Showing items 1 - 20 of 49

A molecular survey of tick-borne pathogens from ticks collected in Central Queensland

- Chalada, Melissa, Stenos, John, Vincent, Gemma, Barker, Dayana, Bradbury, Richard

  • Authors: Chalada, Melissa , Stenos, John , Vincent, Gemma , Barker, Dayana , Bradbury, Richard
  • Date: 2018
  • Type: Text , Journal article
  • Relation: Vector-borne and zoonotic diseases Vol. 18, no. 3 (2018), p. 151-163
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  • Description: Central Queensland (CQ) is a large and isolated, low population density, remote tropical region of Australia with a varied environment. The region has a diverse fauna and several species of ticks that feed upon that fauna. This study examined 518 individual ticks: 177 Rhipicephalus sanguineus (brown dog tick), 123 Haemaphysalis bancrofti (wallaby tick), 102 Rhipicephalus australis (Australian cattle tick), 47 Amblyomma triguttatum (ornate kangaroo tick), 57 Ixodes holocyclus (paralysis tick), 9 Bothriocroton tachyglossi (CQ short-beaked echidna tick), and 3 Ornithodoros capensis (seabird soft tick). Tick midguts were pooled by common host or environment and screened for four genera of tick-borne zoonoses by PCR and sequencing. The study examined a total of 157 midgut pools of which 3 contained DNA of Coxiella burnetii, 13 Rickettsia gravesii, 1 Rickettsia felis, and 4 other Rickettsia spp. No Borrelia spp. or Babesia spp. DNA were recovered.

A pilot comparison of fixatives for hookworm real-time polymerase chain reaction

- Bradbury, Richard, Inagaki, Kengo, Singh, Gurbaksh, Agana, Urita, Patterson, Kayla, Malloch, Lacy, Rodriguez, Eduardo, Qvarnstrom, Yvonne, Hobbs, Charlotte

  • Authors: Bradbury, Richard , Inagaki, Kengo , Singh, Gurbaksh , Agana, Urita , Patterson, Kayla , Malloch, Lacy , Rodriguez, Eduardo , Qvarnstrom, Yvonne , Hobbs, Charlotte
  • Date: 2023
  • Type: Text , Journal article
  • Relation: American Journal of Tropical Medicine and Hygiene Vol. 108, no. 2 (2023), p. 335-339
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  • Description: 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 laboratories. We fixed dog feces containing Ancylostoma spp. hookworm eggs in zinc polyvinyl alcohol (Zn-PVA) and Total-Fix, and with 70% ethanol (EtOH) as a control. DNA was extracted at timepoints 11, 33, 64, and 94 days and subjected to Ancylostoma spp. quantitative PCR (qPCR). A linear regression model was created to assess the effect of preservative types on the temporal change of qPCR quantification cycle number (Cq) values, accounting for variances among individual animals. Fixation in 70% EtOH least affected Cq values over 94 days. Total-Fix preservation yielded a higher Cq overall, but there was no significant difference compared with 70% EtOH fixation. Fixation in Zn-PVA resulted in significantly (P < 0.001) higher Cq values than 70% EtOH after only 33 days and loss of amplification at 64 days. Consistent with other helminth fixation studies, 70% EtOH performed well in preserving hookworm DNA over 94 days. Total-Fix provided a comparable alternative for qPCR analysis for hookworm. Fixation in Zn-PVA resulted in loss of detectable hookworm DNA at 64 days, as determined by qPCR. Copyright © 2023 The American Society of Tropical Medicine and Hygiene.

An atypical case of autochthonous cutaneous leishmaniasis associated with naturally infected phlebotomine sand flies in Texas, United States

- Kipp, Evan, de Almeida, Marcos, Marcet, Paula, Bradbury, Richard, Benedict, Theresa, Lin, Wuling, Dotson, Ellen, Hergert, Melinda

  • Authors: Kipp, Evan , de Almeida, Marcos , Marcet, Paula , Bradbury, Richard , Benedict, Theresa , Lin, Wuling , Dotson, Ellen , Hergert, Melinda
  • Date: 2020
  • Type: Text , Journal article
  • Relation: American Journal of Tropical Medicine and Hygiene Vol. 103, no. 4 (2020), p. 1496-1501
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  • Description: 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 atypical case of cutaneous leishmaniasis (CL) caused by L. (L.) mexicana in a patient from central Texas which did not respond to a typical antileishmanial chemotherapy. We also investigated sand fly vectors around the patient's residence. PCR followed by DNA sequencing was used for determination of Leishmania spp., sand fly species, and host blood meal source. The L. (L.) mexicana genotype from the patient was identical to one found in a positive sand fly. Moreover, this genotype presented the same single-nucleotide polymorphisms as other historical CL cases acquired in Texas over the last 10 years, but distinct from those originating in Mexico and Central America. Three sand fly species were identified among the samples analyzed (n = 194), the majority of which were Lutzomyia (Dampfomyia) anthophora (n = 190), of which four specimens tested positive for Leishmania and two blood-fed specimens showed the presence of a human blood meal. This study highlights the complexity of clinical management of CL in a setting where the disease is infrequently encountered. The detection of human blood in Lu. (D.) anthophora is the first documentation of anthropophagy in this species. This is the first report of wild-caught, naturally infected sand flies found in association with an autochthonous case of human leishmaniasis and the specific strain of Leishmania (Leishmania) mexicana in the United States. Copyright © 2020 by The American Society of Tropical Medicine and Hygiene

Ancylostoma ceylanicum

- Colella, Vito, Bradbury, Richard, Traub, Rebecca

Application of a universal parasite diagnostic test to biological specimens collected from animals

- Lane, Meredith, Kashani, Mitra, Barratt, Joel, Qvarnstrom, Yvonne, Yabsley, Michael, Garrett, Kayla, Bradbury, Richard

  • Authors: Lane, Meredith , Kashani, Mitra , Barratt, Joel , Qvarnstrom, Yvonne , Yabsley, Michael , Garrett, Kayla , Bradbury, Richard
  • Date: 2023
  • Type: Text , Journal article
  • Relation: International Journal for Parasitology: Parasites and Wildlife Vol. 20, no. (2023), p. 20-30
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  • Description: 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 of parasitic infections in animals using blood, tissues, and other biological sample types from mammals, birds, and reptiles, known to be infected with helminth, apicomplexan, or pentastomid parasites (confirmed by microscopy or PCR), as well as negative samples. nUPDx confirmed apicomplexan and/or nematode infections in 24 of 32 parasite-positive mammals, while also identifying several undetected coinfections. nUPDx detected infections in 6 of 13 positive bird and 1 of 2 positive reptile samples. When applied to 10 whole parasite specimens (worms and arthropods), nUPDx identified all to the genus or family level, and detected one incorrect identification made by morphology. Babesia sp. infections were detected in 5 of the 13 samples that were negative by other diagnostic approaches. While nUPDx did not detect PCR/microscopy-confirmed trichomonads or amoebae in cloacal swabs/tissue from 8 birds and 2 reptiles due to primer template mismatches, 4 previously undetected apicomplexans were detected in these samples. Future efforts to improve the utility of the assay should focus on validation against a larger panel of tissue types and animal species. Overall, nUPDx shows promise for use in both veterinary diagnostics and wildlife surveillance, especially because species-specific PCRs can miss unknown or unexpected pathogens. © 2022

Ascariasis

- Bradbury, Richard, Kamb, M.

Cross-sectional study of soil-transmitted helminthiases in black belt region of Alabama, USA

- Poole, Claudette, Barker, Troy, Bradbury, Richard, Capone, Drew, Chatham, Amy, Handali, Sukwan, Rodriguez, Eduardo, Qvarnstrom, Yvonne, Brown, Joe

  • Authors: Poole, Claudette , Barker, Troy , Bradbury, Richard , Capone, Drew , Chatham, Amy , Handali, Sukwan , Rodriguez, Eduardo , Qvarnstrom, Yvonne , Brown, Joe
  • Date: 2023
  • Type: Text , Journal article
  • Relation: Emerging Infectious Diseases Vol. 29, no. 12 (2023), p. 2461-2470
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  • Description: 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 helminth eggs. We tested a subset by using molecular techniques: real-time PCR analysis for 5 STH species, TaqMan Array Cards for enteric helminths, and digital PCR for Necator americanus hookworm. We analyzed dried blood spots for Strongyloides stercoralis and Toxocara spp. roundworms by using serologic testing. Despite 12% of our cohort reporting living in homes that directly discharge untreated domestic wastewater, stool testing for STH was negative; however, 5% of dried blood spots were positive for Toxocara spp. roundworms. Survey data suggests substantial numbers of children in this region may be exposed to raw sewage, which is itself a major public health concern. © 2023 Centers for Disease Control and Prevention (CDC). All rights reserved.

Evaluation of the performance of Ortho T. cruzi ELISA test system for the detection of antibodies to Trypanosoma cruzi

- Rivera, Hilda, McAuliffe, Isabel, Aderohunmu, TaLesa, Wiegand, Ryan, Montgomery, Susan, Bradbury, Richard, Handali, Sukwan

  • Authors: Rivera, Hilda , McAuliffe, Isabel , Aderohunmu, TaLesa , Wiegand, Ryan , Montgomery, Susan , Bradbury, Richard , Handali, Sukwan
  • Date: 2022
  • Type: Text , Journal article
  • Relation: Journal of Clinical Microbiology Vol. 60, no. 8 (2022), p.
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  • Description: 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 was cleared by FDA for clinical diagnosis usage. We evaluated this test against the CDC algorithm for chronic Chagas disease. We tested several sets of serum specimens: 104 specimens tested positive for T. cruzi specific antibody and 283 (including 30 specimens positive for antibody to Leishmania spp.) tested negative based on the current CDC chronic T. cruzi infection diagnostic testing algorithm. Concordance of the Ortho T. cruzi ELISA Test System with the CDC algorithm result was 90% (95% CI 87 to 93%) overall and 92% (95% CI 89 to 95%) when excluding Leishmania spp. antibody positive specimens. The cross-reactivity of the Ortho T. cruzi ELISA Test System was 37% to Leishmania spp. serologically positive specimens, 1% to specimens from patients diagnosed with other parasitic infections, and 0% against specimens from a US noninfected population. In conclusion, the Ortho T. cruzi ELISA Test System compares well against the CDC diagnostic algorithm for chronic Chagas disease. The availability of this FDA-cleared assay will improve the chronic Chagas disease diagnosis. © 2022 American Society for Microbiology. All rights reserved.

First international external quality assessment scheme of nucleic acid amplification tests for the detection of schistosoma and soil-transmitted helminths, including strongyloides : A pilot study

- Cools, Piet, van Lieshout, Lisette, Koelewijn, Rob, Addiss, David, Ajjampur, Sitara, Ayana, Mio, Bradbury, Richard, Cantera, Jason, Dana, Daniel, Fischer, Kerstin, Imtiaz, Rubina, Kabagenyi, Joyce, Lok, James, McCarthy, James, Mejia, Rojelio, Mekonnen, Zeleke, Njenga, Sammy, Othman, Nurulhasanah, Shao, Hongguang, Traub, Rebecca, Van Esbroeck, Marjan, Vercruysse, Jozef, Vlaminck, Johnny, Williams, Steven, Verweij, Jaco, van Hellemond, Jaap, Levecke, Bruno

  • Authors: Cools, Piet , van Lieshout, Lisette , Koelewijn, Rob , Addiss, David , Ajjampur, Sitara , Ayana, Mio , Bradbury, Richard , Cantera, Jason , Dana, Daniel , Fischer, Kerstin , Imtiaz, Rubina , Kabagenyi, Joyce , Lok, James , McCarthy, James , Mejia, Rojelio , Mekonnen, Zeleke , Njenga, Sammy , Othman, Nurulhasanah , Shao, Hongguang , Traub, Rebecca , Van Esbroeck, Marjan , Vercruysse, Jozef , Vlaminck, Johnny , Williams, Steven , Verweij, Jaco , van Hellemond, Jaap , Levecke, Bruno
  • Date: 2020
  • Type: Text , Journal article
  • Relation: PLoS Neglected Tropical Diseases Vol. 14, no. 6 (2020), p. 1-19
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  • Description: Background Nucleic acid amplification tests (NAATs) are increasingly being used as diagnostic tools for soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, Necator ameri-canus, Ancylostoma duodenale and A. ceylanicum), Strongyloides stercoralis and Schisto-soma in human stool. Currently, there is a large diversity of NAATs being applied, but an external quality assessment scheme (EQAS) for these diagnostics is lacking. An EQAS involves a blinded process where test results reported by a laboratory are compared to those reported by reference or expert laboratories, allowing for an objective assessment of the diagnostic performance of a laboratory. In the current study, we piloted an international EQAS for these helminths (i) to investigate the feasibility of designing and delivering an EQAS; (ii) to assess the diagnostic performance of laboratories; and (iii) to gain insights into the different NAAT protocols used. Methods and principal findings A panel of twelve stool samples and eight DNA samples was validated by six expert laboratories for the presence of six helminths (Ascaris, Trichuris, N. americanus, Ancylostoma, Strongyloides and Schistosoma). Subsequently this panel was sent to 15 globally dispersed laboratories. We found a high degree of diversity among the different DNA extraction and NAAT protocols. Although most laboratories performed well, we could clearly identify the laboratories that were poorly performing. Conclusions/Significance We showed the technical feasibility of an international EQAS for the NAAT of STHs, Stron-gyloides and Schistosoma. In addition, we documented that there are clear benefits for par-ticipating laboratories, as they can confirm and/or improve the diagnostic performance of their NAATs. Further research should aim to identify factors that explain poor performance of NAATs. © 2020 Cools et al.

Foodborne Trematode Infections

- Sapp, Sarah, Guagliardo, Sarah, Bradbury, Richard

Genomic diversity and antimicrobial resistance among non-typhoidal Salmonella associated with human disease in The Gambia

- Darboe, Saffiatou, Bradbury, Richard, Phelan, Jody, Kanteh, Abdoulie, Muhammad, Abdul-Khalie, Worwui, Archibald, Yang, Shangxin, Nwakanma, Davis, Perez-Sepulveda, Blanca, Kariuki, Samuel, Kwambana-Adams, Brenda, Antonio, Martin

  • Authors: Darboe, Saffiatou , Bradbury, Richard , Phelan, Jody , Kanteh, Abdoulie , Muhammad, Abdul-Khalie , Worwui, Archibald , Yang, Shangxin , Nwakanma, Davis , Perez-Sepulveda, Blanca , Kariuki, Samuel , Kwambana-Adams, Brenda , Antonio, Martin
  • Date: 2022
  • Type: Text , Journal article
  • Relation: Microbial Genomics Vol. 8, no. 3 (2022), p.
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  • Description: 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 the western regions of The Gambia respectively. A total of 93 isolates (64 invasive, 23 gastroenteritis and six other sites) representing a single infection episode were phenotypically tested for antimicrobial susceptibility using the Kirby–Bauer disc diffusion technique. Whole genome sequencing of 100 isolates was performed using Illumina, and the reads were assembled and analysed using SPAdes. The Salmonella in Silico Typing Resource (SISTR) was used for serotyping. SNP differences among the 93 isolates were determined using Roary, and phylogenetic analysis was performed in the context of 495 African strains from the European Nucleotide Archive. Salmonella serovars Typhimurium (26/64; 30.6%) and Enteritidis (13/64; 20.3%) were associated with invasive disease, whilst other serovars were mainly responsible for gastroenteritis (17/23; 73.9%). The presence of three major serovar Enteritidis clades was confirmed, including the invasive West African clade, which made up more than half (11/16; 68.8%) of the genomes. Multidrug resistance was confined among the serovar Enteritidis West African clade. The presence of this epidemic virulent clade has potential for spread of resistance and thus important implications for systematic patient management. Surveillance and epidemiological investigations to inform control are warranted. © 2022 The Authors.

Hookworm

- Bradbury, Richard, Kamb, M.

Hookworm Infection : Necatoriasis and Ancylostomiasis

- Bradbury, Richard

Hookworm Infection in Oceania

- Bradbury, Richard, Traub, Rebecca

  • Authors: Bradbury, Richard , Traub, Rebecca
  • Date: 2016
  • Type: Text , Book chapter
  • Relation: Neglected Tropical Diseases - Oceania Chapter 2 p. 33-68
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  • Description: Hookworm disease and its associated morbidities continue to be a major public health problem in many tropical and subtropical nations and remain endemic throughout the Oceania region. Three species of hookworm cause patent infection in humans in this region: Necator americanus, Ancylostoma duodenale and Ancylostoma ceylanicum. Historical hookworm infection rates of up to 90 % throughout many parts of Oceania have significantly declined; however, the disease remains a major problem requiring ongoing public health intervention. The effectiveness of such interventions is evident in northern Australia, where once widespread hookworm disease is now limited to a few remaining endemic foci of isolated communities in the far north of the country. Outside of Australia, there is limited data available in the literature on hookworm prevalence, but a few recent (since 2000) studies have found hookworm prevalence rates of between 3 and 23 %. Infections with A. caninum, leading to eosinophilic enteritis, and sporadic cases cutaneous larva migrans caused by dermal migration of animal hookworm larva are also reported from several regions. This chapter provides a comprehensive review of both the historical and current literature on species of hookworms infecting humans and the geographical prevalence and distribution of hookworm disease in the Oceania region.

Hospitalizations associated with Strongyloidiasis in the United States, 2003-2018

- Inagaki, Kengo, Bradbury, Richard, Hobbs, Charlotte

  • Authors: Inagaki, Kengo , Bradbury, Richard , Hobbs, Charlotte
  • Date: 2022
  • Type: Text , Journal article
  • Relation: Clinical infectious diseases : an official publication of the Infectious Diseases Society of America Vol. 75, no. 9 (2022), p. 1548-1555
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  • Description: 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 United States. METHODS: We performed a population-based retrospective analysis on strongyloidiasis using the National Inpatient Sample from 2003 to 2018. Geographic distribution of strongyloidiasis associated hospitalization was assessed. Logistic regression was used to identify risk factors associated with strongyloidiasis. RESULTS: We identified 6931 hospitalizations associated with strongyloidiasis during the study period (11.8 per million hospitalizations). The rate of strongyloidiasis was highest in the Northeast US region, including the Middle Atlantic division (47.1 cases per million population; adjusted odds ratio, 2.00 [95% confidence interval: 1.58-2.53]), and the East South Central division (27.5 cases per million; adjusted odds ratio, 2.77 [2.02-3.80]). Older age, male sex, nonwhite race/ethnicity (particularly Hispanic and Asian), nonprivate insurance, and residence in neighborhoods with low median income were also associated with strongyloidiasis. Immunocompromising conditions, particularly human immunodeficiency virus infection, were present in 41.3% of hospitalizations with strongyloidiasis. In-hospital death occurred in 7.8% of patients with strongyloidiasis-associated hospitalization. CONCLUSIONS: Strongyloidiasis-associated hospitalization is rare in the United States but can be associated with increased mortality rate/mortality risk . It occurs more frequently in poor and marginalized populations. Immunocompromised conditions were common among hospitalized patients with strongyloidiasis. Enhanced surveillance efforts are needed to inform health policies for improving the health of at-risk populations. © The Author(s) 2022. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

HTLV-I and strongyloides in Australia : the worm lurking beneath

- Gordon, Catherine, Shield, Jennifer, Bradbury, Richard, Muhi, Stephen, Page, Wendy

  • Authors: Gordon, Catherine , Shield, Jennifer , Bradbury, Richard , Muhi, Stephen , Page, Wendy
  • Date: 2021
  • Type: Text , Book chapter
  • Relation: Advances in Parasitology p. 119-201
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  • Description: 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 infects T-cells thus causing dysregulation of the immune system which has been linked to dissemination and hyperinfection of S. stercoralis leading to bacterial sepsis which can result in death. Both of these pathogens are endemic in Australia primarily in remote communities in Queensland, the Northern Territory, and Western Australia. Other cases in Australia have occurred in immigrants and refugees, returned travellers, and Australian Defence Force personnel. HTLV-I infection is lifelong with no known cure. Strongyloidiasis is a long-term chronic disease that can remain latent for decades, as shown by infections diagnosed in prisoners of war from World War II and the Vietnam War testing positive decades after they returned from these conflicts. This review aims to shed light on concomitant infections of HTLV-I with S. stercoralis primarily in Australia but in the global context as well. © 2021 Elsevier Ltd. *Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Richard Bradbury" is provided in this record**

Human strongyloidiasis : complexities and pathways forward

- Buonfrate, Dora, Bradbury, Richard, Watts, Matthew, Bisoffi, Zeno

  • Authors: Buonfrate, Dora , Bradbury, Richard , Watts, Matthew , Bisoffi, Zeno
  • Date: 2023
  • Type: Text , Journal article , Review
  • Relation: Clinical Microbiology Reviews Vol. 36, no. 4 (2023), p.
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  • Description: 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 asymptomatic or cause long-term symptoms, including malnourishment in children. Low larval output can limit the sensitivity of detection in stool, with serology being effectivebut less sensitive in immunocompromise. Host immunosuppression can trigger catastrophic, fatal hyperinfection/dissemination, where large numbers of larvae pierce the bowel wall and disseminate throughout the organs. Stable disease is effectivelytreated by single-dose ivermectin, with disease in immunocompromised patients treated with multiple doses. Strategies for management include raising awareness, clarifying zoonotic potential, the development and use of effectivediagnostic tests for epidemiological studies and individual diagnosis, and the implementation of treatment programs with research into therapeutic alternatives and medication safety. © 2023 American Society for Microbiology. All rights reserved.

Imported Haycocknema perplexum Infection, United States

- Pritt, Bobbi, Mathison, Blaine, Bradbury, Richard, Liewluck, Teerin, Nicolau, Stefan, O’Horo, John, Grunst, David, Pinto, Marcus, Swanson, Amy, Virk, Abinash

Inactivating effects of common laboratory disinfectants, fixatives, and temperatures on the eggs of soil transmitted helminths

- Kines, Kristine, Fox, Mark, Ndubuisi, MacKevin, Verocai, Guilherme, Cama, Vitaliano, Bradbury, Richard

  • Authors: Kines, Kristine , Fox, Mark , Ndubuisi, MacKevin , Verocai, Guilherme , Cama, Vitaliano , Bradbury, Richard
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Microbiology Spectrum Vol. 9, no. 3 (2021), p.
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  • Description: Soil-transmitted helminths (STH) are important and widespread intestinal pathogens of humans and animals. It is presently unknown which inactivating procedures may be universally effective for safe transport, preservation, and disinfection of STH-contaminated specimens, and this lack of knowledge may expose laboratory staff to higher risk of laboratory-acquired infections (LAI’s). There are limited data on the efficacy of commonly used disinfectants and fecal fixatives for inactivating the eggs of STH. This work tested five disinfectants for surface cleanup, four storage temperature conditions, and six transport/storage fixatives, to inactivate eggs of three species of STH of animal origin (Ascaris suum “roundworm,” Trichuris vulpis “whipworm” and Ancylostoma caninum “hookworm”) as surrogates for human STH. Among disinfectants, exposure to 10% povidone-iodine for $5 min inactivated 100% of the three species tested, while 5 min exposure to 95% ethanol inactivated T. vulpis and A. caninum eggs. All of the fixatives tested had inactivation effects on A. caninum hookworm eggs within 24 h of exposure, except potassium dichromate, which required 48 h. 95% ethanol for $48 h inactivated eggs from all three STH species. Freezing at #220°C for $24 h inactivated eggs of T. vulpis and A. caninum, but only freezing at 280°C for $24 h inactivated .99% eggs, including A. suum. This work provides an evidence base for health and safety guidelines and mitigation strategies for the handling, storage, and disposal of stool samples containing STH eggs in laboratory, health care, childcare, or veterinary settings. IMPORTANCE 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. Previously published work in this area typically focuses on a particular inactivation method, either for a single STH species, or on a subset of closely related species. Because prediagnostic fecal specimens must be regarded as potentially infectious with a mix of species, such information may be of limited utility in a working laboratory. We provide a straightforward summary of storage and disinfection methods that can achieve complete inactivation across a range of STH species, which represents a significant advance for clinical, veterinary and research laboratory biosafety. Copyright © 2021 Kines et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.

Infection of Western Gray Kangaroos (Macropus fuliginosus) with Australian arboviruses associated with human infection

- Gyawali, Narayan, Taylor-Robinson, Andrew, Bradbury, Richard, Potter, Abbey, Aaskov, John

  • Authors: Gyawali, Narayan , Taylor-Robinson, Andrew , Bradbury, Richard , Potter, Abbey , Aaskov, John
  • Date: 2020
  • Type: Text , Journal article
  • Relation: Vector-Borne and Zoonotic Diseases Vol. 20, no. 1 (2020), p. 33-39
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  • Description: More than 75 arboviruses (arthropod-borne viruses) have been identified in Australia. While Alfuy virus (ALFV), Barmah Forest virus (BFV), Edge Hill virus (EHV), Kokobera virus (KOKV), Murray Valley encephalitis virus (MVEV), Sindbis virus (SINV), Ross River virus (RRV), Stratford virus (STRV), and West Nile virus strain Kunjin (KUNV) have been associated with human infection, there remains a paucity of data regarding their respective transmission cycles and any potential nonhuman vertebrate hosts. It is likely that these viruses are maintained in zoonotic cycles involving native animals rather than solely by human-to-human transmission. A serosurvey (n = 100) was undertaken to determine the prevalence of neutralizing antibodies against a panel of Australian arboviruses in western gray kangaroos (Macropus fuliginosus) obtained from 11 locations in the midwest to southwest of Western Australia. Neutralizing antibodies against RRV were detected in 25%, against BFV in 14%, and antibodies to both viruses in 34% of serum samples. The prevalence of antibodies against these two viruses was the same in males and females, but higher in adult than in subadult kangaroos (p < 0.05). Twenty-one percent of samples had neutralizing antibodies against any one or more of the flaviviruses ALFV, EHV, KOKV, MVEV, and STRV. No neutralizing antibodies against SINV and KUNV were detected. If this sample of kangaroo sera was representative of the broader Australian population of macropods, it suggests that they are common hosts for RRV and BFV. The absence or low seroprevalence of antibodies against the remaining arboviruses suggests that they are not prevalent in the region or that kangaroos are not commonly infected with them. The detection of neutralizing antibodies to MVEV requires further investigation as this virus has not been identified previously so far south in Western Australia. © Copyright 2020, Mary Ann Liebert, Inc.