Background: The objective of this study was to model the predictors of HIV prevalence in Malawi through a complex sample logistic regression and spatial mapping approach using the national Demographic and Health Survey datasets. Methods: We conducted a secondary data analysis using the 2015–2016 Malawi Demographic and Health Survey and AIDS Indicator Survey. The analysis was performed in three stages while incorporating population survey sampling weights to: i) interpolate HIV data, ii) identify the spatial clusters with the high prevalence of HIV infection, and iii) perform a multivariate complex sample logistic regression. Results: In all, 14,779 participants were included in the analysis with an overall HIV prevalence of 9% (7.0% in males and 10.8% in females). The highest prevalence was found in the southern region of Malawi (13.2%), and the spatial interpolation revealed that the HIV epidemic is worse at the south-eastern part of Malawi. The districts in the high HIV prevalent zone of Malawi are Thyolo, Zomba, Mulanje, Phalombe and Blantyre. In central and northern region, the district HIV prevalence map identified Lilongwe in the central region and Karonga in the northern region as districts that equally deserve attention. People residing in urban areas had a 2.2 times greater risk of being HIV-positive compared to their counterparts in the rural areas (AOR = 2.16; 95%CI = 1.57–2.97). Other independent predictors of HIV prevalence were gender, age, marital status, number of lifetime sexual partners, extramarital partners, the region of residence, condom use, history of STI in the last 12 months, and household wealth index. Disaggregated analysis showed in-depth sociodemographic regional variations in HIV prevalence. Conclusion: These findings identify high-risk populations and regions to be targeted for Pre-Exposure Prophylaxis (PrEP) campaigns, HIV testing, treatment and education to decrease incidence, morbidity, and mortality related to HIV infection in Malawi.

• One out of four under-five children (U5C) tested positive for malaria in Ghana. • U5C older than 24 months or those severely anaemic were more likely to test positive for malaria. • U5C residing in households without electricity were more likely to test positive for malaria. • U5C residing in a rural area were more likely to test positive for malaria. • U5C residing in the poorest household were more likely to test positive for malaria.

Study Design.: Retrospective Review of Prospective cohort. Objective.: To describe the feasibility of preoperative halo gravity traction (HGT) with subsequent growing rod/guided growth (GR/GG) placement in early onset spinal deformity (EOSD). Summary of Background Data.: In children with severe EOSD, primary implantation of GR/GG constructs is not always possible. We describe a staged protocol with preoperative HGT followed by GR/GG implantation. Methods.: EOSD patients treated with HGT prior to GR/GG implantation were included. HGT used traction up to 50% body weight for 4 to 29 weeks. Pulmonary function tests (PFTs) were performed before and after HGT. Coronal Cobb (CC) and Sagittal Cobb (SC) angles were measured on the Pre-HGT, Post-HGT and 6 week postop x-rays. Results.: Thirty patients were included. Average age at GR/GG implantation was 9 years. Most cases (n = 24, 80%) were idiopathic. Most pts had kyphoscoliosis (n = 16, 53.3%). Pre-HGT CC averaged 112 ± 22° and SC averaged 106 ± 26°. CC and SC improved 29% after HGT. There was a significant improvement in body mass index following HGT. CC improved further to 70 ± 14° (36% vs. pre-HGT) and SC to 63 ± 21° (41%) with GR/GG placement. HGT-related complications occurred in nine patients (30%); eight pin site infections, one cranial abscess. Most HGT complications were managed with local pin care and oral antibiotics. Halo revision was required in two pts (6.7%). There was no change in PFTs with HGT (P > 0.05). Averagely, 14 levels were spanned during GR/GG implantation; two patients required vertebral column resection. Surgical complications occurred in nine (30%) patients. At average 16 month follow-up, seven patients (23.3%) required reoperation. Conclusion.: Preoperative HGT can make severe EOSD curves amenable to GR/GG implantation. HGT results in ∼30% correction with improvement to ∼35–40% following GR/GG. HGT has a 30% complication rate but most are pin-site infections managed with pin-site care and oral antibiotics; 6.7% of patients require revision. Level of Evidence: 4

Background: Undernutrition among children under the age of five is a major public health concern, especially in developing countries. This study aimed to use machine learning (ML) algorithms to predict undernutrition and identify its associated factors. Methods: Secondary data analysis of the 2017 Multiple Indicator Cluster Survey (MICS) was performed using R and Python. The main outcomes of interest were undernutrition (stunting: height-for-age (HAZ) < -2 SD; wasting: weight-for-height (WHZ) < -2 SD; and underweight: weight-for-age (WAZ) < -2 SD). Seven ML algorithms were trained and tested: linear discriminant analysis (LDA), logistic model, support vector machine (SVM), random forest (RF), least absolute shrinkage and selection operator (LASSO), ridge regression, and extreme gradient boosting (XGBoost). The ML models were evaluated using the accuracy, confusion matrix, and area under the curve (AUC) receiver operating characteristics (ROC). Results: In total, 8564 children were included in the final analysis. The average age of the children was 926 days, and the majority were females. The weighted prevalence rates of stunting, wasting, and underweight were 17%, 7%, and 12%, respectively. The accuracies of all the ML models for wasting were (LDA: 84%; Logistic: 95%; SVM: 92%; RF: 94%; LASSO: 96%; Ridge: 84%, XGBoost: 98%), stunting (LDA: 86%; Logistic: 86%; SVM: 98%; RF: 88%; LASSO: 86%; Ridge: 86%, XGBoost: 98%), and for underweight were (LDA: 90%; Logistic: 92%; SVM: 98%; RF: 89%; LASSO: 92%; Ridge: 88%, XGBoost: 98%). The AUC values of the wasting models were (LDA: 99%; Logistic: 100%; SVM: 72%; RF: 94%; LASSO: 99%; Ridge: 59%, XGBoost: 100%), for stunting were (LDA: 89%; Logistic: 90%; SVM: 100%; RF: 92%; LASSO: 90%; Ridge: 89%, XGBoost: 100%), and for underweight were (LDA: 95%; Logistic: 96%; SVM: 100%; RF: 94%; LASSO: 96%; Ridge: 82%, XGBoost: 82%). Age, weight, length/height, sex, region of residence and ethnicity were important predictors of wasting, stunting and underweight. Conclusion: The XGBoost model was the best model for predicting wasting, stunting, and underweight. The findings showed that different ML algorithms could be useful for predicting undernutrition and identifying important predictors for targeted interventions among children under five years in Ghana.

Study Design.: Retrospective review of prospective cohort. Objective.: We sought to examine the role of halo gravity traction (HGT) in reducing preoperative surgical risk. Summary of Background Data.: The impact of HGT on procedure choice, preoperative risk factors, and surgical complications has not been previously described. Methods.: Patients treated with HGT before primary surgery were included. The FOCOS Score (FS) was used to quantify operative risk. FS was calculated using patient-factors (ASIA, body mass index, etiology), procedure-factors (PcF; osteotomy planned, number of levels fused, etc.), and curve magnitude (CM). Scores ranged from 0 to 100 with higher scores indicating increased risk. FS was calculated before and after HGT to see how changes in FS affected complication rates. Results.: A total of 96 patients were included. Halo-related complications occurred in 34% of patients but revision was required in only 8.3%. Average FS improved by 18 points after HGT. CM, PcF, and patient-factors all improved (P < 0.05). The greatest changes were in CM and PcF. The planned rate of three-column osteotomies dropped from 91% to 38% after HGT. FS (area under the curve [AUC]: 0.68, P = 0.023) and change in FS (AUC: 0.781, P < 0.001) was successfully able to predict the rate of surgical complications. A preoperative FS of 74 was identified as a cut-off for a higher rate of surgical complications (sensitivity 58.8%, specificity 74.7%). Patients with a reduction in FS < = 10pts were five times more likely to have a complication (relative risk 5.2, 95% confidence interval: 1.9–14.6, P < 0.001). A multivariate regression showed that change in FS was an independent predictor of complication rates (P < 0.05). Conclusion.: FS can successfully predict surgical risk in pediatric patients with complex spinal deformity. Preoperative HGT can reduce FS and surgical risk by improving CM, lowering three-column osteotomies use, and improving body mass index. A reduction in FS after HGT predicts a lower rate of surgical complications. Level of Evidence: 3

Objective To examine the factors associated with recent HIV testing and to develop an HIV testing prevalence surface map using spatial interpolation techniques to identify geographical areas with low and high HIV testing rates in Ghana. Design Secondary analysis of Demographic and Health Survey. Setting Rural and urban Ghana Participants The study sample comprised 9380 women and 3854 men of 15–49 years. Results We found that 13% of women and 6% of men of Ghana had tested for HIV in the past 12 months. For women, being within the age groups of 15–39 years, being currently married, attainment of post-secondary education, having only one sexual partner and dwelling in certain regions with reference to greater Accra (Volta, Eastern, Upper West and Upper East) were associated with a higher likelihood of HIV testing. For men, being older than 19 years, attainment of post-secondary education and dwelling in the Upper East region with reference to the greater Accra region were significantly associated with a higher likelihood of HIV testing. The surface map further revealed intra-regional level differences in HIV testing estimates. Conclusion Given the results, HIV testing must be expanded with equitable testing resource allocation that target areas within the regions in Ghana with low HIV testing prevalence. Men should be encouraged to be tested for HIV.