Zero malaria: a mirage or reality for populations of sub-Saharan Africa in health transition.

The global burden of malaria continues to be a significant public health concern. Despite advances made in therapeutics for malaria, there continues to be high morbidity and mortality associated with this infectious disease. Sub-Saharan Africa continues to be the most affected by the disease, but unfortunately the region is burdened with indigent health systems. With the recent increase in lifestyle diseases, the region is currently in a health transition, complicating the situation by posing a double challenge to the already ailing health sector. In answer to the continuous challenge of malaria, the African Union has started a "zero malaria starts with me" campaign that seeks to personalize malaria prevention and bring it down to the grass-root level. This review discusses the contribution of sub-Saharan Africa, whose population is in a health transition, to malaria elimination. In addition, the review explores the challenges that health systems in these countries face, that may hinder the attainment of a zero-malaria goal.

Profiling the Quality and Quantity of Naturally Induced Antibody Responses Against Pfs230 and Pfs48/45 Among Non-Febrile Children Living in Southern Ghana: A Longitudinal Study.

A clear understanding of the properties of naturally induced antibody responses against transmission-blocking vaccine candidates can accelerate the understanding of the development of transmission-blocking immunity. This study characterized the naturally induced IgG responses against two leading transmission-blocking vaccine antigens, Pfs230 and Pfs48/45, in non-febrile children living in Simiw, Ghana. Consecutive sampling was used to recruit 84 non-febrile children aged from 6 to 12 years old into the 6-month (November 2017 until May 2018) longitudinal study. Venous blood (1 ml) was collected once every 2 months and used to determine hemoglobin levels, P. falciparum prevalence using microscopy and polymerase chain reaction, and the levels and relative avidity of IgG responses against Pfs230 and Pfs48/45 using indirect ELISA. IgG levels against Pfs230 and Pfs48/45 decreased from the start (November) to the middle (January) and end (March) of the dry season respectively, then they began to increase. Participants, especially older children (10-12 years old) with active infections generally had lower antibody levels against both antigens. The relative avidities of IgG against both antigens followed the trend of IgG levels until the middle of the dry season, after which the relative avidities of both antigens correlated inversely with the antibody levels. In conclusion, although IgG antibody levels against both Pfs48/45 and Pfs230 began to increase by the early rainy season, they were inversely correlated to their respective relative avidities.

Persistent Plasmodium falciparum infections enhance transmission-reducing immunity development.

Subclinical infections that serve as reservoir populations to drive transmission remain a hurdle to malaria control. Data on infection dynamics in a geographical area is required to strategically design and implement malaria interventions. In a longitudinal cohort, we monitored Plasmodium falciparum infection prevalence and persistence, and anti-parasite immunity to gametocyte and asexual antigens for 10 weeks. Of the 100 participants, only 11 were never infected, whilst 16 had persistent infections detected by reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR), and one participant had microscopic parasites at all visits. Over 70% of the participants were infected three or more times, and submicroscopic gametocyte prevalence was high, ≥ 48% of the parasite carriers. Naturally induced responses against recombinant Pfs48/45.6C, Pfs230proC, and EBA175RIII-V antigens were not associated with either infection status or gametocyte carriage, but the antigen-specific IgG titers inversely correlated with parasite and gametocyte densities consistent with partial immunity. Longitudinal analysis of gametocyte diversity indicated at least four distinct clones circulated throughout the study period. The high prevalence of children infected with distinct gametocyte clones coupled with marked variation in infection status at the individual level suggests ongoing transmission and should be targeted in malaria control programs.

Molecular epidemiology of Mycobacterium africanum in Ghana.

BACKGROUND: Mycobacterium africanum comprises two phylogenetic lineages within the M. tuberculosis complex (MTBC) and is an important cause of human tuberculosis (TB) in West Africa. The reasons for this geographic restriction of M. africanum remain unclear. Here, we performed a prospective study to explore associations between the characteristics of TB patients and the MTBC lineages circulating in Ghana. METHOD: We genotyped 1,211 MTBC isolates recovered from pulmonary TB patients recruited between 2012 and 2014 using single nucleotide polymorphism typing and spoligotyping. Associations between patient and pathogen variables were assessed using univariate and multivariate logistic regression. RESULTS: Of the 1,211 MTBC isolates analysed, 71.9 % (871) belonged to Lineage 4; 12.6 % (152) to Lineage 5 (also known as M. africanum West-Africa 1), 9.2 % (112) to Lineage 6 (also known as M. africanum West-Africa 2) and 0.6 % (7) to Mycobacterium bovis. Univariate analysis revealed that Lineage 6 strains were less likely to be isoniazid resistant compared to other strains (odds ratio = 0.25, 95 % confidence interval (CI): 0.05-0.77, P < 0.01). Multivariate analysis showed that Lineage 5 was significantly more common in patients from the Ewe ethnic group (adjusted odds ratio (adjOR): 2.79; 95 % CI: 1.47-5.29, P < 0.001) and Lineage 6 more likely to be found among HIV-co-infected TB patients (adjOR = 2.2; 95 % confidence interval (CI: 1.32-3.7, P < 0.001). CONCLUSION: Our findings confirm the importance of M. africanum in Ghana and highlight the need to differentiate between Lineage 5 and Lineage 6, as these lineages differ in associated patient variables.

Disregard of neurological impairments associated with neglected tropical diseases in Africa.

Neglected tropical diseases (NTDs) affect people in the bottom billion poorest in the world. These diseases are concentrated in rural areas, conflict zones and urban slums in Africa and other tropical areas. While the World Health Organization recognizes seventeen priority NTDs, the list of conditions present in Africa and elsewhere that are eligible to be classified as NTDs is much longer. Although NTDs are generally marginalized, their associated neurological burden has been almost completely disregarded. However, reports indicate that trichuriasis, schistosomiasis and hookworm infection, among others, cause impairments in memory and cognition, negatively affecting school attendance rates and educational performance particularly among children, as well as agricultural productivity among adults. Consequently, the neurological impairments have substantial influence on education and economic productivity, thus aggravating and perpetuating poverty in affected societies. However, inadequate research, policy and public health attention has been paid to the neurological burdens associated with NTDs. In order to appropriately address these burdens, we recommend the development of policy interventions that focus on the following areas: (i) the introduction of training programs to develop the capacity of scientists and clinicians in research, diagnostic and treatment approaches (ii) the establishment of competitive research grant schemes to fund cutting-edge research into these neurological impairments, and (iii) the development of public health interventions to improve community awareness of the NTD-associated neurological problems, possibly enhancing disease prevention and expediting treatment.