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The American Journal of Tropical... May 2018
Topics: Albendazole; Ancylostomatoidea; Animals; Double-Blind Method; Farmers; Female; Hookworm Infections; Humans; Power, Psychological
PubMed: 29611502
DOI: 10.4269/ajtmh.17-0934 -
PLoS Neglected Tropical Diseases Jun 2022Hookworm disease is endemic in China and is widespread globally. The disease burden to humans is great.
BACKGROUND
Hookworm disease is endemic in China and is widespread globally. The disease burden to humans is great.
METHODS
The study described the national surveillance of hookworm implemented in 31 provinces/autonomous regions/municipalities (P/A/Ms) of China in 2019. Each P/A/M determined the number and location of surveillance spots (counties). A unified sampling method was employed, and at least 1000 subjects were investigated in each surveillance spot. The modified Kato-Katz thick smear method was employed for stool examination. Fifty samples positive with hookworm eggs were cultured in each surveillance spot to discriminate species between A. duodenale and N. americanus. Twenty-five soil samples were collected from each surveillance spot and examined for hookworm larva. The 2019 surveillance results were analyzed and compared with that of 2016-2018.
RESULTS
A total of 424766 subjects were investigated in 31 P/A/Ms of China in 2019, and the overall hookworm infection rate was 0.85% (3580/424766). The weighted infection and standard infection rates were 0.66% (4288357/648063870) and 0.67% (4343844/648063870), respectively. Sichuan province had the highest standard infection rate (4.75%) in 2019, followed by Chongqing (2.54%) and Hainan (2.44%). The standard infection rates of other P/A/Ms were all below 1%, with no hookworm detected in 15 P/A/Ms. The standard hookworm infection rate in the males and the females were 0.61% (2021216/330728900) and 0.71% (2267141/317334970), respectively, with a significant difference between different genders ([Formula: see text] = 17.23, P<0.0001). The highest standard hookworm infection rate (1.97%) was among age ≥ 60 years, followed by 45~59 years (0.77%), 15~44 years (0.37%), and 7~14 years (0.20%). The lowest standard infection rate was among the 0~6 years age group (0.12%). A significant difference was observed among different age groups ([Formula: see text] = 2 305.17, P<0.0001). The constitute ratio for N. americanus, A. duodenale, and coinfection was 78.70% (1341/1704), 2.03% (346/1704), and 1.00% (17/1704), respectively. The detection rate of hookworm larva from soil was 3.45% (71/2056).
CONCLUSION
The national surveillance showed that the hookworm infection rate has been decreasing annually from 2016 to 2019, and it is now below 1%. China has made significant progress in controlling hookworm. The national surveillance system is an important way to understand the endemic status and provide important information in this process and thus needs to be continually optimized.
Topics: Ancylostomatoidea; Animals; China; Feces; Female; Hookworm Infections; Humans; Male; Middle Aged; Prevalence; Soil
PubMed: 35679319
DOI: 10.1371/journal.pntd.0010405 -
Zhong Nan Da Xue Xue Bao. Yi Xue Ban =... Jun 2022With the improvement of sanitation, the infection rate of hookworm is greatly reduced and the severe infected case is rarely reported. Combined morphological and...
With the improvement of sanitation, the infection rate of hookworm is greatly reduced and the severe infected case is rarely reported. Combined morphological and molecular biological examinations, a severe hookworm infection patient was diagnosed in Department of Laboratorial Examination, Quanzhou First Affiliated Hospital of Fujian Medical University. The morphological methods such as direct fecal smear microscopy, saturated brine flotation and hookworm larvae culture methods were used to identify the eggs and larvae from stool samples of the patient. There were a large number of hookworm eggs in patient's stool samples, and the average count was 60 840 per gram by modified Kato method, which belonged to severe hookworm infection. Meanwhile, to distinguish the hookworm species, the semi-nested RT-PCR assay was employed to detect hookworm internal transcribed spacer series from eggs in patient's stool samples, and the result showed that the hookworm species was confirmed to be .
Topics: Ancylostomatoidea; Animals; Feces; Hookworm Infections; Humans; Necator americanus; Polymerase Chain Reaction
PubMed: 35837783
DOI: 10.11817/j.issn.1672-7347.2022.210593 -
The Lancet. Microbe Jan 2022The global distribution and morbidity effects for each specific hookworm species is unknown, which prevents implementation of the optimum intervention for local hookworm... (Review)
Review
The global distribution and morbidity effects for each specific hookworm species is unknown, which prevents implementation of the optimum intervention for local hookworm control. We did two systematic reviews of studies on the proportion of hookworm isolates of each species and genus by region of the world and associations between hookworm species-specific infections and morbidity outcomes, particularly severe anaemia. Necator americanus and Ancylostoma spp were present in all regions of the world, although at different ratios. No clear evidence was found for the differential morbidity effects of different hookworm species. Diagnostic methods that differentiate between hookworm species, including molecular methods, need to be developed for widespread use in control programmes to elucidate key features of hookworm epidemiology and control.
Topics: Ancylostoma; Ancylostomatoidea; Animals; Feces; Hookworm Infections; Humans; Morbidity
PubMed: 35544117
DOI: 10.1016/S2666-5247(21)00181-6 -
Human Vaccines Nov 2011The human hookworms Necator americanus and Ancylostoma duodenale remain among the most common infections of humans in areas of rural poverty in the developing regions of... (Review)
Review
The human hookworms Necator americanus and Ancylostoma duodenale remain among the most common infections of humans in areas of rural poverty in the developing regions of the world, with an estimated 1 billion people infected with one or more of these parasites. Herein, we review the nearly 100 years of research, development, animal testing, and fieldwork that have led to our current progress in recombinant hookworm vaccines. We begin with the identification of hookworm at the start of the 20th century in Southern US, then discuss the progress in developed countries to eliminate human hookworm infection, and then the industrial development and field use in the 1970s a canine hookworm vaccine(Ancylostoma caninum), and finally our progress to date in the development and clinical testing of an array of recombinant antigens to prevent human hookworm disease from N. americanus infection. Special attention is given to the challenges faced in the development of a vaccine against a blood-feeding nematode, including the epidemiology of infection (high prevalence of infection), pathogenesis (chronic infection that increases with the age of the host), and a robust immune response that fails to confer the protection in the host and a concomitant absence of correlates of protection by a successful vaccine could be developed and tested. Finally, we provide the optimal and acceptable profiles of a human hookworm vaccine, including the proposed indication, target population, and route of administration, as developed by the Human Hookworm Vaccine Initiative, the only group currently working on vaccines targeting this parasite.
Topics: Ancylostoma; Ancylostomatoidea; Ancylostomiasis; Animals; Antigens, Helminth; Dog Diseases; Dogs; Humans; Necator americanus; Necatoriasis; Vaccines, Synthetic
PubMed: 22064562
DOI: 10.4161/hv.7.11.18443 -
Emerging Infectious Diseases Sep 2022Ancylostoma ceylanicum hookworms are zoonotic parasites that can infect humans. To detect autochthonous transmission, we analyzed human fecal samples collected in 2000....
Ancylostoma ceylanicum hookworms are zoonotic parasites that can infect humans. To detect autochthonous transmission, we analyzed human fecal samples collected in 2000. Multiparallel quantitative PCR detected infection in persons who had never traveled outside Ecuador. These data indicate human transmission of A. ceylanicum in the Americas, although endemicity remains unknown.
Topics: Ancylostoma; Ancylostomatoidea; Ancylostomiasis; Animals; Ecuador; Hookworm Infections; Humans; Zoonoses
PubMed: 35997627
DOI: 10.3201/eid2809.220248 -
Parasites & Vectors Jan 2016Soil-transmitted helminth (STH) infections of humans fall within the World Health Organization's (WHO) grouping termed the neglected tropical diseases (NTDs). It is... (Review)
Review
Soil-transmitted helminth (STH) infections of humans fall within the World Health Organization's (WHO) grouping termed the neglected tropical diseases (NTDs). It is estimated that they affect approximately 1.4 billion people worldwide. A significant proportion of these infections are in the population of Southeast Asia. This review analyses published data on STH prevalence and intensity in Southeast Asia over the time period of 1900 to the present to describe age related patterns in these epidemiological measures. This is with a focus on the four major parasite species affecting humans; namely Ascaris lumbricoides, Trichuris trichiura and the hookworms; Necator americanus and Ancylostoma duodenale. Data were also collected on the diagnostic methods used in the published surveys and how the studies were designed to facilitate comparative analyses of recorded patterns and changes therein over time. PubMed, Google Scholar, EMBASE, ISI Web of Science, Cochrane Database of Systematic Reviews and the Global Atlas of Helminth Infections search engines were used to identify studies on STH in Southeast Asia with the search based on the major key words, and variants on, "soil-transmitted helminth" "Ascaris" "Trichuris" "hookworm" and the country name. A total of 280 studies satisfied the inclusion criteria from 11 Southeast Asian countries; Brunei, Cambodia, Indonesia, Lao People's Democratic Republic (Lao PDR), Malaysia, Myanmar, Philippines, Singapore, Thailand, Timor-Leste and Vietnam. It was concluded that the epidemiological patterns of STH infection by age and species mix in Southeast Asia are similar to those reported in other parts of the world. In the published studies there were a large number of different diagnostic methods used with differing sensitivities and specificities, which makes comparison of the results both within and between countries difficult. There is a clear requirement to standardise the methods of both STH diagnosis in faecal material and how the intensity of infection is recorded and reported in future STH research and in monitoring and evaluation (M&E) of the impact of continuing and expanding mass drug administration (MDA) programmes.
Topics: Ancylostoma; Ancylostomatoidea; Animals; Ascariasis; Ascaris lumbricoides; Asia, Southeastern; Feces; Helminthiasis; Helminths; Hookworm Infections; Humans; Prevalence; Research; Soil; Surveys and Questionnaires; Trichuriasis; Trichuris
PubMed: 26813007
DOI: 10.1186/s13071-016-1310-2 -
Expert Review of Vaccines Mar 2014The Sabin Vaccine Institute Product Development Partnership is developing a Pan-anthelmintic vaccine that simultaneously targets the major soil-transmitted nematode... (Review)
Review
The Sabin Vaccine Institute Product Development Partnership is developing a Pan-anthelmintic vaccine that simultaneously targets the major soil-transmitted nematode infections, in other words, ascariasis, trichuriasis and hookworm infection. The approach builds off the current bivalent Human Hookworm Vaccine now in clinical development and would ultimately add both a larval Ascaris lumbricoides antigen and an adult-stage Trichuris trichiura antigen from the parasite stichosome. Each selected antigen would partially reproduce the protective immunity afforded by UV-attenuated Ascaris eggs and Trichuris stichosome extracts, respectively. Final antigen selection will apply a ranking system that includes the evaluation of expression yields and solubility, feasibility of process development and the absence of circulating antigen-specific IgE among populations living in helminth-endemic regions. Here we describe a five year roadmap for the antigen discovery, feasibility and antigen selection, which will ultimately lead to the scale-up expression, process development, manufacture, good laboratory practices toxicology and preclinical evaluation, ultimately leading to Phase 1 clinical testing.
Topics: Ancylostomatoidea; Animals; Anthelmintics; Antigens, Helminth; Ascariasis; Ascaris lumbricoides; Hookworm Infections; Humans; Protozoan Vaccines; Soil; Trichuriasis; Trichuris
PubMed: 24392641
DOI: 10.1586/14760584.2014.872035 -
Clinical Microbiology Reviews Oct 2001Hookworms infect perhaps one-fifth of the entire human population, yet little is known about their interaction with our immune system. The two major species are Necator... (Review)
Review
Hookworms infect perhaps one-fifth of the entire human population, yet little is known about their interaction with our immune system. The two major species are Necator americanus, which is adapted to tropical conditions, and Ancylostoma duodenale, which predominates in more temperate zones. While having many common features, they also differ in several key aspects of their biology. Host immune responses are triggered by larval invasion of the skin, larval migration through the circulation and lungs, and worm establishment in the intestine, where adult worms feed on blood and mucosa while injecting various molecules that facilitate feeding and modulate host protective responses. Despite repeated exposure, protective immunity does not seem to develop in humans, so that infections occur in all age groups (depending on exposure patterns) and tend to be prolonged. Responses to both larval and adult worms have a characteristic T-helper type 2 profile, with activated mast cells in the gut mucosa, elevated levels of circulating immunoglobulin E, and eosinophilia in the peripheral blood and local tissues, features also characteristic of type I hypersensitivity reactions. The longevity of adult hookworms is determined probably more by parasite genetics than by host immunity. However, many of the proteins released by the parasites seem to have immunomodulatory activity, presumably for self-protection. Advances in molecular biotechnology enable the identification and characterization of increasing numbers of these parasite molecules and should enhance our detailed understanding of the protective and pathogenetic mechanisms in hookworm infections.
Topics: Ancylostomatoidea; Animals; Antigens, Helminth; Hookworm Infections; Host-Parasite Interactions; Humans; Hypersensitivity; Larva; Protozoan Vaccines
PubMed: 11585781
DOI: 10.1128/CMR.14.4.689-703.2001 -
Parasites & Vectors Nov 2022The Geshiyaro project is a 5-year intervention to assess the impact of community- and school-based water, sanitation, and hygiene (WaSH) interventions on reducing...
BACKGROUND
The Geshiyaro project is a 5-year intervention to assess the impact of community- and school-based water, sanitation, and hygiene (WaSH) interventions on reducing infection with soil-transmitted helminths (STH) and schistosome parasites in combination with deworming in Wolayita zone, Ethiopia.
METHODS
A population-based, cross-sectional census and parasitological mapping activity was conducted between 2018 and 2019. Individuals in the census were identified using either a registered study ID card or biometric fingerprint to enable linkage of their household WaSH data with baseline STH and schistosome prevalence for risk analysis.
RESULTS
Prevalence of STH was 15.5% for any STH species, 9.47% for Ascaris lumbricoides, 1.78% for Trichuris trichiura, and 7.24% for hookworm. Intestinal schistosomiasis (Schistosoma mansoni) infection prevalence was 0.85% by Kato Katz, 21.6% by POC-CCA trace positive (Tr +), and 13.3% trace negative (Tr-). Microhaematuria was 2.77%, with 0.13% of people examined with S. haematobium eggs detected by urine filtration. At the household level, increased (> 30 min) time taken to collect drinking water, sharing a latrine, and lack of handwashing facilities were all associated with a greater risk of A. lumbricoides, hookworm, and S. mansoni infection. Not disposing of infant stool at the household and clothes washing/recreational freshwater contact were significantly associated with higher risk of schistosomiasis infection. Aggregating WaSH data at the community level showed odds of A. lumbricoides, hookworm, and T. trichiura infection were significantly lower as both community sanitation coverage and access to improved drinking water improved.
CONCLUSIONS
The principal finding of this study is that lack of access to WaSH, such as improved drinking water and shared toilet and hand-washing facilities, were linked to an increased risk of infection with STH and schistosome parasites. These associations are difficult to establish at an individual household level because of wide variability in access between houses but are detectable when coverage is aggregated at the community level. Maintenance of WaSH facilities as well as increased access within the whole community is important in influencing the community-wide prevalence of infection with STH and schistosome parasites.
Topics: Infant; Animals; Humans; Sanitation; Soil; Prevalence; Cross-Sectional Studies; Drinking Water; Ethiopia; Hygiene; Helminths; Hookworm Infections; Ancylostomatoidea; Schistosoma mansoni; Feces; Schistosomatidae; Helminthiasis
PubMed: 36333779
DOI: 10.1186/s13071-022-05465-7