Richard Stewart Bradbury

• BBMedSc, PhD, FFSc RCPA, FASM, FACTM
• Associate Professor of Public Health and Tropical Medicine at James Cook University

The island of New Guinea is known to harbour a unique human infecting species of Strongyloides: Strongyloides fuelleborni subsp. kellyi. Stool DNA extracts (n=164) from 19 PNG infants, collected over 13 months, were analysed using Strongyloides real-time PCRs and underwent metabarcoding of cox1, 18S rRNA HVR-I and HVR-IV loci. Eight infants were in...

In many areas of The Gambia, West Africa, population crowding in a degraded environment has forced close interactions of diurnal primate species with humans. We assessed intestinal parasitic infection prevalence and diversity in 4 diurnal non-human primate (NHP) species, Chlorocebus sabaeus, Erythrocebus patas, Papio papio and Piliocolobus badius a...

Nematodes, or roundworms, are among the most common infections of humans in tropical regions of the world. It is estimated that between an estimated 642 million and 1.5 billion people are infected with Soil transmitted helminths alone. Most Pathologists are aware of the epidemiology, clinical significance, diagnosis and treatment of the common nema...

The detection and differentiation of intestinal parasites has previously relied mainly or primarily on microscopy, culture, and, to some extent, targeted PCR methods. Here, we give examples of how next-generation sequencing methods have been useful for improving parasite diagnostics and opening up new avenues for the generation of DNA data pertaini...

Human strongyloidiasis is often underdiagnosed or misdiagnosed, which can relate to a lack of knowledge or recognition of the importance of particular developmental/larval stages of Strongyloides stercoralis in making an accurate diagnosis using parasitological methods (a morphological approach or morphological features/characters). Here, we report...

In recent years, soil-transmitted helminthiases, including strongyloidiasis have become a prominent public health concern in the southeastern United States of America (USA). While there is ongoing human soil-transmitted helminths (STH) surveillance in Mississippi and Alabama, very little attention has been paid to potentially zoonotic STH from dogs...

A fecal survey in Tamil Nadu, India, revealed 2 persons passed schistosome eggs, later identified as Schistosoma incognitum, a parasite of pigs, dogs, and rats. We investigated those cases and reviewed autochthonous schistosomiasis cases from India and Nepal. Whether the 2 new cases represent true infection or spurious passage is undetermined.

The potential cross-transmission of Strongyloides stercoralis between dogs and humans has become an increasing focus of strongyloidiasis research and control programs. However, the role of cats and wild felids in the maintenance and transmission cycles of human and canine strongyloidiasis has received sparse attention. Feline strongyloidiasis epide...

We describe a case of a 2-year-old child who expelled a single adult female Ascaris lumbricoides worm. The patient is from a rural county in Mississippi, USA, with no reported travel outside of the United States. The caregivers in the home practice good sanitation. Exposure to domestic pigs is the likely source of infection.

Malignancy is a common reason for anatomical pathologists to examine and report on a wide range of specimens with typifying, grading and staging of malignancies playing an important role in patient care. This report details the case of a 75-year-old gentleman who underwent a right upper lobectomy and lymph node sampling for suspected primary pulmon...

Recent reports of hookworm infection in Alabama, USA, has prompted surveillance in Mississippi, given the states' similar environmental conditions. We collected stool specimens from 277 children in Rankin County, Mississippi. Kato-Katz microscopic smear, agar plate culture, and quantitative PCR indicated no soil-transmitted helminths. Nevertheless,...

We conducted a cross-sectional study to determine the prevalence of soil-transmitted helminthiases (STH) in areas of rural Alabama, USA, that have sanitation deficits. We enrolled 777 children; 704 submitted stool specimens and 227 a dried blood spot sample. We microscopically examined stool specimens from all 704 children by using Mini-FLOTAC for...

Strongyloides stercoralis infection remains a major veterinary and public health challenge globally. This chronic and potentially lifelong disease has fatal outcomes in immunosuppressed people and dogs. Currently, the role of dogs in the transmission cycle of human strongyloidiasis remains enigmatic. While zoonotic transmission to humans from compa...

The Strongyloides genus of parasitic nematodes have a fascinating life cycle and biology, but are also important pathogens of people and a World Health Organization-defined neglected tropical disease. Here, a community of Strongyloides researchers have posed thirteen major questions about Strongyloides biology and infection that sets a Strongyloide...

Strongyloidiasis is a World Health Organization neglected tropical disease usually caused by Strongyloides stercoralis , a parasitic worm with a complex life cycle. Globally, 300–600 million people are infected through contact with fecally contaminated soil. An autoinfective component of the life cycle can lead to chronic infection that may be asym...

Human infections with the protozoan Lophomonas have been increasingly reported in the medical literature over the past three decades. Initial reports were based on microscopic identification of the purported pathogen in respiratory specimens. Later, a polymerase chain reaction (PCR) was developed to detect Lophomonas blattarum, following which ther...

Parasitic diseases rank among the most prevalent and severe diseases worldwide. The danger of depending on drugs as one of the primary tools for control is compounded by the relatively limited number of antiparasitic agents available. The complex biologic interactions between parasites and their hosts (and, at times, their vectors) significantly in...

Nematodes are unsegmented cylindrical worms with a body cavity containing an alimentary canal and genital system; the sexes are separate. They have longitudinal muscles, which allow them to move by flexing their bodies. Molecular diagnosis for intestinal nematodes is increasingly being introduced in diagnostic laboratories. There are a variety of m...

Nematodes are unsegmented cylindrical worms with a body cavity containing an alimentary canal and genital system; the sexes are separate. They have longitudinal muscles, which allow them to move by flexing their bodies. Molecular diagnosis for intestinal nematodes is increasingly being introduced in diagnostic laboratories. There are a variety of m...

Parasitic diseases rank among the most prevalent and severe diseases worldwide. The danger of depending on drugs as one of the primary tools for control is compounded by the relatively limited number of antiparasitic agents available. The complex biologic interactions between parasites and their hosts (and, at times, their vectors) significantly in...

The taxonomy of medically important parasites continues to evolve. This minireview provides an update of additions and updates in the field of human parasitology from June 2020 through June 2022. A list of previously reported nomenclatural changes that have not been broadly adapted by the medical community is also included.

Background Strongyloides stercoralis is considered to be historically endemic in Appalachia and the American South, but recent surveillance data, especially data evaluating strongyloidiasis associated with hospitalization, are lacking in most parts of the US. Methods We performed a population-based retrospective analysis on strongyloidiasis using...

Polymerase chain reaction (PCR) is increasingly used in the diagnosis of soil-transmitted helminth infections. Despite this, few studies have evaluated the impact of different fecal fixatives on the outcome of fecal helminth qPCR analysis, and none have evaluated the effect of commercial parasitology fixatives commonly used in diagnostic laboratori...

A previously described universal parasite diagnostic (nUPDx) based on PCR amplification of the 18S rDNA and deep-amplicon sequencing, can detect human blood parasites with a sensitivity comparable to real-time PCR. To date, the efficacy of this assay has only been assessed on human blood. This study assessed the utility of nUPDx for the detection o...

We report an imported case of myositis caused by a rare parasite, Haycocknema perplexum, in Australia in a 37-year-old man who had progressive facial, axial, and limb weakness, dysphagia, dysphonia, increased levels of creatine kinase and hepatic aminotransferases, and peripheral eosinophilia for 8 years. He was given extended, high-dose albendazol...

Advances in laboratory techniques have revolutionized parasitology diagnostics over the past several decades. Widespread implementation of rapid antigen detection tests has greatly expanded access to tests for global parasitic threats such as malaria, while next-generation amplification and sequencing methods allow for sensitive and specific detect...

Strongyloidiasis is the infection caused by soil-transmitted nematodes of Strongyloides species, infecting humans and some animals. Strongyloides stercoralis is the species with most clinical and epidemiological relevance in humans and dogs, due to its high prevalence and its capacity of inducing a life-threatening hyperinfection. Diagnosis of stro...

Hepatic capillariasis is a neglected, but serious, hepatic disease with a world�wide distribution caused by the nematode Calodium hepaticum

The serologic diagnosis of chronic Chagas disease, caused by infection with the parasite Trypanosoma cruzi, is challenging and lacks a gold-standard assay. To overcome the problem, CDC uses an algorithm that uses two tests on different platforms and applies a third test as a tiebreaker. The Ortho T. cruzi ELISA Test System from Ortho Diagnostics wa...

Background Long-term persistence of Ebola virus (EBOV) in immunologically-privileged sites has been implicated in recent outbreaks of Ebola Virus Disease (EVD) in Guinea and the Democratic Republic of Congo. This study was designed to understand how the acute course of EVD, convalescence, and host immune and genetic factors may play a role in prolo...

•Neglected tropical diseases (NTDs) represent a threat to the health, wellbeing and economic prosperity of billions of people worldwide, often causing serious disease or death. •Commonly considered diseases of low and middle-income nations, the presence of NTDs in high income countries such as Australia is often overlooked. •Seven of the 20 recogni...

Background Strongyloides stercoralis is considered to be historically endemic in Appalachia and the American South, but recent surveillance data, especially data evaluating strongyloidiasis associated with hospitalization, are lacking in most parts of the US. Methods We performed a population-based retrospective analysis on strongyloidiasis using...

Non-typhoidal Salmonella associated with multidrug resistance cause invasive disease in sub-Saharan Africa. Specific lineages of serovars Typhimurium and Enteritidis have been implicated. Here we characterized the genomic diversity of 100 clinical non-typhoidal Salmonella collected from 93 patients in 2001 from the eastern, and in 2006–2018 from th...

This study systematically evaluates common laboratory disinfectants and storage conditions for their effectiveness in inactivating the infective stages of soil-transmitted helminths (STH). Animal-infecting proxy species were chosen to represent three major groups of STH that infect humans: roundworms, whipworms, and hookworms.

Strongyloidiasis remains endemic throughout the Island of New Guinea. While many infections are caused by Strongyloides stercoralis, a second human-infecting Strongyloides species, Strongyloides fuelleborni kellyi, is also present. S. f. kellyi infections are most common in infants and young children, and those with high-intensity infections might...

Background: The specific roles that gut microbiota, known pathogens, and host energy-regulating hormones play in the pathogenesis of non-edematous severe acute malnutrition (marasmus SAM) and moderate acute malnutrition (MAM) during outpatient nutritional rehabilitation are yet to be explored. Methods: We applied an ensemble of sample-specific (...

Strongyloidiasis represents a major medical and veterinary helminthic disease. Human infection is caused by three species; Strongyloides stercoralis, Strongyloides fuelleborni fuelleborni and Strongyloides fuelleborni kellyi, with S. stercoralis accounting for the majority of cases. Strongyloides f. fuelleborni likely represents a zoonosis acquired...

The species discussed herein are all nematodes that invade tissues, either in their adult or larval stages. A common feature among many of these species is low host specificity, which facilitates zoonotic transmission. Associated disease varies widely by the tissue impacted, and some manifestations such as invasion of the central nervous system (CN...

Intestinal nematodes (roundworms) infect up to one-fourth of the world’s population, primarily affecting people living in warm, moist climates in communities where poverty and poor sanitation favor transmission. Most helminths do not multiply in the human host (Strongyloides stercoralis and Capillaria philippinensis being notable exceptions), and t...

Surveillance for soil-transmitted helminths, strongyloidiasis, cryptosporidiosis, and giardiasis was conducted in Mississippi, USA. PCR performed on 224 fecal samples for all soil-transmitted helminths and on 370 samples for only Necator americanus and Strongyloides stercoralis identified 1 S. stercoralis infection. Seroprevalences were 8.8% for To...

All errors found in this paper are due to six samples included in the paper incorrectly assigned as being from Queensland, Australia. The report of Strongyloides fuelleborni infections from Australia made in this paper was incorrect, as those samples in fact originated in Guinea-Bissau and Senegal. There is an error in Table 4. Specimen Human 333_A...

Background Despite the known circulation of West Nile virus (WNV) and Usutu virus (USUV) in Slovakia, no formal entomological surveillance programme has been established there thus far. Aim To conduct contemporaneous surveillance of WNV and USUV in different areas of Slovakia and to assess the geographical spread of these viruses through mosquito...

We would like to thank Drs. Mathirus Mungthin, Saovanee Leelayoova, and Suradej Siripattanapippong for their letter in response to our manuscript “Medical Parasitology Taxonomy Update, January 2018 to May 2020” published in Journal of Clinical Microbiology (2021) Vol. 59, Issue 2, 12 e01308-20 (1).…

The taxonomy of parasites of medical and public health importance is rapidly evolving. This mini-review provides an update of taxonomic revisions and additions in the field of medical parasitology from January 2018-May 2020. Several established human parasites have been reassigned in genera over the past two years, while a number of novel parasites...

Background Targeted amplicon deep sequencing (TADS) has enabled characterization of diverse bacterial communities, yet the application of TADS to communities of parasites has been relatively slow to advance. The greatest obstacle to this has been the genetic diversity of parasitic agents, which include helminths, protozoa, arthropods, and some acan...

Strongyloidiasis and HTLV-I (human T-lymphotropic virus-1) are important infections that are endemic in many countries around the world with an estimated 370 million infected with Strongyloides stercoralis alone, and 5–10 million with HTVL-I. Co-infections with these pathogens are associated with significant morbidity and can be fatal. HTLV-I infec...

Non-typhoidal Salmonella associated with multidrug resistance cause invasive disease in sub-Saharan African. Specific lineages of serovars S . Typhimurium and S . Enteritidis are implicated. We characterised the genomic diversity of 100 clinical Non-typhoidal Salmonella collected from 93 patients in 2001 from the eastern and 2006 to 2018 in the wes...

Background: Recently reports of foci of hookworm and strongyloidiasis in rural Alabama has highlighted the possibility of continued soil transmitted helminth (STH) transmission in the American South. However, very little active parasitic disease surveillance has been undertaken in this region since the second decade of the last century. Methods:...

Evaluation of an ensemble-based distance statistic for clustering MLST datasets using epidemiologically defined clusters of cyclosporiasis - Fernanda S. Nascimento, Joel Barratt, Katelyn Houghton, Mateusz Plucinski, Julia Kelley, Shannon Casillas, Carolyne (Cody) Bennett, Cathy Snider, Rashmi Tuladhar, Jenny Zhang, Brooke Clemons, Susan Madison-Ant...

In the United States and Europe, human onchocerciasis is a rare disease caused by zoonotic or anthropophilic parasites in the genus Onchocerca. The zoonotic species identified in focal areas of Europe and United States is Onchocerca lupi, and Onchocerca volvulus, the anthroponotic species, may be found among people who had lived in endemic areas of...

Leishmaniasis is a vectorborne disease that can infect humans, dogs, and other mammals. We identified one of its causative agents, Leishmania infantum, in a dog born in California, USA, demonstrating potential for autochthonous infections in this country. Our finding bolsters the need for improved leishmaniasis screening practices in the United Sta...

In the United States, phlebotomine sand flies carrying Leishmania (Leishmania) mexicana are endemic along the southern border. However, relatively little is known about the enzootic and zoonotic transmission of L. (L.) mexicana within the United States, and autochthonous cases of the consequent disease are rarely reported. We investigated an atypic...

This section focuses on potential hazards of working in settings in which exposures to viable parasites could occur, and approaches to decrease the likelihood of accidental exposures. Available data are limited; the perspective provided is based on review of the literature regarding reported cases of occupationally-acquired parasitic infections, av...

Some recent studies suggest ongoing transmission of parasitic diseases in the American South; however, surveys in Mississippi children are lacking. We enrolled 166 children (median age 8 years, range 4–13 years) from the Mississippi Delta region and carried out multi-parallel real-time polymerase chain reaction (PCR) for Necator americanus, Ascaris...

This Special Issue of Tropical Medicine and Infectious Disease is dedicated to the life and work of Emeritus Professor John Marsden Goldsmid [...]

Background Nucleic acid amplification tests (NAATs) are increasingly being used as diagnostic tools for soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, Necator americanus, Ancylostoma duodenale and A. ceylanicum), Strongyloides stercoralis and Schistosoma in human stool. Currently, there is a large diversity of NAATs be...

As COVID-19 spreads through the world, most cases to date are in middle- and high-income nations. The impact on resource-poor nations remains unknown. Amongst many factors likely to affect the impact of COVID-19 in these areas, co-infections need to be considered. Here, we discuss whether the immunomodulatory effects of helminth infections may affe...

(Abstracted from N Engl J Med 2019;381:2569–2580) Next-generation sequencing (NGS) can quickly characterize microbes and help scientists understand how they are transmitted. Public health agencies have been utilizing pathogen genomics in order to better identify the cause of infectious diseases.

Human infection with larvae of canine and feline roundworms belonging to the genus Toxocara can lead to devastating visceral, neural or ocular larvae migrans disease. However, such overt disease represents a fraction of cases. Far more common is covert toxocariasis, a less severe, but clinically symptomatic form of disease, and those who are expose...

Toxocara species are intestinal helminths of dogs and cats, the larval stages of which may infect humans and cause severe neural, ocular and visceral larva migrans disease. Such cases of severe overt disease represent only a small fraction of the of the US population who have been exposed and infected with Toxocara, subsequently developing IgG anti...

As training in helminthology has declined in the medical microbiology curriculum, many rare species of zoonotic cestodes have fallen into obscurity. Even among specialist practitioners, knowledge of human intestinal cestode infections is often limited to three genera, Taenia, Hymenolepis and Dibothriocephalus. However, five genera of uncommonly enc...

We describe a second case of human infection caused by Thelazia gulosa (the cattle eye worm), likely acquired in California. For epidemiologic purposes, it is important to identify all Thelazia recovered from humans in North America to the species level.

Rapid advances in DNA sequencing technology ("next-generation sequencing") have inspired optimism about the potential of human genomics for "precision medicine." Meanwhile, pathogen genomics is already delivering "precision public health" through more effective investigations of outbreaks of foodborne illnesses, better-targeted tuberculosis control...

A Bangladeshi patient with prior travel to Saudi Arabia was hospitalized in the United States for a presumptive liver abscess. Praziquantel was administered following a positive Schistosoma antibody test. Ten days later, a subadult worm migrated to the skin surface and was identified morphologically as Gnathostoma spinigerum. This case highlights t...

Infections with commonly occurring Australian arthropod-borne arboviruses such as Ross River virus (RRV) and Barmah Forest virus (BFV) are diagnosed routinely by pathology laboratories in Australia. Others, such as Murray Valley encephalitis (MVEV) and Kunjin (KUNV) virus infections may be diagnosed by specialist reference laboratories. Although Al...