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SARS-CoV-2 ou b eak in es iga ion in a Ge man mea p ocessing plan
Thomas Gün he 1§, Manja Czech-Sioli2, Daniela Indenbi ken1, Alexis Robi aille1, Pe e
Tenhaken3, Ma in Exne 4, Ma hias O inge 5, Nicole Fische 2*, Adam G undho 1§*,
Melanie M. B inkmann6,7*
1Hein ich Pe e Ins i u e, Leibniz Ins i u e o Expe imen al Vi ology, Hambu g,
Ge many; 2Ins i u e o Medical Mic obiology, Vi ology and Hygiene, Uni e si y
Medical Cen e Hambu g-Eppendo , Hambu g, Ge many; 3Heal h O ice, Osnab ück,
Ge many; 4Ins i u e o Hygiene and Public Heal h, Uni e si y o Bonn, Bonn, Ge many;
5Omik on Sys ems GmbH, B aunschweig, Ge many;
6Vi al Immune Modula ion Resea ch G oup, Helmhol z Cen e o In ec ion Resea ch,
B aunschweig, Ge many; 7Ins i u e o Gene ics, Technische Uni e si ä B aunschweig,
B aunschweig, Ge many
§equal con ibu ion
* Co esponding au ho s: Melanie M. B inkmann, m.b inkm[email p o ec ed],
phone: +49-531-6181-3069; Nicole Fische , [email p o ec ed], phone: +49-40-7410-
55171; Fax: +49-40-7410-53250; Adam G undho , adam.g undho @leibniz-hpi.de;
phone: +49-40-48051-275; Fax: +49-40-48051-277
Cha ac e coun o he manusc ip : 25,613 cha ac e s/4,732 wo ds
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Abs ac
We desc ibe a mul i ac o ial in es iga ion o a SARS-CoV-2 ou b eak in a la ge mea
p ocessing complex in Ge many. In ec ion e en iming, spa ial, clima e and en ila ion
condi ions in he p ocessing plan , sha ing o li ing qua e s and anspo , and i al
genome sequences we e analyzed. Ou esul s sugges ha a single index case ansmi ed
SARS-CoV-2 o co-wo ke s o e dis ances o mo e han 8 me e s, wi hin a con ined wo k
a ea in which ai is cons an ly eci cula ed and cooled. Vi al genome sequencing shows
ha all cases sha e a se o mu a ions ep esen ing a no el sub-b anch in he SARS-CoV-2
C20 clade. We iden i ied he same se o mu a ions in samples collec ed in he ime pe iod
be ween his ini ial in ec ion clus e and a subsequen ou b eak wi hin he same ac o y,
wi h he la ges numbe o con i med SARS-CoV-2 cases in a Ge man mea p ocessing
acili y epo ed so a .
Ou esul s indica e clima e condi ions, esh ai exchange a es, and ai low as ac o s ha
can p omo e e icien sp ead o SARS-CoV-2 ia long dis ances and p o ide insigh s in o
possible equi emen s o pandemic mi iga ion s a egies in indus ial wo kplace se ings.
Keywo ds
Ae osol ansmission/mea p ocessing plan ou b eak/SARS-CoV-2 supe sp eading
e en / i al genome sequencing
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In oduc ion
The i s wa e o SARS-CoV-2 in ec ions peaked in Eu ope om Ma ch o mid o May
2020. Implemen a ion o social and physical dis ancing measu es esul ed in declining
in ec ion numbe s in mos Eu opean coun ies. Cu en ly, coun ies seek o implemen
al e na i e measu es, o example in ec ion managemen ocused on ho spo s, con ac
acing and sen inel es ing. Gi en his, i is impo an o immedia ely ollow up on local
in ec ion clus e s o p e en e-eme gence o la ge-scale communi y ansmission as seen
du ing he i s wa e o SARS-CoV-2 in ec ions.
T ansmission o SARS-CoV-2 is hough o mainly occu ia espi a o y up ake o d ople s
( an Do emalen, Bushmake e al., 2020) o ae osols. Ae osols a e belie ed o be
pa icula ly impo an in cases whe e a single sou ce ansmi s he i us o a la ge numbe
o indi iduals, so-called supe sp eading e en s (Dyal, G an e al., 2020, On Kwok, Hin
Chan e al., 2020, Schwie zeck, Konig e al., 2020, Xu, Liu e al., 2020, Yuse , Hayajneh
e al., 2020, Zhang, Diao e al., 2020, Zhang, Li e al., 2020). Whe eas d ople s ypically
a el no a he han 2 m, ae osols can s ay in he ai o p olonged pe iods o ime and
may deli e in ec ious i al pa icles subs an ially beyond 2m dis ances, especially in
indoo se ings wi h low esh ai exchange a es (Asadi, Wexle e al., 2019, Asadi, Wexle
e al., 2020, Liu, Li e al., 2017). Fac o s such as empe a u e, humidi y and ai ci cula ion
a e hough o signi ican ly in luence s abili y and anspo o d ople s and ae osols and
consequen ly ansmission e iciency ( an Do emalen e al., 2020).
Mea p ocessing plan s ha e ecen ly eme ged as ho spo s o SARS-CoV-2 a ound he
wo ld. This is hough o esul no only om ope a ional p ac ices (e.g. close p oximi y o
wo ke s in he p oduc ion line combined wi h physically demanding wo k ha p omo es
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hea y b ea hing), bu also om sha ing o housing and anspo a ion ha may acili a e
i al ansmission (Dyal e al., 2020). The equi emen o ope a e a low empe a u e in an
en i onmen wi h low ai exchange a es is ano he ac o ha may p omo e sp ead o he
i us among wo ke s. Howe e , di ec scien i ic e idence o he na u e o ansmission
e en s in a mea p ocessing plan o he ole o sha ed housing and anspo a ion has no
been epo ed ye .
He e, we epo a ansmission clus e in a Ge man mea p ocessing plan in May 2020 and
p o ide da a sugges ing ha en i onmen al condi ions p omo ed i al ansmission om a
single index case o mo e han 60% o co-wo ke s wi hin a dis ance o 8 me e s. Vi al
sequence analyses e ealed a p e iously un epo ed SARS-CoV-2 geno ype ha is no only
sha ed by all indi iduals o he ini ial clus e , bu also by samples collec ed sho ly be o e
a subsequen ou b eak in mid-June, which ep esen s he la ges ou b eak in a mea
p ocessing plan seen in Ge many hus a . Ou indings indica e ha a physical dis ance
o 2 me e s does no su ice o p e en ansmission in en i onmen al condi ions such as
hose s udied he e; addi ional measu es such as imp o ed en ila ion and ai low,
ins alla ion o il e ing de ices o use o high-quali y ace masks a e equi ed o educe he
in ec ion isk in hese en i onmen s.
Resul s
We s udied an ou b eak in he la ges mea p ocessing plan in Ge many, loca ed in Rheda-
Wiedenb ück, coun y o Gü e sloh, s a e o No h Rhine Wes alia ( e e ed o as MPP-R
in he ollowing). MPP-R pe o ms slaugh e and ine p ocessing as well as packaging o
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bee and po k. A second, independen ly ope a ed p ocessing plan specialized on sow
deboning (MPP-D in he ollowing) is loca ed in Dissen (coun y o Osnab ück, s a e o
Lowe Saxony), app oxima ely 30 km away om MPP-R. Due o occasional SARS-CoV-
2 posi i e cases in he Ge man mea indus y, se e al s a e go e nmen s in Ge many
a anged SARS-CoV-2 PCR-based se ies es ing o he en i e s a o mea p ocessing
plan s in May 2020, including MPP-D and MPP-R.
Se ies o e en s p eceding he ou b eak in mea p ocessing plan R (MPP-R)
As shown in Fig. 1A, go e nmen manda ed se ies es ing in MPP-D and MPP-R ook
place in he week o May 11. Tes esul s we e epo ed on Sunday May 17. 94 ou o 279
es ed MPP-D employees we e ound o be SARS-CoV-2 posi i e, sugges ing an ongoing
ou b eak among MPP-D wo ke s. In MPP-R, only ou ou o a o al o 6,289 employees
we e ound o be posi i e.
None o he ou cases in MPP-R was in ol ed in mea p ocessing and he cases we e
judged o likely be independen . On Tuesday May 19 (Fig. 1B), wo MPP-R wo ke s om
he ea ly shi ( e e ed o as cases B1 and B2 in he ollowing) epo ed o he managemen
o ha ing had a b ie con ac wi h employees om MPP-D (D1 and D2 in he ollowing)
on Sunday May 17, bo h o whom had ecei ed posi i e es esul s la e ha day (Fig. 1A).
Cases B1 and B2 epo ed o ha e no symp oms.
SARS-CoV-2 ou b eaks in MPP-R du ing May and June 2020
B1 and B2 we e es ed in he company’s es cen e on May 20 (Fig. 1B). Because he
con ac wi h MPP-D wo ke s was no classi ied as high isk, bo h con inued o wo k. On

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May 21, he ea ly shi did no wo k due o a holiday. Upon ecei ing posi i e es esul s
on May 21, B1 and B2 and i e wo ke s wi h whom hey had sha ed an apa men we e
qua an ined. B1 and B2 we e mo ed o a sepa a e apa men , whe eas hei la ma es
emained in hei o iginal qua e s. On Monday May 25, all emaining wo ke s om he
ea ly shi (n=140) we e es ed. Tes esul s om May 27 ound 18 ea ly shi wo ke s o
be posi i e. All ea ly shi wo ke s we e immedia ely qua an ined he ea e . Follow-up
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es ing pe o med be ween May 27 and June 3 iden i ied ano he 11 posi i e cases among
he al eady qua an ined wo ke s.
Following his ou b eak in May, isk- and e idence-based sc eening pe o med by heal h
au ho i ies, gene al p ac i ione s and he in e nal MPP-R es cen e iden i ied inc easing
numbe s (>110) o posi i e cases ac oss di e en pa s o he plan in June, sugges ing an
ongoing and mo e wide-sp ead second ou b eak e en . Indeed, subsequen se ies es ing
by heal h au ho i ies be ween June 17 and 23 iden i ied mo e han 1,400 posi i e cases,
cons i u ing he la ges ou b eak in a Ge man mea p ocessing acili y seen hus a (Fig.
1C).
Vi al geno ypes in he May 2020 ou b eak
The iming o e en s sugges ed employees B1 and B2 as he mos likely sou ce(s) o he
ea ly MPP-R in ec ion clus e . To u he subs an ia e his hypo hesis, we pe o med ull
i al genome sequencing o he 20 cases es ed posi i e by May 27. In Fig. 2A, we p esen
a hea map showing posi ions and colo -coded equency alues o nucleo ide de ia ions
om he Wuhan SARS-CoV-2 e e ence s ain.
A o al o eigh exchanges we e ound wi h nea 100% equency ac oss all samples. A
sea ch agains 56,366 ull leng h sequences a ailable h ough GISAID iden i ied six o
hese mu a ions o be commonly p esen in he 20C clade o SARS-CoV-2, a b anch which
accoun s o app oxima ely 17% o all SARS-CoV-2 sequences deposi ed in GISAID a
he ime o his w i ing. In e es ingly, howe e , we did no ind GISAID en ies sha ing he
wo emaining mu a ions (ma ked wi h as e isks in Fig. 2A; see Appendix Table S1 and
Figu e S3 o u he de ails). Combined, he eigh mu a ions he e o e ep esen a no el
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sub-b anch wi hin he 20C clade ha de ines he p o o ypical i al genome signa u e o he
in ec ion clus e (submi ed o GISAID, accession numbe 476705, s ain id NRW-MPP-
1). Whe eas he B1 sequence is an exac p o o ype ep esen a i e, we ind an addi ional
nucleo ide exchange a 100% equency (C7735T) in B2. The ac ha his mu a ion is
absen om he o he samples ules ou B2 as a possible sou ce o he clus e wi h nea
ce ain y. Ano he six cases also exhibi a single addi ional nucleo ide exchange ha is no
sha ed wi h any o he sample.
Taken oge he , hese obse a ions sugges p o o ype i us ansmission by B1 as he
common sou ce o in ec ion in he clus e . Gi en he o e all sca ci y o non-p o o ypical
nucleo ide a ian s, he p esence o addi ional exchanges mos likely esul ed om ongoing
i al mu agenesis in a subse o newly in ec ed indi iduals. Howe e , he sequencing da a
alone canno ule ou he o mal possibili y ha a leas some o hese a ian s ep esen
independen in ec ion e en s.
Po en ial ansmission ou es in he May 2020 ou b eak
Gi en he abo e, we in es iga ed po en ial ansmission ou es be ween he suspec ed
index case B1 and he o he employees wi hin he clus e . The uni e sal poin o po en ial
con ac among all cases was wo k in he ea ly shi o he bee p ocessing plan . The shi
comp ises 147 indi iduals, mos o whom wo k a ixed posi ions in a con eyo -bel
p ocessing line. The p ocessing line occupies an elonga ed a ea app oxima ely 32 me e s
(m) long and 8.5 m wide (see loo plan in Appendix Fig. S1A). Qua e s o bee en e a
one end o he line ( e e ed o as p oximal in he ollowing) and a e p ocessed as hey
mo e in longi udinal di ec ion ac oss he oom, un il cu s a e inally packaged nea he a
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end o he line ( e e ed o as dis al in he ollowing). Eigh ai condi ioning uni s placed
nea he ceiling in he p oximal hal o he oom cons an ly cool he ai . Fans p ojec he
ai in a la e al di ec ion, ei he di ec ly om on al openings in he uni o ia pe o a ed
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commi ee issued a s a emen o no objec ion o publish he s udy unde e e ence numbe
337/20.
SARS-CoV-2 amplicon sequencing and bioin o ma ic analysis
Sample p epa a ion o SARS-CoV-2 amplicon sequencing was pe o med as desc ibed
(J., 2020) wi h modi ica ions (P e e le, Guen he e al., 2020). P ime sequences a e
p o ided in he Appendix Table S4. Samples we e sequenced on an Illumina MiSeq using
500cycle MiSeq 2 eagen ki s (Illumina). All samples we e sequenced wice (including
independen cDNA syn hesis and lib a y p epa a ion eac ions) o exclude he possibili y
o a ian equencies esul ing om andom ampli ica ion a i ac s. Excep o sample
B14 (in which one sequencing eac ion was excluded due o insu icien quali y), epo ed
a ian equencies e lec he a e age alues om independen eplica es. Bioin o ma ic
analysis was pe o med as desc ibed (P e e le e al., 2020), (see Appendix Table S5 o
de ails on he amplicon-Seq s a is ics), wi h he ollowing modi ica ions: Inpu h esholds
we e se o a leas 10 a ian suppo ing eads wi h a minimum base quali y o 30 (-C10 -
q30). Only high con idence a ian s p esen in > 20% o eads in a leas one indi idual
sample we e included and anno a ed using ANNOVAR 16. Mino equency a ian s
esul ing in ame shi , s opgain o s a loss we e excluded.
Compa ison o i al geno ypes wi h GISAID da abase en ies
We pe o med a blas sea ch o he p o o ypical NRW-MPP-1 geno ype iden i ied in his
s udy agains all 56,366 sequences deposi ed in GISAID as o July 6, 2020. None o he
en ies con ained he combina ion o he wo nucleo ide a ian s C6406T and G18972A ha

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a e sha ed ac oss all samples in es iga ed in ou s udy. As shown in Appendix Table S6, a
e y limi ed numbe (23 ou o 56,366 sequences) con ain one o he wo mu a ions. Two
samples om he US (collec ed on he same da e as B1 and B2) also ca y he a ian
C6406T, bu addi ionally exhibi ano he 7 and 8 mu a ions. These samples clea ly belong
o a di e en sub-b anch o clade 20C de ined by a p e iously in oduced mu a ion a
posi ion 27964. 21 samples om he UK also con ain one o he wo mu a ions bu belong
o he sepa a e clade 20B. The occu ence o hese a ian s in di e en clade iden i ies
hem as homoplasies and sugges s ha hese isola es a e no closely ela ed o he NRW-
MPP-1 geno ype.
S a is ical analysis
P- alues in Fig. 3B and Appendix Table S2 indica e he cumula i e p obabili y o in ec ion
a es among wo ke s wi h ixed s a ions in he indica ed dis ance anges being equal o
highe han obse ed, unde he null hypo hesis ha he p obabili y o any gi en indi idual
being posi i e is independen o spa ial loca ion and e lec s o e all posi i e a es among
wo ke s wi h ixed s a ions a ound he index case (20 ou o 78 = 25.6%; see Appendix
Table S2). Simila ly, o each sha ed uni in Fig. 3C and Appendix Table S3 we calcula ed
p- alues o in ec ion equencies being equal o highe han obse ed among all
indi iduals who sha e one o mo e uni (22 ou o 65 = 33.8%; please no e ha due o da a
p o ec ion egula ions we canno e eal which wo ke IDs belong o a sha ed uni ).
Cumula i e p obabili y mass alues we e calcula ed using he BINOM.DIST.RANGE
unc ion om Mic oso Excel o Mic oso 365 MSO ( 16.0.12827.20328) wi h he
ollowing inpu alues: p obabili y p: a e age in ec ion a e among wo ke s wi h ixed
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s a ions (0.256) o wo ke s sha ing one o mo e uni (0.338), minimum numbe o
successes s: obse ed numbe o posi i e wo ke s in dis ance ange o sha ed uni , ials
and maximum numbe o successes s2: : o al numbe o wo ke s in dis ance ange o
sha ed uni .
Desc ip ion o housing condi ions, wo k a ea condi ions, and wo king condi ions
Housing condi ions: Many o he wo ke s sha e apa men s and hose usually commu e
oge he o hei wo kplace in ans o ganized by he company. The company p o ided us
wi h anonymized in o ma ion abou he housing si ua ion o he wo ke s ega ding
in o ma ion on sha ed apa men s, bed ooms and ca pools. The la ges housing uni
encompassed se en wo ke s o he ini ial ou b eak in May in he bee p ocessing plan
(see Appendix Table S3; no e ha due o da a p o ec ion egula ions we canno e eal
which wo ke s belong o indi idual sha ed uni s). In addi ion, we collec ed in o ma ion
abou he wo k a ea and he wo king condi ions du ing ou on-si e isi on June 2 2020.
Du ing ha isi , we isi ed he bee p ocessing plan du ing ope a ing hou s accompanied
by echnical s a om MPP-R.
Wo k a ea condi ions: The plan comp ises sepa a e a eas in which slaugh e ing and mea
p ocessing is pe o med. While slaugh e ing akes place a ambien empe a u es wi h
highe ai exchange a es, bee and po k p ocessing a e pe o med in ooms cooled o
app oxima ely 10°C wi h a high p opo ion o eci cula ed cooled ai . The bee p ocessing
plan has a size o 2,800 m2 and is 6.1 m high (Appendix Figu e S1A-B). The en i e oom
and he p oduc ion line a e cleaned and disin ec ed daily acco ding o ood hygiene
egula ions in Ge many. On he day o he on-si e isi , he empe a u e in a ea 1 and 2 in
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he bee p ocessing plan anged be ween 9.5-10.7°C and be ween 5.4-8.7°C in a ea 3.
Rela i e humidi y was measu ed o be 34% igh below he cooling ans in a ea 1 and 68%
in he emaining pa o a ea 1, and be ween 67-71% in a eas 2 and 3 (Appendix Figu e
S1A).
Cooling ans a e cooling eci cula ed ai wi hou il e s (C1-8). C3-8 a e connec ed o a
pe o a ed hose di ec ed owa ds a ea 3 whe eas C1 and C2 lack a hose. C1 and C2 u n on
only when empe a u es ise abo e 10°C. Cooled ai is expelled h ough he hall up o
app oxima ely 12 me e s. Cooling ans 3-8 a e ope a ing pe manen ly and a e expelling
cooled ai h ough a ached pe o a ed hoses. The ai exchange a e o he en i e bee
p ocessing plan is <1. This means ha i akes mo e han one hou o ha e he ai eplaced
by esh ai . Speci ica ion o he cooling ans is as ollows: Manu ac u e : Guen he AG &
Co. KG, Fue s en eldb uck, Ge many, Model: S-GGHF 50Hz, Type 050.1E/17-AS,
capaci y 18,6 kW, ai low 6440 m3/h, ai h ow 37 m, dimensions: Leng h 1363 mm,
Heigh 747 mm, Dep h 713 mm.
Wo king condi ions: The wo ke s in he bee p ocessing plan ha a e wo king on he
pla o m (p oximal side) and he connec ed p ocessing line (s a ing in a ea 1 and ending
in he middle o a ea 2) a e ained o speci ic cu s and he e o e ha e ixed wo kplaces
(Appendix Figu e S1). Hence, wo ke s could be aced in de ail du ing hei wo king hou s.
While 5-6 wo ke s handle he bee qua e s en e ing he plan on he pla o m and p epa e
hem o cu ing, he qua e s a e hen ansloca ed on o h ee con eyo -bel p ocessing
lines whe e 24-25 wo ke s sepa a e he mea om he bones. Nex , ine cu s a e pe o med
(shea ing) by 26-27 wo ke s. Towa ds he dis al pa o he plan as well as in a ea 3, he
bee is packed in o acuum packaging (Appendix Figu e S1B). While he p oduc ion line
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wo ke s ha e ixed wo kplaces, he supe iso y s a has lexible wo kplaces and
commu es wi hin he bee p ocessing plan .
Shi s in he bee p ocessing plan change once pe day. The s a o ea ly and la e shi s
a e p o ided by wo independen sub-con ac o s and hence no s a is exchanged be ween
he shi s. A shi has wo 30 min b eaks and one b eak o one hou . Du ing b eaks, he
wo ke s om a shi isi he can een. Wo ke s do no ha e ixed sea s in he can een.
Supe iso y s a does no spend he b eak imes oge he wi h he p oduc ion line wo ke s.
The supe iso s do no sha e housing o anspo acili ies wi h he p oduc ion line
wo ke s.
Measu es implemen ed by MPP-R du ing SARS-CoV-2 pandemic
Wi h he onse o he SARS-CoV-2 pandemic, addi ional p e en i e measu es o he
p oduc ion s a we e imposed by MPP-R. The company adhe ed o he ecommenda ions
o he ele an occupa ional Heal h and sa e y guidelines (BGN “E gänzung de
Ge äh dungsbeu eilung im Sinne des SARS-CoV-A bei sschu zs anda ds B anche
Fleischwi scha ”). Addi ional measu es we e de eloped and implemen ed by he
company. Hygiene egula ions like hand hygiene and one-way a ic in hallways we e
ein o ced, and an in e nal mul i-lingual in o ma ion campaign was en olled o aise
awa eness o p e en ion and sel -de ec ion o ea ly COVID-19 symp oms. A body
empe a u e he mo scanne was se up o check all employees’ body empe a u e en e ing
he building. Wo ke s ha e been made awa e o he company’s SARS-CoV-2 es cen e
and we e mo i a ed o epo any e en s whe e hey see hemsel es being a isk. Speci ic
wo kplace assessmen s we e pe o med o deciphe possibili ies o ex end dis ances
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be ween wo ke s. Simple one-laye ace masks we e made compulso y. Regula ions we e
in place o p ohibi o a ion be ween wo king places o he wo ke s. Measu es in he
can een we e imposed o educe physical con ac and o en o ce ha wo ke s would spend
hei b eak imes exclusi ely wi h wo ke s om hei own shi . Since he ou b eak o he
pandemic, he company managed o p e en in a-company in ec ion chains un il he e en
desc ibed in his pape . The implemen a ion o he measu es was audi ed on May 15 and
May 29 by unannounced inspec ions o he Occupa ional Heal h and Sa e y Expe s o he
compe en au ho i y and on May 20 by he Occupa ional Heal h and Sa e y expe s o he
“Be u sgenossenscha Nah ungsmi el und Gas gewe be”. The company had se up hei
own es cen e o PCR-based SARS-CoV-2 es ing in ea ly May 2020. In he SARS-CoV-
2 es cen e ained s a akes o opha yngeal swap samples om wo ke s and o he s a .
The samples we e analysed by RT-qPCR in an acc edi ed labo a o y (Labo Kneißle
GmbH & Co.KG, Bu glengen eld, Ge many). S a was es ed based on sel - epo ed
symp oms, possible con ac s o o he in ec ed pe sons, e u ning o wo k a e mo e han
96 h absence om wo k, o based on isk-assessmen o possible wo kplace con ac s.
Da a a ailabili y
Vi us sequence da a ha e been deposi ed a Eu opean Nucleo ide A chi e, ENA,
h ps://www.ebi.ac.uk/ena/; Accession numbe : PRJEB40387. Vi us sequences a e also
a ailable a GISAID, www.gisaid.o g, see Appendix Table S1 o he indi idual accession
link in o ma ion.

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Acknowledgmen s
We hank Ge eon Schulze Al ho , Di k Moo mann, Ca h in Becke , Uwe Golling, Holge
Scholze and Dennis Junkmann om Tönnies Lebensmi el GmbH & Co. KG, Rheda-
Wiedenb ück, Ge many, o sha ing in o ma ion necessa y o he ou b eak in es iga ion
and he possibili y o isi he si e o he ou b eak. We hank Johannes Knobloch and Ma in
Aep elbache , Ins i u e o Medical Mic obiology, Vi ology and Hygiene, UKE, and
Thomas Schulz, Ins i u e o Vi ology, Hanno e Medical School, o help ul discussions
on he manusc ip . We also g ea ly app ecia e he suppo o and aluable discussions wi h
Anna Kebschull, Land ä in Osnab ück, Ge many. We hank he coun y’s heal h au ho i ies
in ol ed in he ou b eak managemen o hei suppo . This wo k is suppo ed by he
Helmhol z Associa ion, Ge many (W2/W3-090). MMB is suppo ed by he SMART
BIOTECS alliance be ween he Technische Uni e si ä B aunschweig and he Leibniz
Uni e si ä Hanno e , an ini ia i e suppo ed by he Minis y o Science and Cul u e
(MWK) o Lowe Saxony, Ge many. AG is suppo ed by he Fede al Minis y o Heal h,
Ge many (HPI-COVID-19).
Au ho Con ibu ions
TG, AG, MO, NF, and MMB designed he s udy. TG, AG, ME, MO, NF, and MMB
pe o med li e a u e sea ch; AG, MO, NF, and MMB w o e he manusc ip ; TG, MCS, DI,
AG, ME, MO, NF, PT, and MMB collec ed he da a. TG, AR, and AG pe o med
bioin o ma ic da a analysis; TG, AG, MO, NF, and MMB gene a ed he igu es and ables,
PT e iewed he manusc ip .
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Con lic o In e es
The au ho s decla e ha hey ha e no con lic o in e es .
Fo Mo e In o ma ion
GISAID Ini ia i e; h ps://www.gisaid.o g
ENA B owse - Eu opean Nucleo ide A chi e; h ps://www.ebi.ac.uk/ena
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The Pape Explained
P oblem
O igina ing om an index case ha had sel - epo ed p e ious con ac wi h po en ially
SARS-CoV-2 in ec ed pe sons, we desc ibe he i s clus e o SARS-CoV-2 ansmission
in a mea p ocessing plan in a con ined wo king a ea. This in ec ion clus e p eceded a
la ge SARS-CoV-2 ou b eak in he same mea p ocessing plan sho ly he ea e in ol ing
1,413 SARS-CoV-2 posi i e es ed employees.
Resul s
By pe o ming a mul i ac o ial analysis o housing and commu ing pa ame e s along wi h
spa ial and clima e condi ions in he wo k a ea and i al genome sequencing, his s udy
p o ides e idence ha ansmission occu ed likely ia ai bo ne ansmission o SARS-
CoV-2 o e long dis ances in a con ined a ea o he mea p ocessing plan . Physical wo k
and ela i ely low esh ai exchange a es oge he wi h con inuous eci cula ion o cooled
ai may ha e a o ed he ansmission o SARS-CoV-2 among employees.
Impac
Ou s udy implica es ha common ope a ional condi ions in indus ial mea p ocessing
plan s p omo e he isk o SARS-CoV-2 supe sp eading e en s. Addi ional measu es such
as imp o ed en ila ion, op imized ai low managemen , ins alla ion o il e ing de ices o
he use o high-quali y ace masks a e equi ed o educe he in ec ion isk in hese
en i onmen s.
Re e ences
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