Clinical and molecular epidemiolgy of human rhinoviruses in low to middle income countries

A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy Johannesburg 2017.Introduction: Human rhinovirus (HRV) is the most prevalent virus detected in children with respiratory symptoms; however, its aetiological role during disease episodes remains unclear as detection of HRV is also ubiquitous among asymptomatic children. We evaluated the clinical epidemiology of HRV-associated disease among children hospitalised with severe and very severe pneumonia together with community control children living in Africa and Southeast Asia. In addition, we explored the associations between the molecular subtyping and nasopharyngeal viral loads of the HRV species and their ability to cause viraemia as potential markers for HRV disease. Methods: Using a case-control study conducted in seven countries, we compared the clinical characteristics of children (1-59 months of age) hospitalised with HRV-associated pneumonia between August 2011 - January 2014 and age-frequency matched controls. Nasopharyngeal swabs from the cases and controls were tested for HRV, together with 27 other respiratory pathogens, with quantitative real-time PCR assays. The 5’ NCR region of the HRV positive samples were sequenced to determine the species/strains of HRV and phylogenetic analysis was performed. Additionally, the blood samples from a limited number of cases (n=210) and controls (n=212) were tested for the presence of HRV viraemia and the 5’ NCR sequence of positive blood samples were further characterised. Results: Overall, HRV detection was 1.45-fold (aOR 95% CI: 1.29-1.62) higher among children hospitalised with pneumonia (24%) compared to controls (21%, P<0.005); including being 2.08-fold (28% vs 18%, aOR 95% CI: 1.75-2.47) more associated with case status among children 12-59 months of age. The HRV-associated cases were younger (13.1 months) than controls with HRV infection (15.4 months, P=0.001) and more likely to be malnourished (30% vs. 12%, P<0.001) and HIV-1 exposed (10% vs. 8%, P=0.046). HRV nasopharyngeal viral load was significantly higher among cases compared to controls (3.7 vs. 3.5 log10 copies/mL, P<0.001). Also, HRV viraemia was 7.02-fold (aOR 95% CI 1.70-28.94) more prevalent among cases (7%) compared to controls (2%, P=0.007). Moreover, HRV nasopharyngeal viral loads ≥4 log10 copies/mL differentiated between viraemia positive and negative cases. There was, however, no difference in the molecular subtyping of the HRV species prevalence among cases (HRV-A:48%; HRV-B:7%; HRV-C:45%) and controls (HRV-A:45%; HRV-B:10%; HRV-C:45%, P=0.496); as well as no evidence of seasonal or temporal clustering of the HRV species over time. Among cases, HRV detection was less likely to be associated with presence of radiographically confirmed pneumonia (40% vs 46%, P=0.001) or hospital stay >3 days (52% vs 61%, P=0.001). It was, however, positively associated with older age (13.1 months vs. 11.3 months, P<0.001) and presence of wheeze (46% vs. 31%, P<0.001) compared to the HRV uninfected cases. HRV was the sole virus detected in the 53% of cases and generally there were no differences in severity or clinical presentation among cases with HRV mono-infections compared to those with HRV-mixed infections. The HRV mono-infections, however, were associated with a 2.83-fold (aOR 95% CI: 1.44-5.53) higher case fatality ratio than cases with HRV and other viral mixed infections (10% vs. 5%, P=0.002). The HRV-associated case fatalities were more likely to have markers of bacterial co-infections compared to the HRV-associated cases that survived. Among the HRV species, HRV-C compared to HRV-A cases were older (12.1 vs. 9.4 months, P=0.033), more likely to present with wheeze (35% vs. 25%, P=0.031) and 2.59-fold (aOR 95% CI: 1.23-5.95) more likely to be associated with viraemia (12% vs. 2%, P=0.025). Conversely, the HRV-A infected cases were more likely to have radiographically confirmed pneumonia (46%) compared to HRV-C infected cases (36%, P=0.040) and HRV-A mono-infected cases were more likely to have hospital stay of >3 days (72%) than HRV-C mono-infected cases (54%, P=0.039). Conclusion: HRV detection, especially among children 1-5 years of age, was associated with severe lower respiratory tract infection; however, HRV detection was ubiquitous with a high degree of genetic diversity among both cases and controls. Thus the true etiologic role of HRV during childhood disease, especially among infants, remains uncertain. Nonetheless, HRV nasopharyngeal viral loads ≥4log10 copies/mL in conjunction with HRV viraemia are potential markers for HRV-associated severe respiratory disease. Among cases, HRV-A was associated with radiographically confirmed pneumonia and generally more severe disease than HRV-C which was more associated with viraemia and wheezing disease.MT201

Child deaths caused by klebsiella pneumoniae in sub-saharan Africa and south Asia: A secondary analysis of child health and mortality prevention surveillance (CHAMPS) data.

Background; Klebsiella pneumoniae is an important cause of nosocomial and community-acquired pneumonia and sepsis in children, and antibiotic-resistant K pneumoniae is a growing public health threat. We aimed to characterize child mortality associated with this pathogen in seven high-mortality settings. Methods; We analysed Child Health and Mortality Prevention Surveillance (CHAMPS) data on the causes of deaths in children younger than 5 years and stillbirths in sites located in seven countries across sub-Saharan Africa (Ethiopia, Kenya, Mali, Mozambique, Sierra Leone, and South Africa) and south Asia (Bangladesh) from Dec 9, 2016, to Dec 31, 2021. CHAMPS sites conduct active surveillance for deaths in catchment populations and following reporting of an eligible death or stillbirth seek consent for minimally invasive tissue sampling followed by extensive aetiological testing (microbiological, molecular, and pathological); cases are reviewed by expert panels to assign immediate, intermediate, and underlying causes of death. We reported on susceptibility to antibiotics for which at least 30 isolates had been tested, and excluded data on antibiotics for which susceptibility testing is not recommended for Klebsiella spp due to lack of clinical activity (eg, penicillin and ampicillin). Findings; Among 2352 child deaths with cause of death assigned, 497 (21%, 95% CI 20–23) had K pneumoniae in the causal chain of death; 100 (20%, 17–24) had K pneumoniae as the underlying cause. The frequency of K pneumoniae in the causal chain was highest in children aged 1–11 months (30%, 95% CI 26–34; 144 of 485 deaths) and 12–23 months (28%, 22–34; 63 of 225 deaths); frequency by site ranged from 6% (95% CI 3–11; 11 of 184 deaths) in Bangladesh to 52% (44–61; 71 of 136 deaths) in Ethiopia. K pneumoniae was in the causal chain for 450 (22%, 95% CI 20–24) of 2023 deaths that occurred in health facilities and 47 (14%, 11–19) of 329 deaths in the community. The most common clinical syndromes among deaths with K pneumoniae in the causal chain were sepsis (44%, 95% CI 40–49; 221 of 2352 deaths), sepsis in conjunction with pneumonia (19%, 16–23; 94 of 2352 deaths), and pneumonia (16%, 13–20; 80 of 2352 deaths). Among K pneumoniae isolates tested, 121 (84%) of 144 were resistant to ceftriaxone and 80 (75%) of 106 to gentamicin. Interpretation; K pneumoniae substantially contributed to deaths in the first 2 years of life across multiple high-mortality settings, and resistance to antibiotics used for sepsis treatment was common. Improved strategies are needed to rapidly identify and appropriately treat children who might be infected with this pathogen. These data suggest a potential impact of developing and using effective K pneumoniae vaccines in reducing neonatal, infant, and child deaths globally

Estimated SARS-CoV-2 infection rate and fatality risk in Gauteng Province, South Africa : a population-based seroepidemiological survey

DATA AVAILABILITY : De-identified individual-level data and data sets generated during the current study are available for researchers who provide a methodologically sound proposal. If approved, the requestor must sign a data-use agreement. Additionally, the study protocol is available on request. All requests must be addressed to the corresponding author. Data will be available 3 months after publication of this manuscript.BACKGROUND : Limitations in laboratory testing capacity undermine the ability to quantify the overall burden of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. METHODS : We undertook a population-based serosurvey for SARS-CoV-2 infection in 26 subdistricts, Gauteng Province (population 15.9 million), South Africa, to estimate SARS-CoV-2 infection, infection fatality rate (IFR) triangulating seroprevalence, recorded COVID-19 deaths and excess-mortality data. We employed three-stage random household sampling with a selection probability proportional to the subdistrict size, stratifying the subdistrict census-sampling frame by housing type and then selecting households from selected clusters. The survey started on 4 November 2020, 8 weeks after the end of the first wave (SARS-CoV-2 nucleic acid amplification test positivity had declined to <10% for the first wave) and coincided with the peak of the second wave. The last sampling was performed on 22 January 2021, which was 9 weeks after the SARS-CoV-2 resurgence. Serum SARS-CoV-2 receptor-binding domain (RBD) immunoglobulin-G (IgG) was measured using a quantitative assay on the Luminex platform. RESULTS : From 6332 individuals in 3453 households, the overall RBD IgG seroprevalence was 19.1% [95% confidence interval (CI): 18.1–20.1%] and similar in children and adults. The seroprevalence varied from 5.5% to 43.2% across subdistricts. Conservatively, there were 2 897 120 (95% CI: 2 743 907–3 056 866) SARS-CoV-2 infections, yielding an infection rate of 19 090 per 100 000 until 9 January 2021, when 330 336 COVID-19 cases were recorded. The estimated IFR using recorded COVID-19 deaths (n = 8198) was 0.28% (95% CI: 0.27–0.30) and 0.67% (95% CI: 0.64–0.71) assuming 90% of modelled natural excess deaths were due to COVID-19 (n = 21 582). Notably, 53.8% (65/122) of individuals with previous self-reported confirmed SARS-CoV-2 infection were RBD IgG seronegative. CONCLUSIONS : The calculated number of SARS-CoV-2 infections was 7.8-fold greater than the recorded COVID-19 cases. The calculated SARS-CoV-2 IFR varied 2.39-fold when calculated using reported COVID-19 deaths (0.28%) compared with excess-mortality-derived COVID-19-attributable deaths (0.67%). Waning RBD IgG may have inadvertently underestimated the number of SARS-CoV-2 infections and conversely overestimated the mortality risk. Epidemic preparedness and response planning for future COVID-19 waves will need to consider the true magnitude of infections, paying close attention to excess-mortality trends rather than absolute reported COVID-19 deaths.The Bill and Melinda Gates Foundation.https://academic.oup.com/ijehj2023Family Medicin

The Incremental Value of Repeated Induced Sputum and Gastric Aspirate Samples for the Diagnosis of Pulmonary Tuberculosis in Young Children With Acute Community-Acquired Pneumonia

Background. Mycobacterium tuberculosis (Mtb) contributes to the pathogenesis of childhood acute community-acquired pneumonia in settings with a high tuberculosis burden. The incremental value of a repeated induced sputum (IS) sample, compared with a single IS or gastric aspirate (GA) sample, is not well known. Methods. Two IS samples were obtained for Mtb culture from children enrolled as cases in the Pneumonia Etiology Research for Child Health (PERCH) study in South Africa. Nonstudy attending physicians requested GA if pulmonary tuberculosis was clinically suspected. We compared the Mtb yield of 2 IS samples to that of 1 IS sample and GA samples. Results . Twenty-seven (3.0%) culture-confirmed pulmonary tuberculosis cases were identified among 906 children investigated with IS and GA samples for Mtb. Results from 2 IS samples were available for 719 children (79.4%). Of 12 culture-confirmed pulmonary tuberculosis cases identified among children with ≥2 IS samples, 4 (33.3%) were negative at the first IS sample. In head-to-head comparisons among children with both GA and IS samples collected, the yield of 1 GA sample (8 of 427; 1.9%) was similar to that of 1 IS sample (5 of 427, 1.2%), and the yield of 2 GA samples (10 of 300; 3.3%) was similar to that of 2 IS samples (5 of 300; 1.7%). IS samples identified 8 (42.1%) of the 19 culture-confirmed pulmonary tuberculosis cases that were identified through submission of IS and GA samples. Conclusions. A single IS sample underestimated the presence of Mtb in children hospitalized with severe or very severe pneumonia. Detection of Mtb is enhanced by combining 2 IS with GA sample collections in young children with acute severe pneumonia

Efficacy of primary series AZD1222 (ChAdOx1 nCoV-19) vaccination against SARS-CoV-2 variants of concern: Final analysis of a randomized, placebo-controlled, phase 1b/2 study in South African adults (COV005)

COVID-19 vaccine efficacy (VE) has been observed to vary against antigenically distinct SARS-CoV-2 variants of concern (VoC). Here we report the final analysis of VE and safety from COV005: a phase 1b/2, multicenter, double-blind, randomized, placebo-controlled study of primary series AZD1222 (ChAdOx1 nCoV-19) vaccination in South African adults aged 18-65 years. South Africa's first, second, and third waves of SARS-CoV-2 infections were respectively driven by the ancestral SARS-CoV-2 virus (wild type, WT), and SARS-CoV-2 Beta and Delta VoCs. VE against asymptomatic and symptomatic infection was 90.6% for WT, 6.7% for Beta and 77.1% for Delta. No cases of severe COVID-19 were documented ahead of unblinding. Safety was consistent with the interim analysis, with no new safety concerns identified. Notably, South Africa's Delta wave occurred ≥ 9 months after primary series vaccination, suggesting that primary series AZD1222 vaccination offers a good durability of protection, potentially due to an anamnestic response. Clinical trial identifier: CT.gov NCT04444674

Child deaths caused by Klebsiella pneumoniae in sub-Saharan Africa and south Asia: a secondary analysis of Child Health and Mortality Prevention Surveillance (CHAMPS) data

Background: Klebsiella pneumoniae is an important cause of nosocomial and community-acquired pneumonia and sepsis in children, and antibiotic-resistant K pneumoniae is a growing public health threat. We aimed to characterise child mortality associated with this pathogen in seven high-mortality settings. Methods: We analysed Child Health and Mortality Prevention Surveillance (CHAMPS) data on the causes of deaths in children younger than 5 years and stillbirths in sites located in seven countries across sub-Saharan Africa (Ethiopia, Kenya, Mali, Mozambique, Sierra Leone, and South Africa) and south Asia (Bangladesh) from Dec 9, 2016, to Dec 31, 2021. CHAMPS sites conduct active surveillance for deaths in catchment populations and following reporting of an eligible death or stillbirth seek consent for minimally invasive tissue sampling followed by extensive aetiological testing (microbiological, molecular, and pathological); cases are reviewed by expert panels to assign immediate, intermediate, and underlying causes of death. We reported on susceptibility to antibiotics for which at least 30 isolates had been tested, and excluded data on antibiotics for which susceptibility testing is not recommended for Klebsiella spp due to lack of clinical activity (eg, penicillin and ampicillin). Findings: Among 2352 child deaths with cause of death assigned, 497 (21%, 95% CI 20–23) had K pneumoniae in the causal chain of death; 100 (20%, 17–24) had K pneumoniae as the underlying cause. The frequency of K pneumoniae in the causal chain was highest in children aged 1–11 months (30%, 95% CI 26–34; 144 of 485 deaths) and 12–23 months (28%, 22–34; 63 of 225 deaths); frequency by site ranged from 6% (95% CI 3–11; 11 of 184 deaths) in Bangladesh to 52% (44–61; 71 of 136 deaths) in Ethiopia. K pneumoniae was in the causal chain for 450 (22%, 95% CI 20–24) of 2023 deaths that occurred in health facilities and 47 (14%, 11–19) of 329 deaths in the community. The most common clinical syndromes among deaths with K pneumoniae in the causal chain were sepsis (44%, 95% CI 40–49; 221 of 2352 deaths), sepsis in conjunction with pneumonia (19%, 16–23; 94 of 2352 deaths), and pneumonia (16%, 13–20; 80 of 2352 deaths). Among K pneumoniae isolates tested, 121 (84%) of 144 were resistant to ceftriaxone and 80 (75%) of 106 to gentamicin. Interpretation: K pneumoniae substantially contributed to deaths in the first 2 years of life across multiple high-mortality settings, and resistance to antibiotics used for sepsis treatment was common. Improved strategies are needed to rapidly identify and appropriately treat children who might be infected with this pathogen. These data suggest a potential impact of developing and using effective K pneumoniae vaccines in reducing neonatal, infant, and child deaths globally

Initial findings from a novel population-based child mortality surveillance approach: a descriptive study.

--- - Label: BACKGROUND NlmCategory: BACKGROUND content: "Sub-Saharan Africa and south Asia contributed 81% of 5\xC2\xB79 million under-5 deaths and 77% of 2\xC2\xB76 million stillbirths worldwide in 2015. Vital registration and verbal autopsy data are mainstays for the estimation of leading causes of death, but both are non-specific and focus on a single underlying cause. We aimed to provide granular data on the contributory causes of death in stillborn fetuses and in deceased neonates and children younger than 5 years, to inform child mortality prevention efforts." - Label: METHODS NlmCategory: METHODS content: "The Child Health and Mortality Prevention Surveillance (CHAMPS) Network was established at sites in seven countries (Baliakandi, Bangladesh; Harar and Kersa, Ethiopia; Siaya and Kisumu, Kenya; Bamako, Mali; Manhi\xC3\xA7a, Mozambique; Bombali, Sierra Leone; and Soweto, South Africa) to collect standardised, population-based, longitudinal data on under-5 mortality and stillbirths in sub-Saharan Africa and south Asia, to improve the accuracy of determining causes of death. Here, we analysed data obtained in the first 2 years after the implementation of CHAMPS at the first five operational sites, during which surveillance and post-mortem diagnostics, including minimally invasive tissue sampling (MITS), were used. Data were abstracted from all available clinical records of deceased children, and relevant maternal health records were also extracted for stillbirths and neonatal deaths, to incorporate reported pregnancy or delivery complications. Expert panels followed standardised procedures to characterise causal chains leading to death, including underlying, intermediate (comorbid or antecedent causes), and immediate causes of death for stillbirths, neonatal deaths, and child (age 1-59 months) deaths." - Label: FINDINGS NlmCategory: RESULTS content: Between Dec 10, 2016, and Dec 31, 2018, MITS procedures were implemented at five sites in Mozambique, South Africa, Kenya, Mali, and Bangladesh. We screened 2385 death notifications for inclusion eligibility, following which 1295 families were approached for consent; consent was provided for MITS by 963 (74%) of 1295 eligible cases approached. At least one cause of death was identified in 912 (98%) of 933 cases (180 stillbirths, 449 neonatal deaths, and 304 child deaths); two or more conditions were identified in the causal chain for 585 (63%) of 933 cases. The most common underlying causes of stillbirth were perinatal asphyxia or hypoxia (130 [72%] of 180 stillbirths) and congenital infection or sepsis (27 [15%]). The most common underlying causes of neonatal death were preterm birth complications (187 [42%] of 449 neonatal deaths), perinatal asphyxia or hypoxia (98 [22%]), and neonatal sepsis (50 [11%]). The most common underlying causes of child deaths were congenital birth defects (39 [13%] of 304 deaths), lower respiratory infection (37 [12%]), and HIV (35 [12%]). In 503 (54%) of 933 cases, at least one contributory pathogen was identified. Cytomegalovirus, Escherichia coli, group B Streptococcus, and other infections contributed to 30 (17%) of 180 stillbirths. Among neonatal deaths with underlying prematurity, 60% were precipitated by other infectious causes. Of the 275 child deaths with infectious causes, the most common contributory pathogens were Klebsiella pneumoniae (86 [31%]), Streptococcus pneumoniae (54 [20%]), HIV (40 [15%]), and cytomegalovirus (34 [12%]), and multiple infections were common. Lower respiratory tract infection contributed to 174 (57%) of 304 child deaths. - Label: INTERPRETATION NlmCategory: CONCLUSIONS content: Cause of death determination using MITS enabled detailed characterisation of contributing conditions. Global estimates of child mortality aetiologies, which are currently based on a single syndromic cause for each death, will be strengthened by findings from CHAMPS. This approach adds specificity and provides a more complete overview of the chain of events leading to death, highlighting multiple potential interventions to prevent under-5 mortality and stillbirths. - Label: FUNDING NlmCategory: BACKGROUND content: Bill & Melinda Gates Foundation

Evaluation of Pneumococcal Load in Blood by Polymerase Chain Reaction for the Diagnosis of Pneumococcal Pneumonia in Young Children in the PERCH Study.

BACKGROUND.: Detection of pneumococcus by lytA polymerase chain reaction (PCR) in blood had poor diagnostic accuracy for diagnosing pneumococcal pneumonia in children in 9 African and Asian sites. We assessed the value of blood lytA quantification in diagnosing pneumococcal pneumonia. METHODS.: The Pneumonia Etiology Research for Child Health (PERCH) case-control study tested whole blood by PCR for pneumococcus in children aged 1-59 months hospitalized with signs of pneumonia and in age-frequency matched community controls. The distribution of load among PCR-positive participants was compared between microbiologically confirmed pneumococcal pneumonia (MCPP) cases, cases confirmed for nonpneumococcal pathogens, nonconfirmed cases, and controls. Receiver operating characteristic analyses determined the "optimal threshold" that distinguished MCPP cases from controls. RESULTS.: Load was available for 290 of 291 cases with pneumococcal PCR detected in blood and 273 of 273 controls. Load was higher in MCPP cases than controls (median, 4.0 × 103 vs 0.19 × 103 copies/mL), but overlapped substantially (range, 0.16-989.9 × 103 copies/mL and 0.01-551.9 × 103 copies/mL, respectively). The proportion with high load (≥2.2 log10 copies/mL) was 62.5% among MCPP cases, 4.3% among nonconfirmed cases, 9.3% among cases confirmed for a nonpneumococcal pathogen, and 3.1% among controls. Pneumococcal load in blood was not associated with respiratory tract illness in controls (P = .32). High blood pneumococcal load was associated with alveolar consolidation on chest radiograph in nonconfirmed cases, and with high (>6.9 log10 copies/mL) nasopharyngeal/oropharyngeal load and C-reactive protein ≥40 mg/L (both P < .01) in nonconfirmed cases but not controls. CONCLUSIONS.: Quantitative pneumococcal PCR in blood has limited diagnostic utility for identifying pneumococcal pneumonia in individual children, but may be informative in epidemiological studies

Is Higher Viral Load in the Upper Respiratory Tract Associated With Severe Pneumonia? Findings From the PERCH Study.

BACKGROUND.: The etiologic inference of identifying a pathogen in the upper respiratory tract (URT) of children with pneumonia is unclear. To determine if viral load could provide evidence of causality of pneumonia, we compared viral load in the URT of children with World Health Organization-defined severe and very severe pneumonia and age-matched community controls. METHODS.: In the 9 developing country sites, nasopharyngeal/oropharyngeal swabs from children with and without pneumonia were tested using quantitative real-time polymerase chain reaction for 17 viruses. The association of viral load with case status was evaluated using logistic regression. Receiver operating characteristic (ROC) curves were constructed to determine optimal discriminatory viral load cutoffs. Viral load density distributions were plotted. RESULTS.: The mean viral load was higher in cases than controls for 7 viruses. However, there was substantial overlap in viral load distribution of cases and controls for all viruses. ROC curves to determine the optimal viral load cutoff produced an area under the curve of <0.80 for all viruses, suggesting poor to fair discrimination between cases and controls. Fatal and very severe pneumonia cases did not have higher viral load than less severe cases for most viruses. CONCLUSIONS.: Although we found higher viral loads among pneumonia cases than controls for some viruses, the utility in using viral load of URT specimens to define viral pneumonia was equivocal. Our analysis was limited by lack of a gold standard for viral pneumonia

Causes of death among infants and children in the Child Health and Mortality Prevention Surveillance (CHAMPS) network

Importance The number of deaths of children younger than 5 years has been steadily decreasing worldwide, from more than 17 million annual deaths in the 1970s to an estimated 5.3 million in 2019 (with 2.8 million deaths occurring in those aged 1-59 months [53% of all deaths in children aged <5 years]). More detailed characterization of childhood deaths could inform interventions to improve child survival. Objective To describe causes of postneonatal child deaths across 7 mortality surveillance sentinel sites in Africa and Asia. Design, Setting, and Participants The Child Health and Mortality Prevention Surveillance (CHAMPS) Network conducts childhood mortality surveillance in sub-Saharan Africa and South Asia using innovative postmortem minimally invasive tissue sampling (MITS). In this cross-sectional study, MITS was conducted in deceased children aged 1 to 59 months at 7 sites in sub-Saharan Africa and South Asia from December 3, 2016, to December 3, 2020. Data analysis was conducted between October and November 2021. Main Outcomes and Measures The expert panel attributed underlying, intermediate, and immediate conditions in the chain of events leading to death, based on histopathologic analysis, microbiological diagnostics, clinical data, and verbal autopsies. Results In this study, MITS was performed in 632 deceased children (mean [SD] age at death, 1.3 [0.3] years; 342 [54.1%] male). The 6 most common underlying causes of death were malnutrition (104 [16.5%]), HIV (75 [11.9%]), malaria (71 [11.2%]), congenital birth defects (64 [10.1%]), lower respiratory tract infections (LRTIs; 53 [8.4%]), and diarrheal diseases (46 [7.2%]). When considering immediate causes only, sepsis (191 [36.7%]) and LRTI (129 [24.8%]) were the 2 dominant causes. An infection was present in the causal chain in 549 of 632 deaths (86.9%); pathogens most frequently contributing to infectious deaths included Klebsiella pneumoniae (155 of 549 infectious deaths [28.2%]; 127 [81.9%] considered nosocomial), Plasmodium falciparum (122 of 549 [22.2%]), and Streptococcus pneumoniae (109 of 549 [19.9%]). Other organisms, such as cytomegalovirus (57 [10.4%]) and Acinetobacter baumannii (39 [7.1%]; 35 of 39 [89.7%] considered nosocomial), also played important roles. For the top underlying causes of death, the median number of conditions in the chain of events leading to death was 3 for malnutrition, 3 for HIV, 1 for malaria, 3 for congenital birth defects, and 1 for LRTI. Expert panels considered 494 of 632 deaths (78.2%) preventable and 26 of 632 deaths (4.1%) preventable under certain conditions. Conclusions and Relevance In this cross-sectional study investigating causes of child mortality in the CHAMPS Network, results indicate that, in these high-mortality settings, infectious diseases continue to cause most deaths in infants and children, often in conjunction with malnutrition. These results also highlight opportunities for action to prevent deaths and reveal common interaction of various causes in the path toward death