Utilizing river and wastewater as a SARS-CoV-2 surveillance tool in settings with limited formal sewage systems.

The COVID-19 pandemic has profoundly impacted health systems globally and robust surveillance has been critical for pandemic control, however not all countries can currently sustain community pathogen surveillance programs. Wastewater surveillance has proven valuable in high-income settings, but less is known about the utility of water surveillance of pathogens in low-income countries. Here we show how wastewater surveillance of SAR-CoV-2 can be used to identify temporal changes and help determine circulating variants quickly.

Household costs and care seeking patterns associated with COVID-19 in Blantyre, Malawi.

Economic consequences of COVID-19 illness and healthcare use for households in low income countries are not well known. We estimated costs associated with COVID-19 care-seeking and treatment from a household perspective and assessed determinants of treatment costs. A cross-sectional household survey was conducted between December 2020 and November 2021 in urban and peri-urban areas of Blantyre district.

Nontyphoidal Invasive Disease: Challenges and Solutions.

Nontyphoidal are a leading cause of community-onset bacteremia and other serious infections in sub-Saharan African countries where large studies indicate that they are an uncommon cause of moderate-to-severe diarrhea. Approximately 535 000 nontyphoidal invasive disease illnesses and 77 500 deaths were estimated to occur in 2017; 422 000 (78.9%) illnesses and 66 500 (85.

Intracellular survival of in human alveolar macrophages is augmented with HIV infection.

People Living with HIV (PLHIV) are at an increased risk of pneumococcal pneumonia than HIV-uninfected adults, but the reasons for this are still not well understood. We investigated whether alveolar macrophages (AM) mediated control of pneumococcal infection is impaired in PLHIV compared to HIV-uninfected adults. We assessed anti-bactericidal activity against of primary human AM obtained from PLHIV and HIV-uninfected adults.

Antimicrobial susceptibility testing profiles of ESBL-producing isolated from hospital and community adult patients in Blantyre, Malawi.

Objective: There is a paucity of data on antimicrobial resistance (AMR) in Malawi. Here we present a study of AMR of extended-spectrum β-lactamases-producing (ESBL-E) isolated from hospital and community settings in Blantyre, Malawi.

Design And Methods: A cross-sectional study was conducted between March and November 2020, involving 403 adult participants aged ≥18 years.

Validation of a direct-to-PCR COVID-19 detection protocol utilizing mechanical homogenization: A model for reducing resources needed for accurate testing.

Efficient and effective viral detection methodologies are a critical piece in the global response to COVID-19, with PCR-based nasopharyngeal and oropharyngeal swab testing serving as the current gold standard. With over 100 million confirmed cases globally, the supply chains supporting these PCR testing efforts are under a tremendous amount of stress, driving the need for innovative and accurate diagnostic solutions. Herein, the utility of a direct-to-PCR method of SARS-CoV-2 detection grounded in mechanical homogenization is examined for reducing resources needed for testing while maintaining a comparable sensitivity to the current gold standard workflow of nasopharyngeal and oropharyngeal swab testing.

Performance of molecular methods for the detection of in human stool specimens.

The relationship between asymptomatic exposure within the gastrointestinal tract and bacteraemia is poorly understood, in part due to the low sensitivity of stool culture and the lack of validated molecular diagnostic tests for the detection of in the stool. The study aimed to determine a reliable molecular diagnostic test for in stool specimens. We optimised an in-house monoplex real-time polymerase chain reaction (PCR) for the detection of and genes in stool by including a selenite broth pre-culture step for before DNA extraction and validated their specificity against other local common pathogens.

Evasion of MAIT cell recognition by the African Typhimurium ST313 pathovar that causes invasive disease.

Mucosal-associated invariant T (MAIT) cells are innate T lymphocytes activated by bacteria that produce vitamin B2 metabolites. Mouse models of infection have demonstrated a role for MAIT cells in antimicrobial defense. However, proposed protective roles of MAIT cells in human infections remain unproven and clinical conditions associated with selective absence of MAIT cells have not been identified.

Plasma cell-free DNA predicts pediatric cerebral malaria severity.

BACKGROUNDPrediction of adverse outcomes in cerebral malaria (CM) is difficult. We hypothesized that cell-free DNA (cfDNA) levels would facilitate identification of severe and potentially fatal CM cases.METHODSIn this retrospective study, plasma from Malawian children with CM (n = 134), uncomplicated malaria (UM, n = 77), and healthy controls (HC, n = 60) was assayed for cfDNA using a fluorescence assay.

Distinct Biomarker Profiles Distinguish Malawian Children with Malarial and Non-malarial Sepsis.

Presently, it is difficult to accurately diagnose sepsis, a common cause of childhood death in sub-Saharan Africa, in malaria-endemic areas, given the clinical and pathophysiological overlap between malarial and non-malarial sepsis. Host biomarkers can distinguish sepsis from uncomplicated fever, but are often abnormal in malaria in the absence of sepsis. To identify biomarkers that predict sepsis in a malaria-endemic setting, we retrospectively analyzed data and sera from a case-control study of febrile Malawian children (aged 6-60 months) with and without malaria who presented to a community health center in Blantyre (January-August 2016).

Ascertaining the burden of invasive Salmonella disease in hospitalised febrile children aged under four years in Blantyre, Malawi.

Typhoid fever is endemic across sub-Saharan Africa. However, estimates of the burden of typhoid are undermined by insufficient blood volumes and lack of sensitivity of blood culture. Here, we aimed to address this limitation by exploiting pre-enrichment culture followed by PCR, alongside routine blood culture to improve typhoid case detection.

HIV infection has a profound effect on hematological factors but not on electrolyte profile of Malawian adults presenting with uncomplicated malaria and severe malaria.

Aim: Although malaria and HIV infections independently affect the electrolyte and hematologic profiles, little is known of how these profiles are affected in individuals coinfected with malaria and HIV. We therefore conducted this study to investigate the electrolyte and hematologic profiles of Malawian adults presenting with either uncomplicated malaria (UM), severe malaria (SM), and those presenting with HIV and UM or HIV and SM.

Methods: Study participants were recruited at Queen Elizabeth Central Hospital, and malaria infection was confirmed by rapid diagnostic test and malaria slides, and full blood count, HIV, and wet chemistries were analyzed.

Longevity of duodenal and peripheral T-cell and humoral responses to live-attenuated Salmonella Typhi strain Ty21a.

Background: We have previously demonstrated that polyfunctional Ty21a-responsive CD4 and CD8 T cells are generated at the duodenal mucosa 18 days following vaccination with live-attenuated S. Typhi (Ty21a). The longevity of cellular responses has been assessed in peripheral blood, but persistence of duodenal responses is unknown.

Immunological bases of increased susceptibility to invasive nontyphoidal Salmonella infection in children with malaria and anaemia.

Malaria and anaemia are key underlying factors for iNTS disease in African children. Knowledge of clinical and epidemiological risk-factors for iNTS disease has not been paralleled by an in-depth knowledge of the immunobiology of the disease. Herein, we review human and animal studies on mechanisms of increased susceptibility to iNTS in children.

T-Regulatory Cells and Inflammatory and Inhibitory Cytokines in Malawian Children Residing in an Area of High and an Area of Low Malaria Transmission During Acute Uncomplicated Malaria and in Convalescence.

Background: Malaria still infects many Malawian children, and it is a cause of death in some of them. Regulatory T cells (Tregs) help in negating immune-related pathology, it but can also favor multiplication of malaria parasites. The question remains whether children recovering from uncomplicated malaria (UCM) have higher Tregs and interleukin (IL)-10 levels in convalescence.

Sequential acquisition of T cells and antibodies to nontyphoidal Salmonella in Malawian children.

Background: Salmonella Typhimurium (STm) remain a prominent cause of bacteremia in sub-Saharan Africa. Complement-fixing antibodies to STm develop by 2 years of age. We hypothesized that STm-specific CD4⁺ T cells develop alongside this process.

Early interferon-γ production in human lymphocyte subsets in response to nontyphoidal Salmonella demonstrates inherent capacity in innate cells.

Background: Nontyphoidal Salmonellae frequently cause life-threatening bacteremia in sub-Saharan Africa. Young children and HIV-infected adults are particularly susceptible. High case-fatality rates and increasing antibiotic resistance require new approaches to the management of this disease.