Sweedish Study says SIDS due to Rodent Infestation?

LJUNGAN VIRUS, SUDDEN INFANT DEATH SYNDROME - SWEDEN
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A ProMED-mail post

ProMED-mail is a program of the
International Society for Infectious Diseases


Date: Wed 13 May 2009
Source: Ljugan virus Newsletter [edited]



Ljungan virus might be a major etiological agent in sudden infant death
syndrome [SIDS]. This hypothesis is reported in the scientific journal
Forensic Science, Medicine and Pathology [Forensic Sci Med Pathol. 2009 May
1 (Epub ahead of print) -- see abstract below].

The proposal rests on 3 distinct lines of evidence: the new finding of
Ljungan virus (LV) in brain, heart, and lung tissue in cases of sudden
infant death syndrome (SIDS), the observation that LV causes a related
disease in various species of animals, and the association between the
incidence of SIDS and the abundance of an animal reservoir of LV. In
addition, recently, the scientific journal Birth Defects Research reported
that LV is also associated with intrauterine fetal death and malformations
(hydrocephaly and anencephaly).

--
communicated by:
ProMED-mail

[Ljungan virus is a parechovirus. The genus _Parechovirus_ is one of the 9
genera comprising the family _Picornaviridae_ and includes 2 species,
_Human parechovirus_ and _Ljungan virus_. According to Virus Taxonomy (The
Eighth Report of the International Committee on Taxonomy of Viruses), the
human parechoviruses replicate in the respiratory and gastrointestinal
tracts. Infection is particularly prevalent in young children but is
probably mostly asymptomatic. In addition to respiratory infections and
diarrhea, infections of the central nervous system have been reported
occasionally. Isolates of Ljungan virus appear to infect predominantly
rodents. The predicted protein sequences of parechoviruses are highly
divergent, with no protein having a greater than 30 per cent level of
identity compared with corresponding proteins of any other member of the
family _Picornaviridae_. The American and Swedish isolates of Ljungan virus
show considerable divergence.

The following is the abstract of the paper which is the subject of the
preceding announcement:

Niklasson B, Almqvist PR, Hornfeldt B, Klitz W. Sudden infant death
syndrome and Ljungan virus. Forensic Sci Med Pathol 2009 May 1 (Epub ahead
of print)

"Ljungan virus (LV) has recently been associated with perinatal death in
its natural rodent reservoir and also with developmental disorders of
reproduction in laboratory mice. A strong epidemiological association has
been found between small rodent abundance in Sweden and the incidence of
intrauterine fetal death (IUFD) in humans. LV antigen has been detected in
half of the IUFD cases tested [see ProMED-mail archived reports below].

"The question was therefore raised whether sudden infant death syndrome
(SIDS) might be associated with rodent abundance, and whether the virus is
present in cases of SIDS. Variation in the incidence of SIDS using the
Swedish cause-of-death database tracked the changes in the population
fluctuations of native rodents. Formalin-fixed tissues from the brain,
heart, and lung were investigated from cases of SIDS, SIDS with lymphocytic
infiltration of the myocardium (myocarditis) and myocarditis cases using LV
specific immunohistochemistry (IHC). Ljungan virus was detected in the
brain, heart, and lung tissue from all 3 of the patient categories
investigated using IHC. These studies suggest that LV may play a prominent
role in infant death and that IUFD and SIDS may have common etiological
underpinnings."

This research further implicates Ljungan virus as a potential etiologic
agent in human disease. However, the possibility cannot yet be excluded
that it is no more than an innocuous passenger in view of the diversity of
the conditions associated with Ljungan virus. - Mod.CP]

[see also;
Ljungan virus, intrauterine fetal death - Sweden (02) 20090202.0459
Ljungan virus, intrauterine fetal death - Sweden 20090129.0400]

.....................cp/msp/sh