Eugene Zwane

Loss to follow-up and mortality among pregnant women referred to a community clinic for antiretroviral treatment.

In a retrospective cohort analysis, loss to follow-up and mortality rates were compared between pregnant and nonpregnant women referred to a community-based antiretroviral treatment program in South Africa. Although there was no significant difference in adjusted mortality rates between the two groups, the pregnant women had a substantially higher risk of loss to follow-up both pretreatment and on-treatment. This finding highlights the need for programmatic interventions to address retention in care for this patient population.

Transcranial Doppler pulsatility index is not a reliable indicator of intracranial pressure in children with severe traumatic brain injury

BACKGROUND The TCD-derived PI has been associated with ICP in adult studies but has not been well investigated in children. We examined the relationship between PI and ICP and CPP in children with severe TBI. METHODS Data were prospectively collected from consecutive TCD studies in children with severe TBI undergoing ICP monitoring. Ipsilateral ICP and CPP values were examined with Spearman correlation coefficient (mean values and raw observations), with a GEE, and as binary values (1 and 20 mm Hg, respectively). RESULTS Thirty-four children underwent 275 TCD studies. There was a weak relationship between mean values of ICP and PI (P = .04, r = 0.36), but not when raw observations (P = .54) or GEE (P = .23) were used. Pulsatility index was 0.76 when ICP was lower than 20 mm Hg and 0.86 when ICP was 20 mm Hg or higher. When PI was 1 or higher, ICP was lower than 20 mm Hg in 62.5% (25 of 40 studies), and when ICP was 20 mm Hg or higher, PI was lower than 1 in 75% (46 of 61 studies). The sensitivity and specificity of a PI threshold of 1 for examining the ICP threshold of 20 mm Hg were 25% and 88%, respectively. The relationship between CPP and PI was stronger (P = .001, r = -0.41), but there were too few observations below 50 mm Hg to examine PI at this threshold. CONCLUSION The absolute value of the PI is not a reliable noninvasive indicator of ICP in children with severe TBI. Further study is required to examine the relationship between PI and a CPP threshold of 50 mm Hg.

Genital Human Papillomavirus Prevalence and Human Papillomavirus Concordance in Heterosexual Couples Are Positively Associated with Human Immunodeficiency Virus Coinfection

This study examined the concordance of genital human papillomavirus (HPV) infection in 254 heterosexually active couples and the impact of HIV coinfection. Genital HPV detection was significantly more common among HIV-infected women than among HIV-seronegative women (99 [68%] of 145 women vs. 33 [31%] of 107 women; P < .001); similarly, HPV detection was significantly more common among HIV-infected men than among HIV-seronegative men (67 [72%] of 93 and 65 [43%] of 150 men, respectively; P < .001). HIV-seronegative male partners of HIV-infected women had a significantly greater prevalence of HPV infection than did HIV-seronegative male partners of HIV-seronegative women (38 [58%] of 65 men vs. 27 [32%] of 85 men; P = .001), indicating that HIV coinfection in one partner has a significant impact on the prevalence of HPV genital infection in the other partner. HPV concordance between couples was associated with HIV infection status (P < .001, by Pearsons chi2 test) and was significantly higher among HIV-infected couples than among HIV-seronegative couples. Type-specific sharing of HPV was associated with HIV concordance status (P = .024). HIV-seronegative couples were more likely to share 1 HPV type and were unlikely to share >1 type, whereas HIV-infected or HIV-discordant couples were more likely to share >1 HPV type. Women with a high HPV load frequently shared HPV types with their male partners, suggesting that a high HPV load may play a role in HPV transmission between partners. In conclusion, HIV coinfection in one or both sexually active partners increased HPV prevalence and HPV type-specific concordance.

Pressure autoregulation, intracranial pressure, and brain tissue oxygenation in children with severe traumatic brain injury

OBJECT Cerebral pressure autoregulation is an important neuroprotective mechanism that stabilizes cerebral blood flow when blood pressure (BP) changes. In this study the authors examined the association between autoregulation and clinical factors, BP, intracranial pressure (ICP), brain tissue oxygen tension (PbtO(2)), and outcome after pediatric severe traumatic brain injury (TBI). In particular we examined how the status of autoregulation influenced the effect of BP changes on ICP and PbtO(2). METHODS In this prospective observational study, 52 autoregulation tests were performed in 24 patients with severe TBI. The patients had a mean age of 6.3 +/- 3.2 years, and a postresuscitation Glasgow Coma Scale score of 6 (range 3-8). All patients underwent continuous ICP and PbtO(2) monitoring, and transcranial Doppler ultrasonography was used to examine the autoregulatory index (ARI) based on blood flow velocity of the middle cerebral artery after increasing mean arterial pressure by 20% of the baseline value. Impaired autoregulation was defined as an ARI < 0.4 and intact autoregulation as an ARI >or= 0.4. The relationships between autoregulation (measured as both a continuous and dichotomous variable), outcome, and clinical and physiological variables were examined using multiple logistic regression analysis. RESULTS Autoregulation was impaired (ARI < 0.4) in 29% of patients (7 patients). The initial Glasgow Coma Scale score was significantly associated with the ARI (p = 0.02, r = 0.32) but no other clinical factors were associated with autoregulation status. Baseline values at the time of testing for ICP, PbtO(2), the ratio of PbtO(2)/PaO(2), mean arterial pressure, and middle cerebral artery blood flow velocity were similar in the patients with impaired or intact autoregulation. There was an inverse relationship between ARI (continuous and dichotomous) with a change in ICP (continuous ARI, p = 0.005; dichotomous ARI, p = 0.02); that is, ICP increased with the BP increase when ARI was low (weak autoregulation). The ARI (continuous and dichotomous) was also inversely associated with a change in PbtO(2) (continuous ARI, p = 0.002; dichotomous ARI, p = 0.02). The PbtO(2) increased when BP was increased in most patients, even when the ARI was relatively high (stronger autoregulation), but the magnitude of this response was still associated with the ARI. There was no relationship between the ARI and outcome. CONCLUSIONS These data demonstrate the influence of the strength of autoregulation on the response of ICP and PbtO(2) to BP changes and the variability of this response between individuals. The findings suggest that autoregulation testing may assist clinical decision-making in pediatric severe TBI and help better define optimal BP or cerebral perfusion pressure targets for individual patients.

Childhood tuberculosis infection and disease: A spatial and temporal transmission analysis in a South African township

BACKGROUND Tuberculosis (TB) remains a leading cause of mortality and morbidity in South Africa. While adult TB results from both recent and past infection, childhood TB results from recent infection and reflects ongoing transmission despite current TB control strategies. SETTING A South African community with high rates of TB and HIV disease. OUTCOMES A Geographic Information System was used to spatially and temporally define the relationships between TB exposure, infection and disease in children < 15 years of age with exposure to adult HIV-positive and HIV-negative TB disease on residential plots between 1997 and 2007. RESULTS During the study period the annual adult TB notification rate increased from 629 to 2 106/100 000 and the rate in children aged < 15 years ranged between 664/100 000 and 1 044/100 000. The mean number of exposures to adult TB for TB-uninfected children, latently TB-infected children and TB cases were 5.1%, 5.4% and 33% per annum and the mean number of adult smear-positive cases per exposed child was 1.0, 1.6 and 1.9, respectively. Acquisition of TB infection was not associated with HIV status of the adult TB case to which the child was exposed, and 36% of child TB cases were diagnosed before the temporally closest adult case on their plot. CONCLUSIONS Childhood infection and disease were quantitatively linked to infectious adult TB prevalence in an immediate social network. Childhood infection should be monitored in high-burden settings as a marker of ongoing TB transmission. Improved knowledge of township childhood and adult social networks could also facilitate targeted active case finding, which may provide an adjunct to currently failing TB control strategies.

The effect of blood transfusion on brain oxygenation in children with severe traumatic brain injury.

Objective: The indications for blood transfusion in traumatic brain injury are controversial. In particular, little is known about the effect of blood transfusion in childhood traumatic brain injury. This study aimed to examine the influence of blood transfusion on brain tissue oxygen tension in children with severe traumatic brain injury. Design: A retrospective analysis of a prospective observational database of children with severe traumatic brain injury who received brain tissue oxygen tension monitoring and a blood transfusion. Setting: University-affiliated pediatric hospital. Patients: Children with severe traumatic brain injury and blood transfusion. Interventions: None. Measurments and Main Results: Brain tissue oxygen tension was measured in normal-appearing white matter with a commercially available polarographic Clarke-type electrode. Brain tissue oxygen tension values after blood transfusion were compared with pre-transfusion values in hemodynamically stable patients. Limited interventions were allowed during the studied period. Brain tissue oxygen tension values were examined for early (1–4 hrs) and late (24 hrs) changes after blood transfusion, controlling for multiple clinical and physiologic variables with regression techniques. Further comparison was made with matched non-transfused controls to examine the influence of time after injury. Nineteen blood transfusions in 17 patients were evaluated. Brain tissue oxygen tension increased significantly in the early period after blood transfusion (p = .0018; 79% increased, 21% decreased) in comparison with baseline values and matched controls, but the overall changes were small and, in part, influenced by accompanying cerebral perfusion pressure changes. Also, this effect was limited to the early period after blood transfusion and was not significant after 24 hrs. In general, the brain tissue oxygen tension increase was larger in patients with higher baseline brain tissue oxygen tension and lower initial hemoglobin; however, no factors associated with the magnitude of the brain tissue oxygen tension change were significant in multivariate analysis. Increased age of blood did not appear to impair brain tissue oxygen tension changes, but most blood transfusion were <14 days old. Conclusions: Brain tissue oxygen tension increased transiently in 79% of blood transfusion in pediatric traumatic brain injury patients, and decreased transiently in 21%. Brain tissue oxygen tension returned to baseline within 24 hrs. Reliable predictors of this brain tissue oxygen tension response to blood transfusion, however, remain elusive.

Acute clinical grading in pediatric severe traumatic brain injury and its association with subsequent intracranial pressure, cerebral perfusion pressure, and brain oxygenation

OBJECT The goal of this paper was to examine the relationship between methods of acute clinical assessment and measures of secondary cerebral insults in severe traumatic brain injury in children. METHODS Patients who underwent intracranial pressure (ICP), cerebral perfusion pressure (CPP), and brain oxygenation (PbtO(2)) monitoring and who had an initial Glasgow Coma Scale score, Pediatric Trauma Score, Pediatric Index of Mortality 2 score, and CT classification were evaluated. The relationship between these acute clinical scores and secondary cerebral insult measures, including ICP, CPP, PbtO(2), and systemic hypoxia were evaluated using univariate and multivariate analysis. RESULTS The authors found significant associations between individual acute clinical scores and select physiological markers of secondary injury. However, there was a large amount of variability in these results, and none of the scores evaluated predicted each and every insult. Furthermore, a number of physiological measures were not predicted by any of the scores. CONCLUSIONS Although they may guide initial treatment, grading systems used to classify initial injury severity appear to have a limited value in predicting who is at risk for secondary cerebral insults.

Imaging Features of the Brain, Cerebral Vessels and Spine in Pediatric Tuberculous Meningitis With Associated Hydrocephalus.

Background: Pediatric tuberculous meningitis (TBM) leads to high rates of mortality and morbidity. Prompt diagnosis and initiation of treatment are challenging; imaging findings play a key role in establishing the presumptive diagnosis. General brain imaging findings are well reported; however, specific data on cerebral vascular and spinal involvement in children are sparse. Methods: This prospective cohort study examined admission and followed up computed tomography brain scans and magnetic resonance imaging scans of the brain, cerebral vessels (magnetic resonance angiogram) and spine at 3 weeks in children treated for TBM with hydrocephalus (HCP; inclusion criteria). Exclusion criteria were no HCP on admission, treatment of HCP or commencement of antituberculosis treatment before study enrollment. Imaging findings were examined in association with outcome at 6 months. Results: Forty-four patients (median age 3.3 [0.3–13.1] years) with definite (54%) or probable TBM were enrolled. Good clinical outcome was reported in 72%; the mortality rate was 16%. Infarcts were reported in 66% of patients and were predictive of poor outcome. Magnetic resonance angiogram abnormalities were reported in 55% of patients. Delayed tuberculomas developed in 11% of patients (after starting treatment). Spinal pathology was more common than expected, occurring in 76% of patients. Exudate in the spinal canal increased the difficulty of lumbar puncture and correlated with high cerebrospinal fluid protein content. Conclusion: TBM involves extensive pathology in the central nervous system. Severe infarction was predictive of poor outcome although this was not the case for angiographic abnormalities. Spinal disease occurs commonly and has important implications for diagnosis and treatment. Comprehensive imaging of the brain, spine and cerebral vessels adds insight into disease pathophysiology.