scholarly journals Ebola from emergence to epidemic: the virus and the disease, global preparedness and perspectives

2015 ◽  
Vol 9 (05) ◽  
pp. 441-455 ◽  
Author(s):  
Kuldeep Dhama ◽  
Yashpal Singh Malik ◽  
Satya Veer Singh Malik ◽  
Raj Kumar Singh

Humans constantly encounter threats from many infectious, zoonotic, and devastating pathogens. Outbreaks of severe acute respiratory syndrome (SARS), bird flu, and swine flu posing pandemic threats have compelled health agencies to follow global preparedness for combating the emerging deadly pathogens. The outbreak in West Africa of highly contagious Ebola viral disease (EVD) that started in Guinea in December 2013, assumed global proportions to become the largest outbreak of EVD and the most prominent international health concern. With fatality rates of nearly 50%–90%, it has claimed, as of 11 April 2015, 10,619 human lives out of a total of 25,626 cases reported worldwide. Ebola virus (EBOV), a member of Filoviridae family, is associated with severe, often lethal, hemorrhagic fever disease in humans and animals. The animal hosts, including non-human primates and reservoir hosts (fruit bats), play a significant role in transmission and maintenance of EBOV in nature. Although no approved vaccine for the prevention of EVD currently exists, disease control can be greatly enhanced by timely laboratory confirmation through blood tests using enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR). Adherence to strict sanitary and hygienic measures, monitoring and surveillance of EBOV, as well as quarantine checks on international trade, transport, and visitors from affected countries are mandatory to prevent and control the spread of EVD. This review describes the salient properties of EBOV and the development of novel diagnostics, vaccines, and control strategies for this emerging disease of high public health concern and international emergency.

2018 ◽  
Vol 10 (471) ◽  
pp. eaat0944 ◽  
Author(s):  
David Sebba ◽  
Alexander G. Lastovich ◽  
Melody Kuroda ◽  
Eric Fallows ◽  
Joshua Johnson ◽  
...  

Hemorrhagic fever outbreaks such as Ebola are difficult to detect and control because of the lack of low-cost, easily deployable diagnostics and because initial clinical symptoms mimic other endemic diseases such as malaria. Current molecular diagnostic methods such as polymerase chain reaction require trained personnel and laboratory infrastructure, hindering diagnostics at the point of need. Although rapid tests such as lateral flow can be broadly deployed, they are typically not well-suited for differentiating among multiple diseases presenting with similar symptoms. Early detection and control of Ebola outbreaks require simple, easy-to-use assays that can detect and differentiate infection with Ebola virus from other more common febrile diseases. Here, we developed and tested an immunoassay technology that uses surface-enhanced Raman scattering (SERS) tags to simultaneously detect antigens from Ebola, Lassa, and malaria within a single blood sample. Results are provided in <30 min for individual or batched samples. Using 190 clinical samples collected from the 2014 West African Ebola outbreak, along with 163 malaria positives and 233 negative controls, we demonstrated Ebola detection with 90.0% sensitivity and 97.9% specificity and malaria detection with 100.0% sensitivity and 99.6% specificity. These results, along with corresponding live virus and nonhuman primate testing of an Ebola, Lassa, and malaria 3-plex assay, indicate the potential of the SERS technology as an important tool for outbreak detection and clinical triage in low-resource settings.


2021 ◽  
Author(s):  
Zejin Ou ◽  
Huan He ◽  
Danfeng Yu ◽  
Yongzhi Li ◽  
Yuanhao Liang ◽  
...  

Abstract Background HIV/AIDS is a critical public health concern worldwide. This article aimed to demonstrate th trends of HIV/AIDS burden from 1990 to 2019.Methods Data was extracted from the Global Burden of Disease study (GBDs) 2019. Estimated annual percentage change (EAPC) and age-standardized rate (ASR) were estimated to quantify the trends at global, regional and national levels.Results During the period 1990-2004, the trend in incidence of HIV/AIDS was stable globally. Whereas the trends in prevalence, death and disability-adjusted life years (DALYs) had pronounced increasing trends, with the respective EAPCs were 7.47 (95%confidence interval [CI]: 5.84 to 9.12), 10.85(95%CI: 8.90 to 12.84), and 10.40(95%CI: 8.47 to 12.36). Meanwhile, the pronounced increasing trends were seen in low-resource settings, particularly that of death in Oceania and South Asia, in which the respective EAPCs were 44.76 (95%CI: 40.81 to 48.82) and 40.82 (95%CI: 34.31 to 47.64). However, the global trends in incidence, death and DALYs of HIV/AIDS pronouncedly decreased from 2005 to 2019, with the respective EAPCs were −2.68(95%CI: −2.82 to −2.53), −6.73(95%CI: −6.98 to −6.47) and −6.75(95%CI: −6.95 to −6.54). Whereas prevalence showed increasing trend (EAPC: 0.71, 95%CI: 0.54 to 0.87). Decreasing trends of HIV/AIDS were observed in most regions and countries, particularly that of death and DALYs in Burundi respectively were −15.28 (95%CI: −16.08 to −14.47) and −15.07 (95%CI: −15.79 to −14.33). Conclusions Decreasing trends of HIV/AIDS were observed worldwide over the past 15 years. However, HIV/AIDS remains one of the most critical causes of health loss worldwide, which emphasized the effective prevention and control strategies.


2014 ◽  
Vol 59 (No. 12) ◽  
pp. 637-640 ◽  
Author(s):  
BY Jung ◽  
SH Lee ◽  
D. Kwak

Neospora caninum is a protozoan parasite that causes abortion in ruminants, including goats. The objective of the present study was to determine the seroprevalence of N. caninum in native Korean goats (Capra hircus coreanae). A commercial enzyme-linked immunosorbent assay kit was used to analyse 464 serum samples for the presence of N. caninum antibodies. Four samples (0.9%, 95% confidence intervals &ndash; CI: 0.0&ndash;1.7) were found to be positive for N. caninum antibodies. The seroprevalence was analysed according to age (less than to one year, young; more than or equal one year, adult; and unknown), sampling season (April to September, warm; October to March, cold), and region (northern, central, and southern). However, there were no statistically significant differences in seroprevalence according to age, season, and region (P &gt; 0.05). This is the first report on the seroprevalence of N. caninum in native Korean goats. The results of this study indicate a nationwide distribution of N. caninum among goats, with a relatively low prevalence. Therefore, the implementation of integrated control strategies as well as measures for prevention and control of N. caninum infection among goats is recommended.


Author(s):  
Bipin Acharya ◽  
Wei Chen ◽  
Zengliang Ruan ◽  
Gobind Pant ◽  
Yin Yang ◽  
...  

Being a globally emerging mite-borne zoonotic disease, scrub typhus is a serious public health concern in Nepal. Mapping environmental suitability and quantifying the human population under risk of the disease is important for prevention and control efforts. In this study, we model and map the environmental suitability of scrub typhus using the ecological niche approach, machine learning modeling techniques, and report locations of scrub typhus along with several climatic, topographic, Normalized Difference Vegetation Index (NDVI), and proximity explanatory variables and estimated population under the risk of disease at a national level. Both MaxEnt and RF technique results reveal robust predictive power with test The area under curve (AUC) and true skill statistics (TSS) of above 0.8 and 0.6, respectively. Spatial prediction reveals that environmentally suitable areas of scrub typhus are widely distributed across the country particularly in the low-land Tarai and less elevated river valleys. We found that areas close to agricultural land with gentle slopes have higher suitability of scrub typhus occurrence. Despite several speculations on the association between scrub typhus and proximity to earthquake epicenters, we did not find a significant role of proximity to earthquake epicenters in the distribution of scrub typhus in Nepal. About 43% of the population living in highly suitable areas for scrub typhus are at higher risk of infection, followed by 29% living in suitable areas of moderate-risk, and about 22% living in moderately suitable areas of lower risk. These findings could be useful in selecting priority areas for surveillance and control strategies effectively.


bionature ◽  
2019 ◽  
Vol 19 (2) ◽  
Author(s):  
Suci Wulandhani ◽  
A. Bida Purnamasari ◽  
Ryan Humardani Syam Pratomo

Abstract. Dengue hemorrhagic fever (DHF) is a disease caused by dengue virus infection. One symptom of dengue virus infection is high fever and headache. Dengue virus is a virus from the genus Flavivirus, family of Flaviviridae. This dengue fever is a dangerous viral disease because it can cause sufferers to die in a very short time / several days. The existence and population density are often associated with transmission, endemicity and Extraordinary Events (EE) of DHF. Disease mapping by utilizing digital technology to support epidemiological investigations and also as a tool to monitor regional conditions for dengue disease. The purpose of this study was to determine efforts to prevent and control dengue disease by mapping. The results of the study show that mapping can be seen as increasing and decreasing the number of cases of dengue disease so that it can assist in data management and reporting of information to monitor areas at risk of contracting dengue disease. Suggestions given need to do further research using other variables that are the cause of the high rate of dengue cases, so that it can be utilized by related agencies as the basis of the information system supporting the decision on preventive measures to combat dengue. Keywords: prevention and control, DHF, mapping.


2020 ◽  
Vol 71 (3) ◽  
pp. 2243
Author(s):  
WAFAA A ABD EL-GHANY

Rabbit hemorrhagic disease (RHD) is considered as one of the most important viral diseases that affects and threatens rabbit’s flocks. This disease has affected rabbits since mid-1980. Two epidemics of RHD had been discovered; the first was in mid-1980 and known as classical RHD virus (RHDV), while the second was in 2011 and described as variant virus (RHDVb/RHDV2). Domestic and wild rabbits are susceptible to RHD. All ages can be affected, but adults are more susceptible to young kitten. RHD is presented in three forms; per-acute, acute and subacute or chronic form. Mortality rate is usually high especially in per-acute and acute stages and it is associated with disseminated intravascular coagulopathy and necrotic hepatitis. The main lesions have been observed in the liver, lungs and spleen. Diagnosis of RHD is based on the clinical picture and detection of RHDV or specific antibodies. The prevention and control strategies depend mainly on using of preventive inactivated vaccine together with adoptionof hygienic measures. However, there is no specific treatment of RHDV infection. So, this review article puts a spot light on RHD regarding the epidemiology, the clinical and laboratory diagnosis as well as the prevention and control strategies with a special reference to Egyptian situation.


Author(s):  
Michael B. A. Oldstone

This chapter highlights three of the recently identified viruses: Lassa fever virus, Ebola virus, and hantavirus. All three are equally lethal infectious agents, but they are members of different viral families. They share the ability to cause hemorrhagic fever. Once infected with any of these viruses, the victim soon suffers profuse breaks in small blood vessels, causing blood to ooze from the skin, mouth, gastrointestinal tract, and rectum. Internally, blood flows into the pleural cavity where the lungs are located, into the pericardial cavity surrounding the heart, into the abdomen, and into organs like the liver, kidney, heart, spleen, and lungs. Eventually, this uncontrolled bleeding causes unconsciousness and death. There is currently no established vaccine to prevent these potential plagues, although several are in various stages of development, and an Ebola vaccine is currently undergoing trial in Africa. The chapter also considers a newly emerging and undefined but serious disease of children, which arose primarily in 2014. Based on clinical observations, the disease is identified by the signs and symptoms of acute flaccid myelitis.


Author(s):  
Yinbiao Wang ◽  
Xiao Liu ◽  
Xingdong Yang ◽  
Ling Tao ◽  
Pengwei Xu ◽  
...  

Ebola hemorrhagic fever is among severe and fatal viral hemorrhagic fevers and a global health concern. Here, we constructed a prokaryotic expression plasmid pET32a-VP40 for the large-scale expression of VP40 in E. coli Rosetta (DE3) cells. Water-soluble protein was obtained through optimization of the expression temperature, time and IPTG concentrations. After purification through Ni-NTA affinity chromatography, VP40 protein was applied to immunize rabbit for the analysis of immunogenicity and the production of polyclonal antibodies. Western blot showed that recombinant VP40 protein could be recognized by anti-His6-tag MAb and rabbit polyclonal antibodies against VP40 protein. Polyclonal antibody titers in ELISA reached 1:51200. Moreover, the produced rabbit polyclonal antibodies could react specifically with VP40 protein expressed in BHK-21 cells by transfection of pcDNA-eGFP-VP40 in IPMA. The preparation of VP40 protein and its polyclonal antibodies laid the basis for developing immunoassays for EBOV detection.


2007 ◽  
Vol 70 (5) ◽  
pp. 1246-1248 ◽  
Author(s):  
E. WILHELM ◽  
F. HILBERT ◽  
P. PAULSEN ◽  
F. J. M. SMULDERS ◽  
W. ROSSMANITH

Salmonellosis is an important foodborne infection in industrialized and developing countries. Especially for human Salmonellosis caused by Salmonella enterica serovar Typhimurium, pigs and pork are the major sources of infection. Mitigation and control strategies that result from surveillance programs attempt to reduce or even eradicate Salmonella in pork to lower consumers' risks. The methodology for Salmonella screening in pigs is generally based on antibody detection at slaughter with meat juice as the sample matrix. The instructions to most commercial enzyme-linked immunosorbent assay (ELISA) kits for the detection of Salmonella antibodies state that their product is suitable for antibody detection in meat juice and sera. In the present study, we show that it is essential to recalculate the percent optical density (OD%) data obtained from meat juice by the ELISA (IDEXX HerdCheck swine Salmonella) by the following regression equation: OD%sera = −70.5587 + 128.1490/{1 + exp[(−18.8969 − OD%meat juice)/27.6032]}1.1771, r = 0.87, to compare results with those obtained from sera. By this regression equation, we were able to compare the Salmonella antibody levels (classified as &lt;10, 10 to &lt;20, 20 to &lt;40, and ≥40 OD%) for sows, growers, and slaughter pigs. We identified significantly higher numbers of growers with lower OD% levels than for sows and slaughter pigs. Without a recalculation of the meat juice results, the higher fraction of samples with low OD% values led to an underestimation of the actual seroprevalence.


Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 963
Author(s):  
Herman M. Chambaro ◽  
Michihito Sasaki ◽  
Edgar Simulundu ◽  
Isaac Silwamba ◽  
Yona Sinkala ◽  
...  

Bluetongue (BT) is an arthropod-borne viral disease of ruminants with serious trade and socio-economic implications. Although the disease has been reported in a number of countries in sub-Saharan Africa, there is currently no information on circulating serotypes and disease distribution in Zambia. Following surveillance for BT in domestic and wild ruminants in Zambia, BT virus (BTV) nucleic acid and antibodies were detected in eight of the 10 provinces of the country. About 40% (87/215) of pooled blood samples from cattle and goats were positive for BTV nucleic acid, while one hartebeest pool (1/43) was positive among wildlife samples. Sequence analysis of segment 2 revealed presence of serotypes 3, 5, 7, 12 and 15, with five nucleotypes (B, E, F, G and J) being identified. Segment 10 phylogeny showed Zambian BTV sequences clustering with Western topotype strains from South Africa, intimating likely transboundary spread of BTV in Southern Africa. Interestingly, two Zambian viruses and one isolate from Israel formed a novel clade, which we designated as Western topotype 4. The high seroprevalence (96.2%) in cattle from Lusaka and Central provinces and co-circulation of multiple serotypes showed that BT is widespread, underscoring the need for prevention and control strategies.


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