LCMV Lymphocytic choriomeningitis virus is a rodent-borne pathogen belongs to Arenaviridae family. Most of the studies have referred Mus musculus as the main reservoir of the LCMV. It has been detected in pet rodents, laboratory rodents, and wild mice. Humans be infected with LCMV through the ingestion or inhalation of sources contaminated with rodent feces, urine, or both. LCMV infection can be asymptomatic, present with mild symptoms, or it can cause aseptic meningoencephalitis (AME) and teratogenic effects in infants. However, clinical cases of LCMV infection have been rarely reported, and there is only fragmental knowledge on the presence and prevalence of LCMV infections around the world. Likewise, the genetic characteristics of the circulating LCMV strains and impact of LCMV on public health have remained poorly characterized. This study was performed in the Southern Iraq, due to the lack of comprehensive information about LCMV in this area.
There were three main aims in this thesis. First, to assess the prevalence of LCMV among the healthy human population in the Nasiriyah region, southern Iraq. Second, to assess whether LCMV infections can be associated with neurological manifestations. Third, to characterize the genetic variation and evolutionary history of LCMV strains circulating in southern Iraq.
Serum and CSF samples were collected from patients and healthy people in Nasiriyah governorate in the Southern Iraq. Serum samples were screened for LCMV using Immunofluorescence assay (IFA) to detect IgG and IgM antibodies. Real-time PCR was used to detect LCMV genome. In order to confirm the PCR positive samples, we sequenced these samples by Next-generation sequencing.
The serological assay results showed 12.22% IgG prevalence of LCMV among healthy people and 7.36% IgG prevalence among patients with neurological symptoms. The IgM prevalence was 1.25% among the patients with acute infections. From symptomatic patients, we sequenced partial L-segments of two new LCMV strains. The phylogenetic tree constructed on the basis of all known LCMV strains suggested that these new LCMV strains from Iraq are genetically distant from the previously known LCMV strains and form a novel sub-cluster within LCMV species.
This study is the first survey of LCMV in the Southern Iraq. LCMV appears to be a rather common infection in Iraq. I reported new strains of LCMV that are circulating in the study site and most likely is the causative agent of the central nervous system-associated clinical manifestations in these patients. For future work, I’m aiming the detection of other Arenaviruses spreading in the Southern Iraq.
