Sickle Cell Disease in East African Countries: Prevalence, Complications and Management

Sickle cell disease (SCD) is one of the most common life-threatening monogenic disorders affecting millions of people worldwide. The disease has a high prevalence in malaria-endemic tropics, especially in sub-Saharan Africa. Although sickle-cell trait (SCT) offers protective advantage against malaria, it does not apply to homozygous individuals with sickle cell anemia but instead makes them more susceptible to not only malaria but to also other infections, causing a great deal of under-five mortality. Despite the fatal risks and high incidence rates of SCD, little attention is given, in terms of funding, management and surveillance, especially among East African countries. In addition, few works of literature exist, and less has been documented about the disease. This minireview aimed to report the current situation in terms of prevalence, mortality, diagnosis and management of SCD among East African countries; Uganda, Kenya, Tanzania, Rwanda and Burundi SCD is characterised by retarded growth, chronic pain attacks and severe organ damage leading to fatal complications. This, coupled with limited resources in East African countries, reduces the survival of SCD patients and most die before five years. SCD is detected through a blood test usually by Haemoglobin electrophoresis, and Hydroxyurea therapy, antibiotics and blood transfusion are used to prevent complications. Early childhood detection through comprehensive newborn screening programmes has been implementedin some countries and is key in the management of the disease.

Low topotype diversity of recent foot-and-mouth disease virus serotypes O and A from districts located along the Uganda and Tanzania border

Foot-and-mouth disease (FMD) is one of the most important livestock diseases in East Africa with outbreaks reported annually that cause severe economic losses. It is possible to control disease using vaccination, but antigenic matching of the vaccine to circulating strains is critical. To determine the relationship between foot-and-mouth disease viruses circulating in districts along the Uganda and Tanzanian border between 2016 and 2017 and currently used vaccines, phylogenetic analysis of the full VP1 virus sequences was carried out on samples collected from both sides of the border. A total of 43 clinical samples were collected from animals exhibiting signs of FMD and VP1 sequences generated from 11 of them. Eight out of the 11 sequences obtained belonged to serotype O and three belonged to serotype A. The serotype O sequences obtained showed limited nucleotide divergence (average of 4.9%) and belonged to topotype East Africa-2, whereas the most common O-type vaccine strain used in the region (O/KEN/77/78) belonged to East Africa-1. The serotype A viruses belonged to topotype Africa-G1 (average nucleotide divergence 7.4%), as did vaccine strain K5/1980. However, vaccine strain K35/1980 belonged to Africa G VII with an average sequence divergence of 20.5% from the study sequences. The genetic distances between current vaccine strains and circulating field strains underscores the crucial need for regular vaccine matching and the importance of collaborative efforts for better control of FMD along this border area.

Occurrence of Bondar's Nesting Whitefly, Paraleyrodes bondari (Hemiptera: Aleyrodidae), on cassava in Uganda

ABSTRACT Cassava is a valued calorific source to millions of Africans who eat it daily and a vital staple for their food security. One of the key constraints to this crop is whiteflies which are both a vector of viral diseases and a direct pest. Although the African cassava whitefly is known to cause physical damage on cassava with considerable tuberous yield loss, a recent whitefly outbreak caused unusually severe damage, which prompted the current reported investigation. Molecular identification of whitefly adults sampled from the affected cassava field revealed the presence of a new whitefly species, Paraleyrodes bondari. This communication is the first report of the occurrence of P. bondari on cassava in Uganda.