Changing the face of fever of unknown origin in Egypt: a single hospital study

Dear Editor,

Infections remain the most frequent cause of fever ofunknown origin (FUO) in developing countries. Some casesof fever remain a mystery and patients are discharged with-out knowing the cause. Prehospital healthcare facilities varybetween countries, and even within the same country. FUOwas first described in 1961 by Petersdorf and Beeson whenthey established the three criteria that define FUO: a minimummeasured temperature of 38.3◦C, febrile states occurring onseveral occasions over a period of at least three weeks, and aminimum of one week of investigations being required.¹ Themodern definition of FUO is based on modifications of thesecriteria 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 accordingto the latest definition and compare the causes with those ofa previous study conducted at the same hospital in 1974.⁴ Weretrospectively reviewed 374 adult patients with FUO admittedto the Abbassia Fever Hospital under the definition outlinedby Durack and Street (1991).⁵ Data were obtained from admission files. The patient population comprised 217 (58%) malepatients, with a mean age of 40.2 ± 14.5 years. Further, 240patients (64.2%) lived in urban areas, while 134 (35.8%) livedin 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 interremittent 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 mis- cellaneous group, and 29 (7.8%) were discharged without a final diagnosis (Table 1)

Table 1 -
Final diagnosis in the studied population.

• ^a
  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).
• ^b
  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.

REFERENCES

• ¹
  Petersdorf R, Beeson P. Fever of unexplained origin: report on 100 cases. Medicine. 1961;40:1-30.
• ²
  Mourad O, Palda V, Detsky A. A comprehensive evidence-based approach to fever of unknown origin. Arch Intern Med. 2003;163:545.
• ³
  Bleeker-Rover CP, Vos FJ, de Kleijn EM, et al. A prospective multicenter study on fever of unknown origin: the yield of a structured diagnostic protocol. Medicine (Baltimore). 2007;86:26-38.
• ⁴
  Farid Z, Hassan AL. Fever of undetermined origin in Cairo. N Engl J Med. 1974;290:807.
• ⁵
  Durack D, Street A. Fever of unknown origin - reexamined and redefined. CurrClin Top Inf Dis. 1991;11:35-51.

• 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.

Publication Dates

• Publication in this collection
  May-Jun 2015

History

• Received
  14 Feb 2015
• Accepted
  25 Feb 2015