Global knowledge gaps in acute febrile illness etiologic investigations: A scoping review

Epstein-Barr Virus in the RIVERA Case-Control Study of Acute Febrile Illness: Acute Mononucleosis Nearly Absent as an Etiology in the Peruvian Amazon

Large diagnostic panels allow for pathogens with high or low likelihood of causing attributable illness to be tested simultaneously. Infectious mononucleosis (IM) due to primary infection with Epstein-Barr virus (EBV) is a common cause of acute febrile illness (AFI) in case series from high-income countries, though its contribution to AFI in tropical low-income settings is unclear. As part of a case-control study using multiplex quantitative polymerase chain reaction (qPCR) diagnostics, we set out to determine if primary EBV infection was an underrecognized cause of AFI in the Peruvian Amazon. Presence of EBV DNA in whole-blood samples was equally prevalent among febrile cases and afebrile controls (34.6% [247/714] versus 35.7% [248/695]) and was not correlated with classic IM symptoms. Given the clear lack of clinical significance of the whole-blood PCR results, additional testing was pursued to ascertain the true prevalence of IM among cases of AFI in this population. The presence of EBV DNA in plasma, a marker of active EBV-related processes, was detected in 7% (5/68). Anti-EBNA-1 IgG, a late marker of prior infection, was tested via ELISA and detected in 4/5 of the plasma-positive patients, thereby excluding an acute primary EBV infection in all but one patient. Infectious mononucleosis due to primary infection with EBV was not an important etiology of AFI in the Peruvian Amazon, despite high rates of initial test positivity.

Antibiotic prescribing patterns at outpatient clinics in Western and Coastal Kenya

Antimicrobial resistant pathogens are a leading cause of morbidity and mortality worldwide, with overuse and misuse of antimicrobials being key contributors. We aimed to identify factors associated with antibiotic prescriptions among patients presenting to clinics in Kenya. We performed a retrospective, descriptive cohort study of persons presenting to outpatient clinics in Western and Coastal Kenya, including symptoms, physical exams, clinician assessments, laboratory results and prescriptions. We reviewed 1,526 visits among 1,059 people who sought care from December 2019-February 2022. Median age was 16 (IQR 6-35) and 22% were under 5. 30% of malaria RDTs were positive and 3% of dengue RT-qPCRs were positive. Antibiotics were prescribed in 73% of encounters overall and in 84% among children under 5. In 48% of visits antibiotics were prescribed without a provisional bacterial diagnosis. In the multivariable model, factors associated with increased odds of an antibiotic prescription were the clinic in Western Kenya (OR 5.1, 95% CI 3.0-8.8), age less than or equal to 18 (OR 2.1, 95% CI 1.4-3.2), endorsement of cardiorespiratory symptoms (OR 5.2, 95% CI 3.2-8.3), a negative malaria RDT (OR 4.0, 95% CI 2.5-6.8), and a provisional diagnosis that could be bacterial in etiology (OR 5.9, 95% CI 3.5-10.3). High rates of antibiotic prescriptions are common even when associated diagnoses are not bacterial. Compared to our 2014-2017 cohort, we found higher rates of antibiotic prescriptions among children. Improved diagnostics to rule in alternative diagnoses as well as stewardship programs are needed.

TaqMan Array Card real-time polymerase chain reaction panel to detect pathogens in whole blood of febrile inpatients in northern Tanzania, 2016-2019

BACKGROUND

Acute febrile illness is a common reason for seeking healthcare in low- and middle-income countries. We describe the diagnostic utility of a TaqMan Array Card (TAC) real-time polymerase chain reaction (PCR) panel for pathogen detection in paediatric and adult inpatients admitted with febrile illness.

METHODS

In this prospective cohort study, we screened medical admissions for a tympanic temperature ≥38.0°C or reported fever within 72 h and used a PCR panel to detect pathogens, including bacteria, viruses, fungi and protozoa, in 697 participants. We compared PCR results to conventional diagnostic methods and considered PCR detections as the cause of fever, except for Plasmodium spp. and Schistosoma spp. Participants for PCR testing was consecutively selected from the end of enrolment.

RESULTS

Of 1132 participants enrolled in the cohort, 697 (61.6%) were tested by PCR. Median (IQR) age was 29.6 (4.6-46.4) years. Three hundred seventy-eight (54.2%) were male. The PCR method improved illness identification, increasing diagnostic yield from 73 (10.5%) by conventional methods to 124 (17.8%) of 697 participants. PCR detections included four viral pathogens: dengue (n = 1), enterovirus (n = 7), measles (n = 1) and Rift Valley Fever Virus (RVFV) (n = 3). Forty-six bacterial pathogens were detected in 44 (6.3%) participants, including fastidious bacteria such as Bartonella spp. (n = 2), Brucella spp. (n = 3), Coxiella burnetii (n = 2), Leptospira spp. (n = 1), M. tuberculosis (n = 7) and Rickettsia spp. (n = 9).

CONCLUSION

The PCR panel improved pathogen detection in febrile inpatients, providing clinically actionable results for fastidious bacteria and epidemiologically relevant findings like RVFV detections, when combined with conventional methods.

A clinicoepidemiological study of serologically diagnosed acute febrile illness in a teaching hospital, Kolkata

Introduction

Similar presenting manifestations in early phase and lack of awareness of aetiology of acute febrile illness (AFI) are major challenges in management of AFI.

Material and Methods

This was a retrospective observational cross-sectional study conducted in the Department of Microbiology, NRS Medical College, from 1 July 2022 to 30 June 2023 in serologically diagnosed febrile patients attending the outpatient department or admitted. Clinical and epidemiological data and laboratory parameters were recorded in a pretested structured questionnaire study tool, and collected data were analysed on MS-Excel sheets with various charts and tables.

Results

A total of 1711 serologically diagnosed febrile patients showed preponderance of dengue (38.3%), followed by leptospirosis (25%), scrub typhus (23.9%), malaria (12.6%), and enteric fever (1.92%). A majority of cases were male, less than 40 years of age, and from the rural population (73.2%), except in malaria (urban = 79.6%). The mean duration of fever was 9 days. Febrile cases were recorded maximum during the monsoon and postmonsoon periods (66.5%). The common manifestations are fever, headache (46.2%), pain abdomen (7.8%), nausea, and vomiting (9.4%). Thrombocytopenia with bleeding manifestation was higher in dengue (18%) cases. Mortality in dengue cases was recorded with multiorgan dysfunction syndrome (MODS). Scrub typhus cases showed seizure (8.3%) and altered sensorium (5%) due to fatal meningoencephalitis. Fatality in leptospirosis was mostly due to acute kidney injury (29.5%) and Weil's disease (4.4%).

Conclusion

Misdiagnosis or incorrect diagnosis and delay in initiation of appropriate treatment results in increased morbidity and mortality in AFI. Determination of epidemiological features and clinical manifestations of AFI along with timely correct diagnosis will benefit clinicians in proper treatment initiation, thereby reducing morbidity and mortality.

Demographic and Clinical Factors Associated with Bacterial or Nonbacterial Etiologies of Acute Undifferentiated Febrile Illness: Findings from a 3-Year Observational Study in Thailand, 2017-2020

Acute undifferentiated febrile illness (AUFI) is often undiagnosed in Thailand, resulting in delayed or ineffective treatment. We compared the demographic, exposure history, and clinical characteristics of AUFI patients with laboratory evidence of bacterial and nonbacterial pathogens. Patients aged 2-80 years presenting to 12 hospitals in Nakhon Phanom and Tak provinces were enrolled from April 2017 through May 2020. Interviews were conducted and blood, urine, and sputum were collected for culture as well as rapid diagnostic and molecular testing. A total of 1,263 patients tested positive for one or more bacterial, viral, or parasitic pathogens and were included in the analysis. Multivariable logistic regression was performed to compare factors associated with bacterial infections versus nonbacterial infections. Bacterial infections were more commonly identified in participants from Nakhon Phanom than Tak. Bacterial infections were independently associated with several factors including age ≥50 years (adjusted odds ratio [95% CI]): (4.18 [2.85-6.14]), contact with farm animals (1.82 [1.29-2.57]), antibiotic use within 72 hours of hospital presentation (2.37 [1.50-3.74]), jaundice (2.31 [1.15-4.63]), existing comorbidities (2.77 [1.93-3.96]), contact with febrile individuals (0.42 [0.31-0.57]), muscle pain (0.44 [0.31-0.64]), and rash (0.45 [0.29-0.70]). Bacterial infections were also associated with longer hospitalization (2.75 [2.08-3.64]) and lower odds of recovery at the time of discharge (0.14 [0.07-0.31]). Consideration of patient characteristics and signs/symptoms may help to inform targeted laboratory testing for suspected infectious etiologies. Understanding factors associated with bacterial and non-bacterial causes of AUFI may aid diagnosis and judicious use of antibiotics in resource-limited settings.

Acute febrile illness in Kenya: Clinical characteristics and pathogens detected among patients hospitalized with fever, 2017-2019

Acute febrile illness (AFI) is a common reason for healthcare seeking and hospitalization in Sub-Saharan Africa and is often presumed to be malaria. However, a broad range of pathogens cause fever, and more comprehensive data on AFI etiology can improve clinical management, prevent unnecessary prescriptions, and guide public health interventions. We conducted surveillance for AFI (temperature ≥38.0°C <14 days duration) among hospitalized patients of all ages at four sites in Kenya (Nairobi, Mombasa, Kakamega, and Kakuma). For cases of undifferentiated fever (UF), defined as AFI without diarrhea (≥3 loose stools in 24 hours) or lower respiratory tract symptoms (cough/difficulty breathing plus oxygen saturation <90% or [in children <5 years] chest indrawing), we tested venous blood with real-time PCR-based TaqMan array cards (TAC) for 17 viral, 8 bacterial, and 3 protozoal fever-causing pathogens. From June 2017 to March 2019, we enrolled 3,232 AFI cases; 2,529 (78.2%) were aged <5 years. Among 3,021 with outcome data, 131 (4.3%) cases died while in hospital, including 106/2,369 (4.5%) among those <5 years. Among 1,735 (53.7%) UF cases, blood was collected from 1,340 (77.2%) of which 1,314 (98.1%) were tested by TAC; 715 (54.4%) had no pathogens detected, including 147/196 (75.0%) of those aged <12 months. The most common pathogen detected was Plasmodium, as a single pathogen in 471 (35.8%) cases and in combination with other pathogens in 38 (2.9%). HIV was detected in 51 (3.8%) UF cases tested by TAC and was most common in adults (25/236 [10.6%] ages 18-49, 4/40 [10.0%] ages ≥50 years). Chikungunya virus was found in 30 (2.3%) UF cases, detected only in the Mombasa site. Malaria prevention and control efforts are critical for reducing the burden of AFI, and improved diagnostic testing is needed to provide better insight into non-malarial causes of fever. The high case fatality of AFI underscores the need to optimize diagnosis and appropriate management of AFI to the local epidemiology.

A toolkit for planning and implementing acute febrile illness (AFI) surveillance

Acute febrile illness (AFI) is a broad clinical syndrome with a wide range of potential infectious etiologies. The lack of accessible, standardized approaches to conducting AFI etiologic investigations has contributed to significant global gaps in data on the epidemiology of AFI. Based on lessons learned from years of supporting AFI sentinel surveillance worldwide, the U.S. Centers for Disease Control and Prevention developed the toolkit for planning and implementing AFI surveillance, described here. This toolkit provides a comprehensive yet flexible framework to guide researchers, public health officials, and other implementers in developing a strategy to identify and/or monitor the potential causes of AFI. The toolkit comprises a cohesive set of planning aids and supporting materials, including an implementation framework, generic protocol, several generic forms (including screening, case report, specimen collection and testing, and informed consent and assent), and a generic data dictionary. These materials incorporate key elements intended to harmonize approaches for AFI surveillance, as well as setting-specific components and considerations for adaptation based on local surveillance objectives and limitations. Appropriate adaptation and implementation of this toolkit may generate data that expand the global AFI knowledge base, strengthen countries' surveillance and laboratory capacity, and enhance outbreak detection and response efforts.

Next-generation sequencing survey of acute febrile illness in Senegal (2020-2022)

Introduction

Acute febrile illnesses (AFI) in developing tropical and sub-tropical nations are challenging to diagnose due to the numerous causes and non-specific symptoms. The proliferation of rapid diagnostic testing and successful control campaigns against malaria have revealed that non-Plasmodium pathogens still contribute significantly to AFI burden. Thus, a more complete understanding of local trends and potential causes is important for selecting the correct treatment course, which in turn will reduce morbidity and mortality. Next-generation sequencing (NGS) in a laboratory setting can be used to identify known and novel pathogens in individuals with AFI.

Methods

In this study, plasma was collected from 228 febrile patients tested negative for malaria at clinics across Senegal from 2020-2022. Total nucleic acids were extracted and converted to metagenomic NGS libraries. To identify viral pathogens, especially those present at low concentration, an aliquot of each library was processed with a viral enrichment panel and sequenced. Corresponding metagenomic libraries were also sequenced to identify non-viral pathogens.

Results and Discussion

Sequencing reads for pathogens with a possible link to febrile illness were identified in 51/228 specimens, including (but not limited to): Borrelia crocidurae (N = 7), West Nile virus (N = 3), Rickettsia felis (N = 2), Bartonella quintana (N = 1), human herpesvirus 8 (N = 1), and Saffold virus (N = 1). Reads corresponding to Plasmodium falciparum were detected in 19 specimens, though their presence in the cohort was likely due to user error of rapid diagnostic testing or incorrect specimen segregation at the clinics. Mosquito-borne pathogens were typically detected just after the conclusion of the rainy season, while tick-borne pathogens were mostly detected before the rainy season. The three West Nile virus strains were phylogenetically characterized and shown to be related to both European and North American clades. Surveys such as this will increase the understanding of the potential causes of non-malarial AFI, which may help inform diagnostic and treatment options for clinicians who provide care to patients in Senegal.

Coinfection of Malaria and Bacterial Pathogens among Acute Febrile Patients in Selected Clinics in Ghana

Malaria remains the leading cause of acute febrile illness (AFI) in Africa despite successful control measures and programs. Acute febrile illnesses can be misdiagnosed as malaria as a result of the overlapping spectrum of nonspecific symptoms or may not be pursued because of limited diagnostic capabilities. This study investigated potential etiologies of AFIs in Ghana and determined the relationship between coinfection between malaria and Q fever, leptospirosis, and culturable bacteria in febrile patients. Participants were enrolled between July 2015 and December 2019 from four Ghanaian military treatment facilities. Of the 399 febrile participants, 222 (55.6%) males and 177 (44.6%) females were enrolled. Malaria was diagnosed in 275 (68.9%) participants. Malaria coinfection occurred with leptospirosis, Q fever, and blood-cultured bacteria in 11/206 (5.3%), 24/206 (11.7%), and 6/164 (3.7%) participants, respectively. Among the 124 malaria-negative samples, the positivity rates were 4.1% (3/74), 8.1% (6/74), and 3.6% (2/56) for leptospirosis, Q fever, and bacterial pathogens isolated from blood culture, respectively. The majority of documented clinical signs and symptoms were not significantly associated with specific diseases. Approximately 10% of malaria-positive participants also had evidence suggesting the presence of a bacterial coinfection. Therefore, even in the case of a positive malaria test, other pathogens contributing to febrile illness should be considered. Understanding the frequency of malaria coinfection and other etiological agents responsible for AFIs will improve diagnosis and treatment and better inform public health knowledge gaps in Ghana.

Community-level incidence and treatment seeking during febrile illness: Insights from health behaviour surveys in rural Thailand and Laos

OBJECTIVE

Critical gaps remain in understanding community perceptions and treatment-seeking behaviours in case of fever. This is especially relevant considering global antimicrobial resistance, where fever is assumed to provoke non-judicious antibiotic use. Our study objective was therefore to document the community-level incidence of fever, the resulting treatment-seeking processes, and their underlying behavioural drivers.

METHODS

In a cross-sectional observational design, we used descriptive and inferential statistics and multivariable regression analysis to estimate the population-level incidence of fever and individual and socio-economic factors associated with treatment-seeking process characteristics. We utilised a detailed publicly available survey of community-level treatment-seeking behaviour (collected in 2017/2018), comprising a representative sample of 2130 rural adults in Thailand (Chiang Rai Province) and Lao PDR (Salavan Province).

RESULTS

Fever was reported by 7.1% of the rural adult population in Chiang Rai (95% CI: 5.1%-9.0%) and 7.5% in Salavan (95% CI: 4.5%-10.5%) during a 2-month recall period. Treatment-seeking patterns varied by socio-economic characteristics like precarious employment. 69.3% (95% CI: 60.8%-77.7%) of fever episodes involved access to formal (public/private) healthcare providers, 11.0% (95% CI: 4.5%-17.5%) involved informal providers, and 24.3% (95% CI: 16.6%-32.1%) took place without either formal or informal healthcare access. Febrile patients had on average 0.39 antibiotic use episodes when accessing formal healthcare settings, compared to 0.05 otherwise (p < 0.01).

CONCLUSION

Treatment-seeking behaviour during fever varies according to population characteristics. Clinical studies would benefit from contextualising quantitative outcomes. Treatment algorithms for non-malarial febrile illnesses should involve outreach to informal healthcare and community settings to support patients in precarious circumstances, and antibiotic resistance interventions should prioritise formal healthcare facilities.

First Report of Multiple Rickettsia sp., Anaplasma sp., and Ehrlichia sp. in the San Miguel Department of El Salvador from Zoonotic Tick Vectors

Neglected bacterial zoonoses are a group of Neglected Tropical Diseases (NTDs) that are commonly underdiagnosed and underreported due to their undifferentiated febrile illness symptomology. Spotted fever group rickettsioses (SFGR), a subset of tick-borne bacterial zoonoses, belong in this group. There is a dichotomy in the reporting and recognition of these pathogens in Central America: countries with reduced human development scores-like El Salvador-have little to no research or surveillance dedicated to these pathogens and the diseases they cause. This was the third-ever tick survey in El Salvador, highlighting the knowledge gap in this country. A total of 253 ticks were collected from 11 animals at two farm sites and one veterinary office. Standard and quantitative PCR were used to detect presence of SFGR, Ehrlichia, and Anaplasma sp. pathogens in ticks. Ehrlichia sp. were detected in 2.4% of all collected ticks and Anaplasma sp. were detected in 5.5% of all ticks. Rickettsia rickettsii was amplified in 18.2% of ticks, and amplicons similar to R. parkeri, and R. felis were found in 0.8% and 0.4%, of collected ticks, respectively. This is the first report of these pathogenic bacterial species in El Salvador. This study emphasizes the need for further surveillance and research including incorporating additional human seroprevalence and testing to understand the public health burden in this country.

Spatiotemporal overlapping of dengue, chikungunya, and malaria infections in children in Kenya

Malaria, chikungunya virus (CHIKV), and dengue virus (DENV) are endemic causes of fever among children in Kenya. The risks of infection are multifactorial and may be influenced by built and social environments. The high resolution overlapping of these diseases and factors affecting their spatial heterogeneity has not been investigated in Kenya. From 2014-2018, we prospectively followed a cohort of children from four communities in both coastal and western Kenya. Overall, 9.8% were CHIKV seropositive, 5.5% were DENV seropositive, and 39.1% were malaria positive (3521 children tested). The spatial analysis identified hot-spots for all three diseases in each site and in multiple years. The results of the model showed that the risk of exposure was linked to demographics with common factors for the three diseases including the presence of litter, crowded households, and higher wealth in these communities. These insights are of high importance to improve surveillance and targeted control of mosquito-borne diseases in Kenya.

Incorporating COVID-19 into Acute Febrile Illness Surveillance Systems, Belize, Kenya, Ethiopia, Peru, and Liberia, 2020-2021

Existing acute febrile illness (AFI) surveillance systems can be leveraged to identify and characterize emerging pathogens, such as SARS-CoV-2, which causes COVID-19. The US Centers for Disease Control and Prevention collaborated with ministries of health and implementing partners in Belize, Ethiopia, Kenya, Liberia, and Peru to adapt AFI surveillance systems to generate COVID-19 response information. Staff at sentinel sites collected epidemiologic data from persons meeting AFI criteria and specimens for SARS-CoV-2 testing. A total of 5,501 patients with AFI were enrolled during March 2020-October 2021; >69% underwent SARS-CoV-2 testing. Percentage positivity for SARS-CoV-2 ranged from 4% (87/2,151, Kenya) to 19% (22/115, Ethiopia). We show SARS-CoV-2 testing was successfully integrated into AFI surveillance in 5 low- to middle-income countries to detect COVID-19 within AFI care-seeking populations. AFI surveillance systems can be used to build capacity to detect and respond to both emerging and endemic infectious disease threats.

Antibody Prevalence and Risk Factors Associated with Rickettsia spp. in a Pediatric Cohort: SFGR Remains Underdiagnosed and Underreported in El Salvador

Spotted fever group rickettsioses (SFGR) are caused by a group of tick-borne pathogens that are increasing in incidence globally. These diseases are typically underreported and undiagnosed in low- and middle-income countries, and thus, have been classified as neglected bacterial pathogens. Countries with high poverty, low human development index score, and limited health infrastructure—like El Salvador in Central America—lack necessary surveillance for SFGR and other tick-borne pathogens. This paucity of baseline SFGR infection prevalence leaves vulnerable populations at risk of misdiagnosis. Further, tick-borne disease burdens in El Salvador are severely limited. To lay the foundation for tick-borne disease epidemiology in El Salvador, our team conducted two different enzyme-linked immunosorbent assays (ELISA) on banked human sera samples from a cohort of approximately 1000 pediatric participants from a high-risk vector-borne disease population. Eleven percent of all tested banked pediatric sera were positive for at least one ELISA assay at the time of enrollment: 10.7% were positive for only IgM antibodies (acute SFGR infection), and 2.5% were positive for IgG antibodies (a past SFGR infection). Older, male, children enrolled during the wet season, with a household history of infectious disease and higher maternal education level had higher odds of SFGR antibodies. Additionally, children from households with domestic poultry birds and previous knowledge of other vector-borne diseases had significantly reduced odds of SFGR antibodies. The large percentage of acute SFGR infections indicates that it continues to remain an underreported and undiagnosed issue in El Salvador and the Central American region. Much is still unknown regarding the complexity of the tick, animal host, and human host ecology transmission cycle of SFGR in El Salvador.

Acute febrile illness among outpatients seeking health care in Bangladeshi hospitals prior to the COVID-19 pandemic

Understanding the distribution of pathogens causing acute febrile illness (AFI) is important for clinical management of patients in resource-poor settings. We evaluated the proportion of AFI caused by specific pathogens among outpatients in Bangladesh. During May 2019-March 2020, physicians screened patients aged ≥2 years in outpatient departments of four tertiary level public hospitals. We randomly enrolled patients having measured fever (≥100.4°F) during assessment with onset within the past 14 days. Blood and urine samples were tested at icddr,b through rapid diagnostic tests, bacterial culture, and polymerase chain reaction (PCR). Acute and convalescent samples were sent to the Centers for Disease Control and Prevention (USA) for Rickettsia and Orientia (R/O) and Leptospira tests. Among 690 patients, 69 (10%) had enteric fever (Salmonella enterica serotype Typhi orSalmonella enterica serotype Paratyphi), 51 (7.4%) Escherichia coli, and 28 (4.1%) dengue detected. Of the 441 patients tested for R/O, 39 (8.8%) had rickettsioses. We found 7 (2%) Leptospira cases among the 403 AFI patients tested. Nine patients (1%) were hospitalized, and none died. The highest proportion of enteric fever (15%, 36/231) and rickettsioses (14%, 25/182) was in Rajshahi. Dhaka had the most dengue cases (68%, 19/28). R/O affected older children and young adults (IQR 8-23 years) and was detected more frequently in the 21-25 years age-group (17%, 12/70). R/O was more likely to be found in patients in Rajshahi region than in Sylhet (aOR 2.49, 95% CI 0.85-7.32) between July and December (aOR 2.01, 1.01-5.23), and who had a history of recent animal entry inside their house than not (aOR 2.0, 0.93-4.3). Gram-negative Enterobacteriaceae were the most common bacterial infections, and dengue was the most common viral infection among AFI patients in Bangladeshi hospitals, though there was geographic variability. These results can help guide empiric outpatient AFI management.

Etiology of acute febrile illnesses in Southern China: Findings from a two-year sentinel surveillance project, 2017–2019

Background

Southern China is at risk for arborvirus disease transmission, including Zika virus and dengue. Patients often present to clinical care with non-specific acute febrile illnesses (AFI). To better describe the etiology of AFI, we implemented a two-year AFI surveillance project at five sentinel hospitals in Yunnan and Guangdong Provinces.

Methods

Between June 2017 and August 2019, we enrolled patients between 2 and 65 years of age presenting at one sentinel hospital in Mengla County, Yunnan, and four in Jiangmen City, Guangdong, with symptoms of AFI (acute onset of fever ≥ 37.5°C within the past 7 days) without respiratory symptoms or diarrhea. Demographic, epidemiologic, and clinical information was obtained and entered into a web-based AFI surveillance database. A custom TaqMan Array card (TAC) was used to test patients’ whole blood specimens for 27 different pathogens using real-time polymerase chain reaction assays.

Results

During the two-year project period, 836 patients were enrolled; 443 patients from Mengla County and 393 patients from Jiangmen City. The median age was 33 years [range: 2–65], and most were hospitalized [641, 77%]. Of 796 patients with valid TAC results, 341 (43%) were positive for at least one of the 10 unique pathogens detected. This included 205 (26%) patients positive for dengue virus, 60 (8%) for Orientia tsutsugamushi, and 42 (5%) for Coxiella burnetii. Ten patients (1%) in Jiangmen City tested positive for malaria, 8 of whom reported recent travel outside of China. TAC results were negative for 455 (57%) patients. None of the patients had a positive TAC detection for Zika virus.

Conclusions

The project detected variability in the etiology of AFI in Southern China and highlighted the importance of differential diagnosis. Dengue, O. tsutsugamushi, and C. burnetii were the most frequently identified pathogens among enrolled AFI patients. As a non-notifiable disease, the frequent detection of C. burnetii is noteworthy and warrants additional investigation. The project provided a framework for routine surveillance for persons presenting with AFI.

Ending the Neglect of Treatable Bacterial Zoonoses Responsible for Non-Malaria Fevers

Bacterial zoonotic diseases such as leptospirosis, Q fever, melioidosis, spotted fever group rickettsioses, and brucellosis are increasingly recognized causes of non-malaria acute fevers. However, though readily treatable with antibiotics, these diseases are commonly misdiagnosed resulting in poor outcomes in patients. There is a considerable deficit in the understanding of basic aspects of the epidemiology of these neglected diseases and diagnostic tests for these zoonotic bacterial pathogens are not always available in resource-poor settings. Raising awareness about these emerging bacterial zoonoses is directly beneficial to the patients by allowing a test-and-treat approach and is essential to control these life-threatening diseases.

Pathogens causing acute febrile illness among children and adolescents in Burkina Faso, Madagascar and Sudan

Background

The etiology and optimal clinical management of acute febrile illness (AFI) is poorly understood.

Methods

Blood samples taken from study participants with acute fever (≥37.5°C) or a history of fever and recruited into the previous Typhoid Fever Surveillance in Africa (TSAP) study were evaluated using a polymerase chain reaction (PCR)-based TaqMan-Array Card designed to detect a panel of bacterial, viral, and parasitic pathogens. Clinical metadata were also assessed.

Results

A total of 615 blood samples available for analysis originated from Burkina Faso (n = 53), Madagascar (n = 364), and Sudan (n = 198) and were taken from participants ranging in age from 0–19 years. Through the TaqMan-Array Card, at least 1 pathogen was detected in 62% (33 of 53), 24% (86 of 364), and 60% (118 of 198) of specimens from Burkina Faso, Madagascar, and Sudan, respectively. The leading identified pathogen overall was Plasmodium spp., accounting for 47% (25 of 53), 2.2% (8 of 364), and 45% (90 of 198) of AFI at the respective sites. In Madagascar, dengue virus was the most prevalent pathogen (10.2%). Overall, 69% (357 of 516) of patients with clinical diagnoses of malaria, respiratory infection, or gastrointestinal infection were prescribed a World Health Organization guideline-recommended empiric antibiotic, whereas only 45% (106 of 237) of patients with pathogens detected were treated with an antibiotic exerting likely activity.

Conclusions

A PCR approach for identifying multiple bacterial, viral, and parasitic pathogens in whole blood unveiled a diversity of previously undetected pathogens in AFI cases and carries implications for the appropriate management of this common syndrome.

Trimethoprim-sulfamethoxazole Versus Azithromycin for the Treatment of Undifferentiated Febrile Illness in Nepal: A Double-blind, Randomized, Placebo-controlled Trial

Background

Azithromycin and trimethoprim-sulfamethoxazole (SXT) are widely used to treat undifferentiated febrile illness (UFI). We hypothesized that azithromycin is superior to SXT for UFI treatment, but the drugs are noninferior to each other for culture-confirmed enteric fever treatment.

Methods

We conducted a double-blind, randomized, placebo-controlled trial of azithromycin (20 mg/kg/day) or SXT (trimethoprim 10 mg/kg/day plus sulfamethoxazole 50 mg/kg/day) orally for 7 days for UFI treatment in Nepal. We enrolled patients >2 years and <65 years of age presenting to 2 Kathmandu hospitals with temperature ≥38.0°C for ≥4 days without localizing signs. The primary endpoint was fever clearance time (FCT); secondary endpoints were treatment failure and adverse events.

Results

From June 2016 to May 2019, we randomized 326 participants (163 in each arm); 87 (26.7%) had blood culture–confirmed enteric fever. In all participants, the median FCT was 2.7 days (95% confidence interval [CI], 2.6–3.3 days) in the SXT arm and 2.1 days (95% CI, 1.6–3.2 days) in the azithromycin arm (hazard ratio [HR], 1.25 [95% CI, .99–1.58]; P = .059). The HR of treatment failures by 28 days between azithromycin and SXT was 0.62 (95% CI, .37–1.05; P = .073). Planned subgroup analysis showed that azithromycin resulted in faster FCT in those with sterile blood cultures and fewer relapses in culture-confirmed enteric fever. Nausea, vomiting, constipation, and headache were more common in the SXT arm.

Conclusions

Despite similar FCT and treatment failure in the 2 arms, significantly fewer complications and relapses make azithromycin a better choice for empirical treatment of UFI in Nepal.

Clinical Trials Registration

NCT02773407.