Significant Differences In Antibody Prevalence Research Articles

ANTIBODY PREVALENCE TO AFRICAN SWINE FEVER VIRUS, MYCOBACTERIUM BOVIS, FOOT-AND-MOUTH DISEASE VIRUS, RIFT VALLEY FEVER VIRUS, INFLUENZA A VIRUS, AND BRUCELLA AND LEPTOSPIRA SPP. IN FREE-RANGING WARTHOG (PHACOCHOERUS AFRICANUS) POPULATIONS IN SOUTH AFRICA.

The warthog (Phacochoerus africanus) can be used as a model for investigating disease transmission at the human, wildlife, and livestock interface. An omnivore and scavenger, a warthog moves freely between natural ecotypes, farmland, and human communities and is susceptible to diseases of zoonotic, agricultural, and conservation concern. A retrospective study using 100 individual serum samples collected from May 1999 to August 2016 was performed to determine antibody prevalence to seven pathogens in warthogs from five locations in northeastern South Africa. Higher prevalence of antibodies to African swine fever virus and Mycobacterium bovis were detected in warthogs from the Greater Kruger National Park ecosystem in comparison to lower prevalence of antibodies to M. bovis and no antibodies to African swine fever virus in warthogs from uMhkuze Game Reserve. Low prevalence of antibodies to foot-and-mouth disease virus, Rift Valley fever virus, and influenza A virus was detected in all locations, and no antibodies against Brucella and Leptospira spp. were detected. No statistically significant difference in antibody prevalence was found between sexes for any disease. At the univariate analysis, M. bovis seropositivity was significantly different among age categories, with 49% (35/71) of adults found positive versus 29% (4/14) of juveniles and 9% (1/11) of sub-adults (Fisher's exact test, P=0.020), and between the sampling locations (Fisher's exact test, P=0.001). The multivariate model results indicated that juvenile warthogs had lower odds of testing positive to M. bovis antibodies than adults (juveniles' odds ratio [OR]=0.17, 95% confidence interval [CI]: 0.02-1.0), although this result was not statistically significant at the 5% level (P=0.052). For warthogs sampled at Satara Buffalo Camp, the odds (OR=0.22, 95% CI: 0.035-0.96) of being M. bovis antibody positive were significantly lower (P=0.043) than for warthogs sampled at Skukuza. Of particular interest in this study was the detection of warthogs seropositive for influenza A virus.

Prevalence of serum anti-neuronal autoantibodies in patients admitted to acute psychiatric care.

Autoimmune encephalitis associated with anti-neuronal antibodies may be challenging to distinguish from primary psychiatric disorders. The significance of anti-neuronal antibodies in psychiatric patients without clear evidence of autoimmune encephalitis is unknown. We investigated the serum prevalence of six anti-neuronal autoantibodies in a cohort of unselected patients admitted to acute psychiatric care. Serum was drawn from 925 patients admitted to acute psychiatric in-patient care. Psychiatric diagnoses were set according to International Classification of Diseases (ICD)-10 criteria. Antibody analysis was performed with an indirect immunofluorescence test for N-methyl d-aspartate receptor (NMDAR) antibodies and five other anti-neuronal autoantibodies of the immunoglobulin (Ig) classes IgA, IgG and IgM isotype. Anti-neuronal autoantibodies were found in 11.6% of patients: NMDAR antibodies in 7.6%, contactin-associated protein-like 2 (CASPR2) antibodies in 2.5%, glutamic acid decarboxylase-65 (GAD65) antibodies in 1.9%, and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antibodies in 0.1%. Leucine-rich glioma-inactivated protein-1 (LGI1) and γ-aminobutyric acid B (GABAB) receptor antibodies were not detected. NMDAR antibodies of class IgG were present in five patients only (0.5%). NMDAR antibodies of all Ig classes were equally prevalent in patients with and without psychosis. There were no significant differences in antibody prevalence in the different diagnostic categories, except for a higher odds ratio of being NMDAR antibody positive for patients without a specific psychiatric diagnosis. NMDAR IgG autoantibodies, which are known to be strongly associated with anti-NMDAR encephalitis, were rarely found. CASPR2 and GAD65 antibodies were more frequently encountered in the present study than previously reported. Further research on the clinical significance of anti-neuronal autoantibodies in patients with acute psychiatric symptoms is needed.

PREVALENCE OF ANTIBODY TO ALEUTIAN MINK DISEASE VIRUS IN EUROPEAN MINK (MUSTELA LUTREOLA) AND AMERICAN MINK (NEOVISON VISON) IN SPAIN.

The European mink (Mustela lutreola) has undergone a dramatic decline and is one of the most endangered mammals in the world. The invasive American mink (Neovison vison) is considered the main factor for this decline. However, the American mink's introduction and the subsequent ecological concurrence of the two species cannot solely explain the decline or disappearance of the European mink. Aleutian mink disease virus (AMDV) is the main health problem in fur farming worldwide, causing varied clinical syndromes that depend on the viral strain and host factors. Infection with AMDV has been speculated to contribute to the decline of the European mink, but a detailed study has not been performed. To assess the potential effects of AMDV infection on the conservation of the European mink, we surveyed AMDV antibody in samples from 492 native European mink and 1,735 feral American mink collected over 16 yr. The antibody prevalence in European mink was 32%. There were no statistically significant differences in antibody prevalence between sexes, among years, or among weight classes. For recaptured European mink, incidence of seroconversion (negative to positive) was 0.46 cases per animal-year at risk. For positive animals, the incidence of conversion from positive to negative was 0.18 cases per animal-year at risk. In 1,735 feral American minks, the overall prevalence was 32.4% and varied among the six wild populations studied. Infection with AMDV appears to be endemic, distributed across the entire ranges of both species, and no effects on the population dynamics of either species were observed.

Henipaviruses and Fruit Bats, Papua New Guinea

Henipaviruses and Fruit Bats, Papua New Guinea

INBREEDING DEPRESSION INCREASES SUSCEPTIBILITY TO BOVINE TUBERCULOSIS IN LIONS: AN EXPERIMENTAL TEST USING AN INBRED–OUTBRED CONTRAST THROUGH TRANSLOCATION

Disease can dramatically influence the dynamics of endangered wildlife populations, especially when they are small and isolated, with increased risk of inbreeding. In Hluhluwe-iMfolozi Park (HiP), a small, enclosed reserve in South Africa, a large lion (Panthera leo) population arose from a small founder group in the 1960s and started showing conspicuous signs of inbreeding. To restore the health status of the HiP lion population, outbred lions were translocated into the existing population. In this study, we determined the susceptibility to bovine tuberculosis (bTB), and the prevalence of antibody to feline viruses of native lions, and compared the findings with those from translocated outbred lions and their offspring. Antibodies to feline herpesvirus, feline calicivirus, feline parvovirus, and feline coronavirus were present in the lion population, but there was no significant difference in antibody prevalence between native and translocated lions and their offspring, and these feline viruses did not appear to have an effect on the clinical health of HiP lions. However, feline immunodeficiency virus (FIV), which was previously absent from HiP, appears to have been introduced into the lion population through translocation. Within 7 yr, the prevalence of antibody to FIV increased up to 42%. Bovine tuberculosis posed a major threat to the inbred native lion population, but not to translocated lions and their offspring. More than 30% of the native lion population died from bTB or malnutrition compared with <2% of the translocated lions and their offspring. We have demonstrated that management of population genetics through supplementation can successfully combat a disease that threatens population persistence. However, great care must be taken not to introduce new diseases into populations through translocation.

EPIZOOTIOLOGY OF BRUCELLA INFECTION IN AUSTRALIAN FUR SEALS

Novel members of the bacterial genus Brucella have recently emerged as pathogens of various marine mammal species and as potential zoonotic agents. We investigated the epizootiology of Brucella infection in Australian fur seals (Arctocephalus pusillus doriferus) by establishing demographic and temporal variations in antibody prevalence, attempting isolation of the causative agent, and determining whether this potential pathogen is involved in frequent abortions observed in this pinniped species. Two competitive enzyme-linked immunosorbent assays (cELISAs), an indirect ELISA, and a fluorescence polarization assay (FPA) were used to test sera for Brucella antibodies. The FPA and cELISA proved suitable for use in this species. Significant differences in antibody prevalence were found between age classes of seals sampled between 2007 and 2009 at one colony. Pups sampled at this site (n=134) were negative for Brucella antibodies by all serologic tests but 17 of 45 (38%) of juveniles were antibody-positive. Antibody prevalence in adult females was significantly higher than in juveniles (P=0.044). Antibody prevalence for adult females between 2003 and 2009 varied significantly over time (P=0.011), and for individuals sampled between 2003 and 2005, the likelihood of pregnancy was greater in individuals positive for Brucella antibodies (P=0.034). Inflammatory lesions suggestive of infectious agents were found in 14 of 39 aborted Australian fur seal pups, but pathologic changes were not uniformly consistent for Brucella infection. Culture and PCR investigations on fetal tissues were negative for Brucella. Culture and PCR on selected fresh or frozen tissues from 36 juvenile and adult animals were also negative. We suspect that the prevalence of active infection with Brucella in Australian fur seals is low relative to antibody prevalence.

Prevalence of antibodies against Toxoplasma gondii in roe deer from Spain

Roe deer ( Capreolus capreolus) is an important game animal in Spain. Sera from 278 roe deer from eight areas in mainland Spain were assayed for antibodies to Toxoplasma gondii by modified agglutination test (MAT). Titers of 1:25 or higher were found in 109 (39.2%) of 278 deer. No significant differences in antibody prevalence were found between sex or age categories. In contrast, significant differences in seroprevalence between locations were evident. Roe deer from the Northern coastal habitats (high humidity and roe deer density) had the highest prevalence, compared with low prevalence in Central Spain (arid areas and low roe deer density). There was a positive correlation between antibody prevalence and mean annual rainfall ( r s = 0.85, n = 8, P < 0.01). These findings have environmental and/or public health implications because venison can be an important meat source of T. gondii infections for humans and feral cats.

Prevalence of antibodies against canine distemper virus and canine parvovirus among foxes and wolves from Spain

Viral diseases can influence the population dynamics of wild carnivores and can have effects on carnivore conservation. Hence, a serologic survey was conducted in an opportunistic sample of 137 foxes ( Vulpes vulpes) and 37 wolves ( Canis lupus) in Spain for 1997–2007 to detect antibodies against canine distemper virus (CDV) and against canine parvovirus (CPV) by indirect ELISA. Antibodies against CDV were detected in 18.7% of the analyzed animals and antibodies against CPV in 17.2%. There was no difference in antibody prevalence to CDV between both species, even in the same region ( P > 0.05), but there was a significant difference in antibody prevalence to CPV between foxes (5.1%) and wolves (62.2%) ( P < 0.05). In fox populations there was a significant difference in antibody prevalence to CDV between geographic areas (Aragón 26.4%, La Mancha 7.8%, P < 0.05). In wolf populations there was significantly higher antibody prevalence against CPV ( P < 0.05) in Castilla y León (100%) than in the Cantabric region (53.3%). There was no significant sex or age-related difference in the antibody prevalence against CDV or CPV in foxes. These results indicate that contact with CDV is widespread among wild canid populations in Spain and that CPV is endemic in the Iberian wolf population. The implications of these results are briefly discussed.

Serologic evidence of infection with granulocytic ehrlichiae in black bears in Pennsylvania.

Serum samples from 381 black bears (Ursus americanus) killed in Pennsylvania (USA) on 24 November 1997 were analyzed for antibodies reactive to the agent of human granulocytic ehrlichiosis (HGE; Ehrlichia sp.) by indirect immunofluorescence assay. Antibody reactivity to HGE antigen was detected in 21% (81/381) of the samples collected. Reactive samples were reported from 56% (14/25) of the counties where bear samples were collected. Endpoint antibody titer ranged from 1:8 to 1:16, 192, with a geometric mean titer of 1:582. There was no significant difference in antibody prevalence between male and female bears (P < 0.01). However, adult bears were significantly more likely to have reactive antibodies than juvenile bears (P < 0.01). Attempts to amplify and detect granulocytic ehrlichial DNA from corresponding bear blood clots (n = 181) through nested polymerase chain reaction assays were unsuccessful. Further studies are needed for identification of the pathogen-responsible for induction of HGE-reactive. This is the first description of antibodies reactive to the HGE agent in black bears and suggests these mammals are infected with the agent of HGE or an antigenically related ehrlichial species.

Viral diseases of northern ungulates

This paper describes viral diseases reported in northern ungulates and those that are a potential threat to these species. The following diseases are discussed: bovine viral diarrhoea/mucosal disease (BVD/MD), alphaherpesvirus infections, malignant catarrhal fever (MCF), poxvirus infections, parainfluenza type 3 virus infection, Alvsborg disease, foot-and-mouth disease, epizootic haemorrhage disease of deer and bluetongue disease, rabies, respiratory syncytial virus infection, adenovirus infection, hog-cholera, Aujeszky's disease and equine herpesvirus infections. There are no significant differences in antibody prevalence to BVDV among deer in habitats with high, intermediate and low density of cattle. In addition, sequence analysis from the BVDV isolated from roe deer (Capreolus capreolus) showed that this strain was unique within BVDV group I. Distinct BVDV strains might circulate in free-ranging roe deer populations in Germany and virus transmission may be independent of domestic livestock. Similar results have been obtained in a serological survey of alpha-herpesviruses in deer in Germany. Malignant catarrhal fever was studied in fallow deer (Cervus dama) in Germany: the seroprevalence and positive PCR results detected in sheep originating from the same area as the antibody-positive deer might indicate that sheep are the main reservoir animals. Contagious ecthyma (CE) is a common disease in domestic sheep and goats caused by the orf virus. CE has been diagnosed in Rocky Mountain bighorn sheep (Ovis canadensis), mountain goats (Oreamnos americanus), Dall sheep (Ovis dalli), chamois (Rupkapra rupi-capra), muskox {Ovibos moschatus) and reindeer (Rangifer tarandus). Most parainfluenza type 3 virus infections are mild or clinically undetectable. Serological surveys in wildlife have been successfully conducted in many species. In 1985, a new disease was identified in Swedish moose (Alces alces), designated as Alvsborg disease. This wasting syndrome probably has a multi-factorial etiology. Foot-and-mouth disease virus (FMDV) can infect deer and many other wild artiodactyls. Moose, roe deer and the saiga antelope (Saiga tatarica) are the main hosts of FMDV in the Russian Federation. In addition, serological evidence of a FMD infection without clinical disease was detected in red deer in France. Epizootic haemorrhage disease of deer (EHD) and bluetongue (BT) are acute non-contagious viral diseases of wild ruminants characterised by extensive haemorrhage. Culicoides insects are the main vectors. EHD and BT only play a minor role in Europe but both diseases are widespread in North America.

Decay of passively acquired maternal antibodies against measles, mumps, and rubella viruses.

The decay of maternally derived antibodies to measles, mumps, and rubella viruses in Swiss infants was studied in order to determine the optimal time for vaccination. A total of 500 serum or plasma samples from infants up to 2 years of age were tested by enzyme-linked immunosorbent assay and fluorescent-antibody testing. The decline of antibody prevalence was slowest against the measles virus. By 9 to 12 months of age, only 5 of 58 (8.6%; 95% CI, 2.9 to 19.0) infants were antibody positive for the measles virus, and only 2 had levels above 200 mIU/ml. Mumps and rubella virus antibody seropositivity was lowest at 9 to 12 months of age with 3 of 58 (5. 2%; 95% CI, 1.1 to 14.4) infants and at 12 to 15 months with 1 of 48 (2.1%; 95% CI, 0.1 to 11.1) infants, respectively. Concentrations of passively acquired antibodies decreased rapidly within the first 6 months of life. We observed no significant differences in antibody prevalence or concentration according to gender in any age group. In conclusion, MMR vaccination at 12 instead of 15 months of age could reduce the pool of susceptible subjects in infancy and support the efforts to eliminate these infections, particularly in combination with a second vaccine dose before school entry.

Bovine virus diarrhea and mucosal disease in free-ranging and captive deer (Cervidae) in Germany.

From 1990 until 1992, 355 blood samples of roe deer (Capreolus capreolus) (n = 123), red deer (Cervus elaphus) (n = 60), fallow deer (Dama dama) (n = 87) and other cervid species (n = 85) from three different habitats (n = 180) and 11 wildlife parks or zoos (n = 175) in Germany were tested for prevalence of pestivirus antibodies. Seventeen samples were seropositive for bovine viral diarrhea virus (BVDV); only one animal had antibodies for Border disease virus. Microneutralization test titers ranged from 1:5 to 1:125. We found no significant difference in antibody prevalence among deer in habitats with high, intermediate and low density of cattle. There were significantly more seropositive individuals in roe deer compared to fallow deer. Significantly more seropositive individuals were found among juvenile animals than among adults. Antibody prevalence in free-ranging cervids was significantly higher compared with that of deer in enclosures. Antibody prevalence in summer was significantly higher than in winter.

Prevalence of Antibodies to Norwalk Virus among Amerindlans In Isolated Amazonian Communities

The seroepidemiology of Norwalk virus infections was examined among Amerindians belonging to eight relatively isolated communities in the Amazon region by means of a new enzyme immunoassay using recombinant Norwalk virus antigen. The seroprevalence of antibodies to Norwalk virus ranged from 39% in the Maiogong to 100% in the Kubenkrankrein. The distribution of antibody levels varied greatly among groups; five of the eight communities had an antibody prevalence greater than 90% with many high values (> 100 units), while three had both a low seroprevalence and a preponderance of low values (< 100 units). While few children less than 5 years of age were sampled, no significant differences in antibody prevalence were noted among age groups, and the prevalence of antibody among children 5-10 years of age approached that of the older age groups. The low prevalence of titers of antibodies to Norwalk virus in several tribes living in these isolated Indian communities suggests that Norwalk virus may have been only recently introduced.

Prevalence of Toxoplasma gondii Infections in Pennsylvania Black Bears, Ursus americanus

Serum samples from 665 hunter-killed black bears killed in 1989 to 1992 throughout Pennsylvania (USA) were tested for Toxoplasma gondii antibodies by the agglutination test in dilutions of 1:25, 1:50, and 1:500. Toxoplasma gondii antibodies were found in 535 of 665 (80%) bears. Considering the highest dilutions at which antibodies were detected, prevalences were 10% at 1:25, 37% at 1:50 and 33% at 1:500. No significant difference in antibody prevalence was found between males (79%) and females (80%), but a significant difference was found between juvenile (65%) and adult (83%) bears.

Survey for antibodies against flaviviruses in slaughter camels ( Camelus dromedarius) imported to Nigeria

A slaughter house survey for antibodies against flaviviruses in 269 camels was carried out in Borno State, Nigeria. Sera were tested by haemagglutination-inhibition (HI) tests against six flavivirus antigens: Wesselsbron, Yellow Fever, Potiskum, Uganda S, Dengue type 1 and Banzi viruses. Ninety-eight percent of sera tested were positive for flavivirus HI antibodies. Antibody prevalence against flaviviruses was noted as follows: Wesselsbron (60.2%), Yellow Fever (54.0%), Potiskum (66.2%), Dengue type 1 (4.5%), Banzi (5.2%) and Uganda S (0%). There was a significant difference in antibody prevalence between virus antigens. The degree of cross-reactivity among the virus antigens was also statistically significant. Potiskum, Yellow Fever and Wesselsbron viruses were closely related when compared with other virus antigens (Dengue type 1 and Banzi), which were markedly different from them. We suggest that cross-protection between flaviviruses has an influence upon the epidemiology of this group of viruses in Africa, and that the high prevalence of flaviviruses antibodies in slaughter camels imported to Nigeria may have serious public health implications.

Spectrum of natural antibodies against five HTLV-III antigens in infected individuals: correlation of antibody prevalence with clinical status

The genome of the HTLV-III/LAV retrovirus, the etiologic agent of the acquired immunodeficiency syndrome (AIDS), encodes the viral structural proteins (envelope and core proteins), the reverse transcriptase, a transactivation protein (tat-III), as well as two other proteins (3'orf, sor) of unknown function. We studied the prevalence of natural antibodies against envelope, gag, 3'orf, sor, and tat-III in the sera of HTLV-III infected individuals in an attempt to correlate clinical status with seropositivity to specific HTLV-III antigens. We selected 101 sera; 16 were obtained from normal donors with no known risk factors, and 85 were from patients with full-fledged AIDS (28 cases), AIDS-related complex (ARC, 22 cases), and healthy people at risk (homosexuals, intravenous [IV] drug users, relatives of AIDS patients; 35 cases). Seropositivity for antibodies against the envelope (gp41) and gag antigens (p15, p24) was determined by Western blot using disrupted HTLV-III virions. Of the 101 sera, all 16 from nonrisk donors and 3/35 from healthy at-risk donors were negative for antibodies against either the gp41 or p15 and p24. The remaining 82 sera were seropositive for either the gp41 and/or the p15 and p24. All sera were then tested against the three known HTLV-III antigens (3'orf, sor, and tat-III) that have been synthesized in bacteria. Our data indicate that all the HTLV-III antigens tested are immunogenic in vivo. No significant difference in antibody prevalence to gp41 (close to 100%) and to the 3'orf, sor, and tat-III proteins (approximately 50%) was observed with regard to stage of the disease. In contrast, the prevalence of antibodies against the core antigens decreased from approximately 100% in infected people with no clinical signs of disease to 50% in ARC and AIDS patients. The percentage of patients seropositive for all five antigens tested was increased in the AIDS group. These results indicate that the greatest antibody prevalence was obtained using viral envelope antigen and further suggest that screening with the newly identified 3'orf, sor, and tat-III proteins as antigens would confer no further diagnostic advantage. The pattern of natural antibodies observed during disease progression did not suggest any pathogenetic mechanism.

Spectrum of Natural Antibodies Against Five HTLV-III Antigens in Infected Individuals: Correlation of Antibody Prevalence With Clinical Status

Abstract The genome of the HTLV-III/LAV retrovirus, the etiologic agent of the acquired immunodeficiency syndrome (AIDS), encodes the viral structural proteins (envelope and core proteins), the reverse transcriptase, a transactivation protein (tat-III), as well as two other proteins (3′orf, sor) of unknown function. We studied the prevalence of natural antibodies against envelope, gag, 3′orf, sor, and tat-III in the sera of HTLV-III infected individuals in an attempt to correlate clinical status with seropositivity to specific HTLV-III antigens. We selected 101 sera; 16 were obtained from normal donors with no known risk factors, and 85 were from patients with full-fledged AIDS (28 cases), AIDS-related complex (ARC, 22 cases), and healthy people at risk (homosexuals, intravenous [IV] drug users, relatives of AIDS patients; 35 cases). Seropositivity for antibodies against the envelope (gp41) and gag antigens (p15, p24) was determined by Western blot using disrupted HTLV-III virions. Of the 101 sera, all 16 from nonrisk donors and 3/35 from healthy at-risk donors were negative for antibodies against either the gp41 or p15 and p24. The remaining 82 sera were seropositive for either the gp41 and/or the p15 and p24. All sera were then tested against the three known HTLV-III antigens (3′orf, sor, and tat-III) that have been synthesized in bacteria. Our data indicate that all the HTLV-III antigens tested are immunogenic in vivo. No significant difference in antibody prevalence to gp41 (close to 100%) and to the 3′orf, sor, and tat-III proteins (approximately 50%) was observed with regard to stage of the disease. In contrast, the prevalence of antibodies against the core antigens decreased from approximately 100% in infected people with no clinical signs of disease to 50% in ARC and AIDS patients. The percentage of patients seropositive for all five antigens tested was increased in the AIDS group. These results indicate that the greatest antibody prevalence was obtained using viral envelope antigen and further suggest that screening with the newly identified 3′orf, sor, and tat-III proteins as antigens would confer no further diagnostic advantage. The pattern of natural antibodies observed during disease progression did not suggest any pathogenetic mechanism.

Seroconversion rates to Jamestown Canyon virus among six populations of white-tailed deer (Odocoileus virginianus) in Indiana.

The annual seroconversion of fawns, yearlings, and adult white-tailed deer (Odocoileus virginianus) to Jamestown Canyon virus (California group) was followed at six Indiana sites from 1981 through 1984. In all, sera from 1,642 deer (515 fawns, 618 yearlings, and 509 adults) were tested for neutralizing antibody to three California serogroup viruses: Jamestown Canyon, La Crosse, and trivittatus. Virtually all deer with specific neutralizing antibody showed evidence of a prior infection with Jamestown Canyon virus; only three deer showed evidence of a prior infection with only La Crosse virus and none showed evidence of an infection with only trivittatus virus. While there were no significant differences in antibody prevalence to Jamestown Canyon virus between yearling and adult deer at any site, fawns had significantly lower antibody prevalences than either of the two older age groups. Significant differences in antibody prevalence were found between northern versus southern populations of white-tailed deer in Indiana, however, no significant differences were found among the four northern populations or between the two southern populations. The mean antibody prevalences in the two southern fawn, yearling, and adult populations were 15%, 38%, and 41% respectively, while the prevalences in the four northern fawn, yearling, and adult populations were 5%, 67%, and 67% respectively. These different prevalences (northern vs. southern) correlate with the higher Jamestown Canyon virus antibody prevalence in human residents of northern Indiana (2-15%) compared to residents of southern Indiana (less than 2%) found in other studies. The significantly lower prevalence of antibody to Jamestown Canyon virus in fawns is attributed to maternal antibody protecting them from a primary infection their first summer. Yearling deer showed high rates of seroconversion following their second summer of life. These results suggest that infection of white-tailed deer in Indiana with Jamestown Canyon virus is a common phenomenon.

Etiologic and serologic investigations of the 1980 epidemic of dengue fever on Hainan Island, China.

Virologic and seroepidemiologic studies were carried out during an epidemic of dengue fever on Hainan Island in 1980. Dengue 3 virus was isolated from 46 of 77 acute phase sera and from 1 of 10 pools of adult Aedes aegypti. Dengue 1 virus virus was isolated from a single acute phase serum. Seroepidemiologic investigations showed that 74% of healthy individuals in the epidemic area had antibody to dengue virus compared to 54% in an area where epidemic dengue had occurred in 1978, and less than or equal to 8% in nonepidemic areas. There were no significant differences in antibody prevalence for different sex and age groups.

Seroepidemiology of viral and toxoplasmal infections during pregnancy among Arab women of child-bearing age in Kuwait.

Five hundred and seventy three of 606 (94.6%), 583 of 604 (96.5%) and 575 of 595 (96.6%) women were found to have antibody to rubella virus, cytomegalovirus and herpes simplex virus, respectively. The Geometric Mean Titre (GMT) of haemagglutination-inhibition antibody to rubella virus was 60.97, while the GMT of complement-fixation antibody to cytomegalovirus and herpes simplex virus were 28.49 and 25.01, respectively. Furthermore, 301 of 517 (58.2%) women were also found to possess antibody to toxoplasma (GMT = 10.12) as detected by the passive-haemagglutination test. No significant differences in antibody prevalence or GMT could be found among the various nationalities studied except among Bedouins who showed a significantly higher rate and GMT of antibody to rubella virus and for the Mediterranean Arabs who showed significantly higher rate of immunity to and GMT of toxoplasma antibody when compared to other nationalities. Finally, no significant differences in antibody prevalence or GMT could be found among the various age groups.