3.307—Presumptive service connection for chronic, tropical or prisoner-of-war related disease, or disease associated with exposure to certain herbicide agents; wartime and service on or after J
(a) General.
A chronic, tropical, prisoner of war related disease, or a disease associated with exposure to certain herbicide agents listed in § 3.309 will be considered to have been incurred in or aggravated by service under the circumstances outlined in this section even though there is no evidence of such disease during the period of service. No condition other than one listed in § 3.309(a) will be considered chronic.
(1) Service.
The veteran must have served 90 days or more during a war period or after December 31, 1946. The requirement of 90 days' service means active, continuous service within or extending into or beyond a war period, or which began before and extended beyond December 31, 1946, or began after that date. Any period of service is sufficient for the purpose of establishing the presumptive service connection of a specified disease under the conditions listed in § 3.309(c) and (e).
(2) Separation from service.
For the purpose of paragraph (a)(3) and (4) of this section the date of separation from wartime service will be the date of discharge or release during a war period, or if service continued after the war, the end of the war period. In claims based on service on or after January 1, 1947, the date of separation will be the date of discharge or release from the period of service on which the claim is based.
(3) Chronic disease.
The disease must have become manifest to a degree of 10 percent or more within 1 year (for Hansen's disease (leprosy) and tuberculosis, within 3 years; multiple sclerosis, within 7 years) from the date of separation from service as specified in paragraph (a)(2) of this section.
(4) Tropical disease.
The disease must have become manifest to a degree of 10 percent or more within 1 year from date of separation from service as specified in paragraph (a)(2) of this section, or at a time when standard accepted treatises indicate that the incubation period commenced during such service. The resultant disorders or diseases originating because of therapy administered in connection with a tropical disease or as a preventative may also be service connected.
(5) Diseases specific as to former prisoners of war.
The diseases listed in § 3.309(c) shall have become manifest to a degree of 10 percent or more at any time after discharge or release from active service.
(6) Diseases associated with exposure to certain herbicide agents.
(i)
For the purposes of this section, the term “herbicide agent” means a chemical in an herbicide used in support of the United States and allied military operations in the Republic of Vietnam during the period beginning on January 9, 1962, and ending on May 7, 1975, specifically: 2,4-D; 2,4,5-T and its contaminant TCDD; cacodylic acid; and picloram.
(ii)
The diseases listed at § 3.309(e) shall have become manifest to a degree of 10 percent or more at any time after service, except that chloracne or other acneform disease consistent with chloracne, porphyria cutanea tarda, and acute and subacute peripheral neuropathy shall have become manifest to a degree of 10 percent or more within a year after the last date on which the veteran was exposed to an herbicide agent during active military, naval, or air service.
(iii)
A veteran who, during active military, naval, or air service, served in the Republic of Vietnam during the period beginning on January 9, 1962, and ending on May 7, 1975, shall be presumed to have been exposed during such service to an herbicide agent, unless there is affirmative evidence to establish that the veteran was not exposed to any such agent during that service. The last date on which such a veteran shall be presumed to have been exposed to an herbicide agent shall be the last date on which he or she served in the Republic of Vietnam during the period beginning on January 9, 1962, and ending on May 7, 1975. “Service in the Republic of Vietnam” includes service in the waters offshore and service in other locations if the conditions of service involved duty or visitation in the Republic of Vietnam.
(iv)
A veteran who, during active military, naval, or air service, served between April 1, 1968, and August 31, 1971, in a unit that, as determined by the Department of Defense, operated in or near the Korean DMZ in an area in which herbicides are known to have been applied during that period, shall be presumed to have been exposed during such service to an herbicide agent, unless there is affirmative evidence to establish that the veteran was not exposed to any such agent during that service. See also 38 CFR 3.814(c)(2).
(b) Evidentiary basis.
The factual basis may be established by medical evidence, competent lay evidence or both. Medical evidence should set forth the physical findings and symptomatology elicited by examination within the applicable period. Lay evidence should describe the material and relevant facts as to the veteran's disability observed within such period, not merely conclusions based upon opinion. The chronicity and continuity factors outlined in § 3.303(b) will be considered. The diseases listed in § 3.309(a) will be accepted as chronic, even though diagnosed as acute because of insidious inception and chronic development, except: (1) Where they result from intercurrent causes, for example, cerebral hemorrhage due to injury, or active nephritis or acute endocarditis due to intercurrent infection (with or without identification of the pathogenic micro-organism); or (2) where a disease is the result of drug ingestion or a complication of some other condition not related to service. Thus, leukemia will be accepted as a chronic disease whether diagnosed as acute or chronic. Unless the clinical picture is clear otherwise, consideration will be given as to whether an acute condition is an exacerbation of a chronic disease.
(c) Prohibition of certain presumptions.
No presumptions may be invoked on the basis of advancement of the disease when first definitely diagnosed for the purpose of showing its existence to a degree of 10 percent within the applicable period. This will not be interpreted as requiring that the disease be diagnosed in the presumptive period, but only that there be then shown by acceptable medical or lay evidence characteristic manifestations of the disease to the required degree, followed without unreasonable time lapse by definite diagnosis. Symptomatology shown in the prescribed period may have no particular significance when first observed, but in the light of subsequent developments it may gain considerable significance. Cases in which a chronic condition is shown to exist within a short time following the applicable presumptive period, but without evidence of manifestations within the period, should be developed to determine whether there was symptomatology which in retrospect may be identified and evaluated as manifestation of the chronic disease to the required 10-percent degree.
(d) Rebuttal of service incurrence or aggravation.
(1)
Evidence which may be considered in rebuttal of service incurrence of a disease listed in § 3.309 will be any evidence of a nature usually accepted as competent to indicate the time of existence or inception of disease, and medical judgment will be exercised in making determinations relative to the effect of intercurrent injury or disease. The expression “affirmative evidence to the contrary” will not be taken to require a conclusive showing, but such showing as would, in sound medical reasoning and in the consideration of all evidence of record, support a conclusion that the disease was not incurred in service. As to tropical diseases the fact that the veteran had no service in a locality having a high incidence of the disease may be considered as evidence to rebut the presumption, as may residence during the period in question in a region where the particular disease is endemic. The known incubation periods of tropical diseases should be used as a factor in rebuttal of presumptive service connection as showing inception before or after service.
(2)
The presumption of aggravation provided in this section may be rebutted by affirmative evidence that the preexisting condition was not aggravated by service, which may include affirmative evidence that any increase in disability was due to an intercurrent disease or injury suffered after separation from service or evidence sufficient, under § 3.306 of this part, to show that the increase in disability was due to the natural progress of the preexisting condition.