Collaboration and infrastructure is needed to develop an African perspective on micro(nano)plastic pollution

Abstract: Our current understanding of environmental micro(nano)plastic (MNP) pollution is driven by field and lab-based studies performed predominantly by and in wealthier countries. However, mismanaged waste and its consequences affect low- and middle-income countries over-proportionately. Evidence suggests that studies on MNP pollution in Africa are critically limited by the scientific infrastructure available, restricting research activities to opportunities for external collaboration with established research laboratories in the Global North. The development of Pan-African research networks and analytical nodes, is required to support intra-African research exchange and training, and drive evidence-based policy relevant to an African context. This can facilitate more inclusive conversations around the harmonization and standardization of methods currently mainly available to the Global North

High cases of submicroscopic Plasmodium falciparum infections in a suburban population of Lagos, Nigeria.

BACKGROUND: Asymptomatic malaria parasites are significant sources of infections for onward malaria transmission. Conventional tools for malaria diagnosis such as microscopy and rapid diagnostic test kits (RDT) have relatively low sensitivity, hence the need for alternative tools for active screening of such low-density infections. METHODS: This study tested var acidic terminal sequence-based (varATS) quantitative polymerase chain reaction (qPCR) for screening asymptomatic Plasmodium falciparum infections among dwellers of a sub-urban community in Lagos, Nigeria. Clinically healthy participants were screened for malaria using microscopy, RDT and varATS qPCR techniques. Participants were stratified into three age groups: 1-5, 6-14 and > 14 years old. RESULTS: Of the 316 participants screened for asymptomatic malaria infection, 78 (24.68%) were positive by microscopy, 99 (31.33%) were positive by RDT and 112 (35.44%) by varATS qPCR. Participants aged 6-14 years had the highest prevalence of asymptomatic malaria, with geometric means of ~ 116 parasites/µL and ~ 6689 parasites/µL as detected by microscopy and varATS, respectively. CONCLUSION: This study has revealed high prevalence of asymptomatic malaria in the study population, with varATS detecting additional sub-microscopic infections. The highest concentration of asymptomatic malaria was observed among school-age children between 6 and 14 years old. A large-scale screening to identify other potential hotspots of asymptomatic parasites in the country is recommended

Estimating the prevalence of overweight and obesity in Nigeria in 2020: a systematic review and meta-analysis

Background Targeted public health response to obesity in Nigeria is relatively low due to limited epidemiologic understanding. We aimed to estimate nationwide and sub-national prevalence of overweight and obesity in the adult Nigerian population. Methods MEDLINE, EMBASE, Global Health, and Africa Journals Online were systematically searched for relevant epidemiologic studies in Nigeria published on or after 01 January 1990. We assessed quality of studies and conducted a random-effects meta-analysis on extracted crude prevalence rates. Using a meta-regression model, we estimated the number of overweight and obese persons in Nigeria in the year 2020. Results From 35 studies (n = 52,816), the pooled crude prevalence rates of overweight and obesity in Nigeria were 25.0% (95% confidence interval, CI: 20.4–29.6) and 14.3% (95% CI: 12.0–15.5), respectively. The prevalence in women was higher compared to men at 25.5% (95% CI: 17.1–34.0) versus 25.2% (95% CI: 18.0–32.4) for overweight, and 19.8% (95% CI: 3.9–25.6) versus 12.9% (95% CI: 9.1–16.7) for obesity, respectively. The pooled mean body mass index (BMI) and waist circumference were 25.6 kg/m2 and 86.5 cm, respectively. We estimated that there were 21 million and 12 million overweight and obese persons in the Nigerian population aged 15 years or more in 2020, accounting for an age-adjusted prevalence of 20.3% and 11.6%, respectively. The prevalence rates of overweight and obesity were consistently higher among urban dwellers (27.2% and 14.4%) compared to rural dwellers (16.4% and 12.1%). Conclusions Our findings suggest a high prevalence of overweight and obesity in Nigeria. This is marked in urban Nigeria and among women, which may in part be due to widespread sedentary lifestyles and a surge in processed food outlets, largely reflective of a trend across many African settings

The global EPTO database: Worldwide occurrences of aquatic insects

Motivation: Aquatic insects comprise 64% of freshwater animal diversity and are widely used as bioindicators to assess water quality impairment and freshwater ecosystem health, as well as to test ecological hypotheses. Despite their importance, a comprehensive, global database of aquatic insect occurrences for mapping freshwater biodiversity in macroecological studies and applied freshwater research is missing. We aim to fill this gap and present the Global EPTO Database, which includes worldwide geo-referenced aquatic insect occurrence records for four major taxa groups: Ephemeroptera, Plecoptera, Trichoptera and Odonata (EPTO). Main type of variables contained: A total of 8,368,467 occurrence records globally, of which 8,319,689 (99%) are publicly available. The records are attributed to the corresponding drainage basin and sub-catchment based on the Hydrography90m dataset and are accompanied by the elevation value, the freshwater ecoregion and the protection status of their location. Spatial location and grain: The database covers the global extent, with 86% of the observation records having coordinates with at least four decimal digits (11.1 m precision at the equator) in the World Geodetic System 1984 (WGS84) coordinate reference system. Time period and grain: Sampling years span from 1951 to 2021. Ninety-nine percent of the records have information on the year of the observation, 95% on the year and month, while 94% have a complete date. In the case of seven sub-datasets, exact dates can be retrieved upon communication with the data contributors.Major taxa and level of measurement: Ephemeroptera, Plecoptera, Trichoptera and Odonata, standardized at the genus taxonomic level. We provide species names for 7,727,980 (93%) records without further taxonomic verification. Software format: The entire tab-separated value (.csv) database can be downloaded and visualized at https://glowa bio.org/proje ct/epto_datab ase/. Fifty individual datasets are also available at https://fred.igb-berlin. de, while six datasets have restricted access. For the latter, we share metadata and the contact details of the authors

Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017

A double burden of malnutrition occurs when individuals, household members or communities experience both undernutrition and overweight. Here, we show geospatial estimates of overweight and wasting prevalence among children under 5 years of age in 105 low- and middle-income countries (LMICs) from 2000 to 2017 and aggregate these to policy-relevant administrative units. Wasting decreased overall across LMICs between 2000 and 2017, from 8.4% (62.3 (55.1–70.8) million) to 6.4% (58.3 (47.6–70.7) million), but is predicted to remain above the World Health Organization’s Global Nutrition Target of <5% in over half of LMICs by 2025. Prevalence of overweight increased from 5.2% (30 (22.8–38.5) million) in 2000 to 6.0% (55.5 (44.8–67.9) million) children aged under 5 years in 2017. Areas most affected by double burden of malnutrition were located in Indonesia, Thailand, southeastern China, Botswana, Cameroon and central Nigeria. Our estimates provide a new perspective to researchers, policy makers and public health agencies in their efforts to address this global childhood syndemic

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

Freshwater insects of different feeding guilds ingest microplastics in two Gulf of Guinea tributaries in Nigeria

Plastic pollution has enormous impacts on freshwater and marine ecosystem health, and it is one of the topmost environmental concerns of the current geological period (i.e. the Anthropocene). Thus, the goal of our study was to provide baseline information and bridge the information gap on the occurrence of microplastics (MPs) in African freshwater systems, using two tributaries of the Gulf of Guinea (Ogun and Osun Rivers) in Nigeria as a case study and three freshwater insect species of different feeding guilds as bioindicators. A total of 29 individuals of the insect species were chemically digested and subsequently analysed for MP presence under a digital microscope and a micro-Fourier-transform infrared (μFTIR) spectroscope. Collector-gatherers (Chironomus sp. and Siphlonurus sp.) recorded the highest MP load per gram wet weight, while the predatory Lestes viridis recorded the lowest. The highest diversity of polymers was recorded in Chironomus sp. of Ogun River, i.e. styrene ethylene butylene styrene, acrylonitrile butadiene styrene (ABS), chlorinated polyethylene, polypropylene (PP), and polyester, while two polymers each were recorded in Siphlonurus sp. (i.e. polyester and ABS) and L. viridis (i.e. polyester and PP) of Osun River. We conclude that collector-gatherers like Chironomus sp. and Siphlonurus sp. could be best employed as MP bioindicators in freshwater systems. However, their suitability as MP bioindicators should be further investigated in different freshwater ecosystems worldwide. Graphical abstrac

Assessment of two persistent bioaccumulative toxicants in the UNESCO protected river of Osun-Osogbo, Nigeria

Abstract Introduction Osun River dissecting the Osun-Osogbo Sacred Grove, though inscribed on the World Heritage List, has been rarely assessed for biodiversity values or ecotoxicology. In this study, we investigated the concentrations of Cu and Zn in the benthic sediments and two dominant gastropod species (Melanoides tuberculata and Lanistes varicus) of the Osun River. Benthic sediment and gastropod samples were collected on quarterly basis from June 2015 to March 2016 along the longitudinal stretch of the river. Dry samples were digested and analysed for Cu and Zn using the atomic absorption spectrophotometry. Results With the exception of September sampling period, the two metals recorded higher values in the animals than in the sediments. Cu (1.23 ± 0.81 μg/g) was much lower (p < 0.01) than zinc (6.29 ± 2.15 μg/g) in the benthic sediments. In the same vein, Cu was significantly lower (p < 0.01) than Zn in both species. Both metals recorded much lower values than their average concentrations in the Earth’s crust as well as the recommended limits for freshwater life. Comparatively, L. varicus recorded higher bioaccumulation factor than M. tuberculata. Conclusions Findings from this study suggest that both metals posed no toxicological risk to the freshwater system of Osun River. Concentrations of both metals in the sediments as well as their accumulation factors in both gastropod species were indicative of an unimpacted freshwater system