Lassa fever, also known as Lassa hemorrhagic fever, is a type of viral hemorrhagic fever caused by the Lassa virus. Many of those infected by the virus do not develop symptoms. When symptoms occur they typically include fever, weakness, headaches, vomiting, and muscle pains. Less commonly there may be bleeding from the mouth or gastrointestinal tract. The risk of death once infected is about one percent and frequently occurs within two weeks of the onset of symptoms. Of those who survive, about a quarter have hearing loss, which improves within three months in about half of these cases.
Bartonella is a genus of Gram-negative bacteria. It is the only genus in the family Bartonellaceae. Facultative intracellular parasites, Bartonella species can infect healthy people, but are considered especially important as opportunistic pathogens. Bartonella species are transmitted by vectors such as fleas, sand flies, and mosquitoes. At least eight Bartonella species or subspecies are known to infect humans.
Lassa mammarenavirus (LASV) is an arenavirus that causes Lassa hemorrhagic fever, a type of viral hemorrhagic fever (VHF), in humans and other primates. Lassa mammarenavirus is an emerging virus and a select agent, requiring Biosafety Level 4-equivalent containment. It is endemic in West African countries, especially Sierra Leone, the Republic of Guinea, Nigeria, and Liberia, where the annual incidence of infection is between 300,000 and 500,000 cases, resulting in 5,000 deaths per year.
An arenavirus is a bi- or trisegmented ambisense RNA virus that is a member of the family Arenaviridae. These viruses infect rodents and occasionally humans. A class of novel, highly divergent arenaviruses, properly known as reptarenaviruses, have also been discovered which infect snakes to produce inclusion body disease, mostly in boa constrictors. At least eight arenaviruses are known to cause human disease. The diseases derived from arenaviruses range in severity. Aseptic meningitis, a severe human disease that causes inflammation covering the brain and spinal cord, can arise from the lymphocytic choriomeningitis virus. Hemorrhagic fever syndromes, including Lassa fever, are derived from infections such as Guanarito virus, Junin virus, Lassa virus, Lujo virus, Machupo virus, Sabia virus, or Whitewater Arroyo virus. Because of the epidemiological association with rodents, some arenaviruses and bunyaviruses are designated as roboviruses.
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 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, while others, such as Ebola virus, can cause severe, life-threatening disease.
Venezuelan hemorrhagic fever (VHF) is a zoonotic human illness first identified in 1989. The disease is most prevalent in several rural areas of central Venezuela and is caused by Guanarito mammarenavirus (GTOV) which belongs to the Arenaviridae family. The short-tailed cane mouse is the main host for GTOV which is spread mostly by inhalation of aerosolized droplets of saliva, respiratory secretions, urine, or blood from infected rodents. Person-to-person spread is possible, but uncommon.
Lobomycosis is a fungal infection of the skin. It usually presents with bumps in the skin, firm swellings, deep skin lesions, or malignant tumors.
The Awash multimammate mouse or Awash mastomys is a species of rodent in the family Muridae found only in Ethiopia. Phylogentically the Awash multimammate mouse is the sister taxon of the Natal multimammate mouse, a species found almost everywhere in Africa south of the Sahara and considered a serious agricultural pest throughout its range.
Mastomys is a genus of rodent in the family Muridae endemic to Africa. It contains eight species:
The southern multimammate mouse or southern African mastomys is a species of rodent in the family Muridae which is endemic to southern Africa. It is called a multimammate mouse because it can have 8 to 12 pairs of mammae, in comparison other mouse species only have 5 pairs.
The Natal multimammate mouse is a species of rodent in the family Muridae. It is also known as the Natal multimammate rat, the common African rat, or the African soft-furred mouse. The Natal multimammate rat is the natural host of the Lassa fever virus.
Chapare mammarenavirus or Chapare virus is a virus from the family Arenaviridae which causes a hemorrhagic fever in humans known as Chapare hemorrhagic fever. It was first described after an outbreak of a novel zoonotic mammarenavirus infection occurred in the village of Samuzabeti, Chapare Province, Bolivia, in January 2003. A small number of people were infected and one person died.
Powassan encephalitis, caused by the Powassan virus (POWV), a flavivirus also known as the deer tick virus, is a form of arbovirus infection that results from tick bites. It can occur as a co-infection with Lyme disease, as both are transmitted to humans by the same species of tick. Over the last decade, there has been a surge in the number of cases and an expansion of its geographic range. In the United States, cases have been documented primarily in the northeast. The disease was first isolated from the brain of a boy who died of encephalitis in Powassan, Ontario, in 1958. This disease is classified as a zoonosis, originating in animals, often found in rodents and ticks, with subsequent transmission to humans. The virus shares antigenic similarities with the Far Eastern tick-borne encephalitis viruses.
A robovirus is a zoonotic virus that is transmitted by a rodent vector.
Lujo is a bisegmented RNA virus—a member of the family Arenaviridae—and a known cause of viral hemorrhagic fever (VHF) in humans. Its name was suggested by the Special Pathogens Unit of the National Institute for Communicable Diseases of the National Health Laboratory Service (NICD-NHLS) by using the first two letters of the names of the cities involved in the 2008 outbreak of the disease, Lusaka (Zambia) and Johannesburg. It is the second pathogenic Arenavirus to be described from the African continent—the first being Lassa virus—and since 2012 has been classed as a "Select Agent" under U.S. law.
Dabie bandavirus, also called SFTS virus, is a tick-borne virus in the genus Bandavirus in the family Phenuiviridae, order Bunyavirales. The clinical condition it caused is known as severe fever with thrombocytopenia syndrome (SFTS). SFTS is an emerging infectious disease that was first described in northeast and central China 2009 and now has also been discovered in Japan, South Korea, Vietnam and Taiwan in 2015. SFTS has a fatality rate of 12% and as high as over 30% in some areas. The major clinical symptoms of SFTS are fever, vomiting, diarrhea, multiple organ failure, thrombocytopenia, leukopenia and elevated liver enzyme levels. Another outbreak occurred in East China in the early half of 2020.
Caño Delgadito orthohantavirus (CADV) is a hantavirus present in Venezuela. Its natural reservoir is Alston's cotton rat. Transmission among cotton rats appears to be horizontal. While human disease caused by CADV has not yet been identified, it has been isolated from oropharyngeal swabs and urine of infected cotton rats, indicating that it may be infectious to humans in the same manner as other hantaviruses, via inhalation of aerosolized droplets of saliva, respiratory secretions, or urine. CADV was discovered in the 1990s from rodent species in the Llanos in Venezuela.
Negative-strand RNA viruses are a group of related viruses that have negative-sense, single-stranded genomes made of ribonucleic acid (RNA). They have genomes that act as complementary strands from which messenger RNA (mRNA) is synthesized by the viral enzyme RNA-dependent RNA polymerase (RdRp). During replication of the viral genome, RdRp synthesizes a positive-sense antigenome that it uses as a template to create genomic negative-sense RNA. Negative-strand RNA viruses also share a number of other characteristics: most contain a viral envelope that surrounds the capsid, which encases the viral genome, −ssRNA virus genomes are usually linear, and it is common for their genome to be segmented.
Praomyini is a tribe of muroid rodents in the subfamily Murinae. Species in this tribe are found mostly throughout Sub-Saharan Africa, but one species is found in North Africa, and another is found in the Arabian Peninsula.
Mopeia mammarenavirus (MOPV) is a species of virus in the genus Mammarenavirus. It was initially isolated from the Mastomys natalensis mouse in the East African country of Mozambique in 1977. It is of the "Old World" Arenavirus lineage and is closely related to Lassa mammarenavirus, sharing 75% of its amino acid sequence.
