Pneumococcal acquisition among infants exposed to HIV in rural Malawi:a longitudinal household study

The prevalence of Streptococcus pneumoniae (pneumococcus) carriage is higher in adults who are infected with human immunodeficiency virus (HIV) than in adults who are not. We hypothesized that infants exposed to HIV become carriers of nasopharyngeal pneumococcus earlier and more frequently than infants who are not exposed to HIV. We compared infant pneumococcal acquisition by maternal HIV status and household exposure in Karonga District, Malawi, in 2009-2011, before the introduction of pneumococcal conjugate vaccine. Nasopharyngeal swabs were collected every 4-6 weeks in the first year of life from infants with known HIV-exposure status, their mothers, and other household members. We studied infant pneumococcal acquisition by maternal HIV status, serotype-specific household exposure, and other risk factors, including seasonality. We recruited 54 infants who were exposed to HIV and 131 infants who were not. There was no significant difference in pneumococcal acquisition by maternal HIV status (adjusted rate ratio (aRR) = 1.00, 95% confidence interval (CI): 0.87, 1.15). Carriage by the mother was associated with greater acquisition of the same serotype (aRR = 3.09, 95% CI: 1.47, 6.50), but the adjusted population attributable fraction was negligible (1.9%, 95% CI: 0.0, 4.3). Serotype-specific exposure to children under 5 years of age was associated with higher acquisition (aRR = 4.30, 95% CI: 2.80, 6.60; adjusted population attributable fraction = 8.8%, 95% CI: 4.0, 13.4). We found no evidence to suggest that maternal HIV infection would affect the impact of pneumococcal vaccination on colonization in this population

Pneumococcal carriage in households in Karonga District, Malawi, before and after introduction of 13-valent pneumococcal conjugate vaccination.

BACKGROUND Thirteen-valent pneumococcal conjugate vaccine (PCV13) was introduced in Malawi in November 2011 and is offered to infants at 6, 10 and 14 weeks of age as part of routine immunisation. PCV13 is expected to reduce vaccine type (VT) nasopharyngeal carriage, leading to reduced transmission and herd protection. METHODS We compared pneumococcal carriage in rural Karonga District, Malawi, pre-vaccine in 2009-2011 and post-vaccine in 2014 using a combination of cross-sectional and longitudinal analyses. Nasopharyngeal swabs were collected from a cohort of mother-infant pairs and household members <16 years. Pneumococci from 2009 to 2011 were serogrouped using latex agglutination and serotyped by Quellung reaction. In 2014, latex agglutination was used for both steps. Carriage prevalence ratios using prevalence data from before and after vaccine introduction were calculated by log-binomial regression, adjusted for age, seasonality and household composition. Participating infants in 2014 received PCV13 as part of routine immunisation. RESULTS VT carriage prior to PCV-13 introduction was 11.4%, 45.1%, 28.2%, 21.2% and 6.6% for 6-week old infants, 18-week old infants, children 1-4 years, children 5-15 years and mothers, respectively. After vaccine introduction, VT carriage decreased among vaccinated 18-week old infants (adjusted prevalence ratio 0.24 (95%CI 0.08-0.75)), vaccinated children 1-4 years (0.54 (0.33-0.88)), unvaccinated children 5-15 years (0.37 (0.17-0.78)) and mothers (0.34 (0.15-0.79)). No decrease in VT carriage was observed for 6-week old infants too young to be vaccinated (1.07 (0.38-3.02)) and PCV-13 ineligible children 1-4 years (0.84 (0.53-1.33)). Non-VT carriage increased only among vaccinated children 1-4 years (1.58 (1.21-2.06)). CONCLUSIONS There is evidence of reduced VT pneumococcal carriage three years after vaccine introduction in this rural Malawian population with good vaccine coverage using a 3 + 0 schedule. However carriage was sustained among 6-week-old infants and PCV13 ineligible 1-4 year olds, and there was some indication of serotype replacement in vaccinated 1-4 year olds

Community-Level Knowledge and Perceptions of Stroke in Rural Malawi.

Background and Purpose- The incidence of stroke in Malawi is unknown but major risk factors, including hypertension, obesity, and diabetes mellitus, are highly prevalent. We sought to understand community-level knowledge about stroke. Methods- A population-based cross-sectional study was conducted in rural Malawi (2016-2017). Adults aged ≥15 years were randomly selected and interviewed about their knowledge and perceptions of stroke symptoms, risk factors, and prevention. Logistic regression was used to investigate sociodemographic factors associated with stroke knowledge. Results- Of 812 selected, 739 (91% response rate) were seen and consented; 57% were female, and the median age was 52.0 years. Knowledge of stroke was poor: 71% knew no (correct) risk factors. Witchcraft (20.6%) was mentioned as frequently as hypertension (19.8%) as a cause. Knowledge of stroke was greatest in the most educated and wealthy and lowest in men, the never married, and the youngest age group. HIV-positive individuals had higher knowledge of prevention (odds ratio, 2.91; 95% CI, 1.21-7.03) than HIV negative individuals. Conclusions- Knowledge about stroke is very low in this community, particularly among the least educated and poor. Programs to support prevention, early recognition, and timely hospital presentation after a stroke are needed

The renal angina index accurately predicts low risk of developing severe acute kidney injury among children admitted to a low-resource pediatric intensive care unit

AbstractBackground Acute kidney injury (AKI) increases the risk of adverse outcomes. The renal angina index (RAI) has previously been used to predict patients at risk of developing severe AKI (sAKI).Method This single-centre prospective observational study aimed to assess the prevalence of sAKI in PICU as the primary outcome and the duration of mechanical ventilation and PICU stay, RRT need, and mortality as secondary outcomes. The utility of the RAI in predicting day 3 sAKI was also assessed. We enrolled 122 patients aged 1 month to 16 years whose baseline characteristics were collected via questionnaire. RAI was calculated on day 0 with a score of ≥8 being considered positive. sAKI was defined as KDIGO stages 2 and 3.Results sAKI prevalence was 14.8% and its development was associated with longer duration of mechanical ventilation (p = 0.001) and higher mortality (p = 0.011). A positive Day 0 RAI predicted day 3 sAKI with sensitivity 55.6%, specificity 85.6%, PPV 40.0%, NPV 91.8%, and AUC of 0.77. Exclusion of children older than 5 years improved RAI performance (sensitivity 72.7%, specificity 88.0%, PPV 57.1%, NPV 93.6%, AUC 0.80). A modified RAI based on local AKI risk factors had equivalent performance to RAI (Z – score 0.78 (CI −0.077–0.033), p = 0.435) with sensitivity 72.2%, specificity 80.8%, PPV 39.4%, NPV 94.4% and AUC 0.80.Conclusion The RAI can be an effective tool in ruling out sAKI in patients and a modification of RAI based on population-based risk factors improves the test’s sensitivity and NPV

Identification of immunological biomarkers which may differentiate latent tuberculosis from exposure to environmental nontuberculous mycobacteria in children.

A positive gamma interferon (IFN-γ) response to Mycobacterium tuberculosis early secretory antigenic target-6 (ESAT-6)/culture filtrate protein-10 (CFP-10) has been taken to indicate latent tuberculosis (TB) infection, but it may also be due to exposure to environmental nontuberculous mycobacteria in which ESAT-6 homologues are present. We assessed the immune responses to M. tuberculosis ESAT-6 and cross-reactive responses to ESAT-6 homologues of Mycobacterium avium and Mycobacterium kansasii. Archived culture supernatant samples from children at 3 years post-BCG vaccination were tested for cytokine/chemokine responses to M. tuberculosis antigens. Furthermore, the IFN-γ responses to M. tuberculosis antigens were followed up for 40 children at 8 years post-BCG vaccination, and 15 TB patients were recruited as a control group for the M. tuberculosis ESAT-6 response in Malawi. IFN-γ enzyme-linked immunosorbent assays (ELISAs) on supernatants from diluted whole-blood assays, IFN-γ enzyme-linked immunosorbent spot (ELISpot) assays, QuantiFERON TB Gold-In Tube tests, and multiplex bead assays were performed. More than 45% of the responders to M. tuberculosis ESAT-6 showed IFN-γ responses to M. avium and M. kansasii ESAT-6. In response to M. tuberculosis ESAT-6/CFP-10, interleukin 5 (IL-5), IL-9, IL-13, and IL-17 differentiated the stronger IFN-γ responders to M. tuberculosis ESAT-6 from those who preferentially responded to M. kansasii and M. avium ESAT-6. A cytokine/chemokine signature of IL-5, IL-9, IL-13, and IL-17 was identified as a putative immunological biosignature to differentiate latent TB infection from exposure to M. avium and M. kansasii in Malawian children, indicating that this signature might be particularly informative in areas where both TB and exposure to environmental nontuberculous mycobacteria are endemic

Anforderungen an die FABEL-Sprache

SIGLEAvailable from TIB Hannover: RR 3215(11) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman