Notes on Salmonella Infections in Animals in Ghana

Res. vet. Sci., 1962, 3, 460

Notes on Salmonella Infections In Animals In Ghana D. ZWART Veterinary Section, School of Agriwlwre, Kurame NkTlllllah University, Kumasi, Ghana

SUMMARY. During investigations in the Salmonella carrier rate ojdifferent animals in Ghana, 21· 3 per cent ojthe cattle, 3·7 per cent ojthe sheep, 5"0 per cent ojthegoats, 7.0 per cent oj the pigs, 8·3 per cent oj the dogs, 8·6 percent ojthe rodents, 37·5 percent oj the lizards, and 29.6 per cent oj thesnakes examined werefound to be injected. Smalloutbreaks oj disease are noted among poultry, in a monkey, a chimpanzee, an Indian elephant and a dwarfbuffalo calf. Eleven strains oJSalmonella with hitherto unknown antigenic patterns, were isolated. the distribution of Salmonella infections in animals in Ghana is rare (Table II). A knowledge of the distribution of these organisms is of great importance, not only from the viewpoint of animal health, but also because of their risks to man. Not only may animal products contain Salmonella organisms, but products of plant origin may also be contaminated by animals with Salmonellae in their faeces. This survey was intended primarily to gain some insight into the role of animals as Salnionella carriers. As ours is not a diagnostic laboratory, little material was received from field outbreaks of salmonellosis, although we were consulted in some cases. In consequence, these clinical outbreaks (see Table VII) do not represent a complete picture of salmonellosis as a diseaseproblem in Ghana. During our survey Salmonella organisms were isolated from clinically-healthy cattle, pigs, rodents, dogs, sheep, goats, snakes and lizards. The strains from poultry, a monkey, a chimpanzee, a dwarf buffalo calf and an Indian elephant were isolated from the faeces or the systematic organs of clinically-affected animals. INFORMATION CONCERNING

MATERIALS AND METHODS

Sampling Techniques The cattle from which we collected our material were brought either on foot or by lorry from Mali, Haute-Volta and Northern Ghana to the Kumasi municipal slaughterhouse. The duration of the journey varied from a few days to 2 months according to the distance and means of transport. No attempt was made to classify the cattle according to their origin. After slaughter, small pieces of the portal and mesenteric lymph-nodes and scrapings from the mucosae of the small intestine, ileo-caecal valve, colon, rectum and gall bladder were collected. Similar samples from sheep and goat carcases were obtained in the same way in this slaughterhouse. The material from pigs was taken from those slaughtered at the Kumasi slaughterhouse and from pigs kept and slaughtered at the University experimental farm. The pigs at the Kumasi municipal slaughterhouse came mainly from agricultural stations and from wellknown pig breeders. As butchers are reluctant to buy pigs kept under the unhygienic conditions in the villages because of the risk of condemnation of the carcase infected with Cysticercus celluiosae, it was not possible to obtain much material from pigs kept under village conditions. Material for bacteriological examination from pigs was collected from the same sites as from cattle.

Salmonella Infections in Animals in Ghana The rats and mice were caught in different habitats (houses, swamps, grassland, forest, farms) and in Table V they have been classified according to their degree of association with man and domestic animals. After flaming of the skin, material from the rodents was obtained from the small intestine, caecum, colon, rectum and liver with parts of the portal lymph-nodes and gall bladder. The samples from dogs were collected by means of rectal swabs from animals presented for rabies vaccination, which came from, Kumasi and nearby villages. TABLE

I

LIST OF NON-DOMESTICATED SPECIES EXAMINED FOR SALMONELLA

Black rat Bristle-haired tree rat Brush-furred forest mouse Chimpanzee Climbing wood mouse Colobus monkey Dwarf buffalo Indian elephant Kemp's gerbil Multimammate rat Pygmy mouse Small dormouse Spotted grass mouse Three-striped mouse Tullberg's rat Black tree snake Common lizard File snake Forest Cobra Gaboon viper Olive grass snake Rhinoceros viper Rhombic night-adder Royal python Spotted wood snake

Mammals Rattus (Rattus) r. rattus Linnaeus Rattus (Dephomys) deJua Miller Lophurolllys s. sikapusi Temminck Pall troglodytes verus Schwartz Rattus (Hylomyscus) stella Thomas Colobus polykomos vellerosus E. Geoffroy Syneerus eaffer nanus Boddaert Elephas maximus Linnaeus Tatera k. kempi Wroughton Rattus (Mastomys) natalensis crythrolcucus Temminck M,lS minutiodes museuloides Temminck Graphiurus sputrelli Dollman

Lemniscomys s. strlatus Linnaeus Hybomys t. trivirgatus Temminck Rattus (Praomys) moria tullbergi Thomas

Reptiles Thrasops oecidentalis Parker Agama a. agama Linnaeus Mehelya porosis Smith Naja melanoleuca Hallowell Bitis g. gabolliea Dumeril & Bibron Psammophls sibilans phillipsii Hallowell Bitis nasicomls Shaw Causlls rhombeatus Lichtenstein Phytholl regius Shaw Philothamnus s. semivarieyatus Smith

Lizards (Agallla agama Linnaeus) were caught in and around Kumasi, near houses, farm buildings, and on the roads. After flaming the outside of the body, material was taken from the small intestine, caecum, rectum and liver including the gall bladder. The snakeswere killed mainly in and around the University compound, but also in Kumasi and Northern and Southern Ghana. A rectal swab was taken from living specimens, but in dead specimens material was obtained from the lower part of the intestine. All these animals had no symptoms suggestive of salmonellosis and the carcases of the cattle, sheep, goats and pigs (apart from condemnation due to cysticercosis, liver flukes, etc.) were passed for human consumption. An old ulcer in the colon was found in one bacteriologically-positive lizard.

D. Zwart The technique used in the clinical outbreaks of salmonellosis was the same as that described above.

Bacteriological Technique No attempts were made to separate the material coming from different parts of an animal's body (see above), and all the samples from one animal were placed in a jar containing tetrathionate broth (Dileo) to which brilliant green (I :200,000) was added. The broth was incubated for 12-16 hours and then plated out on brilliant green phenol red agar (Dileo) in an I I em. diameter Petri dish. A second plating from the broth was done after 36-40 hours. TABLE II REfERENCES TO SALMONELLA IN ANIMALS IN GHANA

Animal Cattle Chicks

Ducklings Pigs Dog Python

Common lizard

Salm. spec. isolated S. dublin Soparatyphi C S. typhimuriHm { S. virchow S. pullorum S. anatum Salm. spec. S. rubislaw S. takoradi S.legon S. tamale S. akuafo S.ghana S. kokomlemle S. teshie S. newport S. lindenburg S. takoradi S. canastel S. london S. seegefeld S. rubislaw S. alachua S. waycross S. christianborg

Reference Hughes (1954) King and Gellatly (1955) Hughes (1958) Anonymous (1952) Hughes (1958) Stewart (1947) Hughes (1958) Rewell (1948)

Vella (1958)

The plates were incubated and read after 24 and 48 hours. Suspicious colonies were picked, tested againt polyvalent Salmonella 0 serum on slides and inoculated on urea and triple sugar iron agar and in tryptone, glucose, sucrose, lactose and maltose. Those showing positive agglutination and biochemical reactions characteristic of Salmonellae were dispatched on heart infusion agar (Dileo) to the National Salmonella Centre, National Institute of Public Health, Utrecht, Netherlands, where further typing was done according to the Kauffmann-White scheme. RESULTS

The strains isolated and their host distribution will be found in Table III. The rodents and snakes have been subdivided into their different species in Tables V and VI.

Salmonella Injections in Animals ill Ghana TABLE III DISTRIBUTION OF SALMONELLA SEROTYPES IN ANIMALS IN GHANA

Cattle S. aequatoria S. agonal S. ardwick S. ashanti 1 S. berlin S. bredeney S. cairina S. cerro S. chailey S. chandans S. chester S. corvallis S. derby S. dublin S. duisburg S. durban S. elisabethvillc S. enteritidis var chaco

S. gambaga l S. gaminara S.guinea S. baddoll S. johannesburg S. kentucky S. korlebu S. kumasjl s. luke S. malstatt S. mampong 1 S. minnesota S. mlm S. monsthaul S. montevideo S. I/Iundonobo Si nima

S. poona S. pramiso» S. redhill

Sheep

Goats

Pigs

Dogs

Snakes

3 2

3

1

3 1

3 1 1 1 1

2

5

1 1 1

1

7

5

3

6

5 1

8

3

1

1 1 1 1

1

2 2 1 1

\

I

1 2

2

.

2 1 1

1 1 1 1 1 2 1

1

1

8

2

1

1

5

3

2

2

1

1

S.1(mo

S. rubislarv S. sianleyville S. saarbrucke/l S. tafol S. techimani 1 S. teshie S. tilene S. typhinlllrium S. urbana

Rodents Lizards

1 1 1 2 1 1 12 2 1 1

2

continued

D. Zwart TABLE

Cattle

Goats

Pigs

Dogs

Rodents

Lizards Snakes

S. volta I S. vinohrady S. virchow S. IVaI S. lVaycross S. weltevreden S. 3, 10S. I.4:I2:i S. rough

2

Total pos. Total invest.

39 183

3 80

4 80

156

5 60

28 325

51 136

27 91

2I.3 21

3·7

5.0 2

7.0 7

8·3 4

8.6 13

37·5 16

29·6 18

I

I

3 I

I

2 2

I 2

I

Percentage Number of strains 1

Sheep

III continued

I

II

New Salm. serotypes.

Eleven new serotypes were isolated and their antigenic structure and host distribution are presented in Table IV. Further details of these new speciesmay be found in articles by Guinee and Kampelmacher (1961) and Guinee, Kampelmacher and Willems (1961). TABLE IV NEW SALMONELLA SEROTYPES RECOVERED FROM ANIMALS IN GHANA

Name

S. agona S. ashanti S.gambaga S. kumasi S. mampong Sc mim S.pramiso S. tafo S. techimani S. volta S.lVa

Antigen Structure 3,4,12:fgs:-, 28 :b:I,6 21 :Z3S:enz lS 30:z10:enzlS

Host

Cattle Kemp's gerbil Common lizard Olive grass snake Pygmy mouse Common lizard 13,22:Z3S:I,6 Brush-furred forest mouse 13,22:a:I,6 Gaboon viper 3,IO:C:I,7 I,4,I2,27:Z3S: I,7 Cattle Cattle 28;c:z6 Pig I I :r :1,z13z28 Cattle 16;b:I,5

Cattle The figure of 21' 3 per cent infected animals is very high if it is compared with th~ figures of Hughes (1954) who found 2'7 per cent of the gall bladders of slaughtered cattle in Accra (Ghana) to be infected, Collard and Sen (1956) who recorded a 5' 5 per cent infection rate for faeces and mesenteric glands in Ibadan (Nigeria), and Plowright (1957) who found 1 per cent of gall bladders to be infected in cattle on the Central Plateau in Nigeria. Mortelmans (1958) working in the former Belgian Congo stated that in salmonellosis in cattle, the primary organism was S. dublin, while S. enteritidis and S. typhi murium played

Salmonella Infectiotls in Animals in Ghana only secondary roles. However, Wiktor and vanOye (1955), and van Oye, Deom, Vercruysse and Fasseaux (1957) also working in the Congo, isolated considerably more serotypes from symptomless carriers. In Ghana the great number of serotypes (21) found in this survey is also in sharp contrast with the limited number of serotypes recovered from clinical cases of salmonellosis among cattle.

Sheep and Goats

Our figures, although based on a small number of animals, show the relatively low incidence of Salmonella infections among sheep (3'7 per cent) and goats (5 per cent). Johnson (1958) in Nigeria found no carriers among 390 goats and 90 sheep, but described abortion in goats due to S. saintpalll.Jollans (1959) has pointed out that sheep and goat meat is highly favoured in Ghana, and the relative freedom of these animals from Salmonella infections and human pathogenic cysticercosis makes their meat more attractive for human consumption. TABLE V SALMONELLA INFECTIONS IN RODENTS IN GHANA

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s. aCJ,uatoria

S. astanti S. chailey S. duisburg S. enteritidis var. chaco S. kumasi S. luke Sc mlm S. nima S. poona S. rcdhill S. waycross S. weltevreden

Total pos. Total invest.

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2 I I I

3

2 1

1 2

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- -- - - - - -- -- - - -I - - - - - - 2

4

10

1

4

0

1

1

1

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50

50

50

5°

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7

25

13

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(I) Species rarely or never in contact with man or domestic animals, i.e. many forest living forms (2) Species often in contact with farm animals, normally never in houses (3) Species commonly commensal with man

D. Zwart

Pigs The percentage of infected pigs is low (7 per cent). Sen and Collard (1957) working in Ibadan, found 16 per cent of pigs to be infected from which they isolated 3 different serotypes, but their material was collected from one agricultural station. Dogs The infection of the dog depends to some extent on its diet, which in African villages is mainly of plant origin. Mortelmans, Cimpaye, Pinkers and Claeys (1961) working in Ruanda-Urundi found 2"06 per cent of 872 dogs presented for rabies vaccination, to be infected. They quote several other authors who found an infection rate varying from 43"6 per cent in the United States to 1 per cent in some European countries. This variation may be related to the diet. Rodents Although rodents certainly playa role in spreading Salmonella bacteria from one place to another, our figure of 8"6 per cent of animals infected and the serotypes isolated do not suggest that the rodent population as a whole is an important reservoir of infection in Ghana. Commensal and non-commensal rodents do not differ significantly in their infection rate as far as we can judge from our limited material. Collard, Sen and Montefiore (1957) found 3"9 per cent of the rats in Ibadan to be infected and quote several other authors who record infection rates varying from 0"4 per cent (Japan) to 13'4 per cent (India). Lizards The lizard (Agama agama Linnaeus) is abundant in West Africa and it is found near all buildings. The present findings differ to some extent from those of Vella (1958) who collected material mainly from lizard droppings along the coast of Ghana and in Tamale. His figure of positive isolations is lower (22 per cent against 37' 5 per cent) and the distribution of seratypes is completely different from those found in this survey. In fact only S. teshie was common to both surveys, but Vella recovered this organism only once among 40 isolations, whereas in this survey this serotype was found 12 times among 50 isolations. Collard and Montefiore (1956), working in Ibadan, found II"2 per cent of lizards infected, and MacKey (1955) in East Africa records that 48 per cent of the lizards (Hemidactylis mabouia and Mabtlya striata) were positive for Salmonella, but only a few serotypes were the same as the ones found in this survey. Mille, Le Minor and Caponi (1958) in Viet-Nam, found nearly 40 per cent of another type of lizard, Leiolepis bellina gtlttata (Cuvier), to be infected, but stressed the fact that there was a great variation in infection rates and prevalence of serotypes between the different regions of Viet-Nam. Snakes Although a high percentage (29"6 per cent) of snakes were infected, the fact that they may not defaecatefor weeks, makes their role in the spreading of Salmonella bacteria doubtful. Hinshaw and McNeil (1945) working in the United States, however, had strong circumstantial evidence that snakes introduced Salmonella onto a farm, causing losses among turkey poults. The strains isolated in Ghana are not of marked pathogenicity for farm animals, but Africans who eat snakes may become infected.

Salmonella Injections in Animals in Ghana TABLE VI SALMONELLA INFECTIONS IN SNAKES IN GHANA

......

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II)

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'2

OJ

,.;t

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OJ

ii: S. cairina S. chailey S. chester S. dllisburg S. durban S.gllitlea S. kumasi S. luke S. malstatt S. nima S. pramiso Si poona S. remo S. rubislau: S. saarbmcken S. urbana S. vinohrady S. waycross

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Total pos. Total invest.

I

- - - --- - - - ---

I

9

5

27

I2

7 II

---

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0

5

2

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26

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TABLE VII SALMONELLAE ISOLATED FROM DISEASE IN ANIMALS IN GHANA

Total animals involved

Animal Chicken Chicken Chicken Colobus

I II III monkey

Chimpanzee Indian elephant Dwarf buffalo

540 100 100 I I I

I

Mortality 24. 8% 20% 2%

died recovered recovered died

Salm. spec.

S. give S. typhimurium S. haddon S.labadi S.poona S. teddington S. chicago S. rnalstatt

D. Zwart

Clinical Salmonellosis The details of the clinical incidents are summarized in Table VII. The chicks in group I were hatched near Accra and sent by plane to Kumasi where they died at the rate of I-I' 5 per cent a day. After faulty temperature and humidity ranges during incubation and hatching had been corrected, the death rate was reduced to nil and no further Salmonellae could be isolated. The chicks in groups II and III were still dying after treatment for coccidiosis, and S. haddon and S. labadi were isolated from them. The monkey (Colobus polykomos vellerosus, E. Geoflroy), chimpanzee, dwarf buffalo (Syncerus caffer nanus, Boddaert) and Indian elephant were new arrivals in Kumasi, and probably due to the stress of their journey and change of diet went down with salmonellosis. Treatment in the caseof the cured chimpanzee and elephant consistedof furazolidone by mouth and terramycin orally and by injection. DISCUSSION

The limited work that has been done so far in tropical Africa shows that animals may harbour a wide variety of Salmonella serotypes combined in some species with a high carrier rate. The present investigations, although based on relatively small number of animals, confirm these facts. However, much more work needs to be done before there is a clear insight into the epidemiology of salmonellosisin Ghana. The sampling technique is important if adequate comparisons are to be made with the results of other authors. Several authors (Kraneveld, 1947; Galton, Smith, McElrath and Hardy, 1954; Kampelmacher, Guinee, van Keulen and Hofstra, (1961) have stressed the fact that Salmonella bacteria, especiallyin the healthy carrier, have a very uneven distribution in the animal body. A negative result from the gall bladder or faeces does not necessarily mean that the animal is not harbouring any Salmonella bacteria. The exact location of salmonella within the body is not necessarily of epidemiological importance, for the bacteria may eventally be excreted in the faeces or give rise to a septicaemia, and the African habit of eating all parts of the carcase, including the gall bladder and intestines is also relevant to the problem. Another factor contributing to the high incidence of Salmonella infection in cattle may be the close contact in markets and during the journey before the animals are slaughtered. S. agona, for example, was recovered on 2 successive days, but not thereafter, which suggests a contact infection. The limited grazing facilities during the journey to Kumasi and after arrival may also be a contributing factor to the high incidence of Salmonella infection in the Kurnasi slaughterhouse. Sutmoller and Kampelmacher (1957), working in Aruba, found 14 infected animals among 30 cows newly arrived from Middle American countries, but after 3 weeks of grazing on good pasture, only 2 Salmonella strains were recovered from 25 slaughtered cows. Such factors may explain the difference between the figure (2'2 per cent) of Hughes (1954) working in Accra, and those obtained in Kumasi. Infection rates in lizards may be related to geographical distribution if we compare our work with that of Vella (1958), and a survey in the north of Ghana might reveal yet another distribution. Unfortunately it was not possible to get representative samples of poultry kept under different husbandry systems in Ghana such as battery, free range, and deep litter. It is also possible that the figure for pigs would have been different if a greater number of village pigs had been included in our samples.

Salmonella Infections in Animals in Ghana At this moment it is too early to draw firm conclusions about the connection between Salmonella infections in animals and man in Ghana, but it is clear that animals, especially lizards and cattle, are a potential source of infection. ACKNOWLEDGMENTS

I wish to thank the Head of the School of Agriculture, Kwame Nkrumah University of Science and Technology, Associate Professor K. Twum-Barima for his support and permission to publish these investigations. I am indebted to Dr. E. H. Kampelmacher and Mr. P. A. M. Guinee of the National Salmonella Centre (National Institute of Public Health) Utrecht, Netherlands, for their identification of the Salmonella serotypes and their technical advice. I am grateful for the help of Mr. D. H. Barry, lecturer in biology, who trapped and identified the rodents and named the reptiles. Finally, I wish to thank Mr. J. Y. Ansah for his technical assistance in the university veterinary laboratory.

Receivedfor publication Febmary 19t1t 1962

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