Treatment of shigella infections: why sulfamethoxazole-trimethoprim, tetracyclines and ampicillin should no longer be used

Background: Bloody diarrhoea results in high morbidity and mortality especially in developing countries with shigellosis being the main cause of acute bloody diarrhoea. The use of appropriate antimicrobial agents in the treatment of acute diarrheal disease shortens the duration of illness and bacterial shedding leading to a reduction in morbidity and mortality. Treatment options for many infections are becoming limited due to globally emerging antibiotic resistance. Globally, resistance of shigella species to trimethoprim-sulfamethoxazole (TMP-SMX), tetracyclines and ampicillin has been reported with subsequent recommendations of not using these antimicrobial drugs for empirical therapy of acute bloody diarrhoea.Objective: To establish the antimicrobial susceptibility patterns and antimicrobial drug use for treatment of shigella species in patients with acute bloody diarrhoea.Design: A hospital based case control study.Setting: Six health facilities, three in Kilifi County and three in Nairobi County.Subject: A total of 284 stool specimens were collected from patients who fitted the standard cases definition for acute bloody diarrhoea.Results: Eighty (28.2%) bacterial isolates were recovered from 284 stool samples collected from cases presenting with acute bloody diarrhoea of which 67 (83.8%) were Shigella species, nine (11.3%) were Enteroinvassive Escherichia coli isolates, three (3.8%) were Salmonella Typhi and one (1.3%) were Yersinia enterocolitica. Shigella isolates had high resistance to sulfamethoxazole-trimethoprim (97%), tetracycline (83.6%) ampicillin (58.2%) and chloramphenicol (20.9%). The isolates showed low resistance to nalidixic (4.5%) and ciprofloxacin (3.0%) while there was no resistance to ceftriaxone. The most common multidrug resistance pattern detected in Shigella strains combined sulfamethoxazole-trimethoprim, amoxicillin/ampicillin and tetracyclines.Antibiotic prescriptions were given to 243(85.6%) of the patients presenting with acute bloody diarrhoea. Among these, 94 (38.7%) were given prescriptions for ciprofloxacin, 53 (21.8%) for sulfamethaxazole-trimethiprin and 36(14.8%) for Tetracyclines. Chloramphenicol, amoxicillin/ampicillin, nalidixic acid and ceftriaxone were prescribed to 10.7 %, 3.7%, 2.9% and 0.4% of the patients respectively. A total of 123 (51%) received antibiotics which were ranked to have high resistance (sulfamethoxazole-trimethoprim, tetracyclines ampicillin and chloramphenicol).Conclusion: The high rates of antimicrobial resistance among the commonly prescribed antimicrobials such as sulfamethoxazole-trimethoprim, tetracycline, ampicillin and chloramphenicol is of major concern. Despite recommendations discouraging the empirical use of sulfamethoxazole-trimethoprim, tetracycline, ampicillin and chloramphenicol for treatment of acute bloody diarrhoea, more than half of the patients with acute bloody diarrhoea were still treated with these antibiotics.There is need to train health care workers on the proper management of acute bloody diarrhoea and the importance of adhering to the clinical guidelines

Development and characterization of epoxy nanocomposites based on nano-structured oil palm ash.

The aim of this study is to utilize the bio-agricultural waste as filler material for composite production which are abundantly available and low cost compared to the silica, alumina etc. The lacks of sufficient scientific information about the utilization of the oil palm ash (OPA) on composites production were the driving force for the choice of this work. Furthermore, the effect of filler loading percentage on physical, mechanical, thermal and morphology properties of the epoxy nanocomposites were studied. It was concluded that the size of the OPA had been successfully reduced from macromolecular to the nano-size range by high energy ball milling and was confirmed by TEM analysis. The density of the nano-structured OPA filled epoxy composites revealed that increasing filler loading will eventually increase the density. The tensile and flexural strength attained maximum value when the filler loading was 3%. Also, increase in the thermal stability was observed in case of 3% filler loading and was attributed to the increase in cross-linking of the epoxy resin in the presence of nano-stuctured OPA and having minimum particle to particle interaction and well dispersed nanoparticles

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