African Swine Fever: Prevalence, Farm Characteristics, Farmer’s Insight and Attitude toward Reporting of African Swine Fever Cases in the Northwest, West, Littoral and Southwest Regions of Cameroon

The African swine fever virus (ASFV) has been circulating in and ravaging the swine industry in Cameroon for decades. Annual ASFV epidemics occur in Cameroon from April to August. With the absence of vaccines and antiviral drugs against this virus, biosecurity has been the only effective control tool available. When properly applied, biosecurity measures allow control of the spread of ASFV and the eventual eradication of this virus. Many outbreak investigations by PCR were effected in Cameroon, with ASFV prevalences ranging from 15.23% to 42.80%. Considering that pre-outbreak studies are not available for Cameroon, the present study aimed at assessing the status of the animals before an outbreak. A two-stage cluster sampling study was conducted from January to March 2020. In this study, the primary unit was the farm and the secondary unit was the individual animals. In all, 97 farms were visited and 277 samples were collected. Pre-outbreak ASFV prevalence, as assessed by PCR, was 9.75%. In parallel, data were collected using a survey of farm characteristics, awareness and attitude of the farmers toward ASF. The survey results showed that 34.1% of the farms were backyard cemented piggeries with the majority having less than 10 pigs (54.1%). The majority of farmers (90.6%) had heard of and knew about the disease caused by ASF. Though 69.4% of the farmers were uninformed on the clinical signs of ASF, 73.6% of them did treat sick pigs presenting similar clinical signs to ASF (with no risk of mortality) with antibiotics, while 79.4% did not treat but sold the pigs presenting clinical signs similar to ASF with an increased risk of mortality. Sixty-three percent of the farmers had reported a case of ASF in the past and believed that reporting was useful and had no negative consequences on other farmers or third parties. We established that poor implementation of biosecurity measures in addition to poor training are contributing factors to the enzootic nature of ASFV in Cameroon and, thus, the spread of ASFV. Hence, pig farmers in Cameroon must be properly trained in ASFV awareness and the impact thereof on pig production. Furthermore, training will also facilitate the successful implementation of biosecurity measures to contain ASFV outbreaks.

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African Swine Fever Laboratory Diagnosis—Lessons Learned from Recent Animal Trials

Pathogens ◽

10.3390/pathogens10020177 ◽

2021 ◽

Vol 10 (2) ◽

pp. 177

Author(s):

Jutta Pikalo ◽

Paul Deutschmann ◽

Melina Fischer ◽

Hanna Roszyk ◽

Martin Beer ◽

...

Keyword(s):

African Swine Fever Virus ◽

Clinical Signs ◽

African Swine Fever ◽

Laboratory Diagnosis ◽

Lessons Learned ◽

Hemorrhagic Disease ◽

Passive Surveillance ◽

Animal Trials ◽

Fit For Purpose ◽

The Impact

African swine fever virus (ASFV) causes a hemorrhagic disease in pigs with high socio-economic consequences. To lower the impact of disease incursions, early detection is crucial. In the context of experimental animal trials, we evaluated diagnostic workflows for a high sample throughput in active surveillance, alternative sample matrices for passive surveillance, and lateral flow devices (LFD) for rapid testing. We could demonstrate that EDTA blood is significantly better suited for early ASFV detection than serum. Tissues recommended by the respective diagnostic manuals were in general comparable in their performance, with spleen samples giving best results. Superficial lymph nodes, ear punches, and different blood swabs were also evaluated as potential alternatives. In summary, all matrices yielded positive results at the peak of clinical signs and could be fit for purpose in passive surveillance. However, weaknesses were discovered for some matrices when it comes to the early phase of infection or recovery. The antigen LFD showed variable results with best performance in the clinical phase. The antibody LFD was quite comparable with ELISA systems. Concluding, alternative approaches are feasible but have to be embedded in control strategies selecting test methods and sample materials following a “fit-for-purpose” approach.

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The impact of African Swine Fever Virus on smallholder village pig production: an outbreak investigation in Lao PDR

10.22541/au.161225061.17768930/v1 ◽

2021 ◽

Author(s):

Nina Matsumoto ◽

J Siengsanan-Lamont ◽

Tariq Halasa ◽

James Young ◽

Michael Ward ◽

...

Keyword(s):

Risk Factors ◽

Wild Boar ◽

Spatial Clustering ◽

African Swine Fever Virus ◽

Lao Pdr ◽

Clinical Signs ◽

African Swine Fever ◽

Fever Virus ◽

Free Ranging ◽

The Impact

African Swine Fever Virus (ASFV) causes a deadly disease of pigs which spread through southeast Asia in 2019. We investigated one of the first outbreaks of ASFV in Lao Peoples Democratic Republic amongst smallholder villages of Thapangtong District, Savannakhet Province. In this study, two ASFV affected villages were compared to two unaffected villages. Evidence of ASFV-like clinical signs appeared in pig herds as early as May 2019, with median epidemic days on 1 and 18 June in the two villages, respectively. Using participatory epidemiology mapping techniques, we found statistically significant spatial clustering in both outbreaks (P < 0.001). Villagers reported known risk factors for ASFV transmission  such as free-ranging management systems and wild boar access  in all four villages. The villagers reported increased pig trader activity from Vietnam before the outbreaks; however, the survey did not determine a single outbreak source. The outbreak caused substantial household financial losses with an average of 9 pigs lost to the disease, and Monte Carlo analysis estimated this to be USD 215 per household. ASFV poses a significant threat to food and financial security in smallholder communities such as Thapangtong, where 40.6% of the district’s population are affected by poverty. This study shows ASFV management in the region will require increased local government resources, knowledge of informal trader activity and wild boar monitoring alongside education and support to address intra-village risk factors such as free-ranging, correct waste disposal and swill feeding.

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The impact of African Swine Fever Virus on smallholder village pig production: an outbreak investigation in Lao PDR

10.22541/au.162105009.94756785/v1 ◽

2021 ◽

Author(s):

Nina Matsumoto ◽

J Siengsanan-Lamont ◽

Tariq Halasa ◽

James Young ◽

Michael Ward ◽

...

Keyword(s):

Risk Factors ◽

Wild Boar ◽

Spatial Clustering ◽

African Swine Fever Virus ◽

Lao Pdr ◽

Clinical Signs ◽

African Swine Fever ◽

Fever Virus ◽

Free Ranging ◽

The Impact

African Swine Fever Virus (ASFV) causes a deadly disease of pigs which spread through southeast Asia in 2019. We investigated one of the first outbreaks of ASFV in Lao Peoples Democratic Republic amongst smallholder villages of Thapangtong District, Savannakhet Province. In this study, two ASFV affected villages were compared to two unaffected villages. Evidence of ASFV-like clinical signs appeared in pig herds as early as May 2019, with median epidemic days on 1 and 18 June in the two villages, respectively. Using participatory epidemiology mapping techniques, we found statistically significant spatial clustering in both outbreaks (P < 0.001). Villagers reported known risk factors for ASFV transmission − such as free-ranging management systems and wild boar access − in all four villages. The villagers reported increased pig trader activity from Vietnam before the outbreaks; however, the survey did not determine a single outbreak source. The outbreak caused substantial household financial losses with an average of 9 pigs lost to the disease, and Monte Carlo analysis estimated this to be USD 215 per household. ASFV poses a significant threat to food and financial security in smallholder communities such as Thapangtong, where 40.6% of the district’s population are affected by poverty. This study shows ASFV management in the region will require increased local government resources, knowledge of informal trader activity and wild boar monitoring alongside education and support to address intra-village risk factors such as free-ranging, incorrect waste disposal and swill feeding.

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Live Attenuated African Swine Fever Viruses as Ideal Tools to Dissect the Mechanisms Involved in Cross-Protection

Viruses ◽

10.3390/v12121474 ◽

2020 ◽

Vol 12 (12) ◽

pp. 1474

Author(s):

Elisabeth Lopez ◽

Juanita van Heerden ◽

Laia Bosch-Camós ◽

Francesc Accensi ◽

Maria Jesus Navas ◽

...

Keyword(s):

Vaccine Development ◽

African Swine Fever Virus ◽

Virulent Strain ◽

Sequence Similarity ◽

Clinical Signs ◽

African Swine Fever ◽

Cross Protection ◽

Sub Saharan Africa ◽

Genotype I ◽

Genotype Ii

African swine fever (ASF) has become the major threat for the global swine industry. Furthermore, the epidemiological situation of African swine fever virus (ASFV) in some endemic regions of Sub-Saharan Africa is worse than ever, with multiple virus strains and genotypes currently circulating in a given area. Despite the recent advances on ASF vaccine development, there are no commercial vaccines yet, and most of the promising vaccine prototypes available today have been specifically designed to fight the genotype II strains currently circulating in Europe, Asia, and Oceania. Previous results from our laboratory have demonstrated the ability of BA71∆CD2, a recombinant LAV lacking CD2v, to confer protection against homologous (BA71) and heterologous genotype I (E75) and genotype II (Georgia2007/01) ASFV strains, both belonging to same clade (clade C). Here, we extend these results using BA71∆CD2 as a tool trying to understand ASFV cross-protection, using phylogenetically distant ASFV strains. We first observed that five out of six (83.3%) of the pigs immunized once with 106 PFU of BA71∆CD2 survived the tick-bite challenge using Ornithodoros sp. soft ticks naturally infected with RSA/11/2017 strain (genotype XIX, clade D). Second, only two out of six (33.3%) survived the challenge with Ken06.Bus (genotype IX, clade A), which is phylogenetically more distant to BA71∆CD2 than the RSA/11/2017 strain. On the other hand, homologous prime-boosting with BA71∆CD2 only improved the survival rate to 50% after Ken06.Bus challenge, all suffering mild ASF-compatible clinical signs, while 100% of the pigs immunized with BA71∆CD2 and boosted with the parental BA71 virulent strain survived the lethal challenge with Ken06.Bus, without almost no clinical signs of the disease. Our results confirm that cross-protection is a multifactorial phenomenon that not only depends on sequence similarity. We believe that understanding this complex phenomenon will be useful for designing future vaccines for ASF-endemic areas.

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Pathogenicity of an African swine fever virus strain isolated in Vietnam and alternative diagnostic specimens for early detection of viral infection

Porcine Health Management ◽

10.1186/s40813-021-00215-0 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Hu Suk Lee ◽

Vuong Nghia Bui ◽

Duy Tung Dao ◽

Ngoc Anh Bui ◽

Thanh Duy Le ◽

...

Keyword(s):

Early Detection ◽

Oral Fluid ◽

African Swine Fever Virus ◽

Fluid Collection ◽

Clinical Signs ◽

African Swine Fever ◽

Post Inoculation ◽

Tissue Samples ◽

Viral Loads ◽

Specimen Collection

Abstract Background African swine fever (ASF), caused by the ASF virus (ASFV), was first reported in Vietnam in 2019 and spread rapidly thereafter. Better insights into ASFV characteristics and early detection by surveillance could help control its spread. However, the pathogenicity and methods for early detection of ASFV isolates from Vietnam have not been established. Therefore, we investigated the pathogenicity of ASFV and explored alternative sampling methods for early detection. Results Ten pigs were intramuscularly inoculated with an ASFV strain from Vietnam (titer, 103.5 HAD50/mL), and their temperature, clinical signs, and virus excretion patterns were recorded. In addition, herd and environmental samples were collected daily. The pigs died 5–8 days-post-inoculation (dpi), and the incubation period was 3.7 ± 0.5 dpi. ASFV genome was first detected in the blood (2.2 ± 0.8) and then in rectal (3.1 ± 0.7), nasal (3.2 ± 0.4), and oral (3.6 ± 0.7 dpi) swab samples. ASFV was detected in oral fluid samples collected using a chewed rope from 3 dpi. The liver showed the highest viral loads, and ear tissue also exhibited high viral loads among 11 tissues obtained from dead pigs. Overall, ASFV from Vietnam was classified as peracute to acute form. The rope-based oral fluid collection method could be useful for early ASFV detection and allows successful ASF surveillance in large pig farms. Furthermore, ear tissue samples might be a simple alternative specimen for diagnosing ASF infection in dead pigs. Conclusions Our data provide valuable insights into the characteristics of a typical ASFV strain isolated in Vietnam and suggest an alternative, non-invasive specimen collection strategy for early detection.

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Deletion of the L7L-L11L Genes Attenuates ASFV and Induces Protection against Homologous Challenge

Viruses ◽

10.3390/v13020255 ◽

2021 ◽

Vol 13 (2) ◽

pp. 255

Author(s):

Jingyuan Zhang ◽

Yanyan Zhang ◽

Teng Chen ◽

Jinjin Yang ◽

Huixian Yue ◽

...

Keyword(s):

African Swine Fever Virus ◽

Clinical Signs ◽

African Swine Fever ◽

Biological Properties ◽

High Dose ◽

Swine Industry ◽

Epidemic Disease ◽

Intramuscular Inoculation ◽

Homologous Challenge

African swine fever (ASF), caused by the African swine fever virus (ASFV), is a major epidemic disease endangering the swine industry. Although a number of vaccine candidates have been reported, none are commercially available yet. To explore the effect of unknown genes on the biological characteristics of ASFV and the possibility of a gene-deleted isolate as a vaccine candidate, the strain SY18ΔL7-11, with deletions of L7L–L11L genes from ASFV SY18, was constructed, and its biological properties were analyzed. The results show that deletion of genes L7L-L11L did not affect replication of the virus in vitro. Virulence of SY18△L7-11 was significantly reduced, as 11 of the 12 pigs survived for 28 days after intramuscular inoculation with a low dose (103 TCID50) or a high dose (106 TCID50) of SY18ΔL7-11. All 11 surviving pigs were completely protected against challenge with the parental ASFV SY18 on 28 days postinoculation (dpi). Transient fever and/or irregularly low levels of genomic DNA in the blood were monitored in some pigs after inoculation. No ASF clinical signs or viremia were monitored after challenge. Antibodies to ASFV were induced in all pigs from 14 to 21 days postinoculation. IFN-γ was detected in most of the inoculated pigs, which is usually inhibited in ASFV-infected pigs. Overall, the results demonstrate that SY18ΔL7-11 is a candidate for further constructing safer vaccine(s), with better joint deletions of other gene(s) related to virulence.

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Abstract P305: Post-Stroke Aphasia as a Predictor of 30-Day Readmission Associated With Infection: A Retrospective Chart Review

Stroke ◽

10.1161/str.52.suppl_1.p305 ◽

2021 ◽

Vol 52 (Suppl_1) ◽

Author(s):

Emma M Loebel ◽

Mary Rojas ◽

Connor Mensching ◽

Danielle Wheelwright ◽

Laura K Stein

Keyword(s):

Chart Review ◽

Retrospective Chart Review ◽

Mount Sinai Hospital ◽

Index Admission ◽

Negative Consequences ◽

Medical Comorbidities ◽

Post Stroke ◽

Increased Risk ◽

Adjusted Model ◽

The Impact

Introduction: Studies have demonstrated that aphasia may negatively impact morbidity and mortality among ischemic stroke (IS) patients. However, the association between post-stroke aphasia and readmission with infection (RI) is poorly understood. We sought to assess the impact of aphasia on post-stroke RI. We hypothesized that aphasic patients are at increased risk of infection in the 30-day post-stroke period. Methods: We performed retrospective chart review of the Mount Sinai Hospital IS patients with 30-day all cause readmission from January 2016 - December 2019. All variables were abstracted from the index admission (IA) electronic medical records except for aspects related to the readmission (RA). Aphasia was present if a neurologist diagnosed the patient with acquired language dysfunction during IA. We performed chi square and logistic regression analyses to compare readmitted patients with and without aphasia at IA. Our fully adjusted model controlled for age, sex, medical comorbidities, NIHSS ≥ 8, IA LOS > 7, IA infection, discharge to facility. We completed all analyses with SPSS. Results: During IA, 36% (n=42) were diagnosed with aphasia. At IA, there were no significant differences in age (dichotomized at 65), sex, or medical comorbidities between aphasic and non-aphasic cohorts. However, more aphasic patients had admission NIHSS ≥ 8 (89% vs 35%, p<0.0001), LOS > 7 (76% vs 42%, p=0.0004), discharge to facility (79% vs 49%, p=0.0016), and RI (52% vs 19%, p=0.002). The presence of aphasia predicted RI in both unadjusted (OR=4.6, p<0.001) and adjusted (OR= 3.3, p=0.014) multivariate analyses. The Kappa inter-reliability ranged from 0.7-1.0 for the key variables included in our adjusted model. Conclusions: The adjusted odds of 30-day readmission with infection were significantly greater in those with diagnosis of aphasia at the time of index admission compared to those without. Our study provides preliminary evidence that the presence of aphasia may have negative consequences on a patient’s health beyond the language disturbance. Further study is needed to better understand the reasons and risk reduction strategies in this vulnerable population.

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Role of African swine fever virus (ASFV) proteins EP153R and EP402R in reducing viral persistence and virulence from attenuated BeninΔDP148R

10.1101/2021.04.16.439957 ◽

2021 ◽

Author(s):

Vlad Petrovan ◽

Anusyah Rathakrishnan ◽

Muneeb Islam ◽

Lynnette Goatley ◽

Katy Moffat ◽

...

Keyword(s):

Virus Replication ◽

Vaccine Development ◽

African Swine Fever Virus ◽

Clinical Signs ◽

African Swine Fever ◽

Viral Persistence ◽

Fever Virus ◽

Post Immunization

The limited knowledge on the role of many of the approximately 170 proteins encoded by African swine fever virus restricts progress towards vaccine development. In this study we investigated the effect of deleting combinations of different genes from a previously attenuated virus, BeninΔDP148R on: virus replication in macrophages, virus persistence and clinical signs post immunization, and induction of protection against challenge. Deletion of either EP402R or EP153R genes individually or in combination from BeninΔDP148R did not reduce virus replication in vitro. However, deletion of EP402R dramatically reduced viral persistence in vivo, whilst maintaining high levels of protection against challenge. The additional deletion of EP153R (BeninΔDP148RΔEP153RΔEP402R) further attenuated the virus and no viremia or clinical signs were observed post immunization. This was associated with decreased protection and detection of moderate levels of challenge virus in blood. Interestingly, the deletion of EP153R alone from BeninΔDP148R did not result in further virus attenuation and a slight increase in virus genome copies in blood was observed at different times post immunization when compared with BeninΔDP148R. These results show that EP402R and EP153R have a synergistic role in promoting viremia, however EP153R alone does not seem to have a major impact on virus levels in blood.

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Estimation of the transmission dynamics of African swine fever virus within a swine house

Epidemiology and Infection ◽

10.1017/s0950268817001613 ◽

2017 ◽

Vol 145 (13) ◽

pp. 2787-2796 ◽

Cited By ~ 3

Author(s):

J. P. NIELSEN ◽

T. S. LARSEN ◽

T. HALASA ◽

L. E. CHRISTIANSEN

Keyword(s):

African Swine Fever Virus ◽

African Swine Fever ◽

Simulation Models ◽

Fever Virus ◽

Economic Consequences ◽

Estimation Of Parameters ◽

Swine Industry ◽

Transmission Parameters ◽

The Individual ◽

The Impact

SUMMARYThe spread of African swine fever virus (ASFV) threatens to reach further parts of Europe. In countries with a large swine production, an outbreak of ASF may result in devastating economic consequences for the swine industry. Simulation models can assist decision makers setting up contingency plans. This creates a need for estimation of parameters. This study presents a new analysis of a previously published study. A full likelihood framework is presented including the impact of model assumptions on the estimated transmission parameters. As animals were only tested every other day, an interpretation was introduced to cover the weighted infectiousness on unobserved days for the individual animals (WIU). Based on our model and the set of assumptions, the within- and between-pen transmission parameters were estimated to βw = 1·05 (95% CI 0·62–1·72), βb = 0·46 (95% CI 0·17–1·00), respectively, and the WIU = 1·00 (95% CI 0–1). Furthermore, we simulated the spread of ASFV within a pig house using a modified SEIR-model to establish the time from infection of one animal until ASFV is detected in the herd. Based on a chosen detection limit of 2·55% equivalent to 10 dead pigs out of 360, the disease would be detected 13–19 days after introduction.

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Lack of application of the European Work Time Directive: effects on workload, work satisfaction and burnout among Italian physicians

Italian Journal of Medicine ◽

10.4081/itjm.2017.714 ◽

2017 ◽

Vol 11 (2) ◽

pp. 159

Author(s):

Paola Gnerre ◽

Domenico Montemurro ◽

Andrea P. Rossi ◽

Costantino Troise ◽

Carlo Palermo ◽

...

Keyword(s):

Quality Of Life ◽

Work Conditions ◽

Public Hospitals ◽

Burnout Syndrome ◽

Negative Consequences ◽

Work Time ◽

Increased Risk ◽

Wide Range ◽

The Impact

The Italian Parliament has excluded hospital physicians from the application of the European Work Time Directive (EWTD), which imposes a maximum workweek of 48 h and compulsory resting periods. This resulted in extended and excessive work time for the category. This paper is aimed at evaluating the impact of this legislation gap, by assessing the presence of excessive work-related stress and risk for burnout syndrome among Italian physicians working in public hospitals. This observational study is based on an on-line survey conducted on a sample of 1925 Italian doctors (covering a wide range of age, work experience and contractual positions) from October 2014 to February 2015. The questionnaire included 30 questions concerning their personal and professional life (<em>e.g</em>., assessment of workloads, number of uncomfortable or extra shifts, unused days-off, <em>etc</em>.). On the basis of the results, it can be inferred that the average Italian doctor working in public hospitals is under considerable stress at work with negative consequences on his health. He is exposed to high risk of suffering from sleep disorders and cardiovascular diseases (due to the lack of time for private practice and eating regular meals). Overall, his perception is that his job worsens his quality of life. This study shows the relevance of the risk of burnout among Italian physicians employed in public hospitals due to severe workload and work conditions. The resulting impact on the quality of care and the significant cost involved - both in human and economic terms - calls for significant emergency measures by the Italian health work organization. An important increase and prolonged working time is associated with a worsening of the objective cognitive performance and an increase of clinical risk, but also to an increased risk of diseases for operators and of the burnout syndrome. Our survey shows that lack of application of the EWTD has adverse effects on the quality of life and performance of Italian doctors. Failure to respond by all Italian doctors is the greatest limitation of our survey.

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