Prevalence and genotypic characterization of Giardia duodenalis isolates from asymptomatic school-going children in Lusaka, Zambia

Tembo, Shadreck; Mutengo, Mable; Sitali, Lungowe; Changula, Katendi; Takada, Ayato; Mweene, Aaron S.; Simulundu, Edgar; Chitanga, Simbarashe

doi:10.1016/j.fawpar.2020.e00072

Cited by 15 publications

(16 citation statements)

References 46 publications

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“…(2012) ; Kashinahanji et al. (2019) ; Tembo et al. (2020) Secondary: GDHiF Secondary: GDHiR CAGTACAACTCYGCTCTCGG GTTRTCCTTGCACATCTCC 432 RE: BspL I ( NIa IV) and Rsa I – – gdh Nested PCR and sequencing Primary: Gdh1 Primary: Gdh2 TTCCGTRTYCAGTACAACTC ACCTCGTTCTGRGTGGCGCA 754 A (AI, AII, AIII) & B (BIII, BIV) Cacciò et al.…”

Section: Molecular Tools For Genetic Characterisation Of G ...mentioning

confidence: 99%

The controversies surrounding Giardia intestinalis assemblages A and B

Zajaczkowski

Lee

Fletcher-Lartey

et al. 2021

Current Research in Parasitology & Vector-Borne Diseases

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Section: Molecular Tools For Genetic Characterisation Of G ...mentioning

confidence: 99%

The controversies surrounding Giardia intestinalis assemblages A and B

Zajaczkowski

Lee

Fletcher-Lartey

et al. 2021

Current Research in Parasitology & Vector-Borne Diseases

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“…In children in endemic regions, early-life infections by G. duodenalis have been associated with stunting (low height for age), wasting (low weight for height), and impaired cognitive function [8][9][10]. However, asymptomatic infections in African children have been commonly reported in several sub-Saharan countries [11][12][13][14][15]. Progression from infection to disease is a multifactorial process involving both host (age, immune and nutritional status, microbiota composition and abundance) and pathogen (burden, genotype, virulence, immunomodulatory potential) determinants whose interactions and exact contribution to the tilting of the health-disease balance are not completely understood [16,17].…”

Section: Introductionmentioning

confidence: 99%

Molecular diversity of Giardia duodenalis in children under 5 years from the Manhiça district, Southern Mozambique enrolled in a matched case-control study on the aetiology of diarrhoea

Messa

Köster²,

Garrine

et al. 2021

PLoS Negl Trop Dis

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Giardia duodenalis is an enteric parasite commonly detected in children. Exposure to this organism may lead to asymptomatic or symptomatic infection. Additionally, early-life infections by this protozoan have been associated with impaired growth and cognitive function in poor resource settings. The Global Enteric Multicenter Study (GEMS) in Mozambique demonstrated that G. duodenalis was more frequent among controls than in diarrhoeal cases (≥3 loosing stools in the previous 24 hours). However, no molecular investigation was conducted to ascertain the molecular variability of the parasite. Therefore, we describe here the frequency and genetic diversity of G. duodenalis infections in children younger than five years of age with and without diarrhoea from the Manhiça district in southern Mozambique enrolled in the context of GEMS. Genomic DNA from 757 G. duodenalis-positive stool samples by immunoassay collected between 2007–2012, were reanalysed by multiplex PCR targeting the E1-HP and C1-P21 genes for the differentiation of assemblages A and B. Overall, 47% (353) of the samples were successfully amplified in at least one locus. Assemblage B accounted for 90% (319/353) of all positives, followed by assemblage A (8%, 29/353) and mixed A+B infections (1%, 5/353). No association between the presence of a given assemblage and the occurrence of diarrhoea could be demonstrated. A total of 351 samples were further analysed by a multi-locus sequence genotyping (MLSG) approach at the glutamate dehydrogenase (gdh), ß-giardin (bg) and triose phosphate isomerase (tpi) genes. Overall, 63% (222/351) of samples were genotyped and/or sub-genotyped in at least one of the three markers. Sequence analysis revealed the presence of assemblages A (10%; 23/222) and B (90%; 199/222) with high molecular diversity at the nucleotide level within the latter; no mixed infections were identified under the MLSG scheme. Assemblage A sequences were assigned to sub-assemblages AI (0.5%, 1/222), AII (7%, 15/222) or ambiguous AII/AIII (3%, 7/222). Within assemblage B, sequences were assigned to sub-assemblages BIII (13%, 28/222), BIV (14%, 31/222) and ambiguous BIII/BIV (59%, 132/222). BIII/BIV sequences accumulated the majority of the single nucleotide polymorphisms detected, particularly in the form of double peaks at chromatogram inspection. This study demonstrated that the occurrence of gastrointestinal illness (diarrhoea) was not associated to a given genotype of G. duodenalis in Mozambican children younger than five years of age. The assemblage B of the parasite was responsible for nine out of ten infections detected in this paediatric population. The extremely high genetic diversity observed within assemblage B isolates was compatible with an hyperendemic epidemiological scenario where infections and reinfections were common. The obtained molecular data may be indicative of high coinfection rates by different G. duodenalis assemblages/sub-assemblages and/or genetic recombination events, although the exact contribution of both mechanisms to the genetic diversity of the parasite remains unknown.

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confidence: 99%

“…The final two research articles address, respectively, asymptomatic Giardia infection in school children in Lusaka, Zambia ( Tembo et al, 2020 ; this issue) and contamination of drinking water with Cryptosporidium and Giardia from different sources (protected or non-protected) in Tigray, Ethiopia ( Kifleyohannes and Robertson, 2020 ; this issue). The work from Zambia indicated a prevalence of asymptomatic infections of around 10%, as detected by molecular analyses, indicating that anthroponotic transmission was predominant, although other likely vehicles of infection were not investigated ( Tembo et al, 2020 ). The work from Ethiopia that focussed specifically on a potential transmission vehicle found that contamination of drinking water sources with Cryptosporidium oocysts was not extensive (5% of samples positive, all with low numbers of oocysts), and 16% of samples were contaminated with Giardia cysts, with numbers of cysts being as high as 22 cysts per 10 L ( Kifleyohannes and Robertson, 2020 ).…”

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confidence: 99%

“…Provision of adequately treated drinking water and protection of water sources from contamination with human sewage should be an area of focus (SDG #6). The report by Tembo et al (2020) on a relatively high prevalence of asymptomatic infections highlights a potential source of contamination of the environment and, ultimately, infection of vulnerable members in the communities.…”

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Food and waterborne parasites in Africa - threats and opportunities

Robertson

Chitanga

Mukaratirwa

2020

Food and Waterborne Parasitology

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This Special Issue (SI) was conceptualized on the basis that success in tackling foodborne and waterborne parasites (FBP and WBP) will contribute to achievement of seven of the United Nation's Sustainable Development Goals (SDGs). We chose to take a closer look at research on FBP and WBP in Africa, given that attaining these SDGs may be particularly challenging there. In this SI we present 7 articles that provide particular insights into FBP and WBP from different regions in Africa. The articles take different approaches. Three papers are reviews addressing “occurrence” (either widely, in terms of parasite and/or geography, or with focus on a specific parasite genus at a more regional level); all 3 articles emphasise the importance of a “One Health” approach regarding control and prevention of FBP and WBP, and the need for further research to fulfil the information gaps identified. Two articles then report on investigations regarding the knowledge and understanding of different communities in Africa regarding various FBP and WBP. These articles highlight lack of awareness among communities at risk, and also, perhaps of greater relevance, gaps in the knowledge of health workers regarding some FBP and WBP of public health importance. The final two articles are research articles regarding prevalence and occurrence of specific WBP, both as infections and in the environment. This SI, while limited in depth and scope, provides insights into some of the current challenges associated with FBP and WBP in Africa that might result in a lack of success regarding attainment of the previously mentioned seven SDGs. We anticipate significant advances in research on FBP and WBP in Africa, and hope that a future SI on the same topic may present a more positive picture regarding the current status and research achievements.

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Prevalence and genotypic characterization of Giardia duodenalis isolates from asymptomatic school-going children in Lusaka, Zambia

Cited by 15 publications

References 46 publications

The controversies surrounding Giardia intestinalis assemblages A and B

The controversies surrounding Giardia intestinalis assemblages A and B

Molecular diversity of Giardia duodenalis in children under 5 years from the Manhiça district, Southern Mozambique enrolled in a matched case-control study on the aetiology of diarrhoea

Food and waterborne parasites in Africa - threats and opportunities

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