Investment in SARS-CoV-2 sequencing in Africa over the past year has led to a major increase in the number of sequences generated, now exceeding 100,000 genomes, used to track the pandemic on the continent. Our results show an increase in the number of African countries able to sequence domestically, and highlight that local sequencing enables faster turnaround time and more regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and shed light on the distinct dispersal dynamics of Variants of Concern, particularly Alpha, Beta, Delta, and Omicron, on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve, while the continent faces many emerging and re-emerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century.

BackgroundImpact of the pathophysiology of Plasmodium falciparum placental malaria (PM) on the profile of some oxidative stress biomarkers and their relationship with poor pregnancy outcomes in women remain unknown.MethodsBetween 2013 and 2014, peripheral blood and placenta tissue from 120 Cameroonian women at delivery were assessed for maternal haemoglobin and, parasitaemia respectively. Parasite accumulation in the placenta was investigated histologically. The levels of oxidative stress biomarkers Malondialdehyde (MDA), Nitric Oxide (NO), Superoxide dismutase (SOD), Catalase (CAT) and Gluthatione (GSH) in the supernatant of teased placenta tissues were determined by Colorimetric enzymatic assays.ResultsParasitaemia was inversely related to haemoglobin levels and birth weight (P <0.001 and 0.012, respectively). The level of lipid peroxide product (MDA) was significantly higher in the malaria infected (P = 0.0047) and anaemic (P = 0.024) women compared to their non-infected and non-anaemic counterparts, respectively. A similar trend was observed with SOD levels, though not significant. The levels of MDA also correlated positively with parasitaemia (P = 0.0024) but negatively with haemoglobin levels (P = 0.002). There was no association between parasitaemia, haemoglobin level and the other oxidative stress biomarkers. From histological studies, levels of MDA associated positively and significantly with placenta malaria infection and the presence of malaria pigments. The levels of SOD, NO and CAT increased with decreasing leukocyte accumulation in the intervillous space. Baby birth weight increased significantly with SOD and CAT levels, but decreased with levels of GSH.ConclusionsPlacental P. falciparum infection may cause oxidative stress of the placenta tissue with MDA as a potential biomarker of PM, which alongside GSH could lead to poor pregnancy outcomes (anaemia and low birth weight). This finding contributes to the understanding of the pathophysiology of P. falciparum placental malaria in women.

Although Th17 cells subsets improve immunity against extra and intracellular pathogens, and in modulating Th1 and other immune responses, its role on pregnancy‐associated malaria (PAM) is unknown. This study aims to investigate the effects of PAM on Th1 (IFN‐γ, TNF‐α), IL‐10 family (IL‐10, IL‐19, IL‐22), Th17 (IL‐17A, IL‐23) cytokines and on CXCL‐10 chemokine profiles in pregnant women. Between 2010 and 2011, venous blood specimens from 107 volunteer pregnant Cameroonian women was used to determine parasitaemia microscopically and haemoglobin levels using HemoCue analyzer. Plasma levels of the biomarkers were determined by ELISA. Parasitaemia was higher in women with low haemoglobin levels, parity and mother's age. IL‐10 and CXCL‐10 plasma levels were higher in the malaria infected and in anaemic women while IFN‐γ and IL‐17A levels were higher in malaria non‐infected and in non‐anaemic women. Parasitaemia correlated positively with IL‐10 and CXCL‐10 levels but inversely with IFN‐γ and IL‐17A. Haemoglobin levels were higher in women with low IL‐10 and CXCL‐10 levels, and in group with high IFN‐γ, IL‐17A and IL‐23 levels. Only IL‐10 levels associated negatively with parity. Positive correlations were observed between Th17 (IL‐17A) and Th1 (IFN‐γ, TNF‐α), IL‐10 family (IL‐19 and IL‐22) and Th17 (IL‐23) cytokines. Multivariate analysis showed association between: mother's age and IFN‐γ levels, parasitaemia and IL‐10 and CXCL‐10 levels and haemoglobin levels, gestational age and IL‐17A levels. In conclusion, during PAM, CXCL‐10 and IL‐10 responses are implicated in the pathogenesis while Th17 and Th1 immune responses, via IL‐17A and IFN‐γ might play protective roles.

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