The neglected tropical diseases (NTDs) are the most common conditions affecting the poorest 500 million people living in sub-Saharan Africa (SSA), and together produce a burden of disease that may be equivalent to up to one-half of SSA's malaria disease burden and more than double that caused by tuberculosis. Approximately 85% of the NTD disease burden results from helminth infections. Hookworm infection occurs in almost half of SSA's poorest people, including 40-50 million school-aged children and 7 million pregnant women in whom it is a leading cause of anemia. Schistosomiasis is the second most prevalent NTD after hookworm (192 million cases), accounting for 93% of the world's number of cases and possibly associated with increased horizontal transmission of HIV/AIDS. Lymphatic filariasis (46-51 million cases) and onchocerciasis (37 million cases) are also widespread in SSA, each disease representing a significant cause of disability and reduction in the region's agricultural productivity. There is a dearth of information on Africa's non-helminth NTDs. The protozoan infections, human African trypanosomiasis and visceral leishmaniasis, affect almost 100,000 people, primarily in areas of conflict in SSA where they cause high mortality, and where trachoma is the most prevalent bacterial NTD (30 million cases). However, there are little or no data on some very important protozoan infections, e.g., amebiasis and toxoplasmosis; bacterial infections, e.g., typhoid fever and non-typhoidal salmonellosis, the tick-borne bacterial zoonoses, and non-tuberculosis mycobaterial infections; and arboviral infections. Thus, the overall burden of Africa's NTDs may be severely underestimated. A full assessment is an important step for disease control priorities, particularly in Nigeria and the Democratic Republic of Congo, where the greatest number of NTDs may occur.

/pdf/neglected-tropical-diseases-in-sub-saharan-africa-review-of-4lmwsw4m2v.pdf

Neglected tropical diseases in sub-saharan Africa: review of their prevalence, distribution, and disease burden.

SUMMARY

The prevalence and intensity of infections caused by protozoa, nematodes, trematodes, cestodes, and arthropods is higher in males than females. The primary thesis of this review is that immunological differences exist between the sexes that may underlie increased parasitism in males compared to females. Several field and laboratory studies link sex differences in immune function with circulating steroid hormones; thus, the roles of sex steroids, including testosterone, oestradiol, and progesterone, as well as glucocorticoids will be discussed. Not only can host hormones affect responses to infection, but parasites can both produce and alter hormone concentrations in their hosts. The extent to which changes in endocrine–immune interactions following infection are mediated by the host or the parasite will be considered. Although males are more susceptible than females to many parasites, there are parasites for which males are more resistant than females and endocrine–immune interactions may underlie this sex reversal. Finally, although immunological differences exist between the sexes, genetic and behavioural differences may explain some variability in response to infection and will be explored as alternative hypotheses for how differences between the sexes contribute to dimorphic responses to parasites.

http://www.higiene.edu.uy/ubp/ubp_files/papers/2-7%20Hormonal.pdf

Hormonal and immunological mechanisms mediating sex differences in parasite infection

The scientific study of human hookworm infection began at the dawn of the twentieth century. In recent years, there have been dramatic improvements in our understanding of many aspects of this globally widespread parasite. This chapter reviews recent advances in our understanding in the biology, immunology, epidemiology, public health significance and control of hookworm, and to look forward to the study of this important parasite in the 21st century. Advances in molecular biology has lead to the identification of a variety of new molecules from hookworms, which have importance either in the molecular pathogenesis of hookworm infection or in the host-parasite relationship; some are also promising vaccine targets. At present, relatively little is known about the immune responses to hookworm infection, although it has recently been speculated that hookworm and other helminths may modulate specific immune responses to other pathogens and vaccines. Our epidemiological understanding of hookworm has improved through the development of mathematical models of transmission dynamics, which coupled with decades of field research across multiple epidemiological settings, have shown that certain population characteristics can now be recognised as common to the epidemiology, population biology and control of hookworm and other helminth species. Recent recognition of the subtle, but significant, impact of hookworm on health and education, together with the simplicity, safety, low cost and efficacy of chemotherapy has spurred international efforts to control the morbidity due to infection. Large-scale treatment programmes are currently underway, ideally supported by health education and integrated with the provision of improved water and sanitation. There are also on-going efforts to develop novel anthelmintic drugs and anti-hookworm vaccines.

/pdf/human-hookworm-infection-in-the-21st-century-3dwtgqw9po.pdf

Human Hookworm Infection in the 21st Century

The biochemical basis of anthelmintic action and resistance.

Objective  To evaluate efficacies of anthelmintic drugs against soil transmitted helminths in terms of cure rates and egg reduction rates. Design  Systematic review and network meta-analysis. Data Sources  PubMed, ISI Web of Science, Embase, ScienceDirect, the Cochrane Central Register of Clinical Trials, and the World Health Organization library database from 1960 until 31 December 2016. Study selection  Randomised controlled trials evaluating the efficacy of a single dose regimen of albendazole, mebendazole, levamisole, and pyrantel pamoate against Ascaris lumbricoides , hookworm ( Necator americanus and Ancylostoma duodenale ) and Trichuris trichiura. The primary outcomes included cure rates analysed by network meta-analysis with mixed logistic regression models and egg reduction rates with mixed linear models. Results  55 and 46 randomised controlled trials were included in the analysis of cure rates and egg reduction rates, respectively. All drugs were highly efficacious against A lumbricoides . Albendazole showed the highest efficacy against hookworm infections with a cure rate of 79.5% (95% confidence interval 71.5% to 85.6%) and an egg reduction rate of 89.6% (81.9% to 97.3%). All drugs had low efficacy against T trichiura , with mebendazole showing the highest cure rate of 42.1% (25.9% to 60.2%) and egg reduction rate of 66.0% (54.6% to 77.3%). Estimates for the years 1995 and 2015 showed significant reductions in efficacy of albendazole against T trichiura : by 2015 the egg reduction rates fell from 72.6% (53.7% to 91.5%) to 43.4% (23.5% to 63.3%; P=0.049) and the cure rates fell from 38.6% (26.2% to 52.7%) to 16.4 (7.7% to 31.3%; P=0.027). Conclusions  All four currently recommended drugs show limitations in their efficacy profile. While only albendazole showed good efficacy against hookworm infection, all drugs had low efficacy against T trichiura . The decrease in efficacy of albendazole against T trichiura over the past two decades is of concern. The findings indicate the need for strengthening efforts to develop new drug treatments, with a particular focus on drugs against T trichiura .

https://www.bmj.com/content/bmj/358/bmj.j4307.full.pdf

Efficacy of recommended drugs against soil transmitted helminths: systematic review and network meta-analysis

A randomized, placebo-controlled trial of the efficacy of pyrantel (single dose 12.5 mg/kg bodyweight), mebendazole (single 500 mg dose) and albendazole (single 400 mg dose) in the treatment of hookworm infections (Necator americanus) was carried out in January 1998 in the Southern Region of Mali, West Africa, during the period of Ramadan (Islamic fast). Statistical analysis of the pre-intervention faecal egg counts showed that there was a significant pre-treatment chance bias, despite randomization of subjects into treatment groups, arising from the main effect of sex (heavier infections among males) and a sex x treatment interaction (the sex bias was not evident in the pyrantel-treatment group). The participants were re-examined 10 days after treatment, and after controlling for the drift in faecal egg counts in the placebo-treated subset, age, sex, fasting and intensity of infection, albendazole was clearly the most effective drug showing consistently efficacies in the range 92.1 to 99.7%, depending on the method of evaluation and the particular subset of the treatment group. Neither mebendazole nor pyrantel was as effective, with efficacies ranging from 60.9 to 89.8% and 4.8 to 89.7%, respectively. Fasting made no difference to drug efficacy. On the basis of our results the single 400 mg dose of albendazole is the treatment of choice for hookworm infections in this region of Mali. We emphasize the need for standardization of the methods used for trial designs, for calculation of summary data relating to drug efficacies and the accompanying statistical tests.

Comparison of the efficacy of mebendazole, albendazole and pyrantel in treatment of human hookworm infections in the Southern Region of Mali, West Africa

Two surveys of hookworm (Necator americanus) infections, conducted three years apart (December 1994 and January 1998) in a village in the Sikasso region of Mali, revealed that overall prevalence of infection was 68.7% and 53%, respectively. In both years there was a highly significant difference between the sexes in the prevalence and abundance of infection, with male subjects carrying heavier infections than females. Both prevalence and abundance of infection increased with age, although in 1998 there was a strong interaction between sex and age, arising from the declining egg counts among 16-20-year-old females and the continuing increase among males, reinforced by the subsequent reduction among the older males (> or = 61 years) and concomitant increase among females. After controlling for the effects of age, sex and their interaction, a highly significant positive relationship was detected between faecal egg counts of individuals who were examined in both 1994 and 1998 (n = 134), indicating predisposition to infection. This relationship remained significant in each of 4 age classes spanning 7-79 years. The members of some family compounds were shown to carry heavier infections than expected whilst others were less infected, suggesting compound-related clustering of hookworm infections. The use of footwear increased with age but there was no significant relationship between the extent of use of footwear and the abundance of hookworm infection. Eyesight deteriorated with age and impaired vision was particularly prominent among the older sectors of the community, a legacy from the time when onchocerciasis was widely prevalent in the region. Although men with partially damaged eyes carried lower infections than expected for their age, no overall significant relationship was found between quality of vision and hookworm infections. These results are discussed in relation to hookworm epidemiology in general and in Mali in particular.

The epidemiology of human hookworm infections in the southern region of Mali.

Polyparasitism with Schistosoma haematobium and soil-transmitted helmith infections among school children in Loum, Cameroon (vol 8, pg 975, 2003)

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Fs Gilbert

Author Tools

Chat about Author

Papers

Comparison of the efficacy of mebendazole, albendazole and pyrantel in treatment of human hookworm infections in the Southern Region of Mali, West Africa

The epidemiology of human hookworm infections in the southern region of Mali.

Polyparasitism with Schistosoma haematobium and soil-transmitted helmith infections among school children in Loum, Cameroon (vol 8, pg 975, 2003)