Robert G. Rivard

Real-time Monitoring of Cardiovascular Function in Rhesus Macaques Infected With Zaire ebolavirus

Nine rhesus macaques were implanted with multisensor telemetry devices and internal jugular vein catheters before being infected with Zaire ebolavirus. All animals developed viremia, fever, a hemorrhagic rash, and typical changes of Ebola hemorrhagic fever in clinical laboratory tests. Three macaques unexpectedly survived this usually lethal disease, making it possible to compare physiological parameters in lethally challenged animals and survivors. After the onset of fever, lethal illness was characterized by a decline in mean arterial blood pressure, an increase in pulse and respiratory rate, lactic acidosis, and renal failure. Survivors showed less pronounced change in these parameters. Four macaques were randomized to receive supplemental volumes of intravenous normal saline when they became hypotensive. Although those animals had less severe renal compromise, no apparent survival benefit was observed. This is the first report of continuous physiologic monitoring in filovirus-infected nonhuman primates and the first to attempt cardiovascular support with intravenous fluids.

Expansion of brucellosis detection in the country of Georgia by screening household members of cases and neighboring community members

BackgroundBrucellosis is considered as endemic zoonotic disease in the country of Georgia. However, the burden of the disease on a household level is not known. Therefore, this study sought to determine the benefits of active surveillance coupled to serological screening for the early detection of brucellosis among close contacts of brucellosis cases.MethodsWe used an active surveillance approach to estimate the rate of seropositivity among household family members and neighboring community members of brucellosis index cases. All participants were screened using the serum tube agglutination test (SAT). Blood cultures were performed, obtained isolates were identified by a bacteriological algorithm, and confirmed as Brucella spp. using real-time PCR. Further confirmation of Brucella species was done using the AMOS PCR assay.ResultsA total of 141 participants enrolled. Of these, 27 were brucellosis index cases, 86 were household family members, and 28 were neighboring community members. The serological evidence of brucellosis in the household member group was 7% and the rate at the household level was 21%. No screened community members were Brucella seropositive. Majority of brucellosis cases were caused by B. melitensis; only one index case was linked to B. abortus.ConclusionWe found evidence of brucellosis infection among household family members of brucellosis index cases. B. melitensis was the most common species obtained. Findings of this active surveillance study highlight the importance of screening household family members of brucellosis cases and of the use of culture methods to identify Brucella species in the country of Georgia.

Screening of Household Family Members of Brucellosis Cases and Neighboring Community Members in Azerbaijan

Brucellosis is an endemic zoonotic disease in Azerbaijan. The first human brucellosis case reported in 1922 was in Pardabil village of a region currently named Shabran. Household members of brucellosis index cases are a population at risk for brucellosis infection. The purpose of this study was to determine the rate of seropositivity of brucellosis among household and neighboring community members of brucellosis index cases in Azerbaijan. Twenty-one household members of 8 index brucellosis cases and 27 community neighbors were serologically tested for evidence of exposure by the serum agglutination test. Of these, the brucellosis seropositivity rate was 9.5% and 7.4%, respectively. Screening of household members of index cases and individuals who live in proximity to infected household members is a practical approach to increase the detection of brucellosis exposure.

A Comparison of the Adaptive Immune Response between Recovered Anthrax Patients and Individuals Receiving Three Different Anthrax Vaccines

Several different human vaccines are available to protect against anthrax. We compared the human adaptive immune responses generated by three different anthrax vaccines or by previous exposure to cutaneous anthrax. Adaptive immunity was measured by ELISPOT to count cells that produce interferon (IFN)-γ in response to restimulation ex vivo with the anthrax toxin components PA, LF and EF and by measuring circulating IgG specific to these antigens. Neutralising activity of antisera against anthrax toxin was also assayed. We found that the different exposures to anthrax antigens promoted varying immune responses. Cutaneous anthrax promoted strong IFN-γ responses to all three antigens and antibody responses to PA and LF. The American AVA and Russian LAAV vaccines induced antibody responses to PA only. The British AVP vaccine produced IFN-γ responses to EF and antibody responses to all three antigens. Anti-PA (in AVA and LAAV vaccinees) or anti-LF (in AVP vaccinees) antibody titres correlated with toxin neutralisation activities. Our study is the first to compare all three vaccines in humans and show the diversity of responses against anthrax antigens.

Etiologic Agents of Central Nervous System Infections among Febrile Hospitalized Patients in the Country of Georgia

Objectives There is a large spectrum of viral, bacterial, fungal, and prion pathogens that cause central nervous system (CNS) infections. As such, identification of the etiological agent requires multiple laboratory tests and accurate diagnosis requires clinical and epidemiological information. This hospital-based study aimed to determine the main causes of acute meningitis and encephalitis and enhance laboratory capacity for CNS infection diagnosis. Methods Children and adults patients clinically diagnosed with meningitis or encephalitis were enrolled at four reference health centers. Cerebrospinal fluid (CSF) was collected for bacterial culture, and in-house and multiplex RT-PCR testing was conducted for herpes simplex virus (HSV) types 1 and 2, mumps virus, enterovirus, varicella zoster virus (VZV), Streptococcus pneumoniae, HiB and Neisseria meningitidis. Results Out of 140 enrolled patients, the mean age was 23.9 years, and 58% were children. Bacterial or viral etiologies were determined in 51% of patients. Five Streptococcus pneumoniae cultures were isolated from CSF. Based on in-house PCR analysis, 25 patients were positive for S. pneumoniae, 6 for N. meningitidis, and 1 for H. influenzae. Viral multiplex PCR identified infections with enterovirus (n = 26), VZV (n = 4), and HSV-1 (n = 2). No patient was positive for mumps or HSV-2. Conclusions Study findings indicate that S. pneumoniae and enteroviruses are the main etiologies in this patient cohort. The utility of molecular diagnostics for pathogen identification combined with the knowledge provided by the investigation may improve health outcomes of CNS infection cases in Georgia.

Viral Hemorrhagic Fever Cases in the Country of Georgia: Acute Febrile Illness Surveillance Study Results

Minimal information is available on the incidence of Crimean-Congo hemorrhagic fever (CCHF) virus and hantavirus infections in Georgia. From 2008 to 2011, 537 patients with fever ≥ 38°C for ≥ 48 hours without a diagnosis were enrolled into a sentinel surveillance study to investigate the incidence of nine pathogens, including CCHF virus and hantavirus. Of 14 patients with a hemorrhagic fever syndrome, 3 patients tested positive for CCHF virus immunoglobulin M (IgM) antibodies. Two of the patients enrolled in the study had acute renal failure. These 2 of 537 enrolled patients were the only patients in the study positive for hantavirus IgM antibodies. These results suggest that CCHF virus and hantavirus are contributing causes of acute febrile syndromes of infectious origin in Georgia. These findings support introduction of critical diagnostic approaches and confirm the need for additional surveillance in Georgia.

Hospital-Based Surveillance for Infectious Etiologies Among Patients with Acute Febrile Illness in Georgia, 2008-2011.

Information on the infectious causes of undifferentiated acute febrile illness (AFI) in Georgia is essential for effective treatment and prevention. In May 2008, a hospital-based AFI surveillance was initiated at six hospitals in Georgia. Patients aged ≥ 4 years with fever ≥ 38°C for ≥ 48 hours were eligible for surveillance. Blood culture and serologic testing were conducted for Leptospira spp., Brucella spp., West Nile virus (WNV), Crimean-Congo hemorrhagic fever virus, Coxiella burnetii, tick-borne encephalitis virus (TBEV), hantavirus, Salmonella enterica serovar Typhi (S. Typhi), and Rickettsia typhi. Of 537 subjects enrolled, 70% were outpatients, 54% were males, and the mean age was 37 years. Patients reported having fatigue (89%), rigors (87%), sweating (83%), pain in joints (49%), and sleep disturbances (42%). Thirty-nine (7%) patients were seropositive for R. typhi, 37 (7%) for Brucella spp., 36 (7%) for TBEV, 12 (2%) for Leptospira spp., 10 (2%) for C. burnetii, and three (0.6%) for S. Typhi. None of the febrile patients tested positive for WNV antibodies. Of the patients, 73% were negative for all pathogens. Our results indicate that most of the targeted pathogens are present in Georgia, and highlight the importance of enhancing laboratory capacity for these infectious diseases.

Epidemiological and Clinical Features of Brucellosis in the Country of Georgia.

Background Brucellosis is an endemic disease in the country of Georgia. According to the National Center for Disease Control and Public Health of Georgia (NCDC), the average annual number of brucellosis cases was 161 during 2008–2012. However, the true number of cases is thought to be higher due to underreporting. The aim of this study was to provide current epidemiological and clinical information and evaluate diagnostic methods used for brucellosis in Georgia. Methodology Adult patients were eligible for participation if they met the suspected or probable case definition for brucellosis. After consent participants were interviewed using a standardized questionnaire to collect information on socio-demographic characteristics, epidemiology, history of present illness, and clinical manifestation. For the diagnosis of brucellosis, culture and serological tests were used. Results A total of 81 participants were enrolled, of which 70 (86%) were from rural areas. Seventy-four percent of participants reported consuming unpasteurized milk products and 62% consuming undercooked meat products before symptom onset. Forty-one participants were positive by the Wright test and 33 (41%) were positive by blood culture. There was perfect agreement between the Huddelston and Wright tests (k = 1.0). Compared with blood culture (the diagnostic gold standard), ELISA IgG and total ELISA (IgG + IgM), the Wright test had fair (k = 0.12), fair (k = 0.24), and moderate (k = 0.52) agreement, respectively. Conclusions Consumption of unpasteurized milk products and undercooked meat were among the most common risk factors in brucellosis cases. We found poor agreement between ELISA tests and culture results. This report also serves as an initial indication that the suspected case definition for brucellosis surveillance purposes needs revision. Further research is needed to characterize the epidemiology and evaluate the performance of the diagnostic methods for brucellosis in Georgia.

Patterns of brucellosis infection symptoms in azerbaijan: a latent class cluster analysis.

Brucellosis infection is a multisystem disease, with a broad spectrum of symptoms. We investigated the existence of clusters of infected patients according to their clinical presentation. Using national surveillance data from the Electronic-Integrated Disease Surveillance System, we applied a latent class cluster (LCC) analysis on symptoms to determine clusters of brucellosis cases. A total of 454 cases reported between July 2011 and July 2013 were analyzed. LCC identified a two-cluster model and the Vuong-Lo-Mendell-Rubin likelihood ratio supported the cluster model. Brucellosis cases in the second cluster (19%) reported higher percentages of poly-lymphadenopathy, hepatomegaly, arthritis, myositis, and neuritis and changes in liver function tests compared to cases of the first cluster. Patients in the second cluster had a severe brucellosis disease course and were associated with longer delay in seeking medical attention. Moreover, most of them were from Beylagan, a region focused on sheep and goat livestock production in south-central Azerbaijan. Patients in cluster 2 accounted for one-quarter of brucellosis cases and had a more severe clinical presentation. Delay in seeking medical care may explain severe illness. Future work needs to determine the factors that influence brucellosis case seeking and identify brucellosis species, particularly among cases from Beylagan.

A Review of the English and Russian Language Literature on the Osteoarticular Manifestations of Brucellosis Infection

Brucellosis continues to adversely affect human health throughout the world. Acute and chronic osteoarticular manifestations of brucellosis include sacroiliitis, spondylitis, peripheral arthritis, osteomyelitis, and bursitis. Substantial clinical experience with the presentation, clinical course, and treatment of brucellosis exists in countries of the former Soviet Union, including the Republic of Georgia. The present article reviews the unique Georgian and Russian medical literature in addition to the English-language medical literature on the topic of osteoarticular complications of brucellosis. Special emphasis is placed on current diagnostic approaches for osteoarticular brucellosis, including imaging techniques and laboratory tests (bacteriology, serology, PCR).