Review: Why permanent control of cassava Brown streak disease in sub Saharan Africa have remained a dream come true since 1930s?

Bemisia tabaci is an important vector of cassava brown streak viruses and cassava mosaic begomoviruses, the causal agents of cassava brown streak disease and cassava mosaic disease (CMD), respectively. A study was carried out to determine the genetic variability of B. tabaci associated with cassava and the occurrence of CMD in Zambia in 2013 and 2015. Phylogenetic analysis showed the presence of only the sub-Saharan Africa 1 (SSA1) genetic group in Zambia. The SSA1 population had three population subgroups (SGs): SSA1-SG1, SSA1-SG2 and SSA1-SG3. All three SSA1 population subgroups occurred in Western Province. However, only SSA1-SG3 occurred in Eastern Province, while only SSA1-SG1 occurred in North Western and Luapula Provinces. Adult B. tabaci were most abundant in Western Province in 2013 (11.1/plant) and 2015 (10.8/plant), and least abundant (0.2/plant) in Northern Province in both 2013 and 2015. CMD was prevalent in all seven provinces surveyed, with the highest incidence recorded in Lusaka Province in both 2013 (78%) and 2015 (83.6%), and the lowest in Northern Province in both 2013 (26.6%) and 2015 (29.3%). Although SSA1-SG1 occurred at greater abundances than the other subgroups, there was no direct association demonstrated between whitefly subgroup and incidence of CMD. Establishing which B. tabaci genetic groups and populations are associated with CMD and their distribution in the country is a key factor in guiding the development of CMD control strategies for cassava-dependent households.

Download Full-text

Influence of Genotype, Location and Plant Age on Incidence and Severity of Cassava Mosaic and Cassava Brown Streak Diseases in Western Kenya

Journal of Experimental Agriculture International ◽

10.9734/jeai/2020/v42i630543 ◽

2020 ◽

pp. 86-104

Author(s):

L. N. Navangi ◽

S. M. Githiri ◽

E. M. Ateka ◽

E. Kanju ◽

S. Tumwegamire ◽

...

Keyword(s):

Significant Interaction ◽

Sub Saharan Africa ◽

Location Analysis ◽

Effective Management ◽

Western Kenya ◽

Balanced Design ◽

Sub Saharan ◽

Location Map ◽

Resistant Genotypes ◽

Brown Streak

This study aimed to assess elite cassava genotypes for resistance to cassava mosaic and brown streak diseases at Alupe, Kakamega and Kibos in Western Kenya. The trial was conducted using alpha lattice balanced design using 24 genotypes with three replicates, for an extended cropping cycle between 2016 and 2017. Results for combined analysis of variance showed that genotype, location, month after planting (MAP) and their interactions significantly influenced (P ≤ 0.05) incidence and severity of CMD and CBSD. High CMD incidence and severity was recorded across all cassava genotypes at Alupe (mean 0.730; 1.256) as opposed to Kakamega (mean 0.000; 1.000) and Kibos (mean 0.031; 1.006). Similarly, CBSD root incidence and severity were high in Alupe (mean 0.848; 1.310), as opposed to Kakamega (mean 0.020; 1.006) and Kibos (mean 0.188; 1.078). Within location analysis for CMD and CBSD incidence and severity among cassava genotypes 12 MAP gave varied results. Genotypes Kibandameno and Kalawe had the highest CMD and CBSD incidence and severity in all three locations. Whiteflies abundance was significantly influenced (P ≤ 0.05) by genotype, location, MAP time and interaction. Significant interaction (P ≤ 0.05) between all disease resistance traits further confirmed dual resistance amongst the cassava genotypes, however, this was location specific and not generalized. These findings should be of value to cassava breeding and development efforts throughout Kenya, and other parts of sub Saharan Africa affected or threatened by CMD and CBSD and will hopefully contribute to the development of much improved and/or resistant genotypes and, ultimately more effective management of two of Africa's most pernicious threats to food security

Download Full-text

RTS,S/AS01, a vaccine targeting pre-erythrocytic stages of Plasmodium falciparum

Emerging Topics in Life Sciences ◽

10.1042/etls20170101 ◽

2017 ◽

Vol 1 (6) ◽

pp. 533-537

Author(s):

Lorenz von Seidlein ◽

Borimas Hanboonkunupakarn ◽

Podjanee Jittmala ◽

Sasithon Pukrittayakamee

Keyword(s):

Protective Efficacy ◽

Age Groups ◽

Sub Saharan Africa ◽

Phase Iii ◽

European Medicines Agency ◽

Older Children ◽

Pivotal Phase ◽

Malaria Epidemiology ◽

Maximum Benefit ◽

Sub Saharan

RTS,S/AS01 is the most advanced vaccine to prevent malaria. It is safe and moderately effective. A large pivotal phase III trial in over 15 000 young children in sub-Saharan Africa completed in 2014 showed that the vaccine could protect around one-third of children (aged 5–17 months) and one-fourth of infants (aged 6–12 weeks) from uncomplicated falciparum malaria. The European Medicines Agency approved licensing and programmatic roll-out of the RTSS vaccine in malaria endemic countries in sub-Saharan Africa. WHO is planning further studies in a large Malaria Vaccine Implementation Programme, in more than 400 000 young African children. With the changing malaria epidemiology in Africa resulting in older children at risk, alternative modes of employment are under evaluation, for example the use of RTS,S/AS01 in older children as part of seasonal malaria prophylaxis. Another strategy is combining mass drug administrations with mass vaccine campaigns for all age groups in regional malaria elimination campaigns. A phase II trial is ongoing to evaluate the safety and immunogenicity of the RTSS in combination with antimalarial drugs in Thailand. Such novel approaches aim to extract the maximum benefit from the well-documented, short-lasting protective efficacy of RTS,S/AS01.

Download Full-text

Mortality and Society in Sub-Saharan Africa

Population Studies ◽

10.1080/0032472031000147416 ◽

1993 ◽

Vol 47 (3) ◽

pp. 555-556

Author(s):

Lado Ruzicka

Keyword(s):

Sub Saharan Africa ◽

Sub Saharan

Download Full-text

Sub-Saharan Africa

The Military Balance ◽

10.1080/04597228708459635 ◽

1987 ◽

Vol 87 (1) ◽

pp. 118-142

Keyword(s):

Sub Saharan Africa ◽

Sub Saharan

Download Full-text

Adolescent Suicidality as Seen in Rural Northeastern Uganda

Crisis ◽

10.1027/0227-5910/a000059 ◽

2011 ◽

Vol 32 (1) ◽

pp. 43-51 ◽

Cited By ~ 17

Author(s):

Eugene Kinyanda ◽

Ruth Kizza ◽

Jonathan Levin ◽

Sheila Ndyanabangi ◽

Catherine Abbo

Keyword(s):

Low Socioeconomic Status ◽

Sub Saharan Africa ◽

Psychosocial Risk ◽

Psychiatric Nurses ◽

Health Concern ◽

Cross Sectional ◽

Childhood Experiences ◽

Low Socioeconomic ◽

Dsm Iv ◽

Sub Saharan

Background: Suicidal behavior in adolescence is a public health concern and has serious consequences for adolescents and their families. There is, however, a paucity of data on this subject from sub-Saharan Africa, hence the need for this study. Aims: A cross-sectional multistage survey to investigate adolescent suicidality among other things was undertaken in rural northeastern Uganda. Methods: A structured protocol administered by trained psychiatric nurses collected information on sociodemographics, mental disorders (DSM-IV criteria), and psychological and psychosocial risk factors for children aged 3–19 years (N = 1492). For the purposes of this paper, an analysis of a subsample of adolescents (aged 10–19 years; n = 897) was undertaken. Results: Lifetime suicidality in this study was 6.1% (95% CI, 4.6%–7.9%). Conclusions: Factors significantly associated with suicidality included mental disorder, the ecological factor district of residence, factors suggestive of low socioeconomic status, and disadvantaged childhood experiences.

Download Full-text