Lassa fever epidemiology and demographics: Difference between revisions
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*Guinea 4–55% | *Guinea 4–55% | ||
*Nigeria approx. 21% | *Nigeria approx. 21% | ||
[[File:Outbreak Distribution Map Lassa Fever CDC.png|thumb|center|400 px|Outbreak Distribution Map Lassa Fever CDC.png<SMALL><SMALL>''[http://www.cdc.gov/vhf/lassa/outbreaks/index.html]''<ref name="CDC">{{Cite web | title = Center for Disease Control and Prevention (CDC) | url = http://www.cdc.gov}}</ref></SMALL></SMALL>]] | [[File:Outbreak Distribution Map Lassa Fever CDC.png|thumb|center|400 px|Outbreak Distribution Map Lassa Fever CDC.png<SMALL><SMALL>''[http://www.cdc.gov/vhf/lassa/outbreaks/index.html]''<ref name="CDC">{{Cite web | title = Center for Disease Control and Prevention (CDC) | url = http://www.cdc.gov}}</ref></SMALL></SMALL>]] | ||
* | * A serological survey among patients admitted with a history of fever and missionaries that had experienced a febrile illness showed that LASV was also present in Ivory Coast, Mali, and Central African Republic<ref name="pmid1085213">{{cite journal| author=Frame JD| title=Surveillance of Lassa fever in missionaries stationed in West Africa. | journal=Bull World Health Organ | year= 1975 | volume= 52 | issue= 4-6 | pages= 593-8 | pmid=1085213 | doi= | pmc=PMC2366625 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1085213 }} </ref>. | ||
* The notion that LASV was endemic in larger areas of West Africa was further supported by the results of investigation of an imported case of Lassa fever in Germany in 2000. | * The notion that LASV was endemic in larger areas of West Africa was further supported by the results of investigation of an imported case of Lassa fever in Germany in 2000. | ||
* During the incubation period, the index patient traveled through several countries, namely Ghana, Ivory Coast, and Burkina Faso, that were not considered to be endemic at that time | * During the incubation period, the index patient traveled through several countries, namely Ghana, Ivory Coast, and Burkina Faso, that were not considered to be endemic at that time<ref name="pmid10998376">{{cite journal| author=Günther S, Emmerich P, Laue T, Kühle O, Asper M, Jung A et al.| title=Imported lassa fever in Germany: molecular characterization of a new lassa virus strain. | journal=Emerg Infect Dis | year= 2000 | volume= 6 | issue= 5 | pages= 466-76 | pmid=10998376 | doi=10.3201/eid0605.000504 | pmc=PMC2627947 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10998376 }} </ref>. Later, cases of Lassa fever have been reported from Burkina Faso, Ivory Coast, Ghana, Senegal, Gambia, and Mali<ref name="pmid17848068">{{cite journal| author=Gonzalez JP, Emonet S, de Lamballerie X, Charrel R| title=Arenaviruses. | journal=Curr Top Microbiol Immunol | year= 2007 | volume= 315 | issue= | pages= 253-88 | pmid=17848068 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17848068 }} </ref><ref name="pmid20587185">{{cite journal| author=Safronetz D, Lopez JE, Sogoba N, Traore' SF, Raffel SJ, Fischer ER et al.| title=Detection of Lassa virus, Mali. | journal=Emerg Infect Dis | year= 2010 | volume= 16 | issue= 7 | pages= 1123-6 | pmid=20587185 | doi=10.3201/eid1607.100146 | pmc=PMC3321918 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20587185 }} </ref>. | ||
* According to estimations, LASV is responsible for 100,000-300,000 infections and approximately 5,000 deaths annually [ | * According to estimations, LASV is responsible for 100,000-300,000 infections and approximately 5,000 deaths annually. Unfortunately, such estimates are crude, because [[disease surveillance|surveillance]] for cases of the disease is not uniformly performed. In some areas of Sierra Leone and Liberia, it is known that 10%-16% of people admitted to hospitals have Lassa fever, which indicates the serious impact of the disease on the population of this region. | ||
* The high degree of seroprevalence of LASV-specific antibodies in the general population residing in the endemic regions, although highly variable depending on the geographical location (from 1.8% to 55%) [<ref name="pmid3805771">{{cite journal| author=McCormick JB, Webb PA, Krebs JW, Johnson KM, Smith ES| title=A prospective study of the epidemiology and ecology of Lassa fever. | journal=J Infect Dis | year= 1987 | volume= 155 | issue= 3 | pages= 437-44 | pmid=3805771 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3805771 }} </ref> indicates that most infections are mild or possibly even asymptomatic and do not result in hospitalization. This is also supported by the findings indicating a high incidence of LASV-specific seroconversion, from 5% to 20% of the nonimmune population per year<ref name="pmid3805771">{{cite journal| author=McCormick JB, Webb PA, Krebs JW, Johnson KM, Smith ES| title=A prospective study of the epidemiology and ecology of Lassa fever. | journal=J Infect Dis | year= 1987 | volume= 155 | issue= 3 | pages= 437-44 | pmid=3805771 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3805771 }} </ref>. Nosocomial outbreaks are associated with higher mortality rates ranging from 36% to 65%<ref name="pmid4745236">{{cite journal| author=Monath TP, Mertens PE, Patton R, Moser CR, Baum JJ, Pinneo L et al.| title=A hospital epidemic of Lassa fever in Zorzor, Liberia, March-April 1972. | journal=Am J Trop Med Hyg | year= 1973 | volume= 22 | issue= 6 | pages= 773-9 | pmid=4745236 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=4745236 }} </ref>. | |||
==References== | ==References== | ||
Revision as of 02:42, 6 June 2015
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [2]
Synonyms and keywords: Lassa hemorrhagic fever; LHF
Overview
Epidemiology and Demographics
Prevalence
The dissemination of the infection can be assessed by prevalence of antibodies to the virus in populations of:
- Sierra Leone 8–52%
- Guinea 4–55%
- Nigeria approx. 21%
- A serological survey among patients admitted with a history of fever and missionaries that had experienced a febrile illness showed that LASV was also present in Ivory Coast, Mali, and Central African Republic[2].
- The notion that LASV was endemic in larger areas of West Africa was further supported by the results of investigation of an imported case of Lassa fever in Germany in 2000.
- During the incubation period, the index patient traveled through several countries, namely Ghana, Ivory Coast, and Burkina Faso, that were not considered to be endemic at that time[3]. Later, cases of Lassa fever have been reported from Burkina Faso, Ivory Coast, Ghana, Senegal, Gambia, and Mali[4][5].
- According to estimations, LASV is responsible for 100,000-300,000 infections and approximately 5,000 deaths annually. Unfortunately, such estimates are crude, because surveillance for cases of the disease is not uniformly performed. In some areas of Sierra Leone and Liberia, it is known that 10%-16% of people admitted to hospitals have Lassa fever, which indicates the serious impact of the disease on the population of this region.
- The high degree of seroprevalence of LASV-specific antibodies in the general population residing in the endemic regions, although highly variable depending on the geographical location (from 1.8% to 55%) [[6] indicates that most infections are mild or possibly even asymptomatic and do not result in hospitalization. This is also supported by the findings indicating a high incidence of LASV-specific seroconversion, from 5% to 20% of the nonimmune population per year[6]. Nosocomial outbreaks are associated with higher mortality rates ranging from 36% to 65%[7].
References
- ↑ "Center for Disease Control and Prevention (CDC)".
- ↑ Frame JD (1975). "Surveillance of Lassa fever in missionaries stationed in West Africa". Bull World Health Organ. 52 (4–6): 593–8. PMC 2366625. PMID 1085213.
- ↑ Günther S, Emmerich P, Laue T, Kühle O, Asper M, Jung A; et al. (2000). "Imported lassa fever in Germany: molecular characterization of a new lassa virus strain". Emerg Infect Dis. 6 (5): 466–76. doi:10.3201/eid0605.000504. PMC 2627947. PMID 10998376.
- ↑ Gonzalez JP, Emonet S, de Lamballerie X, Charrel R (2007). "Arenaviruses". Curr Top Microbiol Immunol. 315: 253–88. PMID 17848068.
- ↑ Safronetz D, Lopez JE, Sogoba N, Traore' SF, Raffel SJ, Fischer ER; et al. (2010). "Detection of Lassa virus, Mali". Emerg Infect Dis. 16 (7): 1123–6. doi:10.3201/eid1607.100146. PMC 3321918. PMID 20587185.
- ↑ 6.0 6.1 McCormick JB, Webb PA, Krebs JW, Johnson KM, Smith ES (1987). "A prospective study of the epidemiology and ecology of Lassa fever". J Infect Dis. 155 (3): 437–44. PMID 3805771.
- ↑ Monath TP, Mertens PE, Patton R, Moser CR, Baum JJ, Pinneo L; et al. (1973). "A hospital epidemic of Lassa fever in Zorzor, Liberia, March-April 1972". Am J Trop Med Hyg. 22 (6): 773–9. PMID 4745236.