Editing Lassa fever (section)

==Diagnosis==
[[Image:454277-Q-GYI14-255(1).jpg|thumb|Liberian laboratory technicians in [[personal protective equipment]] preparing to test Lassa fever samples.]]
A range of laboratory investigations are performed, where possible, to diagnose the disease and assess its course and complications. The confidence of a diagnosis can be compromised if laboratory tests are not available. One comprising factor is the number of febrile illnesses present in Africa, such as [[malaria]] or [[typhoid fever]] that could potentially exhibit similar symptoms, particularly for non-specific manifestations of Lassa fever.<ref name=":1" /> In cases with [[abdominal pain]], in countries where Lassa is common, Lassa fever is often misdiagnosed as [[appendicitis]] and [[Intussusception (medical disorder)|intussusception]] which delays treatment with the antiviral [[ribavirin]].<ref>{{cite journal|last1=Dongo|first1=A. E.|last2=Kesieme|first2=E. B.|last3=Iyamu|first3=C. E.|last4=Okokhere|first4=P. O.|last5=Akhuemokhan|first5=O. C.|last6=Akpede|first6=G. O.|year=2013|title=Lassa fever presenting as acute abdomen: a case series|journal=Virology Journal|volume=10|pages=124|doi=10.1186/1743-422X-10-123|pmid=23597024|pmc=3639802 |doi-access=free }}</ref> In West Africa, where Lassa is most common, it is difficult to diagnose due to the absence of proper equipment to perform testing.<ref name="pmid23029594|noedit">{{Cite journal | last1 = Asogun | first1 = D. A. | last2 = Adomeh | first2 = D. I. | last3 = Ehimuan | first3 = J. | last4 = Odia | first4 = I. | last5 = Hass | first5 = M. | last6 = Gabriel | first6 = M. | last7 = Olschläger | first7 = S. | last8 = Becker-Ziaja | first8 = B. | last9 = Folarin | first9 = O. | last10 = Phelan | first10 = E. | last11 = Ehiane | first11 = P. E. | last12 = Ifeh | first12 = V. E. | last13 = Uyigue | first13 = E. A. | last14 = Oladapo | first14 = Y. T. | last15 = Muoebonam | first15 = E. B. | last16 = Osunde | first16 = O. | last17 = Dongo | first17 = A. | last18 = Okokhere | first18 = P. O. | last19 = Okogbenin | first19 = S. A. | last20 = Momoh | first20 = M. | last21 = Alikah | first21 = S. O. | last22 = Akhuemokhan | first22 = O. C. | last23 = Imomeh | first23 = P. | last24 = Odike | first24 = M. A. | last25 = Gire | first25 = S. | last26 = Andersen | first26 = K. | last27 = Sabeti | first27 = P. C. | last28 = Happi | first28 = C. T. | last29 = Akpede | first29 = G. O. | last30 = Günther | first30 = S. | editor1-last = Bausch | editor1-first = Daniel G | title = Molecular Diagnostics for Lassa Fever at Irrua Specialist Teaching Hospital, Nigeria: Lessons Learnt from Two Years of Laboratory Operation | doi = 10.1371/journal.pntd.0001839 | journal = PLOS Neglected Tropical Diseases | volume = 6 | issue = 9 | pages = e1839 | year = 2012 | pmid = 23029594 | pmc =3459880 | doi-access = free }}</ref>

The United States FDA has yet to approve a widely validated laboratory test for Lassa, but there are tests that have been able to provide definitive proof of the presence of the LASV virus.<ref name=":1" /> These tests include cell cultures, PCR, ELISA antigen assays, plaque neutralization assays, and immunofluorescence essays. However, immunofluorescence essays provide less definitive proof of Lassa infection.<ref name=":1" /> An [[ELISA]] test for antigen and [[Immunoglobulin M]] antibodies give 88% sensitivity and 90% specificity for the presence of the infection. Other laboratory findings in Lassa fever include [[lymphocytopenia]] (low lymphocyte white blood cell count), [[thrombocytopenia]] (low platelets), and elevated [[aspartate transaminase]] <!-- (AST) --> levels in the blood. Lassa fever virus can also be found in [[cerebrospinal fluid]].<ref>{{Cite journal | last1 = Günther | first1 = S. | last2 = Weisner | first2 = B. | last3 = Roth | first3 = A. | last4 = Grewing | first4 = T. | last5 = Asper | first5 = M. | last6 = Drosten | first6 = C. |author-link6=Christian Drosten | last7 = Emmerich | first7 = P. | last8 = Petersen | first8 = J. | last9 = Wilczek | first9 = M. | doi = 10.1086/322033 | last10 = Schmitz | first10 = H. | title = Lassa Fever Encephalopathy: Lassa Virus in Cerebrospinal Fluid but Not in Serum | journal = The Journal of Infectious Diseases | volume = 184 | issue = 3 | pages = 345–349 | year = 2001 | pmid = 11443561 | doi-access = free }}</ref>