High Prevalence of Urinary Schistosomiasis in a Desert Population: Results from an Exploratory Study Around the Ounianga Lakes in Chad

2021 ◽  
Author(s):  
Wendelin Moser ◽  
Annour Aboum Batil ◽  
Rebekka Ott ◽  
Moussa Abderamane ◽  
Ruth Clements ◽  
...  
Keyword(s):  
Intermediate Host ◽  
Exploratory Study ◽  
Health Concern ◽  
Human Populations ◽  
Sahara Desert ◽  
Urinary Schistosomiasis ◽  
Host Snail ◽  
Bulinus Truncatus ◽  
High Prevalence ◽  
Trematode Parasites

Abstract Background: Researching a water-borne disease in the middle of the Sahara desert might not seem the most relevant concern. However, nomadic Sahelian pastoralist’s health concerns regarding their livestock and anecdotal reports about trematode infections of Fasciola spp and Schistosoma spp in desert-raised animals justified an exploratory study focusing on the lakes of Ounianga in Northern Chad. The aim was to test whether trematode parasites such as Schistosoma spp occur in human populations living around the Sahara desert lakes of Ounianga Kebir and Ounianga Saker in northern Chad. Methods: The study comprised of three components. First, a cross sectional survey based on a random sample drawn from the population to detect infections with S. haematobium and S. mansoni ; second, focus group discussions exploring disease priorities, access to health and health seeking behaviour; and third, searching water contact sites for intermediate host snails. Samples of trematode parasites and snails were confirmed on species level by molecular genetics methods. Results: Among 258 participants, the overall S. haematobium prevalence using urine filtration was 39.1% (95% CI 33.2% – 45.1%), with 51.5% of the infected suffering from heavy infection. The intermediate host snail of S. haematobium ( Bulinus truncatus ) occurred at water sites near both study villages, revealing the potential for local transmission. Although a positive S. mansoni POC-CCA test result was obtained from 15.2% (10.6%-19.7%) of the samples no intermediate host snails of S. mansoni were found, and the relevance of S. mansoni remains uncertain. Qualitative findings underline the importance of morbidity caused by urinary schistosomiasis, and the lack of access to diagnostics and treatment as a major health concern. Conclusion: This research revealed a high prevalence of urinary schistosomiasis in the population living around the lakes of Ounianga in the Sahara, a UNESCO world heritage site in Chad. Despite the high public health importance of the associated morbidity expressed by the population there is no access to diagnostics and treatment. Further research is needed to develop and test a context adapted intervention.

scholarly journals High prevalence of urinary schistosomiasis in a desert population: results from an exploratory study around the Ounianga lakes in Chad

2022 ◽  
Vol 11 (1) ◽  
Author(s):  
Wendelin Moser ◽  
Annour Adoum Batil ◽  
Rebekka Ott ◽  
Moussa Abderamane ◽  
Ruth Clements ◽  
...  
Keyword(s):  
Intermediate Host ◽  
Exploratory Study ◽  
Health Concern ◽  
Sahara Desert ◽  
Water Contact ◽  
Urinary Schistosomiasis ◽  
Bulinus Truncatus ◽  
Contact Sites ◽  
High Prevalence ◽  
Trematode Parasites

Abstract Background Researching a water-borne disease in the middle of the Sahara desert might not seem the most relevant concern. However, nomadic Sahelian pastoralists health concerns regarding their livestock and anecdotal reports about trematode infections of Fasciola spp. and Schistosoma spp. in desert-raised animals justified an exploratory study focusing on the lakes of Ounianga in Northern Chad. The aim was to test whether trematode parasites such as Schistosoma spp. occur in human populations living around the Sahara desert lakes of Ounianga Kebir and Ounianga Serir in northern Chad. Methods The study was carried out in January 2019 and comprised of three components. First, a cross sectional survey based on a random sample drawn from the population to detect infections with S. haematobium and S. mansoni; second, focus group discussions exploring disease priorities, access to health and health seeking behaviour; and third, surveying water contact sites for intermediate host snails. Samples of trematode parasites and snails were confirmed on species level by molecular genetic methods. For parasitological and malacological surveys descriptive statistics were performed. Qualitative data analysis included the full review of all transcripts, followed by a descriptive and explorative thematic analysis. Results Among 258 participants, the overall S. haematobium prevalence using urine filtration was 39.2% [95% confidence interval (CI): 33.5–45.1%], with 51.5% of the infected suffering from heavy infection. The intermediate host snail of S. haematobium (Bulinus truncatus) occurred at water contact sites near both study villages, revealing the potential for local transmission. Although a positive S. mansoni point-of-care circulating cathodic antigen (POC-CCA) test result was obtained from 8.6% (95% CI 5.7–12.8%) of the samples, no intermediate host snails of S. mansoni were found, and the relevance of S. mansoni remains uncertain. Qualitative findings underline the importance of morbidity caused by urinary schistosomiasis, and the lack of access to diagnostics and treatment as a major health concern. Conclusions This research revealed a high prevalence of urinary schistosomiasis in the population living around the lakes of Ounianga in the Sahara, a United Nations Educational, Scientific and Cultural Organization (UNESCO) world heritage site in Chad. Despite the high public health importance of the associated morbidity expressed by the population, there is no access to diagnostics and treatment. Further work is needed to develop and test a context-adapted intervention. Graphical Abstract

scholarly journals Use of Nicotiana tobaccum extractions as a molluscicide to the snail of Bulinus truncates

2009 ◽  
Vol 6 (2) ◽  
pp. 298-301
Author(s):  
Baghdad Science Journal
Keyword(s):  
Intermediate Host ◽  
Leaf Extracts ◽  
Urinary Schistosomiasis ◽  
Bulinus Truncatus

Nicotiana tobaccum L (Solanacea) extracts are used as a mollusciede to the snail Bulinus truncatus the intermediate host of urinary Schistosomiasis. LC50 of the extracts to the snail with 24 hour was 3.27 ml/l? 48 hour was 3.33 ml/l? 72 hour was 2.67 ml/l and 96 hour was 2.28ml/l. This study showed the ability to use the leaf extracts in the control of this type of snail.

Detection and characterisation of hepatitis E virus in naturally infected swine in Croatia

2013 ◽  
Vol 61 (4) ◽  
pp. 517-528 ◽  
Author(s):  
Zoran Lipej ◽  
Dinko Novosel ◽  
Lea Vojta ◽  
Besi Roić ◽  
Miljenko Šimpraga ◽  
...  
Keyword(s):  
Hepatitis E Virus ◽  
Age Groups ◽  
Hepatitis E ◽  
Health Concern ◽  
Rt Pcr ◽  
Animal Reservoir ◽  
Naturally Occurring ◽  
High Prevalence ◽  
Swine Herds ◽  
Bile Samples

Hepatitis E is a viral zoonotic disease infecting swine worldwide. Since pigs represent a likely animal reservoir for the hepatitis E virus, the epidemiology of naturally occurring hepatitis E was investigated in Croatian swine herds. Nearly all tested animals were seropositive for antibodies against the hepatitis E virus (55/60, 91.7%). Active infection was detected in all age groups by RT-PCR of viral RNA in serum (8/60, 13.3%) and bile samples (3/37, 8.1%), which was further confirmed by histopathological findings of characteristic lesions in the livers of the infected animals. Three new strains of hepatitis E virus were isolated from Croatian pig herds. Phylogenetic analysis using median-joining networks clustered those Croatian strains with isolates from various parts of the world, indicating their likely origin in international trade. Similarity to human isolates implies a zoonotic potential of Croatian strains, which raises a public health concern, especially in the light of the high prevalence of hepatitis E in the herds studied.

scholarly journals The Effect of Trematode Parasites on the Growth of Littorina Neritoides (L.)

1941 ◽  
Vol 25 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Miriam Rothschild
Keyword(s):  
Intermediate Host ◽  
Large Size ◽  
Size Groups ◽  
Second Intermediate Host ◽  
Upward Slope ◽  
Accelerated Growth ◽  
The Difference ◽  
First Intermediate Host ◽  
Low Rate ◽  
Trematode Parasites

If the number of infections with (a) trematode parthenitae and cercariae using Littorina neritoides as first intermediate host only, and (b) encysted metacercariae using L. neritoides as second intermediate host only, are plotted against the size of the snails, two different curves result. The first shows a low rate of infection in the small size groups, but a steep upward slope rising to 91% in the large size groups. The second shows a curve increasing uniformly to 87% infection.Possible interpretations are discussed, and it is concluded that the difference is probably due to the fact that primary infections cause accelerated growth in the host.

Biological Parameters of Three Populations of Triatoma dimidiata s. s. (Hemiptera: Reduviidae) From Western Mexico

2021 ◽  
Author(s):  
Benjamin Nogueda-Torres ◽  
Oziel D Montañez-Valdez ◽  
J G Michel-Parra ◽  
Diana M Martínez-Grant ◽  
J Alejandro Martínez-Ibarra
Keyword(s):  
Pacific Coast ◽  
Median Number ◽  
Sensu Stricto ◽  
Human Populations ◽  
Western Mexico ◽  
Post Feeding ◽  
The Pacific ◽  
High Prevalence ◽  
Vector Borne ◽  
Cruzi Infection

Abstract Chagas disease is a very important vector-borne disease in México, and Triatoma dimidiata sensu stricto (Latreille) is one of the most important vectors of Trypanosoma cruzi Chagas, mainly in southern and central states. In the Pacific Coast states with the highest prevalence of human T. cruzi infection, T. dimidiata s. s. is considered as a secondary vector. However, the vectorial capacity of those populations has not been studied. Therefore, the vector characteristics of three populations of T. dimidiata s. s. in western México were evaluated in this study. The populations were maintained in the laboratory at 27 ± 1°C and 75% ± 5% RH with a 12:12 h (light:dark) regime, fed on rabbits in a fortnight basis. The development times were short (172–238 d), and the number of bloodmeals to molt was low (11). Mortality was moderate (36–45%), the onset of feeding was relatively rapid (0.5–1.7 min), and feedings were extended (>15 min). More than 40% of individuals in most instars defecated in one of three categories: <1 min when feeding (5–37.9%), immediately after feeding (9–28.6%), or in <1 min post feeding (7–25.8%). The median number of laid eggs was high (over 2.5) in the three populations, as were the egg eclosion rates (>86%). Thus, the T. dimidiata s. s. in the three populations are potentially efficient vectors of T. cruzi and could contribute to the high prevalence of infection in human populations in western México.

Microcystin Exposure Pathways and Human Health

2020 ◽  
pp. 1-5
Author(s):  
Rajesh Melaram ◽  
Keyword(s):  
Public Health ◽  
Policy Development ◽  
Mitigation Strategies ◽  
World Health ◽  
Health Concern ◽  
Human Populations ◽  
Algal Toxins ◽  
Potential Health ◽  
Exposure Pathways ◽  
Green Algal

Microcystins (MCs) are blue-green algal toxins produced by freshwater cyanobacteria. Their environmentally relevant concentrations throughout global surface waters have tampered with human populations’ drinking and recreational supplies. MCs have gained immense public health attention due to their potential health effects. Microcystin-LR (MC-LR) is the most toxic variant of the MCs. Investigations on MC-LR toxicity and detection in water signify a growing potential environmental health concern worldwide. The World Health Organization established a provisional drinking water guidance value of 1 μg/L and a provisional recreational exposure guidance value of 10 μg/L for MC-LR. This review surveys human MC exposure pathways and integrates epidemiological studies to support MCs’ critical exposure pathways. A discussion on monitoring and mitigation strategies provides a guide for policy development in adopting MCs’ regulatory levels to protect public health.

scholarly journals Phylogeography of Bulinus truncatus (Audouin, 1827) (Gastropoda: Planorbidae) in Selected African Countries

2018 ◽  
Vol 3 (4) ◽  
pp. 127 ◽  
Author(s):  
Eniola Abe ◽  
Yun-Hai Guo ◽  
Haimo Shen ◽  
Masceline Mutsaka-Makuvaza ◽  
Mohamed Habib ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Haplotype Diversity ◽  
Snail Host ◽  
Snail Species ◽  
African Countries ◽  
Urinary Schistosomiasis ◽  
Bulinus Truncatus ◽  
High Haplotype Diversity ◽  
Gene Coi ◽  
Mitochondrial Cytochrome Oxidase

The transmission of some schistosome parasites is dependent on the planorbid snail hosts. Bulinus truncatus is important in urinary schistosomiasis epidemiology in Africa. Hence, there is a need to define the snails’ phylogeography. This study assessed the population genetic structure of B. truncatus from Giza and Sharkia (Egypt), Barakat (Sudan) and Madziwa, Shamva District (Zimbabwe) using mitochondrial cytochrome oxidase subunit 1 gene (COI) and internal transcribed spacer 1 (ITS 1) markers. COI was sequenced from 94 B. truncatus samples including 38 (Egypt), 36 (Sudan) and 20 (Zimbabwe). However, only 51 ITS 1 sequences were identified from Egypt (28) and Sudan (23) (because of failure in either amplification or sequencing). The unique COI haplotypes of B. truncatus sequences observed were 6, 11, and 6 for Egypt, Sudan, and Zimbabwe, respectively. Also, 3 and 2 unique ITS 1 haplotypes were observed in sequences from Egypt and Sudan respectively. Mitochondrial DNA sequences from Sudan and Zimbabwe indicated high haplotype diversity with 0.768 and 0.784, respectively, while relatively low haplotype diversity was also observed for sequences from Egypt (0.334). The location of populations from Egypt and Sudan on the B. truncatus clade agrees with the location of both countries geographically. The clustering of the Zimbabwe sequences on different locations on the clade can be attributed to individuals with different genotypes within the population. No significant variation was observed within B. truncatus populations from Egypt and Sudan as indicated by the ITS 1 tree. This study investigated the genetic diversity of B. truncatus from Giza and Sharkia (Egypt), Barakat area (Sudan), and Madziwa (Zimbabwe), which is necessary for snail host surveillance in the study areas and also provided genomic data of this important snail species from the sampled countries.

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