Human toxocariasis: a seroepidemiological survey in schoolchildren of Sorocaba, Brazil

A seroepidemiological survey for toxocariasis, among 180 schoolchildren of the public schools of Sorocaba City, state of S?o Paulo, Brazil, was carried out from August 2000 to July 2001. ELISA test was performed using excretory and secretory antigens for the detection of IgG anti-Toxocara antibodies. Information regarding the children was obtained from the parents or legal guardians. The results showed that the mean age was 5.4 +/- 1.4 years, the infection coefficient (IC) was 38.3 and the infection risk was higher among the children living in the city outskirts (IC = 47.4) where the socioeconomic conditions were worse than in the central region of the city (IC = 11.1). There was an association between higher frequency of seroreactivity in the ELISA test and the condition of living in a house with a yard and/or unpaved street. The same was observed in relation to a history of enteroparasitism. There was also an association between a seronegative ELISA test and previous treatment of pet dogs and/or cats with vermifuge. Based on these results, the authors propose that public health programs should include anthelmintic for dogs and cats during the antirabies vaccination campaigns, in order to diminish environmental contamination with Toxocara spp. eggs and consequently human infection.     

Serologic evidence of human metapneumovirus circulation in Uruguay

First identified in 2001, the human metapneumovirus (hMPV), is a respiratory tract pathogen that affects young children, elderly, and immunocompromised patients. The present work represents the first serologic study carried out in Uruguay. It was performed with the purpose of obtaining serological evidence of hMPV circulation in Uruguay and to contribute to the few serologic reports described until now. Sixty nine serum samples collected between 1998 and 2001 by vein puncture from patients without respiratory symptoms or underlying pathology aged 6 days to 60 years were examined using an indirect immunofluorescence assay (IFA). The global seropositivity rate of the samples was 80% (55/69). Rates of 60% (15/25) and 91% (40/44) were observed for the pediatric and adult cohorts, respectively. Results obtained from a longitudinal analysis of 6 children aged 6 days to 18 months are discussed. These results are a clear evidence of hMPV circulation in Uruguay, at least since 1998, and reinforce the previous data on worldwide circulation of this virus.     

Erythrocytary zinc and the infant growth profile in northeast Brazil

This study evaluated nutritional status linked to zinc levels in 239 randomly selected children at crèches in Teresina, Brazil, aged 3 to 6. Blood samples were collected after fasting of 10 h. Erythrocytary zinc levels were determined through flame atomic absorption spectrophotometry. Zinc deficiency was determined as below 40 microg Zn/g Hb. Infant linear growth was evaluated measuring weight and height, and nutritional status by height/age, weight/height, and weight/age indices, expressed as Z scores, in line with the National Center for Health Statistics. The mean zinc concentration was 35.50 +/- 10.95 microg Zn/g Hb. Zinc distribution in the 10, 50, 75, and 90 percentiles was 24.73 microg Zn/g Hb, 35.45 microg Zn/g Hb, 40.73 microg Zn/g Hb and 52.77 microg Zn/g Hb, respectively. Based on this distribution, normal values were found only from the 75th percentile and above. Since the cutoff point adopted was 40 microg Zn/g Hb, the prevalence of zinc deficiency was 74.3%. As for growth profile, 8.4% were chronically malnourished, although the statistical association between linear impairment and nutritional status regarding zinc was insignificant. The study revealed that an important segment of the infant population was mineral deficient; however, the degree of deficiency did not influence growth profiles.     

Serologic evidence of hantavirus infection in sigmodontine rodents in Mexico

Antibodies to hantaviruses in two species of sigmodontine rodents (Peromyscus maniculatus and Reithrodontomys sumichrasti) collected in central Mexico are reported. Peromyscus maniculatus, a common species throughout much of Mexico, is the reservoir of Sin Nombre virus (SNV), the etiologic agent of the great majority of cases of hantavirus pulmonary syndrome (HPS) in North America. Although the identity of the virus detected in P. maniculatus in Mexico could not be determined by these serologic results, our findings suggest that SNV may occur throughout the range of P. maniculatus in North America. If true, the failure to identify HPS in Mexico is not due to the absence of pathogenic hantaviruses in Mexico.     

Serologic evidence of arboviral infections in white-tailed deer from central Wisconsin

A survey conducted during 1979-1980 on white-tailed deer (Odocoileus virginianus) in central Wisconsin revealed serological evidence of infection by selected arboviruses. Among sera from 41 deer, antibody was detected for Jamestown Canyon virus (56%) and Bunyamwera group virus (80%), demonstrating their continuing endemic activity. Antibody for La Crosse virus, not found previously in sera from deer in central Wisconsin, also was detected (5%) in this study.     

Serologic and molecular evidence of Ehrlichia spp. in coyotes in California

In order to determine the role of coyotes in the epidemiology of granulocytic and monocytic ehrlichial agents in California (USA), we tested 149 serum samples for antibodies against Ehrlichia equi, E. risticii, and E. canis, using an indirect immunofluorescent antibody test. Polymerase chain reaction (PCR) assay was used to survey for the presence of members of the E. phagocytophila genogroup, E. risticii and E. canis in blood samples of 95 coyotes. Sixty-eight (46%) samples were seropositive for E. equi, two (1%) for E. risticii and none of the samples had antibodies reactive to E. canis. Two and one coyote were positive for E. risticii and members of the E. phagocytophila genogroup by PCR assay, respectively. In contrast, the 95 samples were negative for E. canis by PCR. Ninety-five percent of the 68 E. equi seropositive coyotes and the one coyote PCR positive for members of the E. phagocytophila genogroup originated from a coastal area. However, the two E. risticii seropositive coyotes and the two coyotes PCR positive for E. risticii were from northern California. Sequence analysis of the three amplified PCR products revealed the agent to be similar in two coyotes to the sequences of E. risticii from horses originating from northern California and identical in one coyote to the agent of human granulocytic ehrlichiosis and E. equi from California. Thus, coyotes are exposed to granulocytic ehrlichiae and E. risticii and may play a role in the epidemiology of these ehrlichial agents in California.     

Vibrio parahaemolyticus serovar O3:K6 gastroenteritis in northeast Brazil

Aims:  To examine the virulence factors and the genetic relationship isolates of the serogroup O3 of Vibrio parahaemolyticus in outbreaks of diarrhoea in the northeast region of Brazil.
Methods and Results:  Eighteen samples of the O3:K6 and O3:KUT serotypes of V. parahaemolyticus were analysed by multiplex polymerase chain reaction (m-PCR) for detection of the tl , tdh and trh genes, by random-amplified polymorphic DNA (RAPD) using two primers, and by amplification of the rDNA 16S–23S region. The gene tl was amplified in all the samples, tdh in 16 while trh in none; amplification of rDNA 16S–23S generated only one profile; each RAPD primer produced two amplification patterns allowing grouping two tdh ^– Kanagawa-negative isolates.
Conclusions:  V. parahaemolyticus with characteristics of the pandemic clone appears to be widely disseminated in the studied region. Because of the genetic uniformity of the isolates, elucidation of outbreaks or tracking the source of contamination by the present molecular techniques seems useless.
Significance and Impact of the Study:  Detection of V. parahaemolyticus with virulence potential of pandemic clone from two outbreaks and from several isolated gastroenteritis cases points out the need for inclusion of this micro-organism in the Brazilian routine monitoring of the diarrhoeas for elucidation of their aetiology.     

Serologic evidence of arbovirus infections in humans and wild animals in Alaska

Blood samples were collected from humans and several species of free-ranging wild animals in Alaska. Sera were tested for antibody to Jamestown Canyon (JC), snowshoe hare (SSH), Northway (NOR), Klamath (KLA), Sakhalin (SAK), Great Island (GI), and Silverwater (SIL) virus. JC antibody was found in 54% of 121 human, 89% of 97 bison (Bison bison), 51% of 84 Dall sheep (Ovis dalli), 43% of 68 snowshoe hare (Lepus americanus), and 3% of 33 arctic fox (Alopex lagopus) sera. SSH antibody was found in 42% of 121 human, 89% of 97 bison, 41% of 84 Dall sheep, and 65% of 68 snowshoe hare sera. NOR antibody was found in 14% of 121 human, 94% of 97 bison, 84% of 84 Dall sheep, 43% of 69 caribou (Rangifer tarandus), 3% of 68 snowshoe hare, 48% of 64 grizzly bear (Ursus arctos), 3% of 33 arctic fox, and 78% of 27 moose (Alces alces) sera. KLA antibody was found in 5% of 121 human and 40% of 97 bison sera. SAK antibody was found in 2% of 97 bison and 3% of 33 arctic fox sera. GI antibody was found in 1% of 97 bison sera. No SIL antibody was found in any sera tested. Thus the natural host ranges of JC, SSH, NOR, and KLA viruses have been extended by inference from the occurrence of antibody.     

Toxoplasma gondii isolates from free-range chickens from the northeast region of Brazil

The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 152 free-range chickens (Gallus domesticus) from 22 municipalities in 7 northeastern states (Pernambuco, Rio Grande do Norte, Maranh?o, Bahia, Ceará, Sergipe, and Alagoas) of Brazil was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT); 81 (53.3 %) chickens had titers of 1:5 in 26, 1:10 in 9, 1:20 in 4, 1:40 in 1, 1:80 in 6, 1:160 in 6, 1:320 in 13, 1:640 in 6, 1:1,280 in 3, 1:2,560 in 6, and 1:5,120 or higher in 1. Hearts and brains of 81 seropositive chickens were bioassayed individually in mice. Toxoplasma gondii was isolated from 23 chickens with MAT titers of 1:5 or higher; the isolates were designated TgCKBr165-187. Five isolates killed all infected mice. Results indicate widespread contamination of rural environment in Brazil with T. gondii oocysts.     

Serologic evidence of West Nile virus infection in patients with exanthema in Hungary

The presence of WNV in Europe has been well known for decades, although the first human infections and avian outbreaks were diagnosed in Hungary only in 2003. An annual average of 6-8 cases of the neuroinvasive form of WNV infection has been detected in the region since then, but a higher number (17) of WNV associated neuroinvasive disease occurred in 2008. In 2004, a surveillance system was established for monitoring WNV-associated meningo-encephalitis cases in Hungary, but a milder type of illness (with fever, rash and/or influenza like symptoms) is not followed. Fifty-two sera of 45 patients with mild clinical symptoms (fever, exanthema) were tested for anti-WNV antibodies in 2008 in a retrospective study by immunofluorescence test and ELISA. Seven patients had antibodies against WNV, serologic evidence of recent WNV infection was found in 4 out of the 7 patients. Infections could be acquired predominantly in August and in September, which seems to be a risk period for WNV in Hungary. The possibility of a recent WNV infection should be taken into consideration in the occurrence of fever and rush at late summer. Differential diagnosis of exanthematous patients should include WNV serology tests and should be done routinely.     

Serologic survey of West Nile virus in horses from Central-West,Northeast and Southeast Brazil

Since the emergence of West Nile virus (WNV) in North America in 1999, there have been several reports of WNV activity in Central and South American countries. To detect WNV in Brazil, we performed a serological survey of horses from different regions of Brazil using recombinant peptides from domain III of WNV. Positive samples were validated with the neutralisation test. Our results showed that of 79 ELISA-positive horses, nine expressed WNV-specific neutralising antibodies. Eight of the infected horses were from the state of Mato Grosso do Sul and one was from the state of Paraíba. Our results provide additional evidence for the emergence of WNV in Brazil and for its circulation in multiple regions of the country.     

Serologic evidence of influenza A infection in marine mammals of arctic Canada.

A serologic survey of influenza A antibodies was undertaken on 1,611 blood samples from five species of marine mammals collected from Arctic Canada from 1984-98. Sampling was done in 24 locations throughout the Canadian Arctic encompassing Sachs Harbor (72 degrees N, 125 degrees W), Northwest Territories in the west to Loks Land (63 degrees N, 64 degrees W), Nunavut in the east, to Eureka (80 degrees N, 86 degrees W), Nunavut in the north to Sanikiluaq (56 degrees N, 79 degrees W), Nunavut in the south. A competitive ELISA using a monoclonal antibody (Mab) against influenza A nucleoprotein (NP) was used. Five of 418 (1.2%) belugas (Delphinapterus leucas) and 23 of 903 (2.5%) ringed seals (Phoca hispida) were serologically positive. None of the 210 walruses (Odobenus rosmarus rosmarus), 76 narwhals (Monodon monoceros) and four bowhead whales (Balaena mysticetus) had detectable antibodies to influenza A. Positive belugas were identified from communities on southeast Baffin Island while positive ringed seals came from communities in the eastern, western and high Arctic. Virus isolation attempts on lung tissue from a seropositive beluga were unsuccessful. We believe that influenza A infection in marine mammals is sporadic, the infection is probably self-limiting, and it may not be able to be maintained in these animals. Although the predominant hemagglutinin (H) type was not determined and therefore the pathogenicity of the strains to humans is unknown, the hunting and consumption of marine mammals by the Inuit, may put them at risk for influenza A infection.     

Ecological analysis of acari recovered from coprolites from archaeological site of northeast Brazil

Coprolite samples of human and animal origin from the excavations performed at the archaeological site of Furna do Estrago, at Brejo da Madre de Deus in the state of Pernambuco, Brazil and sent to the Paleoparasitology Laboratory at Escola Nacional de Saúde Pública-Fiocruz, Rio de Janeiro, were analyzed for mites. After rehydratation and sedimentation of the coprolites, the alimentary contents and the sediments were examined and the mites collected and prepared in definitive whole mounts, using Hoyer's medium. Mites of the following suborders and orders were recovered: suborder Acaridia; order Gamasida; order Ixodida with the familiy Ixodidae (Ixodes sp. and Amblyomma sp. larvae, scutum, idiosoma, gnathosoma); order Oribatida (Aphelacarus sp., Apolohmannia sp., Eophypochthonius sp., Cosmochthonius sp., Pterobates sp., Poronoticae with pteromorphae not auriculate); order Astigmata with the families Atopomelidae (Chirodiscoides caviae), Anoetidae hypopus, Acaridae (Suidasia pontifica), Glycyphagidae (Blomia tropicalis), Pyroglyphidae (Hirstia passericola); order Actinedida with the family Tarsonemidae (Iponemus radiatae). The present work discusses the possibility of the preservation of the mite groups found up to the present day. We also discuss their relationship with the environment and their importance to present populations.     

Evaluation of three serological tests for the detection of human plague in northeast Brazil.

The passive haemagglutination (PHA) test, enzyme-linked immunosorbent assay (ELISA) and the dot enzyme-immunosorbent assay (DOT-ELISA) were used to detect the levels of IgG antibodies against the Fraction 1 (F1) antigen of Yersinia pestis in sera of plague-infected patients from Northeast Brazil. Twenty three selected PHA-positive sera of subjects with bacteriological confirmation of plague were also positive in the DOT-ELISA but only 19 were detected by the conventional ELISA technique. Another group of 186 serum samples from subjects diagnosed as plague-infected by clinical and epidemiological parameters, but PHA-negative, were screened with DOT-ELISA and 11 gave positive results. The specificity of the assays on the serological detection of plague was confirmed in inhibition tests using purified F1 antigen. These results suggest that DOT-ELISA can be an useful, simple and more sensitive alternative for the serodiagnosis of plague in Northeast Brazil.     

Animal models in ocular toxocariasis

Ocular toxocariasis is a clearly defined disease. However, much remains to be learned concerning the migratory route, ocular changes, diagnosis and treatment. Studies in paratenic hosts have contributed to our understanding and will yield more information. Various experimental animals have been used, such as mice, rabbits, guinea pigs, primates, hamsters and gerbils. Of these, the last appear to be the most appropriate model due to their high susceptibility to ocular infection. Results obtained from different animal models are often not comparable due to the fact that dose and routes of inoculation are diverse. Early stages in the pathogenesis of ocular toxocariasis are manifested by haemorrhages in the anterior chamber and iris, replaced in time by accumulations of white cells. Ocular migration produces an early cell reaction, formed by an infiltration of neutrophils accompanied by vasculitis and retinal microinfarcts. Over a period of time, an increase of macrophages and the distribution of the infiltrates is observed. Later, granulomatous lesions are formed. These do not necessarily contain a larva and their appearance varies in different animal models. Local production of IgE and the presence of specific IgG have been described.