Association of zoonotic Ljungan virus with intrauterine fetal deaths.
BACKGROUND
It has recently been shown that Ljungan virus (LV) is associated with disease in its wild rodent reservoir. In addition, it has been demonstrated that LV causes malformations and perinatal death in a mouse model. The question was therefore raised whether LV is a zoonotic agent in humans.


METHODS
Population fluctuations of native rodents in Sweden were compared to the incidence of intrauterine fetal deaths (IUFDs) using the Swedish national hospitalization database. Formalin-fixed tissues from cases of IUFD were investigated using LV-specific immunohistochemistry.


RESULTS
Variation in the incidence of IUFDs closely tracked the fluctuations in native rodent populations. LV was detected in the brain tissue in 4 of 10 cases of IUFDs investigated by immunochemistry. LV was also detected in the placenta in 5 of the 10 IUFD cases, but in none of 20 placentas from normal pregnancies.


CONCLUSIONS
LV may play an important role in IUFDs.
Niklasson
Bo
B
Apodemus AB, Grevgatan 38, Stockholm, Sweden. Bo.Niklasson@Apodemus.se
Samsioe
Annika
A
Papadogiannakis
Nikos
N
Kawecki
Anne
A
Hörnfeldt
Birger
B
Saade
George R
GR
Klitz
William
W
D000818:Animals; D003411:Arvicolinae / Q000821:virology; D001921:Brain / Q000821:virology; D016022:Case-Control Studies; D004195:Disease Models, Animal; D005260:Female; D005313:Fetal Death / Q000209:etiology*; D006801:Humans; D007124:Immunoenzyme Techniques; D007231:Infant, Newborn; D008297:Male; D030061:Parechovirus / Q000472:pathogenicity*; D010850:Picornaviridae Infections / Q000150:complications*; D010920:Placenta / Q000821:virology; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology / Q000209:etiology*; D011256:Pregnancy Outcome; D012376:Rodent Diseases / Q000453:epidemiology / Q000209:etiology; D013548:Sweden / Q000453:epidemiology