\documentclass[10pt]{article}

\usepackage{fullpage}
\usepackage{setspace}
\usepackage{parskip}
\usepackage{titlesec}
\usepackage[section]{placeins}
\usepackage{xcolor}
\usepackage{breakcites}
\usepackage{lineno}
\usepackage{hyphenat}





\PassOptionsToPackage{hyphens}{url}
\usepackage[colorlinks = true,
            linkcolor = blue,
            urlcolor  = blue,
            citecolor = blue,
            anchorcolor = blue]{hyperref}
\usepackage{etoolbox}
\makeatletter
\patchcmd\@combinedblfloats{\box\@outputbox}{\unvbox\@outputbox}{}{%
  \errmessage{\noexpand\@combinedblfloats could not be patched}%
}%
\makeatother


\usepackage{natbib}




\renewenvironment{abstract}
  {{\bfseries\noindent{\abstractname}\par\nobreak}\footnotesize}
  {\bigskip}

\titlespacing{\section}{0pt}{*3}{*1}
\titlespacing{\subsection}{0pt}{*2}{*0.5}
\titlespacing{\subsubsection}{0pt}{*1.5}{0pt}


\usepackage{authblk}


\usepackage{graphicx}
\usepackage[space]{grffile}
\usepackage{latexsym}
\usepackage{textcomp}
\usepackage{longtable}
\usepackage{tabulary}
\usepackage{booktabs,array,multirow}
\usepackage{amsfonts,amsmath,amssymb}
\providecommand\citet{\cite}
\providecommand\citep{\cite}
\providecommand\citealt{\cite}
% You can conditionalize code for latexml or normal latex using this.
\newif\iflatexml\latexmlfalse
\providecommand{\tightlist}{\setlength{\itemsep}{0pt}\setlength{\parskip}{0pt}}%

\AtBeginDocument{\DeclareGraphicsExtensions{.pdf,.PDF,.eps,.EPS,.png,.PNG,.tif,.TIF,.jpg,.JPG,.jpeg,.JPEG}}

\usepackage[utf8]{inputenc}
\usepackage[english]{babel}



\usepackage{float}








\begin{document}

\title{Is loss of sense of smell a diagnostic marker in COVID-19: A Systematic
Review and Meta-analysis}



\author[1]{John Rocke}%
\author[2]{Claire Hopkins}%
\author[3]{Carl Philpott}%
\author[4]{B. Nirmal Kumar}%
\affil[1]{Royal Albert Edward Infirmary, Wigan}%
\affil[2]{University Hospital Lewisham}%
\affil[3]{University of East Anglia}%
\affil[4]{WWL NHS Trust}%


\vspace{-1em}



  
  \date{May 24, 2024}


\begingroup
\let\center\flushleft
\let\endcenter\endflushleft
\maketitle
\endgroup





\selectlanguage{english}
\begin{abstract}
Aims 1. To systematically review the currently available evidence
investigating the association between olfactory dysfunction (OD) and the
novel coronavirus (COVID-19). 2. To analyse the prevalence of OD in
patients who have tested positive on Polymerase Chain Reaction (PCR) for
COVID-19. 2. To perform a meta-analysis of patients presenting with
olfactory dysfunction, during the pandemic, and to investigate the
Positive Predictive Value for a COOVID-19 positive result in this
population. 3. To assess if olfactory dysfunction could be used as a
diagnostic marker for COVID-19 positivity and aid public health
approaches in tackling the current outbreak. Methods We systematically
searched MedLine (PubMed), Embase, Health Management Information
Consortium (HMIC), Medrxiv, the Cochrane Library, the Cochrane COVID-19
Study Register, NIHR Dissemination centre, Clinical Evidence, National
Health Service Evidence and the National Institute of Clinical
Excellence to identify the current published evidence which associates
coronaviridae or similar RNA viruses with anosmia. The initial search
identified 157 articles. 145 papers were excluded following application
of our exclusion criteria. The 12 remaining articles, that presented
evidence on the association between COVID-19 and olfactory dysfunction,
were critically analysed. Results OD has been shown to be the strongest
predictor of COVID-19 positivity when compared to other symptoms in
logistic regression analysis. In patients who had tested positive for
COVID-19 there was a prevalence of 62\% of OD. In populations of
patients who are currently reporting OD there is a positive predictive
value of 61\% for a positive COVID-19 result. Conclusion Our review has
shown that there is already significant evidence which demonstrates an
association between OD and the novel coronavirus -- COVID-19. It is
unclear if this finding is unique to this coronavirus as individual
viral phenotypes rarely present in such concentrated large numbers. We
have demonstrated that OD is comparatively more predictive for COVID-19
positivity compared to other associated symptoms. We recommend that
people who develop OD during the pandemic should be self-isolate and
this guidance should be adopted internationally to prevent transmission.%
\end{abstract}%



\sloppy


\emph{Disclosure Statement}

The authors declare that they have no relevant or material financial
interests that relate to the research described in this paper.

\emph{Data Sharing}

The data that support the findings of this study are available from the
corresponding author upon reasonable request.

\emph{Introduction}

There is already a wealth of anecdotal evidence that suggests that
olfactory dysfunction (OD) is an important symptom in patients who have
contracted the novel SARS-CoV-2 coronavirus (COVID-19). Initial reports
made in newspapers from Germany indicated that as many as two thirds of
cases of COVID-19 reported loss of smell whilst in South Korea, 15.3\%
of patients who have tested positive had perceived disturbance of smell
or taste . This is the first worldwide pandemic where reporting of
symptoms, aided by social media and telecommunication systems, has been
shared so widely. High profile public figures have reported both
symptoms which has led to increased interest and widespread interest in
the press and the public .

It has previously been demonstrated that the genetically similar
SARS-CoV virus can spread via a synapse-connected route to the medullary
cardiorespiratory centre. Coronaviral RNA has been identified post
mortem concentrated in the brain-stem of human patients during the
previous SARS-CoV pandemic, and studies in mice have shown that
previously described corona viruses can invade intracranially when
administered intranasally indicating that the virus may travel via the
olfactory nerves. Helms et al present a series of patients infected
during the current COVID-19 outbreak and demonstrate numerous
neurological sequelae and abnormalities on cross-sectional imaging of
the brain.

Brann et al (in a paper made available prior to peer review) have
identified non-neuronal cell types, such as sustentacular and olfactory
stem cells as well as horizontal basal cells are the potential target of
COVID-19 in the human olfactory epithelium via the ACE2 receptor and the
spike protein protease TMPRSS2. This presents three main theories for
potential loss of smell in COVID-19. Firstly, a local inflammatory
response affecting sensory function, secondly damage to support cells
and finally escalating damage to the architectural structure of the
entire olfactory epithelium, due to damage to sustentacular cells and
Bowman's glands .

Viral upper respiratory tract infection (URTI) is one of the known major
identifiable causes of olfactory dysfunction (OD) due to the
degeneration of olfactory epithelium . Due to the widespread and
insidious nature of viral URTI there is no data relating to the
incidence of post-viral OD for specific viruses but post-viral cases
typically account for 11\% of all cases of OD in the community with
cases presenting to specialist clinics typically representing 20\% of
cases . This group is often represented as a higher proportion in online
surveys and patient fora at around 30\% . Patients often present to the
Otolaryngologist in persistent cases but those that resolve soon after
the infective process has subsided are likely rarely reviewed or
reported .

BMJ best practice have recently published an update on Coronavirus and
the range of symptoms that are associated with this. They quote the
anecdotal evidence published by ENT UK and the American Academy of
Otolaryngology regarding the link between anosmia and coronavirus. Both
these international bodies have both recommended self-isolation for
patients who develop these symptoms . Despite lobbying by these
representative bodies OD has not been incorporated in to national or
international public health policy.

The aim of this systematic review and metanalysis is to identify the
currently available evidence for the relationship between COVID 19 and
self-reported loss of smell. This will include assessing the potential
for OD as a diagnostic marker in COVID-19, outlining the current
peer-reviewed evidence relating to this relationship and how it can be
utilised going forwards in clinical practice.

We decided to focus on OD and not include loss of taste in this review.
OD will lead to reduced retronasal olfaction and subsequently impact the
perception of taste in these patients. Flavour perception involves input
from ortho and retronasal olfaction and gustation, complemented by
trigeminal stimulation through touch and pain fibres. Patients typically
find it difficult to isolate true gustatory sensations from retronasal
olfaction without objective gustatory testing . Given the difficulties
in interpreting this symptom, in the absence of more detailed questions
regarding taste perception, we decided to solely review OD.

\emph{Methods}

We systematically searched MedLine (PubMed), Embase, the Health
Management Information Consortium (HMIC), Medrxiv, the Cochrane Library,
the Cochrane COVID-19 Study Register, NIHR Dissemination centre,
Clinical Evidence, National Health Service Evidence and the National
Institute of Clinical Excellence to identify the current published
evidence which associates coronaviridae or similar RNA viruses with
anosmia. The search strategy for Medline and Embase are demonstrated in
Appendix 1. The final search was undertaken in
18\textsuperscript{th}April 2020. We included all years and all
languages in the search.

The initial search identified 157 articles. 145 articles were excluded
as they did not investigate a link between the current coronavirus
outbreak and OD, were conference abstracts, isolated case reports or did
not have an English version available. The literature search is
presented in the Prisma flow diagram (image 1). One case series
presented loss of smell and taste in combination, where patients were
included if they had experienced either symptom. As such we were unable
to isolate olfactory dysfunction in their population. Reporting related
but independent symptoms in this way prevents formal analysis of their
individual epidemiological factors and impact on patient outcomes.

We used the ROBINS-E (Risk of Bias in Non-randomised Studies -- of
Exposures) tool to assess the studies for bias. The articles were
assessed across 7 parameters; confounding factors, selection of
participants, classification of exposures, departures from intended
exposures, missing data, measurement of outcomes and the reported
result. All the studies were assessed at ``serious'' risk of bias due
these common themes; lack of adjustment for confounding variables,
differences in follow up and the start of exposure, variation in
reporting, and numerous different subgroups reported.

\emph{Results}

\textbf{1. Methodology}

There were 12 articles that have investigated the association between
COVID-19 and OD. The studies vary in their methodology and in the
patient populations that they target. A summary of the studies
evaluated, their study methodology and the quality of the evidence is
presented below in Table 1. Several of the studies had not completed the
peer review process and this status is also demonstrated in the table.

\textbf{Table 1}

\textbf{2. Description of studies}

\textbf{2.1 Cross-sectional Questionnaire}

The most common methodology for assessment in the articles searched was
a cross-sectional questionnaire which were conducted over a variety of
mediums i.e. face to face, mobile application or web-based forms. The
cohort of patients targeted also varied between inpatient and outpatient
populations and in their geographical location (Tables 2 and 3). Whilst
there are clear limitations to this approach and it is not possible to
demonstrate a direct causal relationship between COVID-19 and OD but
they are able to present associations in the symptomology of this
pandemic.

\textbf{2.2 Case Series}

The majority of the remaining studies present case series. They present
similar cross-sectional evidence to the questionnaire designed studies
with a common aim of investigating the symptomology of anosmia in the
COVID-19 era. This approach should contribute to limiting the level of
bias in their results when compared to an outcome-based case series but
they are similarly only able to demonstrate association and not causal
effect. The complementary data output, between the questionnaire and
case-series approaches, allows us to compare the two approaches
concurrently in a meta-analysis.

\textbf{2.3 Search Term Analysis}

Walker et al were unique in their approach and used Google Trends to
track search terms related to loss of smell. They demonstrate
statistically significant association of the Google search terms and the
incidence COVID-19 cases and deaths. The previous figures for the same
time period in 2019 and the H1N1 pandemic were used as controls. This
correlation was present across numerous countries including Italy,
Spain, the United Kingdom (UK), the United States of America (USA),
Germany, France, Iran and the Netherlands. They propose that this data
could be used to track disease hot spots internationally where targeted
control measures could then be implemented. For this to be effective
there needs to be clear data on the positive predictive value of new
onset anosmia and COVID-19 positivity .

\textbf{2.4 Case Control Study}

In the only study so far to institute validated quantitative olfactory
testing Moein et al, in Iran, evaluated 60 patients who had tested
positive for COVID-19. Their control group were selected from a group of
141 controls from a previously conducted study. They handpicked age and
sex matched individuals from this cohort in an attempt to mirror their
COVID-19 positive group. COVID-19 patients completed the Persian version
of the 40-odorant University of Pennsylvania Smell Identification Test
(UPSIT) assisted by a trained examiner, they do not explain how they
administered the test in their previously investigated control group.
Ninety-eight percent of their COVID-19 group had some level of OD with
25\% of these subjects being completely anosmic. There was a
statistically significant reduction in scores, in all 40 stimuli, within
the COVID-19 group. There were no differences in demographics between
the two groups but the way the control group was matched will have
affected this data .

\textbf{3 Risk of Bias and Limitations}

When analysing data related to COVID-19 positivity it is important to
recognise the sensitivity of the test is variable. Bronchoalveolar
lavage is the most sensitive test (93\%) whilst nasal swabs (63\%) and
pharyngeal swabs (46\%) have lower positive rates\textsuperscript{14}.
Moein et al, who conducted the UPSIT, case control study and Mao et al
were the only authors to report the technique and anatomical location of
their Polymerase Chain Reaction (PCR) analysis of COVID-19 status. Moien
et al used nasal aspirates or washes and Mao et al's group used throat
swabs . Due to the relatively low sensitivity of the test used there
will be a proportion of false negatives that will falsely lower the
incidence of COVID-19 positivity in the OD groups.

The majority of the responses to questionnaires were received using
remotely using electronic response forms of mobile based applications
which will cause selection bias. Younger more technologically
interactive cohort are more likely to interact and this sub-group seem
to be less affected by COVID-19 when compared to older age groups who
have a higher morbidity and mortality. For example, Menni et al(in an
unpublished paper made available before peer review) who used a mobile
based application, report an average age of 41.48 (CI = 13.77) for those
in their non-PCR-tested group, including over 1.5million people.
Hospitalised populations are also less likely to interact with these
methods due to their disease severity, internet connection or associated
interventional treatments.

Cross-sectional questionnaires and case series are prone to bias due to
influence of confounding variables, assessment of patients at different
time points relative to their exposure and reporting bias. In case
series specifically consecutive patients often missed in data
collection. In these studies, however the researchers are simply
presenting patient factors and associated symptoms rather than
treatments or interventions and their subsequent effects or outcomes and
this observational nature could help to reduce observer bias. In studies
that were conducted requiring historical data from the patients there is
a risk of recall bias and under-reporting or inaccuracies of symptoms
specifically where onset and duration of symptoms is involved.

\textbf{4. Comparing COVID positive and Olfactory Dysfunction
Populations}

Two distinct populations have assessed in the literature. The first
group were those patients who had received testing and were confirmed
positive COVID19 patients, the prevalence of OD was then analysed. The
second were people who had experienced OD and the prevalence of COVID19
within this cohort. Menni et al and Yan et al report data from both
groups concurrently and presented data for both populations in their
results .

\textbf{4.1 Prevalence of Olfactory Dysfunction in COVID-19 Positive
Patients}

Menni et al (in an unpublished paper made available before peer review)
used the ``COVID RADAR'' symptom tracker app to extract a cohort of
patients who had tested positive for COVID-19 and their associated
symptomology. Over 1.5million people reported symptoms on this app but
just 1702, who answered questions of loss of smell (and taste), were
tested and 579 subsequently tested positive. This small proportion of
their total population was the main limitation of this study. They then
analysed the COVID-19 positive and negative groups for prevalence of
symptoms. In the COVID-19 positive group 59.41\% had experienced loss of
smell compared to 18.97\% in the negative group. For patients reporting
loss of smell they report an odds ratio of 6.59 for a positive COVID-19
when compared to a negative result. They also analyse the impact of
other independent symptoms, other than loss of smell (and taste),
adjusting for age, sex and Body Mass Index (BMI). In their model loss of
smell and taste was the strongest predictor of a COVID-19 positive
result .

Lechian et al's multi-centre study analysed patient and volunteer health
care professionals' who had a PCR positive result for COVID-19 with a
questionnaire. Patients in the intensive care unit, patients with
previous OD and those without a COVID-19 PCR result were excluded from
analysis. The impact of OD was evaluated using a quality of life tool
(sQOD-NS). 85.6\% of their cohort of 417 patients reported OD. The
majority self-rated as anosmic (79.6\%) but others experienced hyposmia,
phantosmia and parosmia. Anosmic patients were found to have a
significantly lower sQOD-NS score compared with the hyposmic and
normosmic individuals. This OD was not significantly associated with
rhinorrhoea or nasal obstruction but a significant association was found
with females being proportionally more affected than males. In the
subgroup of patients who had clinically resolved infection the OD
persisted in 63\% of cases .

Yan et al sent an email invitation to complete a survey to 1480 patients
who had undergone COVID-19 testing. They had a 58\% response from
COVID-19 positive patients and a 15\% response from the negative group.
Their survey evaluated patient reported symptoms with a focus on smell
and taste. Sixty-eight percent of the COVIVD-19 positive group reported
OD and similarly to Menni et al they found that loss of sense of smell
(and taste) showed the largest magnitudes of association to COVID-19
positivity when compared with other symptoms. Seventy-two percent of the
COVID-19 positive patients with OD reported improvement at the time of
the survey .

Mao et al were one of the first groups to present the symptomology of
patients presenting with a positive COVID-19 swab result. 5.1\% of this
group of 214 patients had experienced hyposmia. This was a retrospective
analysis of electronic patient data and as such there is a risk that OD
was not a symptom explored or documented in individual consultations
within this cohort of patients. According to a ``diagnostic criteria''
that is not described they divided their patients in to severe and
non-severe groups. Of the 11 patients who had reported hyposmia 3 were
non-severe and 8 were severe .

Giacomelli et al interviewed 59 of 88 inpatients with COVID-19
demonstrated on PCR, there were 29 non-respondents due to receiving
ventilation, dementia and linguistic barriers. They report combined
rates of smell or taste disturbance and as such comparative incidence
rates solely for OD was not possible to produce from the data presented.
In their cohort the olfactory and gustatory disorders occurred in
proportionally younger and more commonly female subjects and no patients
had recovered at the time of interview. No data relating to time of
interview following onset of symptoms is reported .

In the studies that investigated olfactory symptoms independently we
present the prevalence rates in Table 2 to form a meta-analysis for the
prevalence of OD in the population of patients that have tested
positive.

\textbf{Table 2}

\textbf{4.2 Prevalence of COVID-19 in New Onset Olfactory Dysfunction
Cohorts}

Due to the differences in public health approaches and the availability
of testing it is difficult to demonstrate clear associations between new
onset OD and COVID-19 positivity. There were however three studies that
did have PCR results for patients presenting with OD since the start of
the COVID-19 pandemic. In table 2 we demonstrate that there is a high
prevalence of COVID-19 positivity in patients currently presenting with
OD.

The American Academy of Otolaryngology -- Head and Neck Surgery
(AAO-HNS) developed a COVID-19 Anosmia reporting tool for clinicians.
Responses were collected from clinicians around the world relating to
the association of COVID-19 and anosmia. They do not clearly state if
all submitted patients had PCR testing performed. 237 entries were
analysed; anosmia was the initial symptom in more than 25\% of cases,
27\% had noticed some improvement and in 40\% was the symptom that led
to a test being performed .

Bagheri et al conducted a widely completed online survey (in an
unpublished paper made available before peer review), of the general
population in Iran, to identify patients with OD since the inception of
the outbreak in their country. They demonstrated high numbers of people
who had experienced OD in their cohort. Their respondents were commonly
female (71\%) and experienced sudden onset in their OD (76\%). Only
1.1\% were admitted to hospital for treatment indicating a largely mild
disease when OD was experienced. In a similar online questionnaire
study, conducted in the UK, by Hopkins et al the demographic features
were replicated. The majority of this British population with OD
reported complete loss of smell (74.4\%) and in 16\% of cases it was
their only symptom. A proportion of these patients did report receiving
a PCR test with a 74\% positive rate in this sub-group .

Gane et al present a case series of 11 patients presenting with sudden
onset anosmia during the epidemic in the United Kingdom. In 5 of these
patients it was an isolated symptom and just one of these patients were
self-isolating . Gengler et al present findings (in an unpublished paper
made available before peer review) from a French case series, not
currently published, which demonstrated a positive COVID-19 nasal PCR
swab in 94\% of their 55-patient series .

Table 3 demonstrates the average ages and gender proportions of the six
studies with OD cohorts.

\textbf{Table 3}

\emph{Conclusion}

Our review has shown that there is already significant evidence which
demonstrates an association between OD and the novel coronavirus --
COVID-19. It is unclear if this finding is unique to this coronavirus as
individual viral phenotypes rarely present in such concentrated large
numbers. Classically patients present with persistent symptoms following
a viral illness many weeks or months after. The symptomology during the
infective phase of the virus has not previously been studied and
therefore it is not possible to draw direct comparison between other
similar viruses. Walker et al have however demonstrated trends between
increasing cases of COVID-19 and the increase in positive novel
coronavirus cases that was not mirrored during the previous H1N1
pandemic in 2009 .

Due to the rapid spread of COVID-19 in this pandemic it is
understandable that there are a lack of studies using objective measures
and rigorous controls. The most common methodologies used were
cross-sectional questionnaires and case series. These approaches are at
risk of bias and we can only discuss associations as a result. Further
research will be required to demonstrate clearer links between OD and
COVID-19 going forwards.

In the meta-analysis of studies with cohorts of patients who had a
positive PCR test the prevalence of OD was 62\%. Both Menni et al and
Yan et al compared OD to other associated symptoms seen in COVID-19 such
as fever, cough, fatigue, dyspnoea and diarrhoea. They both found that
OD was the strongest predictor of a positive PCR result for COVID-19
when compared to the other symptoms when applying their logistic
regression analysis . It is worth noting that the current self-isolation
advice, released by Public Health England, only applies to people
experiencing a new continuous cough and/or a high temperature .

When we looked at patients who had experienced OD during the outbreak
there were several studies that demonstrated an increase in the
prevalence of loss of smell in their populations when compared to
previous estimates . The largest data sets, conducted predominantly in
the outpatient setting, by Hopkins and Bagheri et al indicated a female
preponderance in their cohorts (73\% and 71\% respectively). These two
studies also demonstrated an average affected age between 30-40. It has
been demonstrated that both advanced age and the male sex are risk
factors for the severe form of the disease and an increased rate of
mortality . It could be that this cohort of patients were not targeted
by this study due to the more elderly populations not interacting with
web-based surveys or being within the inpatient population due to their
disease severity. Moein et al demonstrated in their study of inpatients
that OD was a common finding in this population too when they applied
objective UPSIT testing to confirmed cases . Further research is needed
to identify if the incidence of OD varies between different ages and
genders and as such if particular disease phenotypes for COVID-19 can
give clinicians prognostic information.

In areas where testing has not been adopted widely tracking of this OD
could be vital in identifying hot-spots where population-based
management strategies can then be targeted. Tracking OD using
mobile-based applications, such as the one developed by Menni et al,
will allow real time data tracking for aid models in the prediction of
national or regional COVID-19 cases . This approach could lead to
specific social distancing measures being implemented in areas where OD
is wide-spread and will also help in modelling when these measures could
be relaxed as most patients seem to recover their sense of smell
following the illness.

Given the growing evidence to support an association between OD and
COVID-19 it is paramount that national and international health bodies
recognise this association. The World Health Organisation and national
public health bodies have not yet accepted this link and as such
patients with OD are not self-isolating. We have demonstrated that OD
can be the first symptom to arise, and in some cases, may be the only
symptom(s) that patients experience. We recommend that people who
develop OD during the pandemic should be self-isolating and this
guidance should be adopted internationally to prevent transmission.

\textbf{References}

\textbf{Hosted file}

\verb`Table 1 Anosmia OD in COVID 19.docx`  available at \url{https://authorea.com/users/314081/articles/444472-is-loss-of-sense-of-smell-a-diagnostic-marker-in-covid-19-a-systematic-review-and-meta-analysis}

\textbf{Hosted file}

\verb`Table 2 Anosmia OD in COVID 19.docx`  available at \url{https://authorea.com/users/314081/articles/444472-is-loss-of-sense-of-smell-a-diagnostic-marker-in-covid-19-a-systematic-review-and-meta-analysis}

\textbf{Hosted file}

\verb`Table 3 Anosmia OD in COVID 19.docx`  available at \url{https://authorea.com/users/314081/articles/444472-is-loss-of-sense-of-smell-a-diagnostic-marker-in-covid-19-a-systematic-review-and-meta-analysis}

\textbf{Hosted file}

\verb`Prisma Flow Diagram SR Anosmia COVID19.doc`  available at \url{https://authorea.com/users/314081/articles/444472-is-loss-of-sense-of-smell-a-diagnostic-marker-in-covid-19-a-systematic-review-and-meta-analysis}

\selectlanguage{english}
\FloatBarrier
\end{document}

