2 research outputs found
Genetic diversity and population structure of Peronosclerospora sorghi isolates of Sorghum in Uganda
Sorghum is the third most important staple cereal crop in Uganda after maize and millet. Downy mildew disease is one of the most devastating fungal diseases which limits the production and productivity of the crop. The disease is caused by an obligate fungus, Peronosclerospora sorghi (Weston & Uppal) with varying symptoms. Information on the genetic diversity and population structure of P.sorghi in sorghum is imperative for the screening and selection for resistant genotypes and further monitoring possible mutant(s) of the pathogen. Isolates of P. sorghi infecting sorghum are difficult to discriminate when morphological descriptors are used. The use of molecular markers is efficient, and reliably precised for characterizing P. sorghi isolates. This study was undertaken to assess the level of genetic diversity and population structure that exist in P. sorghi isolates in Uganda. A total of 195 P. sorghi isolates, sampled from 13 different geographic populations from 10 different regions (agro-ecological zones) was used. Eleven (11) molecular markers, comprising of four Random amplified microsatellite (RAM) and seven (7) Inter-Simple Sequence Repeat (ISSR) markers were used in this study. The analysis of molecular variation (AMOVA) based on 11 microsatellite markers showed significant (P < 0.001) intra-population (88.9 %, PhiPT = 0.111) and inter-population (8.4 %, PhiPR = 0.083) genetic variation, while the genetic variation among regions (2.7 %, PhiRT = 0.022) was not significant. The highest genetic similarity value (0.987 = 98.7 %) was recorded between Pader and Lira populations and the lowest genetic similarity (0.913 = 91.3 %) was observed between Namutumba and Arua populations. The mean Nei's genetic diversity index (H) and Shannon Information Index (I) were 0.308 and 0.471 respectively. Seven distinct cluster groups were formed from the 195 P. sorghi isolates based on their genetic similarity. Mantel test revealed no association between genetic differentiation and geographical distance (R2 = 0.0026, p = 0.02) within the 13 geographic populations
Incidence and predictors of hospital readmission in children presenting with severe anaemia in Uganda and Malawi: a secondary analysis of TRACT trial data
Background: Severe anaemia (haemoglobin < 6 g/dL) is a leading cause of recurrent hospitalisation in African children. We investigated predictors of readmission in children hospitalised with severe anaemia in the TRACT trial (ISRCTN84086586) in order to identify potential future interventions.
Methods: Secondary analyses of the trial examined 3894 children from Uganda and Malawi surviving a hospital episode of severe anaemia. Predictors of all-cause readmission within 180 days of discharge were identified using multivariable regression with death as a competing risk. Groups of children with similar characteristics were identified using hierarchical clustering.
Results: Of the 3894 survivors 682 (18%) were readmitted; 403 (10%) had β₯2 re-admissions over 180 days. Three main causes of readmission were identified: severe anaemia (n = 456), malaria (n = 252) and haemoglobinuria/dark urine syndrome (n = 165). Overall, factors increasing risk of readmission included HIV-infection (hazard ratio 2.48
(95% CI 1.63β3.78), p < 0.001); β₯2 hospital admissions in the preceding 12 months (1.44(1.19β1.74), p < 0.001); history of transfusion (1.48(1.13β1.93), p = 0.005); and missing β₯1 trial medication dose (proxy for care quality) (1.43 (1.21β1.69), p < 0.001). Children with uncomplicated severe anaemia (Hb 4-6 g/dL and no severity features),
who never received a transfusion (per trial protocol) during the initial admission had a substantially lower risk of readmission (0.67(0.47β0.96), p = 0.04). Malaria (among children with no prior history of transfusion) (0.60(0.47β0.76), p < 0.001); younger-age (1.07 (1.03β1.10) per 1 year younger, p < 0.001) and known sickle cell disease (0.62(0.46β0.82), p = 0.001) also decreased risk of readmission. For anaemia re-admissions, gross splenomegaly and enlarged spleen increased risk by 1.73(1.23β2.44) and 1.46(1.18β1.82) respectively compared to no splenomegaly.
Clustering identified four groups of children with readmission rates from 14 to 20%. The cluster with the highest readmission rate was characterised by very low haemoglobin (mean 3.6 g/dL). Sickle Cell Disease (SCD) predominated in two clusters associated with chronic repeated admissions or severe, acute presentations in largely undiagnosed SCD. The final cluster had high rates of malaria (78%), severity signs and very low platelet count, consistent with acute severe
malaria.
Conclusions: Younger age, HIV infection and history of previous hospital admissions predicted increased risk of readmission. However, no obvious clinical factors for intervention were identified. As missing medication doses was highly predictive, attention to care related factors may be important.
Trial registration: ISRCTN ISRCTN84086586.
Keywords: Severe anaemia, Readmissio