scholarly journals First Report of Virulence in Puccinia graminis f. sp. tritici to Wheat Stem Rust Resistance Genes Sr8b and Sr38 in South Africa

Plant Disease ◽  
2002 ◽  
Vol 86 (8) ◽  
pp. 922-922 ◽  
Author(s):  
W. H. P. Boshoff ◽  
Z. A. Pretorius ◽  
B. D. van Niekerk ◽  
J. S. Komen

During the 2000 to 2001 season, 27 stem rust samples were collected from wheat (Triticum aestivum), barley (Hordeum vulgare), and triticale (× Triticosecale) cultivars and lines in the Western Cape, South Africa. Following inoculation and multiplication on McNair 701 seedlings, 40 single pustule isolates of P. graminis f. sp. tritici were established. Twenty-six isolates obtained from wheat, barley, or triticale that produced a similar reaction pattern on a set of differentiating host lines, were designated as pathotype Pgt-2SA55. Pgt-2SA55 is avirulent to Sr5, -6, -7b, -8b, -9b, -9e, -9g, -23, -24, -27, -30, -38, and -Gt, and virulent to Sr11, and -Agi. The remaining 14 isolates, all from wheat and designated as pathotype Pgt-2SA88, were avirulent to Sr24, -27, and -Agi, and virulent to Sr5, -6, -7b, -8b, -9b, -9e, -9g, -11, -23, -30, -38, and -Gt. On an expanded differential set, representative isolates of each pathotype were all avirulent to Sr13, -15, -21, -22, -25, -26, -29, -31, -32, -33, -35, -39, -43, and -Em, and virulent to Sr7a, -8a, -9a, -9d, -9f, -10, -12, -14, -16, -19, -20, -34, and Lc. Pgt-2SA55 was avirulent on cv. Renown (Sr2, -7b, -9d, and -17), whereas Pgt-2SA88 was virulent on this cultivar and Line R Sel carrying only Sr17. Both pathotypes differ from those identified previously in South Africa (1) and to our knowledge, Pgt-2SA88 is the first local isolate to have virulence towards Sr8b and the T. ventricosum-derived gene Sr38. Virulence to Sr38 has been reported in a P. graminis f. sp. tritici isolate collected in Uganda (2). Pathotype Pgt-2SA88 is virulent to seedlings of the previously resistant South African cvs. SST 57 (heterogeneous), Tugela, Tugela DN, and PAN 3377. Furthermore, 20% of the elite breeding lines in the spring and winter wheat breeding program of the Small Grain Institute expressed susceptible seedling reactions to Pgt-2SA88. Triticale cvs. Rex and Kiewiet were heterogeneous in their seedling reaction towards Pgt-2SA55. Seedling and field reactions recorded for the barley cvs. Sterling and SSG 532 and the experimental varieties Puma and Jaguar, showed an increase in stem rust susceptibility to Pgt-2SA55 when compared with existing South African pathotypes. The higher incidence of stem rust in commercial fields and experimental plots of wheat and barley in the Western Cape may be attributed to a recent increase in the cultivation of stem rust-susceptible cultivars in the region. The detection of two new pathotypes of P. graminis f. sp. tritici is of concern to the local small grain industry and requires continued resistance breeding. References: (1) W. H. P. Boshoff et al. S. Afr. J Plant Soil 17:60, 2000. (2) Z. A. Pretorius et al. Plant Dis. 84:203, 2000.

Plant Disease ◽  
2012 ◽  
Vol 96 (4) ◽  
pp. 590-590 ◽  
Author(s):  
Z. A. Pretorius ◽  
L. J. Szabo ◽  
W. H. P. Boshoff ◽  
L. Herselman ◽  
B. Visser

Seven races have been described in the Ug99 race group of Puccinia graminis f. sp. tritici (2). Ug99-related races previously recorded in South Africa are TTKSF, TTKSP, and PTKST (4). In December 2010, severe stem rust infection of the winter wheat cv. Matlabas was observed for the first time in South Africa. Race analysis using the 20 North American (NA) stem rust differential lines and letter code system classified the race as TTKSF. In comparative infection studies in a greenhouse, cv. Matlabas seedlings were susceptible (infection type [IT] 4) to isolate UVPgt61/1 (TTKSF+) collected from Afrikaskop in the eastern Free State, whereas the cultivar was resistant (IT 1 to 2) to stem rust isolates 2013 (TTKSF), UVPgt55 (TTKSF), UVPgt59 (TTKSP), and UVPgt60 (PTKST). Isolate 2013 represents the original collection of race TTKSF in South Africa (1). In addition to the NA differentials, no variation in the IT range of seedlings of lines with Sr7a, 8b, 12, 13, 14, 16, 18, 19, 22, 25, 26, 27, 28, 29, 32, 33, 34, 35, 39, 41, 42, 43, 44, Em, R, Tt2, and Satu was observed between UVPgt61/1 and UVPgt55. With the exception of cv. Matlabas, ITs of 106 South African cultivars likewise did not differentiate UVPgt61/1 and UVPgt55. Seedling IT studies were conducted at least twice. Microsatellite analysis (4) showed that all single pustule isolates established from the original Matlabas isolate formed part of the Ug99 group. When characterized with selected single nucleotide polymorphisms (SNPs), all single pustule isolates shared an identical genotype that differed from UVPgt55 (TTKSF), a foreign introduction into South Africa (1,3). SNP genotype analysis suggests that UVPgt61/1 is genetically dissimilar to UVPgt55, as is Zim1009, another TTKSF+ isolate that was collected from Birchenough in Zimbabwe. Studies are underway to determine the identity of the defeated Sr gene in Matlabas and the cultivar has been added to the South African stem rust differential set. TTKSF+ is the eighth race detected in the Ug99 group. Since no other cultivars or advanced lines were found to carry the Matlabas gene, it is unlikely that race TTKSF+ will threaten wheat production in South Africa. However, the occurrence of a new Ug99-related race emphasizes the variability within this internationally important group. References: (1) W. H. P. Boshoff et al. Plant Dis. 86:922, 2002. (2) R. F. Park et al. Euphytica 179:109, 2011. (3) B. Visser et al. Mol. Plant Pathol. 10:213, 2009. (4) B. Visser et al. Euphytica 179:119, 2011.


2016 ◽  
Vol 106 (11) ◽  
pp. 1352-1358 ◽  
Author(s):  
Jayaveeramuthu Nirmala ◽  
Shiaoman Chao ◽  
Pablo Olivera ◽  
Ebrahiem M. Babiker ◽  
Bekele Abeyo ◽  
...  

Wheat stem rust, caused by Puccinia graminis f. sp. tritici, can cause severe yield losses on susceptible wheat varieties and cultivars. Although stem rust can be controlled by the use of genetic resistance, population dynamics of P. graminis f. sp. tritici can frequently lead to defeat of wheat stem rust resistance genes. P. graminis f. sp. tritici race TKTTF caused a severe epidemic in Ethiopia on Ug99-resistant ‘Digalu’ in 2013 and 2014. The gene Sr11 confers resistance to race TKTTF and is present in ‘Gabo 56’. We identified seven single-nucleotide polymorphism (SNP) markers linked to Sr11 from a cross between Gabo 56 and ‘Chinese Spring’ exploiting a 90K Infinium iSelect Custom beadchip. Five SNP markers were validated on a ‘Berkut’/‘Scalavatis’ population that segregated for Sr11, using KBioscience competitive allele-specific polymerase chain reaction (KASP) assays. Two of the SNP markers, KASP_6BL_IWB10724 and KASP_6BL_IWB72471, were predictive of Sr11 among wheat genetic stocks, cultivars, and breeding lines from North America, Ethiopia, and Pakistan. These markers can be utilized to select for Sr11 in wheat breeding and to detect the presence of Sr11 in uncharacterized germplasm.


Plant Disease ◽  
2010 ◽  
Vol 94 (6) ◽  
pp. 784-784 ◽  
Author(s):  
Z. A. Pretorius ◽  
C. M. Bender ◽  
B. Visser ◽  
T. Terefe

Isolates of Puccinia graminis f. sp. tritici belonging to the Ug99 race group are virulent to a broad spectrum of resistance genes, rendering most of the world's wheat germplasm susceptible to stem rust (3). Following the initial detection of Ug99 (TTKSK, North American [NA] race notation) in Uganda, virulence to the widely used Sr31 resistance gene has been reported from Kenya, Ethiopia, Sudan, and Iran (2,3). In November 2009, a wheat genotype suspected to carry Sr31 showed a susceptible response to stem rust in a disease nursery (29°08′05.02′′S, 30°38′29.18′′E), inoculated with race TTKSP, near Greytown in KwaZulu-Natal, South Africa. Inoculation of urediniospores of the field collection (isolate UVPgt60) onto seedlings of line Federation4*/Kavkaz confirmed virulence for Sr31. In three independent, replicated, and comparative seedling tests, eight single-pustule isolates of UVPgt60 all typed to race PTKST following the NA race nomenclature. These isolates produced compatible infection types (ITs) (3+ to 4) on the Sr31 testers Gamtoos, Sr31/6*LMPG, Federation4*/Kavkaz, Kavkaz, and Clement, whereas isolate UVPgt59 (TTKSP) was avirulent (ITs ;1 to 1) on these genotypes. In addition to Sr31 virulence, the new race differed from TTKSP by producing a lower IT (2 to 2++) on Cns_T.mono_ deriv., the accepted entry for Sr21 in the NA differential set. The UVPgt60 isolates were clearly avirulent on Einkorn (Sr21) (IT ;1=), a response that also differed from those produced by BPGSC, TTKSF, and TTKSP (IT 2). With the exception of Sr21, UVPgt60 isolates had a virulence pattern similar to race TTKST (1), notably the virulence combination for Sr24 and Sr31. Isolate UVPgt60.6 was randomly selected for testing on additional Sr genes and South African wheat cultivars and breeding lines. Similar to the race identification experiments seedling tests were duplicated and compared with reactions produced by TTKSP and other races. Greenhouse temperatures for all seedling tests ranged between 18 and 25°C. On the basis of primary leaf responses, PTKST is avirulent (ITs 0; to 2++) for Sr13, 14, 21, 22, 25, 26, 27, 29, 32, 33, 35, 36, 37, 39, 42, 43, 44, Em, Tmp, and Satu and virulent (ITs 3 to 4) for Sr5, 6, 7b, 8a, 8b, 9a, 9b, 9d, 9e, 9g, 10, 11, 16, 17, 24, 30, 31, 34, 38, 41, and McN. From 103 South African wheat cultivars and lines tested as seedlings, 59 and 47 were susceptible (IT ≥ 3) to races PTKST and TTKSP, respectively. Simple-sequence repeat analysis (4) with selected primer pairs showed that PTKST clusters with isolates belonging to the Ug99 lineage. Subsequent to the collection made at Greytown, stem rust sampled in December 2009 from naturally infected breeders' lines at Cedara (29°32′19.59′′S, 30°16′03.50′′E), KwaZulu-Natal, revealed five isolates with a virulence profile similar to PTKST. On the basis of current evidence it appears that PTKST may be an introduction to South Africa rather than a single-step mutation from local stem rust races. References: (1) Y. Jin et al. Plant Dis. 92:923, 2008. (2) K. Nazari et al. Plant Dis. 93:317, 2009. (3) R. P. Singh et al. Adv. Agron. 98:271, 2008. (4) B. Visser et al. Mol. Plant Pathol. 10:213, 2009.


2007 ◽  
Vol 58 (6) ◽  
pp. 593 ◽  
Author(s):  
Z. A. Pretorius ◽  
K. W. Pakendorf ◽  
G. F. Marais ◽  
R. Prins ◽  
J. S. Komen

The cultivation of small grain cereals was introduced to South Africa by Dutch settlers in the 17th Century. According to historical records the first documented epidemic of wheat stem rust occurred in the south-western parts of the current Western Cape in 1726. Recurring stem and leaf rust epidemics were associated with expanding wheat production and became particularly severe in the winter-rainfall regions of the Western and Eastern Cape, as well as in the summer-rainfall regions of the Free State. The wheat stripe rust pathogen was first detected in South Africa in 1996. Due to susceptibility of cultivars at the time of this exotic introduction, stripe rust has caused significant losses in commercial wheat production over the past 10 years. Pathotype surveys of Puccinia graminis and P. triticina were initiated in the 1920s, but were discontinued until research on wheat stem rust was resumed in the 1960s. Recent evidence has shown that P. graminis f. sp. tritici continues to evolve. In addition, the annual number of wheat stem rust collections is increasing, emphasising the sustained threat of this damaging pathogen. A stem rust pathotype first detected in 2000, with newly acquired virulence for Sr8b and Sr38, currently constitutes more than 80% of all collections. Leaf and stem rust diseases also occur on barley, oat, triticale, and rye and are important production constraints in several regions. Some studies have described variability in these pathogens but long-term records of pathogenicity changes in barley and oat rust are not available. Cereal rust diseases have clearly played an important role in South African agriculture and many production regions remain favourable for rust development. Current expertise in cereal rusts covers most technologies necessary to study the respective host–pathogen systems. However, a general lack of capacity and fragmentation of research groups prevent a unified approach and remain a challenge for sustainable cereal rust control in South Africa. A national strategy for cereal rust control, with particular emphasis on pathogen and host resources, and breeding for resistance, is urgently needed.


2020 ◽  
Author(s):  
Neven Chetty ◽  
Bamise Adeleye ◽  
Abiola Olawale Ilori

BACKGROUND The impact of climate temperature on the counts (number of positive COVID-19 cases reported), recovery, and death rates of COVID-19 cases in South Africa's nine provinces was investigated. The data for confirmed cases of COVID-19 were collected for March 25 and June 30, 2020 (14 weeks) from South Africa's Government COVID-19 online resource, while the daily provincial climate temperatures were collected from the website of the South African Weather Service. Our result indicates that a higher or lower climate temperature does not prevent or delay the spread and death rates but shows significant positive impacts on the recovery rates of COVID-19 patients. Thus, it indicates that the climate temperature is unlikely to impose a strict limit on the spread of COVID-19. There is no correlation between the cases and death rates, an indicator that no particular temperature range is closely associated with a faster or slower death rate of COVID-19 patients. As evidence from our study, a warm climate temperature can only increase the recovery rate of COVID-19 patients, ultimately impacting the death and active case rates and freeing up resources quicker to enable health facilities to deal with those patients' climbing rates who need treatment. OBJECTIVE This study aims to investigate the impact of climate temperature variation on the counts, recovery, and death rates of COVID-19 cases in all South Africa's provinces. The findings were compared with those of countries with comparable climate temperature values. METHODS The data for confirmed cases of COVID-19 were collected for March 25 and June 30 (14 weeks) for South African provinces, including daily counts, death, and recovery rates. The dates were grouped into two, wherein weeks 1-5 represent the periods of total lockdown to contain the spread of COVID-19 in South Africa. Weeks 6-14 are periods where the lockdown was eased to various levels 4 and 3. The daily information of COVID-19 count, death, and recovery was obtained from South Africa's Government COVID-19 online resource (https://sacoronavirus.co.za). Daily provincial climate temperatures were collected from the website of the South African Weather Service (https://www.weathersa.co.za). The provinces of South Africa are Eastern Cape, Western Cape, Northern Cape, Limpopo, Northwest, Mpumalanga, Free State, KwaZulu-Natal, Western Cape, and Gauteng. Weekly consideration was given to the daily climate temperature (average minimum and maximum). The recorded values were considered, respectively, to be in the ratio of death-to-count (D/C) and recovery-to-count (R/C). Descriptive statistics were performed for all the data collected for this study. The analyses were performed using the Person’s bivariate correlation to analyze the association between climate temperature, death-to-count, and recovery-to-count ratios of COVID-19. RESULTS The results showed that higher climate temperatures aren't essential to avoid the COVID-19 from being spread. The present results conform to the reports that suggested that COVID-19 is unlike the seasonal flu, which does dissipate as the climate temperature rises [17]. Accordingly, the ratio of counts and death-to-count cannot be concluded to be influenced by variations in the climate temperatures within the study areas. CONCLUSIONS The study investigates the impact of climate temperature on the counts, recovery, and death rates of COVID-19 cases in all South Africa's provinces. The findings were compared with those of countries with comparable climate temperatures as South Africa. Our result indicates that a higher or lower climate temperature does not prevent or delay the spread and death rates but shows significant positive impacts on the recovery rates of COVID-19 patients. Warm climate temperatures seem not to restrict the spread of the COVID-19 as the count rate was substantial at every climate temperatures. Thus, it indicates that the climate temperature is unlikely to impose a strict limit on the spread of COVID-19. There is no correlation between the cases and death rates, an indicator that there is no particular temperature range of the climatic conditions closely associated with a faster or slower death rate of COVID-19 patients. However, other shortcomings in this study's process should not be ignored. Some other factors may have contributed to recovery rates, such as the South African government's timely intervention to announce a national lockout at the early stage of the outbreak, the availability of intensive medical care, and social distancing effects. Nevertheless, this study shows that a warm climate temperature can only help COVID-19 patients recover more quickly, thereby having huge impacts on the death and active case rates.


Plant Disease ◽  
2011 ◽  
Vol 95 (8) ◽  
pp. 941-944 ◽  
Author(s):  
M. N. Rouse ◽  
Y. Jin

Wheat stem rust, caused by Puccinia graminis f. sp. tritici, has been effectively controlled through the use of genetic resistance. P. graminis f. sp. tritici race TTKSK (Ug99) possesses virulence to many resistance genes that have been used in wheat breeding worldwide. One strategy to aid breeders in developing resistant cultivars is to utilize resistance genes transferred from wild relatives to wheat. Stem rust resistance genes have previously been introgressed from Triticum monococcum to wheat. In order to identify additional resistance genes, we screened 1,061 accessions of T. monococcum and 205 accessions of T. urartu against race TTKSK and four additional P. graminis f. sp. tritici races: TTTTF, TRTTF, QFCSC, and MCCFC. A high frequency of the accessions (78.7% of T. monococcum and 93.0% of T. urartu) were resistant to P. graminis f. sp. tritici race TTKSK, with infection types ranging from 0 to 2+. Among these resistant accessions, 55 T. monococcum accessions (6.4% of the total) were also resistant to the other four races. Associations of resistance in T. monococcum germplasm to different races indicated the presence of genes conferring resistance to multiple races. Comparing the observed infection type patterns to the expected patterns of known genes indicated that previously uncharacterized genes for resistance to race TTKSK exist in both T. monococcum and T. urartu.


2013 ◽  
Vol 18 (1) ◽  
Author(s):  
Jeffrey J. Bagraim

The emigration of skilled nurses from South Africa exacerbates the crisis in the provision of public health services. A descriptive, quantitative design was applied to investigate the relationship between intention to emigrate and employee commitment. Over 400 registered nurses (N = 419), working within public sector tertiary hospitals in the Western Cape, responded to a cross-sectional survey questionnaire. Three foci of employee commitment (organisational, professional and national) were examined but only national commitment significantly helped predict intention to emigrate from South Africa in the regression model (beta = -0.0525, p < 0.0001). The implications of the results obtained in this study are discussed.Die emigrasie van verpleegkundiges uit Suid-Afrika vererger die krisis in die verskaffing van gesondheidsorgdienste in die land. ’n Beskrywende, kwantitatiewe ontwerp is gebruik om die verwantskap tussen werknemertoewyding en die voorneme om te emigreer te ondersoek. Meer as 400 verpleegsters (N = 419) wat in openbare tersiêre hospitale in die Wes-Kaap werk, het op die vraelys gereageer. Drie fokusareas van toewyding (organisatories, professioneel en nasionaal) is gemeet, maar net nasionale toewyding het daartoe bygedra om emigrasievoorneme te voorspel (beta = -0.0525, p < 0.0001). Die implikasies van hierdie resultate word bespreek.


Plant Disease ◽  
2010 ◽  
Vol 94 (4) ◽  
pp. 478-478 ◽  
Author(s):  
L. Mostert ◽  
W. Bester ◽  
T. Jensen ◽  
S. Coertze ◽  
A. van Hoorn ◽  
...  

Southern highbush blueberry plants (Vaccinium corymbosum interspecific hybrids) showing rust-like symptoms were observed in July 2006 in Porterville in the Western Cape (WC), South Africa. Diseased plants were also found in Villiersdorp and George in the WC in 2007. In 2008, symptoms were observed in George, and in 2009, in all the previous reported areas. Cvs. Bluecrisp, Emerald, Jewel, Sharpblue, and Star were infected. Reddish-to-brown spots appeared on the adaxial surface of leaves and developed into yellow-to-orange erumpent uredinia with pulverulent urediniospores. Uredinia were hypophyllous, dome shaped, 113 to 750 μm wide, and occasionally coalescing. Urediniospores were broadly obovate, sometimes ellipsoidal or pyriform, with yellowish orange content, and measured 19 to 27 × 12 to 20 μm (average 24 × 15 μm, n = 30). Spore walls were echinulate, hyaline, 1 to 1.5 μm thick, and with obscure germ pores. No telia or teliospores were observed. Voucher specimens were lodged in the South African National Fungus Collection in Pretoria (PREM 60245). The isolate was initially identified as Thekopsora minima P. Syd. & Syd., based primarily on the absence of conspicuous ostiolar cells characteristic of Naohidemyces spp. (3). Genomic DNA was extracted from urediniospores. Approximately 1,400 bp were amplified spanning the 5.8S, ITS2, and 28S large subunit of the ribosomal DNA (1). The sequence (GU355675) shared 96% (907 of 942 bp; GenBank AF522180) and 94% (1,014 of 1,047 bp; GenBank DQ354563) similarities in the 28S portion, respectively, to those of Naohidemyces vaccinii (Wint.) Sato, Katsuya et Y. Hiratsuka and Pucciniastrum geoppertianum (Kuehn) Kleb, two of the three known rust species of blueberry (2). Although no sequences of T. minima were available for direct comparison, phylogenetic analyses of the 28S region strongly supported the South African blueberry rust as congeneric with T. guttata (J. Schröt.) P. Syd. & Syd. (GenBank AF426231) and T. symphyti (Bubák) Berndt (GenBank AF26230) (data not shown). Four 6-month-old cv. Sharpblue plants were inoculated with a suspension (approximate final concentration of 1 × 105 spores per ml) of fresh urediniospores in a water solution with 0.05% Tween 20. After incubation at 20°C for 48 h under continuous fluorescent lighting, the plants were grown in a glasshouse (18/25°C night/day temperatures). Identical uredinia and symptoms developed approximately 3 weeks after inoculation on the inoculated plants, but not on two control plants of cv. Sharpblue sprayed with distilled water and kept at the same conditions. The alternate host hemlock (Tsuga spp.) is not endemic to South Africa and not sold as an ornamental plant according to a large conifer nursery. Hosts of T. minima include Gaylussacia baccata, G. frondosa, Lyonia neziki, Menziesia pilosa, Rhododendron canadense, R. canescens, R. lutescens R. ponticum, R. prunifolium, R. viscosum, V. angustifolium var. laevifolium, V. corumbosum, and V. erythrocarpon (3). Visual inspection of possible hosts in the gardens in close proximity of Vaccinium production areas did not show any rust symptoms. To our knowledge, this is the first report of T. minima on blueberries outside of Asia and the United States (2). References: (1) M. C. Aime. Mycoscience 47:112, 2006. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Botany and Mycology Laboratory. Online publication. USDA-ARS, 2009. (3) S. Sato et al. Trans. Mycol. Soc. Jpn. 34:47, 1993.


Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2050
Author(s):  
Tanya Nadia Glatt ◽  
Caroline Hilton ◽  
Cynthia Nyoni ◽  
Avril Swarts ◽  
Ronel Swanevelder ◽  
...  

Background: COVID-19 convalescent plasma (CCP) has been considered internationally as a treatment option for COVID-19. CCP refers to plasma collected from donors who have recovered from and made antibodies to SARS-CoV-2. To date, convalescent plasma has not been collected in South Africa. As other investigational therapies and vaccination were not widely accessible, there was an urgent need to implement a CCP manufacture programme to service South Africans. Methods: The South African National Blood Service and the Western Cape Blood Service implemented a CCP programme that included CCP collection, processing, testing and storage. CCP units were tested for SARS-CoV-2 Spike ELISA and neutralising antibodies and routine blood transfusion parameters. CCP units from previously pregnant females were tested for anti-HLA and anti-HNA antibodies. Results: A total of 987 CCP units were collected from 243 donors, with a median of three donations per donor. Half of the CCP units had neutralising antibody titres of >1:160. One CCP unit was positive on the TPHA serology. All CCP units tested for anti-HLA antibodies were positive. Conclusion: Within three months of the first COVID-19 diagnosis in South Africa, a fully operational CCP programme was set up across South Africa. The infrastructure and skills implemented will likely benefit South Africans in this and future pandemics.


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