tetano
Editor, Senior Moderator
IQUITOS VIRUS - PERU: (IQUITOS), NOVEL HUMAN PATHOGEN
*****************************************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>
Date: Tue 20 Sep 2011
Source: PLoS Negl. Trop. Dis. 5(9): e1315 [modified, edited]
<http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001315>
Iquitos Virus: A Novel Reassortant Orthobunyavirus associated with
human illness in Peru
----------------------------------------------------------------------------------------
Oropouche (ORO) virus is one of the few human pathogens in the genus
_Orthobunyavirus_ in the family _Bunyaviridae_. Phylogenetic analyses
of ORO-like strains isolated from febrile patients in Iquitos, Peru,
identified a novel ORO reassortant virus, which the authors have named
Iquitos (IQT) virus based on the location of the isolation of the
virus. This novel pathogen was 1st isolated during 1999 from a
13-year-old boy who had an illness that included symptoms of fever,
headache, eye pain, body pain, arthralgias, diarrhea, and chills.
Subsequently, the virus was identified as the cause of outbreaks of
"Oropouche fever" during 2005 and 2006 in Iquitos. Limited serological
studies indicate that prior infection with ORO virus did not seem to
protect against disease caused by IQT virus infection. In summary, the
authors have identified a new Orthobunyavirus human pathogen in the
Amazon region of Peru, which genetically is a reassortant virus
These findings are described in the 20 Sep 2011 edition of PLoS
Neglected Tropical Diseases: Aguilar PV, Barrett AD, Saeed MF, Watts
DM, Russell K, et al. (2011) Iquitos Virus: A Novel Reassortant
Orthobunyavirus Associated with Human Illness in Peru. PLoS Negl Trop
Dis 5(9): e1315. doi:10.1371/journal.pntd.0001315
The Abstract of this paper reads: "Oropouche (ORO) virus, a member of
the Simbu serogroup, is one of the few human pathogens in the
_Orthobunyavirus_ genus of the family _Bunyaviridae_. Genetic analyses
of ORO-like strains from Iquitos, Peru, identified a novel reassortant
containing the S and L genome segments of ORO virus and the M segment
of a novel Simbu serogroup virus. This new pathogen, which is named
Iquitos (IQT) virus, was 1st isolated during 1999 from a febrile
patient in Iquitos, an Amazonian city in Peru. Subsequently, the virus
was identified as the cause of outbreaks of "Oropouche fever" during
2005 and 2006 in Iquitos. In addition to the identification of 17
isolates of IQT virus between 1999 and 2006, surveys for neutralizing
antibody among Iquitos residents revealed prevalence rates of 14.9
percent for ORO virus and 15.4 percent for IQT virus. Limited studies
indicate that prior infection with ORO virus does not seem to protect
against disease caused with the IQT virus infection.
ORO virus has been isolated from mosquitoes (_Coquillettidia
venezuelensis_, _Ochlerotatus serratus_ and _Culex quinquefasciatus_
in Brazil) and frequently from the midge _Culicoides paraensis_. High
population densities of this midge have been found during epidemics of
ORO virus, and it is likely that IQT virus is transmitted by the same
vectors.
Interested readers should access the full text to appreciate the
extent of this investigation. The following passages from from the
text of the paper have been selected to set these findings in
context.
"Viruses in the family _Bunyaviridae_ are classified into 5 genera:
_Orthobunyavirus_, _Hantavirus_, _Nairovirus_, _Phlebovirus_ and
_Tospoviruses_. The orthobunyaviruses are enveloped, negative sense
RNA viruses whose genome comprises 3 segments: small (S), medium (M)
and large (L). The S segment encodes for the nucleocapsid and a
nonstructural protein, NS. The M segment encodes for the glycoproteins
Gn and Gc, whereas the L segment encodes the viral polymerase."
"Some members of the _Orthobunyavirus_ genus are known to cause
clinical disease in humans, including Oropouche (ORO) virus, a member
of the Simbu serogroup, which causes a febrile disease often
associated with headache, dizziness, weakness, myalgias and
arthralgias. Bunyamwera virus, which is considered the prototype
member of the family, causes a febrile illness with headache,
arthralgias, rash and infrequent central nervous system involvement.
Hemorrhagic manifestations associated with some orthobunyavirus
infections have also been reported recently."
"Genetic reassortment among members of the same serogroup within the
_Orthobunyavirus_ genus occurs in nature and has led to the emergence
of new viruses, only occasionally with increased pathogenicity. This
appears to be the case with Ngari virus, which has been associated
with hemorrhagic fever in Kenya and Somalia. This virus is comprised
of the S and L segments of Bunyamwera virus and the M segment of Batai
virus. On the basis of genetic and antigenic analyses, the authors
previously reported that Jatobal virus (JAT), a member of the Simbu
serogroup, is a reassortant virus that contains the S segment of ORO
virus and the M and L segments of a still unrecognized Simbu serogroup
virus."
"In 1995, the U.S. Naval Medical Research Unit Six (NAMRU-6) in Lima,
in collaboration with the Ministry of Health of Peru, initiated a
passive surveillance study to investigate etiology of febrile
illnesses. As part of these surveillance activities, several ORO-like
strains were obtained from febrile patients in Iquitos, Peru. In this
study, a novel reassortant virus which was named Iquitos (IQT) based
on the location of the isolation of the virus. Specifically, it was
demonstrated that: 1) IQT virus causes clinical disease in humans
similar to ORO fever, 2) the genetic relationship of IQT virus to
other members of the Simbu serogroup, 3) risk factors associated with
human infection by IQT virus in an urban setting of the Amazon region
of Peru were identified, and 4) clinical manifestations were
associated with infection. Significantly, immunity to ORO virus does
not appear to protect against infection by IQT virus, and both ORO and
IQT viruses appear to have similar antibody prevalence in Iquitos over
the past 10 years."
--
Communicated by:
ProMED-mail
<promed@promedmail.org>
[It is evident that a new human pathogen, IQT virus, has been
identified that is a reassortant of ORO virus, a virus that was
associated previously with febrile illness in the Amazon region of
Peru. The name Iquitos virus is proposed for this newly identified
Orthobunyavirus member of the Simbu-serogroup because there have been
cases of disease caused by this virus in the Iquitos area over several
years.
Although reassortment among members of the same serogroup of the
family _Bunyaviridae_is a well-established phenomenon, few
reassortants have been associated with human disease. It will be
important in future work to determine the geographic distribution of
Iquitos virus and to evaluate its potential as a major public health
problem as has been confirmed for ORO virus in Brazil. These results
highlight the need for strengthening surveillance activities and
investigating the emergence of new pathogens in tropical regions of
South America.
Iquitos is a city of about 380 000 inhabitants located 120 meters (394
feet) above sea level in the Amazon Basin in northeastern Peru. A map
showing the location of Iquitos can be accessed at:
<http://www.inkanatura.com/map_iquitos.asp>. - Mod.CP]
http://www.promedmail.org/pls/otn/f..._BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1000,90383
*****************************************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>
Date: Tue 20 Sep 2011
Source: PLoS Negl. Trop. Dis. 5(9): e1315 [modified, edited]
<http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001315>
Iquitos Virus: A Novel Reassortant Orthobunyavirus associated with
human illness in Peru
----------------------------------------------------------------------------------------
Oropouche (ORO) virus is one of the few human pathogens in the genus
_Orthobunyavirus_ in the family _Bunyaviridae_. Phylogenetic analyses
of ORO-like strains isolated from febrile patients in Iquitos, Peru,
identified a novel ORO reassortant virus, which the authors have named
Iquitos (IQT) virus based on the location of the isolation of the
virus. This novel pathogen was 1st isolated during 1999 from a
13-year-old boy who had an illness that included symptoms of fever,
headache, eye pain, body pain, arthralgias, diarrhea, and chills.
Subsequently, the virus was identified as the cause of outbreaks of
"Oropouche fever" during 2005 and 2006 in Iquitos. Limited serological
studies indicate that prior infection with ORO virus did not seem to
protect against disease caused by IQT virus infection. In summary, the
authors have identified a new Orthobunyavirus human pathogen in the
Amazon region of Peru, which genetically is a reassortant virus
These findings are described in the 20 Sep 2011 edition of PLoS
Neglected Tropical Diseases: Aguilar PV, Barrett AD, Saeed MF, Watts
DM, Russell K, et al. (2011) Iquitos Virus: A Novel Reassortant
Orthobunyavirus Associated with Human Illness in Peru. PLoS Negl Trop
Dis 5(9): e1315. doi:10.1371/journal.pntd.0001315
The Abstract of this paper reads: "Oropouche (ORO) virus, a member of
the Simbu serogroup, is one of the few human pathogens in the
_Orthobunyavirus_ genus of the family _Bunyaviridae_. Genetic analyses
of ORO-like strains from Iquitos, Peru, identified a novel reassortant
containing the S and L genome segments of ORO virus and the M segment
of a novel Simbu serogroup virus. This new pathogen, which is named
Iquitos (IQT) virus, was 1st isolated during 1999 from a febrile
patient in Iquitos, an Amazonian city in Peru. Subsequently, the virus
was identified as the cause of outbreaks of "Oropouche fever" during
2005 and 2006 in Iquitos. In addition to the identification of 17
isolates of IQT virus between 1999 and 2006, surveys for neutralizing
antibody among Iquitos residents revealed prevalence rates of 14.9
percent for ORO virus and 15.4 percent for IQT virus. Limited studies
indicate that prior infection with ORO virus does not seem to protect
against disease caused with the IQT virus infection.
ORO virus has been isolated from mosquitoes (_Coquillettidia
venezuelensis_, _Ochlerotatus serratus_ and _Culex quinquefasciatus_
in Brazil) and frequently from the midge _Culicoides paraensis_. High
population densities of this midge have been found during epidemics of
ORO virus, and it is likely that IQT virus is transmitted by the same
vectors.
Interested readers should access the full text to appreciate the
extent of this investigation. The following passages from from the
text of the paper have been selected to set these findings in
context.
"Viruses in the family _Bunyaviridae_ are classified into 5 genera:
_Orthobunyavirus_, _Hantavirus_, _Nairovirus_, _Phlebovirus_ and
_Tospoviruses_. The orthobunyaviruses are enveloped, negative sense
RNA viruses whose genome comprises 3 segments: small (S), medium (M)
and large (L). The S segment encodes for the nucleocapsid and a
nonstructural protein, NS. The M segment encodes for the glycoproteins
Gn and Gc, whereas the L segment encodes the viral polymerase."
"Some members of the _Orthobunyavirus_ genus are known to cause
clinical disease in humans, including Oropouche (ORO) virus, a member
of the Simbu serogroup, which causes a febrile disease often
associated with headache, dizziness, weakness, myalgias and
arthralgias. Bunyamwera virus, which is considered the prototype
member of the family, causes a febrile illness with headache,
arthralgias, rash and infrequent central nervous system involvement.
Hemorrhagic manifestations associated with some orthobunyavirus
infections have also been reported recently."
"Genetic reassortment among members of the same serogroup within the
_Orthobunyavirus_ genus occurs in nature and has led to the emergence
of new viruses, only occasionally with increased pathogenicity. This
appears to be the case with Ngari virus, which has been associated
with hemorrhagic fever in Kenya and Somalia. This virus is comprised
of the S and L segments of Bunyamwera virus and the M segment of Batai
virus. On the basis of genetic and antigenic analyses, the authors
previously reported that Jatobal virus (JAT), a member of the Simbu
serogroup, is a reassortant virus that contains the S segment of ORO
virus and the M and L segments of a still unrecognized Simbu serogroup
virus."
"In 1995, the U.S. Naval Medical Research Unit Six (NAMRU-6) in Lima,
in collaboration with the Ministry of Health of Peru, initiated a
passive surveillance study to investigate etiology of febrile
illnesses. As part of these surveillance activities, several ORO-like
strains were obtained from febrile patients in Iquitos, Peru. In this
study, a novel reassortant virus which was named Iquitos (IQT) based
on the location of the isolation of the virus. Specifically, it was
demonstrated that: 1) IQT virus causes clinical disease in humans
similar to ORO fever, 2) the genetic relationship of IQT virus to
other members of the Simbu serogroup, 3) risk factors associated with
human infection by IQT virus in an urban setting of the Amazon region
of Peru were identified, and 4) clinical manifestations were
associated with infection. Significantly, immunity to ORO virus does
not appear to protect against infection by IQT virus, and both ORO and
IQT viruses appear to have similar antibody prevalence in Iquitos over
the past 10 years."
--
Communicated by:
ProMED-mail
<promed@promedmail.org>
[It is evident that a new human pathogen, IQT virus, has been
identified that is a reassortant of ORO virus, a virus that was
associated previously with febrile illness in the Amazon region of
Peru. The name Iquitos virus is proposed for this newly identified
Orthobunyavirus member of the Simbu-serogroup because there have been
cases of disease caused by this virus in the Iquitos area over several
years.
Although reassortment among members of the same serogroup of the
family _Bunyaviridae_is a well-established phenomenon, few
reassortants have been associated with human disease. It will be
important in future work to determine the geographic distribution of
Iquitos virus and to evaluate its potential as a major public health
problem as has been confirmed for ORO virus in Brazil. These results
highlight the need for strengthening surveillance activities and
investigating the emergence of new pathogens in tropical regions of
South America.
Iquitos is a city of about 380 000 inhabitants located 120 meters (394
feet) above sea level in the Amazon Basin in northeastern Peru. A map
showing the location of Iquitos can be accessed at:
<http://www.inkanatura.com/map_iquitos.asp>. - Mod.CP]
http://www.promedmail.org/pls/otn/f..._BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1000,90383