Outbreaks
1959 - 1964
This was both the first and most severe outbreak of Bolivian hemorrhagic fever. The outbreak had two major geographic origins. From 1959 to 1962, the spread was contained within the Iténez province, just west of the City of San Joaquín in Mamoré. In 1963, however, the focus of the outbreak shifted to San Joaquín as the number of cases peaked. [14] While the number of estimated cases vary, around 984 to 1028 cases were reported with between 245 and 256 fatalities during the five year outbreak. [2] [14] The suspected cause of this outbreak was the proliferation of the large vesper mouse following a decrease in the feline population. [3]
1965
In 1965, there were an additional 24 cases originating in San Joaquín that closely followed rodent concentration patterns. [14]
1966 - 1968
During this period of time there was little Machupo activity. There were two suspected and 13 proven cases of BHF with zero fatalities. The cases were all from San Joaquín and its smaller surrounding villages. It is of note that this was the largest outbreak without fatalities. [14]
1969 and 1970
In early 1969, there were ten cases of BHF reported with six fatalities in the town of La Cayoba outside the city of Magdalena. Residents of La Cayoba fled to Magdalena in the order to avoid the outbreak. However, in March 1969, BHF was reported in Magdalena. Through the end of 1969, 20 cases were reported in Magdalena followed by an additional 12 in 1970. [14]
1971
The 1971 outbreak of BHF occurred in Cochabamba, Bolivia, a city in central Bolivia. While far from the habitat of the lineage of large vesper mice known to carry Machupo virus, patient zero had recently traveled to that area. Once back in Cochabamba, the virus was spread to two family members and three medical personnel of the hospital in which she was admitted. Of the six total people infected, there was five fatalities including patient zero. This outbreak was of serious significance due to the primary transmission of direct human to human contact and the prevalence of the disease outside of northeast Bolivia. [11]
1976- 1993
During this time period there were no reported cases of Bolivian hemorrhagic fever. This is believed to have been caused by rodent reduction programs or potentially underreporting. [2]
1994
The 1994 outbreak began in July with a familial outbreak in Magdalena. Seven family members of an extended family became ill over the course of a month. Patient zero was the only survivor. Additionally, a lab technician handling the blood of an infected family member became infected but survived after a test tube broke. In August, there was an additional unrelated case in Magdalena that resulted in one fatality. Finally in September, an agricultural worker in Poponas was infected but survived. [15]
2007-2008 Outbreak
In early 2007, there were at least 20 suspected cases of Bolivian hemorrhagic fever reported in Beni, including three from Magdalena in which two of the patients did not survive. Additionally, one other suspected case ended in a fatality. [6]
In February 2008, over 200 suspected cases of BHF were reported with 12 fatalities. These cases included incidents in Huacaraje, Iténez and San Ramon, Mamoré. [6]
Outbreak Confusion with Chapare Virus
Chapare Virus (CHAPV) was first described during an outbreak near Cochabamba during December 2003 and January 2004. [9] Originally thought to be an etiological agent of BHF along with Machupo virus, it is now considered to be significantly genetically distinct and the etiological agent of Chapare hemorrhagic fever (CHHF). [7] [9] [16] However, this has lead to confusion of what is and is not a BHF outbreak. Some sources may show BHF cases beyond 2000 that are now understood to be CHHF rather than BHF including the 2003-2004, 2019, and 2020 outbreaks. [2] [7]
Weaponization
Due to its high lethality, Bolivian hemorrhagic fever was one of three hemorrhagic fevers and one of more than a dozen agents that the United States researched as potential biological weapons before the nation suspended its biological weapons program in 1969. During this program, Albert Nickel, a 53-year old animal caretaker at Fort Detrick, died in 1964 from BHF after being bitten by an infected mouse. Nickel Place, on Fort Detrick, is named in his honor. BHF was also being researched by the Soviet Union, under the Biopreparat bureau. [17]
