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First isolation of Congo-crimean haemorrhagic fever virus in Madagascar
Ann. lnst. Pasteur/Virol, 1988, 139, 239-241
9 ELSEVIER Paris 1988
BRIEF N O T E
FIRST ISOLATION OF C O N G O - C R I M E A N HAEMORRHAGIC FEVER VIRUS IN MADAGASCAR C.C. Mathiot (1) (,), D. FonteniUe (1), j.p. Digoutte (2) and P. Coulanges (1) (**) (1) lnstitut Pasteur, BP 1274, Tananarive, and (2) Institut Pasteur, Dakar An epidemiological research program on arboviruses has been in progress in Madagascar since 1976. Extensive serological surveys have demonstrated an active viral circulation, mainly of the flavivirus group, in the human population. Numerous viral strains were isolated from mosquitoes. These strains included two new viral species, several cosmopolitan viruses, such as Sindbis and West Nile, and several African viruses, especially Rift Valley fever virus, which was isolated from mosquitoes caught in a rain forest area [1, 3]. During 1985, 3,216 ticks were collected from cattle in the slaughterhouse in Antananarivo, the capital of Madagascar. Monospecific pools of unfed ticks were constituted and inoculated i.c. into suckling mice for virus isolation attempts. Five viral strains were isolated from 5 out of 135 pools of Boophilus microplus, while all 113 pools of Amblyomma variegatum remained negative. The strains were identified as Congo-Crimean haemorrhagic fever (Congo-CHF) virus by complement fixation and neutralization tests. All but 2 (MgAr951, MgAr955) were re-isolated. Prior to isolation of these strains, the Congo-CHF virus had not been introduced into our laboratory. The main characteristics of the 5 strains are given in table I; they are typical of classical Congo-CHF viruses. These strains represent the first isolation of Congo-CHF virus in Madagascar, and also the first virus isolation from ticks in this country. The tick B. microplus is not known to be a good vector. Nevertheless, it has been demonstrated to be a vector of Babesia bovis and Borrelia theileri
Submitted October 22, 1987, accepted December 2, 1987. (*) Presentaddress: InstitutPasteur. BP 923, Bangui,CAR. (**) To whomcorrespondenceshouldbe addressed.
C.C. MATHIOT AND COLL.
240 TABLE I.
Strain MgAr951 MgAr952 MgAr953 MgAr954 MgAr955
-
-
Characteristics of Congo-CHF virus strains isolated
from B. microplus ticks in Antananarivo.
Date of: Sample isolation log LDs0 (1985) (1986) /0.02 ml i.c. 28/03 28/03 28/03 28/03 31/07
22/06 10/06 17/06 26/06 16/08
4.4 4.7 4.4 3.8 4.4
Suckling mice AST CF test (a) N test (a) (days) 6 7 6 6 6
256/8 (b) 128/4 128/4 128/4 128/4
2.6 (c) > 3.2 2.7 > 2.3 > 2.9
AST = average survival time; CF = complement fixation; N = neutralization. (") Tested against Congo-CHF reference mouse immunascite 81.0115. (b) Reciprocal antibody titre/reciprocal antigen titre. (c) Neutralization index (log).
in Madagascar [7]. Moreover, although it is generally considered as a onehost tick [2], B. microplus has been found in Madagascar on several different hosts: cattle, sheep, goats, horses, dogs and also on humans. Although B. microplus may not play the same vectorial role as Hyalomma, which is not present in Madagascar, in the transmission of Congo-CHF virus, it may play an important epidemiological role in maintaining the virus over a long period. Since the Congo-CHF antigen was not included in the previously mentioned serologic surveys, and in light of the high pathogenicity of this virus which has recently been isolated from h u m a n cases in several African countries [4, 5, 6], there is a need for clinical, serological and epidemiological surveillance of the viral activity in the human population, especially in cattle-breeding areas. KEY-WORDS: Congo-Crimean haemorrhagic fever virus, Boophilus, Madagascar; First isolation.
RI~SUMI~ P R E M I E R ISOLEMENT DU VIRUS C O N G o - C H F
A MADAGASCAR
Cinq souches de virus Congo-Crim6e de la fi6vre h~morragique ont &~ isol~es A partir de lots de tiques Boophilus microplus, r~colt~es sur d~pouilles de bceuf aux abattoirs de Tananarive en 1985.
Congo-CHF = Congo-Crimean haemorrhagic fever. [
i.e. = intracerebrally.
H A E M O R R H A G I C F E V E R VIRUS I N M A D A G A S C A R
241
Ces souches repr6sentent les premiers isolements de virus Congo-CHF, ainsi que les premiers isolements viraux h partir de tiques, ~t Madagascar. La n6cessit6 d'une surveillance de la circulation virale dans la population humaine est soulign6e. MOTS-CLI~S: Virus Congo-Crim6e de la fi~vre h6morragique, Boophilus, Madagascar; Premiers isolements. REFERENCES
[1] CLERC,Y., RODHAIN,F., DIGOUTTE,J.P., TESH, R., HI,ME, G. & COULANGES, P., Le virus P6rinet du genre Vesiculovirus (Rhabdoviridae) isol6 de culicid6s ~t Madagascar. Ann. Virol. (Inst. Pasteur), 1983, 134 E, 61-71. [2] HOOCSTRAAL,H., The epidemiology of tick-borne Crimean-Congo haemorrhagic fever in Asia, Europe and Africa. J. Med. Entomol., 1979, 15, 307-417. [3] MATHIOT,C., FONTENILLE,D., DIGOUTTE,J.P. & COULANGES,P., A propos de l'isolement de deux arbovirus africains ~t partir de moustiques end6miques de Madagascar. Bull. Soc. Path. exot., 1986, 79, 334-341. [4] SALUZZO,J.F:, DIGOUYrE,J:P:, CORNET,M., BAUDON,D., Roux, J. & ROBERT, V., Isolation of Crimean-Congo haemorrhagic fever and Rift Valley fever viruses in Upper Volta. Lancet, 1984, I, 1179. [5] SALUZZO,J.F., AUBRY,P., MCCORMICK,J.B. & DIGOUTTE,J.P., Haemorrhagic fever caused by Crimean-Congo haemorrhagic fever virus in Mauritania. Trans. roy. Soc. trop. Med. Hyg., 1985, 79, 268. [6] SWANEPOEL,R., SHEPERD,A.J., LEMAN, P.A., SHEPERD, S.P., McGILLIVRAY, G.M., ERASMUS,M.J., SEARLE, L.A. & GILL, D.E., Epidemiologic and clinical features of Crimean-Congo haemorrhagic fever in Southern Africa. Amer. J. trop. ivied. Hyg., 1987, 36, 120-132. [7] UILENBERG,G., HOOGSTRAAL,H. & KLEIN, J.M., Les tiques (Ixodoidea) de Madagascar et leur r61e vecteur. Arch. Inst. Pasteur Madagascar, 1979, Num6ro Sp6cial.
9 ELSEVIER Paris 1988
BRIEF N O T E
FIRST ISOLATION OF C O N G O - C R I M E A N HAEMORRHAGIC FEVER VIRUS IN MADAGASCAR C.C. Mathiot (1) (,), D. FonteniUe (1), j.p. Digoutte (2) and P. Coulanges (1) (**) (1) lnstitut Pasteur, BP 1274, Tananarive, and (2) Institut Pasteur, Dakar An epidemiological research program on arboviruses has been in progress in Madagascar since 1976. Extensive serological surveys have demonstrated an active viral circulation, mainly of the flavivirus group, in the human population. Numerous viral strains were isolated from mosquitoes. These strains included two new viral species, several cosmopolitan viruses, such as Sindbis and West Nile, and several African viruses, especially Rift Valley fever virus, which was isolated from mosquitoes caught in a rain forest area [1, 3]. During 1985, 3,216 ticks were collected from cattle in the slaughterhouse in Antananarivo, the capital of Madagascar. Monospecific pools of unfed ticks were constituted and inoculated i.c. into suckling mice for virus isolation attempts. Five viral strains were isolated from 5 out of 135 pools of Boophilus microplus, while all 113 pools of Amblyomma variegatum remained negative. The strains were identified as Congo-Crimean haemorrhagic fever (Congo-CHF) virus by complement fixation and neutralization tests. All but 2 (MgAr951, MgAr955) were re-isolated. Prior to isolation of these strains, the Congo-CHF virus had not been introduced into our laboratory. The main characteristics of the 5 strains are given in table I; they are typical of classical Congo-CHF viruses. These strains represent the first isolation of Congo-CHF virus in Madagascar, and also the first virus isolation from ticks in this country. The tick B. microplus is not known to be a good vector. Nevertheless, it has been demonstrated to be a vector of Babesia bovis and Borrelia theileri
Submitted October 22, 1987, accepted December 2, 1987. (*) Presentaddress: InstitutPasteur. BP 923, Bangui,CAR. (**) To whomcorrespondenceshouldbe addressed.
C.C. MATHIOT AND COLL.
240 TABLE I.
Strain MgAr951 MgAr952 MgAr953 MgAr954 MgAr955
-
-
Characteristics of Congo-CHF virus strains isolated
from B. microplus ticks in Antananarivo.
Date of: Sample isolation log LDs0 (1985) (1986) /0.02 ml i.c. 28/03 28/03 28/03 28/03 31/07
22/06 10/06 17/06 26/06 16/08
4.4 4.7 4.4 3.8 4.4
Suckling mice AST CF test (a) N test (a) (days) 6 7 6 6 6
256/8 (b) 128/4 128/4 128/4 128/4
2.6 (c) > 3.2 2.7 > 2.3 > 2.9
AST = average survival time; CF = complement fixation; N = neutralization. (") Tested against Congo-CHF reference mouse immunascite 81.0115. (b) Reciprocal antibody titre/reciprocal antigen titre. (c) Neutralization index (log).
in Madagascar [7]. Moreover, although it is generally considered as a onehost tick [2], B. microplus has been found in Madagascar on several different hosts: cattle, sheep, goats, horses, dogs and also on humans. Although B. microplus may not play the same vectorial role as Hyalomma, which is not present in Madagascar, in the transmission of Congo-CHF virus, it may play an important epidemiological role in maintaining the virus over a long period. Since the Congo-CHF antigen was not included in the previously mentioned serologic surveys, and in light of the high pathogenicity of this virus which has recently been isolated from h u m a n cases in several African countries [4, 5, 6], there is a need for clinical, serological and epidemiological surveillance of the viral activity in the human population, especially in cattle-breeding areas. KEY-WORDS: Congo-Crimean haemorrhagic fever virus, Boophilus, Madagascar; First isolation.
RI~SUMI~ P R E M I E R ISOLEMENT DU VIRUS C O N G o - C H F
A MADAGASCAR
Cinq souches de virus Congo-Crim6e de la fi6vre h~morragique ont &~ isol~es A partir de lots de tiques Boophilus microplus, r~colt~es sur d~pouilles de bceuf aux abattoirs de Tananarive en 1985.
Congo-CHF = Congo-Crimean haemorrhagic fever. [
i.e. = intracerebrally.
H A E M O R R H A G I C F E V E R VIRUS I N M A D A G A S C A R
241
Ces souches repr6sentent les premiers isolements de virus Congo-CHF, ainsi que les premiers isolements viraux h partir de tiques, ~t Madagascar. La n6cessit6 d'une surveillance de la circulation virale dans la population humaine est soulign6e. MOTS-CLI~S: Virus Congo-Crim6e de la fi~vre h6morragique, Boophilus, Madagascar; Premiers isolements. REFERENCES
[1] CLERC,Y., RODHAIN,F., DIGOUTTE,J.P., TESH, R., HI,ME, G. & COULANGES, P., Le virus P6rinet du genre Vesiculovirus (Rhabdoviridae) isol6 de culicid6s ~t Madagascar. Ann. Virol. (Inst. Pasteur), 1983, 134 E, 61-71. [2] HOOCSTRAAL,H., The epidemiology of tick-borne Crimean-Congo haemorrhagic fever in Asia, Europe and Africa. J. Med. Entomol., 1979, 15, 307-417. [3] MATHIOT,C., FONTENILLE,D., DIGOUTTE,J.P. & COULANGES,P., A propos de l'isolement de deux arbovirus africains ~t partir de moustiques end6miques de Madagascar. Bull. Soc. Path. exot., 1986, 79, 334-341. [4] SALUZZO,J.F:, DIGOUYrE,J:P:, CORNET,M., BAUDON,D., Roux, J. & ROBERT, V., Isolation of Crimean-Congo haemorrhagic fever and Rift Valley fever viruses in Upper Volta. Lancet, 1984, I, 1179. [5] SALUZZO,J.F., AUBRY,P., MCCORMICK,J.B. & DIGOUTTE,J.P., Haemorrhagic fever caused by Crimean-Congo haemorrhagic fever virus in Mauritania. Trans. roy. Soc. trop. Med. Hyg., 1985, 79, 268. [6] SWANEPOEL,R., SHEPERD,A.J., LEMAN, P.A., SHEPERD, S.P., McGILLIVRAY, G.M., ERASMUS,M.J., SEARLE, L.A. & GILL, D.E., Epidemiologic and clinical features of Crimean-Congo haemorrhagic fever in Southern Africa. Amer. J. trop. ivied. Hyg., 1987, 36, 120-132. [7] UILENBERG,G., HOOGSTRAAL,H. & KLEIN, J.M., Les tiques (Ixodoidea) de Madagascar et leur r61e vecteur. Arch. Inst. Pasteur Madagascar, 1979, Num6ro Sp6cial.