Sheikh Technical Veterinary School Mohamed's thesis about Seroprevalence of camel brucellosis in Sheikh district, 2009

Sheikh Technical Veterinary School

STUDY ON

PREVALENCE OF CAMEL

BRUCELLOSIS

IN SHEIKH DISTRICTThesis for Diploma in Livestock Health

Science

BY

MOHAMED HASSAN BARRE

No. 039

25TH JULY 2009

1


Declaration

I am Ahmed Mohamed Egeh declaring here that this work is my

original work, and has not appeared any where else in any other form

except for the references made from other published works.

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Table of content

Introduction……………………………………………………….....

.....1

Literature review

…………………………………………………………3

Methods and Materials....

…………………………………………….5

Animals and data

collection…………………………………………6

Sampling and Sample

processing……………………………….6

Result

…………………………………………………………….............7

Discussion……………………………………………………………

…….10

Conclusion and Recommendation..........................15

Reference……………………………………………………………

………13

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ACKNOWLEDGEMENT

Firstly; I thank Allah for giving me this opportunity, courage and

guidance to complete this research. He makes it possible for things to

happen. I wish to state my gratitude and appreciation to my supervisor

DR: IBRAHIM OSMAN for his encouragement , guidance ,support ,

motivation , constrictive criticism and suggestions which made this

dissertation an invaluable learning experience for me. Without him it

would not have been possible for me to complete this dissertation.

I am also deeply thankful to the pastoralists who provided me the

samples needed without complain which in time made the completion

of the study possible. I wish to acknowledge their contribution.

The researcher is thankful to the Lab technician Mr. Mudasir and his

assistant Mr. Abdikaream for their support.

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Introduction

Somalia economy is largely depended upon livestock accounting for

about 60% of the national income. Camel population is the largest in

Africa, the number recorded being 6.3 million (Refai 2002).

Camels are essential sources of human food and constitute important

supplies of milk, meat and wool, in addition to their use in the

traditional popular racing sport, which is important to the rapidly

growing tourism industry in Arab countries.

Brucellosis is a disease caused by various species of the genus

Brucella; it is the most widely spread zoonotic disease in the world

(Mustafa, M. and P. Nicoletti, 1993). Cross-transmission of brucellosis

can occur between cattle, sheep, goats, camels and other species.

Brucellosis is still endemic in countries of the Mediterranean basin, the

Middle East and central Asia. Human infection due to Brucella from

camels is known to occur mostly through the consumption of un-

pasteurized milk (FAO/WHO, 1986). Camels are frequently infected

with Brucella organisms, especially when they get in contact with

infected large and small ruminants (Radwan, A.I., S.J. Bekairi and P.V.S.

Prasad, 1992). Serological evidence for Brucella infection in camels

has been reported from Asia and Africa (Okoh. A.E.J., 1979). The

relation between Brucella infection and abortion in camels has been

recorded (Higgins, A., 1986). Both Brucella abortus and Brucella

melitensis have been isolated from fetuses, genital discharges,

urine and milk (FAO/WHO, 1986).

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Brucellosis is essentially a herd disease. The clinical presentation in

cattle and water buffalo include abortions in the third trimester

accompanied with retained placentas, metritis, and infertility. Infected

bulls usually contract orchitis and became sterile.

Humans are infected by animals through direct contact of infected

animal tissues, ingestion of infected animal products, or inhalation of

airborne bacteria.

Common sources include fetuses, placental membranes, uterine fluids,

un-pasteurized milk or cheese. Raw vegetables and water

contaminated with excreta and reproductive fluids from infected

animals can also serve as a source of infection.

Persons of all ages are susceptible to brucellosis; however those at

greatest risk are in occupations which bring them in close contact with

diseased animals (i.e. abattoir workers, veterinarians, livestock

producers, and laboratory personnel). Most occupational cases

occur in men who are between 20-35 years of age.

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Literature review

Brucellosis is one of the most serious diseases of livestock, which

constitute a major impediment for livestock trade. Although brucellosis

has been eradicated in many developed countries in Europe, (Geering

et al. 1995), it remains an uncontrolled problem and its prevalence in

many developing countries is increasing (Refai 2002). Almost all

domestic species can be affected with brucellosis and cross-

transmission can occur between cattle, sheep, goats, camels and other

species. Infection rate in camels depends upon the infection rate in

primary host animals in contact with them as camels are not known to

be primary hosts for any of Brucella organisms (Agab et al. 1994).

Camel brucellosis was recoded to be caused by biotypes of B. abortus

and B. melitensis with 1.9–20% prevalence (Abbas and Agab, 2002). It

has been recorded in African and Asian countries where camels are

raised (Radwan et al. 1995; Musa and Shigidi 2001). The diagnostic

method known to produce the best results is by the isolation of

Brucella organisms; however, this method is unpractical to apply at a

large scale in control campaigns. Accordingly, the indirect diagnosis of

disease using serological tests is of choice. The standard Rose Bengal

plate test (RBPT) are the official tests currently used in the EU, which

has very high sensitivity but low specificity (Barroso et al. 2002; Muma

et al. 2008); however, a positive result is required to be confirmed by

some other more specific test like (I-ELISA) (Schelling et al. 2003).

During recent years, different indirect Enzyme- Linked Immunosorbent

Assays (I-ELISA) using smooth Lipopolysaccharides (S-LPS) as the

antigen have been reported to be at least as sensitive and specific as

the combination of both RB and CF tests for the diagnosis of brucellosis

in ruminants (Marín et al. 1998; Marín et al. 1999; Samartino et al.

1999). In many countries, control of brucellosis depends upon the test

and slaughter program combined with vaccination of the susceptible

population. In Somaliland this policy is not applicable. The regional

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brucellosis prevalence, will determine what to do first and which

measure should be followed for control of the disease. Little reports on

prevalence of brucellosis in camels in central and south Somalia have

been carried out (Baumann and Zessin 1992).

In East Africa a cross-sectional investigation was made into the

prevalence of brucellosis in camels in three arid and semi-arid camel

rearing regions of Ethiopia (Afar, Somali and Borena) between

November 2000 and April 2001. Where sera collected from 1442

accessible camels were screened with the Rose Bengal plate test

(RBPT), 82 (5.7%) of them reacted. The results of a complement

fixation test (CFT) on those sera that had given a positive reaction to

the screening test then indicated a 4.2% prevalence of brucellosis in

the tested camels.

In Somaliland there is a study which was carried out by

(Yasser M. Ghanem et al; 2008) last year whose purpose was to

investigate the prevalence and risk factors of camel brucellosis in

Northern Somalia (Somaliland). The study was carried out at three

main districts of camel-rearing regions of Somaliland (Awdal,

Maroodi jeex and Togdheer) in the period from July to November,

2008. A total of 1246 camel blood sera were randomly collected from

42 sporadic small scale camel herds. Two serological tests were used

to screen all serum samples, Rose Bengal Plate Test (RBPT) and

indirect ELISA (I-ELISA).The overall prevalence of camel brucellosis in

the districts under investigation was 3.9% by RBPT and 3.1% by (I-

ELISA).

The main purpose of this mini-thesis was to study the prevalence of

camel brucellosis in Sheikh District and specifically, to identify the

prevalence of camel brucellosis in Sheikh District, to find out the major

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clinical signs of camel brucellosis and to determine possible

intervention measures for controlling the disease.

MATERIALS AND METHODS

The study was conducted during the months of June and July 2009 in

Sheikh District, Sahel region, Somaliland.

Map of the Study area

Animals and data collection:

The 3 weeks of the study involved 12 herds of different sizes and a

total of 80 camel heads. They were of different health status, sex, age

9

Sheikh

Sheikh


and location in Sheikh District. The number of camel heads per herd

ranged between 5-10 heads. Camel herds were regularly examined

and random blood samples were collected during the period from June

to July 2009. The visited areas included: Laalays three herds (20

camels), Suqsade two herds (8 camels), sheikh one herd (6 camels),

Galoolay four herds (30 camels) and Kalasharka two herds (16). 31

camel herders were interviewed asking whether disease was present

or absent. Information on location, herd size, sex, age, history of

abortion, camel health and major clinical signs were obtained. The

genital organs were subjected to careful clinical examination by visual

observation and palpation.

Sampling and Sample processing:

In this study blood samples were randomly collected from 80 camels

of both sexes ranging in age from 6 months to 12 years. About 5 Ml of

blood was collected from the jugular vein of each selected animal,

using a syringe and vacutainer without anti coagulant and these blood

samples were allowed to clot overnight at room temperature.

The serum samples were separated manually and stored in the

refrigerator until testing. All sera were screened for antibodies against

Brucella by the Rose Bengal plate-agglutination test (RBPT) in STVS lab

and the positive serum samples were recorded. According to the

manufacturer, the sensitivity and specificity of RBPT are 89 and 97%,

respectively. The true prevalence of camel Brucellosis was estimated

by adjusting the apparent prevalence to the sensitivity and specificity

of the Rose Bengal Test using the formula of the true prevalence.

RESULTS

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In the locations that formed the study area, the largest numbers of

blood samples were collected from Galoolay, while the least numbers

of samples were collected from Sheikh town.

Collection of blood sample from a camel is very difficult compared to

other ruminants, because when collecting the sample, you need two to

three persons for restraining. In some places you can not find these

restrainers because the gender who is keeping the camels is a female,

since men go to the towns, though in Somali culture women are not

normally involved in couching and restraining camels. They are usually

involved with other ruminants such as sheep and goats.

Camel herders don’t pasteurize camel milk, because they believe if

they do so to camel milk, it will be useless and the quality of the milk

will be lowered.

Table1. Data collection of camel herders through interview

No. of people

interviewed

Presence Absence Unknown

31 10 (32%) 6 (19%) 15 (49%)

Figure 1. The percentage of camel herders’ response.

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31 elder farmers from different villages were interviewed about the

presence of camel brucellosis in the area, and if it was present the

major clinical signs they observe (Table 1).

The elders interviewed 10 (32%) told the researcher that they know

the disease, and the animals which suffer from the disease are those

rejected for export.

Camel owners also mentioned some clinical manifestations they

observe when the camels are infected with the disease, the clinical

signs included; loss of body condition, swollen of superficial lymph

nodes, protrusion at the vaginal area in female camel, infertility which

they called in their local language “Galgaal“. The owners who are

aware of the existence of the disease use a traditional remedy, by

inserting a piece of salt into the burst lymph node, that makes it shrink

and ultimately heal. The female camel vaginal protrusion brings about

excitement; it behaves like a male so that it has a tendency to mount

with other females in the presence of the male.

Table 2: Results of serological diagnosis of brucellosis by RBTP

Location No. of herd Male Female No. of Percentage %

12

10, 32%

6, 19%

15, 49%Presence

absence

Unkowon


sampled positive

Lalays 20 8 12 0 0

Suqsade 8 3 5 0 0

Sheikh 6 4 2 0 0

Galoolay 30 8 22 1 3.3

Kalasharka 16 7 9 1 6.3

Total 80 30 50 2 9.6

Out of the 80 camels whose sera were tested, 2 were positive by Rose

Bengal Test (RBT). The prevalence of camel brucellosis in Sheikh

District was (2.5%) Therefore, the true prevalence of camel brucellosis

in Sheikh District as adjusted to the RBT sensitivity and specificity is

2.87%. Results of serological diagnosis of brucellosis in camels at

different locations are summarized in (Table 2).

Discussion

Although Brucella organisms were not isolated in this study because of

inadequate facilities, and time constraint, but based on the results of

serological test of RBT, the prevalence of Brucella in examined herds,

which were 80 camels, was found to be 2.5%. This result is lower than

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that recorded by Yasser M. Ghanem et al; 2008 in Somaliland.

However, higher prevalence was also recorded in Egypt (Radwan et al.

1995; El-Boshy et al. 2009), Saudi Arabia (Radwan et al. 2006), and

Sudan (Yagoub et al. 1990).

Zoonotic diseases continue to present an important health hazard in

most parts of the world, particularly in developing countries. Infection

may develop in people who are frequently in contact with camel herds,

or who drink raw camel milk and its products, due to Lack of

knowledge of the disease transmission and it zoonotic nature, un

palatability of pasteurization camel milk among nomadic people, lack

of adequate sheep and goats Brucella control program, including

vaccination. This is what contributed to the presence of camel

brucellosis in the country. Unfortunately community of Sheikh District

does not pasteurize camel milk; and this may bring about the spread of

the disease.

The locality of camel rearing showed significant association with the

prevalence of Brucella infection. Kalashar village recorded the highest

prevalence (1 camel in 2 herds). This result was in agreement with that

recorded by Yasear M. G; 2008. The Kalashar village is situated at the

border of Sahel with Togdheer region; therefore, the uncontrollable

movement and contact with the infected animals may explain such

findings.

Yasear et al; 2008 attributed the effect of locality on Brucella infection

to husbandry, management practice, absence of Vet. Services, lack of

awareness, and uncontrolled movement of pastoralists from place to

another. This finding was also supported by Radostits et al; 2007 who

stated that the movement may worsen the epizootic situation of

Brucellosis in any locality, because the spread of infection is almost

always due to movement of infected animal to susceptible camel herd.

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This justifies why the disease is prevalent in the southern villages in

Sheikh Districts.

Camels are not known to be primary hosts for any of Brucella

organisms, but they are susceptible to both Brucella melitensis and

Brucella abortus. Infection rate in camels depends upon the infection

rate in primary hosts animals in contact with them (Agab et al. 1994).

This may further suggest the role of small ruminants in the occurrence

of camel brucellosis.

Prevention and control of animal brucellosis depends on the

establishment of an efficient national surveillance program and the

presence of an active reporting system (Anon, 1993).

Pastoralists in Sheikh District, just like other parts of Somaliland, have

difficulties in preventing and controlling diseases such as brucellosis on

their livestock. Since pastoralists are nomads, animals from different

owners with different species (sheep goats and camels) mix when

grazing, and watering. That makes it hard to control the disease.

There are some facts that must be taken into consideration while

trying to control this disease:

Brucellosis in camels seems to display less clinical sings than in other

ruminant animals, so the disease should be controlled by vaccination

in camels and primary hosts (sheep and goats)·

Due to the uncontrolled movements of different animals (camels,

sheep and goats) through the borders between Somaliland and

surrounding countries, it is recommended to vaccinate the animals in

Somaliland at regular intervals especially along the borders of the

country.

Adequate Brucella control programs in small ruminants may contribute

to the reduction in the prevalence of this disease in camels.

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Conclusion and recommendation

31 elder farmers from different villages were interviewed about the

presence of camel brucellosis in the area, the elders interviewed 10

(32%) told the researcher that they know the disease, and the animals

which suffer from the disease are those rejected for export. Camel

herders don’t pasteurize camel milk, because they believe if they do so

to camel milk, it will be useless and the quality of the milk will be

lowered. the clinical signs that owners mentioned included; loss of

body condition, swollen of superficial lymph nodes, protrusion at the

vaginal area in female camel, infertility which they called in their local

language “Galgaal“.

Out of the 80 camels whose sera were tested, 2 were positive by Rose

Bengal Test (RBT). The prevalence of camel brucellosis in Sheikh

District was (2.5%).

The results of the present investigation indicate that it is similar to the

other African countries, Brucella spp. exists within camel herds. This is

the first report that describes the prevalence of camel brucellosis in

Sheikh District. Therefore, frequent screening of the camel herds is

recommended to assess the status of the disease and to identify the

Brucella biotypes involved. Moreover, epidemiological studies need to

be done to explore the current status of the disease in other ruminants

and other animals to enable the public veterinary authorities to

construct concrete program for prevention of the disease within animal

herds in Sheikh and whole Somaliland or transmission of the disease

via animal trading to the other countries.

Reference:

1. Mustafa, M. and P. Nicoletti, 1993. Proceeding of the Workshop on Guidelines for a

Regional Brucellosis Control Program for the Middle East.

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2. FAO/WHO, 1986. Expert committee on brucellosis, Sixth Report. WHO Technical Report series, No. 740. WHO, Geneva.

3. Abbas, B., Agab, H., 2002. A review of camel brucellosis. Preventive Veterinary

Medicine, 55, 47–56. doi:10.1016/ S0167-5877(02)00055-7

4. Agab, H., Abbas, B., El-Jakack, H., Mamon, I. E., 1994. Firist report on the isolation

of Brucella abortus biovar 3 from camel (camelus dromedaries) in Sudan. Revue d

Elevage et de Medicine veterinaire des Pays Tropicaux, 47, 361– 363.

5. Baumann, M.p.O., Nuux, H.A., Zessin, K.H., 1990. Livestock disease survey central

rangeland of Somalia. Technical Report. Vol. III. Herd demographic and disease

survey data from herds of camels. CRDP-Veterinary Component, Mogadishu, Somalia

6. Geering, W. A., Forman, J. A., Nunn, M. J., 1995. Exotic Diseases of Animals.

Australian Government Publishing Service, Canberra, Australia, pp 301–306.

7. Musa, M. T., Shigidi, T. A., 2001. Brucellosis in camels in intensive Animal breeding

areas of Sudan. Implication in abortion and early-life infections. Revue d Elevage et

de Medicine veterinaire des Pays Tropicaux, 54, 11–15.

8. Radwan, A. I., Bekairi, S. I., Mukayel, A. A., Al-Bokmy, A. M., Prasad, P. V. S., Azar,

F. N., Coloyan, E. R., 1995. Control of Brucella melitensis infection in a large camel

herd in Saudi Arabia using antibiotherapy and vaccination with Rev. 1 vaccine. Revue

Scientifique et technique, 14, 719–732

9. Refai, M., 2002. Incidence and control of brucellosis in the Near East region.

Veterinary Microbiology, 90, 81–110. doi:10.1016/S0378-1135(02)00248-1

10. Yasser M. Ghanem et al; 2008

11. Agab, H., B. Abbas, H. El-Jakack and I.E. Mamon, 1994. Firist report on the

isolation of Brucella abortus biovar 3 from camel (camelus dromedaries) in Sudan.

Revue. Elev. Med. Vet. Pays. Trop., 47: 361- 363.

12. Anon, 1993. WHO Report of the MZCP Training Course on the Establishment of a

Human and Animal Brucellosis National Surveillance System, Heraklion, Greece.

13. Radostits, O.M., Gay, C.C., Hinchcliff, K.W., Constable, P.D., 2007. Brucellosis caused by Brucella abortus. In: Veterinary Medicine. 10th edn., Elsevier Saunders, London, UK.

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Sheikh Technical Veterinary School Mohamed's thesis about Seroprevalence of camel brucellosis in Sheikh district, 2009