Etiological analysis of acute respiratory infections in hospitalized children after the relaxation of COVID-19 non-pharmacological interventions in Quzhou, China (preprint)

Background: Acute respiratory infections (ARIs) can cause morbidity and mortality in children. This study was to determine the characteristics of pathogens in hospitalized children with ARIs after the relaxation of COVID-19 non-pharmacological interventions (NPIs) in Quzhou, China. Methods: Hospitalized children with ARIs were enrolled between May and October 2023, and thirteen common respiratory pathogens were tested by fluorescent quantitative polymerase chain reaction. Mono- and co-infections were assessed, and the association between pathogens and age was explored using restricted cubic spline analysis. Results: A total of 1225 children were included, 820 of them detected one pathogen and 238 of them detected two or more pathogens. Children aged 1-3 years had the highest positive detection rates. The dominant pathogen varied monthly. Mycoplasma pneumoniae (Mp) was the most common pathogen in monoinfection, followed by respiratory syncytial virus (RSV) and human rhinovirus (HRV), while influenza virus was detected at a lower rate. Mp+HRV was the most common combination of coinfections. The detection rates of Mp and HRV were higher in coinfections than in monoinfection, but there was no difference in the detection rate of RSV. In the restricted cubic spline models, a J-shaped association was consistently observed between age and Mp infection, the risk of HRV first increased and then decreased, the risk of RSV was relatively flat until 1.5 years and then decreased raplidly. Conclusion: Our study revealed the epidemiological characteristics of ARIs pathogens after the relaxation of NPIs. There is still a need to enhanced pathogen surveillance, especially for Mp.

SARS-CoV-2 Pandemic Non-Pharmacologic Interventions Temporally Associated with Reduced Pediatric Infections Due to Mycoplasma pneumoniae and Co-Infecting Respiratory Viruses in Arkansas (preprint)

Introduction: Non-pharmacologic interventions (NPIs), such as universal masking, implemented during the SARS-CoV-2 pandemic have reduced respiratory infections among children. This study focuses on evaluating the impact of NPIs on Mycoplasma pneumoniae infections in children, analyzing data from two hospitals in Arkansas, and examining age-related differences and coinfections with other viruses. Methods: The study was approved by the Institutional Review Board and included patients aged [≤]18 years with upper respiratory tract symptoms. Data from the FilmArray(R) Respiratory Panel (FARP) were collected and divided into pre-NPI and NPI periods for analysis. Total test positivity rate and interval change in the positivity rate were evaluated. Statistical differences were determined by Chi-square ({chi}-independence) analysis. Results: A total of 68,949 tests were performed with a statistical increase in testing during the NPI period. The overall test positivity rate for M. pneumoniae decreased by 74% (0.86% to 0.03%) during the NPI period, and the preschool age group had the highest number of positive tests in the pre- and NPI periods (Pre-NPI: n=40, NPI: n=12 positive tests, p=<0.001). The reduction in M. pneumoniae infections was consistent across age groups. Coinfections with other respiratory viruses, particularly human rhinovirus/enterovirus, were observed at much lower levels. Conclusions: NPIs effectively reduced M. pneumoniae in pediatric patients in Arkansas, and coinfections with specific viruses still occurred, albeit at lower levels during the SARS-CoV-2 pandemic. As NPIs are relaxed and the pandemic ends, we expect M. pneumoniae infections to return to pre-pandemic levels within the next 1-2 years.

Changes in Spectrum of Respiratory Pathogen Infections and Disease Severity Among Children in Hohhot: Impact of COVID-19 Prevention Measures (preprint)

Background Acute respiratory infections (ARIs) are caused by various pathogens, and the outbreak of the novel coronavirus has led to changes in the patterns of respiratory pathogen infections. Through long-term study of respiratory tract infection data in children from Hohhot, significant differences in the spectrum of respiratory pathogen infections, disease severity, and seasonal patterns have been discovered between 2022 and 2023.Methods Throat swabs were collected from 605 children with ARIs at the First Hospital of Hohhot, and pathogen detection was performed using microarray technology. Blood biomarkers, symptoms, and clinical diagnoses were evaluated.Results The study found that 56.03% of the patients were male, with an average age of 3.45 years. Pathogen dynamics revealed that SARS-CoV-2 was the most prevalent infection, accounting for 262 cases. It persisted from October 2022 to January 2023 and then disappeared. Influenza A virus (IAV) cases peaked in March 2023. Respiratory syncytial virus (RSV), Influenza B virus (IBV), Parainfluenza virus (PIV), Mycoplasma pneumoniae (M. pneumoniae), Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Group A streptococcus (GAS) were not detected after December 2022. The proportion of mixed infections was 41.94% among SARS-CoV-2 patients, while other pathogens had mixed infection rates exceeding 57.14%. Before December 2022, the mean value of white blood cell (WBC) count for Streptococcus pneumoniae (S. pneumoniae), Haemophilus influenzae (H. influenzae), Epstein-Barr virus (EBV), and Cytomegalovirus (CMV) was 8.83*10^9/L, C-reactive protein (CRP) was 18.36 mg/L, and procalcitonin (PCT) was 1.11 ng /ml. After December 2022, these values decreased to 5.5*10^9/L, 6.33 mg/L, and 0.24 ng /ml, respectively. Similarly, the proportion of patients with cough, difficulty breathing, and running nose, as well as the diagnosis of lower respiratory tract infections, decreased in December 2022. However, the situation was different for SARS-CoV-2 infections.Conclusions Strict SARS-CoV-2 policies reduced the infection risk for S. pneumoniae, H. influenzae, EBV, and other pathogens before November 2022. However, patient symptoms worsened compared to after November 2022, possibly due to an excessive focus on SARS-CoV-2, neglecting other diseases, and reduced population immunity to respiratory infections.

The clinical significance of macrolide resistance in pediatric Mycoplasma pneumoniae infection during COVID-19 pandemic.

Background: Mycoplasma pneumoniae (MP) is a commonly occurring pathogen causing community-acquired pneumonia (CAP) in children. The global prevalence of macrolide-resistant MP (MRMP) infection, especially in Asian regions, is increasing rapidly. However, the prevalence of MRMP and its clinical significance during the COVID-19 pandemic is not clear. Methods: This study enrolled children with molecularly confirmed macrolide-susceptible MP (MSMP) and MRMP CAP from Beijing Children's Hospital Baoding Hospital, Capital Medical University between August 2021 and July 2022. The clinical characteristics, laboratory findings, chest imaging presentations, and strain genotypes were compared between patients with MSMP and MRMP CAP. Results: A total of 520 hospitalized children with MP-CAP were enrolled in the study, with a macrolide resistance rate of 92.7%. Patients with MRMP infection exhibited more severe clinical manifestations (such as dyspnea and pleural effusion) and had a longer hospital stay than the MSMP group. Furthermore, abnormal blood test results (including increased LDH and D-dimer) were more common in the MRMP group (P<0.05). Multilocus variable-number tandem-repeat analysis (MLVA) was performed on 304 samples based on four loci (Mpn13-16), and M3562 and M4572 were the major types, accounting for 74.0% and 16.8% of the strains, respectively. The macrolide resistance rate of M3562 strains was up to 95.1%. Conclusion: The prevalence of MRMP strains in hospitalized CAP patients was extremely high in the Baoding area, and patients infected with MRMP strains exhibited more severe clinical features and increased LDH and D-dimer. M3562 was the predominant resistant clone.

Molecular epidemiology of Mycoplasma pneumoniae pneumonia in children, Wuhan, 2020-2022 (preprint)

Background Mycoplasma pneumoniae (M. pneumoniae) is an important pathogen of community-acquired pneumonia in children. However, prior to this study, there was a lack of research on the genotypes and macrolide resistance monitoring of M. pneumoniae in Wuhan. The factors contributing to the severity of illness caused by M. pneumoniaeinfection are still under investigation. We aimed to evaluate the clinical manifestations, genotypes, macrolide resistance, respiratory microenvironment, and their relationship with the severity of illness in children with M. pneumoniaepneumonia in Wuhan. Results Among 1,259 clinical samples, 461 samples were positive for M. pneumoniae via qPCR. We successfully identified the P1 genotypes of 127 samples based on metagenomic and Sanger sequencing, with P1-type 1 (113/127, 88.98%) being the dominant genotype. In addition, we identified the MLST genotypes of 67 samples, with ST-3 being the most common (60/67, 89.6%), followed by ST-14 (5/67, 7.4%) and ST-7 (2/67, 3%). No significant difference in pathogenicity was observed among different genotypes. The macrolide resistance rate of M. pneumoniaeisolates was 96% (48/50) and all mutations were A2063G in domain V of 23S rRNA gene. There was no significant difference between the upper respiratory microbiome of patients with mild and severe symptoms. The pan-genome analysis revealed that the genome of M. pneumoniae is highly conserved, with the core genome comprising 79% of the total genome length. In addition, the initial serological test cannot accurately diagnose M. pneumoniae infection. qPCR is suitable for detecting M. pneumoniaeinfection, while IgM titers greater than 1:160 can be used as a predictor of severity. Conclusions This study is the first to characterize the epidemic and genomic features of M. pneumoniae in Wuhan after the COVID-19 outbreak in 2020, which provides a scientific data basis for monitoring and infection prevention and control of M. pneumoniae in the post-pandemic era.

Analysis on the epidemic trend of respiratory pathogens in Guangzhou under non-pharmaceutical interventions during the COVID-19 pandemic (preprint)

Objective To analyze the epidemic trend of respiratory pathogens under non-pharmaceutical interventions during the COVID-19 pandemic in Guangzhou and to explore the causes. Methods Respiratory pathogens, namely influenza A virus (FluA), influenza B virus (FluB), respiratory syncytial virus (RSV), human parainfluenza virus (PIV), adenovirus (AdV), Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (Cpn), were selected from a total of 14549 patients from December 1, 2019 to November 30, 2022. The differences in the positive constituent ratios and detection rates of each pathogen were analyzed and compared among different years, ages, genders, and seasons. Results The detection rate of RSV (1.03%) was higher than that of FluA (0.42%), PIV (0.41%), MP (0.23%), AdV (0.10%), FluB (0.06%) and Cpn (0.01%), and the difference was statistically significant. There was a statistically significant difference between two comparisons of the detection rates of FluA in different years, with the lowest in 2021 (0%) and the highest in 2022 (1.32%). The detection rate of RSV in 2021 (0.80%) showed a decreasing trend compared to 2020 (1.43%). FluA replaced RSV in 2020 and 2021 as the dominant strain in 2022. The detection rates of RSV (5.21%), PIV (1.88%) and AdV (0.47%) in children were higher than those of 0.97%, 0.44% and 0.09% in young and middle-aged adults, respectively. They were also higher than 0.20%, 0.10% and 0.03% in the elderly, respectively, with statistically significant differences. The detection rate of FluA in children (0.89%) was higher than that in the elderly (0.36%), with a statistically significant difference. There was a statistically significant difference in the detection rates of RSV and PIV between young and middle-aged adults and the elderly. RSV was the predominant strain in both children and young and middle-aged adults, but it was replaced by FluA in the elderly. The detection rates of RSV (1.31%) and PIV (0.58%) were higher in female than in male (0.88% and 0.32%, respectively), and the differences were statistically significant. The predominant strain in both male and female was RSV. There were seasonal differences in the detection rates of FluA, RSV and PIV. The detection rate of FluA was highest in summer (1.34%), followed by winter (0.47%), spring and autumn were lowest, both were 0%. The detection rate of RSV was highest in autumn (2.19%), followed by summer (1.32%), spring and winter were lower (0.32% and 0.45%, respectively). The detection rate of PIV was highest in winter (1.01%), and 0.16%, 0.23%, and 0.21% in spring, summer, and autumn, respectively. The dominant strain was RSV in spring, summer and autumn, which was replaced by PIV in winter. Among the 13,270 patients who were screened for all seven of these pathogens simultaneously, the top four pathogen-positive composition ratios were RSV (41.54%), FluA (21.15%), PIV (18.46%) and MP (10.38%). Single pathogen infection was dominated by RSV infection, accounting for 0.81%, and two pathogen infections were dominated by FluA+PIV and RSV+ MP infection, with one case each. Conclusions RSV was more prevalent and Cpn was less common among respiratory pathogens infections in Guangzhou under non-pharmacological intervention during the New Coronavirus-19 pandemic. Annual differences existed in the detection rates of FluA and RSV. The detection rates of RSV and PIV were highest in children, followed by  young and middle-aged adults, and the elderly. The detection rates of RSV and PIV were higher in females than in males. There were seasonal differences in the detection rates of FluA, RSV and PIV, with the highest detection rates of FluA in summer, RSV in autumn and PIV in winter. Infection patterns were more common with single pathogens. The predominant strain was mostly RSV, except in 2022 and in the elderly was replaced by FluA, and was replaced by PIV in winter.

Comparison of respiratory pathogens in children with community-acquired pneumonia before and during the COVID-19 Pandemic (preprint)

Background Multifaceted non-pharmaceutical interventions during the COVID-19 pandemic have not only reduced the transmission of SARS-CoV2, but have had an effect on the prevalence of other pathogens. This retrospective study aimed to compare and analyze the changes of respiratory pathogens in hospitalized children with community-acquired pneumonia.Methods From January 2019 to December 2020, children with community-acquired pneumonia were selected from the Department of Respiratory Medicine, Shanghai Children's Medical Center. On the first day of hospitalization, sputum, throat swabs, venous blood samples from them were collected for detection of pathogens.Results A total of 2596 children with community-acquired pneumonia were enrolled, including 1871 patients in 2019 and 725 in 2020. The detection rate in 2020 was lower than in 2019, whether single or multiple pathogens. Compared with 2019, the detection rate of virus, especially parainfluenza virus, influenza virus and respiratory syncytial virus, all decreased in 2020. On the contrary, the prevalence of human rhinovirus was much higher than that in 2019. In addition, the positivity rate for bacteria did not change much over the two years, which seemed to be less affected by COVID-19. And Mycoplasma pneumoniae which broke out in 2019 has been in low prevalence since March 2020 even following the reopening of school.Conclusions Strict public health interventions for COVID-19 in China have effectively suppressed the spread of not only SARS-CoV2 but parainfluenza virus, influenza virus and Mycoplasma pneumonia as well. However, it had a much more limited effect on bacteria and rhinovirus. Therefore, more epidemiological surveillance of respiratory pathogens will help improve early preventive measures.

Impact of COVID-19 pandemic on the etiology and characteristics of community-acquired pneumonia among children requiring bronchoalveolar lavage in northern China (preprint)

Background: To investigate the etiology and clinical characteristics of community-acquired pneumonia (CAP) among children requiring bronchoalveolar lavage (BAL) and analyze the impact of the coronavirus disease 2019 (COVID-19) pandemic on the pathogen spectrum and clinical manifestations. Methods: Children <14 years old hospitalized with CAP requiring BLA were enrolled between February 2019 to January 2020 and August 2021 to July 2022. Multiplex reverse transcription polymerase chain reaction (mRT-PCR) was used for pathogen detection. The demographic and clinical characteristics were compared between different pathogen-type infection groups, and before and during the COVID-19 pandemic. Results: Pathogen was detected in 91.66% (1363/1487) children. Mycoplasma pneumoniae, adenovirus and human rhinovirus were the most frequently detected pathogens. The frequency of detection of virus infections and co-infections was decreased during the pandemic, but the detection of atypical bacterial infections was increased. The clinical manifestations and the results of CT scans and fiberoptic bronchoscopy showed a significant difference between different types of pathogen infection, and lung inflammation was reduced during the COVID-19 pandemic compared with before the pandemic. Conclusions: M. pneumoniae infection might be the greatest pediatric disease burden leading to CAP in northern China. Wearing masks and social distancing in public places during the COVID-19 pandemic effectively reduced the transmission of respiratory viruses, but it did not reduce the infection rate of M. pneumoniae. In addition, these interventions significantly reduced lung inflammation in children compared with before the pandemic.

The rapid diagnosis of Mycoplasma pneumonia using in situ hybridization on clinical samples.

The microbiological etiology of seasonal upper respiratory illnesses in the United States is dominated by viruses, including influenza A, B, respiratory syncytial virus, and SARS-CoV2. Mycoplasma pneumonia, treatable with antibiotics, can also cause upper respiratory symptoms and is typically associated with about 15 % of cases. There is no clinical or radiologic finding diagnostic of Mycoplasma pneumonia infection and PCR-based testing is not routinely used in the clinical setting. Further, the bacteria grows slowly in culture and the diagnostic IgM response will take days after the onset of infection. Thus, a rapid diagnostic test for Mycobacterium pneumonia infection is needed. This study documented two cases of Mycoplasma pneumonia infection of the upper respiratory system using in situ hybridization in a series of over 20 patients who were being tested for SARS-CoV2 infection. The respiratory secretions were placed on a glass slide, fixed in 10 % buffered formalin, and then tested using a Mycoplasma pneumonia probe. The high bacterial number associated with acute infection allowed for straightforward detection by in situ hybridization in a few hours. Antibiotic therapy led to rapid resolution of the symptoms. This highlights the ability of standard in situ hybridization as a rapid diagnostic test for Mycoplasma pneumonia in the clinical setting.

Mycoplasma pneumoniae COVID-19 Delta Variant Co-Infection Mimicking COVID-19 ARDS.

The Delta variant of COVID-19 has been associated with severe disease causing a surge in the second half of 2021. Atypical pathogens can be present in those in particular with severe ARDS and can contribute to excess morbidity and mortality. We must maintain a high level of suspicion for these pathogens as this can present an opportunity to dramatically improve the prognosis of a patient with COVID-19 ARDS. However, lend caution to Mycoplasma IgM serology as this can be a false-positive. If suspicion remains high for Mycoplasma pneumoniae infection, sputum polymerase chain reaction (PCR) for M pneumoniae is the gold standard for diagnosis. We present the case of a 42-year-old female with COVID-19 Delta variant presumed ARDS who had co-infection with M pneumoniae confirmed by endotracheal sputum aspirate PCR with rapidly improving oxygenation and extubation within 4 days of effective antibiotic therapy.

Case report: A pediatric case of Bickerstaff brainstem encephalitis after COVID-19 vaccination and Mycoplasma pneumoniae infection: Looking for the culprit.

Bickerstaff brainstem encephalitis (BBE) is a rare, immune-mediated disease characterized by the acute onset of external ophthalmoplegia, ataxia, and consciousness disturbance. It has a complex multifactorial etiology, and a preceding infectious illness is seen in the majority of cases. Immune-mediated neurological syndromes following COVID-19 vaccination have been increasingly described. Here we report the case of a child developing BBE 2 weeks after COVID-19 vaccination. Despite nerve conduction studies and CSF analysis showing normal results, BBE was diagnosed on clinical ground and immunotherapy was started early with a complete recovery. Later, diagnosis was confirmed by positive anti-GQ1b IgG in serum. Even if there was a close temporal relationship between disease onset and COVID-19 vaccination, our patient also had evidence of a recent Mycoplasma pneumoniae infection that is associated with BBE. Indeed, the similarity between bacterial glycolipids and human myelin glycolipids, including gangliosides, could lead to an aberrantly immune activation against self-antigens (i.e., molecular mimicry). We considered the recent Mycoplasma pneumoniae infection a more plausible explanation of the disease onset. Our case report suggests that suspect cases of side effects related to COVID-19 vaccines need a careful evaluation in order to rule out well-known associated factors before claiming for a causal relationship.

Pathogenic changes of community-acquired pneumonia in a children's hospital in Beijing, China before and after COVID-19 onset: a retrospective study.

BACKGROUND: This study aimed to analyze the pathogenic characteristics of community-acquired pneumonia (CAP) in a children's hospital before and after the coronavirus disease 2019 (COVID-19) pandemic and to provide testimony for preventing CAP in the future. METHODS: A retrospective analysis was performed. The information was collected from the electronic medical record system of the hospital. A total of 2739 children were included from February 1, 2019, to January 31, 2021. RESULTS: Among these 2739 patients were 1507 (55.02%) males and 1232 (44.98%) females; the median age was 3.84 years. There were 2364 cases during the pre-COVID-19 period and 375 cases during the post-COVID-19 period. The number of hospitalized children after the pandemic was 84.14% lower. The median age after the onset was 1.5 years younger than that before the onset (4.08 years old) (Z = - 7.885, P < 0.001). After the pandemic, the proportion of CAP in school-age children and Mycoplasma pneumoniae pneumonia (MPP) and influenza virus pneumonia (IVP) decreased significantly. During the pre-COVID-19 period, the proportions of detected pathogens were as follows: MP (59.56%) > bacteria (50.42%) > viruses (29.57%) > fungi (3.43%). During the post-COVID-19 period, the pathogen proportions were bacteria (56.53%) > viruses (53.60%) > MP (23.47%) > fungi (3.73%). CONCLUSIONS: There was a significant decrease in the number of children with CAP hospitalized after the pandemic, especially among school-age children, and the pathogen proportions of CAP with MP and IV were significantly decreased. We inferred that CAP was effectively prevented in school-age children because of the strong mitigation measures.

Viruses and Mycoplasma pneumoniae are the main etiological agents of community-acquired pneumonia in hospitalized pediatric patients in Spain.

OBJECTIVES: To describe the etiology of community-acquired pneumonia (CAP) in hospitalized children in Spain and analyze the predictors of the etiology. HYPOTHESIS: The different etiological groups of pediatric CAP are associated with different clinical, radiographic, and analytical data. DESIGN: Observational, multicenter, and prospective study. PATIENT SELECTION: This study included children aged 1 month to 17 years with CAP, who were hospitalized between April 2012 and May 2019. METHODS: An extensive microbiological workup was performed. The clinical, radiographic, and analytical parameters were analyzed for three etiological groups. RESULTS: Among the 495 children included, at least one causative pathogen was identified in 262 (52.9%): pathogenic viruses in 155/262 (59.2%); atypical bacteria (AB), mainly Mycoplasma pneumonia, in 84/262 (32.1%); and typical bacteria (TyB) in 40/262 (15.3%). Consolidation was observed in 89/138 (64.5%) patients with viral CAP, 74/84 (88.1%) with CAP caused by AB, and 40/40 (100%) with CAP caused by TyB. Para-pneumonic pleural effusion (PPE) was observed in 112/495 (22.6%) patients, of which 61/112 (54.5%) presented a likely causative pathogen: viruses in 12/61 (19.7%); AB in 23/61 (37.7%); and TyB in 26/61 (42.6%). Viral etiology was significantly frequent in young patients and in those with low oxygen saturation, wheezing, no consolidation, and high lymphocyte counts. CAP patients with AB as the etiological agent had a significantly longer and less serious course as compared to those with other causative pathogens. CONCLUSIONS: Viruses and M. pneumoniae are the main causes of pediatric CAP in Spain. Wheezing, young age, and no consolidation on radiographs are indicative of viral etiology. Viruses and AB can also cause PPE. Since only a few cases can be directly attributed to TyB, the indications for antibiotics must be carefully considered in each patient.

Atypical pneumonia caused by Chlamydia psittaci during the COVID-19 pandemic.

OBJECTIVES: Here, we retrospectively described the diagnosis and treatment of 32 cases diagnosed with Chlamydia psittaci pneumonia during the COVID-19 pandemic. METHODS: Clinical information was collected from all the patients. Reverse transcription-PCR and ELISAs were conducted for the detection of COVID-19 using nasal swabs and bronchoalveolar lavage fluid (BALF) samples. Metagenomic next-generation sequencing (mNGS) was performed for the identification of causative pathogens using BALF, peripheral blood and sputum samples. End-point PCR was performed to confirm the mNGS results. RESULTS: All 32 patients showed atypical pneumonia and had infection-like symptoms that were similar to COVID-19. Results of reverse transcription-PCR and ELISAs ruled out COVID-19 infection. mNGS identified C. psittaci as the suspected pathogen in these patients within 48 hours, which was validated by PCR, except for three blood samples. The sequence reads that covered fragments of C. psittaci genome were detected more often in BALF than in sputum or blood samples. All patients received doxycycline-based treatment regimens and showed favorable outcomes. CONCLUSION: This retrospective study, with the highest number of C. psittaci pneumonia enrolled cases in China so far, suggests that human psittacosis may be underdiagnosed and misdiagnosed clinically, especially in the midst of the COVID-19 pandemic.

The Triad of Legionnaires' Disease, Rhabdomyolysis, and Acute Kidney Injury: A Case Report.

BACKGROUND Legionella infection is a common cause of atypical pneumonia, known as Legionnaires' disease when infection extends to extrapulmonary involvement, which often leads to hospitalization. The triad of Legionella pneumonia, rhabdomyolysis, and renal failure displays a rare yet fatal complication without prompt management. CASE REPORT Our patient was a 62-year-old man with no significant medical history who developed Legionnaires' disease with severely elevated creatinine phosphokinase (CPK) of 9614 mcg/L, consistent with rhabdomyolysis. He experienced severe headache, anorexia, and hematuria, which prompted him to seek medical care. Pertinent social history included recent flooding in his neighborhood, which surrounded the outer perimeter of his home. His clinical manifestations and laboratory findings were consistent with Legionella infection, with concomitant acute kidney injury. A chest X-ray revealed hazy left perihilar opacities concerning for atypical pneumonia. Immediate interventions of hydration and antigen-directed azithromycin were initiated to prevent rapid decompensation. His clinical symptoms resolved without further complications, and he was not transferred to the Intensive Care Unit (ICU). CONCLUSIONS Legionella-induced rhabdomyolysis is an uncommon association that can lead to acute kidney failure and rapid clinical deterioration. Early and aggressive management with fluid repletion and appropriate antibiotics can improve clinical manifestations and hospital length of stay. Our patient's reduction in CPK levels and clinical improvement confirmed that extrapulmonary involvement in Legionella infection can lead to rhabdomyolysis. It is important for healthcare providers to recognize the clinical triad of Legionella pneumonia, rhabdomyolysis, and renal failure as prompt and timely management to reduce associated morbidity.