Lymphocytic Choriomeningitis
Disease Details
Family Health Simplified
- Description
- Lymphocytic choriomeningitis is a rodent-borne viral infection that primarily affects the central nervous system, causing meningitis, encephalitis, or meningoencephalitis.
- Type
- Lymphocytic choriomeningitis (LCM) is an infectious disease caused by the lymphocytic choriomeningitis virus (LCMV). The type of genetic transmission for LCMV is not inheritable through human genetics; rather, the virus is typically transmitted through exposure to infected rodent secretions, such as urine, droppings, or saliva, and can be transmitted congenitally from an infected mother to her fetus during pregnancy.
- Signs And Symptoms
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LCMV infection manifests itself in a wide range of clinical symptoms, and may even be asymptomatic for immunocompetent individuals. Onset typically occurs between one or two weeks after exposure to the virus and is followed by a biphasic febrile illness. During the initial or prodromal phase, which may last up to a week, common symptoms include fever, lack of appetite, headache, muscle aches, malaise, nausea, and/or vomiting. Less frequent symptoms include a sore throat and cough, as well as joint, chest, and parotid pain. The onset of the second phase occurs several days after recovery, and consists of symptoms of meningitis or encephalitis. Pathological findings during the first stage consist of leukopenia and thrombocytopenia. During the second phase, typical findings include elevated protein levels, increased leukocyte count, or a decrease in glucose levels of the cerebrospinal fluid).Occasionally, a patient improves for a few days, then relapses with aseptic meningitis, or very rarely, meningoencephalitis.
Patients with meningitis may have a stiff neck, fever, headache, myalgia, nausea and malaise. In some occasions, meningitis occurs without a prodromal syndrome. Meningoencephalitis is characterized by more profound neurological signs such as confusion, drowsiness, sensory abnormalities and motor signs. Under reported complications include myelitis, Guillain–Barré-type syndrome, cranial nerve palsies, transient or permanent hydrocephalus, sensorineural hearing loss, orchitis, arthritis and parotitis. LCMV infections have also been associated with pancreatitis, pneumonitis, myocarditis and pericarditis. The entire illness usually lasts 1 to 3 weeks, nonetheless, temporary or permanent neurological damage is possible in all central nervous system infections, especially in cases of meningoencephalitis. Chronic infections have not been reported in humans and deaths rarely occur. - Prognosis
- Lymphocytic choriomeningitis is not a commonly reported infection in humans, though most infections are mild and are often never diagnosed. Serological surveys suggest that approximately 1–5% of the population in the U.S. and Europe has antibodies to LCMV. The prevalence varies with the living conditions and exposure to mice, and it has been higher in the past due to lower standards of living. The island of Vir in Croatia is one of the biggest described endemic places of origin of LCMV in the world, with IFA testing having found LCMV antibodies in 36% of the population. Individuals with the highest risk of infection are laboratory personnel who handle rodents or infected cells. Temperature and time of year is also a critical factor that contributes to the number of LCMV infections, particularly during fall and winter when mice tend to move indoors. Approximately 10–20% of the cases in immunocompetent individuals are thought to progress to neurological disease, mainly as aseptic meningitis. The overall case fatality rate is less than 1% and people with complications, including meningitis, almost always recover completely. Rare cases of meningoencephalitis have also been reported. More severe disease is likely to occur in people who are immunosuppressed.More than 50 infants with congenital LCMV infection have been reported worldwide. The probability that a woman will become infected after being exposed to rodents, the frequency with which LCMV crosses the placenta, and the likelihood of clinical signs among these infants are still poorly understood. In one study, antibodies to LCMV were detected in 0.8% of normal infants, 2.7% of infants with neurological signs and 30% of infants with hydrocephalus. In Argentina, no congenital LCMV infections were reported among 288 healthy mothers and their infants. However, one study found that two of 95 children in a home for people with severe mental disabilities had been infected with this virus. The prognosis for severely affected infants appears to be poor. In one series, 35% of infants diagnosed with congenital infections had died by the age of 21 months.Transplant-acquired lymphocytic choriomeningitis proves to have a very high morbidity and mortality rate. In the three clusters reported in the U.S. from 2005 to 2010, nine of the ten infected recipients died. One donor had been infected from a recently acquired pet hamster while the sources of the virus in the other cases were unknown.
- Onset
- Lymphocytic choriomeningitis (LCM) has an onset period where initial symptoms typically appear 8-13 days following exposure to the virus. Early symptoms can include fever, malaise, lack of appetite, muscle aches, headache, nausea, and vomiting.
- Prevalence
- The exact prevalence of lymphocytic choriomeningitis (LCM) in the general population is not well-documented. However, it is considered to be a rare disease. Most human cases are thought to result from contact with common house mice (Mus musculus), which carry the LCM virus. Occasional outbreaks can occur, particularly in settings where there are large rodent populations.
- Epidemiology
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LCMV has been isolated from fleas, ticks, cockroaches, Culicoides and Aedes mosquitoes. Ticks, lice and mosquitoes have been shown to transmit this virus mechanically in the laboratory. The presence of LCMV in laboratories may cause serious long-term repercussions to worker safety. In 1989, an outbreak among humans occurred in a US cancer research institute that studied the effects of various therapeutic and diagnostic agents in animal models. Such agents had been developed in the animal care facility, which periodically screened sentinel animals for extraneous infection. Due to an oversight, no sentinel animals were monitored from August 1988 to March 1989. When testing resumed, LCMV antibodies were found in the oldest sentinel hamsters. Several workers reported symptoms consistent with LCMV infection, leading to an investigation. Blood samples were obtained and tested for LCMV antibodies. Of the 82 workers that were tested, seven had definite serologic evidence of past LCMV infection, and two were hospitalized for an acute febrile illness. All seven reported direct contact with the animals at the institute.An additional hazard associated with LCMV in laboratories misleading experimental results. Interference with research may involve:
[Inhibition of] tumor induction due to polyoma virus, and mammary tumor virus in the mouse, and [interference] with transplantable leukaemia in the guinea pig and the mouse. Infection is associated with depression of cellular immunity in the mouse. Rejection of cutaneous grafts or transplantable tumors may be delayed. In addition, infection will increase the sensitivity of the mouse to ectromelia virus and to bacterial endotoxins.Reported outbreaks have decreased, perhaps due to improved biohazard management in laboratories. However, it is possible that sporadic cases have been overlooked because of the wide range of clinical presentations. Clare A. Dykewicz, et al. recommend vigilant screening laboratory animals to be used in research facilities either through serum samples or cell line aliquots, as well as ensuring adequate ventilation in housing areas and use of appropriate sanitation products. Other practices to reduce cross-contamination in rodents include washing hands or changing gloves between animal care activities, thoroughly decontaminating cages before reusing them, and avoiding housing healthy rodents in the vicinity of potentially infected rodents. - Intractability
- Lymphocytic choriomeningitis (LCM) is not typically considered intractable. Most individuals recover fully with supportive care. However, the severity of symptoms can vary, and complications may occur, particularly in immunocompromised individuals or during pregnancy.
- Disease Severity
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Lymphocytic choriomeningitis (LCM) disease severity can vary widely among individuals. In most cases, the disease causes mild to moderate symptoms, including fever, lack of appetite, muscle aches, headache, nausea, and vomiting. However, in more severe cases, it can lead to complications such as meningitis (inflammation of the membranes covering the brain and spinal cord), encephalitis (inflammation of the brain), or meningoencephalitis (inflammation of both the brain and its surrounding membranes).
For pregnant women, infection can be particularly serious and may result in congenital infection and severe birth defects in the fetus. Overall, while many people recover fully with supportive care, severe cases may require hospitalization and advanced medical treatment.
The concept "nan" is not applicable in this context as it generally refers to 'Not a Number' in data analysis or computing, which does not relate to disease severity. - Healthcare Professionals
- Disease Ontology ID - DOID:12155
- Pathophysiology
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Lymphocytic choriomeningitis (LCM) is caused by the lymphocytic choriomeningitis virus (LCMV), an arenavirus. The primary host for LCMV is the common house mouse (Mus musculus), and humans can become infected through exposure to contaminated rodent urine, droppings, or nesting materials.
Pathophysiology:
1. **Entry and Initial Replication**: The virus enters the body typically through inhalation or direct contact with contaminated materials. It initially replicates at the site of entry.
2. **Systemic Spread**: LCMV then spreads through the bloodstream (viremia) to various organs, including the liver, spleen, and brain.
3. **Immune Response**: The host immune response is primarily mediated by T cells. In the central nervous system, the immune response can cause inflammation of the meninges (meningitis) and potentially the brain itself (encephalitis).
4. **Inflammation and Damage**: The immune-mediated attack on infected cells leads to inflammation and damage of the meninges and other affected tissues. This causes the characteristic symptoms of lymphocytic choriomeningitis, such as fever, headache, stiff neck, and neurological symptoms.
The severity of the disease typically depends on the immune status of the host and the strain of LCMV. - Carrier Status
- Carrier status: Rodents, particularly common house mice (Mus musculus), are the primary carriers of lymphocytic choriomeningitis virus (LCMV). They can asymptomatically carry and shed the virus in their saliva, urine, and feces. Pets, particularly hamsters and guinea pigs, can also become infected if exposed to the virus from wild rodents.
- Mechanism
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Lymphocytic choriomeningitis (LCM) is caused by the lymphocytic choriomeningitis virus (LCMV), which is an arenavirus. Here’s an overview of its mechanisms and molecular mechanisms:
### Mechanism
1. **Transmission:**
- LCMV is primarily transmitted to humans through exposure to infected rodent excreta, particularly from the common house mouse, Mus musculus.
- Human infection can occur via inhalation of aerosolized virus, direct contact with broken skin, or mucous membranes, and less commonly through organ transplantation or vertical transmission (mother to fetus).
2. **Infection and Spread:**
- After entering the body, LCMV initially infects dendritic cells and macrophages.
- The virus can disseminate to various organs including the liver, spleen, brain, and meninges, leading to widespread tissue involvement.
3. **Immune Response:**
- The immune system mounts a response involving cytotoxic T cells and production of inflammatory cytokines.
- The infection of the meninges and brain parenchyma can result in lymphocytic infiltration and inflammation, causing the characteristic meningitis or meningoencephalitis.
### Molecular Mechanisms
1. **Viral Entry:**
- LCMV binds to its receptor, alpha-dystroglycan (α-DG), which is a ubiquitous cell surface molecule involved in cell adhesion processes.
- Upon binding, the virus enters the host cell through receptor-mediated endocytosis.
2. **Replication:**
- Once inside the cell, LCMV releases its ribonucleoprotein complex into the cytoplasm.
- The viral RNA-dependent RNA polymerase initiates transcription and replication of the viral RNA genome.
- LCMV has a segmented negative-sense RNA genome, which is replicated and transcribed to produce viral mRNAs and new genomic RNAs.
3. **Assembly and Release:**
- Viral proteins and the newly synthesized RNA genomes assemble in the cytoplasm.
- New virions bud from the host cell membrane, incorporating the viral glycoproteins and are released to infect adjacent cells or spread systemically.
4. **Host Immune Evasion:**
- LCMV can modulate the host immune response by interfering with interferon signaling pathways, aiding in its persistence within the host.
- The virus can also evade the immune system by infecting immunologically privileged sites like the central nervous system.
Understanding these mechanisms is critical for developing therapeutic strategies and preventive measures against LCMV infection. - Treatment
- Immunosuppressive therapy has been effective in halting the disease for laboratory animals.
- Compassionate Use Treatment
- For lymphocytic choriomeningitis (LCM), there are currently no specific antiviral treatments approved. However, in severe cases, ribavirin, an antiviral medication, has been used off-label. Compassionate use or experimental treatments are not well-established for LCM, and management primarily focuses on supportive care, such as pain relief, managing symptoms, and addressing complications. Patients with severe neurological complications may require hospitalization for more intensive support. Always consult a healthcare professional for the most appropriate care options.
- Lifestyle Recommendations
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For lymphocytic choriomeningitis (LCMV), the primary lifestyle recommendations focus on preventing exposure to the virus, which is commonly spread by rodents:
1. **Rodent Control**:
- Keep living spaces clean and free of food debris to deter rodents.
- Seal any holes or gaps in your home to prevent rodent entry.
- Use traps and rodenticide as needed, following safety instructions.
2. **Personal Hygiene**:
- Wash hands thoroughly with soap and water after handling pet rodents or cleaning rodent cages.
- Wear gloves when cleaning areas with rodent droppings or urine, and disinfect the area afterward.
3. **Pet Rodent Care**:
- Acquire pet rodents from reputable sources to minimize the risk of infection.
- Regularly clean and disinfect rodent cages and accessories.
4. **Avoiding Contact**:
- Avoid direct contact with wild rodents and their nesting materials.
By following these preventive measures, you can reduce the risk of contracting lymphocytic choriomeningitis. - Medication
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There is no specific antiviral treatment for lymphocytic choriomeningitis (LCM). Management primarily involves supportive care, which may include:
- Pain relievers for headache and muscle aches (e.g., acetaminophen)
- Antiemetics for nausea and vomiting
- Fluids for hydration
- Hospitalization in severe cases
In some instances, antiviral drugs like ribavirin have been used experimentally, but their efficacy is not well-established. It's essential to consult healthcare providers for appropriate management based on the severity of the illness. - Repurposable Drugs
- There is limited information on repurposable drugs specifically for lymphocytic choriomeningitis (LCM), which is caused by Lymphocytic Choriomeningitis Virus (LCMV). Management typically focuses on supportive care. However, antiviral drugs like ribavirin have been explored for viral hemorrhagic fevers and may have potential, although not specifically approved for LCM. Always consult a medical professional for the most current treatment options.
- Metabolites
- Lymphocytic choriomeningitis (LCM) primarily involves the lymphocytic choriomeningitis virus (LCMV). Information specifically on the metabolites associated with LCM is not well-documented in standard medical references. The disease is characterized by immune responses rather than specific metabolic disruptions, hence there's limited data on unique metabolites directly linked to LCMV infection.
- Nutraceuticals
- There is no established evidence to suggest that nutraceuticals are effective in the prevention or treatment of lymphocytic choriomeningitis (LCMV). Management typically focuses on supportive care and treating symptoms, as there is no specific antiviral therapy for this viral infection. Always consult healthcare professionals for appropriate diagnosis and treatment options.
- Peptides
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Lymphocytic choriomeningitis (LCM) is a viral infection caused by the lymphocytic choriomeningitis virus (LCMV). The virus is a rodent-borne arenavirus. For the term "peptides" in the context of LCM, it likely refers to the viral or host peptides involved in immune responses or the development of diagnostic tools and treatments. Specific peptides derived from LCMV proteins can be studied for their role in immune recognition and vaccine development.
If "nan" refers to nanotechnology, it encompasses the use of nanoscale materials and devices in the context of diagnosing, treating, or studying LCM. This might include the development of nanoparticles for targeted drug delivery, enhanced diagnostic techniques, or novel vaccine platforms leveraging nanoscale properties to improve efficacy and specificity against LCMV.