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Vol. 19. Issue 3.
Pages 334-335 (May - June 2015)
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Vol. 19. Issue 3.
Pages 334-335 (May - June 2015)
Letter to the Editor
Open Access
Changing the face of fever of unknown origin in Egypt: a single hospital study
Mohammed Fawzy Montasser, Nadia Abdelaaty Abdelkader, Iman Fawzy Montasser
Corresponding author

Corresponding author at: Tropical Medicine Department, Ain Shams University Hospital, El-Abbassia Square, Cairo, Egypt.
Department of Tropical Medicine, Faculty of Medicine, Ain Shams University, Cairo, Egypt
Ahmed Mahmoud El Khouly
Al Abbassyia Fevers Hospital, Cairo, Egypt
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Tables (1)
Table 1. Final diagnosis in the studied population.
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Dear Editor,

Infections remain the most frequent cause of fever of unknown origin (FUO) in developing countries. Some cases of fever remain a mystery and patients are discharged without knowing the cause. Prehospital healthcare facilities vary between countries, and even within the same country. FUO was first described in 1961 by Petersdorf and Beeson when they established the three criteria that define FUO: a minimum measured temperature of 38.3°C, febrile states occurring on several occasions over a period of at least three weeks, and a minimum of one week of investigations being required.1 The modern definition of FUO is based on modifications of these criteria taking into account four specific patient subtypes: classic, nosocomial, immunedeficient (neutropenic), and HIV-associated FUO.2,3

We outlined changes in causes of classic FUO according to the latest definition and compare the causes with those of a previous study conducted at the same hospital in 1974.4 We retrospectively reviewed 374 adult patients with FUO admitted to the Abbassia Fever Hospital under the definition outlined by Durack and Street (1991).5 Data were obtained from admission files. The patient population comprised 217 (58%) male patients, with a mean age of 40.2±14.5 years. Further, 240 patients (64.2%) lived in urban areas, while 134 (35.8%) lived in rural areas.

A continuous pattern of fever was found in 211 patients (58.3%), while 58 patients (16%) presented with a remittent pattern, and 87 patients (23.2%) showed intermittent fever symptoms. Six patients (1.6%) had relapsing fever.

Blood cultures grew Gram-negative organisms in only nine cases (2.4%) and Gram-positive in eight cases (2.1%). Also, in urine cultures Gram-negative organisms were dominant including E. coli, Klebsiella and Enterobacter while Gram-positive cocci were only S. aureus.

With regard to the final diagnosis, 248 patients (66.3%) were diagnosed with an infection etiology for FUO. Of these patients, 46 had cytomegalovirus infection (CMV). Among the non-infection patients, 49 (13.1%) were categorized in the miscellaneous group, and 29 (7.8%) were discharged without a final diagnosis (Table 1)

Table 1.

Final diagnosis in the studied population.

Final diagnosis  Frequency  Percent 
Infection  248  66.3 
CMV  46  12.3 
UTI  39  10.4 
Bronchitis  35  9.4 
Pneumonia  26  7.0 
Typhoid fever  23  6.1 
Brucellosis  22  5.9 
Septicemia  13  3.5 
Tuberculosis  11  2.9 
Infective endocarditis  2.1 
Chronic hepatitis  1.6 
Other infectionsa  19  5.1 
Collagen diseases  27  7.2 
Rheumatoid arthritis  13  3.5 
SLE  1.9 
Adult Still's disease  1.6 
Rheumatic fever  0.3 
Malignancy  27  7.2 
Blood malignancy  20  3.5 
Solid malignancy  1.9 
Miscellaneousb  43  11.5 
IBD  10  2.6 
Drug fever  2.4 
Behcet's disease  2.1 
FMF  1.6 
Undiagnosed  29  7.8 
Total  374  100.0 

Other infections: EBV (4 patients), enterocolitis (3 patients), pelvic abscess (3 patients), cholecystitis (2 patients), liver abscess (2 patients), pyelonephritis (2 patients), Appendicular abscess (1 patient), encephalitis (1 patient) and gluteal abscess (1 patient).


Miscellaneous: thyrotoxicosis (5 patients), liver cell failure (4 patient) and portal vein thrombosis (1 patient).

Comparing the findings of the present study with a similar study conducted in 1974 that examined 129 patients with FUO in the same hospital,4 we found that infections still represent the main cause of FUO in Egypt (66.3% vs. 60% in 1974); however, the percentage of undiagnosed cases has dropped from 12% to 7.8%. Salmonella infection was diagnosed in 23 of 248 cases of infection, while brucellosis accounted for 22 cases.

Infections remain the predominant cause of FUO in Egypt; however, the causative agents have changed over the last 40 years. The proportion of undiagnosed cases of FUO seems to be lower than what it was in the past due to advances in diagnostic technologies. Finally, clinicians must be aware that the etiology of FUO varies across demographics, geography, and time. Accordingly, reporting local cases is important in informing clinicians about the epidemiologic pattern.


Prof Mohamed Fawzy Montasser: Chosen the research idea and revised the results Ass. Prof Nadia Abdelaaty: follow up data collection, revise the results and wrote the manuscript. Dr Iman Montasser: data analysis, wrote and submitted the manuscript, Dr Ahmed El Khouly: Data collection, statistical analysis.

Ethics statement

This study was carried out after approval of Research and Ethics Committee of Ain Shams University, Cairo, Egypt in accordance with local research governance requirements. All human studies have been approved by the appropriate ethics committee and have therefore been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and all subsequent revisions.

Sources of funding

This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

Conflicts of interest

There are no financial or other relations that could lead to a conflict of interest.

R. Petersdorf, P. Beeson.
Fever of unexplained origin: report on 100 cases.
Medicine, 40 (1961), pp. 1-30
O. Mourad, V. Palda, A. Detsky.
A comprehensive evidence-based approach to fever of unknown origin.
Arch Intern Med, 163 (2003), pp. 545
C.P. Bleeker-Rover, F.J. Vos, E.M. de Kleijn, et al.
A prospective multicenter study on fever of unknown origin: the yield of a structured diagnostic protocol.
Medicine (Baltimore), 86 (2007), pp. 26-38
Z. Farid, A.L. Hassan.
Fever of undetermined origin in Cairo.
N Engl J Med, 290 (1974), pp. 807
D. Durack, A. Street.
Fever of unknown origin – reexamined and redefined.
CurrClin Top Inf Dis, 11 (1991), pp. 35-51
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