Management of children with prolonged fever of unknown origin and difficulties in the management of fever of unknown origin in children in developing countries

Impact of a package of point-of-care diagnostic tests, a clinical diagnostic algorithm and adherence training on antibiotic prescriptions for the management of non-severe acute febrile illness in primary health facilities during the COVID-19 pandemic in Burkina Faso

OBJECTIVE

To assess the impact of an intervention package on the prescription of antibiotic and subsequently the rate of clinical recovery for non-severe acute febrile illnesses at primary health centers.

METHODS

Patients over 6 months of age presenting to primary health care centres with fever or history of fever within the past 7 days were randomized to receive either the intervention package constituted of point-of-care tests including COVID-19 antigen tests, a diagnostic algorithm and training and communication packages, or the standard practice. The primary outcomes were antibiotic prescriptions at Day 0 (D0) and the clinical recovery at Day 7 (D7). Secondary outcomes were non-adherence of participants and parents/caregivers to prescriptions, health workers' non-adherence to the algorithm, and the safety of the intervention.

RESULTS

A total of 1098 patients were enrolled. 551 (50.2%) were randomized to receive the intervention versus 547 (49.8%) received standard care. 1054 (96.0%) completed follow-up and all of them recovered at D7 in both arms. The proportion of patients with antibiotic prescriptions at D0 were 33.2% (183/551) in the intervention arm versus 58.1% (318/547) under standard care, risk difference (RD) -24.9 (95% CI -30.6 to -19.2, p < 0.001), corresponding to one more antibiotic saved every four (95% CI: 3 to 5) consultations. This reduction was also statistically significant in children from 6 to 59 months (RD -34.5; 95% CI -41.7 to -27.3; p < 0.001), patients over 18 years (RD -35.9; 95%CI -58.5 to -13.4; p = 0.002), patients with negative malaria test (RD -46.9; 95% CI -53.9 to -39.8; p < 0.001), those with a respiratory diagnosis (RD -48.9; 95% CI -56.9 to -41.0, p < 0.001) and those not vaccinated against COVID-19 (-24.8% 95%CI -30.7 to -18.9, p-value: <0.001). A significant reduction in non-adherence to prescription by patients was reported (RD -7.1; 95% CI -10.9 to -3.3; p < 0.001).

CONCLUSION

The intervention was associated with significant reductions of antibiotic prescriptions and non-adherence, chiefly among patients with non-malaria fever, those with respiratory symptoms and children below 5 years of age. The addition of COVID-19 testing did not have a major impact on antibiotic use at primary health centers.

TRIAL REGISTRATION

Clinitrial.gov; NCT04081051 registered on 06/09/2019.

Update on Fever of Unknown Origin in Children: Focus on Etiologies and Clinical Approach

Fever of unknown origin (FUO) can be caused by four etiological categories of diseases. The most common cause of FUO in children is represented by infections, followed by inflammatory conditions and neoplastic causes; a decreasing quote remains still without diagnosis. Despite the fact that several diagnostic and therapeutic approaches have been proposed since the first definition of FUO, none of them has been fully validated in pediatric populations. A focused review of the patient's history and a thorough physical examination may offer helpful hints in suggesting a likely diagnosis. The diagnostic algorithm should proceed sequentially, and invasive testing should be performed only in select cases, possibly targeted by a diagnostic suspect. Pioneering serum biomarkers have been developed and validated; however, they are still far from becoming part of routine clinical practice. Novel noninvasive imaging techniques have shown promising diagnostic accuracy; however, their positioning in the diagnostic algorithm of pediatric FUO is still not clear. This narrative review aims to provide a synopsis of the existent literature on FUO in children, with its major causes and possible diagnostic workup, to help the clinician tackle the complex spectrum of pediatric FUO in everyday clinical practice.

The effect of malaria rapid diagnostic tests results on antimicrobial prescription practices of health care workers in Burkina Faso

BACKGROUND

Malaria rapid diagnostic tests (RDT) are widely used in endemic areas in order to comply with the recommendation that malaria treatment should only be given after the clinical diagnosis has been confirmed by RDT or microscopy. However, the overestimation of malaria infection with the use of PfHRP2 based RDT, makes the management of febrile illnesses more challenging. This study aimed to assess the effect of the use of malaria RDT on antimicrobial prescription practices.

METHODS

A prospective study was conducted among febrile children under-5 years of age attending four health facilities and the referral hospital in the Nanoro Health District (Burkina Faso). To assess the effect of malaria RDT testing on the prescriptions of antimicrobials in febrile children, the initial diagnosis and antimicrobial prescriptions following a malaria RDT testing were recorded. The necessity of these prescriptions was subsequently checked by assessing the actual cause of fever by expert malaria microscopy and a microbiology analysis of blood, urine, stool and nasopharynx swabs that were collected from febrile cases to determine the actual cause of the fever episode.

RESULTS

Malaria was diagnosed by nurses, who are the primary health care providers, with a malaria RDT in 72.7% (798/1098) of febrile children, but only 53.7% (589/1097) cases could be confirmed by expert microscopy. Health care workers were likely to prescribe antimalarials to malaria positive RDT compared to malaria negative RDT (RR = 7.74, p = 0.00001). Malaria negative RDT result had a significant influence on the antibiotic prescriptions (RR = 3.57, p = 0.0001). The risk of prescribing antimicrobials was higher in health facility level compared to referral hospital. By cross-checking of laboratory findings to antimicrobial prescriptions, an important part of children with positive bacterial infection have received antibiotic prescriptions although the majority without any infection have also received antibiotics.

CONCLUSION

Despite the good attitude of health care workers to adhere to diagnostic test results, antimalarials and antibiotics remain inappropriate prescribed to febrile children. The low specificity of malaria RDT used could be an important cause of these practices.

Prevalence of Lassa Virus Disease (LVD) in Nigerian children with fever or fever and convulsions in an endemic area

Background

Convulsions with fever in children are a common neurologic emergency in the tropics, and determining the contribution of endemic viral infections can be challenging. In particular, there is a dearth of data on the prevalence and clinical differentiation of Lassa virus disease (LVD) in febrile children in endemic areas of Nigeria, which has multiple lineages of the virus. The aim of this study was to determine the prevalence and presentation of LVD in febrile children with and without convulsions.

Methodology/Principal findings

This was a prospective study of consecutive febrile children aged ≥1 month– 15 years admitted to the Children’s Emergency Room of Irrua Specialist Teaching Hospital over a period of 1 year. Febrile children with convulsions (Cases) were compared with those without convulsions (Controls). LVD was defined by the presence of a positive Lassa virus RT-PCR test. Rates were compared between groups using χ2 or Fisher’s exact tests and p <0.05 taken as significant. 373 (40.9%) of 913 admissions had fever. Of these, 108/373 (29%) presented with convulsions. The overall prevalence of LVD was 13/373 (3.5%; 95% CI = 1.9%, 5.7%) in febrile admissions, 3/108 (2.8%) in Cases and 10/265 (3.8%) in Controls [(Odds Ratio (95% Confidence Interval) (OR (95% CI)) of LVD in Cases versus Controls = 0.73 (0.2, 2.7)]. Only vomiting (OR (95% CI) = 0.09 (0.01, 0.70)) and bleeding (OR (95% CI) = 39.56 (8.52, 183.7)) were significantly associated with an increased prevalence of LVD.

Conclusions/Significance

LVD is an important cause of fever, including undifferentiated fever in children in endemic areas, but it is not significantly associated with convulsions associated with fever. Its prevalence, and lack of clinical differentiation on presentation, underscores the importance of a high index of suspicion in diagnosis. Screening of febrile children with undifferentiated fever in endemic areas for LVD could be an important medical and public health control measure.

There has, perhaps, been undue focus on malaria as a cause of childhood fever and convulsions, often with delayed/missed diagnosis of other serious prevalent infections, and correspondingly very little published data on the contribution of Lassa virus disease (LVD) in endemic areas. There is also very little published data on the contribution of LVD to childhood morbidity and mortality in Nigeria, a large LVD-endemic country that has in circulation 3 of the 4 currently known lineages of the Lassa virus. This study was carried out to address these gaps. The results should also be of relevance in the formulation of policies for the treatment and control of viral haemorrhagic fevers. The prevalence of LVD was 5.4% among children with clinically undifferentiated fever (n = 243); 3.9% among those with convulsions associated with fever (n = 77) and 6.0% among those with fever but no convulsions (n = 166). The results underscore the importance of LVD as a cause of acute undifferentiated fever. The results also underscore the need of diagnostic testing for LVD in children with acute undifferentiated fever in endemic areas in order to facilitate control, including the prevention of nosocomial transmission.

Etiology and clinical characteristics of fever of unknown origin in children: a 15-year experience in a single center

Purpose

Fever is one of the most common symptoms in children. In previous studies, infectious disease was the most common cause of pediatric fever of unknown origin (FUO). The aim of this study is to investigate the etiology, clinical characteristics and prognosis of pediatric FUO in 21 century with more diagnostics available and to analyze the factors for certain disease categories.

Methods

Among the children under 18 years old who were hospitalized at Samsung Medical Center from January 2000 to December 2014, the patients who met the criteria including fever of ≥38.0℃ for longer than ≥14 days and failure to reach a diagnosis after one week of investigations were included.

Results

Total 100 patients were identified. Confirmed diagnosis was achieved in 57 patients (57%). Among them, infectious diseases (n=19, 19%) were most common, followed by connective tissue diseases (n=15, 15%), necrotizing lymphadenitis (n=8, 8%), and malignancies (n=7, 7%). Children with fever duration over 28 days had a trend for higher frequency of connective tissue diseases (28.3%) except undiagnosed etiology. The symptoms such as arthritis, lymph node enlargement and only fever without other symptoms were significantly related with connective tissue diseases, necrotizing lymphadenitis and undiagnosed respectively (P<0.001). Ninety-two patients have become afebrile at discharge and 1 patient died (1%).

Conclusion

Almost half of our patients were left without diagnosis. Although it has been known that infectious disease was most common cause of pediatric FUO in the past, undiagnosed portion of FUO have now increased due to development of diagnostic techniques for infectious diseases.

Childhood brucellosis: Review of 317 cases

OBJECTIVE

To describe the main epidemiological, clinical, and laboratory features, treatment options and outcome in children with brucellosis.

METHODS

Retrospectively evaluated data were obtained from 317 pediatric patients with brucellosis that were treated at the University Clinic for Infectious Diseases and Febrile Conditions in Skopje, during the period from 1989 to 2011. The medical records and follow-up protocols were used for evaluation.

RESULTS

Childhood brucellosis composed 317 (18.7%) of 1691 patients with brucellosis. The patients were median 9 years old, ranging from 7 months to 14 years, and 201 (63.4%) were males. Family history was present in 197 (62.1%), and direct contact with animals occurred in 140 (44.2%) of the children. The dominant manifestations were fever in 248 (78.2%), joint pain in 228 (71.9%) and hepatomegaly in 216 (68.1%). Organ affection was present in 206 (65.0%) of the patients. One hundred and six (33.4%) of the patients were treated with combination composed of two, and 211 (66.6%) with three antimicrobial agents. Relapses were registered in 21 (6.6%), and therapeutic failures in 3 (0.9%) of the children.

CONCLUSIONS

In endemic regions childhood brucellosis represents a significant part of human cases. Wide spectrum of clinical manifestations, frequent affection of various organ systems and possibility of relapses show that brucellosis could be a serious disease in this age group. The presence of fever, joint pain, sweating, and affection of various systems in children from endemic regions should alert pediatricians for the possibility of brucellosis.

Clinical analysis of fever of unknown origin in children: A 10-year experience in a northern Taiwan medical center

BACKGROUND

Fever of unknown origin (FUO) was first described in 1961 as fever >38.3°C for at least 3 weeks with no apparent source after 1 week of investigations in the hospital. Infectious disease comprises the majority of cases (40-60%). There is no related research on FUO in children in Taiwan. The aim of this study is to determine the etiologies of FUO in children in Taiwan and to evaluate the relationship between the diagnosis and patient's demography and laboratory data.

METHODS

Children under 18 years old with fever >38.3°C for >2 weeks without apparent source after preliminary investigations at Taipei Veterans General Hospital during 2002-2012 were included. Fever duration, symptoms and signs, laboratory examinations, and final diagnosis were recorded. The distribution of etiologies and age, fever duration, laboratory examinations, and associated symptoms and signs were analyzed.

RESULTS

A total of 126 children were enrolled; 60 were girls and 66 were boys. The mean age was 6.7 years old. Infection accounted for 27.0% of cases, followed by undiagnosed cases (23.8%), miscellaneous etiologies (19.8%), malignancies (16.6%), and autoimmune disorders (12.7%). Epstein-Barr virus (EBV) and cytomegalovirus (CMV) were the most commonly found pathogens for infectious disease, and Kawasaki disease (KD) was the top cause of miscellaneous diagnosis.

CONCLUSIONS

Infectious disease remains the most common etiology. Careful history taking and physical examination are most crucial for making the diagnosis. Conservative treatment may be enough for most children with FUO, except for those suffering from malignancies.

Human herpes viruses are associated with classic fever of unknown origin (FUO) in Beijing patients

BACKGROUND

Few reports have examined the viral aetiology of fever of unknown origin (FUO).

OBJECTIVE

This study determined the prevalence of human herpes virus (HHV) DNA in blood of Chinese patients with classic FUO using the polymerase chain reaction (PCR) and explored the possible role of HHV.

STUDY DESIGN

Blood samples were collected from 186 patients (151 children, 35 adults) with classic FUO and 143 normal individuals in Beijing during the years 2009-2012. The HHV DNA, including Herpes simplex virus (HSV)-1/2, Varicella zoster virus (VZV), Cytomegalovirus (CMV), Epstein-Barr virus (EBV), and Human herpes virus (HHV)-6 and -7, was detected by multiplex PCR. The epidemiological and clinical features were also analysed.

RESULTS

HHV DNA was detected in 63 (33.9%) of the FUO patients, and the prevalence of EBV and HHV-6 was significantly higher than in the normal cohort. HHV co-infection was also frequent (10.2%) in the patients with FUO. The majority of patients with HHV infection present with a fever only. Our data also revealed that EBV infection was associated with hepatitis and abnormal blood indices, HHV-6 was associated with a cough, and HHV-7 was associated with hepatitis.

CONCLUSIONS

HHVs are associated with Chinese patients (especially for children) with classic FUO. Our study adds perspective to the aetiological and clinical characteristics of classic FUO in beijing patients.

Cat-scratch disease presenting as multiple hepatic lesions: case report and literature review

Although infectious diseases are the most prevalent cause of fevers of unknown origin (FUO), this diagnosis remains challenging in some pediatric patients. Imaging exams, such as computed tomography (CT) are frequently required during the diagnostic processes. The presence of multiple hypoattenuating scattered images throughout the liver associated with the history of cohabitation with cats should raise the suspicion of the diagnosis of cat-scratch disease (CSD), although the main etiologic agent of liver abscesses in childhood is Staphylococcus aureus. Differential diagnosis by clinical and epidemiological data with Bartonella henselae is often advisable. The authors report the case of a boy aged 2 years and 9 months with 16-day history of daily fever accompanied by intermittent abdominal pain. Physical examination was unremarkable. Abdominal ultrasound performed in the initial work up was unrevealing, but an abdominal CT that was performed afterwards disclosed multiple hypoattenuating hepatic images compatible with the diagnosis of micro abscesses. Initial antibiotic regimen included cefotaxime, metronidazole, and oxacillin. Due to the epidemiology of close contact with kittens, diagnosis of CSD was considered and confirmed by serologic tests. Therefore, the initial antibiotics were replaced by clarithromycin orally for 14 days followed by fever defervescence and clinical improvement. The authors call attention to this uncommon diagnosis in a child presenting with FUO and multiple hepatic images suggestive of micro abscesses.

[Human African trypanosomiasis: report of three cases]

Prolonged fever is an important cause of morbidity in pediatric practice, especially in tropical areas. It is above all a problem of etiological diagnosis given the vast number of etiologies. In sub-Saharan Africa, practitioners more often focus on bacterial infections and malaria at the expense of other infectious diseases such as human African trypanosomiasis (HAT), most often leading to overuse of antibiotics and antimalarials. A dramatic resurgence of HAT, also called sleeping sickness, has been reported during the last few decades in large areas of Central Africa. Furthermore, with the development of air transport, cases of children infected during a trip to Africa can be exported outside endemic areas, making diagnosis even more difficult. This parasitic infection causes a protracted, often initially unrecognized, illness with episodes of fever, headache, and malaise, accompanied by progressive lymphadenopathy, before the development of a progressive meningoencephalitis. These three case reports aim to remind practitioners of clinical and biological signs suggestive of HAT diagnosis in children living in endemic areas or having stayed there during the months prior to visiting the doctor. The prognosis is largely dependent on the precocity of diagnosis and therapeutic support.

Fever of unknown origin in children: a systematic review

BACKGROUND

there are no previous systematic reviews of published pediatric case series describing the etiology of fever of unknown origin (FUO). The purpose of collecting these data is to determine the etiologies for children with FUO in both developing and developed countries.

METHODS

the database Ovid Medline R (1950 to August 2009 week 4) and Ovid Embase (1980 to 2010 week 2) were used to conduct the search. Studies in any language were included if they provided the diagnosis in a series of 10 or more children with FUO. The diagnosis of each child at the time of publication of the study was recorded.

RESULTS

there were 18 studies that met the inclusion criteria, describing 1638 children. The diagnosis at the time of publication was malignancy for 93 children (6%), collagen vascular disease for 150 (9%), miscellaneous non-infectious conditions for 179 (11%), infection for 832 (51%), and no diagnosis for 384 (23%). There were 491 bacterial infections (59% of all infections) with common diagnoses being brucellosis, tuberculosis, and typhoid fever in developing countries, osteomyelitis, tuberculosis, and Bartonellosis in developed countries, and urinary tract infections in both. For children with no diagnosis after investigations, most had fever that ultimately resolved with no sequelae.

CONCLUSIONS

about half of FUOs in published case series are ultimately shown to be due to infections with collagen vascular disease and malignancy also being common diagnoses. However, there is such a wide variety of possibilities that investigations should primarily be driven by the clinical story.

Brucellosis as a cause of fever of unknown origin in children admitted to a tertiary hospital in the Aegean region of Turkey

The aim of the study was to determine the role of brucellosis in children with fever of unknown origin (FUO) in the Aegean region of Turkey. For this purpose, the records of all children referred or admitted with diagnosis of FUO to the Department of Pediatric Infectious Diseases, Ege University Medical School, between 2003 and 2008 were scanned and 92 cases were identified retrospectively. Fifty-eight of these 92 children (63%) were diagnosed with infectious diseases, brucellosis being the most frequent cause (15.2%). Although several other infectious diseases do appear as a cause of FUO, brucellosis should be particularly considered as a differential diagnosis.

Kikuchi-Fujimoto disease causing fever of unknown origin in a nine-year-old boy

We describe a case of fever of unknown origin (FUO) in a 9-y-old boy finally diagnosed with Kikuchi-Fujimoto disease (KFD) and discuss the implications for the management of FUO in children. KFD should be considered in the differential diagnosis of patients presenting with FUO to prevent misdiagnosis and inappropriate treatment.

Fever of unknown origin: a diagnostic approach to this vexing problem

Fever is a common complaint leading families to seek medical attention. Its routine management is the bread and butter of pediatric practice. When fever is seen as prolonged beyond the expected time course (eg, 10 days for a presumed viral respiratory tract infection or 3 weeks for mononucleosis), concern for fever of unknown origin (FUO) may ensue. This diagnosis is among the most challenging for health care providers to approach and often involves referral to subspecialists. Generally, the pace of the evaluation should be guided by the severity of the disease, rather than the anxiety of the family or of the health care providers. It is useful to recognize that uncommon manifestations of common diseases are more likely than are rare diseases. Furthermore, clues to the diagnosis are frequently present in the history and physical examination but are not elicited or unappreciated (perhaps due to time constraints). Therefore, thoroughness and repetition are vitally important. Although the differential diagnosis of FUO is vast, a thoughtful, focused approach based on information gleaned from a thorough history and physical examination (together with any laboratory or other study results) is preferable to a "shotgun" or "running the list" one. Finally, FUO in special populations, including children in the hospital, those with HIV infection or other immunocompromise, and those in the developing world, require special consideration. Most children do well, compared to adults with FUO, but true FUO is not always a benign condition, necessitating the best care a health care provider can offer.

Clinical spectrum of fever of unknown origin among Indian children

BACKGROUND

Fever of unknown origin (FUO) is an important cause of morbidity and mortality in children, especially in tropical and developing countries.

AIM

To determine the aetiology and outcome of FUO in Indian children.

METHODS

A hospital-based, prospective, observational study was conducted over a 1-year period (2006-2007). Children aged > or =3 months to 12 years who qualified for the definition of FUO were recruited. Initial evaluation included complete blood count, peripheral smear for malarial parasites, erythrocyte sedimentation rate (ESR), urine analysis and culture, blood culture, tuberculin test and chest X-ray.

RESULTS

Of 49 patients evaluated, a diagnosis was reached in 43 (88%). Infections were the predominant cause of FUO in 34 patients (69%). Enteric fever was the most common infection (14), followed by visceral leishmaniasis (10) and tuberculosis (5). The next most common cause was malignancy (6, 12%). Among the six undiagnosed patients, spontaneous resolution occurred in five whereas one child continued to be febrile without an established cause at the end of the study.

CONCLUSION

Repeated, thorough clinical examination and carefully selected laboratory examinations proved useful in the diagnosis of FUO. Serology (e.g. enteric fever) and bone marrow examination (e.g. leishmaniasis, malignancy) were the most useful diagnostic tests.

Referral and previous care of children with meningitis in Nigeria: implications for the presentation and outcome of meningitis in developing countries

There is a paucity of data on the referral of children with meningitis in developing countries, and on the relationship of presentation and outcome to previous care. Referral and previous care were investigated in 281 post-neonatal children treated in two tertiary centres. Data were obtained through the review of referral notes from orthodox health facilities, interview of parents/guardians and review of admission notes. Forty-four (16%) children were facility-referred and 81 (29%) self-referred from orthodox facilities while 156 (55%) were self-referred without previous care in these facilities. The facility-referrals (n=44) included 19 (43%) with meningitis on treatment, 13 (30%) with suspected meningitis and 12 (27%) with unsuspected meningitis. Twenty-two (50%) were referred because of deterioration, partial response or non-response to treatment, 5 (11%) on request by the parents, 9 (21%) on the suspicion of meningitis or other neurological disorder and 7 (16%) for mixed reasons. No reason was given in 1 case of meningitis on treatment. Among the 19 children referred with meningitis on treatment, only 1 was referred within 24 h of diagnosis, a confirmatory lumbar puncture was done only in 7, and only 10 of 18 (no data in 1 case) were on reasonably appropriate antibiotic regimens. Previous care in orthodox facilities was significantly associated with delayed presentation (>3 days of illness, p<0.001), partial treatment (p<0.001), lack of typical signs (p<0.05), severe illness (p<0.01), and adverse outcome (death or recovery with neurological sequelae, p<0.05). Limited recognition of the possibility of meningitis in acutely ill children and an inadequate referral practice may account for these effects. A clear delineation of referral needs might reduce the magnitude of these problems.

Pyrexia of unknown origin in children: a review of 102 patients from Turkey

Pyrexia of unknown origin (PUO) has not been appropriately investigated in Turkish children and therefore a study was undertaken to determine the causes of PUO and to evaluate which clinical procedures are useful in establishing a diagnosis. A total of 102 children fitting the classical PUO criteria seen in our clinic between 1995 and 2002 were investigated retrospectively. Infections, collagen vascular disorders, malignancy and miscellaneous conditions constituted 44.2%, 6.8%, 11.7% and 24.5% of cases, respectively, while 12.8% of the cases remained undiagnosed. Enteric fever, brucellosis and respiratory tract infections were the most commonly encountered infections, whereas familial Mediterranean fever was the commonest non-infectious disorder. Biopsy, aspiration, serology, bacteriology, radiology and observation of the clinical course were the most useful diagnostic procedures.

Evaluation of 80 children with prolonged fever

BACKGROUND

Several studies have been published regarding the etiology and evaluation of a child with prolonged fever, however, the reasons for the prolonged fever have changed during the years. The present study aims to determine the causes of prolonged fever, to investigate the relationship of fever using some basic laboratory tests, and to establish guidelines for the approach in those children.

METHODS

The charts of 80 out of 17490 hospitalized children who were seen between 1996 and 2001 with prolonged fever of longer than 2 weeks and unknown origin were reviewed in the university hospital of Izmir, Turkey. Their charts were evaluated in respect of age, sex, growth curves, educational level of their families, the duration and the magnitude of fever, causes of fever, and basic laboratory investigations such as white blood cell, blood smear, hemoglobin, erythrocyte sedimentation rate, and C-reactive protein.

RESULTS

Forty-four (55.00%) were boys and 36 (45.00%) were girls. Forty-four children (55.00%) were aged between 1 month and 2 years, 21 (26.25%) were aged 3-6 years, seven (8.75%) were aged 7-10 years, and eight (10.00%) were older than 10 years. The mean age was 3.87 +/- 4.17 years (range 3 months-17 years). Forty-six children (57.50%) had a prolonged fever that had lasted from 15-30 days, 18 (22.50%) from 31-60 days, and 16 (20.00%) had fever lasting more than 60 days. Final diagnosis had been reached in 70 of the 80 children (87.50%). The most common causes were infection (47/80), followed by immune deficiency (6/80), collagen tissue disorder (5/80), neoplasia (2/80), and miscellaneous (10/80) such as central fever in three, diabetes insipidus in two, familial Mediterranean fever in two, Kawasaki disease, foreign body in the respiratory system, and Crohn disease in one patient each. Among the laboratory tests white blood cell count, hemoglobin level and blood smear distribution of infection group were statistically significant.

CONCLUSIONS

The most common cause of fever of unknown origin remains infection. The proportion of collagen tissue disorders and neoplasia have been found to be decreased. Unusual reasons such as diabetes insipidus and foreign body in the respiratory system in the miscellaneous group have been detected. Age plays important role in the diagnosis of prolonged fever, while some basic laboratory tests might give clues in the evaluation and may suggest a diagnosis.