In e na ional Jou nal o
En i onmen al Resea ch
and Public Heal h
A icle
The Iden i ica ion o Scien i ic Communi ies and
Thei App oach o Wo ldwide Mala ia Resea ch
JoséAn onio Ga ido-Ca denas 1, F ancisco Manzano-Aguglia o 2,* , Lilia González-Ce ón3,
F ancisco Gil-Mon oya 2, Al edo Alcayde-Ga cia 2, Nu ia No as 2
and Concepción Mesa-Valle 1
1Depa men o Biology and Geology, Uni e si y o Alme ia, 04120 Alme ia, Spain;
[email p o ec ed] (J.A.G.-C.); [email p o ec ed] (C.M.-V.)
2Depa men o Enginee ing, Uni e si y o Alme ia, CeiA3. 04120 Alme ia, Spain; [email p o ec ed] (F.G.-M.);
[email p o ec ed] (A.A.-G.); [email p o ec ed] (N.N.)
3Regional Cen e o Public Heal h Resea ch, Na ional Ins i u e o Public Heal h,
Tapachula 30700, Chiapas, Mexico; [email p o ec ed]
*Co espondence: [email p o ec ed]; Tel.: +34-9500-15693
Recei ed: 4 No embe 2018; Accep ed: 28 No embe 2018; Published: 30 No embe 2018
Abs ac :
I is essen ial o es ablish a pa e n o de ec he s eng hs and weaknesses o wo king
g oups publishing on mala ia, o p omo e coo dina ion o acili a e he e adica ion o he disease.
Gi en he complexi y o he scien i ic ne wo k o g oups and ins i u ions s udying mala ia, i is
necessa y o use a ma hema ical algo i hm ha allows us o know he eal s uc u e o esea ch on he
disease in he wo ld. In his wo k, a icles wi h he wo d “mala ia” in he i le o au ho keywo ds
ga he ed om Else ie Scopus da abase we e analyzed. By means o speci ic so wa e, g aphs we e
c ea ed. The analysis o he da a allowed es ablished di e en scien i ic communi ies, among which
wo we e e y di e se: one o med by hose g oups conce ned abou he ec o ansmission and
con ol, and ano he one ocused on he d ug esis ance o he pa asi e. Basic, applied, and ope a ional
esea ch o e adica e mala ia is an ambi ious goal o he in e na ional ins i u ions and he scien i ic
communi y. The combina ion o e o and he es ablishmen o a wo ldwide-scien i ic ne wo k ha
allows an e ec i e in e connec ion (exchange) o knowledge, in as uc u e echnology, collabo a o s,
inancial esou ces, and da ase s will con ibu e mo e e ec i ely o end he disease.
Keywo ds: mala ia; ec o ; d ug esis ance; scien i ic communi y
1. In oduc ion
Mala ia is one o he in ec ious diseases ha gene a es he g ea es conce n o global heal h [
1
,
2
].
Acco ding o he las epo o he Wo ld Heal h O ganiza ion, in 2016, mala ia p oduced almos hal a
million dea hs and mo e han 200 million cases we e es ima ed, wi h 90% o hese cases occu ing in
A ican coun ies. Mala ia is a mosqui o-bo ne disease caused by a pa asi e o he genus Plasmodium,
wi h six species ha a ec humans: Plasmodium alcipa um, which causes he mos dea hs, Plasmodium
i ax, he mos widely sp ead excep in sub-Saha an A ica, Plasmodium mala iae,Plasmodium knowlesi,
Plasmosdium o ale cu isi, and Plasmodium o ale wallike i [3–6].
Plasmodium has a complex li e cycle, de eloping pa ially in mosqui oes o he genus Anopheles [
7
].
In humans, he pa asi e has a mul iplica i e exoe y h ocy ic s age, in hepa ic cells, and ano he
in ae y h ocy ic phase. The beginning o he cycle occu s wi h he bi e o an in ec ed emale Anopheles
mosqui o, which inocula es he spo ozoi es in he e eb a e hos . These mig a e o hepa ic cells,
whe e hey mul iply and ans o m in o exoe y h ocy ic me ozoi es ha in ade ed blood cells again,
gene a ing e y h ocy ic me ozoi es ha can in ade new ed blood cells and gene a e a new ba ch o
In . J. En i on. Res. Public Heal h 2018,15, 2703; doi:10.3390/ije ph15122703 www.mdpi.com/jou nal/ije ph
In . J. En i on. Res. Public Heal h 2018,15, 2703 2 o 14
me ozoi es o de eloped in o game ocy es. Game ocy es will be inges ed when Anopheles emales
bi e he hos o eed on hei blood. In P. i ax and P. o ale, he hepa ic schizon can emain do man
ha bo ing hypnozoi es ha can be eac i a ed yea s la e .
The mala ia pa asi e is also gene ically complex [
8
]. Howe e , he cu en molecula ools make
he analysis o gene ic ma e ial a ailable o p oduce da a o g ea in e es . The sea ch o genes
associa ed wi h d ug esis ance o pheno ypes ela ed o clinical mani es a ions o high pa hogenici y,
a e wo undamen al aspec s add essed a a molecula le el in mala ia esea ch. The nuclea genome
o P. alcipa um was sequenced in 2002 [
6
], and, la e , he comple e genomes o he es o he human
Plasmodium we e ob ained. These genomes ha e a size anged om 23.3 o 33.6 Mb, o ganized in o
14 ch omosomes wi h a numbe o genes anging om 5507 in P. alcipa um o 7132 in P. o ale cu isi.
In addi ion, Plasmodium pa asi es con ain wo mo e genomes. A mi ochond ial genome, wi h he
genes Cox1, Cox3 and Cy b [
9
], and an apicoplas genome, wi h genes ela ed o he syn hesis o a y
acids [10].
One o he mos ambi ious goals in cu en esea ch on mala ia is he sea ch o a accine agains
he disease [
11
]. Bu , as al eady men ioned, he complex biology, genome, and li e cycle o he
pa asi e, as well as i s abili y o e ade he p o ec i e immune esponses o he hos , ha e made he
sea ch unsuccess ul. The design o mala ia accines is e y b oad and a ied. Cu en ly, esea che s
a e wo king wi h accines ha ac a di e en poin s in he Plasmodium li e cycle. On he o he
hand, accines a e being de eloped agains a speci ic an igen, as well as accines agains se e al
an igens a di e en s ages o he pa asi e li ecycle (mul i-s a e accines), o e en h ough he use o
comple e spo ozoi es. The use o i al ec o s in he e ologous p ime-boos egimens ep esen ano he
in e es ing al e na i e o he de elopmen o an e ec i e accine. They a e all he nex -gene a ion o
mala ia accines [
12
,
13
]. O he s a egies being add essed in he igh agains mala ia ocus on he use
o mosqui o ne s and epellen s o y o a oid mosqui o bi es [14].
The analysis o mala ia esea ch is an excessi ely complex sys em o ca y ou wi h a simple
me hodology. Bu , like o he complex sys ems, i has a s uc u e in scien i ic communi ies (SC), whose
app oach acili a es analysis [
15
]. The communi y de ec ion is an issue ha has been unde s udy by
he scien i ic communi y o a long ime [
16
]. I is based on he sea ch o subs uc u es o communi ies
ha bes ep esen he ne wo k’s opological ea u es [
17
]. To ob ain hese subs uc u es, i is common
o use op imiza ion echniques ha combine he nodes in such a way ha a ce ain objec i e unc ion
is maximized o minimized. In his ega d, he modula i y unc ion has been success ully used by he
scien i ic communi y o ob ain a good de ini ion o opologically ela ed subs uc u es. Modula i y
was p oposed by Newman [
18
] and measu es he quali y o he clus e o nodes. The highe he alue,
he mo e p ecise he de ini ion o he de ec ed communi y s uc u e. Since he in en ion o modula i y,
cons an imp o emen s ha e been gene a ed [
19
] gi ing ise o one o he bes -known algo i hms:
Gi an–Newman (GN), which is an algo i hm based on a di isi e me hod. This me hodology has
al eady been used success ully in many s udies [
20
,
21
] and i is a e y use ul ool in bibliome ic
s udies [
22
,
23
]. Thus, communi ies o clus e s a e gene ally g oups o nodes ha a e mo e likely o be
connec ed o each o he han o membe s o o he g oups o o he es o he ne wo k [
24
], in pa icula
in bibliome ic s udies he scien i ic ela ions be ween g oups o coun ies ha e been de ec ed, o he
opics a ound which a ce ain ield o esea ch is clus e ed [
25
,
26
]. Communi ies, in complex sys ems,
can be de ined as g oups o nodes o a ne wo k, in which each node is densely connec ed wi h many
o he nodes in he ne wo k. The de ec ion o communi ies is based on he p inciple ha he nodes
belonging o he same communi y a e mo e likely o in e ac wi h each o he . Tha is, hey ha e g ea e
connec i i y. In his a icle, he au ho s in oduce he no el y o using communi y de ec ion o ind SC
associa ed wi h mala ia esea ch. This new app oach will make i possible o es ablish u u e ac ion
policies in o de o de ini i ely e adica e mala ia.
In . J. En i on. Res. Public Heal h 2018,15, 2703 3 o 14
2. Ma e ials and Me hods
The wo la ge scien i ic da abases, Web o Science (WoS) and Scopus, aise he majo issue o
compa ison and consis ency o he s a is ics de i ed om di e en da a sou ces [
27
]. Va ious esea ch
s udies ha e assessed he supe posi ion be ween bo h, concluding ha hey a e simila when he
co e age since 1996 is es ic ed (Scopus co e age) [
28
,
29
]. Rega ding he jou nals epo ed in he wo
la ge scien i ic da abases such as Web o Science (WoS) and Scopus, a compa a i e analysis shows
ha he ange o jou nals in WoS (13,605 jou nals) is smalle han ha o Scopus (20,346 jou nals) [
30
],
and he ela ionships be ween he esul s ob ained wi h bo h da abases o he numbe o a icles
and he numbe o ci a ions ob ained by coun ies, as well as o hei ankings, a e ex emely s ong
(
R2≈0.99
) [
31
]. The e o e, only Scopus da a ha e been used. This me hodology has been used wi h
success in di e en scien i ic ields [32–35].
A so wa e has been p og ammed o he massi e download o da a om Scopus using he
de elope applica ion ha allows his da abase. The SW can be di ided in o ou unc ional blocks as
desc ibed below, see Figu e 1:
1.
S a Module. Which equi es as inpu he desi ed sea ch c i e ia, o example: TITLE (“mala ia”)
OR AUTHKEY (“mala ia”) OR ABS (mala ia), once he c i e ia is selec ed, he ime ange o
he sea ch is equi ed and a lis o SCOPUS apikeys needed o use he Scopus sea ch se ice
(h ps://de .else ie .com/). The ou pu (da a iles in json o ma con aining he same da a as
when sea ching he web, wi h he di e ence ha one ile is ob ained o e e y 25 sea ch esul s)
is he inpu o he nex module o he applica ion. I is wo h highligh ing he la ge olume o
da a iles gene a ed o a sea ch c i e ion such as he one men ioned abo e.
2. Da a p ocessing. In his second s age, each one o he esul s ob ained in he p e ious phase a e
analyzed, ob aining as ou pu : a single lis o he Scopus-ID o au ho s and a lis o he DOIs o
he a icles.
3.
Da a collec ion. In his s age, wo h eads o wo k a e launched in pa allel: one ha o e sees
downloading all he in o ma ion o he au ho s o each one o he Scopus-ID o he lis , gene a ing
a leas one ile pe au ho ; and ano he ha will download all he in o ma ion o he a icles
o each one o he DOIs o he lis o pape s. The e o e, a di ec o y o au ho s and ano he o
a icles whe e all he men ioned in o ma ion will be s o ed is ob ained as ou pu .
4.
Es ablishing ela ionships. This module, like he p e ious one, is compu a ionally mo e expensi e
and is subdi ided in wo: one o he analysis o he au ho s and he o he o he analysis o
he a icles.
a.
Au ho s collec ion. This submodule ex ac s all ele an in o ma ion abou he au ho s:
H-Index, Name, A ilia ion, Na ion, e c. On he o he hand, collabo a ions be ween au ho s
a e sough , o his pu pose each au ho is examined, which a e hei a icles, ex ac ing all
he au ho s om he pape s o an au ho , es ablishing a bidi ec ional ela ionship be ween
he au ho and he co-au ho s.
b.
Pape s collec ion. In his h ead we ob ain in o ma ion abou he a icles, Keys, au ho s,
co-au ho s, e e ences o o he pape s, e c. Fo each pape we ob ain a unidi ec ional
ela ionship wi h he pape ha ci es, hus gene a ing he ne wo k o he g aph.
In . J. En i on. Res. Public Heal h 2018,15, 2703 4 o 14
In . J. En i on. Res. Public Heal h 2018, 15, x 4 o 14
Figu e 1. Me hodology lowcha
The Else ie Scopus da abase was used o ob ain in o ma ion abou published wo ks on mala ia.
A comple e sea ch was pe o med using he sea ch que y: (TITLE-ABS-AUTHKEY (mala ia)). The
sea ch ange used was om 1900 o 2017. I should be no ed ha a di e en sea ch que y can gi e
di e en esul s. To acili a e he analysis o he da a, a powe ul ne wo k analysis ool, Gephi, was
used. The da a ex ac ion was ca ied ou au oma ically h ough he implemen a ion o a speci ic
so wa e called Resea ch Ne wo k Bo (ResNe Bo ) [36]. This so wa e allows he elabo a ion o a
g aph in which each publica ion on mala ia is ep esen ed by a node, and he connec ions be ween
wo nodes ep esen he exis ence o a ci a ion o one a icle on he o he . Wi h hese da a, a new
g aphic is cons uc ed. This ime, he nodes ep esen he esea che s, while he ela ionships
be ween he nodes ep esen he collabo a ions in a leas one publica ion. Da a ob ained h ough
ResNe Bo was e ined wi h he OpenRe ine so wa e (OR) ( o me ly Google Re ine) (Google,
Moun ain View, Cali o nia, USA) and o ganized in o sp eadshee s o acili a e i s managemen . The
need o use OR is jus i ied by he ac ha au ho s o en w i e sligh ly di e en keywo ds ha iden i y
he same concep s. In o de o be able o uni y hese keywo ds OR is used because i p o ides he
necessa y mechanisms o ind and me ge w i en a ia ions o he same wo d. E.g. “New Yo k”,
“New-Yo k”, “new yo k”, e c. So, in ou esea ch he keywo ds need o be e ined.
3. Resul s
3.1. E olu ion o Scien i ic Ou pu
The sea ch yielded 85,370 esul s, whose g ow h is ep esen ed in Figu e 2. As can be obse ed,
he da a show wo ends. The i s o hem ex ends h oughou he wen ie h cen u y, and i is
exponen ial, while he second one is om he yea 2000 o he p esen , and i is linea . In he i s o
he pe iods, he adjus men o he end line is op imal, gi ing ise o a eg ession coe icien R2
g ea e han 0.9. The only da a ha sepa a es om his end line co esponds o he numbe o
a icles published in he yea 1946, which is 429. This da a is abno mally high. In ac , i is no eached
and exceeded comple ely un il he 1980s. The explana ion o his is ound in wo miles ones o g ea
impo ance in he igh agains mala ia ha ook place in ha yea . On he one hand, chlo oquine
was ecognized and es ablished as an e ec i e and sa e an imala ial agen [37]. And, on he o he
hand, he CDC (Communicable Disease Cen e ) was c ea ed om he O ice o MCMA (Mala ia
Con ol in Wa A eas), whose main objec i e was o igh agains diseases such as mala ia in he
Figu e 1. Me hodology lowcha .
The Else ie Scopus da abase was used o ob ain in o ma ion abou published wo ks on mala ia.
A comple e sea ch was pe o med using he sea ch que y: (TITLE-ABS-AUTHKEY (mala ia)).
The sea ch ange used was om 1900 o 2017. I should be no ed ha a di e en sea ch que y
can gi e di e en esul s. To acili a e he analysis o he da a, a powe ul ne wo k analysis ool, Gephi,
was used. The da a ex ac ion was ca ied ou au oma ically h ough he implemen a ion o a speci ic
so wa e called Resea ch Ne wo k Bo (ResNe Bo ) [
36
]. This so wa e allows he elabo a ion o a
g aph in which each publica ion on mala ia is ep esen ed by a node, and he connec ions be ween wo
nodes ep esen he exis ence o a ci a ion o one a icle on he o he . Wi h hese da a, a new g aphic is
cons uc ed. This ime, he nodes ep esen he esea che s, while he ela ionships be ween he nodes
ep esen he collabo a ions in a leas one publica ion. Da a ob ained h ough ResNe Bo was e ined
wi h he OpenRe ine so wa e (OR) ( o me ly Google Re ine) (Google, Moun ain View, CA, USA) and
o ganized in o sp eadshee s o acili a e i s managemen . The need o use OR is jus i ied by he ac
ha au ho s o en w i e sligh ly di e en keywo ds ha iden i y he same concep s. In o de o be
able o uni y hese keywo ds OR is used because i p o ides he necessa y mechanisms o ind and
me ge w i en a ia ions o he same wo d. E.g., “New Yo k”, “New-Yo k”, “new yo k”, e c. So, in ou
esea ch he keywo ds need o be e ined.
3. Resul s
3.1. E olu ion o Scien i ic Ou pu
The sea ch yielded 85,370 esul s, whose g ow h is ep esen ed in Figu e 2. As can be obse ed,
he da a show wo ends. The i s o hem ex ends h oughou he wen ie h cen u y, and i is
exponen ial, while he second one is om he yea 2000 o he p esen , and i is linea . In he i s
o he pe iods, he adjus men o he end line is op imal, gi ing ise o a eg ession coe icien R
2
g ea e han 0.9. The only da a ha sepa a es om his end line co esponds o he numbe o a icles
published in he yea 1946, which is 429. This da a is abno mally high. In ac , i is no eached and
exceeded comple ely un il he 1980s. The explana ion o his is ound in wo miles ones o g ea
impo ance in he igh agains mala ia ha ook place in ha yea . On he one hand, chlo oquine was
ecognized and es ablished as an e ec i e and sa e an imala ial agen [
37
]. And, on he o he hand,
In . J. En i on. Res. Public Heal h 2018,15, 2703 5 o 14
he CDC (Communicable Disease Cen e ) was c ea ed om he O ice o MCMA (Mala ia Con ol in
Wa A eas), whose main objec i e was o igh agains diseases such as mala ia in he Sou h o he
Uni ed S a es du ing he Second Wo ld Wa . Cu en ly, he CDC is he main No h Ame ican public
heal h agency and i s mission is “collabo a e o c ea e he expe ise, in o ma ion, and ools ha people,
and communi ies need o p o ec hei heal h— h ough heal h p omo ion, p e en ion o disease, inju y,
and disabili y—and p epa edness o new heal h h ea s.” Al hough he ini ial objec i e o he CDC
was he con ol and elimina ion o mala ia, i s cu en ole is aimed a p e en ion and su eillance,
because i is conside ed e adica ed in he USA since 1951.
In . J. En i on. Res. Public Heal h 2018, 15, x 5 o 14
Sou h o he Uni ed S a es du ing he Second Wo ld Wa . Cu en ly, he CDC is he main No h
Ame ican public heal h agency and i s mission is “collabo a e o c ea e he expe ise, in o ma ion,
and ools ha people, and communi ies need o p o ec hei heal h— h ough heal h p omo ion,
p e en ion o disease, inju y, and disabili y—and p epa edness o new heal h h ea s.” Al hough
he ini ial objec i e o he CDC was he con ol and elimina ion o mala ia, i s cu en ole is aimed
a p e en ion and su eillance, because i is conside ed e adica ed in he USA since 1951.
Figu e 2. Publica ions ends on Mala ia om 1900–2017.
The second pe iod ha can be obse ed in Figu e 2 is adjus ed o a linea end line. I s slope is
m = 159. Tha is, since 2000, each yea , he a e age numbe o a icles ha ha e been published g ows
by mo e han 150 uni s. This highligh s he eno mous in e es ha esea ch a ound mala ia has, a
p esen .
3.2. Au ho s and Coun ies in Mala ia Resea ch
In he 85,370 published a icles on mala ia in he pe iod s udied, 148,876 au ho s and a o al o
2,211,628 collabo a ions appea among hem. In Table 1, he 20 mos impo an au ho s can be
obse ed. To es ablish his anking, he eigen ec o cen ali y o eigencen ali y has been aken in o
accoun . In g aph heo y his is used o highligh he in luence o a node in a ne wo k. O he alues
ha could be used o measu e he impo ance o an au ho a e he H-index [38], he numbe o
published a icles, o he numbe o ci a ions ecei ed by hese a icles. Bu he possibili y ha an
au ho has wo ked in di e en a eas o hemes could mask he esul . Howe e , a high sco e o he
eigen ec o is di ec ly ela ed o he alue ha an au ho has wi hin a ne wo k in which each au ho
is iden i ied wi h a node, and in which he connec ions o each node a e p e e ably sco ed wi h o he
nodes o a high sco e. Figu e 3-A shows he 455 au ho s ep esen ed by nodes wi h an eigencen ali y
alue g ea e han 0.2, and hei connec ions wi h he es o he nodes (au ho s). Figu e 3-B shows
he 158 au ho s ep esen ed by nodes wi h an eigencen ali y alue g ea e han 0.4, and Figu e 3-C
shows he 31 au ho s ep esen ed by nodes wi h an eigencen ali y alue g ea e han 0.6. The e y
high densi y o ela ions ha exis be ween au ho s, i is possible o emphasize abo e all wi h an
eigen ec o >0.2. The size o each node is p opo ional o he alue o i s eigencen ali y, and he colo
is ep esen a i e o he coun y om which he au ho ´s ins i u ional a ilia ion.
Figu e 2. Publica ions ends on Mala ia om 1900–2017.
The second pe iod ha can be obse ed in Figu e 2is adjus ed o a linea end line. I s slope
is m= 159. Tha is, since 2000, each yea , he a e age numbe o a icles ha ha e been published
g ows by mo e han 150 uni s. This highligh s he eno mous in e es ha esea ch a ound mala ia has,
a p esen .
3.2. Au ho s and Coun ies in Mala ia Resea ch
In he 85,370 published a icles on mala ia in he pe iod s udied, 148,876 au ho s and a o al
o 2,211,628 collabo a ions appea among hem. In Table 1, he 20 mos impo an au ho s can be
obse ed. To es ablish his anking, he eigen ec o cen ali y o eigencen ali y has been aken in o
accoun . In g aph heo y his is used o highligh he in luence o a node in a ne wo k. O he alues
ha could be used o measu e he impo ance o an au ho a e he H-index [
38
], he numbe o
published a icles, o he numbe o ci a ions ecei ed by hese a icles. Bu he possibili y ha an
au ho has wo ked in di e en a eas o hemes could mask he esul . Howe e , a high sco e o he
eigen ec o is di ec ly ela ed o he alue ha an au ho has wi hin a ne wo k in which each au ho is
iden i ied wi h a node, and in which he connec ions o each node a e p e e ably sco ed wi h o he
nodes o a high sco e. Figu e 3A shows he 455 au ho s ep esen ed by nodes wi h an eigencen ali y
alue g ea e han 0.2, and hei connec ions wi h he es o he nodes (au ho s). Figu e 3B shows
he 158 au ho s ep esen ed by nodes wi h an eigencen ali y alue g ea e han 0.4, and Figu e 3C
shows he 31 au ho s ep esen ed by nodes wi h an eigencen ali y alue g ea e han 0.6. The e y
high densi y o ela ions ha exis be ween au ho s, i is possible o emphasize abo e all wi h an
eigen ec o >0.2. The size o each node is p opo ional o he alue o i s eigencen ali y, and he colo
is ep esen a i e o he coun y om which he au ho ’s ins i u ional a ilia ion.
In . J. En i on. Res. Public Heal h 2018,15, 2703 6 o 14
Table 1. Lis o au ho s mos equen in mala ia esea ch a icles.
Au ho Eigencen ali y NmN H-Index Coau ho Ci es Coun y
Ma sh K. 1.000000 392 468 84 1748 26032 Kenya
Djimde A. 0.995692 120 123 33 1052 4656 Mali
D akeley C. 0.965505 284 294 58 1781 11934 Uni ed Kingdom
Doumbo O. 0.957462 389 424 56 1921 13477 Mali
Nos en F. 0.829049 512 568 78 2160 23142 Thailand
Ouéd aogo J. 0.816295 119 147 29 962 3137 Bu kina Faso
Bo mann S. 0.816208 87 87 31 676 3818 Kenya
Muelle I. 0.808423 276 289 40 1224 5830 Aus alia
P ice R. 0.786288 227 241 54 1150 9966 Uni ed Kingdom
Hien T. 0.786204 246 271 70 1763 19209 Vie Nam
Plowe C. 0.749014 179 187 55 1216 10896 Uni ed S a es
D’Alessand o U.
0.746263 298 315 43 1483 7497 Uni ed Kingdom
Whi e N. 0.726106 897 1146 114 3134 52466 Thailand
Mayxay M. 0.703699 113 117 32 866 3941 Laos
Bousema T. 0.702141 136 165 34 827 4205 Uni ed Kingdom
Kwia kowski D. 0.690173 270 335 63 2069 17684 Uni ed Kingdom
Dondo p A. 0.685832 285 312 52 1367 10554 Ne he lands
Ogu u B. 0.681686 130 139 27 1017 3031 Kenya
Fanello C. 0.680121 42 43 21 508 2648 Thailand
G eenwood B. 0.676612 458 893 77 1848 23579 Uni ed Kingdom
Nm, numbe o a icles published on mala ia; N , numbe o o al a icles published, including hose whose main
opic is no mala ia; Coau ho , numbe o co-au ho s ha appea in a icles published on mala ia; Ci es, numbe o
ci a ions ha ha e ecei ed a icles published on mala ia.
In . J. En i on. Res. Public Heal h 2018, 15, x 6 o 14
Table 1. Lis o au ho s mos equen in mala ia esea ch a icles.
Au ho
Eigencen ali y Nm N H-Index Coau ho Ci es Coun y
Ma sh K. 1.000000 392 468 84 1748 26032 Kenya
Djimde A. 0.995692 120 123 33 1052 4656 Mali
D akeley C. 0.965505 284 294 58 1781 11934 Uni ed Kingdom
Doumbo O. 0.957462 389 424 56 1921 13477 Mali
Nos en F. 0.829049 512 568 78 2160 23142 Thailand
Ouéd aogo J. 0.816295 119 147 29 962 3137 Bu kina Faso
Bo mann S. 0.816208 87 87 31 676 3818 Kenya
Muelle I. 0.808423 276 289 40 1224 5830 Aus alia
P ice R. 0.786288 227 241 54 1150 9966 Uni ed Kingdom
Hien T. 0.786204 246 271 70 1763 19209 Vie Nam
Plowe C. 0.749014 179 187 55 1216 10896 Uni ed S a es
D’Alessand o U. 0.746263 298 315 43 1483 7497 Uni ed Kingdom
Whi e N. 0.726106 897 1146 114 3134 52466 Thailand
Mayxay M. 0.703699 113 117 32 866 3941 Laos
Bousema T. 0.702141 136 165 34 827 4205 Uni ed Kingdom
Kwia kowski D. 0.690173 270 335 63 2069 17684 Uni ed Kingdom
Dondo p A. 0.685832 285 312 52 1367 10554 Ne he lands
Ogu u B. 0.681686 130 139 27 1017 3031 Kenya
Fanello C. 0.680121 42 43 21 508 2648 Thailand
G eenwood B. 0.676612 458 893 77 1848 23579 Uni ed Kingdom
Nm, numbe o a icles published on mala ia; N , numbe o o al a icles published, including hose
whose main opic is no mala ia; Coau ho , numbe o co-au ho s ha appea in a icles published on
mala ia; Ci es, numbe o ci a ions ha ha e ecei ed a icles published on mala ia.
Figu e 3 a emp s o ep esen he ela ionship be ween au ho s om di e en coun ies, as well
as hei ele ance. The e o e, a isualiza ion (by colo ) o he au ho s om he di e en coun ies is
sough , ob aining a gene al idea o which coun ies p e ail o e o he s, as well as he ele ance o
he main au ho s om one coun y e sus au ho s om o he coun ies. Due o he la ge numbe o
nodes (au ho s) i is no possible o indica e hei names.
Figu e 3. Con .
In . J. En i on. Res. Public Heal h 2018,15, 2703 7 o 14
In . J. En i on. Res. Public Heal h 2018, 15, x 7 o 14
Figu e 3. G aph ep esen ing by nodes he na ionali y o he au ho s wi h an eigencen ali y alue
and hei connec ions wi h he es o he nodes (au ho s). (A) G ea e han 0.2; (B) G ea e han 0.4;
(C) G ea e han 0.6.
As can be obse ed in Table 1, he i s 20 au ho s in mala ia esea ch belong o en di e en
coun ies. These can be conside ed in wo g oups. On he one hand, he A ican (Kenya, Mali and
Bu kina Faso) and Asians (Thailand, Vie Nam and Laos) coun ies, o g ea impo ance o he
numbe o es ima ed cases and dea hs p oduced by mala ia; and, on he o he hand, he Eu opean
(Uni ed Kingdom, and Ne he lands), Ame ican (USA) and Aus alian (Aus alia) coun ies, o g ea
impo ance o he numbe o a icles published. Figu e 4 shows he coun ies wi h he highes
numbe o cases es ima ed by he Wo ld Heal h O ganiza ion in he pe iod 2010–2016 (Figu e 4A),
which ha e p esen ed a g ea e numbe o dea hs es ima ed in ha same pe iod (Figu e 4B), and
hose ha ha e published he mos a icles in 1900–2017 (Figu e 4C). Bu kina Faso and Mali a e
among he i e coun ies wi h he highes numbe o dea hs, while he Uni ed S a es and he Uni ed
Kingdom a e he wo coun ies whose ins i u ions publish he mos a icles on mala ia. Fo his
eason, i is no su p ising ha he main esea che s wo king in hese coun ies a e hose wi h he
highes eigencen ali y.
Figu e 3.
G aph ep esen ing by nodes he na ionali y o he au ho s wi h an eigencen ali y alue
and hei connec ions wi h he es o he nodes (au ho s). (
A
) G ea e han 0.2; (
B
) G ea e han 0.4;
(C) G ea e han 0.6.
Figu e 3a emp s o ep esen he ela ionship be ween au ho s om di e en coun ies, as well
as hei ele ance. The e o e, a isualiza ion (by colo ) o he au ho s om he di e en coun ies is
sough , ob aining a gene al idea o which coun ies p e ail o e o he s, as well as he ele ance o he
main au ho s om one coun y e sus au ho s om o he coun ies. Due o he la ge numbe o nodes
(au ho s) i is no possible o indica e hei names.
As can be obse ed in Table 1, he i s 20 au ho s in mala ia esea ch belong o en di e en
coun ies. These can be conside ed in wo g oups. On he one hand, he A ican (Kenya, Mali and
Bu kina Faso) and Asians (Thailand, Vie Nam and Laos) coun ies, o g ea impo ance o he
numbe o es ima ed cases and dea hs p oduced by mala ia; and, on he o he hand, he Eu opean
(Uni ed Kingdom, and Ne he lands), Ame ican (USA) and Aus alian (Aus alia) coun ies, o g ea
impo ance o he numbe o a icles published. Figu e 4shows he coun ies wi h he highes numbe
o cases es ima ed by he Wo ld Heal h O ganiza ion in he pe iod 2010–2016 (Figu e 4A), which
ha e p esen ed a g ea e numbe o dea hs es ima ed in ha same pe iod (Figu e 4B), and hose
ha ha e published he mos a icles in 1900–2017 (Figu e 4C). Bu kina Faso and Mali a e among
he i e coun ies wi h he highes numbe o dea hs, while he Uni ed S a es and he Uni ed
Kingdom a e he wo coun ies whose ins i u ions publish he mos a icles on mala ia. Fo his
eason, i is no su p ising ha he main esea che s wo king in hese coun ies a e hose wi h he
highes eigencen ali y.
In . J. En i on. Res. Public Heal h 2018,15, 2703 8 o 14
In . J. En i on. Res. Public Heal h 2018, 15, x 8 o 14
Figu e 4. Wo ld map on mala ia: (A) Cases es ima ed by he Wo ld Heal h O ganiza ion in he pe iod
2010–2016; (B) Numbe o dea hs es ima ed by he Wo ld Heal h O ganiza ion in he pe iod 2010–
2016; (C) Numbe o publica ions on mala ia in he pe iod 1900–2017.
3.3. Communi ies De ec ion
F om 85,370 published a icles, 714,979 ci a ions we e coun ed— he ci a ions o nodes o opics
o he han mala ia we e no included. On he o he hand, 149,143 keywo ds de ined by he au ho s
appea in hese a icles. Bo h da a allow us, using gene ic algo i hms, o es ablish a se ies o hema ic
SC, o which, he mos equen a e ep esen ed in Table 2. In he able only appea SC composed o
a leas 1% o he o al o 85,370 a icles published. To supplemen Table 2, Figu e 5 has been ca ied
ou . The in o ma ion ha codi ies Figu e 5 has o do wi h he ela i e size o one communi y in on
o he o he as well as he p oximi y o ce ain communi ies o each o he , depending on how close
he nodes in he g aph a e.
Figu e 4.
Wo ld map on mala ia: (
A
) Cases es ima ed by he Wo ld Heal h O ganiza ion in he pe iod
2010–2016; (
B
) Numbe o dea hs es ima ed by he Wo ld Heal h O ganiza ion in he pe iod 2010–2016;
(C) Numbe o publica ions on mala ia in he pe iod 1900–2017.
3.3. Communi ies De ec ion
F om 85,370 published a icles, 714,979 ci a ions we e coun ed— he ci a ions o nodes o opics
o he han mala ia we e no included. On he o he hand, 149,143 keywo ds de ined by he au ho s
appea in hese a icles. Bo h da a allow us, using gene ic algo i hms, o es ablish a se ies o hema ic
SC, o which, he mos equen a e ep esen ed in Table 2. In he able only appea SC composed o a
leas 1% o he o al o 85,370 a icles published. To supplemen Table 2, Figu e 5has been ca ied ou .
The in o ma ion ha codi ies Figu e 5has o do wi h he ela i e size o one communi y in on o he
o he as well as he p oximi y o ce ain communi ies o each o he , depending on how close he nodes
in he g aph a e.
In . J. En i on. Res. Public Heal h 2018,15, 2703 9 o 14
Table 2. Main scien i ic communi ies in mala ia esea ch.
Comm. % Communi y Topic Keywo d 1 Keywo d 2 Keywo d 3 Keywo d 4 Keywo d 5
#1 5.64 Mosqui oes and insec icides An. gambiae Anopheles P. alcipa um Mala ia ec o Vec o con ol
#2 5.40 D ug esis ance P. alcipa um A emisinin Chlo oquine D ug esis ance An imala ial
#3 3.28 Apicomplexa P. alcipa um Plasmodium P. be ghei Apicoplas E y h ocy e
#4 3.16 Se e e mala ia P. alcipa um Ce eb al mala ia Cy okines Se e e mala ia Child en
#5 3.13 Mala ia diagnosis P. alcipa um Diagnosis Mic oscopy Plasmodium P. i ax
#6 3.05 Vaccines P. alcipa um Vaccine Plasmodium P. i ax Mala ia accine
#7 1.77 P egnancy and VIH P egnancy P. alcipa um HIV Placen a Anemia
#8 1.44 Plasmodium i ax P. i ax P. alcipa um P imaquine Chlo oquine Th ombocy openia
#9 1.35 Mosqui oes and immuni y Mosqui o P. alcipa um Plasmodium An. gambiae Anopheles
#10 1.31 T a el and d ugs P. alcipa um Me loquine Chemop ophylaxis T a el P ophylaxis
#11 1.03
Glucose-6-phospha e dehyd ogenase
P. alcipa um G6PD de iciency Oxida i e s ess Thalassemia Sickle cell disease
Comm., communi y; An. Anopheles;P. Plasmodium. %, pe cen age o a icles belonging o a communi y wi h espec o he o al numbe o published a icles in mala ia.
