Analysis of two imported cases of yellow fever infection from Ivory Coast and The Gambia to Germany and Belgium.
BACKGROUND
Yellow fever remains one of the great burdens for public health in the endemic regions in Africa and South America. The under reporting of yellow fever cases in the respective regions and lack of international interest leads to an underestimation of the constant danger in these areas. Non-vaccinated travelers take a high risk without the effective protection of YFV 17D vaccination.


OBJECTIVE
Two YF cases were imported to Europe in the last 4 years. We characterized two yellow fever virus (YFV) isolates from severely infected patients coming back from Africa, Ivory Coast and The Gambia, by genome sequencing and phylogenetic analysis.


METHODS
The virus infections in different organs were analyzed with pathological, immunohistological, electronmicroscopical and quantitative real-time PCR methods.


CONCLUSIONS
High virus loads in spleen and liver (2.4 x 10 (6) to 3 x 10 (7)GE/mL) demonstrated by real time PCR show massive virus replication leading to extraordinary progression of the disease in these patients. Immunohistological and electronmicroscopical analysis confirms virus particles in liver tissue. In all other organs no virus could be detected. A fast, specific and sensitive virus PCR detection is recommended for diagnostic of acute infections. The further sequence alignments show that the new isolates belong to the type II West African strain with great homology to over 40-year old YF isolates from Senegal and Ghana. The divergence observed was on average 3.3%, ranging from 0.0% to 5.0% in the coding region of Gambia 2001 strain and 2.9 %, ranging from 0.0% to 4.3% in the coding region of the Ivory C 1999 strain. Most mutations (5.0%/4.3%, respectively) occurred in the envelope protein.
Bae
Hi-Gung
HG
Robert Koch-Institute, Nordufer 20, 13353 Berlin, Germany.
Drosten
Christian
C
Emmerich
Petra
P
Colebunders
Robert
R
Hantson
Philippe
P
Pest
Stefan
S
Parent
Muriel
M
Schmitz
Herbert
H
Warnat
Marc-Aurel
MA
Niedrig
Matthias
M
D001483:Base Sequence; D001530:Belgium; D007560:Cote d'Ivoire; D017809:Fatal Outcome; D005260:Female; D005714:Gambia; D005858:Germany; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D014195:Travel; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics; D015004:Yellow Fever / Q000175:diagnosis* / Q000821:virology; D015005:Yellow fever virus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
D014759:Viral Envelope Proteins; C074932:prM protein, Flavivirus