Septic Arthritis caused by Group A Streptococcus in Newborn: An Unusual Presentation

Streptococcal sepsis in neonates is a potentially lethal condition. A wide spectrum of clinical presentations has been often reported in Group B Streptococcal infections in neonates. Bone and joint infections which are caused by Group B Streptococcus are also encountered frequently, but they have not yet been reported in case of Group A Streptococcal infection in neonates. Here, we are reporting a case of septic arthritis and late onset neonatal sepsis which were caused by Group A Streptococcus in a full term, healthy baby.

Neonatal sepsis is a clinical syndrome of blood stream infections, with systemic signs of sepsis occurring in the first month of life. As compared to the pre-antibiotic era, the frequency of the neonatal sepsis which is caused by Group A Streptococcus (GAS) has decreased drastically and its complications are also showing a decreasing trend. The mortality which is caused by the GAS infection in neonates is uncommon nowadays. However, Group B Streptococcus (GBS) has emerged as a prominent aetiology in neonatal infections [1]. Although bone and joint infections in newborns are not an infrequent observation in the GBS infection, they are a rarity in case of GAS. Septic arthritis which is caused by GAS, is mainly reported in adults rather than in neonates. As per a recent prospective surveillance study, the estimate of Group A streptococcal septic arthritis was 7.4% in the Indian population [2]. Negative blood cultures in neonatal septic arthritis are reported in 40% of the cases, followed by 33% and 20% cases, which are attributed to gram negative bacteria viz., Klebsiella pneumoniae, Escherichia coli and Enterobacter and gram positive pathogens viz., Staphylococcus aureus, GBS and Streptococcus pneumonia in India respectively [3]. Here, we are reporting the clinical history of an unusual case of septic arthritis and late onset neonatal sepsis which was caused by GAS.

A 26 years old, second gravida lady delivered a 3.2 kg term healthy male baby by caesarean section. The baby had a breech presentation and meconium stained liquor and shortly after delivery, he developed jaundice, which responded well to phototherapy. On the 8th day of his life, his mother complained of a swelling on his right elbow and reduced movements of the right forearm. On examination, the diffuse swelling over the right elbow was found to be tender, along with signs of inflammation. Although there was no history which was suggestive of a pulled elbow injury, it was initially diagnosed as a dislocation of the elbow. It was not associated with the typical signs of sepsis like thermal instability, haemodynamic instability, bradycardia, and respiratory discomfort [4] and the haematological parameters were also within normal limits. However, the CRP value was high (3.6 mg/dl).

Ultrasonography revealed fluid accumulation in the affected elbow joint, which on aspiration was found to be serosanguinous and on direct microscopic examination, displayed few gram positive cocci in pairs and chains, amongst plenty of neutrophils. Both the blood culture and the pus aspirate from the elbow joint displayed the same strain of beta haemolytic streptococci which showed the same antibiotic sensitivity pattern. The isolate was identified as Streptococcus pyogenes by conventional method and it was further confirmed by serogrouping with the use of the Streptex Streptococcal grouping kit (Oxoid, United Kingdom, Lot Number 1083582, manufacturing date Feb, 2012). The signs of inflammation subsided after 2 days of parenteral ampicillin, cloxacillin and amikacin therapy. However, the swelling persisted. Incision and drainage of the pus and a second blood culture which was done on the 10th postnatal day, were found to be sterile. The postoperative period was uneventful and the wound was healthy. Oral ampicillin and erythromycin was started and baby was discharged on the 19th postnatal day.

Neonatal sepsis is a dreadful complication which contributes up to 12% of the total neonatal deaths in the Indian population [5]. Streptococcus pyogenes is a major cause of both puerperal as well as neonatal sepsis, especially in the developing countries. As per the WHO report, it was the cause of the bacteraemia in neonates in 0.55 per 1,000 live births [1]. GAS has also been reported to constitute about 21% of the cases of late onset neonatal sepsis in the Indian subcontinent [6]. However, over the past few decades, it has been replaced by GBS, which has emerged as a more successful pathogen, as a result of the asymptomatic colonization of the birth canal in pregnant women, which can be seen in as high as 35% women [7]. The Streptococcal sepsis in neonates occurs in two setups. The early onset sepsis manifests within the first week of life and the infection is acquired during the antenatal period through an ascending infection or intranatally from an exposure to the vaginal flora, while in late onset sepsis, the infection is mainly transmitted from an external source, especially from caregivers [8]. In this case also, it was likely that the baby had acquired the GAS infection postnatally, as the high vaginal swab for the antenatal GBS screening of the mother was negative.

The neonatal colonization by GAS was reported to be 19% in one study [9]. Although, S. pyogenes has been reported to cause neonatal sepsis, meningitis, skin infections, the toxic shock syndrome and unusual presentations like parotitis, it has not yet been reported to cause septic arthritis in neonate [9–13]. It is predominantly the result of a haematogenous spread and seeding in the synovial membrane. Monoarthritis is typical. However, multifocal GAS polyarthritis has also been reported [14]. The importance of serogrouping and sensitivity testing is of particular interest in cases of pregnant women with penicillin allergy, since erythromycin and clindamycin resistances are frequently prevalent among the GBS strains [8]. In this case, the diagnosis was challenging, since the classical signs of sepsis were absent and consequently, it was initially considered as a case of elbow joint dislocation. In such cases, the laboratory parameters have vital roles in the diagnosis. A high CRP level was the initial parameter which suggested a probable infective aetiology. Streptococcal sepsis frequently causes severe sepsis in newborns, with high mortality, particularly in premature neonates [7]. As there was no prematurity in this case, a prompt diagnosis and an appropriate treatment resulted in an uneventful resolution of the sepsis and the arthritis.

The GAS sepsis in neonates is potentially lethal and it also carries the risk of an outbreak in nurseries due to hospital cross infections. However, it is amenable to treatment if it is diagnosed early. The clinical presentation may be unique and it may be confused with GBS. Sero-grouping and susceptibility testing should be done for all the isolates, for a proper selection of antibiotics, especially in penicillin allergic patients.

[1]. Carapetis JR, The current evidence for the burden of Group A Streptococcal diseases, WHO/FCH/CAH/05·07. Geneva: World Health Organization; 2004. Available from: http://whqlibdoc.who.int/hq/2005/WHO_FCH_CAH_05.07.pdf  [Google Scholar]

[2]. Haggar A, Nerlich A, Kumar R, Abraham VJ, Brahmadathan KN, Ray P, Clinical and microbiologic characteristics of invasive Streptococcus pyogenes infections in North and South India J Clin Microbiol 2012 50(5):1626-31.  [Google Scholar]

[3]. Deshpande SS, Taral N, Modi N, Singrakhia M, Changing epidemiology of neonatal septic arthritis J Orthop Surg. (Hong Kong) 2004 12(1):10-13.  [Google Scholar]

[4]. De Assis Meireles L, Vieira AA, Costa CR, Evaluation of the neonatal sepsis diagnosis: use of clinical and laboratory parameters as diagnosis factors Rev Esc Enferm USP 2011 45(1):33-39.  [Google Scholar]

[5]. Bassani DG, Kumar R, Awasthi S, Morris SK, Paul VK, Shet A, Causes of neonatal and child mortality in India: a nationally representative mortality survey Lancet 2010 376(9755):1853-60.  [Google Scholar]

[6]. Bhutta ZA, Naqvi SH, Muzaffar T, Farooqui BJ, Neonatal Sepsis in Pakistan: Presentation and Pathogens Acta Pædiatrica 1991 80(6-7):596-601.  [Google Scholar]

[7]. Winn W Jr, Allen S, Janda W, Koneman E, Procop G, Schreckenberger P, Woods G, The gram positive cocci part II: Streptococci, Enterococci and “Streptococcus like” bacteria, Chapter 12 In: Koneman’s Color Atlas and textbook of Diagnostic Microbiology 2005 5th edUSALippincott Williams and Wilkins Company:577-603.  [Google Scholar]

[8]. Shet A, Ferrieri P, Neonatal & maternal group B streptococcal infections: a comprehensive review Indian J Med Res 2004 120(3):141-50.  [Google Scholar]

[9]. Isenberg HD, Tucci V, Lipsitz P, Fadklam RR, Clinical laboratory and epidemiological investigations of a Streptococcus pyogenes cluster epidemic in a newborn nursery J Clin Microbiol 1984 19(3):366-70.  [Google Scholar]

[10]. Diaz AM, Neonatal toxic shock syndrome due to Streptococcus pyogenes: case report and literature review Rev Chilena Infectol 2007 24(6):493-96.  [Google Scholar]

[11]. Krebs VL, Chieffi LN, Jurfest ME, Ceccon R, Diniz EM, Feferbaum R, Neonatal Streptococcus pyogenes meningitis and sagittal sinus thrombosis: case report Arq Neuropsiquiatr 1998 56(4):829-32.  [Google Scholar]

[12]. Farinas Salto M, De la Huerga Lopez A, Menendez Hernando C, Lopez ES, Late neonatal sepsis caused by Streptococcus pyogenes Arch Argent Pediatr 2011 109(4):85-87.  [Google Scholar]

[13]. Herrera GAA, Osguthorpe RJ, Acute neonatal parotitis caused by streptococcus pyogenes: a case report Clin Pediatr 2010 49(5):499-501.  [Google Scholar]

[14]. Millar TM, McGrath P, McConnachie CC, Polyarticular septic arthritis following septic circumcision Rural and Remote Health. [Internet] 2007 7:1-5.Available from: http://www.rrh.org.au  [Google Scholar]