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The first isolation of bussuquara virus from man
CORRESPONDENCE
541
A VIRUS DISEASEOF THE MALARIAPARASITE S t R , - - I n 1968 I wrote to you about my hypothesis regarding the existence of a virus disease of the malaria parasite, and you were kind enough to publish my letter in Vol. 62 of the same year. It is of interest to note that the same hypothesis has now been proved correct, as reported by DAVIES and HOWELLS (1971) and by TERZAKIS (1969). As I suggested earlier (1968), this virus disease is a natural agent for the destruction of malaria parasites, and an intensive study of the problem may provide a means of biological control of the malaria parasite. It will be recalled that I demonstrated and described (1958, 1959) Feulgen-positive inclusion bodies in the degenerating o6cysts of Plasmodium cynomolgi bastianellii, and also in Plasmodium gallinaceum. O6cysts harbouring such inclusion bodies suffered loss of nuclei and dead o6cysts exhibited a black pigment mass. It would appear that the so-called Ross's black spores may represent o6cysts killed by the virus. Further investigation may ctarit~" this point. I am, etc., B. DASGUPTA, D e p a r t m e n t of Zoology, G o v e r n m e n t College, Darjeeling, 8 June, 1971 India. REFERENCES
DASGUPTA,B. (1958). Trans. R. Soc. trop. Med. Hyg., 52, 9. - (1959). Quart. J. micr. Sci., 100, 241. - (1968). Trans. R. Soc. trop. Med. Hyg., 62, 730. DAVIES, E. E. & HOWELLS, R. E. (1971). Trans. R. Soc. trop. Med. Hyg., 65, 13. TERZAKIS,J. A. (1969). Milit. Med., 134, 10 (suppl.), 916.
THE FIRST ISOLATION OF BUSSUQUARAVIRUSFROM MAN S I R , - - T h e prototype strain of Bussuquara (BSQ), a group B arbovirus, was isolated from a sentinel monkey in Brazil in 1956 (GOMES and CAUSEY, 1959). T h i s virus was shown to be widespread among Proechimys rodents in the same area (SHOPE, 1963). However, no isolations have been reported from h u m a n subjects. Strains closely related to the B S Q virus were repeatedly isolated from different regions in Panama since 1959 from sentinel animals, mosquitoes and rodents (GALINDO et al., 1966; and SRIHONGSEet al., unpublished). T h e present communication reports a natural infection of B S Q virus in a febrile h u m a n resident of Arenosa, a village approximately 30 miles northwest of Panama City, in October 1964. T h e patient, an adult male 29 years old, was ill for 4 days with fever, anorexia, restlessness and joint pain without evidence of inflammation, He complained of chills, profuse sweating and continuous frontal headache. Physical examination revealed only dental caries and a functional systolic m u r m u r , in addition to the low-grade fever. N o other abnormal signs and symptoms were found. A virus was isolated by inoculation of suckling mice with blood serum obtained on the first day of illness. T h e isolated virus was studied by standard serological techniques (haemagglutination-inhibition, complement-fixation and neutralization) and was found to be closely related, if not identical, to the Be An 4116 strain of B S Q virus isolated from Brazil. T h e patient m o v e d out of the village during the convalescent period and we were unable to locate him until about a year later. Results of serological tests performed at that time showed a significant increase in antibody titre both to Bussuquara virus and, to a lesser extent, certain other group B arboviruses. T o determine the prevalence of B S Q virus infection in man, serum surveys of some 1,715 people living in Arenosa and adjacent villages close to the G a t u n Lake region of Central Panama were made. 34% of these individuals exhibited H I antibodies to group B arboviruses, which is a highly cross-reactive group of viruses. At least 20% of these positives showed relatively higher titres to B S Q than to 3 other antigens (Yellow fever, St. Louis encephalitis and Ilheus) included in the tests. F u r t h e r m o r e , neutralization tests were performed with some
542
CORRESPONDENCE
of the BSQ HI-positive sera. From a total of 383 samples tested, 46% were positive. Therefore, it seems very likely that a number of these people have been infected with BSQ virus. Although the BSQ virus isolated from this patient represents the only reported laboratory documented human case, the results of our serological surveys indicate that infection with this virus is probably widespread among the human populations in certain areas in the Republic of Panama. If we consider these findings together with those incriminating Proechimys and Sigmodon rodents as reservoir hosts as well as culicine mosquitoes as potential vectors of BSQ virus in Panama, then we may speculate that BSQ is a medically important virus which could create health hazards to non-immune populations migrating to the endemic areas. We are, etc., NUNTHORN SRIHONGSE, CARL M. JOHNSON, Gorgas Memorial Laboratory, lOJune, 1971 Panama, Republic of Panama.
REFERENCES GALINDO, P., SRIHONGSE,S., RODANICHE,E. DE & GRAYSON,M. A. (1966). Am. J. trop. Med. Hyg., 15, 385. GOMES, G. & CALTSEY,O. R. (1965). Proc. Soc. exp. Biol. Med., 101,275. SHOPE,R. E. (1963). Ann. Microbiol., 11, 167. SRIHONGSE, S., GALINDO,P. & JOHNSON, C. M. (Unpublished).
541
A VIRUS DISEASEOF THE MALARIAPARASITE S t R , - - I n 1968 I wrote to you about my hypothesis regarding the existence of a virus disease of the malaria parasite, and you were kind enough to publish my letter in Vol. 62 of the same year. It is of interest to note that the same hypothesis has now been proved correct, as reported by DAVIES and HOWELLS (1971) and by TERZAKIS (1969). As I suggested earlier (1968), this virus disease is a natural agent for the destruction of malaria parasites, and an intensive study of the problem may provide a means of biological control of the malaria parasite. It will be recalled that I demonstrated and described (1958, 1959) Feulgen-positive inclusion bodies in the degenerating o6cysts of Plasmodium cynomolgi bastianellii, and also in Plasmodium gallinaceum. O6cysts harbouring such inclusion bodies suffered loss of nuclei and dead o6cysts exhibited a black pigment mass. It would appear that the so-called Ross's black spores may represent o6cysts killed by the virus. Further investigation may ctarit~" this point. I am, etc., B. DASGUPTA, D e p a r t m e n t of Zoology, G o v e r n m e n t College, Darjeeling, 8 June, 1971 India. REFERENCES
DASGUPTA,B. (1958). Trans. R. Soc. trop. Med. Hyg., 52, 9. - (1959). Quart. J. micr. Sci., 100, 241. - (1968). Trans. R. Soc. trop. Med. Hyg., 62, 730. DAVIES, E. E. & HOWELLS, R. E. (1971). Trans. R. Soc. trop. Med. Hyg., 65, 13. TERZAKIS,J. A. (1969). Milit. Med., 134, 10 (suppl.), 916.
THE FIRST ISOLATION OF BUSSUQUARAVIRUSFROM MAN S I R , - - T h e prototype strain of Bussuquara (BSQ), a group B arbovirus, was isolated from a sentinel monkey in Brazil in 1956 (GOMES and CAUSEY, 1959). T h i s virus was shown to be widespread among Proechimys rodents in the same area (SHOPE, 1963). However, no isolations have been reported from h u m a n subjects. Strains closely related to the B S Q virus were repeatedly isolated from different regions in Panama since 1959 from sentinel animals, mosquitoes and rodents (GALINDO et al., 1966; and SRIHONGSEet al., unpublished). T h e present communication reports a natural infection of B S Q virus in a febrile h u m a n resident of Arenosa, a village approximately 30 miles northwest of Panama City, in October 1964. T h e patient, an adult male 29 years old, was ill for 4 days with fever, anorexia, restlessness and joint pain without evidence of inflammation, He complained of chills, profuse sweating and continuous frontal headache. Physical examination revealed only dental caries and a functional systolic m u r m u r , in addition to the low-grade fever. N o other abnormal signs and symptoms were found. A virus was isolated by inoculation of suckling mice with blood serum obtained on the first day of illness. T h e isolated virus was studied by standard serological techniques (haemagglutination-inhibition, complement-fixation and neutralization) and was found to be closely related, if not identical, to the Be An 4116 strain of B S Q virus isolated from Brazil. T h e patient m o v e d out of the village during the convalescent period and we were unable to locate him until about a year later. Results of serological tests performed at that time showed a significant increase in antibody titre both to Bussuquara virus and, to a lesser extent, certain other group B arboviruses. T o determine the prevalence of B S Q virus infection in man, serum surveys of some 1,715 people living in Arenosa and adjacent villages close to the G a t u n Lake region of Central Panama were made. 34% of these individuals exhibited H I antibodies to group B arboviruses, which is a highly cross-reactive group of viruses. At least 20% of these positives showed relatively higher titres to B S Q than to 3 other antigens (Yellow fever, St. Louis encephalitis and Ilheus) included in the tests. F u r t h e r m o r e , neutralization tests were performed with some
542
CORRESPONDENCE
of the BSQ HI-positive sera. From a total of 383 samples tested, 46% were positive. Therefore, it seems very likely that a number of these people have been infected with BSQ virus. Although the BSQ virus isolated from this patient represents the only reported laboratory documented human case, the results of our serological surveys indicate that infection with this virus is probably widespread among the human populations in certain areas in the Republic of Panama. If we consider these findings together with those incriminating Proechimys and Sigmodon rodents as reservoir hosts as well as culicine mosquitoes as potential vectors of BSQ virus in Panama, then we may speculate that BSQ is a medically important virus which could create health hazards to non-immune populations migrating to the endemic areas. We are, etc., NUNTHORN SRIHONGSE, CARL M. JOHNSON, Gorgas Memorial Laboratory, lOJune, 1971 Panama, Republic of Panama.
REFERENCES GALINDO, P., SRIHONGSE,S., RODANICHE,E. DE & GRAYSON,M. A. (1966). Am. J. trop. Med. Hyg., 15, 385. GOMES, G. & CALTSEY,O. R. (1965). Proc. Soc. exp. Biol. Med., 101,275. SHOPE,R. E. (1963). Ann. Microbiol., 11, 167. SRIHONGSE, S., GALINDO,P. & JOHNSON, C. M. (Unpublished).