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2 PATHOGENS PROVOKING MOST DEATHS WORLDWIDE BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS
Hessling, Feiertag and Hoenes
decade caused by effective sanitary and medical meas-
ures like vaccination programs, the worldwide situation
and therefore the death statistics underwent distinct
alteration. Another reason is the large amount of exist-
ing data that impedes the possibility to simply gather an
overview. Lastly the data provided by different organi-
zations within the last few years seems to be slightly
contradictory. The numbers of the UN / Unesco (United
Nations, 2013) give the impression that every 20 sec-
onds a child below 5 years dies of diarrhea caused by
contaminated water which would result in almost 1.6
million dead children per year and would make diarrhea
the globally most important disease. In another word-
ing UN Secretary General Ban Ki-moon talked about
more than 800 000 children annually dying of diarrhea
(UN Secretary-General, 2013)which would still make it
the most important disease at least for children below
5 years.
These numbers, that can be found in of cial bro-
chures and speeches, are dif cult to retrace and they are
in contrast to lower values in the Global Burden Disease
study 2010 (Liu et al., 2012) and the even more lower
numbers in the Global Burden Disease studies of 2013
(Murray et al., 2015) and 2015 (Wang et al., 2016a). This
mentioned GBD 2015 study is not only newest but it is
also much more detailed and better documented than
the UN documents and has passed quality criteria like
peer review processes. In conclusion the GBD 2015 study
is most probably the most reliable data source on causes
of death for infections and other diseases.
Due to enhanced medical treatment, including vacci-
nation and improved sanitation and drinking water sup-
ply the number of casualties – published in the different
Global Disease Studies - has fortunately decreased for
many causes of death within the last decade. To con-
tinue this positive development more information on
the causes of death would be helpful. Concerning dis-
eases this means identifying the provoking pathogens.
For some infections caused by a known single micro-
organism this does not represent a problem, but among
the most important illnesses like diarrhea and lower
respiratory tract infections there are many potential
pathogens generating similar symptoms and sometimes
even co-infections caused by more than one pathogen
occur.
The importance of this knowledge is self-evident
for medical treatment like the prescription of antibiot-
ics. But it is also crucial for technical developments like
the application of UV-C water disinfection for diarrhea
prevention in the Developing Countries, one of the top-
ics of our working group (Hessling et al., 2016). Diar-
rhea could be provoked by bacteria like Vibrio cholera
or Escherichia coli or viruses like rotavirus or adeno-
virus. To reduce the concentration of Vibrio cholerae
by three orders of magnitude a UV-C irradiation dose
of about 2.2 J/cm
2
would be necessary. To achieve the
same result for Escherichia coli 5 – 10 J/cm
2
are required
and for rotavirus or adenovirus it would be even25 J/
cm
2
and 100 J/cm
2
, respectively (Chevre ls and Caron,
2006). This clearly shows that not only medication but
also technical developments would actually bene t from
knowing the most important pathogens.
MATERIAL AND METHODS
The imaginable approach to create a listing of pathogens
and their number of global casualties by looking for all
known pathogens and count the deaths they provoked
is almost impossible because of two reasons: 1.) There
is the large number of 1400 known human pathogenic
species (Nature Reviews Microbiology, 2011) and 2.)
information on the number of deaths doesn´t globally
exist for most of them.
Fortunately there is the Global Burden Disease Study
2015 with information on the world wide health situa-
tion compiled, evaluated and analyzed by a large num-
ber of experts. Among the provided data are statistics
on the global numbers of deaths caused by different dis-
eases (Wang et al., 2016a). The values are rather estima-
tions than exact indications but nevertheless probably
the most accurate, current available numbers and there-
fore they are taken as xed basis for this investigation.
As far as necessary and possible missing data is sup-
plemented by studies published within the last 10 years.
In a rst step all diseases mentioned in (Wang et al.,
2016a), that are provoked by at least one pathogen are
identi ed and in a second step the responsible patho-
gens and their assumed share of casualties is elaborated
(Table 1). This is not always straight forward, because
of complications like incomplete data and due to co-
infections by more than one pathogen.
TUBERCULOSIS AND AIDS
Tuberculosis and AIDS are among the most widespread
infectious diseases with loss of life result. Tuberculosis
is caused by Mycobacterium tuberculosis and is respon-
sible for more than 1.1 million deaths in 2015. AIDS
claimed almost 1.2 million casualties in the same period
(Wang et al., 2016a), but the explicit assignment to a
speci c pathogen is somewhat more complex compared
to Tuberculosis. AIDS is provoked by the HI-virus but
the patients die because of co-infections like tubercu-
losis or pneumoniae or other diseases. Nevertheless the
GBD 2015 study assigns these casualties to AIDS and
this procedure is continued here, wherefore these deaths
are assigned to the HI-virus.