COVID-19-Related Laboratory Analyte Changes and the Relationship Between SARS-CoV-2 and HIV, TB, and HbA1c in South Africa.

We conducted a retrospective analysis on data of all adults tested for SARS-CoV-2 across our laboratory network in South Africa over a 4-month period. Out of 842,197 tests, 11.7% were positive and 88.3% negative. The prevalence of HIV was 6.25 and 6.31% in the SARS-CoV-2-positive and SARS-CoV-2-negative cohort, respectively (p = 0.444). However, the prevalence of HIV-positive individuals in the critical cohort (9.15%) was higher than in the noncritical group (6.24%) (p = 0.011). Active tuberculosis infection was approximately 50% less in SARS-CoV-2-positive than in SARS-CoV-2-negative individuals. The prevalence of uncontrolled diabetes was 3.4 times higher in SARS-CoV-2-positive cases but was not higher in the critical vs. noncritical cases (p = 0.612). The neutrophil-to-lymphocyte ratio, coagulation markers, urea, and cardiac- and liver-related analytes were significantly elevated in the critical compared to noncritical cases. Platelet count and creatinine concentration did not differ significantly between the two groups. These findings do not support increased prevalence of HIV or tuberculosis in individuals with SARS-CoV-2 infection but do suggest an association of increased disease severity with HIV-positive status. Uncontrolled diabetes was positively associated with a significantly higher prevalence of SARS-CoV-2, and our investigation into analyte changes associated with SARS-CoV-2 disease severity supported previous findings of raised inflammatory markers, coagulation markers, liver- and cardiac-related analytes, and urea but not for creatinine and platelet count.

Dengue virus virulence and transmission determinants.

The mechanisms of dengue virus (DENV) pathogenesis are little understood because we have no models of disease; only humans develop symptoms (dengue fever, DF, or dengue hemorrhagic fever, DHF) and research has been limited to studies involving patients. DENV is very diverse: there are four antigenic groups (serotypes) and three to five genetic groups (genotypes) within each serotype. Thus, it has been difficult to evaluate the relative virulence or transmissibility of each DENV genotype; both of these factors are important determinants of epidemiology and their measurement is complex because the natural cycle of this disease involves human-mosquito-human transmission. Although epidemiological and evolutionary studies have pointed to viral factors in determining disease outcome, only recently developed models could prove the importance of specific viral genotypes in causing severe epidemics and their potential to spread to other continents. These new models involve infection of primary human cell cultures, "humanized" mice and field-collected mosquitoes; also, new mathematical models can estimate the impact of viral replication, human immunity and mosquito transmission on epidemic behavior. DENV evolution does not seem to be rapid and the transmission and dispersal of stable, replication-fit genotypes has been more important in the causation of more severe epidemics. Controversy regarding viral determinants of DENV pathogenesis and epidemiology will continue until virulence and transmissibility can be measured under various conditions.

Autologous blood donor screening indicated a lower prevalence of viral hepatitis in East vs West Germany: epidemiological benefit from established health resources.

Prevalence data concerning viral hepatitis and human immunodeficiency virus (HIV) in the general population are usually scarce. We aimed for a large cohort representative of the general population that required little funding. Autologous blood donors are relatively representative of the general population, and are tested for viral hepatitis and HIV in many countries. However, frequently these data are not captured for epidemiologic purposes. We analysed data from well over 35,000 autologous blood donors as recorded in 21 different transfusion centres for anti-hepatitis C virus (HCV), HBsAg and anti-HIV, as well as TPHA if available. We found a lower prevalence of hepatitis B virus and HCV in East vs West Germany, 0.2%vs 0.32% and 0.16%vs 0.32% respectively, which confirms earlier data in smaller cohorts, thus supporting the value of our approach. HIV was too rare to disclose significant differences, 0.01%vs 0.02%. TPHA was higher in East (0.34%) vs West Germany (0.29%) without significant differences. HCV was more frequent in women vs men. Transfusion institutes managing autologous blood donations should be used as a resource for epidemiological data relating to viral hepatitis and HIV, if such testing is performed routinely. This approach generates data relating to the general population with special emphasis on undiagnosed cases.

Swine enteric coronavirus disease: A review of 4 years with porcine epidemic diarrhoea virus and porcine deltacoronavirus in the United States and Canada.

Swine enteric coronaviruses, including porcine epidemic diarrhoea virus (PEDV) and porcine deltacoronavirus (PDCoV), have emerged and spread throughout the North American swine industry over the last four years. These diseases cause significant losses within the pork industry and within the first year after PEDV introduction, approximately 10% of the US herd died due to the disease. Similar to other enteric coronaviruses, such as transmissible gastroenteritis virus (TGEV), these emerging swine enteric coronavirus diseases (SECD) are age-dependent, with high morbidity and mortality in neonatal pigs. Since the introduction of SECD, research has focused on investigating viral pathogenesis through experimental inoculation, increasing maternal antibody for neonatal protection, understanding transmission risks through feed and transportation, and outlining the importance of biosecurity in preventing SECD introduction and spread. A survey of swine professionals conducted for this review revealed that the majority of respondents (75%) believe SECD can be eradicated and that most herds have been successful at long-term elimination of SECD after exposure (80%). However, unique properties of SECD, such as ineffective immunity through parenteral vaccination and a low oral infectious dose, play a major role in management of SECD. This review serves to describe the current knowledge of SECD and the characteristics of these viruses which provide both opportunities and challenges for long-term disease control and potential eradication from the US swine population.

Eyelid microcystic adnexal carcinoma.

Microcystic adnexal carcinoma is an uncommon cutaneous tumor with multiple synonyms. On cursory microscopic examination, the tumor mimics syringoma and other benign skin adnexal tumors. However, the asymmetric, infiltrative growth pattern clearly sets the lesion apart as carcinoma. The tumor is locally aggressive, with recurrences common, but regional metastases are rare. Histogenesis is controversial. Optimal treatment consists of complete surgical excision with clear surgical margins.

Orbital angiolipoma.

Successful resection of an orbital angiolipoma in a 3-year-old child was performed. To our knowledge, this is the first report of angiolipoma in this site.

Molecular phylogeny of Guanarito virus, an emerging arenavirus affecting humans.

The nucleotide sequence of a portion of the nucleocapsid (N) gene of the Guanarito virus prototype strain (INH-95551) has been determined. It was obtained by direct RNA and polymerase chain reaction (PCR) fragment sequencing of the 3' end of the small (S) RNA fragment. A comparison of this 782-nucleotide segment was done with the known homologous gene sequences of five other arenaviruses: Junin, Machupo, Tacaribe, Pichinde, and lymphocytic choriomeningitis (LCM). Phylogenetic analysis of the N gene open reading frame showed that Guanarito virus is genetically distinct from other members of the Arenavirus family, with 32% nucleotide sequence divergence from Junin, 30% from Machupo, 32% from Tacaribe, 41% from Pichinde, and 45% from LCM. Comparison of amino acids encoded by this sequence region indicated a probable antigenic domain (amino acids 55-63) shared among all arenaviruses studied to date. Along with its host restriction and focal distribution, our data support the hypothesis that this virus has been evolving independently in its endemic focus, for some time.

Monoclonal antibodies define antigenic variation in the ID variety of Venezuelan equine encephalitis virus.

Three monoclonal antibodies were generated that are specific for the E2 glycoprotein of Venezuelan equine encephalitis (VEE) virus and have useful reactivities in an enzyme-linked immunosorbent assay (ELISA). Antibody 1A1B-9 distinguished between the IC (epizootic) and ID (enzootic) varieties of VEE virus by ELISA. Clone 7A1A-1 antibody distinguished the Panamanian prototype virus (3880) from Colombian ID isolates by a 500-fold difference in titer by endpoint ELISA, and it detected antigenic variation in ID isolates from southern Colombia and Ecuador. Antibody 7A3A-4 defined a cryptic antigenic site on the latter two isolates. These monoclonal antibodies complement others in identifying VEE isolates by a simple ELISA.

A new genotype of Japanese encephalitis virus from Indonesia.

Primer-extension sequencing of the RNA template of polio, dengue, Rift Valley fever, and Japanese encephalitis (JE) viruses has provided new information on their geographic distribution, origin, and evolution. In a previous study of 46 diverse JE virus strains, we demonstrated the existence of three distinct JE genotypes in Asia. We now report the occurrence of a fourth genotype. In the present study, 19 JE virus isolates, representing various geographic regions of Asia and a 50-year time span, were compared with each other and with Murray Valley encephalitis, West Nile, and Kunjin viruses. Twelve of the JE strains from the Indonesian Archipelago and the Philippines had not been previously examined; the remainder were representatives of the three previously identified genotypes. Two hundred forty nucleotides from the pre-M gene region of the virus were used in these comparisons. Using 12% divergence as a cut-off point, the 19 JE strains fell into four distinct genotypic groups; maximum divergence across the comparison region was 21%. The newly recognized fourth genotype was comprised of five Indonesian isolates that were 7% divergent from the rest of the JE viruses.

Genetic variation of Venezuelan equine encephalitis virus strains of the ID variety in Colombia.

To determine the degree of genetic variation within one serologic group of Venezuelan equine encephalitis virus and the relatedness of viruses with different epidemiologic backgrounds isolated within the same country, virion RNA from 16 isolates belonging to subtype I were compared by RNase T1 oligonucleotide fingerprinting. RNA fingerprints of 12 enzootic isolates showed a large degree of heterogeneity, even though they were serologically indistinguishable. A reference enzootic strain from Colombia showed more genetic relatedness to three epizootic strains isolated in the same country, than to its own serogroup prototype strain isolated in Panama. Thus, genetic relatedness within Venezuelan equine encephalitis strains in Colombia seems to be a function of geography rather than epidemiology.

Molecular evolution of dengue type 2 virus in Thailand.

Dengue is a mosquito-borne viral infection that in recent years has become a major international public health concern. Dengue hemorrhagic fever (DHF), first recognized in Southeast Asia in the 1950s, is today a leading cause of childhood death in many countries. The pathogenesis of this illness is poorly understood, mainly because there are no laboratory or animal models of disease. We have studied the genetic relationships of dengue viruses of serotype 2, one of four antigenically distinct dengue virus groups, to determine if viruses obtained from cases of less severe dengue fever (DF) have distinct evolutionary origins from those obtained from DHF cases. A very large number (73) of virus samples from patients with DF or DHF in two locations in Thailand (Bangkok and Kamphaeng Phet) were compared by sequence analysis of 240 nucleotides from the envelope/nonstructural protein 1 (E/NS1) gene junction of the viral genome. Phylogenetic trees generated with these data have been shown to reflect long-term evolutionary relationships among strains. The results suggest that 1) many different virus variants may circulate simultaneously in Thailand, thus reflecting the quasispecies nature of these RNA viruses, in spite of population immunity; 2) viruses belonging to two previously distinct genotypic groups have been isolated from both DF and DHF cases, supporting the view that they arose from a common progenitor and share the potential to cause severe disease; and 3) viruses associated with the potential to cause DHF segregate into what is now one, large genotypic group and they have evolved independently in Southeast Asia for some time.

Association of Venezuelan equine encephalitis virus subtype IE with two equine epizootics in Mexico.

Two outbreaks of encephalitis consistent with an etiology of Venezuelan equine encephalitis (VEE) virus occurred in equines on the Pacific coast of southern Mexico in 1993 (Chiapas State) and in 1996 (Oaxaca State). In Chiapas, there were 125 cases, of which 63 were fatal and in Oaxaca, there were 32 cases and 12 fatalities. Virus was isolated from two horses from each outbreak, including three brain isolates and one from blood. Virus isolates (93-42124, ISET-Chi93, Oax131, and Oax142) were shown by indirect immunofluorescence, hemagglutination inhibition, monoclonal antibody ELISA, and nucleotide sequencing to be VEE virus, subtype IE, a type previously thought to be equine-avirulent. Genetic characterization and phylogenetic analysis indicated that the outbreak viruses were identical or nearly identical to one another and that they were closely related to equine-avirulent IE strains from Guatemala and the Gulf coast of Mexico. In a plaque-reduction neutralization test, sera collected from healthy horses in Chiapas and Oaxaca reacted significantly better with isolate 93-42124 than with Guatemala IE isolate 68U201, suggesting that subtle genetic changes may have resulted in alteration of neutralization domains. It is not clear whether these differences may also influence equine virulence. However, renewed VEE virus subtype IE activity in Mexico, and its apparent conversion to equine virulence, underscores the need for increased surveillance, additional laboratory and epidemiologic studies in VEE-endemic regions, and possibly new vaccines.

Tolerability of timolol and betaxolol in patients with chronic open-angle glaucoma.

Twenty-four patients with bilateral chronic open-angle glaucoma received three treatments: (1) artificial tears (control) in both eyes, (2) artificial tears in one eye and one drop of timolol (0.05%) in the other, and (3) artificial tears in one eye and one drop of betaxolol (0.05%) in the other. Twelve patients always received the test medication in the left eye and 12 in the right eye. The patients were examined and questioned about ocular symptoms at the time of drug administration and at 1, 5, 30, and 60 minutes. Irritation was noted in five treated eyes after artificial tears, in three after timolol, and in 11 after betaxolol. The incidence of irritation after initial treatment was significantly lower than expected for timolol than for artificial tears or betaxolol (P less than 0.01).

Herpes zoster ophthalmicus associated with delayed retinal thrombophlebitis.

A 58-year-old woman developed typical herpes zoster ophthalmicus associated with delayed retinal thrombophlebitis and subsequent vitreous hemorrhage. Fluorescein angiography confirmed a diagnosis of thrombophlebitis and demonstrated sparing of the arteriolar circulation. The retinopathy cleared spontaneously and visual acuity returned to 6/6 (20/20).

Differential susceptibility of Aedes aegypti to infection by the American and Southeast Asian genotypes of dengue type 2 virus.

Outbreaks of dengue hemorrhagic fever have coincided with the introduction of the Southeast (SE) Asian genotype of dengue type 2 virus in the Western Hemisphere. This introduced genotype appears to be rapidly displacing the indigenous, American genotype of dengue 2 virus throughout the region. These field observations raise the possibility that the SE Asian genotype of dengue 2 is better adapted for vector transmission than its American counterpart. To evaluate this hypothesis, we compared the ability of viral strains of the SE Asian and American genotypes to infect, replicate, and disseminate within vector mosquitoes (Aedes aegypti). Viral strains of the SE Asian genotype tended to infect and disseminate more efficiently in mosquitoes than did variants of the American genotype. These differences, however, were observed solely in field-derived mosquitoes, whereas viral infection rates were virtually identical in the laboratory-adapted Rockefeller colony of Ae. aegypti. Our findings could provide a physiological basis for the contrasting patterns of dengue virus genotype transmission and spread. Such an understanding of functional differences between viral strains and genotypes may ultimately improve surveillance and intervention strategies.

A simple expression for the buffer index of a weak polyprotic acid.

A simple expression for the buffer index of a solution containing a weak polyprotic acid is derived and presented.

Porcine reproductive and respiratory syndrome: NEB-1 PRRSV infection did not potentiate bacterial pathogens.

A 2-phase study was conducted to evaluate the ability of the NEB-1 strain of porcine reproductive and respiratory syndrome virus (PRRSV) to potentiate common bacterial pathogens of swine. In phase I, 25 of 50 4-5-week-old specific-pathogen-free (SPF) pigs were exposed to NEB-1 PRRSV (day 0). Seven days after virus inoculation, 8 groups received 1 of 4 bacterial pathogens: Haemophilus parasuis, Streptococcus suis, Salmonella cholerasuis, and Pasteurella multocida. The ability of NEB-1 PRRSV to produce clinical disease, viremia, neutralizing antibody, gross and microscopic lesions and to potentiate bacterial pathogens was assessed. Response to NEB-1 PRRSV was similar among inoculated pigs; prolonged hyperthermia, lethargy, mild to moderate dyspnea, and cutaneous erythema were consistent clinical signs. No clinical differences were observed in groups after bacterial challenge. Virus was isolated from serum at weekly intervals through the end of the study, and all PRRSV-inoculated pigs had seroconverted by study termination. Two of 5 pigs died in non-PRRSV-inoculated groups challenged with H. parasuis and Streptococcus suis. Mortality in PRRSV-infected pigs was limited to 1 of 5 pigs from the Salmonella cholerasuis-challenged group. Gross lesions were seen in pigs dying after inoculation in H. parasuis- and Streptococcus suis-inoculated groups, in Salmonella cholerasuis- and P. multocida-challenged pigs, and in 1 non-PRRSV-inoculated control pig. Microscopic lesions consisted of mild to moderate proliferative interstitial pneumonia, nonsuppurative myocarditis, lymphoid hyperplasia, and nonsuppurative encephalitis in PRRSV-inoculated pigs. Findings in phase I indicated that NEB-1 PRRSV does not potentiate bacterial disease while inducing consistent clinical signs, viremia, seroconversion, and microscopic lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of bovine parainfluenza-3 virus on phagocytosis and phagosome-lysosome fusion of cultured bovine alveolar macrophages.

Bovine parainfluenza-3 virus (PI-3V) replicated in cultured bovine alveolar macrophages (BAM) in vitro. Cytopathic changes included spindle cell and giant cell formation, diffuse cell lysis, and cellular detachment progressing to total destruction of the monolayer. Direct immunofluorescent microscopy revealed viral antigen in greater than 90% of BAM on post-inoculation day (PID) 3. Virus titers in culture supernatants increased by a factor of 1.6 X 10(6) TCID50 by PID 6. Candida glabrata was phagocytized by a similar proportion of glass-adherent PI-3V-infected and sham-inoculated control BAM. However, when the number of glass-adherent cells available for assay was taken into account (normalization), the percentage of phagocytic PI-3V-infected BAM was significantly lower than that of the control cells at PID 5 and 7 (P less than 0.01). Phagosome-lysosome fusion assays had a marked reduction of fusion activity in PI-3V-infected BAM as compared with that of control BAM. Proportions of infected cells that showed fusion were approximately 50% of that of the control cells at PID 4 and 6 (P less than 0.05). Normalization of these values reduced the fusion rate of PI-3V-infected BAM to 34% of that of control BAM (P less than 0.01).

Production and characterization of VP4/VP7 reassortant swine rotaviruses derived from Gottfried and OSU parental strains.

The ability of viral glycoproteins (VP) VP4/VP7 reassortant swine rotaviruses (RV) to induce cross-neutralizing antibody against parental serotypes was investigated in guinea pigs. Using selective culture conditions, we produced 10 reassortant viruses that contained gene segment 4 of the OSU RV strain and gene segment 9 of the Gottfried RV strain. These reassortant RV grew to high titer in cell culture and were neutralized by monospecific antisera against both parental RV strains. The reassortant RV were chemically inactivated with binary ethylenimine, adjuvanted with aluminum hydroxide, and used to produce antisera in guinea pigs. The hyperimmune antisera had high neutralization titer against both parent RV strains. These results indicate that several of the reassortant RV may be capable of inducing neutralizing antibodies to VP4 and VP7 and may have future use as bivalent vaccine strains.

Comparison of host immune responses to homologous and heterologous type II porcine reproductive and respiratory syndrome virus (PRRSV) challenge in vaccinated and unvaccinated pigs.

Porcine reproductive and respiratory syndrome (PRRS) is a high-consequence animal disease with current vaccines providing limited protection from infection due to the high degree of genetic variation of field PRRS virus. Therefore, understanding host immune responses elicited by different PRRSV strains will facilitate the development of more effective vaccines. Using IngelVac modified live PRRSV vaccine (MLV), its parental strain VR-2332, and the heterologous KS-06-72109 strain (a Kansas isolate of PRRSV), we compared immune responses induced by vaccination and/or PRRSV infection. Our results showed that MLV can provide complete protection from homologous virus (VR-2332) and partial protection from heterologous (KS-06) challenge. The protection was associated with the levels of PRRSV neutralizing antibodies at the time of challenge, with vaccinated pigs having higher titers to VR-2332 compared to KS-06 strain. Challenge strain did not alter the cytokine expression profiles in the serum of vaccinated pigs or subpopulations of T cells. However, higher frequencies of IFN-γ-secreting PBMCs were generated from pigs challenged with heterologous PRRSV in a recall response when PBMCs were re-stimulated with PRRSV. Thus, this study indicates that serum neutralizing antibody titers are associated with PRRSV vaccination-induced protection against homologous and heterologous challenge.