- Management of Patients With Suspected Viral Hemorrhagic Fever
- Viral hemorrhagic fever
- Ribavirin for Lassa Fever Postexposure Prophylaxis
- Lassa fever
- Ribavirin alone can’t cure Lassa fever —Scientists
Management of Patients With Suspected Viral Hemorrhagic FeverViral hemorrhagic fevers VHFs are a diverse group of animal and human illnesses in which fever and hemorrhage are caused by a viral infection. All types of VHF are characterized by fever and bleeding disorders and all can progress to high fever, shock and death in many cases. Some of the VHF agents cause relatively mild illnesses, such as the Scandinavian nephropathia epidemica a hantaviruswhile others, such as Ebola viruscan cause severe, life-threatening disease. Signs and symptoms of VHFs include by definition fever and bleeding. Manifestations of VHF often also include flushing of the face and chest, small red or purple spots petechiaebleeding, swelling caused by edemalow blood pressure hypotensionand shock. Malaisemuscle painheadache, vomiting, and diarrhea occur frequently. The severity of symptoms varies with the type of virus. The pathogen that caused the cocoliztli epidemics in Mexico of and is still unknown, and the epidemic may have been bacterial rather than viral. Different hemorrhagic fever viruses act on the body in different ways, resulting in different symptoms. In most VHFs, it is likely that several mechanisms contribute to symptoms, including liver damage, disseminated intravascular coagulation DICand bone marrow dysfunction. In DIC, small blood clots form in blood vessels throughout the body, removing platelets necessary for clotting from the bloodstream and reducing clotting ability. For filoviral hemorrhagic fevers, there are four general mechanisms of pathogenesis. The first mechanism is dissemination of virus due to suppressed responses by macrophages and dendritic cell antigen presenting cells. The second mechanism is prevention of antigen specific immune response. The third mechanism is apoptosis of lymphocytes. The fourth mechanism is when infected macrophages interact with toxic cytokinesleading to diapedesis and coagulation deficiency. From the vascular perspective, the virus will infect macrophages, leading to the reorganization of the VE-cadherin catenin complex a protein important in cell adhesion. This reorganization creates intercellular gaps in endothelial cells. The gaps lead to increased endothelial permeability and allow blood to escape from the vascular circulatory system. The reasons for variation among patients infected with the same virus are unknown but stem from a complex system of virus-host interactions. Dengue fever becomes more virulent during a second infection by means of antibody dependent enhancement. After the first infection, macrophages display antibodies on their cell membranes specific to the dengue virus. By attaching to these antibodies, dengue viruses from a second infection are better able to infect the macrophages, thus reducing the immune system's ability to fight off infection. Definitive diagnosis is usually made at a reference laboratory with advanced biocontainment capabilities. The findings of laboratory investigation vary somewhat between the viruses but in general there is a decrease in the total white cell count particularly the lymphocytesa decrease in the platelet count, an increase in the blood serum liver enzymesand reduced blood clotting ability measured as an increase in both the prothrombin PT and activated partial thromboplastin times PTT. The hematocrit may be elevated. The serum urea and creatine may be raised but this is dependent on the hydration status of the patient. The bleeding time tends to be prolonged.
Viral hemorrhagic fever
Lassa fever is an often fatal arenavirus infection that occurs mostly in West Africa. It may involve multiple organ systems. Diagnosis is with serologic tests and polymerase chain reaction PCR. Treatment includes IV ribavirin. The reservoir is the rats Mastomys natalensisM. The pygmy mouse Mus baoulei has recently been implicated as a reservoir species in West Africa, all of which commonly inhabit houses in Africa. Most human cases result from contamination of food with rodent urine, saliva, or feces, but human-to-human transmission can occur via exposure to the urine, feces, saliva, vomitus, or blood of infected people. Nosocomial human-to-human transmission is common when personal protective equipment is not available or not used. Based on serologic data, indigenous people in endemic areas have a very high rate of infection—much higher than their rate of hospitalization for Lassa fever—suggesting that many infections are mild and self-limited. However, some observational studies of missionaries sent to endemic areas show they have a much higher rate of severe illness and mortality. Symptoms of Lassa fever begin with gradually progressive fever, weakness, malaise, and gastrointestinal symptoms eg, nausea, vomiting, diarrhea, dysphagia, stomach ache ; symptoms and signs of hepatitis may occur. Over the subsequent 4 to 5 days, symptoms progress to prostration with sore throat, cough, chest pain, and vomiting. The sore throat becomes more severe during the first week; patches of white or yellow exudate may appear on the tonsils, often coalescing into a pseudomembrane. Occasionally, patients have tinnitus, epistaxis, bleeding from the gums and venipuncture sites, maculopapular rash, cough, and dizziness. Patients who recover defervesce in 4 to 7 days. Progression to severe illness results in shock, delirium, rales, pleural effusion, and, occasionally, generalized seizures. Pericarditis occasionally occurs. Degree of fever and aminotransferase levels correlate with disease severity. Lassa fever is suspected in patients with possible exposure if they have a viral prodrome followed by unexplained disease of any organ system. Liver tests, urinalysis, serologic tests, and possibly complete blood count should then be done. Proteinuria is common and may be massive. The most rapid diagnostic test is PCR, but demonstrating either Lassa IgM antibodies or a 4-fold rise in IgG antibody titer using an indirect fluorescent antibody technique is also diagnostic. Although the virus can be grown in cell culture, cultures are not routine. Because infection is a risk, particularly in patients with hemorrhagic fever, cultures must be handled only in a biosafety level 4 laboratory. Chest x-rays, obtained if lung involvement is suspected, may show basilar pneumonitis and pleural effusions. Recovery or death usually occurs 7 to 31 days average 12 to 15 days after symptoms begin. Disease is severe during pregnancy, especially during the 3rd trimester. Most infected pregnant women lose the fetus. Ribavirinif begun within the first 6 days, may reduce mortality up to fold. Anti-Lassa fever plasma has been tried in very ill patients but has not been shown to be beneficial and is not currently recommended. Universal precautions, including use of personal preventive equipment and other measures for airborne isolation eg, use of goggles, high-efficiency masks, a negative-pressure room, positive-pressure filtered air respiratorsand surveillance of contacts are recommended when treating patients with Lassa fever. Guidelines for cleaning up after rodents and working in areas with potential rodent excreta are available from the Centers for Disease Control and Prevention CDC. Lassa fever is usually transmitted by consuming food contaminated with rodent excreta, but human-to-human transmission can occur via infected urine, feces, saliva, vomitus, or blood. Symptoms may progress from fever, weakness, malaise, and gastrointestinal symptoms to prostration with sore throat, cough, chest pain, and vomiting; sometimes to shock, delirium, rales, and pleural effusion; and occasionally to severe illness and shock. Ribavirinif begun within the first 6 days, may reduce mortality up to fold; supportive treatment, including correction of fluid and electrolyte imbalances, is imperative.
Ribavirin for Lassa Fever Postexposure Prophylaxis
Persons using assistive technology might not be able to fully access information in this file. For assistance, please send e-mail to: mmwrq cdc. Type Accommodation and the title of the report in the subject line of e-mail. The term viral hemorrhagic fever VHF refers to the illness associated with a number of geographically restricted viruses. This illness is characterized by fever and, in the most severe cases, shock and hemorrhage 1. Although a number of other febrile viral infections may produce hemorrhage, only the agents of Lassa, Marburg, Ebola, and Crimean-Congo hemorrhagic fevers are known to have caused significant outbreaks of disease with person-to-person transmission. Therefore, the following recommendations specifically address these four agents. The increasing volume of international travel, including visits to rural areas of the tropical world, provides opportunity for the importation of these infections into countries with no endemic VHF, such As the United States. Since most physicians have little or no experience with these viruses, uncertainty often arises when VHF is a diagnostic possibility. Lassa, Marburg, and Ebola viruses are restricted to sub-Saharan Africa, and the differential diagnosis of VHF will most often be made for illness in travelers to this region. Sinceno imported cases of VHF have been confirmed in the United States, but every year there are approximately five to 10 suspected cases. These guidelines review the clinical and epidemiologic features of these diseases; provide recommendations on diagnosis, investigation, and care of patients; and suggest measures to prevent secondary transmission. This document updates earlier recommendations, issued in 2for the management of suspected and confirmed cases of VHF. Accumulated evidence shows that transmission of these viruses does not occur through casual contact; thus, some earlier recommendations for preventing secondary transmission have been relaxed. Similarly, therapy recommendations have taken into account recent knowledge of the effects of antiviral drugs. Further information on investigating and managing patients with suspected VHF, collecting and shipping diagnostic specimens, and instituting control measures is available on request from the following persons at CDC in Atlanta, Georgia. McCormick, M. Fisher-Hoch, M. After regular office hours and on weekends, the persons named above may be contacted through the CDC duty officer ext. Lassa virus, named after a small town in northeastern Nigeria, is an enveloped, single-stranded, bisegmented ribonucleic acid RNA virus classified in the family Arenaviridae. Its natural host is the multimammate rat Mastomys natalensis. This ubiquitous African rodent lives in close association with humans and is commonly found in and around houses in rural areas. The rats are infected throughout life and shed high levels of virus in their urine. Although the rodent reservoir exists across wide areas of Africa, Lassa virus appears to be restricted to the continent's western part. Closely related viruses are found in other areas, but their potential for causing human disease is poorly understood. Lassa fever was first recognized in in northern Nigeria 3 when two of three nurses infected in a rural hospital died.
Contrary to what the National Centre for Disease Control wants Nigerians to believe, Ribavirin, the only drug currently being used in the treatment of Lassa fever, does not suppress viral transmission, viral production, or enhance immune response. Ribavirin only efficiently suppresses the replication of Lassa virus in vitro in a test tubeand shows only moderate efficacy in reducing presence of viruses in the blood in a living organism. Writing about the disease, the scientists said, clinically, Lassa fever is difficult to distinguish from other endemic febrile illnesses in West Africa, noting that its symptoms include fever, pharyngitis, gastrointestinal complaints, and cough. Workers stitch medical clothing and protective gear at a small factory in Peshawar, Pakistan, on April 8, Turkish and Russian armored vehicles are seen during the third Turkish-Russian joint land patrol at M4 road in Idlib, Syria, on April 8, Navy music band play outside a housing complex in an effort to boost morale in Colombo, Sri Lanka, on April 8, Policemen stand guard during an operation to ensure the curfew declared by the government in El Callao, Peru, on April 8, A riot police officer demands a clearance letter to be on the road from a water delivery truck driver, in Harare, Zimbabwe, on April 8, A man walks past a line of people waiting to collect their pension in La Paz, Bolivia, on April 8, The SRC increased their employees to meet the increased demand on ambulances since the novel coronavirus appeared and the kingdom imposed a curfew. A man works from his home while his wife is seen playing a video game during a two-week curfew, as part of the Egyptian government's plan to contain the spread of COVID, in Cairo, Egypt, on April 6, Police officers control civilians during a total lockdown amid concerns about the spread of the coronavirus disease, in Kinshasa, Democratic Republic of Congo, on April 6, People reach for a bag of food thrown from a truck at a distribution run by a Haitian government program amid the spread of the coronavirus disease, in Port-au-Prince, Haiti, on April 6, A hawker sells masks on street during the government-imposed lockdown in Dhaka, Bangladesh, on April 6, A journalist talks to the camera on Paseo de la Reforma avenue as the coronavirus disease continues in Mexico City, Mexico, on April 6, Performers wear masks as a precaution against coronavirus on Charles Bridge in Prague, Czech Republic, on April 6, Police officers wear gloves and face masks as they stand guard in a street of Santiago, Chile, on April 6,amid the coronavirus pandemic. A woman wearing a protective mask signs documents to register as an unemployed in front of a local labor office in Sofia, Bulgaria, on April 6, Men build a booth that will help health workers to test COVID patients safely during the 14th day of the lockdown imposed by the government, in Bhaktapur, Nepal, on April 6, People are seen praying outside a church on the occasion of Palm Sunday in Kampala, Uganda, on April 5, A staff from German embassy checks passenger's passports as they wait for a flight back home, at Tribhuvan International Airport in Kathmandu, Nepal, on April 4, A group of women are seen at the street in Lima, Peru, on April 4,