- Competing for blood: the ecology of parasite resource competition in human malaria-helminth co-infections. [Letter]
- ELEcol Lett 2018 Feb 08
- Ecological theory suggests that co-infecting parasite species can interact within hosts directly, via host immunity and/or via resource competition. In mice, competition for red blood cells (RBCs) be...
Ecological theory suggests that co-infecting parasite species can interact within hosts directly, via host immunity and/or via resource competition. In mice, competition for red blood cells (RBCs) between malaria and bloodsucking helminths can regulate malaria population dynamics, but the importance of RBC competition in human hosts was unknown. We analysed infection density (i.e. the concentration of parasites in infected hosts), from a 2-year deworming study of over 4000 human subjects. After accounting for resource-use differences among parasites, we find evidence of resource competition, priority effects and a competitive hierarchy within co-infected individuals. For example reducing competition via deworming increased Plasmodium vivax densities 2.8-fold, and this effect is limited to bloodsucking hookworms. Our ecological, resource-based perspective sheds new light into decades of conflicting outcomes of malaria-helminth co-infection studies with significant health and transmission consequences. Beyond blood, investigating within-human resource competition may bring new insights for improving human health.
- The role of family size, employment and education of parents in the prevalence of intestinal parasitic infections in school children in Accra. [Journal Article]
- PlosPLoS One 2018; 13(2):e0192303
- CONCLUSIONS: Intestinal parasites were prevalent in children from overcrowded families and with no knowledge of IPIs. Educative programmes on IPIs, improving hygiene, and application of supportive programmes to elevate socioeconomic conditions may help reduce the burden of intestinal parasite carriage in children.
- The optimal timing of post-treatment sampling for the assessment of anthelminthic drug efficacy against Ascaris infections in humans. [Journal Article]
- IJInt J Parasitol Drugs Drug Resist 2018 Jan 13; 8(1):67-69
- The egg reduction rate (ERR) is the current standard mean to assess the efficacy of drugs against human soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura and hookworm). Alth...
The egg reduction rate (ERR) is the current standard mean to assess the efficacy of drugs against human soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura and hookworm). Although the timing of post-treatment sampling is pivotal for a readily interpretation of drug efficacy, there is lack empirical data that allows recommending the optimal time point for a follow-up egg counting. In the present study, we re-analyzed both the kinetics of worm expulsion and egg output for Ascaris lumbricoides following a single oral dose of albendazole in a series of studies previously conducted in Kenyan communities. The results indicate that it takes up to 10 days post-treatment before the expulsion of both adult male and female Ascaris worms is completed, approximately 20% of the worms being expelled between day 7 and 10 post-treatment. The sequential analysis of the egg out put, indicated a poor ERR (89.4%) at day 7 post-treatment, but a 100% ERR at day 14 and 21 post-treatment. Based on our findings we recommend to wait at least 14 days after an albendazole treatment before conducting the follow-up egg count. Any sampling before this time point may result in biased ERR estimates, due the release of residual eggs from moribund or degenerating worms.
- The Risk of Chronic Gastrointestinal Disorders Following Acute Infection with Intestinal Parasites. [Journal Article]
- FMFront Microbiol 2018; 9:17
- CONCLUSIONS: We found that parasite-associated enteric infection increases the risk of development of post-infectious chronic gastrointestinal disorders in a military population. These results require confirmation in similar populations and in the developing world where infection with these parasites is endemic. Further understanding of disease burden and causal mechanisms should direct primary prevention and potential disease interception strategies.
- Ascaris in the urinary tract: A case report and review of the literature. [Journal Article]
- UCUrol Case Rep 2018; 17:82-84
- Current epidemiological evidence for predisposition to high or low intensity human helminth infection: a systematic review. [Review]
- PVParasit Vectors 2018 Jan 31; 11(1):65
- CONCLUSIONS: This review has found consistent evidence of predisposition to heavy (and light) infection for certain human helminth species. However, further research is needed to identify reasons for the reported differences between demographic groups. Molecular epidemiological methods associated with whole genome sequencing to determine 'who infects whom' may shed more light on the factors generating predisposition.
- Helminth lifespan interacts with non-compliance in reducing the effectiveness of anthelmintic treatment. [Journal Article]
- PVParasit Vectors 2018 Jan 31; 11(1):66
- CONCLUSIONS: Our analysis suggests that achieving reductions in the level of systematic non-compliance may be of particular benefit in mass drug administration programmes treating the longer-lived helminth parasites, and highlights the need for improved data collection in understanding the impact of compliance.
- Prevalence and intensity of Ascaris lumbricoides infections in relation to undernutrition among children in a tea plantation community, Sri Lanka: a cross-sectional study. [Journal Article]
- BPedBMC Pediatr 2018 01 25; 18(1):13
- CONCLUSIONS: Ascaris infections and undernutrition are still highly prevalent and a major public health problem in the plantation sector in Sri Lanka. Health and nutrition intervention programs should be implemented to increase the nutritional status of children.
- Expanding molecular diagnostics of helminthiasis: Piloting use of the GPLN platform for surveillance of soil transmitted helminthiasis and schistosomiasis in Ghana. [Journal Article]
- PNPLoS Negl Trop Dis 2018; 12(1):e0006129
- The efforts to control and eradicate polio as a global health burden have been successful to the point where currently only three countries now report endemic polio, and the number of cases of polio ...
The efforts to control and eradicate polio as a global health burden have been successful to the point where currently only three countries now report endemic polio, and the number of cases of polio continues to decrease. The success of the polio programme has been dependant on a well-developed network of laboratories termed the global polio laboratory network (GPLN). Here we explore collaborative opportunities with the GPLN to target two of the 18 diseases listed as a neglected tropical diseases (NTD) namely soil transmitted helminthiasis (STH) and Schistosomiasis (SCH). These were chosen based on prevalence and the use of faecal materials to identify both polio, STH and SCH. Our study screened 448 faecal samples from the Ghana GPLN using three triplex TaqMan assays to identify Ascaris lumbricoides, Necator americanus, Ancylostoma spp, Trichuris trchiura, Strongyloides stercoralis and Schistosoma spp. Our results found a combined helminth prevalence of 22%. The most common helminth infection was A. lumbricoides with a prevalence of 15% followed by N. americanus (5%), Ancylostoma spp. (2.5%), Schistosoma spp. (1.6%) and S. stercoralis (1%). These results show that it is possible to identify alternative pathogens to polio in the samples collected by the GPLN platform and to introduce new diagnostic assays to their laboratories. The diagnostic methods employed were also able to identify S. stercoralis positive samples, which are difficult to identify using parasitological methods such as Kato-Katz. This study raises the possibility of collaboration with the GPLN for the surveillance of a wider range of diseases which would both benefit the efforts to control the NTDs and also increase the scope of the GPLN as a diagnostic platform.
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- Intestinal parasites: associations with intestinal and systemic inflammation. [Journal Article]
- PIParasite Immunol 2018 Jan 24
- CONCLUSIONS: Intestinal parasitic infection was not associated with systemic inflammation, but was associated with intestinal inflammation. Having multiple-infections were associated with higher leptin concentrations. This article is protected by copyright. All rights reserved.