71-467: Marburg virus disease ( MVD ), formerly Marburg hemorrhagic fever ( MHF ) is a viral hemorrhagic fever in human and non-human primates caused by either of the two Marburgviruses : Marburg virus (MARV) and Ravn virus (RAVV). Its clinical symptoms are very similar to those of Ebola virus disease (EVD). Egyptian fruit bats are believed to be the normal carrier in nature and Marburg virus RNA has been isolated from them. The most detailed study on
142-752: A nurse , a post-mortem attendant, and the wife of a veterinarian . All secondary cases had direct contact, usually involving blood, with a primary case. Both physicians became infected through accidental skin pricks when drawing blood from patients. In 1975, an Australian tourist became infected with MARV in Rhodesia (today Zimbabwe ). He died in a hospital in Johannesburg , South Africa . His girlfriend and an attending nurse were subsequently infected with MVD, but survived. A case of MARV infection occurred in 1980 in Kenya . A French man, who worked as an electrical engineer in
213-625: A 10-amino-acid insertion in ribosomal protein L19, a one-amino-acid insertion in FtsZ , a one-amino-acid insertion in major sigma factor 70, and a one-amino-acid deletion in exonuclease VII . These indels are all characteristic of the genus and serve as molecular markers for Rickettsia . Bacterial small RNAs play critical roles in virulence and stress/adaptation responses. Although their specific functions have not been discovered in Rickettsia , few studies showed
284-467: A basis for fighting HIV infection. Human immune response to the scrub typhus pathogen, Orientia tsutsugamushi , appears to provide a beneficial effect against HIV infection progress, negatively influencing the virus replication process. A probable reason for this actively studied phenomenon is a certain degree of homology between the rickettsiae and the virus, namely, common epitope (s) due to common genome fragment(s) in both pathogens. Surprisingly,
355-742: A case of bacterial meningitis in a woman caused by Rickettsia helvetica previously thought to be harmless. Magnetococcus marinus Holosporales Hyphomicrobiales , Rhodobacteraceae , Rhodospirillales , Sphingomonadales , etc . Pelagibacter Subgroups Ib, II, IIIa, IIIb, IV and V Proto-mitochondria Neorickettsia Wolbachia Anaplasma Ehrlichia Midichloria Orientia Rickettsia Plant diseases have been associated with these Rickettsia -like organisms (RLOs): Infection occurs in nonhuman mammals; for example, species of Rickettsia have been found to afflict
426-671: A case of the Marburg disease was confirmed by health authorities through laboratory analysis. Other potential case of the disease in a contact awaits official results. This was the first case of the Marburg hemorrhagic fever confirmed to happen in West Africa. The case of Marburg also has been identified in Guéckédou . During the outbreak, a total of one confirmed case, who died ( CFR =100%), and 173 contacts were identified, including 14 high-risk contacts based on exposure. Among them, 172 were followed for
497-414: A decrease in the platelet count, an increase in the blood serum liver enzymes , and 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. With
568-490: A gown at all times). Traditional burial rituals, especially those requiring embalming of bodies, should be discouraged or modified, ideally with the help of local traditional healers . Marburgviruses are World Health Organization Risk Group 4 Pathogens, requiring Biosafety Level 4-equivalent containment , laboratory researchers have to be properly trained in BSL-4 practices and wear proper personal protective equipment. There
639-412: A health care worker – developed symptoms on 4 November and was admitted to a hospital. The first confirmed case traveled to Kenya before the death. A close contact of the second confirmed case traveled to Kampala . It is reported that several hundred people may have been exposed to infection. In August 2021, two months after the re-emergent Ebola epidemic in the Guéckédou prefecture was declared over,
710-533: A hospital on July 7, and died on July 13. Contact tracing revealed that the man had had prolonged close contact with two colleagues (a 22-year-old man and a 23-year-old man), who experienced clinical signs of infection before his disease onset. Both men had been admitted to hospitals in June and survived their infections, which were proven to be due to MARV. A fourth, 25-year-old man, developed MVD clinical signs in September and
781-405: A minimum, a fit-tested , HEPA filter-equipped respirator (such as an N95 mask ), a battery-powered, air-purifying respirator, or a positive pressure supplied air respirator to be worn by personnel coming within 1.8 meter (six feet) of a VHF patient. Groups of patients should be cohorted (sequestered) to a separate building or a ward with an isolated air-handling system. Environmental decontamination
SECTION 10
#1732855050355852-586: A period of 21 days, of which none developed symptoms. One high-risk contact was lost to follow up. Sequencing of an isolate from the Guinean patient showed that this outbreak was caused by the Angola-like Marburg virus. A colony of Egyptian rousettus bats ( reservoir host of Marburg virus ) was found in close proximity (4.5 km) to the village, where the Marburg virus disease outbreak emerged in 2021. Two sampled fruit bats from this colony were PCR-positive on
923-413: 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 lymphocytes ),
994-478: A shortage of basic personal protective equipment . Médecins Sans Frontières (MSF) reported that when their team arrived at the provincial hospital at the center of the outbreak, they found it operating without water and electricity. Contact tracing was complicated by the fact that the country's roads and other infrastructure were devastated after nearly three decades of civil war and the countryside remained littered with land mines . Americo Boa Vida Hospital in
1065-593: A sugar factory in Nzoia (close to Bungoma ) at the base of Mount Elgon (which contains Kitum Cave ), became infected by unknown means and died on 15 January shortly after admission to Nairobi Hospital. The attending physician contracted MVD, but survived. A popular science account of these cases can be found in Richard Preston 's book The Hot Zone (the French man is referred to under the pseudonym "Charles Monet", whereas
1136-593: A suspected case of Marburg was reported in the Spanish city of Valencia , however this case was subsequently discounted. As of 4 April 2023, there were 14 confirmed cases and 28 suspected cases, including ten confirmed deaths from the disease in Equatorial Guinea. On 8 June 2023, the World Health Organization declared the outbreak over. In total, 17 laboratory-confirmed cases and 12 deaths were recorded. All
1207-411: Is 1,111,523 bp long and contains 834 genes . Unlike free-living bacteria, it contains no genes for anaerobic glycolysis or genes involved in the biosynthesis and regulation of amino acids and nucleosides . In this regard, it is similar to mitochondrial genomes; in both cases, nuclear (host) resources are used. ATP production in Rickettsia is the same as that in mitochondria. In fact, of all
1278-508: Is a genus of nonmotile , gram-negative , nonspore-forming , highly pleomorphic bacteria that may occur in the forms of cocci (0.1 μm in diameter), bacilli (1–4 μm long), or threads (up to about 10 μm long). The genus was named after Howard Taylor Ricketts in honor of his pioneering work on tick-borne spotted fever . Properly, Rickettsia is the name of a single genus, but the informal term "rickettsia", plural "rickettsias," usually not capitalised, commonly applies to any members of
1349-508: Is clinically indistinguishable from Ebola virus disease (EVD) , and it can also easily be confused with many other diseases prevalent in Equatorial Africa , such as other viral hemorrhagic fevers , falciparum malaria , typhoid fever , shigellosis , rickettsial diseases such as typhus , cholera , gram-negative sepsis , borreliosis such as relapsing fever or EHEC enteritis . Other infectious diseases that ought to be included in
1420-625: Is currently no effective marburgvirus-specific therapy for MVD. Treatment is primarily supportive in nature and includes minimizing invasive procedures, balancing fluids and electrolytes to counter dehydration , administration of anticoagulants early in infection to prevent or control disseminated intravascular coagulation , administration of procoagulants late in infection to control hemorrhaging , maintaining oxygen levels, pain management , and administration of antibiotics or antifungals to treat secondary infections. Although supportive care can improve survival chances, marburg virus disease
1491-605: Is fatal in the majority of cases. As of 2023 the case fatality rate was assessed to be 61.9%. The WHO identifies marburg virus disease as having pandemic potential. Below is a table of outbreaks concerning MVD from 1967 to 2024: MVD was first documented in 1967, when 31 people became ill in the German towns of Marburg and Frankfurt am Main , and in Belgrade , Yugoslavia . The outbreak involved 25 primary MARV infections and seven deaths, and six nonlethal secondary cases. The outbreak
SECTION 20
#17328550503551562-589: Is highly recommended, but may not be possible for those working in mines or people dependent on bats as a food source. Since marburgviruses are not spread via aerosol, the most straightforward prevention method during MVD outbreaks is to avoid direct (skin-to-skin) contact with patients, their excretions and body fluids , and any possibly contaminated materials and utensils. Patients should be isolated, but still are safe to be visited by family members. Medical staff should be trained in and apply strict barrier nursing techniques (disposable face mask, gloves, goggles, and
1633-584: Is named after Howard Taylor Ricketts (1871–1910), who studied Rocky Mountain spotted fever in the Bitterroot Valley of Montana, and eventually died of typhus after studying that disease in Mexico City. In his early part of career, he undertook research at Northwestern University on blastomycosis. He later worked on Rocky Mountain spotted fever at the University of Chicago and Bitterroot Valley of Montana. He
1704-443: Is not the cause of death (total blood loss is minimal except during labor ). Instead, death occurs due to multiple organ dysfunction syndrome (MODS) due to fluid redistribution, hypotension , disseminated intravascular coagulation , and focal tissue necroses . Clinical phases of Marburg hemorrhagic fever's presentation are described below. Note that phases overlap due to variability between cases. The WHO also writes that at
1775-511: Is not yet an approved vaccine, because of economic factors in vaccine development , and because filoviruses killed few before the 2010s. The natural maintenance hosts of marburgviruses remain to be identified unequivocally. However, the isolation of both MARV and RAVV from bats and the association of several MVD outbreaks with bat-infested mines or caves strongly suggests that bats are involved in Marburg virus transmission to humans. Avoidance of contact with bats and abstaining from visits to caves
1846-631: Is prevention of antigen specific immune response. The third mechanism is apoptosis of lymphocytes. The fourth mechanism is when infected macrophages interact with toxic cytokines , leading to diapedesis and coagulation deficiency. From the vascular perspective, the virus will infect vascular endothelial cells, 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
1917-956: Is publicly available about this MVD case because Ustinov's experiments were classified. A popular science account of this case can be found in Ken Alibek 's book Biohazard . Another laboratory accident occurred at the Scientific-Production Association "Vektor" (today the State Research Center of Virology and Biotechnology "Vektor" ) in Koltsovo , USSR , when a scientist contracted MARV by unknown means. A major MVD outbreak occurred among illegal gold miners around Goroumbwa mine in Durba and Watsa , Democratic Republic of Congo from 1998 to 2000, when co-circulating MARV and RAVV caused 154 cases of MVD and 128 deaths. The outbreak ended with
1988-430: Is referred to under the pseudonym "Peter Cardinal"). In 1988, researcher Nikolai Ustinov infected himself lethally with MARV after accidentally pricking himself with a syringe used for inoculation of guinea pigs . The accident occurred at the Scientific-Production Association "Vektor" (today the State Research Center of Virology and Biotechnology "Vektor" ) in Koltsovo , USSR (today Russia ). Very little information
2059-480: Is typically accomplished with hypochlorite (e.g. bleach) or phenolic disinfectants . Medical management of VHF patients may require intensive supportive care. Antiviral therapy with intravenous ribavirin may be useful in Bunyaviridae and Arenaviridae infections (specifically Lassa fever, RVF, CCHF, and HFRS due to Old World Hantavirus infection) and can be used only under an experimental protocol as IND approved by
2130-681: The Bunyavirales order such as Arenaviridae , and Hantaviridae . 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 hantavirus ), while others, such as Ebola virus , can cause severe, life-threatening disease. Signs and symptoms of VHFs include (by definition) fever and bleeding: The severity of symptoms varies with
2201-645: The Leiden University Medical Centre in Leiden on July 11. The Ugandan Ministry of Health closed the cave after this case. On January 9 of that year an infectious diseases physician notified the Colorado Department of Public Health and the Environment that a 44-year-old American woman who had returned from Uganda had been hospitalized with a fever of unknown origin . At the time, serologic testing
Marburg virus disease - Misplaced Pages Continue
2272-514: The South American guanaco , Lama guanacoe potentially marsupials and reptiles. Rickettsial organisms are obligate intracellular parasites and invade vascular endothelial cells in target organs, damaging them and producing increased vascular permeability with consequent oedema , hypotension , and hypoalbuminaemia . Certain segments of rickettsial genomes resemble those of mitochondria . The deciphered genome of R. prowazekii
2343-545: The U.S. Food and Drug Administration (FDA). Interferon may be effective in Argentine or Bolivian hemorrhagic fevers (also available only as IND). The VHF viruses are spread in a variety of ways. Some may be transmitted to humans through a respiratory route. The viruses are considered by military medical planners to have a potential for aerosol dissemination, weaponization, or likelihood for confusion with similar agents that might be weaponized. Rickettsia Rickettsia
2414-528: The cocoliztli epidemics in Mexico of 1545 and 1576 is still unknown, and the 1545 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 (DIC), and bone marrow dysfunction. In DIC, small blood clots form in blood vessels throughout
2485-614: The differential diagnosis include leptospirosis , scrub typhus , plague , Q fever , candidiasis , histoplasmosis , trypanosomiasis , visceral leishmaniasis , hemorrhagic smallpox , measles , and fulminant viral hepatitis . Non-infectious diseases that can be confused with MVD are acute promyelocytic leukemia , hemolytic uremic syndrome , snake envenomation , clotting factor deficiencies/platelet disorders, thrombotic thrombocytopenic purpura , hereditary hemorrhagic telangiectasia , Kawasaki disease , and even warfarin intoxication. The most important indicator that may lead to
2556-442: The tetracycline group. The classification of Rickettsia into three groups (spotted fever, typhus, and scrub typhus ) was initially based on serology . This grouping has since been confirmed by DNA sequencing . All three of these groups include human pathogens . The scrub typhus group has been reclassified as a related new genus, Orientia , but they still are in the order Rickettsiales and accordingly still are grouped with
2627-520: The 23 probable cases reportedly died. Four patients recovered from the virus and have been enrolled in a survivors programme to receive psychosocial and other post-recovery support. A Marburg virus disease outbreak in Tanzania was first reported on 21 March 2023 by the Ministry of Health of Tanzania. This was the first time that Tanzania had reported an outbreak of the disease. On 2 June 2023, Tanzania declared
2698-496: The Angolan capital, Luanda , set up a special isolation ward to treat patients from the countryside. Due to the high fatality rate of MVD, some people came to be suspicious of and hostile towards hospitals and medical workers. For instance, a specially-equipped isolation ward at the provincial hospital in Uíge was reported to be empty during much of the epidemic, even though the facility was at
2769-456: The MARV genome New therapies from Sarepta and Tekmira have also been successfully used in humans as well as primates. Viral hemorrhagic fever Viral hemorrhagic fevers ( VHFs ) are a diverse group of animal and human illnesses . VHFs may be caused by five distinct families of RNA viruses : the families Filoviridae , Flaviviridae , Rhabdoviridae , and several member families of
2840-525: The Marburg virus. In July 2022, preliminary analysis of samples taken from two patients – both deceased – in Ghana indicated the cases were positive for Marburg. However, per standard procedure, the samples were sent to the Pasteur Institute of Dakar for confirmation. On 17 July 2022 the two cases were confirmed by Ghana, which caused the country to declare a Marburg virus disease outbreak. An additional case
2911-462: The actual hosts of MARV and RAVV or whether they get infected via contact with another animal and therefore serve only as intermediate hosts. Another risk factor is contact with nonhuman primates, although only one outbreak of MVD (in 1967) was due to contact with infected monkeys. Contrary to Ebola virus disease (EVD) , which has been associated with heavy rains after long periods of dry weather, triggering factors for spillover of marburgviruses into
Marburg virus disease - Misplaced Pages Continue
2982-460: The acute phase of MVD. Marburgvirus isolation is usually performed by inoculation of grivet kidney epithelial Vero E6 or MA-104 cell cultures or by inoculation of human adrenal carcinoma SW-13 cells, all of which react to infection with characteristic cytopathic effects . Filovirions can easily be visualized and identified in cell culture by electron microscopy due to their unique filamentous shapes, but electron microscopy cannot differentiate
3053-479: The body, removing platelets necessary for clotting from the bloodstream and reducing clotting ability. DIC is thought to cause bleeding in Rift Valley, Marburg, and Ebola fevers. 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
3124-471: The center of the outbreak. WHO was forced to implement what it described as a "harm reduction strategy" by distributing disinfectants to affected families who refused hospital care. Of the 252 people who contracted MVD, 227 died. In 2007, four miners became infected with marburgviruses in Kamwenge District , Uganda . The first case, a 29-year-old man, became symptomatic on July 4, 2007, was admitted to
3195-419: The country. Experimentally, recombinant vesicular stomatitis Indiana virus (VSIV) expressing the glycoprotein of MARV has been used successfully in nonhuman primate models as post-exposure prophylaxis. A vaccine candidate has been effective in nonhuman primates. Experimental therapeutic regimens relying on antisense technology have shown promise, with phosphorodiamidate morpholino oligomers (PMOs) targeting
3266-616: The current view in rickettsiology has a strong anthropocentric bias. Pathogenic Rickettsia species are transmitted by numerous types of arthropods , including chiggers , ticks , fleas , and lice , and are associated with both human and plant diseases. Most notably, Rickettsia species are the pathogens responsible for typhus , rickettsialpox , boutonneuse fever , African tick-bite fever , Rocky Mountain spotted fever , Flinders Island spotted fever , and Queensland tick typhus ( Australian tick typhus). The majority of pathogenic Rickettsia bacteria are susceptible to antibiotics of
3337-490: The early 1930s. Many new strains or species of Rickettsia are described each year. Some Rickettsia species are pathogens of medical and veterinary interest, but many Rickettsia are non-pathogenic to vertebrates, including humans, and infect only arthropods, often non-hematophagous, such as aphids or whiteflies. Many Rickettsia species are thus arthropod-specific symbionts, but are often confused with pathogenic Rickettsia (especially in medical literature), showing that
3408-654: The exception of yellow fever vaccine and Ebola vaccines , vaccines for VHF-associated viruses are generally not available. Post-exposure prophylactic (preventive) ribavirin may be effective for some bunyavirus and arenavirus infections. VHF isolation guidelines dictate that all VHF patients (with the exception of dengue patients) should be cared for using strict contact precautions, including hand hygiene, double gloves, gowns, shoe and leg coverings, and face shield or goggles. Lassa, CCHF, Ebola, and Marburg viruses may be particularly prone to nosocomial (hospital-based) spread. Airborne precautions should be utilized including, at
3479-456: The expression of novel sRNA in human microvascular endothelial cells (HMEC) infected with Rickettsia . Genomes of intracellular or parasitic bacteria undergo massive reduction compared to their free-living relatives. Examples include Rickettsia for alpha proteobacteria, T. whipplei for Actinobacteria, Mycoplasma for Firmicutes (the low G+C content Gram-positive), and Wigglesworthia and Buchnera for gamma proteobacteria. The genus Rickettsia
3550-433: The field anymore. Marburg virus disease (MVD) is the official name listed in the World Health Organization 's International Statistical Classification of Diseases and Related Health Problems 10 (ICD-10) for the human disease caused by any of the two marburgviruses; Marburg virus (MARV) and Ravn virus (RAVV). In the scientific literature, Marburg hemorrhagic fever (MHF) is often used as an unofficial alternative name for
3621-507: The flooding of the mine. In early 2005, the World Health Organization (WHO) began investigating an outbreak of viral hemorrhagic fever in Angola , which was centered in the northeastern Uíge Province but also affected many other provinces. The Angolan government had to ask for international assistance, as there were only approximately 1,200 doctors in the entire country and provinces that had few as two. Health care workers also complained about
SECTION 50
#17328550503553692-403: The frequency, onset, and duration of MVD clinical signs and symptoms was performed during the 1998–2000 mixed MARV/RAVV disease outbreak. A skin rash , red or purple spots (e.g. petechiae or purpura ), bruises , and hematomas (especially around needle injection sites) are typical hemorrhagic manifestations. However, contrary to popular belief, hemorrhage does not lead to hypovolemia and
3763-632: The human population have not yet been described. The details of the initial transmission of MVD to humans remain incompletely understood. Transmission most likely occurs from Egyptian fruit bats or another natural host, such as non-human primates or through the consumption of bushmeat , but the specific routes and body fluids involved are unknown. Human-to-human transmission of MVD occurs through direct contact with infected bodily fluids such as blood. Transmission events are relatively rare – there have been only 11 recorded outbreaks of MARV between 1975 and 2011, with one event involving both MARV and RAVV. MVD
3834-548: The microbes known, the Rickettsia is probably the closest relative (in a phylogenetic sense) to the mitochondria. Unlike the latter, the genome of R. prowazekii , however, contains a complete set of genes encoding for the tricarboxylic acid cycle and the respiratory chain complex. Still, the genomes of the Rickettsia , as well as the mitochondria, are frequently said to be "small, highly derived products of several types of reductive evolution". The recent discovery of another parallel between Rickettsia and viruses may become
3905-492: The order Rickettsiales . Being obligate intracellular bacteria , rickettsias depend on entry, growth, and replication within the cytoplasm of living eukaryotic host cells (typically endothelial cells). Accordingly, Rickettsia species cannot grow in artificial nutrient culture; they must be grown either in tissue or embryo cultures. Mostly chicken embryos are used, following a method developed by Ernest William Goodpasture and his colleagues at Vanderbilt University in
3976-421: The other infection reported to be likely to provide the same effect (decrease in viral load) is the virus-caused illness dengue fever . Comparative analysis of genomic sequences have also identified five conserved signature indels in important proteins, which are uniquely found in members of the genus Rickettsia . These indels consist of a four-amino-acid insertion in transcription repair coupling factor Mfd,
4047-549: The outbreak over. There were 9 total infections, resulting in 6 total deaths. On September 27, 2024, an outbreak of the Marburg virus was confirmed in Rwanda . As of September 29, 2024, six deaths and twenty cases had been confirmed. The Rwandan Minister of Health, Sabin Nsanzimana , confirmed that the infected were mostly healthcare workers and that contact tracing had been initiated in
4118-503: The phase of gastrointestinal symptoms' predomination, "the appearance of patients...has been described as showing 'ghost-like' drawn features, deep-set eyes, expressionless faces, and extreme lethargy." MVD is caused by two viruses; Marburg virus (MARV) and Ravn virus (RAVV) , family Filoviridae. Marburgviruses are endemic in arid woodlands of equatorial Africa . Most marburgvirus infections were repeatedly associated with people visiting natural caves or working in mines . In 2009,
4189-527: The physician is identified under his real name, Shem Musoke). In 1987, a single lethal case of RAVV infection occurred in a 15-year-old Danish boy, who spent his vacation in Kisumu , Kenya . He had visited Kitum Cave on Mount Elgon prior to travelling to Mombasa , where he developed clinical signs of infection. The boy died after transfer to Nairobi Hospital. A popular science account of this case can be found in Richard Preston 's book The Hot Zone (the boy
4260-446: The prevention of MVD. Many candidate vaccines have been developed and tested in various animal models. Of those, the most promising ones are DNA vaccines or based on Venezuelan equine encephalitis virus replicons , vesicular stomatitis Indiana virus (VSIV) or filovirus-like particles (VLPs) as all of these candidates could protect nonhuman primates from marburgvirus-induced disease. DNA vaccines have entered clinical trials. There
4331-489: The rest of the rickettsial diseases. Rickettsias are more widespread than previously believed and are known to be associated with arthropods , leeches , and protists . Divisions have also been identified in the spotted fever group and this group likely should be divided into two clades . Arthropod-inhabiting rickettsiae are generally associated with reproductive manipulation (such as parthenogenesis ) to persist in host lineage. In March 2010, Swedish researchers reported
SECTION 60
#17328550503554402-563: The same disease. Both disease names are derived from the German city Marburg , where MARV was first discovered. Marburgviruses are highly infectious , but not very contagious . They do not get transmitted by aerosol during natural MVD outbreaks. Due to the absence of an approved vaccine, prevention of MVD therefore relies predominantly on quarantine of confirmed or high probability cases, proper personal protective equipment , and sterilization and disinfection . There are currently no Food and Drug Administration -approved vaccines for
4473-404: The successful isolation of infectious MARV and RAVV was reported from healthy Egyptian fruit bat caught in caves. This isolation strongly suggests that Old World fruit bats are involved in the natural maintenance of marburgviruses and that visiting bat-infested caves is a risk factor for acquiring marburgvirus infections. Further studies are necessary to establish whether Egyptian rousettes are
4544-427: The suspicion of MVD at clinical examination is the medical history of the patient, in particular the travel and occupational history (which countries and caves were visited?) and the patient's exposure to wildlife (exposure to bats or bat excrements?). MVD can be confirmed by isolation of marburgviruses from or by detection of marburgvirus antigen or genomic or subgenomic RNAs in patient blood or serum samples during
4615-538: The type of virus. The "VHF syndrome" (capillary leak, bleeding diathesis , and circulatory compromise leading to shock) appears in a majority of people with filoviral hemorrhagic fevers (e.g., Ebola and Marburg virus ), Crimean–Congo hemorrhagic fever (CCHF), and the South American hemorrhagic fevers caused by arenaviruses , but only in a small minority of patients with dengue or Rift Valley fever . Five families of RNA viruses have been recognised as being able to cause hemorrhagic fevers. The pathogen that caused
4686-509: The various filoviruses alone despite some overall length differences. Immunofluorescence assays are used to confirm marburgvirus presence in cell cultures. During an outbreak, virus isolation and electron microscopy are most often not feasible options. The most common diagnostic methods are therefore RT-PCR in conjunction with antigen-capture ELISA , which can be performed in field or mobile hospitals and laboratories. Indirect immunofluorescence assays (IFAs) are not used for diagnosis of MVD in
4757-451: 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
4828-470: Was identified, bringing the total to three. A disease outbreak was first reported in Equatorial Guinea on 7 February 2023, and on 13 February 2023, it was identified as being Marburg virus disease. It was the first time the disease was detected in the country. Neighbouring Cameroon detected two suspected cases of Marburg virus disease on 13 February 2023, but they were later ruled out. On 25 February,
4899-649: Was negative for viral hemorrhagic fever . She was discharged on January 19, 2008. After the death of the Dutch patient and the discovery that the American woman had visited Python Cave, further testing confirmed the patient demonstrated MARV antibodies and RNA . In October 2017 an outbreak of Marburg virus disease was detected in Kween District , Eastern Uganda. All three initial cases (belonging to one family – two brothers and one sister) had died by 3 November. The fourth case –
4970-643: Was shown to be infected with RAVV. He also survived the infection. On July 10, 2008, the Netherlands National Institute for Public Health and the Environment reported that a 41-year-old Dutch woman, who had visited Python Cave in Maramagambo Forest during her holiday in Uganda , had MVD due to MARV infection, and had been admitted to a hospital in the Netherlands . The woman died under treatment in
5041-808: Was traced to infected grivets (species Chlorocebus aethiops ) imported from an undisclosed location in Uganda and used in developing poliomyelitis vaccines . The monkeys were received by Behringwerke, a Marburg company founded by the first winner of the Nobel Prize in Medicine , Emil von Behring . The company, which at the time was owned by Hoechst , was originally set up to develop sera against tetanus and diphtheria . Primary infections occurred in Behringwerke laboratory staff while working with grivet tissues or tissue cultures without adequate personal protective equipment . Secondary cases involved two physicians ,
#354645