EVALUATION DES ACTIVITÉS ANTIMICROBIENNES DE TRIDAX PROCUMBENS (ASTERACEAE), JATROPHA MULTIFIDA (EUPHORBIACEAE) ET DE CHROMOLAENA ODORATA (ASTERACEAE)

Tridax procumbens, Jatropha multifida and Chromolaena odorata are three ( 03) plants used in traditional medicine for treatment of some of the most common diseases in Togo . These plants have been studied for their antibacterial and antifungal activities. To this end, ethanolic and aqueous extracts of these plants were tested by the method of broth dilution coupled with the spreading on solid medium. The antimicrobial activity of three plants was assessed on three germs two bacteria (Staphylococcus aureus and Escherichia coli) and yeast (Candida albicans). The results showed that J. multifida has a very strong inhibitory activity against C. albicans (nearly 100 %) and moderate activity on both bacteria. The three extracts of root bark of C. odorata have a significant effect on S. aureus and E. coli and lower action on C. albicans. Extracts from the leaves of T. procumbens inhibited S. aureus growing in about 98 % and E. coli to nearly 70 %. It’s activity against C. albicans is average. A basic phytochemical analysis of these extracts helped highlight tannins, flavonoids, alkaloids in the extracts of all the tested plants. These compounds would be the cause of their inhibitory effects

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Epidemiological and virological surveillance of the prevention of mother-to-child transmission of HIV among pregnant women in Togo

Summary Background In 2015, Togo introduced the “test-and-treat” strategy for the prevention of mother-to-child transmission (PMTCT) of HIV. Pediatric HIV infection remains a public health problem in Togo, with a mother-to-child transmission (MTCT) rate of 3.6% in 2020. This study aimed to estimate cases of HIV seroconversion during pregnancy and to identify pregnant women at high risk of transmitting HIV to their children in Lomé, Togo. Methods A descriptive cross-sectional study was carried out from 18 March to 22 May 2022 among women who had given birth in five maternity units providing PMTCT services in Lomé. Umbilical cord blood samples were taken from the maternal side by midwives after delivery. HIV serology was performed in the laboratory using the Alere™ HIV Combo SET and First Response HIV 1–2. Card Test version 2.0. A sample was considered positive if both tests were positive. The HIV-1 viral load in HIV-1-positive samples was measured using Cobas/Roche 4800 equipment. Information on the women was extracted from maternal antenatal records and antenatal consultation registers. Results A total of 3148 umbilical cord blood samples (median maternal age: 28 years (interquartile range [24–32]) were collected. Among them, 99.3% (3145/3148) had presented for at least one antenatal clinic visit before giving birth, and 78.7% (2456/3122) had presented for at least four visits. One hundred and twenty-one (121) cord samples were HIV-1 positive, representing a seroprevalence of 3.8% (95% CI = [3.2–4.6]). Among them, 67.8% (82/121) were known HIV-positive before the current pregnancy, 29.7 (36/121) were diagnosed as HIV-positive at the antenatal visits and 2.5% (3/121) were diagnosed as HIV-positive in the delivery room. Of the HIV-positive women, 85.9% (104/121) were on ARV treatment before delivery. The viral load was < 1000 copies/ml in 97.5% (118/121) cases. Conclusion This study explored the virologic and epidemiological aspects of HIV among pregnant women in Togo. The results show significant viral suppression at delivery in women ART. Surveillance based on umbilical cord blood specimen screening is an interesting approach for monitoring the effectiveness of PMTCT programmes