Consumption Of Unpasteurized Milk Products Research Articles

First Expert Elicitation of Knowledge on Possible Drivers of Observed Increasing Human Cases of Tick-Borne Encephalitis in Europe

Tick-borne encephalitis (TBE) is a viral disease endemic in Eurasia. The virus is mainly transmitted to humans via ticks and occasionally via the consumption of unpasteurized milk products. The European Centre for Disease Prevention and Control reported an increase in TBE incidence over the past years in Europe as well as the emergence of the disease in new areas. To better understand this phenomenon, we investigated the drivers of TBE emergence and increase in incidence in humans through an expert knowledge elicitation. We listed 59 possible drivers grouped in eight domains and elicited forty European experts to: (i) allocate a score per driver, (ii) weight this score within each domain, and (iii) weight the different domains and attribute an uncertainty level per domain. An overall weighted score per driver was calculated, and drivers with comparable scores were grouped into three terminal nodes using a regression tree analysis. The drivers with the highest scores were: (i) changes in human behavior/activities; (ii) changes in eating habits or consumer demand; (iii) changes in the landscape; (iv) influence of humidity on the survival and transmission of the pathogen; (v) difficulty to control reservoir(s) and/or vector(s); (vi) influence of temperature on virus survival and transmission; (vii) number of wildlife compartments/groups acting as reservoirs or amplifying hosts; (viii) increase of autochthonous wild mammals; and (ix) number of tick species vectors and their distribution. Our results support researchers in prioritizing studies targeting the most relevant drivers of emergence and increasing TBE incidence.

Development of a Rapid and Sensitive Colorimetric Loop-Mediated Isothermal Amplification Assay: A Novel Technology for the Detection of Coxiella burnetii From Minimally Processed Clinical Samples.

Q fever is an important zoonotic disease caused by the bacterium Coxiella burnetii. The agent is considered as a potential agent for bioterrorism because of its low infectious dose, aerial route of transmission, resistance to drying, and many commonly used disinfectants. Humans are largely infected by the inhalation of aerosols that are contaminated with parturition products of infected animals as well as by the consumption of unpasteurized milk products. Thus, rapid and accurate detection of C. burnetii in shedders, especially those that are asymptomatic, is important for early warning, which allows controlling its spread among animals and animal-to-human transmission. In the present study, a colorimetric loop-mediated isothermal amplification (LAMP) assay was developed to confirm the presence of IS1111a gene of C. burnetii in sheep vaginal swabs. The sensitivity of this assay was found to be very comparable to the quantitative PCR (qPCR) assay, which could detect three copies of the gene, which corresponds to a single cell of C. burnetii. The applicability of the colorimetric LAMP assay in the disease diagnosis was assessed by evaluating 145 vaginal swab samples collected from the sheep breeding farms with a history of stillbirth and repeated abortions. Compared to qPCR, colorimetric LAMP had a sensitivity of 93.75% (CI, 69.77–99.84%) and specificity of 100% (CI, 97.20–100%), with a positive (PPV) and negative predictive value (NPV) of 100 and 99.24%, respectively. A very high level of agreement was observed between both colorimetric LAMP and reference qPCR assay. The colorimetric LAMP assay reported here is a rapid and simple test without extensive sample preparation and has a short turnaround time of <45 min. To the best of our understanding, it is the very first study describing the use of colorimetric LAMP assay that detects C. burnetii in vaginal swab samples with minimal sample processing for DNA extraction.

Coxiella burnetii Infection in Milk of Cattle and The Risk of Human Infection in Menoufia Governorate.

ABSTRACT:Q fever is a major anthropozoonotic disease infecting animals and man all over the world except in the Antarctic and New Zealand. This study aimed to highlight the public health significance of Q fever among dairy cattle and the potential role of raw milk products in transmitting the infection to humans in Menoufia governorate. A total of 60 raw milk samples were collected from 60 apparently healthy Baladi dairy cows of different ages from 3 localities in Menoufia governorate (20 from Shebein El-Kom, 20 from Tala and 20 from Menouf) and examined for presence of C. burnetii DNA by PCR. Results revealed that 25% (15/60) of milk samples had C. burnetii DNA. No significant association was revealed between PCR positivity and the cattle age or selected localities. Moreover, the current study involved estimation of seroprevalence of anti-C. burnetii phase II IgG antibodies by ELISA test among 184 attendants of Shebein El Kom fever and chest hospitals in Menoufia governorate in relation to the habit of consumption of unpasteurized milk products. 41.85% (77/184) of the examined individuals were positive for phase II IgG antibodies. A highly significant association was found between increased seroprevalence and the pattern of consumption of unpasteurized milk products per week since the patients with the habit of usual consumption (5-7 days/week) had the highest seroprevalence rate 56.10% (23/41) versus 47.14% (33/70) and 28.77% (21/73) among those with moderate (2-4 days/week) and rare (0-1 days/week) patterns of consumption, respectively. In conclusion, presence of C. burnetii DNA in milk of cattle and C. burnetii phase II IgG in contact human being could confirm the role of food from animal origin in transmission of Q fever to man.

Human brucellosis: sero-prevalence and associated risk factors in agro-pastoral communities of Kiboga District, Central Uganda.

BackgroundBrucellosis remains a neglected zoonotic disease among agro-pastoral communities where unprocessed milk and milk products are consumed. A cross-sectional study was carried out in Kiboga district to determine the seroprevalence and risk factors associated with human brucellosis in communities where livestock rearing in a common practice.MethodsA total of 235 participants were involved in the study. Blood samples from the participants were collected and screened for Brucella using Serum Agglutination Test and Rose Bengal Plate Test. A questionnaire was used to collect data on socio-demographic characteristics and human brucellosis related risk factors.ResultsHuman Brucella seroprevalence was at 17.0 % (n = 235). The prevalence was highest among males (20.5 %, n = 78) and the elderly - above 60 years (22.2 %, n = 18). Residence in rural areas (OR 3.16, 95 % CI: 1.16–8.56), consuming locally processed milk products (OR 2.54, 95 % CI: 1.12–5.78) and being single (OR 2.44, 95 % CI: 1.05–5.68), were associated with increased risk of brucellosis.DiscussionHuman brucellosis seroprevalence was high at 17 %, this was parallel with animal brucellosis prevalence that has been reported to range from 10.2 % to 25.7 % in cattle in the region. The participants were from communities known to habitually consume raw milk and milk products, know to process milk products using bare hands which are major risk factors for brucellosis in humans. This also explains why consumption of unpasteurized milk products was associated with the occurrence of brucellosis in study area. This strengthened the argument that humans get infected through consumption of contaminated animal products as reported in other earlier studies. Males and elderly being more affected because of traditional roles of these groups they play in livestock care and management. The single were also to be more associated to brucellosis, due to the fact that this group consume milk and milk products more as it is readily available in the informal markets as highly nutritious fast foods in this community as also observed in USA.ConclusionsBrucellosis is highly prevalent in Kiboga district, and therefore, an important public health problem. The transmission risk was aggravated by consumption of unpasteurized milk products, residing in rural settings and being single. There is a need to initiate screening, treat infected humans early, and educate the public about risk factors and appropriate preventive measures of brucellosis.

Toxoplasma gondii Infection in Kyrgyzstan: Seroprevalence, Risk Factor Analysis, and Estimate of Congenital and AIDS-Related Toxoplasmosis

BackgroundHIV-prevalence, as well as incidence of zoonotic parasitic diseases like cystic echinococcosis, has increased in the Kyrgyz Republic due to fundamental socio-economic changes after the breakdown of the Soviet Union. The possible impact on morbidity and mortality caused by Toxoplasma gondii infection in congenital toxoplasmosis or as an opportunistic infection in the emerging AIDS pandemic has not been reported from Kyrgyzstan.Methodology/Principal FindingsWe screened 1,061 rural and 899 urban people to determine the seroprevalence of T. gondii infection in 2 representative but epidemiologically distinct populations in Kyrgyzstan. The rural population was from a typical agricultural district where sheep husbandry is a major occupation. The urban population was selected in collaboration with several diagnostic laboratories in Bishkek, the largest city in Kyrgyzstan. We designed a questionnaire that was used on all rural subjects so a risk-factor analysis could be undertaken. The samples from the urban population were anonymous and only data with regard to age and gender was available. Estimates of putative cases of congenital and AIDS-related toxoplasmosis in the whole country were made from the results of the serology. Specific antibodies (IgG) against Triton X-100 extracted antigens of T. gondii tachyzoites from in vitro cultures were determined by ELISA. Overall seroprevalence of infection with T. gondii in people living in rural vs. urban areas was 6.2% (95%CI: 4.8–7.8) (adjusted seroprevalence based on census figures 5.1%, 95% CI 3.9–6.5), and 19.0% (95%CI: 16.5–21.7) (adjusted 16.4%, 95% CI 14.1–19.3), respectively, without significant gender-specific differences. The seroprevalence increased with age. Independently low social status increased the risk of Toxoplasma seropositivity while increasing numbers of sheep owned decreased the risk of seropositivity. Water supply, consumption of unpasteurized milk products or undercooked meat, as well as cat ownership, had no significant influence on the risk for seropositivity.ConclusionsWe present a first seroprevalence analysis for human T. gondii infection in the Kyrgyz Republic. Based on these data we estimate that 173 (95% CI 136–216) Kyrgyz children will be born annually to mothers who seroconverted to toxoplasmosis during pregnancy. In addition, between 350 and 1,000 HIV-infected persons are currently estimated to be seropositive for toxoplasmosis. Taken together, this suggests a substantial impact of congenital and AIDS-related symptomatic toxoplasmosis on morbidity and mortality in Kyrgyzstan.

A multicenter retrospective study of childhood brucellosis in Chicago, Illinois from 1986 to 2008

To determine risk factors in children for the acquisition of Brucella, clinical presentation, treatment, and disease outcomes. A retrospective multicenter chart review was undertaken of children identified with brucellosis from 1986 to 2008 at three tertiary care centers in Chicago, Illinois, USA. The charts were reviewed for data regarding risk factors for acquisition, clinical presentation, and outcomes. Twenty-one charts were available for review. The median age was 6.5 years (range 2-14 years); 62% were female. Ethnic background was 67% Hispanic and 24% Arabic. Risk factors included travel to an endemic area (86%), particularly Mexico, and consumption of unpasteurized milk products (76%). Common findings included fever (95%), bacteremia (86%), elevated liver transaminases (80%), constitutional symptoms (76%), splenomegaly (60%), and hepatomegaly (55%). Relapse occurred in three of six subjects started on single drug treatment, but in only one of 15 subjects who started on two or more drugs (p=0.053). No relapses occurred in children whose initial therapy included rifampin or those administered three-drug regimens. Brucella is an infrequent pathogen but should be considered in children with compatible epidemiologic and clinical characteristics. Blood cultures should be obtained, and initial therapy with two or more drugs may decrease the risk of relapse.

Protective Live Oral Brucellosis Vaccines Stimulate Th1 and Th17 Cell Responses

Zoonotic transmission of brucellosis often results from exposure to Brucella-infected livestock, feral animals, or wildlife or frequently via consumption of unpasteurized milk products or raw meat. Since natural infection of humans often occurs by the oral route, mucosal vaccination may offer a means to confer protection for both mucosal and systemic tissues. Significant efforts have focused on developing a live brucellosis vaccine, and deletion of the znuA gene involved in zinc transport has been found to attenuate Brucella abortus. A similar mutation has been adapted for Brucella melitensis and tested to determine whether oral administration of ΔznuA B. melitensis can confer protection against nasal B. melitensis challenge. A single oral vaccination with ΔznuA B. melitensis rapidly cleared from mice within 2 weeks and effectively protected mice upon nasal challenge with wild-type B. melitensis 16M. In 83% of the vaccinated mice, no detectable brucellae were found in their spleens, unlike with phosphate-buffered saline (PBS)-dosed mice, and vaccination also enhanced the clearance of brucellae from the lungs. Moreover, vaccinated gamma interferon-deficient (IFN-γ(-/-)) mice also showed protection in both spleens and lungs, albeit protection that was not as effective as in immunocompetent mice. Although IFN-γ, interleukin 17 (IL-17), and IL-22 were stimulated by these live vaccines, only RB51-mediated protection was codependent upon IL-17 in BALB/c mice. These data suggest that oral immunization with the live, attenuated ΔznuA B. melitensis vaccine provides an attractive strategy to protect against inhalational infection with virulent B. melitensis.

Brucellosis – forgotten but not gone

Brucellosis, a zoonotic infection, is transmitted to children primarily by consumption of unpasteurized milk products. It can present with symptom complexes that mimic common chronic arthritis/connective tissue disorders, notably Still's disease. We describe three children (Table ​(Table1)1) suffering from brucellosis, seen in the last year in our rheumatology services. Table 1 These cases reemphasize the need for pattern recognition in rheumatologic disease. All three were referred by primary care physicians with a working diagnosis of systemic onset JIA/autoimmune disorder. However the lack of a perfect fit for such diagnoses,(pattern of fever, absence of rash/serositis, normal white cell/platelet counts) led us to explore a history of travel/residence in endemic areas and ingestion of unpasteurized milk. A family history of similarly afflicted members in one case was also relevant. Serology is helpful but false positives may occur in hyper-gammaglobulinemic states. Blood cultures take weeks and the organism is a fastidious one. All three children responded well to a combination of streptomycin (2 weeks) and doxycycline (6 weeks).

Brucellosis as a cause of acute febrile illness in Egypt

To develop better estimates of brucellosis incidence, we conducted population-based surveillance for acute febrile illness (AFI) in Fayoum governorate (population 2347249), Egypt during two summer periods (2002 and 2003). All hospitals and a representative sample of community healthcare providers were included. AFI patients without obvious etiology were tested for brucellosis by culture and serology. Incidence estimates were calculated adjusting for sampling methodology and study period. Of 4490 AFI patients enrolled, 321 (7%) met the brucellosis case definition. The estimated annual incidence of brucellosis per 100000 population was 64 and 70 in 2002 and 2003, respectively. The median age of brucellosis patients was 26 years and 70% were male; 53% were initially diagnosed as typhoid fever. Close contact with animals and consumption of unpasteurized milk products were associated with brucellosis. The high incidence of brucellosis in Fayoum highlights its public health importance, and the need to implement prevention strategies in humans and animals.

An outbreak of Streptococcus equi subspecies zooepidemicusassociated with consumption of fresh goat cheese

BackgroundStreptococcus equi subspecies zooepidemicus is a rare infection in humans associated with contact with horses or consumption of unpasteurized milk products. On October 23, 2003, the National Public Health Institute was alerted that within one week three persons had been admitted to Tampere University Central Hospital (TaYS) because of S. equi subsp. zooepidemicus septicaemia. All had consumed fresh goat cheese produced in a small-scale dairy located on a farm. We conducted an investigation to determine the source and the extent of the outbreak.MethodsCases were identified from the National Infectious Disease Register. Cases were persons with S. equi subsp. zooepidemicus isolated from a normally sterile site who had illness onset 15.9-31.10.2003. All cases were telephone interviewed by using a standard questionnaire and clinical information was extracted from patient charts. Environmental and food specimens included throat swabs from two persons working in the dairy, milk from goats and raw milk tank, cheeses made of unpasteurized milk, vaginal samples of goats, and borehole well water. The isolates were characterized by ribotyping and pulsed-field gel electrophoresis (PFGE).ResultsSeven persons met the case definition; six had septicaemia and one had purulent arthritis. Five were women; the median age was 70 years (range 54–93). None of the cases were immunocompromized and none died. Six cases were identified in TaYS, and one in another university hospital in southern Finland. All had eaten goat cheese produced on the implicated farm. S. equi subsp. zooepidemicus was isolated from throat swabs, fresh goat cheese, milk tank, and vaginal samples of one goat. All human and environmental strains were indistinguishable by ribotyping and PFGE.ConclusionThe outbreak was caused by goat cheese produced from unpasteurized milk. Outbreaks caused by S. equi subsp. zooepidemicus may not be detected if streptococcal strains are only typed to the group level. S. equi subsp. zooepidemicus may be a re-emerging disease if unpasteurized milk is increasingly used for food production. Facilities using unpasteurized milk should be carefully monitored to prevent this type of outbreaks.

Human Tuberculosis Caused by Mycobacterium bovis: New York City, 2001–2004

In March 2004, a U.S.-born boy aged 15 months in New York City (NYC) died of peritoneal tuberculosis (TB) caused by Mycobacterium bovis infection. M. bovis, a bacterial species of the M. tuberculosis complex, is a pathogen that primarily infects cattle. However, humans also can become infected, most commonly through consumption of unpasteurized milk products from infected cows. In industrialized nations, human TB caused by M. bovis is rare because of milk pasteurization and culling of infected cattle herds. This report summarizes an ongoing, multiagency investigation that has identified 35 cases of human M. bovis infection in NYC. Preliminary findings indicate that fresh cheese (e.g., queso fresco) brought to NYC from Mexico was a likely source of infection. No evidence of human-to-human transmission has been found. Products from unpasteurized cow's milk have been associated with certain infectious diseases and carry the risk of transmitting M. bovis if imported from countries where the bacterium is common in cattle. All persons should avoid consuming products from unpasteurized cow's milk.