Lawrence A. Klapow, Ph.D.
Bioscience, 2841 Creekside Road, Santa Rosa, CA 95405 USA
Objective: 1) Describe the roundworm and how to find it.2) Determine its occurrence in CFS and controls in blinded diagnostic trials.
Methods: Coded three-day sputum collections from 30 CFS-CDC defined patients and 21 controls were examined. Identification required screening of numerous candidate specimens, clearing in glycerin, 1200X magnification using two polarizers,(one in the light source the other over the ocular lens), via a 12X video camera mounted to a straight tube microscope. Examination of photo-micrographs of both sides of the specimens, at multiple focal-depths, was needed for reliable identification. Males (200 to 350 microns long) where identified primarily by the structures of their reproductive system (genitals, spicules, and bursa). Females (550 to 950 microns long) where identified mainly by their mouth parts (trichostrongylid type bulbless esophagus; nerve ring; six unevenly sized prehensile lips; single amphid tubule; and a unique structure reported in a group of Austro-Asian roundworms, the cervical flange).
Results: Decayed specimens of C. pulmoni were found in 14 out of 30 (47 %) CFS patients, but not in 21 controls (chi-squared association, P<0.001). An additional two samples, one patient and one control, called positive by direct examination could not be confirmed by photo-micrographs (if included, P=0.003). The infection rate, adjusted for test sensitivity, is 63 percent (95% CL= 43% to 80%). Two positive patients, re-tested two years later, were both still positive. Late larval stages were also found.
Conclusion: A suspected new roundworm species, Cryptostrongylus pulmoni, infects a large percentage of CFS patients, estimated at 63% in the current study, but not controls. It is significantly associated with the syndrome, and has chronic properties. Microscopic identification of C. pulmoni is difficult and time consuming (~50 hours per specimen) due its extreme rarity, small size, and the decayed state of specimens in naturally expelled sputum.
Source: www.ahmf.org. Presented at the 2001 Clinical and Scientific Meeting: Myalgic Encephalopathy/Chronic Fatigue Syndrome: "The Medical Practitioners' Challenge in 2001."