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The dog as a reservoir of visceral Ieishmaniasis in Kenya
447 TRANSACTIONS OF THE ROYAL SOCIETY OF TROPICAL MEDICINE AND HYGIENE, VOL. 71, NO. 5, 1977.
Correspondence To the Editor
in Kerala and Tamilnadu States of India (1960-75) SIR-The World Health Organization (1964) recognized the large gaps still apparent in our knowledge of epidemiology and other aspects of Plasmodium malariae and felt that much investigation in the way of experiments and field work in these respects were still needed. JASWANT SING et al. (1952) had recorded the distribution of species of human plasmodia in different States of India from the studies of malaria surveys done at that time. The present note describes the behaviour of P. malariae in the areas of Tamil Nadu and Kerala States which had a high endemicity prior to the launching of the National Malaria Control Programme in 1953 which was subsequently converted to the National Malaria Eradication Programme from 1958. Surveillance operations under the eradication programme started from 1960. Mass blood surveys were conducted around each positive case to bring out other co-related cases if any. Epidemiological data from 1953-60 were not available.
Plasmodium
malariae
Prevalence of P. malariae in Kerala and Tamilnadu States, India Period 1946-49 Period 1960-75 (a) Kerala State 44.0% Nil. i. Cochin (1949) Two cases in 1969 ii. Travancore (1946-47) 70.0% (Trivandrum Dist.). iii. Malabar Dist. 13.0% Palghat-1 (1961), Kozhikode-4 (1 in 1961,3 in 1962).All thecases classified as relapse. (b) Tamilnadu State i. North Arcot 28.0% Nil. Dist. ii. Nilgiris West Dist. 26.0% Nil. iii. Nilgiris East Dist. 75.0% Nil. iv. Tiruchirapalli Dist. 40.0% 1 in 1960, 1 in 1961 (both cases unclassified). v. Coimbatore Dist. Nil 1 case in Tiruppur Division. The above data show that P. malariae has probably been completely eradicated in both the States after the launching of the eradication programme. Whether a few asymptomatic but undetected cases are still persisting is not known. The erstwhile Cochin and Travancore areas of the present Kerala State had no indigenous malaria case of any species from 1962-75. In areas noted for Tamilnadu State there were no indigenous cases of any species from 1964 onwards except a few P. vivax cases recorded in two towns of Tiruchirapalli District (Tiru-
chirapalli and Karur). It is interesting to note that in the neighbouring Karnataka State there was a small focal outbreak of P. malariae in 1969. Numbers of P. malariae cases recorded between 1961-68 and 1968-72 were 330 and 374 respectively in Karnataka State @HTR et al., 1969; ROY et al., 1976). We are, etc., R. G. ROY Regional National V Block, Bangalore
Coordinating Organisation, Malaria Eradication Programme, Jayanagar, 560 041. K. P. CHAKRAPANI Director of Health Services and Family Planning, 81 Mount Road, Madras 600 006 JOSEPI~ZACHARIAS Directorate of Health Services, Trivandrum 695 001
References Dhir, S. L., Arora, R. R., Nanjundiah, K. S., Roy, R. G. & Scrivastava, H. M. L. (1969). Focal outbreak of malaria caused by Plasmodium malariae in Tumkur District, Mysore State. Journal of Communicable Diseases, 1, 139-151. Jaswant Singh, Krishnaswami, A. K. & Ramakrishnan, S. P. (1952). The distribution of human plasmodia in India. Indian Journal of Malariology, 6 (4), 415-433. Roy, R. G., Madesayya, N. M., Sitaraman, N. L. & Ghosh, R. B. (1976). Plasmodium malariae infection in Karnataka State (1968-72). Journal of Communicable Diseases, 8, 81-82. World Health Organization (1964). Technical Report Series No. 272, WHO Expert Committee on Malaria, 10th Report, p. 39.
The dog as a reservoir of visceral leishmaniasis in Kenya SIR-The pattern of visceral leishmaniasis outbreaks in Kenya where cases have sprung up sporadically suggests strongly that the disease is a form of zoonosis. Dogs are known to be reservoirs of infantile visceral leishmaniasis in the Mediterranean region and to play a role in the transmission of kala-azar in the New World. 100 dogs were among the animals which were examined by Heisch (1954) in Tseikuru. Kitui District. Kenya, but all of the’dogs were found negative for the disease: Epidemiological studies carried out by SOUTHGATE & OREDO (1962) in Kitui District revealed that there was a correlation between the incidence of kala-azar in domestic animals, including dogs, kept in homesteads. WIJERS & MWANGI (1966), investigating kala-azar epidemiology in Kathangacini, Meru District, Kenya, observed a positive correlation of the disease incidence and the domestic animals. All previous investigations for animal reservoirs have met with negative results as
448
CORRESPONDENCE
far as domestic animals are concerned. While working on the dynamics of the transmission of visceral leishmaniasis in an endemic area of Kacheliba, Rift Valley, Kenya, which has a high incidence of the disease, we found a domestic dog caught in one of our traps which was meant for wild carnivores. Out of curiosity, we decided to include it in our investigation and killed it, made cultures of the blood, spleen, liver and kidney in the NNN diphasic medium and took smears of these tissues. On examination of the medium after seven days, the spleen culture was found positive for comparable promastigotes. On examination of the stained tissues, all except the blood were found positive for L.D. bodies. Although a full transmission from man to man has not been carried out with this strain, we feel that this evidence and the fact that the dog is already known as a reservoir of visceral leishmaniasis elsewhere, warrants the statement that the dog appears to be one of the animal reservoirs of visceral leishmaniasis in Kacheliba. Rift Valley, Kenya. This investigation received financial support from WHO and the Ministrv of Health. Kenva. We are, etc., J. M. NGOKA MUTUKU J. MUTINGA Department of Entomology, University of Nairobi, Kenya.
References Heisch, R. B. (1954). Studies in leishmaniasis in East Africa. I. The epidemiology of an outbreak of kala-azar in Kenya. Transactions of the Royal Society of Tropical Medicine
and Hygiene, 48,449-464.
Southgate, B. A. & Oriedo, B. V. E. (1962). Studies in the epidemiology of East African leishmaniasis. I. The circumstantial epidemiology of kala-azar in the Kitui district of Kenya. Transactions of the Royal Society of Tropical Medicine
and Hygiene, 56, 30-47.
Wijers, D. J. B. & Mwangi, S. (1966). Studies on the vector of kala-azar in Kenya. VI. Environmental epidemiology in Meru district. Annals of Tropical Medicine
and Parasitology,
Accepted for publication
60, 373-391.
,
8th May, 1977.
Serological evidence for the geographical distribution of Trypanosoma vivax in the New World SIR-Trypanosoma vivax Ziemann, 1905 is widely distributed throughout the tsetse fly areas of Africa. Within the last 60 years this trypanosome has also been reported in all of the Latin American countries with an Atlanticcoast-line from Panama in the west to Belem in Brazil to the east. Reports also exist from the two West Indian islands of Guadalupe and Martinique (SHAW& LAINSON, 1972). Identification of the parasite has been based on morphology, host range and pathogenic&. However, the total observations are still fragmentary and to the present time no sustained studies exist attempting to answer any basic questions. These concern the relationship of Old and New World isolations, the true geoaravhical distribution of the infection in the absence of tsetse, and the economic significance to the livestock industry (CLARKSON,1976). Serological tests have been little used as epidemiological tools (WELLS,BETANCOURT & PAGE, 1970) but current results from an indirect
fluorescent antibody test here reported have probably revealed a far wider distribution of the infection in the New World than previously recognized. Two modifications were made to an indirect fluorescent antibody test recently described and evaluated (PLATT & ADAMS, 1976). The first was the use of air dried antigen slides without recourse to fixation. The second was the use of nail varnish to delineate wells on the antigen slides preventing sera from spreading to adjacent positions. The modifications were borrowed from a similar test for Babesia spp. (TODOROVIC & LONG, 1976). Antigen was prepared from a strain of T. vivax isolated from the Cauca Valley, Colombia. Using the facility of the serum bank maintained at the Centro International de Agricultura Tropical, the following numbers of serum samples were assembled: El Salvador, 100; Costa Rica, 192; Colombia, 3,324; Ecuador, 310; Peru, 49; Brazil (Mato Grosso), 666 and Paraguay, 15. A minimum of ten and a maximum of 20 serum samples were taken at random from cattle at each farm included in the survey to enable the presence or absence of the infection to be established. Antibodies to T. vivax were found in sera from all of the participating countries. The over-all percentages were: El Salvador, 15 %, Costa Rica, 22.9 %; Colombia, 48.2%; Ecuador, 22.5%; Peru, 14.3%; Brazil, 54% and Paraguay, 40%. The significance of these figures, and variations between and within countries will be discussed elsewhere. However, even in crude form they enable a new mainland distribution of T. vivax to be postulated as extending from at least 12”N down to the tropic of Capricorn. A definitive description of the geographical distribution of T. vivax will depend on further examination of the specificity of the indirect fluorescent antibody test to include a wider range of infections than those already checked by PLATT & ADAMS (1976). They found no cross reactivity when sera from calves singularly infected with Trypanosoma theileri, T. evansi, Anaplasma marginale, Babesia argentina, B. bigemina and Eperythrozoon spp.
were similarly tested. Moreover, it will depend on the demonstration of the trypanosome by direct means in all areas from which positive sera have been obtained. In this respect blood smears containing trypanosomes morphologically resembling T. vivax have already been received from Pucallpa in Peru. We are, etc., E. A. WELLS Centro International de Agricultura Apartado A&eo 67-13, Cali, Colombia.
Tropical,
ANTONIOBETAMCOURT Znstituto Colombiano Agropecuario, Apartado A&e0 206, Monteria, Colombia.
LUIS ED~ARDOR~IREZ Facultad de Medicina, Universidad de Antioquia, Apartado A&eo 883, Medellin, Colombia.
References Clarkson, M. J. (1976). Trypanosomiasis of domesticated animals in South America. 16th Seminar on trypanosomiasis. Transactions of the Royal Society for Tropical Medicine and Hygiene, 70, 125-126. Platt, K. B. & Adams, L. G. (1976). Evaluation of the indirect fluorescent antibody test for detecting Trypano-
Correspondence To the Editor
in Kerala and Tamilnadu States of India (1960-75) SIR-The World Health Organization (1964) recognized the large gaps still apparent in our knowledge of epidemiology and other aspects of Plasmodium malariae and felt that much investigation in the way of experiments and field work in these respects were still needed. JASWANT SING et al. (1952) had recorded the distribution of species of human plasmodia in different States of India from the studies of malaria surveys done at that time. The present note describes the behaviour of P. malariae in the areas of Tamil Nadu and Kerala States which had a high endemicity prior to the launching of the National Malaria Control Programme in 1953 which was subsequently converted to the National Malaria Eradication Programme from 1958. Surveillance operations under the eradication programme started from 1960. Mass blood surveys were conducted around each positive case to bring out other co-related cases if any. Epidemiological data from 1953-60 were not available.
Plasmodium
malariae
Prevalence of P. malariae in Kerala and Tamilnadu States, India Period 1946-49 Period 1960-75 (a) Kerala State 44.0% Nil. i. Cochin (1949) Two cases in 1969 ii. Travancore (1946-47) 70.0% (Trivandrum Dist.). iii. Malabar Dist. 13.0% Palghat-1 (1961), Kozhikode-4 (1 in 1961,3 in 1962).All thecases classified as relapse. (b) Tamilnadu State i. North Arcot 28.0% Nil. Dist. ii. Nilgiris West Dist. 26.0% Nil. iii. Nilgiris East Dist. 75.0% Nil. iv. Tiruchirapalli Dist. 40.0% 1 in 1960, 1 in 1961 (both cases unclassified). v. Coimbatore Dist. Nil 1 case in Tiruppur Division. The above data show that P. malariae has probably been completely eradicated in both the States after the launching of the eradication programme. Whether a few asymptomatic but undetected cases are still persisting is not known. The erstwhile Cochin and Travancore areas of the present Kerala State had no indigenous malaria case of any species from 1962-75. In areas noted for Tamilnadu State there were no indigenous cases of any species from 1964 onwards except a few P. vivax cases recorded in two towns of Tiruchirapalli District (Tiru-
chirapalli and Karur). It is interesting to note that in the neighbouring Karnataka State there was a small focal outbreak of P. malariae in 1969. Numbers of P. malariae cases recorded between 1961-68 and 1968-72 were 330 and 374 respectively in Karnataka State @HTR et al., 1969; ROY et al., 1976). We are, etc., R. G. ROY Regional National V Block, Bangalore
Coordinating Organisation, Malaria Eradication Programme, Jayanagar, 560 041. K. P. CHAKRAPANI Director of Health Services and Family Planning, 81 Mount Road, Madras 600 006 JOSEPI~ZACHARIAS Directorate of Health Services, Trivandrum 695 001
References Dhir, S. L., Arora, R. R., Nanjundiah, K. S., Roy, R. G. & Scrivastava, H. M. L. (1969). Focal outbreak of malaria caused by Plasmodium malariae in Tumkur District, Mysore State. Journal of Communicable Diseases, 1, 139-151. Jaswant Singh, Krishnaswami, A. K. & Ramakrishnan, S. P. (1952). The distribution of human plasmodia in India. Indian Journal of Malariology, 6 (4), 415-433. Roy, R. G., Madesayya, N. M., Sitaraman, N. L. & Ghosh, R. B. (1976). Plasmodium malariae infection in Karnataka State (1968-72). Journal of Communicable Diseases, 8, 81-82. World Health Organization (1964). Technical Report Series No. 272, WHO Expert Committee on Malaria, 10th Report, p. 39.
The dog as a reservoir of visceral leishmaniasis in Kenya SIR-The pattern of visceral leishmaniasis outbreaks in Kenya where cases have sprung up sporadically suggests strongly that the disease is a form of zoonosis. Dogs are known to be reservoirs of infantile visceral leishmaniasis in the Mediterranean region and to play a role in the transmission of kala-azar in the New World. 100 dogs were among the animals which were examined by Heisch (1954) in Tseikuru. Kitui District. Kenya, but all of the’dogs were found negative for the disease: Epidemiological studies carried out by SOUTHGATE & OREDO (1962) in Kitui District revealed that there was a correlation between the incidence of kala-azar in domestic animals, including dogs, kept in homesteads. WIJERS & MWANGI (1966), investigating kala-azar epidemiology in Kathangacini, Meru District, Kenya, observed a positive correlation of the disease incidence and the domestic animals. All previous investigations for animal reservoirs have met with negative results as
448
CORRESPONDENCE
far as domestic animals are concerned. While working on the dynamics of the transmission of visceral leishmaniasis in an endemic area of Kacheliba, Rift Valley, Kenya, which has a high incidence of the disease, we found a domestic dog caught in one of our traps which was meant for wild carnivores. Out of curiosity, we decided to include it in our investigation and killed it, made cultures of the blood, spleen, liver and kidney in the NNN diphasic medium and took smears of these tissues. On examination of the medium after seven days, the spleen culture was found positive for comparable promastigotes. On examination of the stained tissues, all except the blood were found positive for L.D. bodies. Although a full transmission from man to man has not been carried out with this strain, we feel that this evidence and the fact that the dog is already known as a reservoir of visceral leishmaniasis elsewhere, warrants the statement that the dog appears to be one of the animal reservoirs of visceral leishmaniasis in Kacheliba. Rift Valley, Kenya. This investigation received financial support from WHO and the Ministrv of Health. Kenva. We are, etc., J. M. NGOKA MUTUKU J. MUTINGA Department of Entomology, University of Nairobi, Kenya.
References Heisch, R. B. (1954). Studies in leishmaniasis in East Africa. I. The epidemiology of an outbreak of kala-azar in Kenya. Transactions of the Royal Society of Tropical Medicine
and Hygiene, 48,449-464.
Southgate, B. A. & Oriedo, B. V. E. (1962). Studies in the epidemiology of East African leishmaniasis. I. The circumstantial epidemiology of kala-azar in the Kitui district of Kenya. Transactions of the Royal Society of Tropical Medicine
and Hygiene, 56, 30-47.
Wijers, D. J. B. & Mwangi, S. (1966). Studies on the vector of kala-azar in Kenya. VI. Environmental epidemiology in Meru district. Annals of Tropical Medicine
and Parasitology,
Accepted for publication
60, 373-391.
,
8th May, 1977.
Serological evidence for the geographical distribution of Trypanosoma vivax in the New World SIR-Trypanosoma vivax Ziemann, 1905 is widely distributed throughout the tsetse fly areas of Africa. Within the last 60 years this trypanosome has also been reported in all of the Latin American countries with an Atlanticcoast-line from Panama in the west to Belem in Brazil to the east. Reports also exist from the two West Indian islands of Guadalupe and Martinique (SHAW& LAINSON, 1972). Identification of the parasite has been based on morphology, host range and pathogenic&. However, the total observations are still fragmentary and to the present time no sustained studies exist attempting to answer any basic questions. These concern the relationship of Old and New World isolations, the true geoaravhical distribution of the infection in the absence of tsetse, and the economic significance to the livestock industry (CLARKSON,1976). Serological tests have been little used as epidemiological tools (WELLS,BETANCOURT & PAGE, 1970) but current results from an indirect
fluorescent antibody test here reported have probably revealed a far wider distribution of the infection in the New World than previously recognized. Two modifications were made to an indirect fluorescent antibody test recently described and evaluated (PLATT & ADAMS, 1976). The first was the use of air dried antigen slides without recourse to fixation. The second was the use of nail varnish to delineate wells on the antigen slides preventing sera from spreading to adjacent positions. The modifications were borrowed from a similar test for Babesia spp. (TODOROVIC & LONG, 1976). Antigen was prepared from a strain of T. vivax isolated from the Cauca Valley, Colombia. Using the facility of the serum bank maintained at the Centro International de Agricultura Tropical, the following numbers of serum samples were assembled: El Salvador, 100; Costa Rica, 192; Colombia, 3,324; Ecuador, 310; Peru, 49; Brazil (Mato Grosso), 666 and Paraguay, 15. A minimum of ten and a maximum of 20 serum samples were taken at random from cattle at each farm included in the survey to enable the presence or absence of the infection to be established. Antibodies to T. vivax were found in sera from all of the participating countries. The over-all percentages were: El Salvador, 15 %, Costa Rica, 22.9 %; Colombia, 48.2%; Ecuador, 22.5%; Peru, 14.3%; Brazil, 54% and Paraguay, 40%. The significance of these figures, and variations between and within countries will be discussed elsewhere. However, even in crude form they enable a new mainland distribution of T. vivax to be postulated as extending from at least 12”N down to the tropic of Capricorn. A definitive description of the geographical distribution of T. vivax will depend on further examination of the specificity of the indirect fluorescent antibody test to include a wider range of infections than those already checked by PLATT & ADAMS (1976). They found no cross reactivity when sera from calves singularly infected with Trypanosoma theileri, T. evansi, Anaplasma marginale, Babesia argentina, B. bigemina and Eperythrozoon spp.
were similarly tested. Moreover, it will depend on the demonstration of the trypanosome by direct means in all areas from which positive sera have been obtained. In this respect blood smears containing trypanosomes morphologically resembling T. vivax have already been received from Pucallpa in Peru. We are, etc., E. A. WELLS Centro International de Agricultura Apartado A&eo 67-13, Cali, Colombia.
Tropical,
ANTONIOBETAMCOURT Znstituto Colombiano Agropecuario, Apartado A&e0 206, Monteria, Colombia.
LUIS ED~ARDOR~IREZ Facultad de Medicina, Universidad de Antioquia, Apartado A&eo 883, Medellin, Colombia.
References Clarkson, M. J. (1976). Trypanosomiasis of domesticated animals in South America. 16th Seminar on trypanosomiasis. Transactions of the Royal Society for Tropical Medicine and Hygiene, 70, 125-126. Platt, K. B. & Adams, L. G. (1976). Evaluation of the indirect fluorescent antibody test for detecting Trypano-