Native vertebral osteomyelitis due to community acquired MRSA

Summary

70 year old previously healthy man from Yangon admitted to Tropical and Infectious Diseases Department of Yangon General Hospital on 30th July 2018 with high fever with chills and rigors, cough with sputum for 1week and low back pain for 3 days. During hospitalization, he suddenly developed bilateral lower limbs weakness with sphincter involvement. Examination revealed SPO2 90% on air with coarse crepitation on right lower zone. Normal vital signs with spastic paraplegia (motor power 2/5) with sensory level L1. Investigations showed neutrophil leukocytosis with very high CRP 463 mg/L. Both blood and sputum culture reported as methicillin resistant Staphylococcus aureus(MRSA). Sputum Gene Xpert turned out to be negative. CXR (PA) was chest infection right lower zone with minimal pleural effusion.Spine X rayshowed OA change with compressed fracture L1 and L2. MRI thoracic spine explored osteomyelitis at body of T8 and posterior element of T9 with para-vertebral and para-spinous cellulitis causing mild cord compression,cord oedema and posterior facet arthritis at T9-T10 and T10-T11.

IV Cefoperazone with sulbactum was given initially as for pneumonia and then changed to IV vancomycin based on sensitivity results. After 3 week of antibiotic, motor power was improved up to 4/5 and CRP was decreasedto 4.4mg/l. He was discharged after 1 month of hospitalization and planned to give IV vancomycin for total 6 weeks and plan to recheck inflammatory markers on 4 weeks of antibiotic.

Background

Paraplegia is caused mainly by disorders of the spinal cordand the cauda equine. Among non-traumatic casues of paraplegia,infection is one of the most important causes. Several infections may cause paraplegia. They are classified into two categories: those thatinvolve the spinal cord directly and those that involve vertebral column and cause pressureeffect on the spinal cord that eventually leads to paraplegia [1].Osteomyelitis is infection of bone most commonly due to bacterial infection. When patient presents with fever, back pain and painful restriction of movement with or without neurological involvement should be aware of osteomyelitis by attending physician.Indeed, it should be kept in mind that theabsence of fever does not rule out osteomyelitis and the classic triad of fever, pain and increasedmarkers of inflammation is not always present [2].Treatment of osteomyelitisinfections is challenging due a variety of factors, including the poor bioavailability ofantibiotics in bone tissue, rising antibiotic resistance in bacterial pathogens, and the biofilmlikeproperties of the infection [3]. In adults, the most common site is the vertebral bodies, followed by long bones, pelvis, andclavicle[4]. Staphylococcus aureus isa prominent bacterial pathogen and the most frequent isolated causal agent of infection that inducedosteomyelitis [5].Infections with methicillin resistant Staphylococcusaureus (MRSA) have occurred since the 1960s, but weremainly limited to hospital and health care settings. Sporadicreports of community acquired MRSA (CAMRSA) infectionsoccurred between 1980 and 1999. There has been an increasein the number of reported community acquired casessince 1999 [6]. According to study done in Myanmar during 2007-2008, MRSA has been detected in community [7]. The clinical spectrum of infections caused by community acquired MRSA has been wideranging from minor skin and soft tissue infections to life threateningpneumonias, septicemias, osteomyelitis and bacterial endocarditic [8].There is alsoincrease in incidence and severityof acute hematogenous osteomyelitis and septicarthritis has been observed, especially in cases concerningMRSA[9].The incidence and severity of methicillin resistant Staphylococcus aureus (MRSA) infections are increasing and cause high mortality and morbidity.Early detection is crucialgiven that a delay in the diagnosis of only 4 days is a risk factor for long-term sequel [10]. Due to these challenges, osteomyelitis is still devastating for manypatients with painful long-term consequences.

Case presentation

Previously healthy70 year old man from Yangon was admitted to Tropical and Infecious Diseases Department of Yangon General Hospital on 30th July 2018 with chief complaint of high fever with chill and rigor and productive cough for 1week duration. No history of haemoptysis or chest pain. He also complained of low back pain for 3 days without preceding history of trauma. Pain was more severe on movement. On day 3 of admission, he suddenly developed bilateral lower limbs weakness with sphincter involvement. No associated with fits or impaired consciousness.

Medical history

He has no history of hypertension or diabetes. Denied history of tuberculosis.

Surgery history

No history of spine injury or surgery.

Physical examination

Examination revealed slight dyspnoea with SPO2 90% on air with coarse crepitation on right lower zone. On neurological examination revealed spastic paraplegia of motor power 2/5 with sensory level L1 with urinary catheter in situ. Normal vital signs. No papilledema on fundoscopic examination.

Investigations

Investigations showed total WBC was 18 10^9/L with very high CRP 463 mg/L. Normal liver and renal function. Blood and sputum culture were done before antibiotics and reported as methicillin resistant Staphylococcus aureus (MRSA). CXR(PA) revealed chest infection right lower zone with minimal pleural effusion. USG (abd) was normal and spine X ray reported OA change with compressed fracture L1 and L2. MRI thoracic spine explored osteomyelitis at body of T8 and posterior element of T9 with para-vertebral and para-spinous cellulitis causing mild cord compression and cord oedema and posterior facet arthritis at T9-T10 and T10-T11.

Treatment

IV Cefoperazone with sulbactum was given initially as empirical therapy for pneumonia and then changed to IV vancomycin according to sensitivity. IV dexamethazone was given short course for spinal cord compression.

Outcome and follow up

After 3 weeks of antibiotic, motor power was improved up to 4/5 and CRP was decreased to 4.4mg/l. He was discharged on 1 month of hospitalization and he was planned to give IV vancomycin for total 6 weeks and plan to recheck inflammatory markers on 4 weeks of antibiotic.

Discussion

Although first identified just >4 decades ago, methicillin-resistant Staphylococcus aureus (MRSA) has undergonerapid evolutionary changes and epidemiologic expansion to become a major cause of nosocomial and community-acquired infections worldwide[10]. Methicillin-resistantS.aureus (MRSA) is usually considered a nosocomial pathogen, but increasingly it is acquired in the community [11]. Community acquired MRSA can cause severe diseases, such as necrotizing pneumonia, osteomyelitis, and septicemia. Most community acquired MRSA infections resolve, but deaths from invasive disease have been reported[12]. The changing epidemiology of MRSA became evident when MRSA infections occurred in previously healthy patients without established risk factors for MRSA acquisition [13]. Case report from Turkey stated that 17 year old man without risk factors present with MRSA osteomyelitis proved by bone needle aspirate and bone culture. He recovered completely at 6 months by 2week treatment of IV teicoplanin followed by PO TMP/SMX for 4 weeks[11].Also 13 year old healthy boy from Scandinavia presented with severe MRSA infection encompassing pneumonia, septic arthritis, and osteomyelitis.That case had favorable outcome with close interdisciplinary treatment with frequent surgical interventions andantimicrobial combination therapy[14]. Moreover, another case report was from Australia stated that a 16 years old man presented with left humerus MRSA osteomyelitis who responded well to PO rifampacin and fusidic acid for 6 weeks [8].A retrospective study from Cleveland clinic from Ohio included 255 patients of vertebral osteomyelitis and reported that most common sited was lumbar followed by thoracic vertebral and most common causal organism was staphylococcus aureus[15].

Take home message

Most of the case reports are due to community acquired MRSA like our case without risk factors like our case. Therefore, MRSA becomes prevalent in community these days. Moreover,osteomyelitis due to MRSA is usually more aggressive, with higher inflammation markers,prolonged hospital stays and increased possibility to undergo surgical treatment[16]. Plain radiographs are normal in the early period of infection. Therefore, MRI is the study of choice and it is the most sensitive and specific imaging technique for the diagnosis of a spinal infection[17].In the presence of more serious and invasive infections, immediatetherapy with vancomycin or linezolid should be instituted withoutdelay until treatment can be modified by culture results [9]. Therefore, clinicians should be aware of this emerging community acquired MRSA infection in treating patients with osteomyelitis because timely treatment and intervention can lead to favourable outcomes.

Reference

1. Abbasi F, Fardkhani SK. Paraplegia Caused by Infectious Agents;Etiology, Diagnosis and Management. InTopics in Paraplegia 2014. InTech.
2. Dartnell J, Ramachandran M, Katchburian M. Haematogenous acute and subacute paediatric osteomyelitis: a systematic review of the literature. The Journal of bone and joint surgery. British volume. 2012 May;94(5):584-95.
3. Zimmerli W, Trampuz A, Ochsner PE. Prosthetic-joint infections. New England Journal of Medicine. 2004 Oct 14;351(16):1645-54.
4. Calhoun, J.H. and Manring, M.M., 2005. Adultosteomyelitis. Infectious Disease Clinics, 19(4), pp.765-786.
5. Hatzenbuehler J, Pulling TJ. Diagnosis and management of osteomyelitis. American family physician. 2011 Nov 1;84(9):1027.
6. Dailey L, Coombs GW, O’Brien FG, Pearman JW, Christiansen K, Grubb WB, Riley TV. Methicillin-resistant Staphylococcus aureus, western Australia. Emerging infectious diseases. 2005 Oct;11 (10):1584.
7. Aung MS, Urushibara N, Kawaguchiya M, Aung TS, Mya S, San T, Nwe KM, Kobayashi N. Virulence factors and genetic characteristics of methicillin-resistant and-susceptible Staphylococcus aureus isolates in Myanmar. Microbial Drug Resistance.2011Dec;17(4):525- 35.
8. Puthiyaveetil SA. Osteomyelitis: A case report. Australian family physician. 2009 Jul;38(7):521.
9. Arnold SR, Elias D, Buckingham SC, Thomas ED, Novais E, Arkader A, Howard C. Changing patterns of acute hematogenous osteomyelitis and septic arthritis: emergence of community-associated methicillin- resistant Staphylococcus aureus. Journal of Pediatric Orthopaedics. 2006 Nov 1;26(6):703-8.
10. Boucher H, Miller LG, Razonable RR. Serious infections caused by methicillin-resistant Staphylococcus aureus. Clinical Infectious Diseases. 2010 Sep 15;51(Supplement_2):S183-97.
11. Uluğ M, Ayaz C, Celen MK. A case report and literature review: osteomyelitis caused by community-associated methicillin resistant Staphylococcus aureus. The Journal of Infection in Developing Countries. 2011 Dec 5;5(12):896-900.
12. Buck JM, Como-Sabetti K, Harriman KH, Danila RN, Boxrud DJ, Glennen A, Lynfield R. Community-associated methicillin-resistant Staphylococcus aureus, Minnesota, 2000–2003. Emerging infectious diseases. 2005 Oct;11(10):1532.
13. Chambers HF. The changing epidemiology of Staphylococcus aureus?. Emerging infectious diseases. 2001 Mar;7(2):178.
14. Hardgrib N, Wang M, Jurik AG, Petersen KK. Life-threatening MRSA sepsis with bilateral pneumonia, osteomyelitis, and septic arthritis of the knee in a previously healthy 13-year-old boy: a case report. Acta radiologica open. 2016 Oct;5(10):2058460116677180.
15. McHenry MC, Easley KA, Locker GA. Vertebral osteomyelitis: long- term outcome for 253 patients from 7 Cleveland-area hospitals. Clinical Infectious Diseases. 2002 May 15;34(10):1342-50.
16. Chiappini, E., Mastrangelo, G. and Lazzeri, S., 2016. A case of acute osteomyelitis: an update on diagnosis and treatment.International journal of environmental research and public health, 13(6), p.539.
17. Malawski SK, Lukawski S. Pyogenic infection of the spine. Clinical orthopaedics and related research. 1991 Nov(272):58-66.

Figure 1 MRI ( thoracic spine): osteomyelitis at body of T8 and posterior element of T9 with para-vertebral and para-spinous cellulitis causing mild cord compression and cord oedema and posterior facet arthritis at T9-T10 and T10-T11.