Severity of Disease, Radiographic Presentation, and Outcomes in Ten Adult Patients with Mycoplasma pneumoniae Pneumonia: Results from the Rapid Empiric Treatment with Oseltamivir Study (RETOS)

Cynthia Meza¹, Fabiola Gianella¹, Sriram Maranganti¹, Amy Holloway¹, Raul Nakamatsu¹ ²׳ 1. Division of Infectious Diseases, University of Louisville, 2. Division of Infectious Diseases, Robley Rex VA Medical Center

ABSTRACT  Background: Mycoplasma pneumoniae a common cause of atypical pneumonia. Mycoplasma infection can occur at any age, but infection rates are highest among school aged children, military recruits, and college students. M. pneumoniae is considered a mild form of community-acquired pneumonia(CAP). There is little literature describing the characteristics of the adult population with pneumonia due to M. pneumoniae. The objective of the study was to describe the severity of disease, radiographic findings and outcomes in adult hospitalized patients with CAP due to M. pneumoniae.

Methods: This was a secondary analysis of the RETOS database, an ongoing, randomized, prospective clinical trial to evaluate the impact of rapid empiric treatment with oseltamivir on the outcomes of hospitalized patients with lower respiratory tract infections (LRTIs). All patients admitted to eight hospitals in Louisville, Kentucky from December 2010 to March 2012 with a diagnosis of LRTI were invited to participate in the study. Patients with diagnosis of CAP and a PCR positive for M. pneumoniae were included.

Results: A total of 10 hospitalized adult patients with CAP due to M. pneumoniae were analyzed. The average age was 46, and 9 (90%) were male. One patient (10 %) was admitted to the ICU. Based on the pneumonia severity index risk class, 2 patients were risk class I, 4 patients were risk class II, 2 patients were risk class III, and two patients were risk class IV. Radiographic findings included: the presence of parenchymal opacification (n=4, 40%), interstitial infiltrate (n=3, 30%), reticulonodular infiltrate (n=2, 20%) and nodular opacity (n=1, 10%). Seven patients (70%) had multilobar infiltrates. Clinical outcomes included: time to clinical stability, 4±2 days; length of stay, 6±2 days; mortality (0, 0%).

Conclusions: The data from our study indicate that CAP due to by M. pneumoniae in adult patients can lead both mild and severe presentation. There are no typical radiographic manifestations in patients with CAP due to M. pneumoniae. With appropriate empiric therapy, good patient outcomes can be expected.

INTRODUCTION

REFERENCES

RESULTS (Cont’d)

 

  

Our study indicates that CAP due to Mycoplasma pneumoniae in adult patients can lead both mild and severe presentation.

There are not typical radiographic manifestations in patients with Cap due to Mycoplasma pneumoniae

Very few studies describing the characteristics of the adult population with pneumonia due to Mycoplasma pneumoniae

With appropriate empiric therapy at the right time, good patient outcomes can be expected.

CONCLUSIONS

Figure 1. Radiographic findings of patyeints with Mycoplasma pneumoniae

Table 2: Frequency of lobe involvement.

 

. Study design and Study population This was a secondary analysis of RETOS database, an ongoing, randomized, prospective clinical trial to evaluate the impact of rapid empiric treatment with Oseltamivir on the outcomes of hospitalized patients with LRTIs, in 4 hospitals in Louisville, Kentucky, during 2010/2012 influenza season.

Patients signed consent for enrollment in the study and answered a questionnaire regarding the duration of signs and symptoms of the disease with. The study was approved by the Ethics Committee of each hospital.

Study definitionsCAP was defined as the presence of a new pulmonary infiltrate on a chest radiograph at the time of hospitalization that was associated with at least one of the following:• New or increased cough • An abnormal temperature (<35.6˚C or > 37˚C)• Leukocytosis (leukocyte count > 10,500 cells/µL),leucopenia

(leukocyte count < 4,500 cells/µL), or left shift (>5% immature neutrophils)

• RT- PCR (+) for Mycoplasma pneumoniae

Patients were classified into five PSI risk classes according to the scoring system based on the risk factors as shown below: Table 1 : PSI Risk class Score

I 0

II < 70

III 71 – 90

IV 91 – 130

V > 130

1. Cough and Shortness of breath (Normal or improving)2. Afebrile for atleast 8 hours (<38 ˚C or <100 F)3. WBC improving (1>10%)4. Intake and absorption adequate

.

.

RESULTS

• Community Acquired Pneumonia is a common and serious infectious disease associated with high morbidity and mortality rates. (1) Mycoplasma Pneumoniae is considered a mild form of Community acquired pneumonia (CAP). Mycoplasma pneumoniae is responsible for more than 20 % of Community Acquired Pneumonia cases, and capable of causing upper respiratory illness as well. (2)

• There are several published pneumonia scores to assess for severity of disease at the time of hospitalization and predict clinical outcomes in patients with CAP [3].

• Time to clinical stability (TCS) is an important early outcome in hospitalized patients with CAP.

• The objective of the study was to describe the severity of disease, radiographic findings and outcomes in adult hospitalized patients with Community acquired Pneumonia due to Mycoplasma pneumoniae.

MATERIALS AND METHODS

Time to clinical stability criteria was defined as the day that the following four criteria were met

Statistical AnalysisFor patients with Mycoplasma pneumoniae, frequencies and percentages were used to describe categorical variables and means were used to describe continuous variables.

A total of 10 hospitalized patients with CAP due to Mycoplasma pneumoniae were analyzed.

The average age was 46 and 90% were male. One patient was admitted to the ICU. The table 1 shows the clinical characteristics of Pneumonia patients on admission to hospital.

1. Fahmi S, Bibiana C, Orna N, et al. Etiology of Community-Acquired Pneumonia in Hospitalized Patients in Northern Israel. IMAJ • VOL 12 • August 2010

2. Mony S, Moshe R-A, Uzi I, et. al.Massive empyema caused by Mycoplasma pneumoniae in an adult: A case report. BMC Infectious Diseases 2006, 6:18 doi:10.1186/1471-2334-6-18. 3. Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007; 44(suppl):S27-S724. Naoyuki M, Tadaaki S, Yasuhiro K, et al. Radiographic features of Mycoplasma pneumoniae pneumonia: differential diagnosis and performance timing. BMC Medical Imaging 2009, 9:7 doi:10.1186/1471-2342/9/75. Stephen G. Mycoplasma pneumoniae infection in adults. www.uptodate.com

Table 1: Clinical characteristics of CAP patients in the study

Age 46 Male gender 9 (90%)

PSI Risk ClassesI 2

II 4

III 2

IV 2

V 0

Study sampleNasopharyngeal (NP) and oropharyngeal (OP) swabs were collected at the time of study entry. OP swabs were used for detection of Legionella pneumophila, Chlamydophila pneumonia and Mycoplasma pneumoniae.RT-PCR was used for detection.

Radiographic findings (fig 1) included: the presence of parenchymal opacification (n=4, 40%), interstitial infiltrate (n=3,30%),reticulonodular infiltrate (n=2,20%) and nodular opacity (n=1,10%). Seven patients have multilobar infiltrate (table 2). Patients were treated empirically with macrolide.

Clinical outcomes included: time to clinical stability, 4±2 days; length of stay, 6±2 days; mortality (0,0%).

RUL RML RLL LAL LLL

1       

 2        

 3        

 4        

 5        

 6        

 7        

 8        

 9        

 10