Current Trends in Diagnostics of Viral Infections of Unknown Etiology

Viruses are evolving at an alarming rate, spreading and inconspicuously adapting to cutting-edge therapies. Therefore, the search for rapid, informative and reliable diagnostic methods is becoming urgent as ever. Conventional clinical tests (PCR, serology, etc.) are being continually optimized, yet provide very limited data. Could high throughput sequencing (HTS) become the future gold standard in molecular diagnostics of viral infections? Compared to conventional clinical tests, HTS is universal and more precise at profiling pathogens. Nevertheless, it has not yet been widely accepted as a diagnostic tool, owing primarily to its high cost and the complexity of sample preparation and data analysis. Those obstacles must be tackled to integrate HTS into daily clinical practice. For this, three objectives are to be achieved: (1) designing and assessing universal protocols for library preparation, (2) assembling purpose-specific pipelines, and (3) building computational infrastructure to suit the needs and financial abilities of modern healthcare centers. Data harvested with HTS could not only augment diagnostics and help to choose the correct therapy, but also facilitate research in epidemiology, genetics and virology. This information, in turn, could significantly aid clinicians in battling viral infections.

Combined Laboratory Approach to Detection of Parvovirus B19 and Coxiella Burnetii in Patients with Fever of Unknown Origin

BACKGROUND

Fever of unknown origin (FUO) is one of the greatest challenges for clinicians and patients. There are more than 200 etiological agents of FUO, among these the most common is the role of infection, neoplasms, and diseases of connective tissue. The aim of the present study is to investigate the role of the infectious agents parvovirus B19 (B19V) and Coxiella burnetii (C. burnetii) in the development of fever of unknown origin by a set of immunoenzymatic and molecular methods.

METHODS

The present study included a total of 70 adult patients diagnosed with FUO and hospitalized in Bulgarian Hospitals. A control group of 26 healthy people were also included. Serological (indirect enzyme immunoassay test for detection of B19V and C. burnetii Ph. II specific IgM/IgG) and molecular (extraction and detection of infectious nucleic acids) methods were used.

RESULTS

From all patients with FUO, a positive result for B19V-IgM was obtained in 18/70 (25.71%, 95% CI: 15.47 - 35.95) and the highest percentage was found in age groups 0 - 9 and 10 - 19 years. Protective B19V immunity and past viral infection was reported in 41/70 (58.57%, 95% CI: 47.03 - 70.11), and this percentage corresponded with the control group 16/26 (61.54%, 95% CI: 42.84 - 80.24). Anti-C. burnetii Ph. II-IgM was demonstrated in 13/70 (18.57%, 95% CI: 9.46 - 27.68). A relatively high percentage of affected patients were ≤ 40 years. Anti-C. burnetii Ph. II-IgG was detected in 24/70 (34.29%, 95% CI: 23.17 - 45.41). The control group has a 100% negative result for acute B19V and C. burnetii infection. A positive B19V-DNA result was obtained in 12/70 (17.14%, 95% CI: 8.31 - 25.97) patients. In 11/12 (91.67%) it was in combination with positive B19V-IgM marker. Of the total 70 sera tested, a positive PCR results for C. burnetii-DNA were obtained in 11 (15.71%, 95% CI: 7.18 - 24.24). According to clinical manifestation and concomitant symptoms, a high percentage of B19V and C. burnetii positives were associated with FUO and fever, headache, chills, and rash.

CONCLUSIONS

It is of particular importance for a correct diagnosis of FUO to use a combined laboratory approach to prove acute or persistent infection and to test for a set of etiological agents.

Sera of Peruvians with fever of unknown origins include viral nucleic acids from non-vertebrate hosts

Serum samples collected from 88 Peruvians with unexplained fever were analyzed for viral sequences using metagenomics. Nucleic acids of anelloviruses, pegivirus A (GBV-C), HIV, Dengue virus, and Oropouche virus were detected. We also characterized from two sera the RNA genomes of new species of partitivirus and dicistrovirus belonging to viral families known to infect fungi or arthropod, respectively. Genomic DNA of a putative fungal cellular host could be PCR amplified from the partitivirus-containing serum sample. The detection in human serum of nucleic acids from viral families not known to infect vertebrates may indicate contamination during sample collection and aliquoting or human infection by their presumed cellular host, here a fungus. The role, if any, of the non-vertebrate infecting viruses detected in serum in inducing fever is unknown.

Etiology of Fever of Unknown Origin in Children from Mumbai, India

This descriptive study evaluated 49 children with fever lasting for more than 7 days at a tertiary hospital in urban Mumbai. Etiologic diagnosis could be established in 88% of the cases. Infections were the causein 34 (79%)patients, 6 (14%) were diagnosed as collagen vascular diseases, and 3 (7%) had other cause.

High Prevalence of Intermediate Leptospira spp. DNA in Febrile Humans from Urban and Rural Ecuador

Intermediate clusters may cause disease in areas where dengue and malaria are present, so differential diagnosis is necessary.

Leptospira spp., which comprise 3 clusters (pathogenic, saprophytic, and intermediate) that vary in pathogenicity, infect >1 million persons worldwide each year. The disease burden of the intermediate leptospires is unclear. To increase knowledge of this cluster, we used new molecular approaches to characterize Leptospira spp. in 464 samples from febrile patients in rural, semiurban, and urban communities in Ecuador; in 20 samples from nonfebrile persons in the rural community; and in 206 samples from animals in the semiurban community. We observed a higher percentage of leptospiral DNA–positive samples from febrile persons in rural (64%) versus urban (21%) and semiurban (25%) communities; no leptospires were detected in nonfebrile persons. The percentage of intermediate cluster strains in humans (96%) was higher than that of pathogenic cluster strains (4%); strains in animal samples belonged to intermediate (49%) and pathogenic (51%) clusters. Intermediate cluster strains may be causing a substantial amount of fever in coastal Ecuador.

Hantavirus infection: a neglected diagnosis in thrombocytopenia and fever?

Thrombocytopenia, fever, and acute renal failure are characteristic features of nephropathia epidemica, the predominant hantavirus infection in Europe. However, clinical presentation and blood cell counts may point to other disorders, such as a hematologic disease, particularly when impairment of renal function is not evident. This differential diagnosis often results in further extensive and unnecessary testing. We describe 3 patients with hantavirus infection with no renal failure, in whom a hematologic disorder was initially suspected. Serologic testing of hantavirus finally unraveled the mystery, and outcome of the patients was excellent. It is conceivable that similar cases often remain undiagnosed. Thus, testing for hantavirus should always be considered in cases of thrombocytopenia and fever of unknown origin, especially in areas endemic for the infection.

Evolution of the incidence and aetiology of fever of unknown origin (FUO), and survival in HIV-infected patients after HAART (Highly Active Antiretroviral Therapy)

BACKGROUND

Fever of unknown origin (FUO) is common among HIV-infected patients with a CD4+ T-lymphocyte cell count below 200 cells/ml. The use of HAART has transformed the evolution of AIDS and related diseases.

DESIGN AND METHOD

Case-control study, nested on a historical cohort of 3777 HIV-infected patients who were attended at "12 de Octubre" University Hospital in Madrid, Spain, between 1994 and 2000.

RESULTS

276 FUO episodes were recorded, 58 of which occurred in patients receiving HAART. The significant decrease on the accumulated FUO incidence along the study period of 7.3 episodes per 100 HIV-infected patients after 1997 corresponded with the introduction of HAART. FUO was more frequent in patients who did not receive HAART. The aetiological spectrum of FUO was transformed by the introduction of HAART: the incidence of tuberculosis decreased while that of leishmaniasis increased. The four year survival in the non-FUO group increased when compared to that of patients who had had FUO. Similarly, this four year survival increased in patients who received HAART at the time of FUO versus those not receiving it.

CONCLUSIONS

Our results confirm that the incidence of FUO has significantly decreased with the introduction of HAART. HAART has also transformed the aetiological spectrum related to FUO considerably. The most frequent cause of FUO in non-HAART patients on this study was the disseminated infection by Mycobacterium avium intracellulare (MAI), followed by tuberculosis, while leishmaniasis was its most common cause in patients receiving HAART. Survival decreased in patients who developed FUO; however, patients who received HAART at the time of FUO had longer survival than patients who did not.

Molecular characterization of adenoviral infections in Cuba: report of an unusual association of species D adenoviruses with different clinical syndromes

Adenoviruses are common pathogens that are responsible for a wide variety of infectious syndromes. The objectives of this study were to identify and characterize members of different adenovirus species at the molecular level and to describe the correlation between viruses and clinical syndromes during a period of 4 years. Between 2002 and 2006, 45 of 512 respiratory specimens (8%) from patients with acute respiratory tract infection tested positive for adenovirus. Four adenovirus isolates from samples sent for enterovirus isolation were also analyzed. This research identified 49 confirmed cases of human adenovirus infection by PCR and/or viral culture. The most common diagnosis was upper respiratory infection (44%). Human adenovirusD was the major species found (59%), followed by Human adenovirusC (36%) and Human adenovirusB (4%). Human adenovirus 5 was the major serotype found producing bronchiolitis, followed by human adenovirus 6. In patients with upper respiratory infection, the major serotype found was human adenovirus 17. Viruses of the species Human adenovirusD were identified in seven (77%) cases of acute febrile syndrome. Four isolates from clinical materials obtained from patients with encephalitis, acute flaccid paralysis and meningoencephalitis were identified as belonging to the species Human adenovirusD. Our data demonstrate a surprising result about the identification of an unusual association of viruses of the species Human adenovirusD with different clinical syndromes. This observation could be evaluated as a possible indicator of the emergence of a novel strain but further studies are required.

Primary cytomegalovirus infection in otherwise healthy adults with Fever of unknown origin: a 3-year prospective survey

BACKGROUND

Primary cytomegalovirus disease is probably still underestimated or missed in common clinical practice, and further prevalence studies should be performed, in particular in the setting of fever of under-determined origin (FUO) in adults.

PATIENTS AND METHODS

In a 3-year prospective survey of 123 consecutive adult patients referred for FUO often associated with a broad spectrum of constitutional signs and symptoms, 18 patients (14.6%) were found to have a primary cytomegalovirus infection, after a clinical, instrumental and laboratory workup.

RESULTS

In the majority of cases, this syndrome was consistently associated with altered white blood cell count, abnormal T-lymphocyte subsets and ultrasonography-confirmed hepatosplenomegaly. On the other hand, altered white blood cell differential and serum hepatic enzymes, and constitutional signs and symptoms were absent in 11.1-27.8% of cases, and an initial laboratory cross-reaction with anti-Epstein-Barr IgM antibodies was detected in 44.4% of episodes. Non-specific signs and symptoms were the only features in 27.8% of patients with adult cytomegalovirus disease, thus, confirming that this disorder may be still clinically underestimated, until virologic assays are performed. A prolonged and varied spectrum of subjective disturbances (similar to those encountered in infectious mononucleosis), which often limited daily activities, involved nearly 30% of subjects, and lasted for 3-15 months after recovery of acute cytomegalovirus disease.

CONCLUSION

In the clinical, laboratory, and instrumental workup for FUO, rapid recognition of a primary cytomegalovirus disease is useful to exclude alternative diagnoses, avoid non-necessary exposure to antibiotics, and reassure patients of their self-limiting, benign disorder.

Diverse genotypes of Kaposi's sarcoma associated herpesvirus (KSHV) identified in infant blood infections in African childhood-KS and HIV/AIDS endemic region

Kaposi's sarcoma-associated herpesvirus (KSHV or HHV-8) has been associated with several neoplasias, including childhood endemic Kaposi's sarcoma (KS). It is possible that strain genotypes could contribute to the differences in regional presentation (mainly sub-Saharan Africa), childhood infection, lack of male sex bias, distinct disseminated forms and rapid fatality observed for childhood endemic KS. Early studies, at the advent of the HIV/AIDS epidemic, identified only the K1-A5 genotype in childhood KS biopsies as well as blood of a few HIV positive and negative febrile infants in Zambia, a highly endemic region. This current enlarged study analyses blood infections of 200 hospitalized infants (6–34 months age) with symptoms of fever as well as upper respiratory tract infection, diarrhoea, rash or rhinitis. KSHV and HIV viraemia and were prevalent in this group, 22% and 39%, respectively. Multiple markers at both variable ends of the genome (K1, K12, and K14.1/K15) were examined, showing diverse previously adult-linked genotypes (K1 A2, A5, B, C3, D, with K12 B1 and B2 plus K14.1/K15 P or M) detected in both HIV positive and negative infants, demonstrating little restriction on KSHV genotypes for infant/childhood transmission in a childhood endemic KS endemic region. This supports the interpretation that the acquisition of childhood KSHV infections and subsequent development of KS are due to additional co-factors. J. Med. Virol. 79:1555–1561, 2007. © 2007 Wiley-Liss, Inc.

Serological evidence of arboviral infection and self-reported febrile illness among U.S. troops deployed to Al Asad, Iraq

Understanding the epidemiology of current health threats to deployed U.S. troops is important for medical assessment and planning. As part of a 2004 study among U.S. military personnel deployed to Al Asad Air Base, in the western Anbar Province of Iraq, over 500 subjects were enrolled, provided a blood specimen, and completed a questionnaire regarding history of febrile illness during this deployment (average approximately 4 months in country). This mid-deployment serum was compared to pre-deployment samples (collected approximately 3 months prior to deployment) and evaluated for seroconversion to a select panel of regional arboviral pathogens. At least one episode of febrile illness was reported in 84/504 (17%) of the troops surveyed. Seroconversion was documented in nine (2%) of deployed forces tested, with no association to febrile illness. Self-reported febrile illness was uncommon although often debilitating, and the risk of illness due to arbovirus infections was relatively low.

Discovery of a novel human picornavirus in a stool sample from a pediatric patient presenting with fever of unknown origin

Fever of unknown origin (FUO) is a serious problem in the United States. An unidentified agent was cultured from the stool of an infant who presented with FUO. This virus showed growth in HFDK cells and suckling mice. Using DNase sequence-independent single-primer amplification, we identified several nucleotide sequences with a high homology to Theiler's murine encephalomyelitis virus. Nearly full-length viral genome sequencing and phylogenetic analysis demonstrate that this virus is a member of the Cardiovirus genus of the Picornaviridae family.

Cytomegalovirus esophagitis in a child with human immunodeficiency virus-1 infection presenting as fever of unknown origin and stunted growth

We report a 12-year old boy with human immunodeficiency virus-1 infection and cytomegalovirus-associated esophagitis, who presented with an indolent clinical course associated with fever of an unknown origin, failure to thrive and weight loss.

[Screening of adult patients with fever of unknown origin. A prospective study on the role of primary cytomegalovirus infection]

PATIENTS AND METHODS

In a three-year prospective survey of 135 consecutive adult patients referred for fever of unknown origin often associated with a broad spectrum of constitutional signs and symptoms, 21 (15.5%) were found to have a primary Cytomegalovirus infection.

RESULTS

In the majority of cases, this syndrome was consistently associated with altered white blood cell count, abnormal T-lymphocyte subsets and hepatosplenomegaly. On the other hand, altered white blood cell differential and serum hepatic enzymes, and constitutional signs and symptoms were absent with a rate ranging from 11.1% to 27.4% of cases, and an initial laboratory cross-reaction with anti-Epstein-Barr IgM antibodies was detected in 48.1% of episodes. Non-specific signs and symptoms were the only features in 27.4% of patients, thus confirming that this disorder may be still clinically underestimated in its real frequency, until virologic assays are carried out. An extensive and varied spectrum of subjective disturbances, sometimes of duration prolonged beyond six months involved nearly 30% of subjects, and lasted for 3-15 months after recovery of acute, primary Cytomegalovirus disease.

CONCLUSIONS

In a multidisciplinary (clinical, laboratory, and instrumental) workup for a fever of unknown origin, a rapid recognition of a primary Cytomegalovirus disease is useful to exclude alternative diagnoses, avoid unnecessary exposure to antimicrobial agents, and reassure patients of the benign and self-limiting course of their illness.

Lethal cytomegalovirus ischemic colitis presenting with fever of unknown origin

We report a fatal case of cytomegalovirus (CMV) ischemic colitis in a renal transplant recipient. The disease was manifested with fever of unknown origin for 27 days followed by progressive right lower abdominal pain. The clinical condition deteriorated rapidly with development of disseminated intravascular coagulopathy and internal bleeding despite right hemicolectomy and antiviral therapy. The patient died 11 days after the onset of abdominal pain. We conclude that the possibility of CMV ischemic colitis should be suspected if a patient presents with fever and abdominal pain in the early months after transplantation, and that early viral detection by CMV polymerase chain reaction can be lifesaving.

Fever in the recently returned HIV infected traveller

A 41 year old HIV infected man with an extensive travel history developed intermittent fever and weight loss shortly after returning from abroad. Extensive and prolonged investigation identified the cause.

Etiologies of acute undifferentiated febrile illness in Thailand

BACKGROUND

Acute pyrexia of unknown origin (Acute PUO) was reported to affect approximately 200,000-400,000 patients each year reported by the national Annual Epidemiological Surveillance Report. The patients usually present with fever of less than two-week duration and non-specific symptoms such as malaise, myalgia, headache and loss of appetite. Its mortality rate is less than 0.02 percent. It would be interesting to find the etiologies and propose a management plan if the etiologies are discovered.

OBJECTIVE

This prospective epidemiologic study aimed to discover the etiologies of acute undifferentiated febrile illness in a tropical region like Thailand.

SUBJECTS AND METHOD

Ten community-based hospitals were chosen as representatives in each part of Thailand to enroll patients into the study. Patients aged over two years old who presented with fever at the participating hospitals during year 1991-1993 were eligible for the study. Entry criteria of acute undifferentiated febrile illnesses (AUFI) included oral temperature over 38.3 degrees C within the last 24 hours, duration of fever ranging from 3-14 days, no specific single organ involvement by history taking and physical examination, normal or non-specific results of the following investigations: complete blood count, thick film for malaria, urinalysis and chest roentgenogram. The patients were hospitalized and a preset diagnostic protocol was performed. Other diagnostic procedures deemed necessary by attending physicians were perform. Patients were followed up within one month after hospital discharge.

RESULTS

1,240 patients were enrolled but only 1,137 case records and results of the serological tests were available for analysis. Etiologies could be found in 471 cases (38.7%). Primary bacteremia was detected in 36 cases (3.2%). E. coli, streptococci, salmonella, Enterobacter spp. and S. aureus were the five most common blood isolates. Serological studies revealed positive results for scrub typhus (7.5%), influenza (6.0%), dengue fever (5.7%), murine typhus (5.3%), enteric fever (1.9%), chikunkunya infection (1.1%), leptospirosis (1.1%) and melioidosis (0.9%). Thirteen cases succumbed (1.1%) in this study.

CONCLUSION

The etiologies in the majority (61.3%) of AUFI remained unknown. Rickettsial infection, influenza and dengue fever are the most common identifiable diseases in a tropical country like Thailand especially during the rainy season. A management guideline for diagnosis and treatment of the AUFI with emphasis on primary bacteremia and antimicrobial-treatable AUFI was proposed.

Human cytomegalovirus, human herpesvirus-6 and human herpesvirus-7 in neutropenic patients with fever of unknown origin

OBJECTIVE

To investigate the appearance of cytomegalovirus (CMV) DNA, human herpesvirus-6 (HHV-6) DNA and human herpesvirus-7 (HHV-7) DNA in plasma as a sign of reactivation and possible causes of fever of unknown origin (FUO) during neutropenia.

METHODS

From 134 patients with febrile neutropenia following cytotoxic chemotherapy during the years 1996-2000, 20 severely neutropenic patients (granulocyte count < 0.1 x 109/L) were selected. Ten were patients with bacteremia and ten were patients with FUO. Five samples from each patient were selected at the start of chemotherapy, at the time of blood culture and fever, after 24 and 48 hours of fever, and, finally, after two to three days without fever. Virus DNA was detected by real-time quantitative and nested polymerase chain reaction (PCR).

RESULTS

CMV-DNA was detected in two out of ten FUO-patients in all samples drawn during fever. From another FUO and during two bacteremia episodes, CMV-DNA was detected after 48 hours of fever. DNA from HHV-6 and HHV-7 was not detected in any of the 20 febrile episodes.

CONCLUSIONS

HHV-6 and HHV-7 as a possible explanation for FUO in severely neutropenic patients treated with cytotoxic chemotherapy seems not be very likely. However, CMV was identified in 5/20 patients and the febrile episodes in the two FUO-patients with constant DNA-emia may have been caused by a reactivation of CMV. This implies that CMV infection can be expected not only in transplant patients but also in chemotherapy-treated neutropenic patients.

[Young child with fever of unknown origin in the 'post Haemophilus influenzae era']

A 2.5-year-old boy and a 2-month-old girl presented with fever without an apparent source. Additional laboratory tests were requested due to alarming signs for the presence of a serious bacterial infection. Pneumonia and viral meningitis respectively were diagnosed, and adequate therapy led to a quick and complete recovery. Due to changing prospects following the near eradication of invasive Haemophilus influenzae type b (Hib) infections by vaccination, there are no suitable guidelines at present concerning fever without an apparent source in children. A selection of patients at risk can first of all be made based on patient history and a physical examination and secondly by carrying out additional laboratory tests. Furthermore, careful evaluation, clinical acumen, well-informed parents and observation are all important elements in the treatment of these patients.

[Detection of viral aetiology in cerebral spinal fluid samples from 580 clinical cases]

OBJECTIVE

To investigate the viral aetiology in cerebral spinal fluid (Csf) from 580 cases of CNS infection or FUO in Yuedong district from 1990 to 1997.

METHODS

Virus isolation was done with Hep-2 and BHK-21 cells.

RESULTS

21 virus types of 5 kinds of viruses were isolated from 113 samples (19.5%). Clinically diagnosed diseases included viral encephalitis 17.8% (43/242), intracranial infection 20.2% (47/233), paralytic diseases 24.3% (9/37), FUO 37.5% (9/24), convulsion 16.0% (4/25), Guillain-Barre syndrome 5.3% (1/19). Virus infection included 11 cases of Poliovirus (constitutional ratio 0.0973, including 1 Polio-I, 8 Polio-II, 2 Polio-III); 54 cases of Coxsackie virus (0.477 9, including 11 CoxA24, 10 CoxBl, 2 Cox134, 3 CoxB5); 15 cases of ECHO virus (0.1327, including 4 ECHO-24, 3 ECRO-7, 2 ECHO-12 and each one of ECHO-3, 11,14,15,27,32); 25 cases of Enterovirus (0.2213, including 14 EV-70, 11 EV-71); 8 cases of Adenovirus (0.070 8, including 3 Adv-2, 3 Adv-3 and 2 Adv7). Results of different age groups indicated there was significant difference (P < 0.05) in virus detection rate in two age groups. Virus positive rates in different years were 1990-1991 14.2% (15/106), 1992-1993 14.1%(23/163), 1994-1995 26.1% (36/138), 1996-1997 22.5% (39/173), that showed a significant difference (P <0.05).

CONCLUSIONS

Virus infection rate of CNS diseases and FUO showed an a ascending trend, and the different virus types and kinds were isolated in different periods.

Clinical and laboratory findings in immunocompetent patients with persistent parvovirus B19 DNA in bone marrow

The clinical relevance of parvovirus B19 DNA persistence in bone marrow was examined in 10 immunocompetent individuals undergoing examinations for unexplained fever, arthralgia or chronic leukopenia. Common causes of these symptoms had been ruled out and bone marrow aspiration was indicated at this stage of investigation. In addition to morphological analysis of the bone marrow, a test for B19 DNA was performed with 2 nested PCRs. Five of these 10 selected patients had detectable B19 DNA in their bone marrow, whereas no viraemia was observed. Additional bone marrow samples were collected at least 6 months after the first sample from the B19 DNA-positive patients, of whom 3 were found to be still positive. Indeed, 2 of the patients have been positive for more than 5 y of follow-up. Sera from all patients with persistent B19 DNA in bone marrow could neutralize the virus. One patient responded to treatment with immunoglobulin but later relapsed. No other cause of the symptoms was found, despite extensive investigations, and at least some of the prolonged disease manifestations may be due to parvovirus B19.

Epstein-Barr virus--Associated hemophagocytic syndrome. A cause of fever of unknown origin in human immunodeficiency virus infection

A 26-year-old human immunodeficiency virus-positive man presented with fever of unknown origin, pancytopenia, and elevated liver function tests. Numerous diagnostic tests and empiric therapeutic interventions remained unsuccessful. Splenectomy eventually established the diagnosis of Epstein-Barr virus-associated hemophagocytic syndrome. Treatment with foscarnet, acyclovir, prednisone, and vinblastine resulted in complete recovery. Three months later, Hodgkin's disease, a previously reported complication of the Epstein-Barr virus-associated hemophagocytic syndrome, was diagnosed. Fever, pancytopenia, and hepatic dysfunction are common complication of advanced human immunodeficiency virus infection and can be caused by a variety of opportunistic pathogens. A high index of suspicion is critical for the management of this otherwise fatal disorder because once the diagnosis is made, even patients with advanced disease benefit from aggressive therapeutic intervention, as demonstrated in the case presented.

Respiratory virus infections during anticancer treatment in children

To evaluate the occurrence and clinical significance of respiratory virus infections in children during anticancer treatment, we studied 75 consecutive episodes of febrile infection in 32 children during 17 months. Viral antigen detection for 7 respiratory viruses, viral culture for rhinoviruses and enzyme immunoassay serology were used. Evidence for respiratory virus infection was found in 28 (37%) cases. Rhinovirus was the most common virus detected in 13 (17%) episodes. The other etiologic agents were respiratory syncytial virus (6 episodes), parainfluenza virus type 3 (5 episodes), adenovirus (4 episodes), influenza A virus (3 episodes), and influenza B virus (1 episode). Respiratory virus infections were diagnosed as often in leukopenic as in non-leukopenic patients (37% vs. 38%). In 4 cases bacteremic infection was diagnosed. We found no difference in serum C-reactive protein values when episodes positive for respiratory viruses were compared with virus-negative episodes. Our observations show that respiratory virus infections are common in febrile children receiving anticancer treatment. Diagnostic tests for respiratory viruses should be used more often in evaluation of fever in these patients.

Arthropod-borne viral infections of man in Nigeria, 1964-1970

During the years 1964 to 1970, 171 arboviruses of 15 different types were isolated from humans in Nigeria. Isolation rates were highest in 1969, and lowest in 1965 and 1967. Monthly arbovirus activity was highest in the rainy season months of June, July and August and lowest in the dry months of January and February. Viruses were isolated from all age groups, with the majority from children one to four years old. The viruses isolated in largest numbers were chikungunya and yellow fever, which caused epidemics in 1969, and dengue types 1 and 2 and Tataguine, which are endemic in Ibadan. Bwamba virus was isolated in 1964 and 1969, and Bunyamwera group viruses were encountered for the first time in 1969. Other viruses recovered less frequently were Zika, Igbo-Ora (an agent related to o'nyong-nyong), two viruses related to the Uganda mosquito virus Ug MP 359, Dugbe, Thogoto, Lebombo and Shuni. Several of these are new agents and have not previously been isolated from man. Clinical details are presented where available.

Febrile illness in early infancy associated with ECHO virus infection

Twenty-three infants less than six weeks of age with fever of 100.4 degrees F, or higher and no evidence of bacterial infection were seen at the Cincinnati General Hospital from July to December, 1971. Seventeen of these were admitted to the hospital; 15 were treated with penicillin and kanamycin for possible sepsis. Viral isolation was attempted on 21 of these infants, and ECHO viruses were isolated from 14 (66.7 per cent), compared to three (14.3 per cent) of 21 controls. Eleven of the 14 ECHO viruses isolated were type 4, and the other 3 were types 6, 11, and 25 respectively. Acute and convalescent serum was obtained from 11 of the 21 infants; seven had a fourfold rise in antibody to ECHO virus type 4. Most of the children had fever with irritability, six of the 23 had a fine maculopapular rash, and three had aseptic meningitis. This study suggests that ECHO viruses may be a significant cause of febrile illness in young infants during the summer and fall and may account for illnesses which lead to hospitalization as possible sepsis.