Prevalence and distribution pattern of malaria and soil-transmitted helminth co-endemicity in sub-Saharan Africa, 2000-2018: A geospatial analysis.

BACKGROUND: Limited understanding exists about the interactions between malaria and soil-transmitted helminths (STH), their potential geographical overlap and the factors driving it. This study characterised the geographical and co-clustered distribution patterns of malaria and STH infections among vulnerable populations in sub-Saharan Africa (SSA). METHODOLOGY/PRINCIPAL FINDINGS: We obtained continuous estimates of malaria prevalence from the Malaria Atlas Project (MAP) and STH prevalence surveys from the WHO-driven Expanded Special Project for the Elimination of NTDs (ESPEN) from Jan 1, 2000, to Dec 31, 2018. Although, MAP provides datasets on the estimated prevalence of Plasmodium falciparum at 5km x 5km fine-scale resolution, we calculated the population-weighted prevalence of malaria for each implementation unit to ensure that both malaria and STH datasets were on the same spatial resolution. We incorporated survey data from 5,935 implementation units for STH prevalence and conducted the prevalence point estimates before and after 2003. We used the bivariate local indicator of spatial association (LISA analysis) to explore potential co-clustering of both diseases at the implementation unit levels among children aged 2-10 years for P. falciparum and 5-14 years for STH, living in SSA. Our analysis shows that prior to 2003, a greater number of SSA countries had a high prevalence of co-endemicity with P.falciparium and any STH species than during the period from 2003-2018. Similar prevalence and distribution patterns were observed for the co-endemicity involving P.falciparum-hookworm, P.falciparum-Ascaris lumbricoides and P.falciparum-Trichuris trichiura, before and after 2003. We also observed spatial variations in the estimates of the prevalence of P. falciparum-STH co-endemicity and identified hotspots across many countries in SSA with inter-and intra-country variations. High P. falciparum and high hookworm co-endemicity was more prevalent in West and Central Africa, whereas high P. falciparum with high A. lumbricoides and high P. falciparum with high T. trichiura co-endemicity were more predominant in Central Africa, compared to other sub-regions in SSA. CONCLUSIONS/SIGNIFICANCE: Wide spatial heterogeneity exists in the prevalence of malaria and STH co-endemicity within the regions and within countries in SSA. The geographical overlap and spatial co-existence of malaria and STH could be exploited to achieve effective control and elimination agendas through the integration of the vertical control programmes designed for malaria and STH into a more comprehensive and sustainable community-based paradigm

Left ventricular geometric patterns in newly presenting nigerian hypertensives: An echocardiographic study

Abstract Background Hypertension is a global problem and it is prevalent in Nigeria. Left ventricular hypertrophy is a major complication of hypertension with risk of sudden death and arrhythmias among others. Abnormal left ventricular geometric patterns also increase the burden of morbidity and mortality. It is therefore important to know the different left ventricular geometric patterns in Nigerian hypertensives because of their prognostic significance. Methods One hundred (100) newly presenting hypertensives (53 males and 47 females) and 100 controls (53 males and 47 females) were recruited for the study. All were subjected to clinical evaluation and full echocardiographic examination was performed according to the ASE recommendation. The relative wall thickness and the presence or absence of echocardiographic left ventricular hypertrophy were used to determine the various geometric patterns Results The mean age of the hypertensive subjects was 56.06 (± 7.68) years while that of the control subjects was 56.10 (± 7.68) years. There was no significant difference in the mean ages of the two groups. In the hypertensive subjects 28% had normal geometry, 26% had concentric remodeling, 28% had concentric hypertrophy and 18% had eccentric hypertrophy. In the control group, 86% had normal geometry, 11% had concentric remodeling, 3% had eccentric hypertrophy and none had concentric hypertrophy. There was statistical significance when the geometric patterns of the hypertensive and controls were compared (χ2 = 74.30, p value Conclusion The study showed that only 28% of the hypertensive subjects had normal LV geometric pattern while 86% of the normal subjects had normal geometry. There is need for longitudinal studies in order to prognosticate the various geometric patterns.</p

Summary table of STH prevalence estimates by country and frequency of prevalence surveys per country, sub-Saharan Africa, 2000–2018.

(DOCX)</p

Moran’s I statistic plot showing spatial auto-correlation for <i>P</i>. <i>falciparum</i> vs any soil-transmitted helminth co-endemicity in sub-Saharan Africa, pre-2003 and 2003–2018.

(TIF)</p

The prevalence of P. falciparum and soil-transmitted helminth (Hookworm, <i>Ascaris lumbricoides</i>, <i>Trichiuris trichiura</i>) co-endemicity, and their corresponding significant hotspots locations (ADM1, ADM2, and ADM3) in sub-Saharan Africa, pre-2003 and 2003–2018.

(DOCX)</p

The prevalence of <i>P</i>. <i>falciparum</i> and hookworm co-endemicity, and significant hotspots of <i>P</i>.<i>falciparum</i> and hookworm co-endemicity in sub-Saharan Africa.

’The density description next to the colour coded box refers to the prevalence of P. falciparum, whilst the column further to the right refers to density of hookworm. Link to the base layer of the map: https://gadm.org/index.html.</p

Summary table of <i>P</i>.<i>falciparum</i> prevalence estimates by country and frequency of prevalence surveys per country, sub-Saharan Africa, 2000–2018.

(DOCX)</p

Moran’s I statistic plot showing spatial auto-correlation for <i>P</i>. <i>falciparum</i> vs <i>T</i>.<i>trichiura</i> co-endemicity in sub-Saharan Africa, pre-2003 and 2003–2018.

(TIF)</p

Moran’s I statistic plot showing spatial auto-correlation for <i>P</i>. <i>falciparum</i> vs <i>Ascaris lumbricoides</i> co-endemicity in sub-Saharan Africa, pre-2003 and 2003–2018.

(TIF)</p

The prevalence of <i>P</i>. <i>falciparum</i> and <i>Ascaris lumbricoides</i>, and significant hotspots of <i>P</i>. <i>falciparum</i> and <i>A</i>.<i>lumbricoides</i> co-endemicity in sub-Saharan Africa.

The density description next to the colour-coded box refers, to the prevalence of P. falciparum whilst the column further to the right refers to density of A. lumbricoides. Link to the base layer of the map: https://gadm.org/index.html.</p