Detection of Zika virus RNA in semen of asymptomatic blood donors.

OBJECTIVES: Zika virus (ZIKV) transmission through semen donation has never been reported but the risk is supported by the detection of ZIKV in semen and the demonstration of ZIKV sexual transmission. The potential impact of ZIKV on assisted reproductive procedures should be evaluated. METHODS: We tested longitudinally collected semen samples provided by asymptomatic blood donors who tested positive for ZIKV RNA in plasma during ZIKV outbreaks in Puerto Rico and Florida in 2016. RESULTS: Five of the 14 (35.7%) asymptomatic blood donors provided semen samples that tested positive for ZIKV RNA, with ZIKV RNA loads ranging from 8.03 × 103 to 2.55 × 106 copies/mL. Plasma collected at the same time as the semen tested negative for ZIKV RNA for most ZIKV RNA-positive semen collections; all corresponding plasma samples tested positive or equivocal for anti-ZIKV IgG antibodies and all except one tested positive for ZIKV IgM antibodies. The rate of detection of ZIKV RNA in semen in asymptomatic donors is not significantly different from the rate previously reported for symptomatic patients. CONCLUSIONS: Our results that show a high percentage of detection of ZIKV RNA in the semen of asymptomatic men confirm that ZIKV is a new threat for reproductive medicine and should have important implications for assisted reproductive technology. We recommend that semen donations from men at risk for ZIKV infection should be tested for ZIKV RNA, regardless of symptoms of ZIKV infection.

Detection of Trypanosoma cruzi DNA in blood by PCR is associated with Chagas cardiomyopathy and disease severity.

BACKGROUND: The significance of detection of Trypanosoma cruzi DNA in blood of antibody-positive patients for risk of development of Chagas heart disease is not well established. The objective of this study was to compare detection of T. cruzi DNA with known clinical and laboratory markers of Chagas cardiomyopathy (CC) severity. METHODS: This is a case-control study nested within a retrospective cohort developed in Brazil to understand the natural history of Chagas disease. The study enrolled 499 T. cruzi seropositive blood donors (SP-BD) and 488 frequency matched seronegative control donors (SN-BD) who had donated between 1996 and 2002, and 101 patients with clinically diagnosed CC. In 2008-2010 all enrolled subjects underwent a health questionnaire, medical examination, electrocardiograms and echocardiograms and polymerase chain reaction (PCR) analyses. A blinded panel of three cardiologists adjudicated the outcome of CC. Trypanosoma cruzi kinetoplast minicircle sequences were amplified by real-time PCR using an assay with a sensitivity of one parasite per 20 mL of blood. All testing was performed on coded samples. RESULTS: Rates of PCR detection of T. cruzi DNA were significantly (P = 0.003) higher in CC patients and SP-BD diagnosed with CC (79/105 [75.2 %]) compared with SP-BD without CC (143/279 [51.3%]). The presence of parasitaemia was significantly associated with known markers of disease progression such as QRS and QT interval duration, lower left ventricular ejection fraction, higher left ventricular index mass, and elevated troponin and NTpro-BNP levels. CONCLUSION: Trypanosoma cruzi PCR positivity is associated with presence and severity of cardiomyopathy, suggesting a direct role of parasite persistence in disease pathogenesis.

Population traits of the burrowing toad Rhinella fernandezae (Gallardo, 1957) (Anura, Bufonidae).

Size distribution, sex ratio and use of burrows of the burrowing toad Rhinella fernandezae were studied in Buenos Aires province, Argentina. Two sites separated by approximately 300 m were studied: one was a road next to a swamp, and the other a garden of a country house located further from the swamp. We identified toad burrows, and individuals were sexed, measured and given an individual mark. Burrows were examined in subsequent months after the first sampling to assess the presence of toads. We found significant differences in the size distribution between areas, being the proportion of juveniles greater at the site next to the swamp where the reproduction of the species was observed. This result may suggest that the site located near to the swamp functions as a source habitat of individuals that migrate to the other site, where recruitment would be very scarce. Sex proportion of adults did not differ from 1:1 in neither the total population nor in each site, suggesting that there was not differential mortality by sex. Some toads changed burrows throughout the study period, but there were not differences in the frequency of change between adults and juveniles.

Population traits of the burrowing toad Rhinella fernandezae (Gallardo, 1957) (Anura, Bufonidae)

Size distribution, sex ratio and use of burrows of the burrowing toad Rhinella fernandezae were studied in Buenos Aires province, Argentina. Two sites separated by approximately 300 m were studied: one was a road next to a swamp, and the other a garden of a country house located further from the swamp. We identified toad burrows, and individuals were sexed, measured and given an individual mark. Burrows were examined in subsequent months after the first sampling to assess the presence of toads. We found significant differences in the size distribution between areas, being the proportion of juveniles greater at the site next to the swamp where the reproduction of the species was observed. This result may suggest that the site located near to the swamp functions as a source habitat of individuals that migrate to the other site, where recruitment would be very scarce. Sex proportion of adults did not differ from 1:1 in neither the total population nor in each site, suggesting that there was not differential mortality by sex. Some toads changed burrows throughout the study period, but there were not differences in the frequency of change between adults and juveniles.

Distribuição de tamanho, razão sexual operacional, e uso de covas do sapo Rhinella fernandezae foram estudados na província de Buenos Aires, Argentina, em dois sítios afastados 300 m. Um deles é uma trilha próxima a um pântano, o outro, um jardim de uma casa rural, mais afastado do pântano. Identificamos as covas dos sapos, e os indivíduos dentro delas foram sexados, medidos e marcados individualmente. As covas foram monitoradas mensalmente, depois da primeira amostragem para avaliar a presença dos sapos. Achamos diferenças na distribuição de tamanhos entres os sítios, sendo a proporção de juvenis maior naquele próximo ao pântano, onde a reprodução da espécie foi observada. O resultado sugere que o sítio próximo ao pântano funciona como um habitat fonte de indivíduos que migram para aquele mais afastado, onde o recrutamento seria escasso. A taxa entre os sexos dos adultos não foi diferente de 1:1 em nenhum dos sítios amostrados, nem na população total, sugerindo que não existe mortalidade diferencial entre machos e fêmeas. Alguns sapos mudaram de cova durante o período do estudo, mas não houve diferenças na freqüência de mudança entre juvenis e adultos.

Population traits of the burrowing toad Rhinella fernandezae (Gallardo, 1957) (Anura, Bufonidae)

Size distribution, sex ratio and use of burrows of the burrowing toad Rhinella fernandezae were studied in Buenos Aires province, Argentina. Two sites separated by approximately 300 m were studied: one was a road next to a swamp, and the other a garden of a country house located further from the swamp. We identified toad burrows, and individuals were sexed, measured and given an individual mark. Burrows were examined in subsequent months after the first sampling to assess the presence of toads. We found significant differences in the size distribution between areas, being the proportion of juveniles greater at the site next to the swamp where the reproduction of the species was observed. This result may suggest that the site located near to the swamp functions as a source habitat of individuals that migrate to the other site, where recruitment would be very scarce. Sex proportion of adults did not differ from 1:1 in neither the total population nor in each site, suggesting that there was not differential mortality by sex. Some toads changed burrows throughout the study period, but there were not differences in the frequency of change between adults and juveniles.

Distribuição de tamanho, razão sexual operacional, e uso de covas do sapo Rhinella fernandezae foram estudados na província de Buenos Aires, Argentina, em dois sítios afastados 300 m. Um deles é uma trilha próxima a um pântano, o outro, um jardim de uma casa rural, mais afastado do pântano. Identificamos as covas dos sapos, e os indivíduos dentro delas foram sexados, medidos e marcados individualmente. As covas foram monitoradas mensalmente, depois da primeira amostragem para avaliar a presença dos sapos. Achamos diferenças na distribuição de tamanhos entres os sítios, sendo a proporção de juvenis maior naquele próximo ao pântano, onde a reprodução da espécie foi observada. O resultado sugere que o sítio próximo ao pântano funciona como um habitat fonte de indivíduos que migram para aquele mais afastado, onde o recrutamento seria escasso. A taxa entre os sexos dos adultos não foi diferente de 1:1 em nenhum dos sítios amostrados, nem na população total, sugerindo que não existe mortalidade diferencial entre machos e fêmeas. Alguns sapos mudaram de cova durante o período do estudo, mas não houve diferenças na freqüência de mudança entre juvenis e adultos.

Spatial and temporal analysis of the distribution of hantavirus pulmonary syndrome in Buenos Aires Province, and its relation to rodent distribution, agricultural and demographic variables.

We studied the spatial and temporal distribution of Hantavirus Pulmonary Syndrome (HPS) cases from 1998 to 2001 in the Buenos Aires Province, Argentina. HPS is a severe viral disease whose natural reservoir are rodents of the subfamily Sigmodontinae (Muridae) and which occurs in many countries of South and North America. We considered two spatial arrangements: cells of 18.5 x 18.5 km(2); and departments, the political subdivisions of the province, as spatial units. We tested the departure from a Poisson distribution of the number of cases per cell and per month with the Variance/Mean index, while the interaction between spatial and temporal clustering was tested by means of the Knox and Mantel tests. We constructed probability maps in which the HPS rates per department were considered Poisson variates according to population, area and the product of population and area. We analysed the relation between rodent distribution, environmental and demographic variables and HPS cases conducting preliminary univariate analysis from which we selected variables to enter in general linearized models. We found that both the spatial and temporal distribution of cases is strongly aggregated. The spatiotemporal interaction appears to be related to a strong seasonality and the existence of particular ecological conditions rather than epidemic transmission of the disease. The main explanatory variables for the distribution of HPS cases among the departments of the Buenos Aires Province were human population, the distribution of the rodent Oxymycterus rufus and evapotranspiration. The last two variables are probably indicators of favourable ecological conditions for the reservoirs, which encompass other variables not taken into account in this study.

Intra-farm variation of rodent infestations on poultry farms of central Argentina.

1. During the summer and winter of 1998 we monitored rodent infestation in the sheds of 9 poultry farms in central Argentina to estimate variation in rodent infestation within farms and its possible association with shed structure and farm design. 2. We observed great heterogeneity in rodent infestations, with a mean variation of 37% in the 'Rodent Infestation Index' (RII; an estimate of rodent density revealed by tracks) between sheds of the same farm. 3. In summer, the group of sheds that showed the highest RII had a higher chicken density than the group of sheds with the lowest RII. Sheds located between other sheds of the same farm showed a lower RII than sheds located beside the perimeter of the farm. 4. Our results support the hypothesis that rodents show habitat selection at both macro (farm) and microhabitat (shed) scales, and that the variables associated with these associations can change according to the scale. 5. Our observation that sheds located beside the perimeter of the farms are prone to rodent invasions reinforces our previous recommendation that farms with an efficient control of vegetation growth around their perimeter would have appreciably lower rodent infestations.

Environmental factors associated with rodent infestations in Argentine poultry farms.

1. Seasonal variations in rodent infestations were studied at poultry farms in central Argentina as well as the environmental factors associated with rodent infestations at poultry farms. 2. During the summer and winter of 1998 rodent infestation was monitored at 10 poultry farms by means of tracking stations, and 21 environmental variables were selected that a priori could be related with the extent of rodent infestation. 3. There was a higher rodent infestation in winter than in summer. 4. Species detected by rodent sightings at the poultry farms included Akodon azarae, Calomys spp. (C. laucha and possibly C. musculinus) and Mus musculus. 5. In summer, rodent infestation was positively associated with the perimeter of the farm, whereas there was an inverse relationship with the maintenance conditions of the sheds. In winter, rodent infestation was positively associated with the percentage of the borders of the farm covered with vegetation, and with the amount of plant cover, especially the amount of plant cover which was above 20 cm in height. 6. There was no significant relationship between rodent infestation and the time lag since the last application of rodenticide (first-generation anticoagulant) at the farms. 7. These results suggest that strategies for controlling rodents based solely on chemical methods may not be good enough for efficient rodent control. Farms which are properly managed, with a better control of vegetation growth at both the perimeter and within the internal area, in addition to a higher maintenance of sheds have appreciably lower rodent infestations.

Distribution of HIV-1 subtypes seen in an AIDS clinic in Sao Paulo City, Brazil.

OBJECTIVE: To determine the distribution of HIV-1 subtypes in Sao Paulo, Brazil. METHODS: Samples were obtained from 80 consecutive HIV-1-infected individuals attending the Immunodeficiency Clinic at the University of Sao Paulo in 1993. Peripheral blood mononuclear cells (PBMC) were separated by Ficoll-Hypaque gradient and a portion was used for routine CD4 counts; the remainder were frozen. PBMC were proteinase-K-digested and DNA-purified by organic extraction. Samples were amplified for the env region of HIV, and envelope sequence subtypes determined by heteroduplex mobility analysis using prototypic subtypes as references. A subset of these were also sequenced through the C2-V3 region of env. RESULTS: A total 69 of 80 samples yielded env polymerase chain reaction product enabling subtype determination; samples that did not amplify were those with low DNA yields. Among 12 injecting drug users (IDU) or sexual partners of IDU, four were typed as clade F and eight as clade B. Forty-three homosexual men or female sexual partners of bisexual men were typed as clade B. The 14 additional cases without known risk factors were typed as clade B. CONCLUSION: These data suggest that subtype F is related to injecting drug use in Brazil.

PIP: Serum samples from 80 consecutive HIV-1-infected individuals presenting to the Immunodeficiency Clinic at the University of Sao Paulo in 1993 were analyzed to determine the distribution of HIV-1 subtypes in the city. Peripheral blood mononuclear cells (PBMC) were separated using Ficoll-Hypaque gradient, a portion was used for routine CD4 counts, and the rest were frozen. PBMC were proteinase-K-digested and DNA-purified by organic extraction. The samples were amplified for the env region of HIV, and envelope sequence subtypes determined by heteroduplex mobility analysis using prototypic subtypes as references. A subset was also sequenced through the C2-V3 region of env. 69 samples yielded env polymerase chain reaction product enabling subtype determination. The samples which did not amplify had low DNA yields. Among 12 IV-drug users or their sex partners, four were typed as clade F and eight as clade B. 43 homosexual men or female sex partners of bisexual men were typed as clade B. The 14 additional cases with no known risk factor were typed as clade B.

Epidemiologic background of blood donors with antibody to human T-cell lymphotropic virus. Transfusion Safety Study Group.

We interviewed 51 blood donors in four major US metropolitan areas subsequently found to have had antibodies to human T-cell lymphotropic virus (anti-HTLV) in late 1984-early 1985. Sixteen donors (31%) reported that they or a sexual contact had a history of blood transfusion. Twelve donors (24%) reported that they or a sexual contact used intravenous drugs. Ten donors (20%) were blacks born in the southeastern US. Four of the male donors (15%) reported homosexual contact. The most common characteristic was an association with Japan or the Caribbean basin (61%). These results show a broader variation of epidemiologic backgrounds than anticipated.

Propuestas para un control ecologico de la fiebre hemorragica Argentina a traves del manejo del habitat. / Proposals for an ecological control of Argentinian hemorrhagic fever by the management of the habitat

En este trabajo se analizo la variacion de las densidades de especies de roedores segun el tipo de cultivo y manejo agricola.Comparando campos de maiz y soja, a termino, se observo que en los primeros la densidad es mayor que en los segundos, mientras que esta es aun menor en los campos de cultivo invernal, excepto durante su rastrojo. Los campos de maiz que fueron pastoreados previamente a su siembra muestran, a termino menor densidad de roedores que los que no fueron pastoreados, mientras que en los campos de soja la siembra con maquina de trigo tiene un efecto similar. El efecto de los distintos cultivos y manejos varia segun la especie de roedor considerada, siendo las del genero Calomys las que muestran mayor variacion. Debido a que dichas especies son las de mayor importancia epidemiologica, se sugiere, como una primera aproximacion al control ecologico de la FHA, la siembra de soja en lugar de maiz en el area endemica y zonas aledanas, asi como el pastoreo intensivo de los campos previamente a la siembra

Propuestas para un control ecologico de la fiebre hemorragica Argentina a traves del manejo del habitat. / Proposals for an ecological control of Argentinian hemorrhagic fever by the management of the habitat

En este trabajo se analizo la variacion de las densidades de especies de roedores segun el tipo de cultivo y manejo agricola.Comparando campos de maiz y soja, a termino, se observo que en los primeros la densidad es mayor que en los segundos, mientras que esta es aun menor en los campos de cultivo invernal, excepto durante su rastrojo. Los campos de maiz que fueron pastoreados previamente a su siembra muestran, a termino menor densidad de roedores que los que no fueron pastoreados, mientras que en los campos de soja la siembra con maquina de trigo tiene un efecto similar. El efecto de los distintos cultivos y manejos varia segun la especie de roedor considerada, siendo las del genero Calomys las que muestran mayor variacion. Debido a que dichas especies son las de mayor importancia epidemiologica, se sugiere, como una primera aproximacion al control ecologico de la FHA, la siembra de soja en lugar de maiz en el area endemica y zonas aledanas, asi como el pastoreo intensivo de los campos previamente a la siembra