the controls [263 vs. 339 × 109 platelets/l, P < 0·0001; adjusted OR (aOR) = 3·42, 95% CI: 2·79–4·18] and eBL cases (314 vs. 367 × 109 platelets/l, P‐value = 0·002; aOR = 2·36, 95% CI: 1·49–3·73). Unexpectedly, platelets were elevated in eBL cases versus controls in overall analyses (mean: 353 vs. 307 × 109 platelets/l, P < 0·0001; aOR = 1·41; 95% CI: 1·12–1·77), and when restricted to malaria‐positive (mean 314 vs. 263 × 109 platelets/l, P < 0·0001; OR = 2·26; 95% CI: 1·56–3·27) or malaria‐negative (mean 367 vs. 339 × 109 platelets/l, P < 0·001; OR = 1·46; 95% CI: 1·17–1·83) subjects. Platelets were decreased with malaria infection in controls and eBL cases but elevated with eBL. [ABSTRACT FROM AUTHOR]

Summary: Endemic Burkitt lymphoma (eBL) is an aggressive childhood B‐cell lymphoma associated with Plasmodium falciparum (Pf) malaria and Epstein–Barr virus (EBV) infections. Variation in the Human Leukocyte Antigen (HLA) system is suspected to play a role, but assessments using less accurate serology‐based HLA typing techniques in small studies yielded conflicting results. We studied 200 eBL cases and 400 controls aged 0–15 years enrolled in northern Uganda and typed by accurate high‐resolution HLA sequencing methods. HLA results were analyzed at one‐ or two‐field resolution. Odds ratios and 95% confidence intervals (aOR, 95% CI) for eBL risk associated with common HLA alleles versus alleles that were rare (<1%) or differed by <2% between the cases and controls as the reference category, were estimated using multiple logistic regression adjusting for age, sex, microgeography, region, malaria positivity and treatment history, and genetic variants associated with eBL. Compared to the controls, eBL cases had a lower frequency of HLA‐A*02 (aOR = 0·59, 95% CI 0·38–0·91), HLA‐B*41 (aOR = 0·36, 95% CI 0·13–1·00), and HLA‐B*58 alleles (aOR = 0·59, 95% CI 0·36–0·97). eBL cases had a lower frequency of HLA‐DPB1 homozygosity (aOR = 0·57, 95% CI 0·40–0·82) but a higher frequency of HLA‐DQA1 homozygosity (aOR = 2·19, 95% CI 1·42–3·37). Our results suggest that variation in HLA may be associated with eBL risk. [ABSTRACT FROM AUTHOR]

Endemic Burkitt lymphoma (eBL) is the most common childhood cancer in sub‐Saharan African countries, however, few epidemiologic studies have been undertaken and none attempted enrolling cases from multiple countries. We therefore conducted a population‐based case–control study of eBL in children aged 0–15 years old in six regions in Northern Uganda, Northern Tanzania and Western Kenya, enrolling 862 suspected cases and 2,934 population controls (response rates 98.5–100%), and processing ~40,000 vials of samples using standardized protocols. Risk factor questionnaires were administered, and malaria period prevalence was measured using rapid diagnostic tests (RDTs). A total of 80.9% of the recruited cases were diagnosed as eBL; 61.4% confirmed by histology. Associations with eBL risk were computed using logistic regression models adjusted for relevant confounders. Associations common in at least two countries were emphasized. eBL risk was decreased with higher maternal income and paternal education and elevated with history of inpatient malaria treatment >12 months before enrollment. Reporting malaria‐attributed fever up to 6 months before enrollment and malaria‐RDT positivity at enrollment were associated with decreased eBL risk. Conversely, reporting exposure to mass malaria suppression programs (e.g., indoor residual insecticide) was associated with elevated risk. HIV seropositivity was associated with elevated eBL risk, but the relative impact was small. The study shows that it is feasible to conduct networked, multisite population‐based studies of eBL in Africa. eBL was inversely associated with socioeconomic status, positively associated with inpatient malaria treatment 12 months ago and with living in areas targeted for malaria suppression, which support a role of malaria in eBL. What's new? Endemic Burkitt lymphoma (eBL) is the most common childhood cancer in sub‐Saharan Africa, but there have been few epidemiologic studies. In this multi‐country analysis, the authors used harmonized protocols to investigate infectious, environmental, and other risk factors for eBL. Socioeconomic status and recent malarial fever were associated with reduced eBL risk, while HIV infection, previous malaria, and living in areas targeted for malaria suppression increased eBL risk. These results provide new baseline data regarding eBL epidemiology, indicating that malaria may play a role. They also confirm the feasibility of multi‐site, population‐based enrolment for crucial future eBL studies. [ABSTRACT FROM AUTHOR]

Background: Falciparum malaria is an important risk factor for African Burkitt lymphoma (BL), but few studies have evaluated malaria patterns in healthy BL-age children in populations where both diseases are endemic. To obtain accurate current data, patterns of asymptomatic malaria were investigated in northern Uganda, where BL is endemic. Methods: Between 2011 and 2015, 1150 apparently healthy children under 15 years old were sampled from 100 villages in northern Uganda using a stratified, multi-stage, cluster survey design. Falciparum malaria prevalence (pfPR) was assessed by questionnaire, rapid diagnostic test (RDT) and thick film microscopy (TFM). Weighted pfPR and unadjusted and adjusted associations of prevalence with covariates were calculated using logistic models and survey methods. Results: Based on 1143 children successfully tested, weighted pfPR was 54.8% by RDT and 43.4% by TFM. RDT sensitivity and specificity were 97.5 and 77.8%, respectively, as compared to TFM, because RDT detect malaria antigens, which persist in peripheral blood after clinical malaria, thus results based on RDT are reported. Weighted pfPR increased from 40% in children aged under 2 years to 61.8% in children aged 6-8 years (odds ratio 2.42, 95% confidence interval (CI) 1.26-4.65), then fell slightly to 49% in those aged 12-15 years. Geometric mean parasite density was 1805.5 parasites/µL (95% CI 1344.6-2424.3) among TFM-positive participants, and it was higher in children aged <5 years at 5092.9/µL (95% CI 2892.7-8966.8) and lower in those aged ≥10 years at 983.8/µL (95% CI 472.7- 2047.4; P = 0.001). Weighted pfPR was lower in children residing in sub-regions employing indoor residual spraying (IRS) than in those residing in non-IRS sub-regions (32.8 versus 65.7%; OR 0.26, 95% CI 0.14, 0.46). However, pfPR varied both within IRS (3.2-55.3%) and non-IRS sub-regions (29.8-75.8%; Pheterogeneity <0.001). pfPR was inversely correlated with a child's mother's income (P = 0.011) and positively correlated with being enrolled in the wet season (P = 0.076), but sex was irrelevant. Conclusions: The study observed high but geographically and demographically heterogenous patterns of asymptomatic malaria prevalence among children living in northern Uganda. These results provide important baseline data that will enable precise evaluation of associations between malaria and BL. [ABSTRACT FROM AUTHOR]

Background: Plasmodium falciparum malaria is an important cause of morbidity in northern Uganda. This study was undertaken to assess village-, household-, and individual-level risk factors of asymptomatic falciparum malaria in children in 12 villages in northern Uganda. Methods: Between 10/2011 and 02/2014, 1006 apparently healthy children under 16 years old were enrolled in 12 villages using a stratified, multi-stage, cluster survey design and assessed for P. falciparum malaria infection using the rapid diagnostic test (RDT) and thick film microscopy (TFM), and structured interviewer-administered questionnaires. Associations between weighted P. falciparum malaria prevalence (pfPR), based on RDT, and covariates were estimated as odds ratios and 95% confidence intervals (ORs, 95% CIs) using logistic models accounting for the survey design. Results: Among 942 (93.5%) children successfully tested, pfPR was 52.4% by RDT and 32.7% by TFM. Overall pfPR was lower in villages where indoor residual insecticide spray (IRS) was, versus not, implemented (18.4% versus 75.2%, P < 0.0001). However, pfPR was heterogeneous both within IRS (10.6–34.8%) and non-IRS villages (63.6–86.2%). Elevated pfPR was associated with having a sibling who was RDT positive (OR 5.39, 95% CI 2.94–9.90, P = 0.0006) and reporting a fever at enrollment (aOR 4.80, 95% CI 1.94–11.9, P = 0.0094). Decreased pfPR was associated with living in an IRS village (adjusted OR 0.06, 95% CI 0.04–0.07, P < 0.0001), in a household with one (aOR 0.48, 95% CI 0.30–0.76) or more than one child below 5 years (aOR 0.23, 95% CI 0.12–0.44, Ptrend = 0.014), and reporting keeping a goat inside or near the house (aOR 0.42, 95% CI 0.29–0.62, P = 0.0021). Conclusions: The results show high but heterogeneous pfPR in villages in northern Uganda, confirm significantly decreased pfPR associated with IRS implementation, and suggest significant associations with some household characteristics. Further research is needed to elucidate the factors influencing malaria heterogeneity in villages in Uganda. [ABSTRACT FROM AUTHOR]