Brucellosis in a returned traveler and his wife: probable person-to-person transmission of Brucella melitensis

Bovine brucellosis - a comprehensive review

Brucellosis is a zoonotic disease of great animal welfare and economic implications worldwide known since ancient times. The emergence of brucellosis in new areas as well as transmission of brucellosis from wild and domestic animals is of great significance in terms of new epidemiological dimensions. Brucellosis poses a major public health threat by the consumption of non-pasteurized milk and milk products produced by unhygienic dairy farms in endemic areas. Regular and meticulous surveillance is essentially required to determine the true picture of brucellosis especially in areas with continuous high prevalence. Additionally, international migration of humans, animals and trade of animal products has created a challenge for disease spread and diagnosis in non-endemic areas. Isolation and identification remain the gold standard test, which requires expertise. The advancement in diagnostic strategies coupled with screening of newly introduced animals is warranted to control the disease. Of note, the diagnostic value of miRNAs for appropriate detection of B. abortus infection has been shown. The most widely used vaccine strains to protect against Brucella infection and related abortions in cattle are strain 19 and RB51. Moreover, it is very important to note that no vaccine, which is highly protective, safe and effective is available either for bovines or human beings. Research results encourage the use of bacteriophage lysates in treatment of bovine brucellosis. One Health approach can aid in control of this disease, both in animals and man.

Evaluation of the relationship between IL-12, IL-13 and TNF-α gene polymorphisms with the susceptibility to brucellosis: a case control study

Background

The cytokine gene polymorphism is important for the genetic susceptibility of infectious diseases. The aim of the present study was to investigate the relationship between TNF-α, IL-12, and IL-13 gene polymorphisms and predisposition to brucellosis.

Methods

In this study, 107 patients with brucellosis and 107 healthy individuals were evaluated. The SNPs of TNF-α)- 238 G/A) and IL-12 (+ 1188 A/C) were done by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and IL-13 genotyping at positions − 1512 (A/C) and − 1112 (C/T) were analysis by restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) methods. IL-12, IL-13 and TNF-α serum levels were measured by a sandwich enzyme-linked immunosorbent assay (ELISA).

Results

IL-13 (−1512A/C) was associated with Brucellosis risk in dominant model (OR (95% CI) = 2.17 (1.02–4.62)), P-value = 0.041. However, there was no difference in allele and genotype frequencies of TNF-α)- 238 G/A), IL-12 (+ 1188 A/C) and IL-13 [− 1512 (A/C) and − 1112 (C/T)] between patients and controls. Serum levels of IL-12 and TNF-α were significantly more frequent in the patients than in the control groups.

Conclusions

The IL-13 gene polymorphism can be used as a biomarker for detecting susceptibility to Brucella disease.

Mucosal bacterial dissemination in a rhesus macaque model of experimental brucellosis

Animals were experimentally infected with Brucella melitensis via aerosol. B. melitensis was cultured from the saliva and vaginal vault of infected animals, corresponding to bacterial dissemination in other target tissues. This is the first report of bacterial dissemination to these mucosal surfaces in a non-human primate model of brucellosis.

Review of brucellosis in Nepal

Brucellosis is an abortifacient zoonotic disease that remains prominent in third world countries like Nepal. Brucellosis poses a public health concern, because its incidence in livestock can present substantial economic and health burdens for herders and health professionals. Several cases of bovine and human brucellosis have been reported and the prevalence is higher among livestock than among humans in Nepal. Lack of awareness, unhealthy food habit, traditional husbandry practices, and a lack of surveillance and immunization have been the major factors in maintaining a vicious cycle of propagation of the disease in human and animals. The aim of this paper is to evaluate the current status of the disease, the mechanism of infection, and pathogenesis, its zoonotic potential, diagnostic advances, treatment regimens, and the preventive measures that can be adopted in managing human brucellosis in under-developed countries such as Nepal.

Review of Brucellosis in Nepal

OBJECTIVES

The aim of this paper is to evaluate the current status of the disease, the mechanism of infection, and pathogenesis, its zoonotic potential, diagnostic advances, treatment regimens, and the preventive measures that can be adopted in managing human brucellosis in under-developed countries such as Nepal.

METHODS

We performed a systematic review of all the available literture through Google Scholar, PubMed, Gideon Informatics, World Health Organization and other legitimate sources. Other secondary informations were collected from the government agencies such as department of livestock services and Ministry of Health. The obtained information was then re-analysed and summarized.

RESULTS

Few publications have addressed brucellosis in Nepal and most of those publications have focused on bovine brucellosis with sparse information available on brucellosis in humans and small ruminants. Brucella abortus is the most predominant causative agent followed by B. suis. B. abortus is predominant in cattle accounting for a substantial portion of bovine abortion in the country. Lack of awareness, unhealthy food habit, traditional husbandry practices, and a lack of surveillance and immunization have been the major factors in maintaining a vicious cycle of propagation of the disease in human and animals. Unfortunately, nothing has been done to identify the species of Brucella at the biovar level.

CONCLUSIONS

Although brucellosis has been reported to be endemic in Nepal, neither the distribution nor the economic and public health impact of this disease is well characterized. Robust and well-designed nationwide survey is warranted to assess the prevalence and distribution of disease in livestock and humans. Such data would facilitate the design of appropriate control programmes.

Brucellosis in Nepal - A Potential Threat to Public Health Professionals

Brucellosis is a prominent zoonotic disease affecting humans and animals which with the lack of proper diagnosis and treatment remains dangerous in third world countries like Nepal. Currently, Brucellosis poses a public health concern, whose incidences among entire herds of animals can present substantial economic and health burdens for herders and health professionals. Additionally, factors such as close contact with animals, poor animal husbandry, and unhygienic feeding habits can exacerbate the spread of Brucella and related zoonotic agents. In Nepal, serious cases of bovine and even human brucellosis have been reported, although the topic is yet to be extensively reviewed. This paper evaluates the literatures on human and animal brucellosis in Nepal and other countries, with an emphasis on the impact of Brucella outbreaks on public health professionals. Herein, we summarize the current status of the disease, the mechanism of infection, pathogenesis, zoonotic potential, diagnostic advances, treatment regimens, and the preventive measures that can be adopted in managing human brucellosis in under-developed countries such as Nepal.

Imported brucellosis: A case series and literature review

BACKGROUND

Brucellosis is one of the main neglected zoonotic diseases. Several factors may contribute to the epidemiology of brucellosis. Imported cases, mainly in travellers but also in recently arrived immigrants, and cases associated with imported products, appear to be infrequently reported.

METHODS

Cases of brucellosis diagnosed at a referral unit for imported diseases in Europe were described and a review of the literature on imported cases and cases associated with contaminated imported products was performed.

RESULTS

Most imported cases were associated with traditional risk factors such as travel/consumption of unpasteurized dairy products in endemic countries. Cases associated with importation of food products or infected animals also occurred. Although a lower disease incidence of brucellosis has been reported in developed countries, a higher incidence may still occur in specific populations, as illustrated by cases in Hispanic patients in the USA and in Turkish immigrants in Germany. Imported brucellosis appears to present with similar protean manifestations and both classical and infrequent modes of acquisition are described, leading on occasions to mis-diagnoses and diagnostic delays.

CONCLUSIONS

Importation of Brucella spp. especially into non-endemic areas, or areas which have achieved recent control of both animal and human brucellosis, may have public health repercussions and timely recognition is essential.

The Prevalence of Brucellosis in Cattle, Goats and Humans in Rural Uganda: A Comparative Study

A cross-sectional study was conducted to determine the presence of brucellosis in cattle, goats and humans in farms from south-western Uganda and identify risk factors associated with brucellosis in these three host groups. Data and serum samples were collected from 768 cattle, 315 goats and 236 humans, with 635 samples of bovine milk, from 70 farms in two different study areas in south-western Uganda. Sera from livestock were tested with the Rose Bengal Plate test, using B. abortus and B. melitensis antigens, and human sera were tested with a commercial IgG/IgM lateral flow assay. Milk samples were tested using the OIE-approved milk ring test. Screening tests for brucellosis were positive in 14% of cattle serum, 29% of bovine milk, 17% of goat serum and 11% of human serum samples. There were significant differences in the test prevalence of brucellosis by study site, with levels higher in the study area near Lake Mburo National Park than in the study area near Queen Elizabeth National Park. Multivariable regression models identified risk factors associated with increasing test positivity at the individual and farm levels for cattle, goats and humans. Positive associations were seen between increasing seropositivity of brucellosis in goats, cattle and humans. Results of multivariable analyses suggest that improvements in farm biosecurity and hygiene may reduce the risk of brucellosis on the farm and suggest a role for ticks in bovine brucellosis. Although cattle are the focus of brucellosis control in Uganda, the significant associations between seropositivity in humans and seropositivity in goats suggest that brucellosis in goats may be an important contributor to the epidemiology of the disease on the farm.

Brucella evasion of adaptive immunity

The complex immune system of mammals is the result of evolutionary forces that include battles against pathogens, as sensing and defeating intruders is a prerequisite to host survival. On the other hand, microorganisms have evolved multiple mechanisms to evade both arms of immunity: the innate and the adaptive immune systems. The successful pathogenic intracellular bacterium Brucella is not an exception to the rule: Brucella displays mechanisms that allow evasion of immune surveillance in order to establish persistent infections in mammals. In this review, we highlight some key mechanisms that pathogenic Brucella use to evade the adaptive immune system.

Serological evidence of brucellosis in goats in kaduna north senatorial district of kaduna state, Nigeria

A cross-sectional study was carried out to determine the current status of Brucella antibodies in goats in Kaduna North Senatorial District of Kaduna State, Nigeria. A total of 442 serum samples (31 bucks and 411 does) were screened using Rose Bengal plate test (RBPT), serum agglutination test with ethylene diaminetetraacetic acid (SAT-EDTA), and lateral flow assay (LFA). Results. The prevalence of Brucella antibodies was found to be 25.8%, 11.1%, and 2.5% using RBPT, SAT-EDTA, and LFA, respectively. The prevalence in bucks was 32.3%, 3.2%, and 0.0% and 17.5%, 12.4%, and 3.9% in does using RBPT, SAT-EDTA, and LFA, respectively. The prevalence rates for goats less than one year of age using the tests were 1.5%, 0.0%, and 0.0%. While for those within the age bracket of one to three years, the rates were 19.4%, 10.5%, and 3.5%, respectively. The corresponding values for goats above 3 years of age were 34.2%, 15.2%, and 1.8%, respectively. The prevalence of brucellosis in goats in the study area is high which poses a threat to the development of the livestock industry and is of important zoonotic implications in Nigeria.

Time series analysis of human and bovine brucellosis in South Korea from 2005 to 2010

Brucellosis is considered to be one of the most important zoonotic diseases in the world, affecting underdeveloped and developing countries. The primary purpose of brucellosis control is to prevent the spread of disease from animals (typically ruminants) to humans. The main objective of this study was to retrospectively develop an appropriate time series model for cattle-to-human transmission in South Korea using data from independent national surveillance systems. Monthly case counts for cattle and people as well as national population data were available for 2005-2010. The temporal relationship was evaluated using an autoregressive integrated moving average with exogenous input (ARIMAX) model [notated as ARIMA(p, d, q)-AR(p)] and a negative binomial regression (NBR) model. Human incidence rate was highly correlated to cattle incidence rate in the same month and the previous month (both r=0.82). In the final models, ARIMA (0, 1, 1)-AR (0, 1) was determined as the best fit with 191.5% error in the validation phase, whereas the best NBR model including lags (0, 1 months) for the cattle incidence rate yielded a 131.9% error in the validation phase. Error (MAPE) rates were high due to small absolute human case numbers (typically less than 10 per month in the validation phase). The NBR model however was able to demonstrate a marked reduction in human case immediately following a hypothetical marked reduction in cattle cases, and may be better for public health decision making.

Brucellosis: a re-emerging zoonosis

Brucellosis, especially caused by Brucella melitensis, remains one of the most common zoonotic diseases worldwide with more than 500,000 human cases reported annually. The bacterial pathogen is classified by the CDC as a category (B) pathogen that has potential for development as a bio-weapon. Brucella spp. are considered as the most common laboratory-acquired pathogens. The geographical distribution of brucellosis is constantly changing with new foci emerging or re-emerging. The disease occurs worldwide in both animals and humans, except in those countries where bovine brucellosis has been eradicated. The worldwide economic losses due to brucellosis are extensive not only in animal production but also in human health. Although a number of successful vaccines are being used for immunization of animals, no satisfactory vaccine against human brucellosis is available. When the incidence of brucellosis is controlled in the animal reservoirs, there is a corresponding and significant decline in the incidence in humans.