Arthritis in the highlands of Papua New Guinea

Accepted for publication 9 September 1992 Abstract Acute polyarthritis is an important cause of morbidity in many tropical countries. Classification has often been difficult, with the term tropical polyarthritis used for those in whom a diagnosis could not be made. The implication thatthis is a distinct entity isprobablyincorrect, with likely causes being septic arthritis or post-infective reactive arthritis. This study aimed to determine the types of arthritis found in 43 patients (30 men) presenting consecutively to the Goroka Base Hospital in the Eastern Highlands of Papua New Guinea. Gonococcal arthritis was diagnosed in eight patients (six men) on the basis of isolation of Neisseria gonorrhoeae from the joint aspirate. In all cases the N gonorrhoeae was identified by the closed culture system on chocolate agar, but not always by routine plating. There were no specific clinical features that identified patients with a gonococcal septic arthritis. The remaining 34 patients had an undifferentiated oligoarthritis. The pattern of arthritis in men and women was of a lower limb pauciarticular arthritis with a predilection for the knee and ankle joints. A total of30% of male patientshad ahistory ofurethraldischarge and44%0ofall patients hadprecedingdiarrhoea. Arthritis was the only feature in 590/o of patients and in 32% there was an associated enthesitis. In this study most patients had an oligoarthritis consistent with a reactive arthritis or a septic arthritis due to N gonorrhoeae. Broth inoculation of synovial fluid was the best method to isolateNgonorrhoeae, with standard methods for gonococcal isolation failing in some patients. It is recommended that the term 'tropical polyarthritis' is no longer used as it does not refer to a specific entity but consists of several known arthritides.