Ph.D. student, Faculty of Tropical Medicine, Mahidol University


One Health Application in intestinal parasite prevention and control in endemic area of Thailand.

Despite the high burden, intestinal parasite infection is severely neglected. In our study, we utilized the One Health approach to explore the true burden and contributing risk factors of intestinal parasite infection in immigrant communities in Thai-Myanmar border, including possible zoonotic transmission, environmental factors, and perceptions of stakeholders. The result of our study was summarized into a Policy Brief and submitted to Thai Ministry of Interior, Ministry of Public Health, and local authorities for further strategic planning of target-specific solutions to reduce disease burden in this area.


Viral and vector zoonotic exploitation of a homo-sociome memetic complex.

Abstract: As most newly characterized emerging infectious diseases are considered to be zoonotic, a modern pre-eminence ascribed within this classification lies clearly within the viral taxonomic realm. In particular, RNA viruses deserve special concern given their documented impact on conservation biology, veterinary medicine and public health, with an unprecedented ability to promote an evolutionary host-pathogen arms race from the ultimate infection and immunity perspective. However, besides the requisite molecular/gross anatomical and physiological bases for infectious diseases to transmit from one host to another, both viral pathogens and their reservoirs/vectors exploit a complex anthropological, cultural, historical, psychological and social suite that specifically defines the phylodynamics within Homo sapiens, unlike any other species. Some of these variables include the ecological benefits of living in groups, decisions on hunting and foraging behaviours and dietary preferences, myths and religious doctrines, health economics, travel destinations, population planning, political decisions on agricultural product bans and many others, in a homo-sociome memetic complex. Taken to an extreme, such complexities elucidate the underpinnings of explanations as to why certain viral zoonoses reside in neglected people, places and things, whereas others are chosen selectively and prioritized for active mitigation. Canine-transmitted rabies serves as one prime example of how a neglected viral zoonosis may transition to greater attention on the basis of renewed advocacy, social media, local champions and vested international community engagement. In contrast, certain bat-associated and arboviral diseases suffer from basic ignorance and perpetuated misunderstanding of fundamental reservoir and vector ecology tenets, translated into failed control policies that only exacerbate the underlying environmental conditions of concern. Beyond applied biomedical knowledge, epidemiological skills and biotechnical abilities alone, if a homo-sociome memetic complex approach is also entertained in a modern transdisciplinary context, neglected viral zoonosis may be better understood, controlled, prevented and possibly eliminated, in a more holistic One Health context.

Pub.: 15 Mar '15, Pinned: 31 Jul '17

A need for One Health approach - lessons learned from outbreaks of Rift Valley fever in Saudi Arabia and Sudan.

Abstract: Rift Valley fever (RVF) is an emerging viral zoonosis that impacts human and animal health. It is transmitted from animals to humans directly through exposure to blood, body fluids, or tissues of infected animals or via mosquito bites. The disease is endemic to Africa but has recently spread to Saudi Arabia and Yemen. Our aim was to compare two major outbreaks of RVF in Saudi Arabia (2000) and Sudan (2007) from a One Health perspective.Using the terms 'Saudi Arabia', 'Sudan', and 'RVF', articles were identified by searching PubMed, Google Scholar, and web pages of international organizations as well as local sources in Saudi Arabia and Sudan.The outbreak in Saudi Arabia caused 883 human cases, with a case fatality rate of 14% and more than 40,000 dead sheep and goats. In Sudan, 698 human cases of RVF were recognized (case fatality, 31.5%), but no records of affected animals were available. The ecology and environment of the affected areas were similar with irrigation canals and excessive rains providing an attractive habitat for mosquito vectors to multiply. The outbreaks resulted in livestock trade bans leading to a vast economic impact on the animal market in the two countries. The surveillance system in Sudan showed a lack of data management and communication between the regional and federal health authorities, while in Saudi Arabia which is the stronger economy, better capacity and contingency plans resulted in efficient countermeasures. Studies of the epidemiology and vectors were also performed in Saudi Arabia, while in Sudan these issues were only partly studied.We conclude that a One Health approach is the best option to mitigate outbreaks of RVF. Collaboration between veterinary, health, and environmental authorities both on national and regional levels is needed.

Pub.: 08 Feb '14, Pinned: 31 Jul '17

Evaluation of the accuracy of parasitological techniques for the diagnosis of intestinal parasites in cats.

Abstract: The accuracy of the parasitological techniques of Willis, Hoffman-Pons-Janer or Lutz (HPLJ), Sheather and Faust was evaluated in fecal samples from stray cats caught by the Zoonosis Control Center in Goiânia, Goiás, Brazil. These four techniques were applied separately to analyze 154 fecal samples, and their accuracy was analyzed based on an evaluation of their sensitivity, specificity, positive and negative predictive values, and Kappa index, resulting in the selection of the Willis technique as the nominal gold standard. Of the 154 samples, 115 (74.68%) tested positive for intestinal parasites. The analysis of the frequency of positivity indicated that the HPLJ technique detected 86.1% of the positive samples and was the closest to the gold standard. The analysis of the accuracy of the techniques was evaluated using the most prevalent parasites. The Sheather technique showed the highest accuracy in the detection of Ancylostomatidae, while the Sheather and HPLJ techniques showed similar accuracies in the detection of Cystoisospora spp. when compared to the gold standard. Lastly, the Faust technique showed the highest accuracy in the detection of Toxoplasma gondii when compared to the gold standard. This study underscores the importance of combining parasitological techniques in the diagnosis of intestinal parasites in cats.

Pub.: 23 Dec '15, Pinned: 31 Jul '17

A prospective view of animal and human Fasciolosis.

Abstract: Fasciolosis, a food-borne trematodiasis, results following infection with the parasites, Fasciola hepatica and Fasciola gigantica. These trematodes greatly affect the global agricultural community, infecting millions of ruminants worldwide and causing annual economic losses in excess of US $3 billion. Fasciolosis, an important zoonosis, is classified by WHO as a neglected tropical disease with an estimated 17 million people infected and a further 180 million people at risk of infection. The significant impact on agriculture and human health, together with the increasing demand for animal-derived food products to support global population growth demonstrate that fasciolosis is a major One Health problem. This review details the problematic issues surrounding fasciolosis control, including drug resistance, lack of diagnosis, and the threat that hybridisation of the Fasciola species poses to future animal and human health. We discuss how these parasites may mediate their long-term survival through regulation and modulation of the host immune system, by altering the host immune homeostasis and/or by influencing the intestinal microbiome particularly in respect to concurrent infections with other pathogens. Large genome, transcriptome and proteomic datasets are now available to support an integrated One Health approach to develop novel diagnostic and control strategies for both animal and human disease. This article is protected by copyright. All rights reserved.

Pub.: 18 Jun '16, Pinned: 31 Jul '17

Prevalence of intestinal parasites and molecular characterization of Giardia duodenalis from dogs in La Habana, Cuba

Abstract: Giardia duodenalis is a worldwide protozoan parasite that infects humans and other mammals including dogs. Due to the risk of zoonotic transmission between dogs and humans, we aimed in this study to determine the prevalence of the intestinal parasites and the distribution of assemblages of G. duodenalis among dogs analysed. A descriptive cross-sectional study was carried out in La Habana from June 2014 to March 2015 in the Zoonosis Unit of La Lisa municipality. A total of 98 dogs were analysed by three different techniques (microscopy with faecal concentration, Enzyme-Linked ImmunoSorbent Assay, and Polymerase Chain Reaction) in order to detect Giardia in stool samples. Out of 98 dogs studied, 43 (43.9%) were infected with intestinal parasites. The zoonotic parasites Ancylostoma caninum (21.4%), Trichuris vulpis (16.3%) and the protozoan Giardia duodenalis (11.2%) were the most prevalent parasites. In regards to the G. duodenalis, seven dogs were positive by microscopy after faecal concentration, nine by NOVITEC® Giardia Microplate Assay, and ten and eleven samples were amplified by the β-giardin and SSU-RNA PCRs, respectively. After PCR sequence analysis of both genes only zoonotic assemblages (A and B) were detected. The SSU-RNA sequence results revealed a distribution of 8 assemblage A and 4 assemblage B, whereas only assemblage A were identified by the β-giardin analysis. Among subassemblage classification by β-giardin phylogenetic tree, four isolates showed an AI pattern and one isolate displayed an AII distribution. Mixed infections were detected in three isolates. These findings highlight the risk of zoonotic transmission of Giardia duodenalis between dogs and humans.

Pub.: 31 Jan '17, Pinned: 31 Jul '17

Prevalence and genetic characterization of Cryptosporidium species and Giardia duodenalis in lambs in Oromia Special Zone, Central Ethiopia.

Abstract: Cryptosporidium and Giardia duodenalis are gastro-intestinal parasites that infect human and animals worldwide. Both parasites share a broad host range and are believed to be zoonosis. The aim of this study was to identify the species of Cryptosporidium and assemblages of G. duodenalis in lambs and to elucidate their role in zoonotic transmission.A total of 389 fecal samples were collected from lambs and screened by microscopy and nested PCR targeting the small-subunit ribosomal RNA for Cryptosporidium; and the small-subunit ribosomal RNA, triose phosphate isomerase, β-giardin, and glutamate dehydrogenase genes for G. duodenalis. The prevalence of Cryptosporidium and G. duodenalis was 2.1% (8/389) and 2.6% (10/389), respectively. The infection rate at the three study sites ranged from 1.3 to 3.1% for Cryptosporidium and 1.6 to 3.9% for G. duodenalis; but variation was not statistically significant (p > 0.05). The finding also showed that there is no sex and age group associated difference in the occurrence of Cryptosporidium and G. duodenalis infections in lambs. Sequence analysis revealed that lambs were mono-infection with C. ubiquitum and G. duodenalis assemblage E. The analysis also indicated the presence of genetic variation within isolates of assemblage E; with 4 of them are novel genotypes at the small-subunit ribosomal RNA, β-giardin, and glutamate dehydrogenase genes.The findings of the current study showed that lambs are capable of harboring C. ubiquitum and G. duodenalis assemblage E. This finding suggests that lambs might be sources for potentially zoonotic Cryptosporidium species. This was first molecular study in lambs and contributes to a better understanding of the epidemiology of Cryptosporidium and G. duodenalis in central Ethiopia.

Pub.: 18 Jan '17, Pinned: 31 Jul '17