scholarly journals Coral disease prevalence estimation and sampling design

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6006 ◽  
Author(s):  
Eric Jordán-Dahlgren ◽  
Adán G. Jordán-Garza ◽  
Rosa E. Rodríguez-Martínez
Keyword(s):  
Disease Transmission ◽  
Coral Disease ◽  
Disease Prevalence ◽  
Statistical Confidence ◽  
Coral Colony ◽  
Transmission Modes ◽  
Sampling Protocols ◽  
Prevalence Estimates ◽  
Coral Communities ◽  
And Function

In the last decades diseases have changed coral communities’ structure and function in reefs worldwide. Studies conducted to evaluate the effect of diseases on corals frequently use modified adaptations of sampling designs that were developed to study ecological aspects of coral reefs. Here we evaluate how efficient these sampling protocols are by generating virtual data for a coral population parameterized with mean coral density and disease prevalence estimates from the Caribbean scleractinian Orbicella faveolata at the Mexican Caribbean. Six scenarios were tested consisting of three patterns of coral colony distribution (random, randomly clustered and randomly over-dispersed) and two disease transmission modes (random and contagious). The virtual populations were sampled with the commonly used method of belt-transects with variable sample-unit sizes (10 × 1, 10 × 2, 25 × 2, 50 × 2 m). Results showed that the probability of obtaining a mean coral disease prevalence estimate of ±5% of the true prevalence value was low (range: 11–48%) and that two-sample comparisons achieved rather low power, unless very large effect sizes existed. Such results imply low statistical confidence to assess differences or changes in coral disease prevalence. The main problem identified was insufficient sample size because local mean colony size, density and spatial distribution of targeted coral species was not taken into consideration to properly adjust the sampling protocols.

scholarly journals A rapid spread of the Stony Coral Tissue Loss Disease outbreak in the Mexican Caribbean

2019 ◽  
Author(s):  
Lorenzo Alvarez-Filip ◽  
Nuria Estrada-Saldívar ◽  
Esmeralda Pérez-Cervantes ◽  
Ana Molina-Hernández ◽  
Francisco J. Gonzalez-Barrios
Keyword(s):  
Coral Disease ◽  
Disease Outbreak ◽  
Disease Prevalence ◽  
Tissue Loss ◽  
Coral Tissue ◽  
Similar Species ◽  
Western Atlantic ◽  
Stony Coral ◽  
Mexican Caribbean ◽  
Coral Communities

Caribbean reef corals have experienced unprecedented declines from climate change, anthropogenic stressors and infectious diseases in recent decades. Since 2014 a highly lethal, new disease, called stony coral tissue loss disease (SCTLD), has impacted many species in Florida. During the summer of 2018 we noticed an anomalously high disease prevalence affecting different coral species in the northern portion of the Mexican Caribbean. We assessed the severity of this outbreak in 2018/2019 using the AGRRA coral protocol to survey 82 reef sites across the Mexican Caribbean. Then, using a subset of 14 sites we detailed information from before the outbreak (2016/2017) to explore the consequences of the disease on the condition and composition of coral communities. Our findings show that the disease outbreak has already spread across the entire region, affecting similar species (with similar disease patterns) to those previously described for Florida. However, we observed a great variability in prevalence and tissue mortality that was not attributable to any geographical gradient. Using long-term data, we determined that there is no evidence of such high coral disease prevalence anywhere in the region before 2018, which suggests that the entire Mexican Caribbean (~450 km) was afflicted by the disease within a few months. The analysis of sites that contained pre-outbreak information showed that this event considerably increased coral mortality and severely changed the structure of coral communities in the region. Given the high prevalence and lethality of this disease, and the high number of susceptible species, we encourage reef researchers, managers and stakeholders across the Western Atlantic to accord it the highest priority for the near future.

scholarly journals Characterization of the Coral Disease 'Porites Bleaching with Tissue Loss' (PBTL) From Hawaii

2021 ◽  
Author(s):  
◽  
Mareike Sudek
Keyword(s):  
Coral Reefs ◽  
Coral Disease ◽  
Seawater Temperature ◽  
Temporal Variations ◽  
Disease Prevalence ◽  
Tissue Loss ◽  
Disease Dynamics ◽  
Kaneohe Bay ◽  
Coral Colony ◽  
Bleaching Response

<p>Coral reefs around the world are facing many threats and have sustained severe losses in coral cover over the past few decades. Coral bleaching and disease outbreaks have contributed substantially to this reef decline, however our understanding of factors contributing to the increase in coral disease prevalence are poorly understood. Information on the disease dynamics of different diseases affecting a reef system is essential for the development of effective management strategies.  The aim of this research was to characterise and build a case study of a bleaching response affecting Porites compressa in Kaneohoe Bay, Oahu, Hawaii. It manifests as a localised, discrete area on the coral colony with a bleached coenenchyme and pigmented polyps, giving the affected area a “speckled” appearance. A disease by definition is any interruption, cessation or disorder of body functions, systems or organs. Results of this study showed that this localised bleaching causes tissue loss and a reduction in the number of gametes, and hence harm to the host. It was therefore classified as a disease and named Porites bleaching with tissue loss (PBTL). In addition, PBTL does not appear to represent a common thermal bleaching response as it was present throughout the year during times when seawater temperature was well within the coral’s thermal threshold.  Symbiodinium cell density in PBTL-affected areas of the coral colony was reduced by 65%, and examination of affected host tissue using light microscopy showed fragmentation and necrosis. However, no potential pathogen was observed. Transmission electron microscopy (TEM) revealed a high occurrence of potential apoptotic Symbiodinium cells and a potential increase in the abundance of virus-like particles (VLPs) in PBTL-affected tissue. However a causal relationship remains to be established. Long-term monitoring showed spatio-temporal variations in PBTL prevalence. Temporal variations in prevalence reflected a seasonal trend with a peak during the summer months, linked to increasing seawater temperature. Spatial variations in disease prevalence were correlated with parrotfish density, turbidity and water motion. Of these, a negative correlation with variability (SD) in turbidity explained most of the variability in PBTL prevalence (12.8%). A positive correlation with water motion explained 9% and a positive correlation with the variability in parrotfish density explained 4.4%. Overall, only a relatively small proportion of variability in PBTL prevalence could be explained by these three factors (26.2%), suggesting that other factors, not investigated in this study, play a more important role in explaining PBTL patterns or that temporal variation in temperature is the overall major driving force.  Monitoring of individually tagged P. compressa colonies showed that >80% of affected colonies sustained partial colony mortality (tissue loss) within two months; on average, one third of the colony is lost. The amount of tissue loss sustained was correlated to lesion size but not colony size. Case fatality (total mortality) was low (2.6%), however this disease can affect the same colonies repeatedly, suggesting a potential for progressive damage which could cause increased tissue loss over time. PBTL was not transmissible through direct contact or the water column in controlled aquaria experiments, suggesting that this disease might not be caused by a pathogen, is not highly infectious, or perhaps requires a vector for transmission. At present, PBTL has only been observed within Kaneohe Bay. An investigation of the potential role of host and Symbiodinium genetics in disease susceptibility revealed the same Symbiodinium sub-clade (C15) in healthy and PBTL-affected colonies, suggesting no involvement of Symbiodinium type in disease etiology. Results regarding host genetics remained inconclusive; however a difference in allele frequency at one microsatellite locus was observed between healthy and diseased samples. This difference could, however, be due to a lower amplification of PBTL-affected samples at this locus and needs to be regarded with some caution.  The results of this study provide a case definition of PBTL which can be used as a baseline in further studies. P. compressa is the main framework building species in Kaneohe Bay, and the information gathered here on disease dynamics and virulence suggests that PBTL has the potential to negatively impact the resilience of reefs within the bay. Further research into the etiology of PBTL is necessary to fully understand the impact that this disease could have on coral reefs in Hawaii.</p>

scholarly journals A rapid spread of the Stony Coral Tissue Loss Disease outbreak in the Mexican Caribbean

2019 ◽  
Author(s):  
Lorenzo Alvarez-Filip ◽  
Nuria Estrada-Saldívar ◽  
Esmeralda Pérez-Cervantes ◽  
Ana Molina-Hernández ◽  
Francisco J. Gonzalez-Barrios
Keyword(s):  
Coral Disease ◽  
Disease Outbreak ◽  
Disease Prevalence ◽  
Tissue Loss ◽  
Coral Tissue ◽  
Similar Species ◽  
Western Atlantic ◽  
Stony Coral ◽  
Mexican Caribbean ◽  
Coral Communities

Caribbean reef corals have experienced unprecedented declines from climate change, anthropogenic stressors and infectious diseases in recent decades. Since 2014 a highly lethal, new disease, called stony coral tissue loss disease (SCTLD), has impacted many species in Florida. During the summer of 2018 we noticed an anomalously high disease prevalence affecting different coral species in the northern portion of the Mexican Caribbean. We assessed the severity of this outbreak in 2018/2019 using the AGRRA coral protocol to survey 82 reef sites across the Mexican Caribbean. Then, using a subset of 14 sites we detailed information from before the outbreak (2016/2017) to explore the consequences of the disease on the condition and composition of coral communities. Our findings show that the disease outbreak has already spread across the entire region, affecting similar species (with similar disease patterns) to those previously described for Florida. However, we observed a great variability in prevalence and tissue mortality that was not attributable to any geographical gradient. Using long-term data, we determined that there is no evidence of such high coral disease prevalence anywhere in the region before 2018, which suggests that the entire Mexican Caribbean (~450 km) was afflicted by the disease within a few months. The analysis of sites that contained pre-outbreak information showed that this event considerably increased coral mortality and severely changed the structure of coral communities in the region. Given the high prevalence and lethality of this disease, and the high number of susceptible species, we encourage reef researchers, managers and stakeholders across the Western Atlantic to accord it the highest priority for the near future.

scholarly journals Characterization of the Coral Disease 'Porites Bleaching with Tissue Loss' (PBTL) From Hawaii

2021 ◽  
Author(s):  
◽  
Mareike Sudek
Keyword(s):  
Coral Reefs ◽  
Coral Disease ◽  
Seawater Temperature ◽  
Temporal Variations ◽  
Disease Prevalence ◽  
Tissue Loss ◽  
Disease Dynamics ◽  
Kaneohe Bay ◽  
Coral Colony ◽  
Bleaching Response

<p>Coral reefs around the world are facing many threats and have sustained severe losses in coral cover over the past few decades. Coral bleaching and disease outbreaks have contributed substantially to this reef decline, however our understanding of factors contributing to the increase in coral disease prevalence are poorly understood. Information on the disease dynamics of different diseases affecting a reef system is essential for the development of effective management strategies.  The aim of this research was to characterise and build a case study of a bleaching response affecting Porites compressa in Kaneohoe Bay, Oahu, Hawaii. It manifests as a localised, discrete area on the coral colony with a bleached coenenchyme and pigmented polyps, giving the affected area a “speckled” appearance. A disease by definition is any interruption, cessation or disorder of body functions, systems or organs. Results of this study showed that this localised bleaching causes tissue loss and a reduction in the number of gametes, and hence harm to the host. It was therefore classified as a disease and named Porites bleaching with tissue loss (PBTL). In addition, PBTL does not appear to represent a common thermal bleaching response as it was present throughout the year during times when seawater temperature was well within the coral’s thermal threshold.  Symbiodinium cell density in PBTL-affected areas of the coral colony was reduced by 65%, and examination of affected host tissue using light microscopy showed fragmentation and necrosis. However, no potential pathogen was observed. Transmission electron microscopy (TEM) revealed a high occurrence of potential apoptotic Symbiodinium cells and a potential increase in the abundance of virus-like particles (VLPs) in PBTL-affected tissue. However a causal relationship remains to be established. Long-term monitoring showed spatio-temporal variations in PBTL prevalence. Temporal variations in prevalence reflected a seasonal trend with a peak during the summer months, linked to increasing seawater temperature. Spatial variations in disease prevalence were correlated with parrotfish density, turbidity and water motion. Of these, a negative correlation with variability (SD) in turbidity explained most of the variability in PBTL prevalence (12.8%). A positive correlation with water motion explained 9% and a positive correlation with the variability in parrotfish density explained 4.4%. Overall, only a relatively small proportion of variability in PBTL prevalence could be explained by these three factors (26.2%), suggesting that other factors, not investigated in this study, play a more important role in explaining PBTL patterns or that temporal variation in temperature is the overall major driving force.  Monitoring of individually tagged P. compressa colonies showed that >80% of affected colonies sustained partial colony mortality (tissue loss) within two months; on average, one third of the colony is lost. The amount of tissue loss sustained was correlated to lesion size but not colony size. Case fatality (total mortality) was low (2.6%), however this disease can affect the same colonies repeatedly, suggesting a potential for progressive damage which could cause increased tissue loss over time. PBTL was not transmissible through direct contact or the water column in controlled aquaria experiments, suggesting that this disease might not be caused by a pathogen, is not highly infectious, or perhaps requires a vector for transmission. At present, PBTL has only been observed within Kaneohe Bay. An investigation of the potential role of host and Symbiodinium genetics in disease susceptibility revealed the same Symbiodinium sub-clade (C15) in healthy and PBTL-affected colonies, suggesting no involvement of Symbiodinium type in disease etiology. Results regarding host genetics remained inconclusive; however a difference in allele frequency at one microsatellite locus was observed between healthy and diseased samples. This difference could, however, be due to a lower amplification of PBTL-affected samples at this locus and needs to be regarded with some caution.  The results of this study provide a case definition of PBTL which can be used as a baseline in further studies. P. compressa is the main framework building species in Kaneohe Bay, and the information gathered here on disease dynamics and virulence suggests that PBTL has the potential to negatively impact the resilience of reefs within the bay. Further research into the etiology of PBTL is necessary to fully understand the impact that this disease could have on coral reefs in Hawaii.</p>

The association between coral communities and disease assemblages in the Wakatobi Marine National Park, south-eastern Sulawesi, Indonesia

2015 ◽  
Vol 66 (10) ◽  
pp. 948 ◽  
Author(s):  
J. Haapkylä ◽  
J. Melbourne-Thomas ◽  
M. Flavell
Keyword(s):  
Community Structure ◽  
National Park ◽  
Coral Cover ◽  
Coral Disease ◽  
Monitoring Program ◽  
Disease Outbreaks ◽  
Coral Community ◽  
Disease Prevalence ◽  
Dramatic Decline ◽  
Coral Communities

The relationship between coral community structure and disease prevalence is poorly understood, particularly in the Coral Triangle. Improved understanding of this relationship will assist in identifying assemblages that might be particularly vulnerable to disease, and in predicting possible future impacts. Here, we report results from the last 2 years (2010 and 2011) of a 4-year coral disease-monitoring program (2005, 2007, 2010, 2011) in the Wakatobi Marine National Park (Indonesia), and evaluate changes in total disease prevalence and coral cover since 2005. A comparison with previously published results from 2005 and 2007 indicates that the number of coral diseases increased from two to eight and total disease prevalence tripled between 2005 and 2011. We observed a dramatic decline in coral cover and an increase in disease prevalence at a site with a unique community of foliose corals. However, because of the 3-year period between surveys (2007, 2010), it is likely that the peak of the disease event was not observed. While multi-year studies provide useful insights into the relationships between community structure and disease, our results emphasise how determining the drivers of change in remote reef locations is especially challenging if events such as disease outbreaks are missed.

scholarly journals Mapping chronic disease prevalence based on medication use and socio-demographic variables: an application of LASSO on administrative data sources in healthcare in the Netherlands

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Koen Füssenich ◽  
Hendriek C. Boshuizen ◽  
Markus M. J. Nielen ◽  
Erik Buskens ◽  
Talitha L. Feenstra
Keyword(s):  
Chronic Disease ◽  
Hospital Admission ◽  
Medication Use ◽  
Disease Prevalence ◽  
Percentage Error ◽  
Economic Variables ◽  
Regional Patterns ◽  
Prevalence Estimates ◽  
Socio Economic Variables ◽  
Chronic Disease Prevalence

Abstract Background Policymakers generally lack sufficiently detailed health information to develop localized health policy plans. Chronic disease prevalence mapping is difficult as accurate direct sources are often lacking. Improvement is possible by adding extra information such as medication use and demographic information to identify disease. The aim of the current study was to obtain small geographic area prevalence estimates for four common chronic diseases by modelling based on medication use and socio-economic variables and next to investigate regional patterns of disease. Methods Administrative hospital records and general practitioner registry data were linked to medication use and socio-economic characteristics. The training set (n = 707,021) contained GP diagnosis and/or hospital admission diagnosis as the standard for disease prevalence. For the entire Dutch population (n = 16,777,888), all information except GP diagnosis and hospital admission was available. LASSO regression models for binary outcomes were used to select variables strongly associated with disease. Dutch municipality (non-)standardized prevalence estimates for stroke, CHD, COPD and diabetes were then based on averages of predicted probabilities for each individual inhabitant. Results Adding medication use data as a predictor substantially improved model performance. Estimates at the municipality level performed best for diabetes with a weighted percentage error (WPE) of 6.8%, and worst for COPD (WPE 14.5%)Disease prevalence showed clear regional patterns, also after standardization for age. Conclusion Adding medication use as an indicator of disease prevalence next to socio-economic variables substantially improved estimates at the municipality level. The resulting individual disease probabilities could be aggregated into any desired regional level and provide a useful tool to identify regional patterns and inform local policy.

scholarly journals Contribution of Terrestrial Runoff to Coral Disease Prevalence on North Bali’s Massive Porites

2017 ◽  
Vol 22 (4) ◽  
pp. 193
Author(s):  
I Gusti Bagus Siladharma ◽  
Widiastuti Karim
Keyword(s):  
Organic Carbon ◽  
Coral Disease ◽  
Environmental Parameters ◽  
Strong Relationship ◽  
Disease Prevalence ◽  
Terrestrial Runoff ◽  
Dominant Disease ◽  
Massive Porites ◽  
High Level ◽  
Organic Carbon Loading

The widespread of coral disease may threatened Bali`s marine tourism which is the main asset for the nation prosperity. However, the disease prevalence is still unknown, in particular inshore coral reefs near to tourist spot areas. Therefore, the research aims to investigate the contribution of terrestrial runoff to coral disease prevalence and to examine the relationships between disease prevalence and environmental parameters (nitrate, phosphate, organic carbon and total suspended solids (TSS)) within the population of massive Porites on shallow north Bali reefs. Syndrome, diseases and healthy colonies of massive Porites coral were counted and noted within a 2 x 10 m belt transect at 3 sampling sites. The dominant disease observed was ulcerative white spots (UWS), while the syndromes were pigmentation response and aggressive overgrowth by macroalgae. The highest mean UWS prevalence was at site 3 which was the closest site to runoff (prevalence = 91%).This disease only affected one colony at site 1 and 2, respectively. Disease prevalence had strong relationship with TSS and nitrate, yet it showed weak relationship with phosphate and organic carbon. These results suggest that terrestrial runoff could contribute to the disease prevalence by increasing the TSS, nutrients and organic carbon loading to the inshore ecosystems. High level of organic carbon could severe the disease, particularly when combined with elevated TSS and nutrient, by reducing the coral`s immunity system. Keywords: coral disease, prevalence, terrestrial runoff, Porites, ulcerative white spot, environmental parameter, North Bali.

scholarly journals Disease transmission by cannibalism: rare event or common occurrence?

2007 ◽  
Vol 274 (1614) ◽  
pp. 1205-1210 ◽  
Author(s):  
Volker H.W Rudolf ◽  
Janis Antonovics
Keyword(s):  
Disease Transmission ◽  
Rare Event ◽  
Disease Spread ◽  
Necessary Condition ◽  
Transmission Route ◽  
Review Of The Literature ◽  
Common Occurrence ◽  
Endemic Diseases ◽  
Pathogen Dynamics ◽  
Transmission Modes

Cannibalism has been documented as a possible disease transmission route in several species, including humans. However, the dynamics resulting from this type of disease transmission are not well understood. Using a theoretical model, we explore how cannibalism (i.e. killing and consumption of dead conspecifics) and intraspecific necrophagy (i.e. consumption of dead conspecifics) affect host–pathogen dynamics. We show that group cannibalism, i.e. shared consumption of victims, is a necessary condition for disease spread by cannibalism in the absence of alternative transmission modes. Thus, endemic diseases transmitted predominantly by cannibalism are likely to be rare, except in social organisms that share conspecific prey. These results are consistent with a review of the literature showing that diseases transmitted by cannibalism are infrequent in animals, even though both cannibalism and trophic transmission are very common.

Sign in / Sign up

Export Citation Format

Share Document