Evaluation of the burden of unsuspected pulmonary tuberculosis and co-morbidity with non-communicable diseases in sputum producing adult inpatients

A high burden of tuberculosis (TB) occurs in sub-Saharan African countries and many cases of active TB and drug-resistant TB remain undiagnosed. Tertiary care hospitals provide an opportunity to study TB co-morbidity with non-communicable and other communicable diseases (NCDs/CDs). We evaluated the burden of undiagnosed pulmonary TB and multi-drug resistant TB in adult inpatients, regardless of their primary admission diagnosis, in a tertiary referral centre. In this prospective study, newly admitted adult inpatients able to produce sputum at the University Teaching Hospital, Lusaka, Zambia, were screened for pulmonary TB using fluorescent smear microscopy and automated liquid culture. The burden of pulmonary TB, unsuspected TB, TB co-morbidity with NCDs and CDs was determined. Sputum was analysed from 900 inpatients (70.6% HIV infected) 277 (30.8%) non-TB suspects, 286 (31.8%) TB suspects and 337 (37.4%) were already receiving TB treatment. 202/900 (22.4%) of patients had culture confirmed TB. TB co-morbidity was detected in 20/275 (7.3%) NCD patients, significantly associated with diabetes (P = 0.006, OR 6.571, 95%CI: 1.706-25.3). 27/202 (13.4%) TB cases were unsuspected. There were 18 confirmed cases of MDR-TB, 5 of which were unsuspected. A large burden of unsuspected pulmonary TB co-morbidity exists in inpatients with NCDs and other CDs. Pro-active sputum screening of all inpatients in tertiary referral centres in high TB endemic countries is recommended. The scale of the problem of undiagnosed MDR-TB in inpatients requires further study

Burden of respiratory tract infections at post mortem in Zambian children

Background: Autopsy studies are the gold standard for determining cause-of-death and can inform on improved diagnostic strategies and algorithms to improve patient care. We conducted a cross-sectional observational autopsy study to describe the burden of respiratory tract infections in inpatient children who died at the University Teaching Hospital in Lusaka, Zambia. Methods: Gross pathology was recorded and lung tissue was analysed by histopathology and molecular diagnostics. Recruitment bias was estimated by comparing recruited and non-recruited cases. Results: Of 121 children autopsied, 64 % were male, median age was 19 months (IQR, 12-45 months). HIV status was available for 97 children, of whom 34 % were HIV infected. Lung pathology was observed in 92 % of cases. Bacterial bronchopneumonia was the most common pathology (50 %) undiagnosed ante-mortem in 69 % of cases. Other pathologies included interstitial pneumonitis (17 %), tuberculosis (TB; 8 %), cytomegalovirus pneumonia (7 %) and pneumocystis Jirovecii pneumonia (5 %). Comorbidity between lung pathology and other communicable and non-communicable diseases was observed in 80 % of cases. Lung tissue from 70 % of TB cases was positive for Mycobacterium tuberculosis by molecular diagnostic tests. A total of 80 % of TB cases were comorbid with malnutrition and only 10 % of TB cases were on anti-TB therapy when they died. Conclusions: More proactive testing for bacterial pneumonia and TB in paediatric inpatient settings is needed

Recent advances in the development and evaluation of molecular diagnostics for Ebola virus disease

The 2014-16 outbreak of ebola virus disease (EVD) in West Africa resulted in 11,308 deaths. During the outbreak only 60% of patients were laboratory confirmed and global health authorities have identified the need for accurate and readily deployable molecular diagnostics as an important component of the ideal response to future outbreaks, to quickly identify and isolate patients. Areas covered: Currently PCR-based techniques and rapid diagnostic tests (RDTs) that detect antigens specific to EVD infections dominate the diagnostic landscape, but recent advances in biosensor technologies have led to novel approaches for the development of EVD diagnostics. This review summarises the literature and available performance data of currently available molecular diagnostics for ebolavirus, identifies knowledge gaps and maps out future priorities for research in this field. Expert opinion: While there are now a plethora of diagnostic tests for EVD at various stages of development, there is an acute need for studies to compare their clinical performance, but the sporadic nature of EVD outbreaks makes this extremely challenging, demanding pragmatic new modalities of research funding and ethical/institutional approval, to enable responsive research in outbreak settings. Retrospective head-to-head diagnostic comparisons could also be implemented using biobanked specimens, providing this can be done safely

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

Children infected by human herpesvirus 6B with febrile seizures are more likely to develop febrile status epilepticus: A case-control study in a referral hospital in Zambia

BACKGROUND Human herpesvirus 6B (HHV-6B) is the causative agent of Roseola infantum, and has also been suggested to play a role in the pathogenesis of febrile seizures in young children, a percentage of whom go on to develop febrile status epilepticus (FSE), but the existing data is conflicting and inconclusive. HHV-6A is a distinct species, rarely detected in most parts of the world, but prior studies suggest a higher prevalence in febrile African children. We describe a case-control study comparing the frequency of HHV-6A and/or HHV-6B infections in children with febrile seizures (including FSE) and a control group of febrile children without seizures. METHODS We recruited children aged 6 to 60 months admitted with a febrile illness with (cases) or without (controls) seizures presenting within 48 hours of commencement of fever. Three milliliters of whole blood was centrifuged and plasma stored at -80°C for pooled screening for HHV-6B and HHV-6A by Taqman real-time polymerase chain reaction. RESULTS 102 cases and 95 controls were recruited. The prevalence of HHV-6B DNA detection did not differ significantly between cases (5.8% (6/102)) and controls (10.5% (10/95)) but HHV-6B infection was associated with FSE (OR, 15; 95% CI, [1.99-120]; P= 0.009). HHV-6A was not detected. CONCLUSION Prevalence of HHV-6B was similar among cases and controls. Within the FS group, HHV-6B infection was associated with FSE, suggesting HHV-6B infections could play a role in the pathogenesis of FSE

Burden of tuberculosis at post mortem in inpatients at a tertiary referral centre in sub-Saharan Africa: a prospective descriptive autopsy study

Background Patients with subclinical tuberculosis, smear-negative tuberculosis, extrapulmonary tuberculosis, multidrug-resistant tuberculosis, and asymptomatic tuberculosis are difficult to diagnose and may be missed at all points of health care. We did an autopsy study to ascertain the burden of tuberculosis at post mortem in medical inpatients at a tertiary care hospital in Lusaka, Zambia. Methods Between April 5, 2012, and May 22, 2013, we did whole-body autopsies on inpatients aged at least 16 years who died in the adult inpatient wards at University Teaching Hospital, Lusaka, Zambia. We did gross pathological and histopathological analysis and processed lung tissues from patients with tuberculosis through the GeneXpert MTB/RIF assay to identify patients with multidrug-resistant tuberculosis. The primary outcome measure was specific disease or diseases stratified by HIV status. Secondary outcomes were missed tuberculosis, multidrug-resistant tuberculosis, and comorbidities with tuberculosis. Data were analysed using Pearson chi(2), the Mann-Whitney U test, and binary logistic regression. Findings The median age of the 125 included patients was 35 years (IQR 29-43), 80 (64%) were men, and 101 (81%) were HIV positive. 78 (62%) patients had tuberculosis, of whom 66 (85%) were infected with HIV.35 (45%) of these 78 patients had extrapulmonary tuberculosis. The risk of extrapulmonary tuberculosis was higher among HIV-infected patients than among uninfected patients (adjusted odds ratio 5.14, 95% CI 1.04-24.5; p=0.045). 20 (26%) of 78 patients with tuberculosis were not diagnosed during their life and 13 (17%) had undiagnosed multidrug-resistant tuberculosis. Common comorbidities with tuberculosis were pyogenic pneumonia in 26 patients (33%) and anaemia in 15 (19%). Interpretation Increased clinical awareness and more proactive screening for tuberculosis and multidrug-resistant tuberculosis in inpatient settings is needed. Further autopsy studies are needed to ascertain the generalisability of the findings

Tuberculosis at post-mortem in inpatient adults at a tertiary referral centre in sub-Saharan Africa – A prospective descriptive autopsy study

Background: The World Health Organisation (WHO) estimates that 3 million cases of tuberculosis (TB) are missed every year. Identification and treatment of these are critical to achieving global TB control. Patients with sub-clinical TB, extra-pulmonary TB, and drug-resistant TB are difficult to diagnose and may be missed at all points of healthcare. An autopsy study was conducted to ascertain the burden of TB at post-mortem in adults who died in the inpatient general medical wards at a tertiary care referral center in Lusaka, Zambia. Methods: Complete whole body autopsies were performed on 125 adult inpatients. Pathological examination involved two stages: (1) Gross pathology was recorded, and samples were taken from all organs for histopathology and cryopreservation; and (2) Histopathological examination of tissue after appropriate staining. Specific pathology and diseases identified on examination were recorded. Lung tissues were processed using the GeneXpert MTB/RIF Assay. Primary outcome measures were specific diseases stratified by HIV status. Secondary outcomes were missed TB and drug-resistant TB cases. Findings: Of 125 adults, median age 35 years (IQR: 29-43), 80 (64%) were male and 101 (80.8%) were HIV-positive. Tuberculosis was the most common finding at autopsy with 78/125 cases (62.4%), of which 66/78 (84.6%) were HIV-infected. There were 35/78 cases (44.9%) with extra-pulmonary TB, the odds of which were higher among HIV-infected cases (aOR 5.14 (95% CI: 1.04–25.4), p = 0.045); 25.6% (20/78) of the TB cases were not diagnosed ante-mortem; and 13/78 (16.7%) of the TB cases had undiagnosed MDR-TB. Other autopsy findings included: pyogenic pneumonia 36.8% (46/125); bacterial meningitis 7.2% (9/125); cardiac failure 7.2% (9/125); and malignancies 8.8% (11/125). Prevalence of HIV did not differ between TB and non-TB cases (84.6% vs. 74.5%: p = 0.163). Interpretation: TB remains an important cause of death in adult inpatients. A substantial number of inpatients with TB and MDR-TB are not diagnosed by the current cascade of healthcare. Inpatient settings in high TB endemic countries should be included in WHO ‘high risk’ groups, and heightened clinical awareness and more proactive screening for TB and MDR-TB in all inpatients should be required

Evaluation of SARS-CoV-2 diagnostics and risk factors associated with SARS-CoV-2 infection in Zambia.

OBJECTIVES To conduct a diagnostic validation study of SARS-CoV-2 diagnostic kits. METHODS We compared SARS-CoV-2 diagnostic test results from 3 RT-PCR assays used by the Zambian government between November 2020 and February 2021 (Panther Fusion assay, Da An Gene's 2019-nCoV RNA kit and Maccura's PCR Kit) with the Altona RealStar RT-PCR kit which served as the gold standard. We also evaluated results from rapid antigen testing and whether comorbidities were linked with increased odds of infection. RESULTS We recruited 244 participants, 61% (149/244) were positive by at least 1 PCR assay. Da An Gene, Maccura, and Panther Fusion assays had sensitivities of 0.0% (95% confidence interval [CI] 0%-41%), 27.1% (95% CI 15%-42%), and 76% (95% CI 65%-85%), respectively, but specificity was low (<85% for all 3 assays). HIV and TB were not associated with SARS-CoV-2, whereas female sex (OR 0.5 [0.3-0.9], p = 0.026) and chronic pulmonary disease (0.1 [0.0-0.8], p = 0.031) were associated with lower odds of SARS-CoV-2 infection. Of 44 samples, 84% sequenced were Beta variant. CONCLUSIONS The RT-PCR assays evaluated did not meet WHO recommended minimum sensitivity of 80%. Local diagnostic validation studies should be embedded within preparedness plans for future outbreaks to improve the public health response

Preventing Bloodstream Infections and Death in Zambian Neonates: Impact of a Low-cost Infection Control Bundle

Background Sepsis is a leading cause of neonatal mortality in low-resource settings. As facility-based births become more common, the proportion of neonatal deaths due to hospital-onset sepsis has increased. Methods We conducted a prospective cohort study in a neonatal intensive care unit in Zambia where we implemented a multi-faceted infection prevention and control (IPC) bundle consisting of IPC training, text message reminders, alcohol hand rub, enhanced environmental cleaning, and weekly bathing of babies ≥1.5 kg with 2% chlorhexidine gluconate. Hospital-associated sepsis, bloodstream infection (BSI), and mortality (>3 days after admission) outcome data were collected for 6 months prior to and 11 months after bundle implementation. Results Most enrolled neonates had a birthweight ≥1.5 kg (2131/2669, 79.8%). Hospital-associated mortality was lower during the intervention than baseline period (18.0% vs 23.6%). Total mortality was lower in the intervention than prior periods. Half of enrolled neonates (50.4%) had suspected sepsis; 40.8% of cultures were positive. Most positive blood cultures yielded a pathogen (409/549, 74.5%), predominantly Klebsiella pneumoniae (289/409, 70.1%). The monthly rate and incidence density rate of suspected sepsis were lower in the intervention period for all birthweight categories, except babies weighing <1.0 kg. The rate of BSI with pathogen was also lower in the intervention than baseline period. Conclusions A simple IPC bundle can reduce sepsis and death in neonates hospitalized in high-risk, low-resource settings. Further research is needed to validate these findings in similar settings and to identify optimal implementation strategies for improvement and sustainability. Clinical Trials Registration. NCT02386592

Etiology, antibiotic resistance and risk factors for neonatal sepsis in a large referral center in Zambia

Background: In sub-Saharan Africa, there is scanty data on the causes of neonatal sepsis and antimicrobial resistance among common invasive pathogens that might guide policy and practice. Methods: A cross-sectional observational prevalence and etiology study of neonates with suspected sepsis admitted to the neonatal intensive care unit, University Teaching Hospital, Lusaka, Zambia, between October 2013 and May 2014. Data from blood cultures and phenotypic antibiotic susceptibility testing were compared with multivariate analysis of risk factors for neonatal sepsis. Results: Of 313 neonates with suspected sepsis, 54% (170/313) were male; 20% (62/313) were born to HIV-positive mothers; 33% (103/313) had positive blood cultures, of which 85% (88/103) were early-onset sepsis. Klebsiella species was the most prevalent isolate, accounting for 75% (77/103) of cases, followed by coagulase-negative staphylococci 6% (7/103)], Staphylococcus aureus 6% (6/103)], Escherichia coli 5% (5/103)] and Candida species 5% (5/103)]. For Klebsiella species, antibiotic resistance ranged from 96%-99% for World Health Organizationrecommended first-line therapy (gentamicin and ampicillin/penicillin) to 94%-97% for third-generation cephalosporins. The prevalence of cultureconfirmed sepsis increased from 0 to 39% during the period December 2013 to March 2014, during which time mortality increased 29%-47%; 93% (14/15) of late-onset sepsis and 82% (37/45) of early-onset sepsis aged 4-7 days were admitted > 2 days before the onset of symptoms. Culture results for only 25% (26/103) of cases were available before discharge or death. Maternal HIV infection was associated with a reduced risk of neonatal sepsis odds ratio, 0.46 (0.23-0.93); P = 0.029]. Conclusions: Outbreaks of nosocomial multiantibiotic-resistant infections are an important cause of neonatal sepsis and associated mortality. Reduced risk of neonatal sepsis associated with maternal HIV infection is counterintuitive and requires further investigation