Comparison and quantitative study of vulnerability/damage curves in South Africa

Southern Africa is considered a stable continental region in spite of several reported medium size earthquakes, some of which caused considerable damage and casualties. The 1969 Ceres 6.3 magnitude earthquake is considered the most destructive and caused serious damage estimated at US$24 million, with 12 mortalities and many more injured. Others include six mining related tremors which caused significant damage i.e. Welkom 1976, Klerksdorp 1977, Welkom 1989 and Carletonville 1992 seismic events. Notable for their damage to infrastructure was the 9th March 2005 Stilfontein event near Klerksdorp and 5th August 2014 event near Orkney. Most buildings and structures in South Africa are not designed to resist even relatively low intensity earthquake. Most architects, engineers and builders in South Africa do not consider seismic resistance as a design requirement. In this work, potential damage caused by strong earthquake was estimated for three classes of buildings situated in Sandton, Cape Town, Durban and Port Elizabeth. The effect of earthquakes causing damage was studied by considering the “worst case-scenario”, i.e. the occurrence of an earthquake with the maximum possible magnitude for an area. In four studied urban areas, expected damage was estimated for three classes of buildings: unreinforced masonry, bearing wall, low rise, reinforced concrete shear wall, without moment resisting frame, medium rise, and reinforced concrete shear wall, without moment resisting frame, high rise. The results of the analysis showed that in case of occurrence of a strong earthquake, the most damage is expected for the building classified as ‘unreinforced masonry, bearing wall, low rise, and reinforced concrete shear wall’.http://sajg.geoscienceworld.org/am2016Geolog

First recorded eruption of Nabro volcano, Eritrea, 2011

We present a synthesis of diverse observations of the first recorded eruption of Nabro volcano, Eritrea, which began on 12 June 2011. While no monitoring of the volcano was in effect at the time, it has been possible to reconstruct the nature and evolution of the eruption through analysis of re- gional seismological and infrasound data and satellite remote sensing data, supplemented by petrological analysis of erupted products and brief field surveys. The event is notable for the comparative rarity of recorded historical eruptions in the region and of caldera systems in general, for the prodi- gious quantity of SO2 emitted into the atmosphere and the significant human impacts that ensued notwithstanding the low population density of the Afar region. It is also relevant in understanding the broader magmatic and tectonic signifi- cance of the volcanic massif of which Nabro forms a part and which strikes obliquely to the principal rifting directions in the Red Sea and northern Afar. The whole-rock compositions of Editorial responsibility: G. Giordano the erupted lavas and tephra range from trachybasaltic to trachybasaltic andesite, and crystal-hosted melt inclusions contain up to 3,000 ppm of sulphur by weight. The eruption was preceded by significant seismicity, detected by regional networks of sensors and accompanied by sustained tremor. Substantial infrasound was recorded at distances of hundreds to thousands of kilometres from the vent, beginning at the onset of the eruption and continuing for weeks. Analysis of ground deformation suggests the eruption was fed by a shal- low, NW–SE-trending dike, which is consistent with field and satellite observations of vent distributions. Despite lack of prior planning and preparedness for volcanic events in the country, rapid coordination of the emergency response miti- gated the human costs of the eruption

Population structure of Salmonella enterica Typhi in Harare, Zimbabwe (2012–19) before typhoid conjugate vaccine roll-out: a genomic epidemiology study

\ua9 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: The continued emergence of Salmonella enterica serovar Typhi, with ever increasing antimicrobial resistance, necessitates the use of vaccines in endemic countries. A typhoid fever outbreak in Harare, Zimbabwe, in 2018 from a multidrug resistant S Typhi with additional resistance to ciprofloxacin was the catalyst for the introduction of a typhoid conjugate vaccine programme. We aimed to investigate the emergence and evolution of antimicrobial resistance of endemic S Typhi in Zimbabwe and to determine the population structure, gene flux, and sequence polymorphisms of strains isolated before a typhoid conjugate vaccine programme to provide a baseline for future evaluation of the effect of the vaccination programme. Methods: In this genomic epidemiology study, we used short-read whole-genome sequencing of S Typhi isolated from clinical cases of typhoid fever in Harare, Zimbabwe, between Jan 1, 2012, and Feb 9, 2019, to determine the S Typhi population structure, gene flux, and sequence polymorphisms and reconstructed the evolution of antimicrobial resistance. Maximum likelihood time-scaled phylogenetic trees of Zimbabwe isolates in the context of global isolates obtained from the National Center for Biotechnology Information were constructed to infer spread and emergence of antimicrobial resistance. Findings: The population structure of S Typhi in Harare, Zimbabwe, from 2012 to 2019 was dominated by multidrug resistant genotype 4.3.1.1.EA1 (H58) that spread to Zimbabwe from neighbouring countries in around 2009 (95% credible interval 2008\ub75–2010\ub70). Acquisition of an IncN plasmid carrying antimicrobial resistance genes including a qnrS gene and a mutation in the quinolone resistance determining region of gyrA gene contributed to non-susceptibility and resistance to quinolone antibiotics. A minority population of antimicrobial susceptible S Typhi genotype 3.3.1 strains were present throughout. Interpretation: The currently dominant S Typhi population is genotype 4.3.1.1 that spread to Zimbabwe and acquired additional antimicrobial resistance though acquisition of a plasmid and mutation in the gyrA gene. This study provides a baseline population structure for future evaluation of the effect of the typhoid conjugate vaccine programme in Harare. Funding: Bill & Melinda Gates Foundation and the Biotechnology and Biological Sciences Research Council Institute Strategic Programme

Regulatory and Activated T Cells in Human Schistosoma haematobium Infections

Acquired immunity against helminths is characterised by a complex interplay between the effector Th1 and Th2 immune responses and it slowly manifests with age as a result of cumulative exposure to parasite antigens. Data from experimental models suggest that immunity is also influenced by regulatory T cells (Treg), but as yet studies on Treg in human schistosome infections are limited

Population structure of Salmonella enterica Typhi in Harare, Zimbabwe (2012–19) before typhoid conjugate vaccine roll-out: A genomic epidemiology study

Background: The continued emergence of Salmonella enterica serovar Typhi, with ever increasing antimicrobial resistance, necessitates the use of vaccines in endemic countries. A typhoid fever outbreak in Harare, Zimbabwe, in 2018 from a multidrug resistant S Typhi with additional resistance to ciprofloxacin was the catalyst for the introduction of a typhoid conjugate vaccine programme. We aimed to investigate the emergence and evolution of antimicrobial resistance of endemic S Typhi in Zimbabwe and to determine the population structure, gene flux, and sequence polymorphisms of strains isolated before a typhoid conjugate vaccine programme to provide a baseline for future evaluation of the effect of the vaccination programme. Methods: In this genomic epidemiology study, we used short-read whole-genome sequencing of S Typhi isolated from clinical cases of typhoid fever in Harare, Zimbabwe, between Jan 1, 2012, and Feb 9, 2019, to determine the S Typhi population structure, gene flux, and sequence polymorphisms and reconstructed the evolution of antimicrobial resistance. Maximum likelihood time-scaled phylogenetic trees of Zimbabwe isolates in the context of global isolates obtained from the National Center for Biotechnology Information were constructed to infer spread and emergence of antimicrobial resistance. Findings: The population structure of S Typhi in Harare, Zimbabwe, from 2012 to 2019 was dominated by multidrug resistant genotype 4.3.1.1.EA1 (H58) that spread to Zimbabwe from neighbouring countries in around 2009 (95% credible interval 2008·5–2010·0). Acquisition of an IncN plasmid carrying antimicrobial resistance genes including a qnrS gene and a mutation in the quinolone resistance determining region of gyrA gene contributed to non-susceptibility and resistance to quinolone antibiotics. A minority population of antimicrobial susceptible S Typhi genotype 3.3.1 strains were present throughout. Interpretation: The currently dominant S Typhi population is genotype 4.3.1.1 that spread to Zimbabwe and acquired additional antimicrobial resistance though acquisition of a plasmid and mutation in the gyrA gene. This study provides a baseline population structure for future evaluation of the effect of the typhoid conjugate vaccine programme in Harare

Population structure of Salmonella enterica Typhi in Harare, Zimbabwe (2012-19) before typhoid conjugate vaccine roll-out : a genomic epidemiology study

DATA SHARING : All sequence data are freely available from the Short Read Archive of the National Center for Biotechnology Information under accession numbers listed in the appendix (pp 12–63). Sample metadata are summarised in the appendix (pp 12–63).BACKGROUND : The continued emergence of Salmonella enterica serovar Typhi, with ever increasing antimicrobial resistance, necessitates the use of vaccines in endemic countries. A typhoid fever outbreak in Harare, Zimbabwe, in 2018 from a multidrug resistant S Typhi with additional resistance to ciprofloxacin was the catalyst for the introduction of a typhoid conjugate vaccine programme. We aimed to investigate the emergence and evolution of antimicrobial resistance of endemic S Typhi in Zimbabwe and to determine the population structure, gene flux, and sequence polymorphisms of strains isolated before a typhoid conjugate vaccine programme to provide a baseline for future evaluation of the effect of the vaccination programme. METHODS : In this genomic epidemiology study, we used short-read whole-genome sequencing of S Typhi isolated from clinical cases of typhoid fever in Harare, Zimbabwe, between Jan 1, 2012, and Feb 9, 2019, to determine the S Typhi population structure, gene flux, and sequence polymorphisms and reconstructed the evolution of antimicrobial resistance. Maximum likelihood time-scaled phylogenetic trees of Zimbabwe isolates in the context of global isolates obtained from the National Center for Biotechnology Information were constructed to infer spread and emergence of antimicrobial resistance. FINDINGS : The population structure of S Typhi in Harare, Zimbabwe, from 2012 to 2019 was dominated by multidrug resistant genotype 4.3.1.1.EA1 (H58) that spread to Zimbabwe from neighbouring countries in around 2009 (95% credible interval 2008·5–2010·0). Acquisition of an IncN plasmid carrying antimicrobial resistance genes including a qnrS gene and a mutation in the quinolone resistance determining region of gyrA gene contributed to non-susceptibility and resistance to quinolone antibiotics. A minority population of antimicrobial susceptible S Typhi genotype 3.3.1 strains were present throughout. INTERPRETATION : The currently dominant S Typhi population is genotype 4.3.1.1 that spread to Zimbabwe and acquired additional antimicrobial resistance though acquisition of a plasmid and mutation in the gyrA gene. This study provides a baseline population structure for future evaluation of the effect of the typhoid conjugate vaccine programme in Harare.The Bill & Melinda Gates Foundation and the Biotechnology and Biological Sciences Research Council Institute Strategic Programme.http://www.thelancet.com/microbeam2024Medical MicrobiologySDG-03:Good heatlh and well-bein

Impact of COVID-19 on healthcare programs in Zimbabwe: a mixed methods study

Abstract Background The COVID-19 pandemic disrupted healthcare services. Understanding similar epidemic-related disruptions on a broader scope in our local setting is critical for the effective planning of essential services. The study determined the impact of Coronavirus disease(COVID-19) on healthcare programs in Zimbabwe. Methods A mixed-methods study compared healthcare service delivery trends from the Ministry of Health and Child Care before, during and post the pandemic. It employed two methods of data collection: Key informant interviews (KII) and secondary data analysis from the Zimbabwe District Health Information Systems 2 (DHIS2). Purposive sampling obtained key informants for interviews whilst 18 healthcare service indicators were identified from the national database. Statistical analysis consisted of an interrupted time series analysis of those indicators preceded by visualization to appreciate trend change. An inductive approach was used to code and identify basic themes which were then triangulated against DHIS2 findings. Results The study revealed that COVID-19 had a negative impact on health service delivery; increasing disruptions of critical healthcare services, maternal and child health, reproductive health issues, and other specialist services were prominent. The rise in maternal and child mortality cases and caesarean sections could be directly linked to the decline in service delivery during the pandemic. Mitigation strategies that were introduced during the pandemic included the use of community-based services, outreach services, capacity building, and de-congestion of public services. Conclusions The pandemic disrupted healthcare delivery, causing service usage to decline due to lockdowns. Response strategies included community services, capacity building, and stakeholder engagement. Future readiness requires epidemic plans, enhanced resources, a multisectoral approach, workforce training, and public education

CD16 Expression on Monocytes in Healthy Individuals but Not Schistosome-Infected Patients Is Positively Associated with Levels of Parasite-Specific IgG and IgG1

Human IgG1 antibody responses are associated with protection against Schistosoma haematobium infection and are now a target for schistosome vaccine development. This study aimed to investigate the relationship between total IgG and the IgG subclasses and the monocyte IgG receptor, known as FcγRIIIa or CD16, in schistosome exposed people. Systemic levels of schistosome-specific anti-adult worm total IgG and IgG subclass titres were measured by ELISA in 100 individuals from an S. haematobium endemic area in Zimbabwe and, using parametric statistical methods and regression analysis, related to the levels of CD16 expression on individuals' circulating monocytes, determined via flow cytometry. Monocyte CD16 expression rose with parasite-specific total IgG and IgG1 in healthy participants, but not in schistosome infected patients. Similar to parasite-specific IgG and IgG1, CD16 expression in healthy individuals is associated with protection against schistosome infection. This relationship indicates a mechanistic link between the innate and adaptive immune responses to helminth infection in protection against infection. Further understanding the elements of a protective immune response in schistosomiasis may aid in efforts to develop a protective vaccine against this disease.This work was supported by the World Health Organisation and the Wellcome Trust grant WT082028MA, the Thrasher Research Fund and the Medical Research Council grant LJA-544