Dissertation•
Molecular epidemiology of rodent-, shrew- and bat-borne hantaviruses in Mbeya region, Tanzania
01 Mar 2019-
TL;DR: A Thesis Submitted in Partial Fulfilment for the Requirements of the Master’s in Life Sciences of the Nelson Mandela African Institution of Science and Technology.
Abstract: A Thesis Submitted in Partial Fulfilment for the Requirements of the Master’s in Life Sciences of the Nelson Mandela African Institution of Science and Technology
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01 Jan 2009
TL;DR: In what case do you like reading so much? What about the type of the vaccines for biodefense and emerging and neglected diseases by alan dt barrett 2009 01 06 book? The needs to read? Well, everybody has their own reason why should read some books as discussed by the authors.
Abstract: In what case do you like reading so much? What about the type of the vaccines for biodefense and emerging and neglected diseases by alan dt barrett 2009 01 06 book? The needs to read? Well, everybody has their own reason why should read some books. Mostly, it will relate to their necessity to get knowledge from the book and want to read just to get entertainment. Novels, story book, and other entertaining books become so popular this day. Besides, the scientific books will also be the best reason to choose, especially for the students, teachers, doctors, businessman, and other professions who are fond of reading.
87 citations
TL;DR: It is suggested that the authorities at international ports should strengthen port sanitation control and decrease density of rodent population in ports area, and focus on rodent elimination by drug, to reduce the chance of contact between human and rodents and reduce the risk of human infection.
Abstract: Hantavirus is a category II notifiable disease in Taiwan. The aim of this study is to investigate the rodent population, distribution, and seropositive rate of Hantavirus in its rodent vector. During the period from Jan 1, 2010 to Dec 31, 2013, a total of 3,088 rodents, which can be categorized into 6 species in 4 genera, 2 families, and 2 orders have been captured at international ports in Taiwan. The dominate species of the captured rodents were the species of Rattus norvegicus, followed by, in percentage descending order, Suncus murinus, Rattus losea, Rattus tanezumi, Bandicota indica and Musmus culus. The number of rodents captured were not differ greatly by year, indicated that the rodents now reached to a stable population in ports area. The detected Hantavirus seropositive rate was highest in R. norvegicus (11.52%), followed by R. tanezumi (2.60%), S. murinus (1.01%), and R. losea (0.25%). The average Hantavirus seropositive rate in rodents captured at international ports during Jan 2010 to Dec 2013 was 6.02 % (0.00%- 36.55%), except none detected in two ports (Taipei seaport and Hualian seaport). Although we have been monitoring the infection of hantavirus in rodents at international ports during the period from Nov 2004 to Dec 2013, but the hantavirus seropositive rate in rodent population was still presented at a certain level. The risk of human infection by hantavirus when in contact with excreta or secretions from infected rodents is high. We suggested that the authorities at international ports should strengthen port sanitation control and decrease density of rodent population in ports area, and focus on rodent elimination by drug, thus reduce the chance of contact between human and rodents, furthermore reduce the risk of human infection.
1 citations
1 citations
TL;DR: In this article , the authors investigated the circulation of rodent-borne hantavirus in peridomestic rodents and shrews in two semi-arid ecologies within the Kenyan Rift Valley.
Abstract: Hantaviruses are zoonotic rodent-borne viruses that are known to infect humans and cause various symptoms of disease, including hemorrhagic fever with renal and cardiopulmonary syndromes. They have a segmented single-stranded, enveloped, negative-sense RNA genome and are widely distributed. This study aimed to investigate the circulation of rodent-borne hantaviruses in peridomestic rodents and shrews in two semi-arid ecologies within the Kenyan Rift Valley. The small mammals were trapped using baited folding Sherman traps set within and around houses, then they were sedated and euthanatized through cervical dislocation before collecting blood and tissue samples (liver, kidney, spleen, and lungs). Tissue samples were screened with pan-hantavirus PCR primers, targeting the large genome segment (L) encoding the RNA-dependent RNA polymerase (RdRp). Eleven of the small mammals captured were shrews (11/489, 2.5%) and 478 (97.5%) were rodents. A cytochrome b gene-based genetic assay for shrew identification confirmed the eleven shrews sampled to be Crocidura somalica. Hantavirus RNA was detected in three (3/11, 27%) shrews from Baringo County. The sequences showed 93–97% nucleotide and 96–99% amino acid identities among each other, as well as 74–76% nucleotide and 79–83% amino acid identities to other shrew-borne hantaviruses, such as Tanganya virus (TNGV). The detected viruses formed a monophyletic clade with shrew-borne hantaviruses from other parts of Africa. To our knowledge, this constitutes the first report published on the circulation of hantaviruses in shrews in Kenya.
References
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TL;DR: In this review sample size calculation for most frequently used study designs are mentioned and for genetic and microbiological studies readers are requested to read other sources.
Abstract: Calculation of exact sample size is an important part of research design. It is very important to understand that different study design need different method of sample size calculation and one formula cannot be used in all designs. In this short review we tried to educate researcher regarding various method of sample size calculation available for different study designs. In this review sample size calculation for most frequently used study designs are mentioned. For genetic and microbiological studies readers are requested to read other sources.
1,623 citations
TL;DR: It is clear that the authors do not know enough about bat biology; they are doing too little in terms of bat conservation; and there remain a multitude of questions regarding the role of bats in disease emergence.
Abstract: Bats (order Chiroptera, suborders Megachiroptera and Microchiroptera) are abundant, diverse, and geographically widespread. These mammals provide us with resources, but their importance is minimized and many of their populations and species are at risk, even threatened or endangered. Some of their characteristics (food choices, colonial or solitary nature, population structure, ability to fly, seasonal migration and daily movement patterns, torpor and hibernation, life span, roosting behaviors, ability to echolocate, virus susceptibility) make them exquisitely suitable hosts of viruses and other disease agents. Bats of certain species are well recognized as being capable of transmitting rabies virus, but recent observations of outbreaks and epidemics of newly recognized human and livestock diseases caused by viruses transmitted by various megachiropteran and microchiropteran bats have drawn attention anew to these remarkable mammals. This paper summarizes information regarding chiropteran characteristics and information regarding 66 viruses that have been isolated from bats. From these summaries, it is clear that we do not know enough about bat biology, that we are doing too little in terms of bat conservation, and that there remain a multitude of questions regarding the role of bats in disease emergence.
1,271 citations
"Molecular epidemiology of rodent-, ..." refers background in this paper
...Bats, rodents and shrews are arguably the most important source of emerging viruses such as Lassa-, Henipa- and Filo-viruses (Calisher et al., 2006)....
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...2 Statement of the Research Problem Bats, rodents and shrews are arguably the most important source of emerging viruses such as Lassa-, Henipa- and Filo-viruses (Calisher et al., 2006)....
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TL;DR: Emerging infectious diseases, Emerging infectious diseases, کتابخانه دیجیتالی دانشگاه علوم پزش
Abstract: Emerging infectious diseases , Emerging infectious diseases , کتابخانه دیجیتالی دانشگاه علوم پزشکی و خدمات درمانی شهید بهشتی
1,182 citations
TL;DR: Current concepts regarding the ecology of and disease associated with these serious human pathogens are presented and an integration of the ecology and evolution of these and other host-virus ecosystems through modeling and hypothesis-driven research with the risk of emergence, host switching/spillover, and disease transmission to humans.
Abstract: Summary: Hantaviruses are enzootic viruses that maintain persistent infections in their rodent hosts without apparent disease symptoms. The spillover of these viruses to humans can lead to one of two serious illnesses, hantavirus pulmonary syndrome and hemorrhagic fever with renal syndrome. In recent years, there has been an improved understanding of the epidemiology, pathogenesis, and natural history of these viruses following an increase in the number of outbreaks in the Americas. In this review, current concepts regarding the ecology of and disease associated with these serious human pathogens are presented. Priorities for future research suggest an integration of the ecology and evolution of these and other host-virus ecosystems through modeling and hypothesis-driven research with the risk of emergence, host switching/spillover, and disease transmission to humans.
833 citations
"Molecular epidemiology of rodent-, ..." refers background in this paper
...The epidemiological history of Hantavirus started from the discovery of Hantaan virus (HNTV) as the causes of Korea hemorrhagic fever (KHF) and this led to the epidemiological studies in rodents and humans (Jonsson et al., 2010)....
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TL;DR: The basic principles of sample size calculations in medical studies are explained briefly and it is shown that underpowered studies are likely to fail to detect the existing treatment effects due to inadequate sample size.
Abstract: Optimum sample size is an essential component of any research. The main purpose of the sample size calculation is to determine the number of samples needed to detect significant changes in clinical parameters, treatment effects or associations after data gathering. It is not uncommon for studies to be underpowered and thereby fail to detect the existing treatment effects due to inadequate sample size. In this paper, we explain briefly the basic principles of sample size calculations in medical studies.
585 citations