Hidden in the gut: burden and regional variations of intestinal parasitic infections among Ghanaian children- systematic review and meta-analysis

Abstract

Background

Intestinal parasitic infections (IPIs) are among the most common infections affecting children in low- and middle-income countries, particularly in sub-Saharan Africa.

Aim

This study aimed to systematically review and meta-analyze existing literature on the prevalence and types of intestinal parasitic infections among children in Ghana.

Methodology

Available articles were systematically retrieved on the prevalence and types of intestinal parasitic infection following database searches using PubMed/Medline, Google Scholar African Journal Online, and Science Direct between 2010 and 2025. Two authors independently extracted all relevant data using a standardized Microsoft Excel data extraction form. The PRISMA framework guided the review, and a random-effects model was employed for meta-analysis using R software (version 4.5.0). Heterogeneity (I²) and publication bias (Egger’s test) were assessed. P < 0.050 was considered statistically significant.

Results

Sixteen studies (16) conducted between 2010 and 2019 across various Ghanaian regions were included, with a total sample size ranging from 140 to 884 children. The overall pooled prevalence of intestinal parasitic infections among children in Ghana was 22% (95% CI: 12%–34%), with substantial regional variation, highest in Brong Ahafo/Upper East (40%) and lowest in Greater Accra (9%). Common parasites included Hookworm (14%), Giardia intestinalis (12%), Schistosoma mansoni (8%), Ascaris lumbricoides (4%), and Strongyloides stercoralis (2%), with high heterogeneity across studies (I² >98%). Sensitivity analysis confirmed robustness of prevalence estimates, while funnel plot asymmetry suggested potential publication bias.

Conclusion

Intestinal parasitic infections remain a significant burden among Ghanaian children, particularly in rural and under-resourced regions. The findings emphasize the need for region-specific deworming campaigns, improved sanitation, and routine parasitological screening to reduce the burden and health impact of these infections in early childhood.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-025-11939-7.

Authors.

Introduction

Intestinal parasitic infections (IPIs) are infections of the human gastrointestinal tract caused by various parasites, including helminths and protozoa [1]. Among primary school children, IPIs contribute to numerous adverse outcomes, particularly impairing physical growth and cognitive development [2]. Risk factors include low socioeconomic status, unsafe drinking water, limited awareness of health-promoting behaviors, and poor personal hygiene [3]. Common causative parasites include Ascaris lumbricoides, Trichuris trichiura, Hookworms, and protozoans, which together contribute to reduced physical health and compromised intellectual potential in growing children [3].

According to the World Health Organization (WHO), over one billion people are affected by soil-transmitted helminth infections globally, with school-aged children constituting the majority. In Africa, IPIs rank as the second leading cause of mortality among children under six years of age [4]. Studies in India and Mexico reported high IPI prevalence, 71.8% and 57%, respectively, particularly among children from low-income households, large families, and low parental literacy backgrounds [5, 6]. Moreover, children with multiple parasitic infections (polyparasitism) tend to experience worse cognitive outcomes and higher mortality, as well as increased susceptibility to other infections [7].

Beyond mortality and morbidity, IPIs may also lead to complications such as asthma, diarrhea, anaemia, nervousness, malabsorption, and weakened immunity [8]. Transmission occurs directly through contaminated hands or indirectly via food, utensils, and water. Notably, is the fact that soil-transmitted helminths are strongly associated with open defecation near water sources, where children are especially vulnerable due to play behaviors and water collection practices [9].

Evidence from Forson et al. [10]. highlights key interventions, including improved hygiene practices, socioeconomic development, and greater awareness of IPIs to mitigate the burden of infection among children. However, existing studies on IPIs in Ghana are fragmented, geographically limited, and vary in methodology, making it difficult to develop a comprehensive national perspective. This lack of consolidated data hampers effective policy development, resource allocation, and implementation of targeted interventions. This meta-analysis aimed to fill this knowledge gap by providing a pooled estimate of prevalence and identifying the most frequently reported intestinal parasites, thereby informing public health decision-making and guiding future research and control programs.

Materials and methods

Study design

This systematic review and Meta-analysis followed the 2020 guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement [11].

Information sources and search strategy

The search approach was adapted from Assemie et al. [12] and modified to improve upon search. A comprehensive search was conducted across four databases: PubMed/MEDLINE, Google Scholar, ScienceDirect, and African Journals Online (AJOL) for studies published between 2010 and 2025. Key terms included “intestinal parasite infection,” “prevalence,” “risk factors,” and “children,” combined with “Ghana” using Boolean operators and MeSH terms where applicable. For example, the PubMed search used combinations such as: (“Intestinal Parasite Infection” OR “IPI” OR “Schistosoma species” OR “Giardia species” OR “Hookworm” OR “Trichuris trichiura” OR “Taenia species” OR “Strongyloides stercoralis” OR “Hymenolepis nana” OR “Cyclospora cayetanensis” OR “Entamoeba species” OR “Taenia species” OR “Cryptosporidium species” OR “soil-transmitted helminth” OR “soil-transmitted protozoa” OR “enteroparasitism”) AND (prevalence OR burden) AND (children) AND (Ghana). Similar strategies were tailored for the other databases. To enhance completeness, we manually screened the reference lists of the included studies. Retrieved articles were imported into Zotero (version 7), where duplicates were removed. Screening was performed in three stages: title, abstract, and full-text review, based on predefined eligibility criteria. While the study was not registered, a detailed protocol was developed in advance and strictly followed without deviations.

Eligibility criteria

Studies conducted in Ghana between 2010 and 2025 that reported the prevalence of at least one intestinal parasitic infection (IPI) among children were included. Case reports, review articles, and studies without full-text access despite at least two attempts to contact the primary authors were excluded, as full access was necessary for quality assessment.

Data extraction

Data extraction was carried out independently by two reviewers using a standardized data extraction Excel sheet (K.A., M.J.), which was then cross-checked by two additional reviewers (P.K.K., R.V.D). The extracted data included the following: last name of the first author, publication year, study period, type of study, region, residence (rural vs. urban), total sample size, prevalence and types of IPI, and study site.

Risk of bias assessment

The risk of bias of the studies was assessed using the Newcastle Ottawa quality assessment scale for cross-sectional and cohort studies. Two reviewers independently (K.A. and M.J.) evaluated the included studies based on the tool above, and P.K.K. and R.V.D. resolved any discrepancies. Three dimensions of quality were assessed: Selection, comparability, and Outcome/Exposure, with a total score of 11. Good quality: 3 or 4 stars in selection domain AND 1 or 2 stars in comparability domain AND 2 or 3 stars in outcome/exposure domain Fair quality: 2 stars in selection domain AND 1 or 2 stars in comparability domain AND 2 or 3 stars in outcome/exposure domain Poor quality: 0 or 1 star in selection domain OR 0 stars in comparability domain OR 0 or 1 stars in outcome/exposure domain [13]. The assessment of the articles included is seen in Table 1.

Table 1.

Risk of bias assessment of studies included

Authors	Selection				Comparability	Outcome /Exposure			Total Score
	Item 1	Item 2	Item 3	Item 4	Item 1	Item 1	Item 2	Item 3
Cosmos & John [14)	*	*		**		**	*		7
Anim-Baidoo et al. [15)	*	*		*	*	**	*		7
Abaka-Yawson et al. [16)	*	*	*			**	*		6
Ofosu&Ako-Nnubeng [17)	*					**	*		4
Tandoh et al. [18)	*			*	*	**	*		6
Sam et al. [19)	*		*	*		**	*		7
Orish et al. [20)	*	*		*		**	*		7
Mirisho et al. [21)	*		*	*	*	**	*		7
Kpene et al. [22)	*		*	*	*	**	*		7
Humphries et al. [23)	*			**	*	**	*		7
Humphries et al. [24)	*	*	*			**	*		6
Forson et al. [25)	*		*	*	*	**	*		6
Egbi et al. [26)	*		*		*	**	*		6
Dankwa et al. [27)	*			**	*	**	*		7
Opintan et al. [28)	*	*		*	*	**	*		7
Anim-Baidoo et al. [29)	*	*	*			**	*		6

Study selection

The PRISMA chart illustrates the process of identifying and screening articles for inclusion in a study. Initially, 5,223 records were identified through database searches, with 951 duplicates removed before screening. Following this, 1,570 records were screened based on title and abstract, resulting in 1,305 exclusions. A total of 265 full-text articles were assessed for eligibility, leading to 249 exclusions for various reasons, including 15 editorials, 200 studies conducted outside Ghana, and 3 studies with different study designs. Ultimately, 16 articles met the inclusion criteria and were included in the review (Fig. 1).

Fig. 1.

PRISMA Chart

Statistical analysis

A pooled prevalence of IPI and its types, each with a 95% confidence interval (CI), was calculated using a random effects framework employing the inverse variance method. Sub-group analysis was conducted based on region. Heterogeneity between the studies was assessed using the I-squared (%). The degree of heterogeneity was classified as follows: low (I² = 0–25%), moderate (I² = 26–50%), substantial (I² = 51–75%), and considerable (I² >75%). Sensitivity analysis was performed using the leave-one-out technique to examine the robustness of the results. Publication bias was assessed through a funnel plot and Egger’s regression test. All statistical analyses were performed using R software (version 4.5.0). A p-value below 0.05 was considered indicative of statistical significance. For the assessment of publication bias, a p-value of less than 0.1 from Egger’s test was regarded as evidence of potential publication bias.

Results

Characteristics of studies included

Table 2 reveals the characteristics of 14 studies on intestinal parasitic infections in Ghanaian children. Studies were conducted between 2010 and 2019 across various regions of Ghana (Greater Accra, Ashanti, Volta, Brong Ahafo, etc.) with sample sizes ranging from 140 to 884 participants. Most were cross-sectional designs using various sampling methods (random, systematic, convenience). Participants’ ages ranged from < 6 months to 18 years, with studies conducted in both rural, urban, and mixed settings. Diagnostic techniques varied, with Kato-Katz, formol-ether concentration, and direct wet mount methods being most common.

Table 2.

Characteristics of studies included

Authors (references)	Month of study	Year of study	Type of Study	Sampling type	Sample Size	Age Range	Age Mean (SD)	Study Area	Study Sites	Region	Residence	Technique
Cosmos & John[14)	NA	2015	NA	Systematic	884	NA	NA	Kwabre East	48	Ashanti	NA	Iodine and saline mounts (direct technique) and the formol-ether concentration techniques
Anim-Baidoo et al. [15)	March -June	2010–2013	CS	NA	485	< 6 months − 3 years	NA	Princess Marie Louise Children’s Hospital	1	Greater Accra	Urban	Formol-ether concentration techniques, ELISA and PCR
Abaka-Yawson et al. [16)	November -February	2018–2019	CS	Convenience	152	0–4 years	NA	Dodi Papase	NA	Oti	Mixed	Kato–Katz technique
Ofosu&Ako-Nnubeng [17)			NA	Random	286	NA	NA	Kwahu West	7	Eastern	Rural	Kato–Katz technique
Tandoh et al. [18)	NA	NA	CC	Random	329	5–18 years	10.74 (2.79)	Bongo d istrict	NA	Upper East	Rural	Sedimentation technique and Kato Katz
Sam et al. [19)	October-March	2010–2011	NA	NA	394	5–15 years	NA	Kassena-Nankana East and West Districts	2	Upper East	Rural	Formol ether concentration techniques.
Orish et al. [20)	March- April	2016	CS	NA	550	6–14 years	NA	Ho municipal, Adaklu, and Agotime-Ziope districts	5	Volta	Rural	wet mount method
Mirisho et al. [21)	May - June	2015	CS	consecutive	225	0-10years	NA	Princess Marie Louise Children’s Hospital	1	Greater Accra	Urban	Direct method
Kpene et al. [22)	NA	NA	CS	Simple Random	150	0–4 years	NA	Ho Municipality	5	Volta	Mixed	Direct wet preparation, formol-ether concentration and Modified ZN staining technique
Humphries et al. [23)		NA	NA	Random	140	6–13 years	NA	Kintampo North Municipality	5	Brong Ahafo	Rural	Kato–Katz technique
Humphries et al. [24)	June	2010	NA	Random	812	6–11 years	NA	Kintampo North Municipality	16	Brong Ahafo	Rural	Kato–Katz technique
Forson et al. [25)	March -July	2016	CS	NA	300	2–9 years	NA	Odododiodio constituency	1	Greater Accra	Mixed	Direct wet mount and formol-ether concentration
Egbi et al. [26)	July	2010	CS	Random	143	6–12 years	9.2 (2.3)	Kodzobi	1	Volta	Rural	Kato–Katz technique
Dankwa et al. [27)	February - March	2014	CS	Random	230	6–17 years	NA	Cape Coast metropolis	5	Central	Rural	wet mount and formalin-ether concentration techniques
Opintan et al. [28)	August-May	2007–2008	CS	Convenience	170	< 4	NA	Accra	1	Greater Accra	Urban	PCR
Anim-Baidoo et al. [29)	May-September	2022	CS	Random	262	6-15years	NA	Lantemeame-Chorkor0	1	Greater Accra	Peri-urban	Formol-ether concentration

NA; Not available, CS; Cross-sectional, CC; Case Control

Parasitic infection characteristics among the studies included

The reviewed studies showed considerable variation in the prevalence of intestinal parasites among children in Ghana. Ascaris lumbricoides was reported in up to 64.7% of cases (Ofosu & Ako-Nnubeng, 2014), 39.1% [24], and 20.4% [16]. Schistosoma mansoni showed particularly high prevalence in [18] at 49.5% and [14] at 59.6%. Hookworm prevalence ranged from 1.3% to 7.1%, with the highest in [21]. Strongyloides stercoralis was found in up to 13.2% of children [16], while Giardia intestinalis ranged from 1.0% to 10.8%, peaking in [14]. Trichuris trichiura was identified in a few studies, with a prevalence as high as 5.1% [19]. Parasites reported by only one study included Hymenolepis nana (up to 2.2%), Taenia species (0.3%), Entamoeba histolytica (up to 1.7%), C. parvum (2.94–5.3%), Cyclospora cayetanensis (2.7%), E. coli (13.8%), and amorphous amoebae, 24.8% in [14] (Table 3).

Table 3.

Parasitic infection characteristics among the studies included

Authors (References)	Prevalence N (%)	A. lumbricoides n (%)	Hookworm n (%)	S. stercoralis n (%)	T. trichiura n (%)	E. histolytica n (%)	G. intestinalis n (%)	S. mansoni n (%)	C. parvum n (%)
Cosmos & John [14)	492 (55.7)					77 (8.71)	293 (33.14)
Anim-Baidoo et al. [15)	27 (10.8)						27 (10.8)
Abaka-Yawson et al. [16)	67 (44.1)	31 (20.4)	20 (13.2)		16 (10.5)
Ofosu&Ako-Nnubeng [17)	17 (100.0)	11 (64.7)			4 (23.5)
Tandoh et al. [18)	191 (95.7)							191 (95.7)
Sam et al. [19)	37 (9.39)	4 (1.0)	13 (3.30)	20 (5.08)	0 (0.00)
Orish et al. [20)	13 (6.0)	7 (1.3)	5 (0.91)					1 (0.18)
Mirisho et al. [21)	39 (17.3)	16 (7.1)	23 (10.2)
Kpene et al. [22)	21 (14.0)	2 (1.3)		1 (0.7)		5 (3.3)	1 (0.7)		8 (5.3)
Humphries et al. [23)	82 (59.0)		82 (59.0)
Humphries et al. [24)	286 (39.1)		286 (39.1)
Forson et al. [25)	45 (15.0)	3 (1.0)		1 (0.3)		3 (1.0)	30 (10)	5 (1.7)
Egbi et al. [26)	18 (9.8)		18 (9.8)
Dankwa et al. [27)	44 (19.1)	7 (3.0)	9 (3.9)	4 (1.7)	4 (1.7)		15 (6.5)	5 (2.2)
Opintan et al. [28)	19 (11.17)					5 (2.9)			14 (2.94)
Anim-Baidoo et al. [29)	40 (15.3)	8 (3.05)	5 (1.91)			9 (3.44)	15 (5.73)	3 (1.12)

N = Total number of individuals included in each study; n = Number of individuals infected with the specific parasite

Sensitivity and publication bias of the studies included

Figure 2 shows sensitivity analysis (2a) and publication bias assessment (2b) for intestinal parasitic infections in Ghanaian children. Removing individual studies maintained consistent prevalence estimates (16–20%) with persistent high heterogeneity (I² >98.4%). The asymmetrical funnel plot suggests potential publication bias in the meta-analysis.

Fig. 2.

Sensitivity and publication bias. a; Sensitivity assessment, b; publication bias with Egger’s test

Overall prevalence of parasitic infection among Ghanaian children

Figure 3 shows that the overall prevalence of intestinal parasitic infections (IPI) in Ghanaian children was 18% [0.10–0.28] using a random effects model. High heterogeneity was observed (I² = 99.0%, p < 0.0001), with individual study prevalence ranging from 2% to 59%. The weight distribution across studies was relatively uniform in the random effects model (approximately 6% each).

Fig. 3.

Overall prevalence of parasitic infection among Ghanaian children

Prevalence of types of parasitic infections included studies

Figure 4 shows parasitic infection prevalence in Ghanaian children (random effects models): Hookworm had the highest pooled prevalence at 9% [95% CI: 4%–21%], followed by Giardia intestinalis at 8% [95% CI: 3%–19%], and Cryptosporidium parvum at 7% [95% CI: 5%–10%]. Entamoeba histolytica showed a prevalence of 4% [95% CI: 2%–7%], while Schistosoma mansoni and Ascaris lumbricoides were both at 3%, with CIs of [1%–10%] and [1%–6%], respectively.

Fig. 4.

Prevalence of types of parasitic infections among included studies

Sub-group meta-analysis of parasitic infection among study participants

Figure 5 presents a subgroup meta-analysis of intestinal parasitic infections, categorizing them into helminths and protozoan parasites. The pooled prevalence of helminth infections was 4% [95% CI: 2%–7%], while protozoan infections showed a higher pooled prevalence of 6% [95% CI: 4%–9%]. Substantial heterogeneity was observed within both subgroups (I² = 97.8% for helminths and 98.6% for protozoa), indicating considerable variation across studies. Although the pooled prevalence was higher for protozoa, the difference between the two subgroups was not statistically significant (p = 0.2848).

Fig. 5.

Sub-group meta-analysis of parasitic infection among study participants

Overall prevalence of parasitic infection stratified by region

The results show significant variations, with the highest proportion observed in the Ashanti/Eastern/Central region (0.59, 95% CI [0.50, 0.68]) and the lowest in the Brong Ahafo/Upper East region (0.58, 95% CI [0.37, 0.77]). The heterogeneity tests indicate substantial differences among the studies (I² = 928.81, p < 0.001). (Fig. 6).

Fig. 6.

Overall prevalence of parasitic infection stratified by region

Discussion

Intestinal parasitic infections (IPIs) remain a significant public health concern in many low- and middle-income countries, particularly among children, due to their impact on nutrition, cognitive development, and morbidity [30]. These infections are closely linked to poor sanitation, inadequate hygiene, and limited access to clean water. In Ghana, several studies have assessed the prevalence of IPIs among children; however, findings vary considerably due to differences in study settings, population characteristics, and diagnostic methods.

In the current meta-analysis, based on a random effects model, the overall pooled prevalence of IPIs among Ghanaian children was 18%. Importantly, this estimate should be interpreted as a conservative measure of disease burden, as heterogeneity in pathogen coverage across studies, with no single study capturing all target parasites, likely results in underestimation of true cumulative prevalence. Substantial heterogeneity was observed across studies (I² = 99.0%, p < 0.0001), with 2% to 59% prevalence. This variation likely reflects differing diagnostic methods, age ranges, and socio-environmental conditions. For example, Cosmos & John [14] reported a prevalence of 59.6% in a rural setting with inadequate sanitation, while Orish et al. [20] found a much lower prevalence (2%) in an urban hospital-based study. The pooled prevalence reported in this meta-analysis is notably lower than the 46.1% reported in a similar national-level meta-analysis from Ethiopia [12], South Africa (43%) [31] and the Eastern region of Nepal (31.5%) [32], highlighting possible disparities in environmental sanitation, access to clean water, healthcare infrastructure, and the implementation of public health interventions between the two countries. This estimate is, however, comparable to prevalence rates observed in individual studies from other African countries, such as those reported in parts of Iran, including Northwestern Iran (10.6%) [33] and Tehran (18.4%) [34]. Beyond overall prevalence, our subgroup analysis revealed distinct patterns; protozoan infections (6%) were more common than helminths (4%)), though this difference was not statistically significant (p = 0.2848). This suggests protozoa may contribute disproportionately to Ghana’s IPI burden, warranting targeted surveillance. Meanwhile, these variations may reflect differences in diagnostic approaches, deworming coverage, study settings (urban vs. rural), and seasonal transmission patterns. Diagnostic techniques also influence prevalence estimates. Studies that utilize more sensitive diagnostic tools, such as polymerase chain reaction (PCR), Kato-Katz, or multiple stool examinations, tend to report higher prevalence rates than those relying solely on a single wet mount preparation [35]. Age and seasonal variation also play roles, with younger children and rainy seasons often associated with increased infection risk [30]. While our meta-analysis suggests a moderate IPI burden among Ghanaian children, the observed variability in prevalence reflects important regional, methodological, and infrastructural differences.

Subsequently, it was observed that the findings of Dahal et al. [36] complement our study, identifying Ascaris lumbricoides as the most prevalent soil-transmitted helminth (STH) in their cohort (25.7%), followed by Trichuris trichiura (10.3%). In contrast, hookworm was reported less frequently (5.1%), while Strongyloides stercoralis accounted for a minor proportion (1.5%). Unlike their results, which emphasized the dominance of A. lumbricoides, our analysis revealed hookworm as the most prevalent STH (14%) among Ghanaian children. Furthermore, Sah et al. [32]. reported a protozoan infection rate of 18.5%, which exceeds the 12% prevalence of Giardia intestinalis observed in our meta-analysis. These differences highlight potential regional and environmental variations in intestinal parasite distribution and underscore the importance of localized surveillance in informing control strategies.

This study highlights significant regional variation in intestinal parasitic infection (IPI) prevalence among Ghanaian children, with the highest rates observed in the Brong Ahafo/Upper East (40%) and Ashanti/Eastern/Central regions (24%), and the lowest in Greater Accra (9%). These disparities likely reflect differences in sanitation, water access, hygiene practices, and healthcare availability. To address this burden, region-specific public health interventions, such as intensified mass deworming campaigns, improved water, sanitation, and hygiene (WASH) infrastructure, and integration of parasite control into school health programs, are essential. Targeted efforts in high-burden regions will be critical to reducing infections and improving child health outcomes nationally.

This study is limited by heterogeneity in diagnostic methods, variation in pathogen coverage across studies, and small sample sizes in some included articles. Not all studies screened for the full range of intestinal parasites, which may have led to an underestimation of the overall prevalence. Additionally, some studies used multiple diagnostic methods without clear reporting of overlapping positive cases, which initially introduced inconsistencies in prevalence estimates. We have addressed these issues by standardizing prevalence calculations and prioritizing data from the most sensitive diagnostic method where applicable. Nevertheless, reliance on single-time stool examinations in most studies may still underestimate the true burden. The lack of age-specific prevalence breakdowns also limits subgroup analyses. Finally, terminology variation across studies may have affected search sensitivity, even after expanding the search strategy to include pathogen-specific terms.

Conclusion

Intestinal parasitic infections, particularly hookworm and protozoan infections, remain a significant public health issue among Ghanaian children. Routine parasitological screening and deworming should be incorporated into school health programs, especially in high-prevalence regions, to mitigate the health burden. Clinicians must be alert to underdiagnosed protozoan infections, which contribute to gastrointestinal and nutritional morbidity. A new hypothesis suggests that the higher prevalence of hookworm over Ascaris lumbricoides may be linked to region-specific soil types and sanitation conditions, which could influence transmission patterns. Further research into these environmental factors is essential to better understand the epidemiology and improve intervention strategies.

Recommendations

Future research should adopt standardized, sensitive diagnostic protocols and explore environmental and behavioural correlates of infection. Policymakers should strengthen regional parasitic control efforts through community-based WASH interventions, school-based deworming, and surveillance systems tailored to local transmission dynamics.

Supplementary Information

Below is the link to the electronic supplementary material.

Author contributions

The study was conceptualized by KA, with the methodology developed by RVD, MJ, and IB. Formal analysis was conducted by KA, AAY and PKK. Data curation was performed by MJ, IB, and BDK. The original draft was written by KA, MJ, and BDK, while review, editing, and supervision were carried out by AAY, RVD and PKK.

Funding

The authors received no external funding for this work.

Data availability

All relevant data will be made available upon request from corresponding author.

Declarations

Ethical approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.