Similarities and Differences Between Two Deadly Caribbean Coral Diseases: White Plague and Stony Coral Tissue Loss Disease

For several decades, white plagues (WPDs: WPD-I, II and III) and more recently, stony coral tissue loss disease (SCTLD) have significantly impacted Caribbean corals. These diseases are often difficult to separate in the field as they produce similar gross signs. Here we aimed to compare what we know about WPD and SCTLD in terms of: (1) pathology, (2) etiology, and (3) epizootiology. We reviewed over 114 peer-reviewed publications from 1973 to 2021. Overall, WPD and SCTLD resemble each other macroscopically, mainly due to the rapid tissue loss they produce in their hosts, however, SCTLD has a more concise case definition. Multiple-coalescent lesions are often observed in colonies with SCTLD and rarely in WPD. A unique diagnostic sign of SCTLD is the presence of bleached circular areas when SCTLD lesions are first appearing in the colony. The paucity of histopathologic archives for WPDs for multiple species across geographies makes it impossible to tell if WPD is the same as SCTLD. Both diseases alter the coral microbiome. WPD is controversially regarded as a bacterial infection and more recently a viral infection, whereas for SCTLD the etiology has not been identified, but the putative pathogen, likely to be a virus, has not been confirmed yet. Most striking differences between WPD and SCTLD have been related to duration and phases of epizootic events and mortality rates. While both diseases may become highly prevalent on reefs, SCTLD seems to be more persistent even throughout years. Both transmit directly (contact) and horizontally (waterborne), but organism-mediated transmission is only proven for WPD-II. Given the differences and similarities between these diseases, more detailed information is needed for a better comparison. Specifically, it is important to focus on: (1) tagging colonies to look at disease progression and tissue mortality rates, (2) tracking the fate of the epizootic event by looking at initial coral species affected, the features of lesions and how they spread over colonies and to a wider range of hosts, (3) persistence across years, and (4) repetitive sampling to look at changes in the microbiome as the disease progresses. Our review shows that WPDs and SCTLD are the major causes of coral tissue loss recorded in the Caribbean.

Microbial dysbiosis reflects disease resistance in diverse coral species

Disease outbreaks have caused significant declines of keystone coral species. While forecasting disease outbreaks based on environmental factors has progressed, we still lack a comparative understanding of susceptibility among coral species that would help predict disease impacts on coral communities. The present study compared the phenotypic and microbial responses of seven Caribbean coral species with diverse life-history strategies after exposure to white plague disease. Disease incidence and lesion progression rates were evaluated over a seven-day exposure. Coral microbiomes were sampled after lesion appearance or at the end of the experiment if no disease signs appeared. A spectrum of disease susceptibility was observed among the coral species that corresponded to microbial dysbiosis. This dysbiosis promotes greater disease susceptiblity in coral perhaps through different tolerant thresholds for change in the microbiome. The different disease susceptibility can affect coral’s ecological function and ultimately shape reef ecosystems.

Tracking down the White Plague. Chapter three: Revision of endocranial abnormally pronounced digital impressions as paleopathological diagnostic criteria for tuberculous meningitis

Abnormally pronounced digital impressions (APDIs) on the endocranial surface develop secondary to a prolonged rise in the intracranial pressure. This can result from a number of pathological conditions, including hydrocephalus due to tuberculous meningitis (TBM). APDIs have been described with relation to TBM not only in the modern medical literature but also in several paleopathological studies. However, APDIs are not pathognomonic for TBM and their diagnostic value for identifying TBM in past human populations has not been evaluated in identified pre-antibiotic era skeletons. To assess the diagnostic value of APDIs for the first time, a macroscopic investigation was performed on skeletons from the Terry Collection (Smithsonian Institution, Washington, DC, USA). Our material consisted of 234 skeletons with tuberculosis (TB) as the cause of death (TB group) and 193 skeletons with non-tuberculous (NTB) causes of death (NTB group). The macroscopic examination focused on the stage of the prominence and frequency of APDIs in the TB group and NTB group. To determine the significance of difference (if any) in the frequency of APDIs between the two groups, χ2 testing of our data was conducted. We found that APDIs were twice as common in the TB group than in the NTB group. The χ2 comparison of the frequencies of APDIs revealed a statistically significant difference between the two groups. In addition, APDIs with more pronounced stages were recorded more frequently in the TB group. Our results indicate that APDIs can be considered as diagnostic criteria for TBM in the paleopathological practice. With suitable circumspection, their utilization provides paleopathologists with a stronger basis for identifying TB and consequently, with a more sensitive means of assessing TB frequency in past human populations.

Histopatological effects of bleaching and disease on the coral Siderastrea stellata from coastal reefs of Brazil

ABSTRACT Histological analysis of bleached samples of Siderastrea stellata Verrill, 1868, with white plague disease and with alteration in the color pattern, revealed drastic tissue and cellular disturbances, such as lysis of the external epithelium, hyperplasia of gastrodermis, apoptosis of epithelial cells and zooxanthellae, and degradation of mesenteric filaments and reproductive cells. Fungal hyphae, diatoms, and cyanobacteria were present in diseased samples and colonies with alteration in the color pattern. Furthermore, bleached and diseased samples showed significant reductions in the number of zooxanthellae per 100 µm2 of gastrodermis and significant reductions in the diameters and volumes of stage V oocytes. We found that bleaching events, diseases, and colonies with alteration in the color pattern promoted degradation of reproductive cells, resulting in the consequent interruption of the reproduction of the coral S. stellata, which is one of the most common Brazilian coral species. The implications of these indirect effects of bleaching, disease, and changes in coral color patterns in the population dynamics of Brazilian reefs are discussed.

LAJU INFEKSI PENYAKIT WHITE PLAGUE DAN WHITE BAND DISEASE DI PERAIRAN PULAU TIKUS, KOTA BENGKULU

Penyakit karang adalah gangguan terhadap kesehatan karang yang menyebabkan gangguan secara fisiologis bagi biota karang. Penyakit karang dapat memberikan dampak buruk terhadap proses pertumbuhan karang hingga dapat menyebabkan kematian karang disuatu perairan. Dampak dari penyakit karang terhadap ekosistem terumbu karang sangat besar, selain mengakibatkan kematian karang dalam skala yang luas, penyakit karang juga berdampak pada berkurangnya tingkat keanekaragaman sumberdaya alam. Penelitian ini bertujuan untuk mengetahui dan menganalisis laju infeksi penyakit White Plague dan White Band Disease di perairan Pulau Tikus, Kota Bengkulu. Penelitian ini dilaksanakan pada bulan September-Oktober 2019 di Perairan Pulau Tikus, Kota Bengkulu. Metode yang digunakan dalam penelitian ini adalah metode survei, pengamatan dan pengukuran langsung di Lapangan. Hasil Penelitian ini didapatkan bentuk pertumbuhan yang terinfeksi penyakit White Plague di Perairan Pulau Tikus Kota Bengkulu adalah bentuk pertumbuhan karang Massive dan penyakit White Band Disease pada karang Acropora. Metode yang digunakan dalam penelitian ini adalah metode survei, pengamatan dan pengukuran langsung di lapangan.Laju infeksi penyakit White Plague di perairan Pulau Tikus Kota Bengkulu adalah 0,009 - 0,023 cm/hari. Laju infeksi penyakit White Plague mengalami kenaikan setiap minggu dengan rata rata laju infeksi 0,015 cm/hari dan nilai laju infeksi penyakit White Band Disease yang terdapat pada karang Acropora di Perairan Pulau Tikus, Bengkulu yaitu 0,013 cm/hari – 0,030 cm/hari. Rata – rata yang diperoleh yaitu 0,024 cm/hari. Nilai laju infeksi karang menandakan bahwa sebagian besar kerusakan terumbu karang diakibatkan oleh penyakit karang.THE RATE OF WHITE PLAGUE AND WHITE BAND DISEASE IN TIKUS ISLAND, BENGKULU CITY. Coral disease is a disorder of coral health that causes physiological disruption to coral biota. The coral disease can adversely affect the coral growth process until it can lead to coral death in a waterway. The impact of coral disease on coral ecosystems is very large. In addition to resulting in coral death on a wide scale, a coral disease also affects natural resources' reduced diversity. This research aimed to determine and analyze the White Plague and White Band Disease's infection rate in Tikus Island, Bengkulu City. The research was conducted in September-October 2019, located in Tikus Island Water, Bengkulu City. The methods used in this study are direct survey, observation, and measurement methods in the Field. This study obtained a form of growth infected with White Plague disease in the Waters of Tikus Island Bengkulu City. The infection rate of White Plague Disease in Tikus Island was 0.009-0.023 cm/day. The quality of the condition of White Plague disease increased every week with an average infection rate of 0.015 cm/day, and the rate of infection rate of White Band Disease found in Acropora coral in the Waters of Tikus Island, Bengkulu which was 0.013 cm/day – 0.030 cm/day. The average obtained 0.024 cm/day. The coral infection rate indicates that most of the damage to coral reefs was caused by coral disease.

PREVALENSI DAN JENIS PENYAKIT YANG MENGINFEKSI KARANG DI PERAIRAN PULAU ENGGANO BENGKULU

Penyakit karang merupakan salah satu permasalahan ekosistem terumbu karang yang diakibatkan oleh manusia. Penyakit karang dapat menyebabkan penurunan kualitas dan daya imun karang yang ditandai dengan terhambatnya laju pertumbuhan pada karang dan berdampak pada matinya karang di suatu perairan. Penelitian ini bertujuan untuk mengidentifikasi jenis penyakit dan bentuk pertumbuhan karang yang sering terinfeksi penyakit serta menganalisis prevalensi penyakit karang di Perairan Pulau Enggano, Bengkulu. Penelitian ini menggunakan metode survei. Pengambilan data penyakit karang dengan metode transek sabuk (Belt Transect). Hasil penelitian didapatkn 9 jenis penyakit yang ditemukan di Pulau Enggano, yaitu Yellow Band Desease, Black Band Desease, White Band Desease, Red Band Desease, Dark Plague, White Plague, Pink Plotch, dan Ulcerative White Spots, serta White Spot. Sedangkan bentuk pertumbuhan (lifeform) karang yang terinfeksi adalah Coral Massive dan Acropora Branching. Tingkat prevelensi karang tertinggi terdapat pada lokasi Kahabi, sedangkan terendah pada Pulau Dua di bagian windward. Tingginya tingkat prevalensi di Kahabi dimungkinkan karena tingginya kedalaman di lokasi tersebut. Rendahnya tingkat prevalensi karang pada Pulau Dua di sisi windward dimungkinkan karena pada sisi ini merupakan daerah yang terkena arus tiap saat, sehingga membantu karang dalam membersihkan sedimen yang menempel pada permukaan yang dimungkinkan membawa bakteri penyebab penyakit karang.CORAL DISEASE PREVALENCE IN ENGGANO ISLAND, BENGKULU. Coral disease is one of the coral reef ecosystem problems caused by humans. Coral disease causes a decrease in the quality and immunity of corals characterized by stunted growth rates on corals and impacts on the death of corals in waters. This study aims to identify the types of coral disease and coral lifeform that are often infected and analyze the prevalence of coral disease in Enggano Island Waters, Bengkulu. This research used survey method. Coral disease data were obtained using the belt transect method. The results obtained 9 types of coral diseases found on Enggano Island, namely Yellow Band Desease, Black Band Desease, White Band Desease, Red Band Desease, Dark Plague, White Plague, Pink Plotch, and Ulcerative White Spots, and White Spot. While infected lifeforms were Coral Massive and Acropora Branching. The highest level of coral prevalence was at the Kahabi site, while the lowest was on Pulau Dua in the windward area. The high prevalence rate in Kahabi might be due to the high depth at the location. The low level of coral prevalence on Pulau Dua on the windward side might be caused by being exposed to the current at any time, thus helping the coral in cleaning sediments attached to the surface which could carry the bacteria that cause coral disease.