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BRUCELLOSIS : Definition , Signs, Diagnosis ,Treatment and Control in Animals and Humans

Definition of the disease:

BRUCELLOSIS


    Storm abortion disease is a highly contagious disease caused by bacteria of the genus Brucella leading to drop in the  reproductive efficiency represented by abortion or the birth of weak offspring . In addition, the infection of the testes and the carrier vessel causes infertility in males in many animals of different species. .


Presence of the microbe within the Persistent "lifelong" infection is common as brucella is a intracellular parasite. The Brucella microbe can survive and reproduce within cells Phagocytic cells and tissues of the retinal system Reticulo endotheilial cells with the secretion of the microbes in the secretions of the reproductive system and suppositories.


Many types of brucellosis infect many species of animals widely. B. bortus affects cows and buffaloes, B.vis affects sheep, while B. melitensis affects both goats and sheep, and B.suis in pigs. Sometimes brucellosis affects 
dogs by C.Canis  and horses can be infected with brucella aborts and brucella swiss.

In human Brucella meltenis causes Maltese fever and Brucella Aborts cause brucellosis.


Food and Agriculture Organization, World Health and the Bureau of Epidemiology in Paris consider that brucellosis is the most common disease of public health in general. Brucella meletensis is the most virulent brucell spp to human being and can be infected by drinking goat's milk and contaminated sheep products .

Brucella in animals has very negative effects on the economy, especially in areas that adopt intensive production systems for cows in the world as a result of abortion and loss of embryos and deterioration of milk production and fertility, where periods increase between the milking season as well as between births. In sheep and goats economic losses result from lack of reproductive efficiency due to the infertility of rams and low milk production, which affects the growth of lambs and goats.

The disease is classified by the Office of International Epidemiology in Paris under the "B" list.




History and epidemiology of Brucella : 

Brucella Meletensis was first identified in Malta in 1887 by Bruce, while Brucella Abortes was identified in Denmark by Pange in 1897. The first recorded report of Brucella in Africa was in South Africa in 1906.


Brucella is spread in most developing countries, especially in the Mediterranean, West Asia and parts of Africa, including Egypt, as well as in Latin America. Many countries have made progress in their eradication programs and some countries have already eliminated the disease


Pathogen:
Brucella is a Gram-negative, non-moving, non-permeable, non-encapsulated, capsule-shaped, bony or round-to-bony form. These bacteria are relatively acid resistant as they resist the removal of color with weak acids during the dye with the modified zel-nelson, and the preserved folic acid Carbol color the bacteria in red on a blue background.


Brucella aerobic microorganisms need improved food media Enirched media for the first isolate, brucella grows well on 5-10% blood agar but other samples other than embryo and sarcophagus contents require an intestinal diet of serum agar such as Farrell's meda. Brucella abortus grow well  in the Biodiesel Type 2 as well as Brucella Ovis and Brucella canis are difficult to develop fastidious and grow slows down and need 5 - 10% carbon dioxide for the first insulation to begin growing and then normal airenough for grow . 
Brucella grows on special food media such as tryptose agar, brucella allbimiagar, liver infusion agar, blood agar and dixtrose serum agar at the center of the pH 6.8-6.6. 

Days of incubation :
 The developing colonies are smooth, convex, shiny and transparent surface The modern colonies are the color of the honey bees produced and are 1-2 mm in diameter, after which the incubation becomes larger and darker.

 The serotypes of Brucella  can be distinguished on certain bases such as their need for carbon dioxide, the production of hydrogen salphide (H2 S), the sensitivity to Azo dyes, the sensitivity of phage susceptibility, and agglutination in mono specific sera and some tests or other laboratory measurements.




There are currently 6 species of Brucella species that are almost identical with some differences in the shape and traits of plant, biochemical and serological tests, Brucella Aborts infecting cattle, including 9 species of biotypes and Brucella maltensis in goats and sheep and three species, And Brucella canis, which affects dogs, and other carnivores, and Brucella Neotama, which affects the desert wood rat.


Brucella abortes can survive for up to eight months in shade in aborted embryos and for 1-2 months in dry soils, 2-3 months in wet soil, 3 to 4 months in manure, as well as for eight months at 15 m in reservoirs. Manure and drainage in farms, but the microbe can resist the direct sun only for several hours.




Pasteurization kills the microbe and can not survive in yoghurt or any low-hydrogen dairy products. Brucella bacteria are also sensitive to chemical disinfectants such as carbolic acid with concentrations of 2-5%.




Sources and methods of transmission of the infection :


The brucellosis is found in the placenta, embryonic fluid, embryo, vaginal discharge, milk, semen, and urine. It is also found in arthritic sacs in infected horses in the case of polio or Fistulous withers . The largest source of infection is the contents of the uterus, fetus and chorionic membranes which contain large numbers of microbe contamination of the labia and tail and the back lists of the infected animal and the surrounding environment. The microbe is excreted for several days before the abortion and several weeks later. Some of the cows that were previously aborted produce the microbes from the uterus in the offspring that normally occur in later seasons. Most of the cows that have already given birth or those that give birth for the first time secrete the microbes in the sarcophagus and yogurt during the first month of digestion, but some of these cows may continue to secrete the microbe for a long time and possibly life span. Besides, the microbe is also secreted in urine, semen and manure for animals Infected.




Infection is mainly caused by ingestion of water or feed contaminated with the microbe or by the handling of infected or diseased or infected calves or calves or the external genitalia of infected cows following their abortion or birth. Infections may also occur in the skin, mucous membranes, conjunctiva, or inhaled eye. Infection through natural vaccination rarely occurs in cattle, although artificial insemination with sperm from infected birds often causes infection.


Calves may be infected within the womb during their embryonic life or by breastfeeding their infected mothers.



Infection occurs to humans by drinking  unpasteurized milk, or by drinking milk from unpasteurized milk or through mucous membranes, skin scratches and possibly by inhalation, especially in slaughterhouses and laboratories.




Most wild animals, rodents and blood-sucking insects such as ticks act as carriers and buffers of infection and therefore play a role in transmitting the disease




Symptoms of the disease:
* In cattle  :
Symptoms of the brucella




Cows and buffaloes are the natural hosts of Brucella Abortes and the rest of the animals that may be infected with the microbial are secondary hosts that rarely cause the infection of the cattle "Dead end host".


Infection course, products and accessories are controlled by the animal's age during the infection and the herd's immune status. Calves that have not yet been sexually transmitted are resistant to infection and systemic signs do not occur often. The incidence of abortion in herds of allergy is 30-70%.


Infected with a high rate of abortion A "storm of abortion" in infected cattle lasts one year or more and abortion occurs in the second half of pregnancy, especially during the last three months of pregnancy.


In the next and subsequent pregnancies, pregnancy is often completed and cows are normal but continue to produce the microbe from the uterus and in the milk. However, abortion may occur for the same cow for the second or third time in a few cases. In less severe cases, cows may give birth to dead calves or weak calves or perhaps just placental retention. In most cases, abortion is followed by inflammation of the uterus, which affects the fertility of these cows. Other symptoms of brucellosis at the herd level are increased incidence of placental retention and decreased milk production. In infected bulls, acute or chronic inflammation of the testicles, as well as inflammation of the spermatic cord and inflammation of the seminal vesicle, arthritis and hygroma, especially Carpal joint, may occur in male and female chronic infections.




Cows and buffaloes may be infected with brucella when there is direct mixing with infected goats or sheep, which may cause miscarriage, but in most cases the presence of the microbe is restricted to the supra mammary lymph nodes and the secretion of the microbial in the milk which may last for several months or years in some cases.


Infected cows and buffaloes with Brucella Swis is  rare and self-limiting brucellosis .




* In sheep and goats :
Symptoms of the brucella  in sheep &goats


Brucella meltensis in goats and sheep may cause miscarriage, placental retention, testicular inflammation and sperm. Abortion occurs in the later stages of pregnancy in sheep and in the fourth month of pregnancy in goats. Mastitis may be seen in goats. Lameness and arthritis are rare in sheep.




Brucella officiates only sheep without goats and may cause inflammation of the spermatic cord and testes and cause low fertility of rams. At the beginning of the infection the quality of the semen decreases only and then the lesions of the vessel and the testicles appear, which can be perceived by touching them by hand. The testes may have permanent atrophy. Placental inflammation and miscarriage may occur but is not common and systemic symptoms are also rare.




Brucella aborts and brucella swiss may sometimes infect sheep if they are infected from infected cows or pigs.




* In pigs


Swine infected with brucella swiss often has an abortion at any stage of pregnancy, or gives birth to a dead or weak child as temporary or permanent infertility. Testicular or temporary testitis may be seen on male pigs that may produce the microbe in the semen without symptoms and may be infertility is the only offer of infection. Lumbar and swollen joints may occur in either of the two sexes.




* In horses

Brucella abortis and sometimes brucella swiss may infect horses, causing Supraspinous bursa or Supra-atlantal bursa in what is known as fistulous withers, poll evil, respectively. The joint bag becomes filled with a clear, sticky liquid in a thick straw wall color, and this bag may explode and secondary infections occur. The infection is often accompanied by arthritis, intermittent limp, sternum, and fetlock. Prophylaxis associated with brucellosis is rare.




* In camels :

Brucella abortis and brucella malthensis can sometimes infect camels , which can result in miscarriage or the birth of a dead baby. The infection may be accompanied by tearful discharge, limited limp, and decreased appetite.




* In dogs


Brucella Canz affects dogs. Abortion or infertile births may lead to infertility. Abortion usually occurs in the last trimester of pregnancy and is followed by vaginal discharge for a long time.

Infections in dogs may be accompanied by inflammation of the lymph nodes, meningitis, testes and prostate.


Dogs may also have Brucella abortus , B.swiss or B.meletensis.


In Humans :




Infections without symptoms are common in humans, but in cases of symptoms, the incubation period ranges from 1 to 3 weeks or more, some of the symptoms are similar symptoms of influenza, which may include irregular fever with headache, weakness, fainting, sweat and stress with severe pain Limbs and back.




These symptoms end in healing within 2-4 weeks in many patients, while in some patients these symptoms recur in the form of seizures separated between 2-14 days and those patients with this wavy form heal completely within 3-12 months. Few patients have a chronic form characterized by persistent stress, depressive episodes and chronic arthritis. The return of the disease again after several months even after successful treatment may also occur.




Other symptoms may be less common. Complications may include arthritis, endocarditis, granulomatous hepatitis, biliary inflammation, gallbladder inflammation, uveitis, osteoarthritis, and rarely cerebral inflammation.


Diagnosis:
Brucella infection in general does not have a specific group of symptoms, but may be without symptoms for a long time so the diagnosis of the disease depends on the monitoring of antibodies to the microbial and then followed by bacteriological isolation and other tests.




Samples for laboratory diagnosis:


° For microbial implantation, samples of the contents of the fourth stomach (rennet), lung, spleen, aborted embryos, parts of embryonic membranes, vaginal discharge, milk, semen, as well as arthritis and hygroma fluids.


After slaughter or superiority, samples are collected from the tissues of the hernias, upper lymph nodes and those related to the reproductive system, along with other samples of the spleen and pregnant uterus.


"The tissue samples should be carefully collected for not being" Aseptically "contaminated in a few sterile phosphate buffered saline solution.




° Serological tests: Blood samples should be collected for serum suppression along with samples of milk and samples of whey or whey as well as semen.


Direct microscopic examination of vaginal secretions, lactation, or vaginal swabs on the food media has the advantage of directly monitoring the microbe, thus reducing the likelihood of false positive results, but this procedure is costly and time-consuming.


Direct examination without transplantation may not detect the few numbers of the microbes that may be present in dairy products.

Serological tests: 
There is no single serological test that meets all the requirements of accurate diagnosis. Some experiments are not useful with some types of hosts and some experiments are not suitable for some types of microbes. Therefore, the tests are conducted by a set of tests for each of its own applications.


* Brucella milk ring test (MRT): A sensitive, inexpensive and valuable test in the milk samples collected in young herds.


- Agglutination antibodies are caused by the agglutination of the antibodies associated with the fatty granules, so that this complex complex rises to the top to be a layer of colored hardness on the surface.


- In this test, a drop of the stained microbial antigen is placed on 1 ml of milk collected after it is poured into the plastic stacking tube and incubated at 37 ° C for one hour. The result is evaluated by the color of the cream layer as well as milk as follows:

 The highly positive sample (+++) is a very creamy layer of cream while milk or whey is completely white.

The positive sample (++) is a very creamy layer of cream while milk or whey is limited in blue.

 The weak positive sample (+) is a very creamy layer of cream while the milk or its serum is also clearly blue.

 Recycled sample (±) The cream layer and yogurt have the same color.

 The negative sample (-) is the colorless cream layer while the milk is very blue.




* Stacking tests for blood serum:


Common tests used in diagnosis include: Rapid plate Agglutination test and Standard tube Agglutination test

- Although stacking tests can monitor antibodies in milk, whey and vaginal secretions, they are faulty to monitor specific and non-specific antibodies arising from natural or immunization-related infections and are at the back of trials that reach diagnostic levels during incubation, post-abortion or In addition, they often give false negative results when examining chronic conditions due to the low level of antibodies involved while other tests give positive results.


- The SAT test is sometimes used as an additional or supplementary test and is particularly important in measuring the most common IgM antibodies and remaining after vaccination with 19.


- The rapid digestion test with "RPAT" is fast and is not affected by Prozone Phenomena but is less sensitive than the SAT test.

* Tests based on buffered antigen antigen (BBAT).

It is the most commonly used test and is based on the idea that IgM antibodies are low in the middle of a low hydrogen mass. These tests include the Card test, the Rose bengal test (RBPT), and the Buffered plate agglutination test "BPAT".

Rose  Bengal test: It is characterized as a simple and rapid agglutination test and is used to scan the herds by examining the serum on a large scale.


The CFT is a very sensitive and specific test and is one of the most important stress tests, but it is difficult to do.

ELISA test: The ELISA test was recently used to monitor antibody antibodies in the milk and serum as it was used to monitor the microbial antigens in vaginal secretions.

Other tests:

Other less commonly used tests such as:

- Refinol test of the sediment Rivanol precipitetin test. Indirect hemolysis test as a supplementary or supplemental test for supplemental stabilization in the final stages of eradication programs. A fluorescent fluorescence test was also developed,


Swaps :

The commonly used ring milk test is used for the examination of milking herds, while the bronchial test on serum is commonly used to survey non-milking herds in markets and slaughterhouses. The tubular stacking test may also be used

In sheep, brucellosis can be diagnosed in many ways, including touching the external genitalia of rams, the presence of brucellosis, as well as neutral cells in semen swabs, and the need for repeated sampling to monitor the clinical conditions in particular. The serological tests that can be used are the bronchial test, The complementary stabilization test and the fluorescent fluorescence test and the gel diffusion tests.

o In sheep and goats: Brucella maltensis infection can be diagnosed from the presence of this microbial in the fourth stomach of aborted fetuses or in vaginal secretions and in swabs taken from the seminal cord, as well as serological tests such as the Bengal Rose test, the supplemental stabilization test and ELISA test. The test of the skin sensitivity of Procillin can be used as a test on unapproved herds. The combined ring milk test is not used in small ruminants.

In pigs: Brucella swiss infection can be diagnosed with bacteriology as well as serology using the supplemental stabilization test and ELISA test.

In camels : The Bengal Rose test and the supplemental installation test are the two most commonly used.


• Comparative diagnosis: abortion of multiple problems and a variety of causes, including infectious causes, including non-communicable and therefore when faced with the problem of abortion in a herd or in a certain area, the investigation of the cause and how to deal with it must be done according to a set of criteria include:

 Examination of the status and herd history, which includes the production system, nutrition and fertility indicators, including abortion rates and placental retention rates.

 Determination of the age of the fetus with its examination and anatomy and examination of the placenta to indicate the presence of inflammation or not.

 Screening of the aborted cow Clinical examination to exclude other pathologies such as salmonella infection, summer mastitis or tick fever.

Blood samples should be taken for serological tests for brucellosis and leptospira. Vaginal secretions, as well as the contents of the fourth fetus, should be examined immediately at the first opportunity to search for trichomonas or for transplantation of Brucella abortus, Campylobacter Fetus, Tricomans, Listeria and fungi. The urine of the lipospera microbes.

Treatment of Brucellosis  :

Treatment of brucellosis in cattle is neither effective nor practical due to the hiding of the microbes within the lymph nodes and the tissues of the inguinal and genital organs. The drugs are not able to penetrate the walls of the cell walls, and some antibiotics may cause some "L.transformations" of Brucella Abortes, which prevents them from being monitored by serology, thus exacerbating the phenomenon of the animals carrying the disease.


There is no practical treatment for treating Brucella-infected pigs as well.

Antibiotics may lead to the elimination of brucellosis in infected rams but their fertility remains low.


Antibiotic therapy for a long time is sometimes successful with Brucella Canes in dogs.


Fistulous withers or pollen may need to be surgically removed.


Immunity:

Animals that have been infected or vaccinated have a relative immunity. Adult and adult animals, but not a public person, have some degree of immunity as they do not show any symptoms of the disease.   
Treatment Of Brucella


The animals that have aborted have relative immunity that often does not abort once again. Animals that have been infected or grafted with the 19-year-old vaccine remain positive for the blood collection test or other stacking tests for a long time.

Serums of infected animals contain a high proportion of antibiotic species, IgA, IgG2, IgG1, IgM and "Isotypes antibodies". After ingestion of cattle 19, the IgM type begins to emerge after 5 days, the most dominant and survival type, reaching its highest level after 13 days. IgG1 antibodies may appear with IgM and reach its highest level in 28-42 days as they begin to decline thereafter.

Most chronic infections remain positive for CFT, but a significant proportion of them are negative for the slow tubular stacking test as the antibodies lining the ligaments tend to weaken and end within several months.

Calves that feed positive mothers are infected by antibodies and the half-life of these antibodies is about 22 days.


Methods of control  of the disease:
Policies for controlling or eradicating brucellosis in cattle will vary depending on the situation in each case. Outlines for control of brucellosis in cattle and its eventual eradication are vaccination, testing policy and the slaughter of positive animals, as well as preventing the sale and movement of infected animals.


In the country and areas with high infection rates, the phased goal is to reduce cases of infection through vaccination with the application of health measures well. In this situation, large-scale vaccination is used as a first stage control of the disease before applying the examination stage and slaughter positive cases. Vaccination reduces the risk of miscarriage and the removal of the microbes. Vaccination can reduce the number of infected cases in a herd by more than 90% if applied for five years.

Vaccine strain 19:


The strain 19 is a low-fermented, high-immunogenic animal.

Vaccination of oral wheels between 4-8 months with the 19-year-old vaccine provides relative immunity for 16-18 months. A limited proportion of grafted animals produce special antibodies, the SAA, which may persist until adulthood, which may cause confusion in the process of serological diagnosis. In order to reduce these problems, calves were vaccinated at much lower doses.


Vaccination of large animals is not allowed and is authorized only for some herds in the face of epidemics to reduce the abortion storm.


Vaccine vaccine 19 is low ferocity for livestock and if there are some systemic reactions may occur rarely in the wheels or in adult animals.


Vaccine vaccine 19 is not beneficial for bulls and may even cause testicular inflammation, and with misuse it may have an effect on public health for veterinarians dealing with animals.

Immunization should not be stopped with the 19-year-old vaccine unless the infection rate falls below 0.2%

Inactivated strain 45/20 adjuvant vaccine:

A vaccine for all ages but does not provide the immunity provided by the 19-year-old vaccine in animals younger than 9 months of age.

In animals older than 6 months it is recommended to inject two consecutive doses between 6-12 weeks.

This vaccine is defective because it interferes with the highly complementary stabilization test but interferes with the tubular stacking test to a limited extent.

Vaccine vaccine RB 51 "Strain RB 51":




Vaccine is a hardened, live-tested vaccine that can be used to protect against infection and against abortion, as is the case with anthrax 19, but it does not produce antibodies that can be monitored by the serological tests used to help identify grafted animals.




It is recommended to vaccinate the oral cavity greater than 4 months, but may cause placental inflammation if given to the animals of a common man 6 months, which causes the birth of premature babies or mature Premature birth and prefer to vaccinate the animals at the age of 4-7 months as in the vaccine.




Eradication of disease in a region or country begins when the disease is reduced to 0.2% or less, and the procedures for the eradication of herds require the detection and slaughter of positive cases accompanied by the vaccination of the wheels. This system is expensive and the national economy of some countries may not be able to afford it.




All calves in the infected herds should be considered future contaminants, since calves with the latent and negative impact of the serological tests remain as early as mid-gestation or later in their first pregnancy in the two-year breakdown syndrome.




The ongoing comprehensive screening of blood samples as well as bacteriological examination in infected herds should take place every 2-3 months




In the combined ring milk test, milk from the negative samples must be re-examined regularly at frequent intervals.




All animals positive for serological tests or bacteriological tests are considered to be infected and must be marked with permanent signs.




It is very important to reduce the spread of infection, especially the times of epidemics. Before and after birth, cows should be isolated and aborted cows should be isolated immediately with the burning of aborted embryos and infestations as well as the bedding contaminated with excretions. 3 weeks.




The herd is free of infection after 2-3 consecutive negative tests, and the infection-free herd should be maintained in this situation where the animals added to the herd should be free from infection and must be tested before being introduced into the herd with / Only grafted.
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