A psychosocial risk assessment model (PRAM) for use with pregnant and postpartum women in primary care settings.

Recognition of high rates of mental health morbidity and mortality that affect women during the perinatal period has prompted the development of psychosocial risk assessment programs. Designed to identify women, at risk, during routine health checks and delivered by primary care health service providers, these fit within a primary prevention and early intervention strategic approach to the reduction of perinatal mental illness and reflect an integrated approach to perinatal health services delivery. This paper describes the development and use of the psychosocial risk assessment model (PRAM) at the Royal Hospital for Women in Sydney, Australia. Data is presented on 2,142 women who attended the Antenatal Midwives Clinic between 2002 and 2005. The PRAM guides primary care staff to quickly identify women experiencing emotional distress and/or psychosocial problems during pregnancy or postnatal checks. Measures used in pregnancy are the symptom-based Edinburgh Depression Scale and the psychosocial risk-based Antenatal Risk Questionnaire. In postnatal setting the Postnatal Risk Questionnaire is used. Scores can be used to compute a Psychosocial Risk Index (PRI) to guide individualized care planning, define needs for referral and classify groups for clinical and research purposes. Based on the PRI, among 2,142 women assessed in pregnancy 70.6% were classified as low/no risk (no interventions indicated currently), 24.1% as medium risk (in need of monitoring), and 5.3% as high risk (complex). The PRAM offers a conceptual framework, methods and measures for brief psychosocial assessment with clinical and research applications. Postpartum follow up studies of women assessed during pregnancy have commenced. Randomized controlled trials and cross-cultural studies are now indicated to strengthen the evidence base for the model.

Combination of antiviral immunotoxin and ganciclovir or cidofovir for the treatment of murine cytomegalovirus infections.

The effects of two anti-murine cytomegalovirus (MCMV) immunotoxins used in combination with ganciclovir (GCV) or cidofovir (HPMPC) against MCMV were determined in vitro and in mice. The inhibitors were added to cell cultures 24 or 48 h after MCMV adsorption so as to not affect the initial infection rate. The immunotoxins (0.63, 1.25 and 2.5 micrograms/ml) combined with GCV (1.25, 2.5 and 5 microM) or HPMPC (0.03, 0.06 and 0.12 microM) caused synergistic inhibition of virus yield in C127I cells at most of the combinations tested. No toxic effect on cell growth in culture was observed at these immunotoxin/drug combinations. The effects of immunotoxin and GCV treatment were studied further in MCMV-infected severe combined immunodeficient (SCID) mice. Immunotoxin (1 mg/kg per day) given by intraperitoneal (i.p.) injection on days 1, 4 and 7 of the infection did not extend the mean day to death compared with the placebo group. Once daily i.p. treatment with GCV (50 mg/kg per day) for days starting at 24 h after virus inoculation extended survival time almost 11 days. The combination of immunotoxin plus GCV was better than GCV alone, extending the mean day to death an additional 2 to 3 days, which is suggestive of a synergistic effect.

Selective cytotoxicity of ricin A chain immunotoxins towards murine cytomegalovirus-infected cells.

Immunotoxins were constructed by linking immunoglobulins specific for murine cytomegalovirus (MCMV) to deglycosylated ricin A chain. Toxicities toward MCMV-infected and uninfected cells were determined by measuring the inhibition of protein synthesis following a 48-h exposure to immunotoxins commencing 24 h after infection. The 50% inhibitory concentrations ranged from 0.4 to 4 micrograms/ml for infected cells and from 22 to 120 micrograms/ml for uninfected cells. Selectivity indices ranged from 30 to 157. Control immunotoxins, which were constructed identically except that the immunoglobulin moiety had no specificity toward MCMV antigens, had 50% inhibitory concentrations of 50 and 100 micrograms/ml toward infected and uninfected cells, respectively.

Selective cytotoxicity towards cytomegalovirus-infected cells by immunotoxins consisting of gelonin linked to anti-cytomegalovirus antibody.

An immunotoxin specific for cells infected with human cytomegalovirus (HCMV) was constructed by attaching the ribosome-inactivating enzyme, gelonin, through a disulfide linkage to polyclonal human immunoglobulin (IgG). In uninfected cells, there was no difference between [35S]methionine incorporation in untreated cultures and those treated with immunotoxin at 100 micrograms/ml. In HCMV-infected cells, there was a significant decrease in [35S]methionine incorporation in the immunotoxin-treated cultures, suggesting a selective cytotoxic effect on the virus-infected cells. An immunotoxin specific for murine cytomegalovirus (MCMV) was prepared by linking gelonin to polyclonal anti-MCMV IgG. Using this same parameter for assay of cytotoxicity, the anti-MCMV immunotoxin had a 50% cytotoxic concentration of 35 micrograms/ml in MCMV-infected cells and greater than 200 micrograms/ml in uninfected cells. MCMV yields measured at 7 days postinoculation were reduced by 2 log10 in cultures treated with immunotoxin at 20 micrograms/ml at 1 day postinoculation. These data suggest immunotoxins may have potential for eliminating CMV-infected cells from the host.

Effects of monoclonal antibody combined with ganciclovir or (S)-1-[3-hydroxy-(2-phosphonylmethoxy)-propyl]cytosine against murine cytomegalovirus infections in cell culture and in severe combined immunodeficient mice.

The effects of monoclonal antibody used in combination with ganciclovir (GCV) or (S)-1-[3-hydroxy-(2-phosphonylmethoxy)propyl]cytosine (HPMPC) against murine cytomegalovirus (MCMV) were determined in vitro and in vivo, in mice. The antibody and drug were added to cell cultures 24 h after MCMV adsorption so as not to affect the initial infection rate. The antibody (at 1.25-20 micrograms/ml) combined with GCV (0.3-5 microM) or HPMPC (0.008-0.125 microM) caused synergistic inhibition of virus yield in C127I cells. No toxic effect on cell growth in culture was observed at these antibody/drug combinations. The effects of antibody and GCV treatments were studied in MCMV-infected severe combined immunodeficient (SCID) mice. Antibody treatments (2.5 mg/kg/day) given by intraperitoneal injection every 3 days starting 24 h after virus inoculation extended survival time by 1 day relative to placebo-treated animals. Once daily, intraperitoneal treatments with GCV (25 and 50 mg/kg/day) for 7 days starting at 24 h after virus inoculation extended survival time 9-11 days. The combination of antibody plus GCV was only slightly better than GCV alone, indicating an additive interaction.

Antiviral activities of nucleosides and nucleotides against wild-type and drug-resistant strains of murine cytomegalovirus.

Resistance of human cytomegalovirus to approved antiviral drugs is becoming a problem of increasing concern. In order to further study drug resistance in a related virus, strains of murine cytomegalovirus (MCMV) have been prepared in vitro by extensive adaptation of the virus to increasingly higher concentrations of either ganciclovir, foscarnet, or (S)-9-(3-hydroxy-2-[phosphonylmethoxy]propyl)cytosine (HPMPC). Plaque reduction 50% effective concentrations (EC50) for the above inhibitors increased 9-, 7-, and 23-fold, respectively (against the corresponding virus), compared to wild-type MCMV. Each virus was then evaluated against other known anti-MCMV agents to determine cross-resistance patterns. These compounds included 3-hydroxy-phosphonylmethoxypropyl derivatives of adenine (HPMPA) and guanine (HPMPG), 2-phosphonylmethoxyethyl derivatives of adenine (PMEA) and 2,6-diaminopurine (PMEDAP), cyclobutylguanine, acyclovir, and the methylene phosphonate derivatives of acyclovir (SR3722) and ganciclovir (SR3773). The ganciclovir-resistant MCMV was cross-resistant to foscarnet, HPMPA, HPMPC, HPMPG, SR3722, and SR3773. The foscarnet-resistant virus was also resistant to acyclovir, PMEA, PMEDAP, SR3722, and SR3773. The HPMPC-resistant MCMV was cross-resistant to HPMPA, HPMPG, and SR3773. Changes in susceptibility were from 3- to 22-fold relative to the wild-type virus. Virus yield reduction data correlated with the plaque assay results. Only cyclobutylguanine was approximately equally active against wild-type and the three drug-resistant MCMVs. The patterns of cross-resistance correlated with resistance seen in human cytomegalovirus strains expressing altered DNA polymerase function. The GCV-resistant and HPMPC-resistant viruses were markedly attenuated in their ability to kill severe combined immunodeficient mice.

Treatment of lethal Pichinde virus infections in weanling LVG/Lak hamsters with ribavirin, ribamidine, selenazofurin, and ampligen.

A lethal Pichinde (An 4763 strain) virus infection was produced in 3-week-old random-bred Golden Syrian (LVG/Lak strain) hamsters inoculated intraperitoneally with virus, causing mortality in 6-9 days. High virus titers (> or = 10(7.5) cell culture infectious doses/g) were present in visceral organs, serum, brain and salivary glands near the time of death. Intraperitoneal treatments with ribavirin (10 and 32 mg/kg) and ribamidine (32, 100, and 320 mg/kg) for 10 days starting 24 h after virus challenge significantly decreased mortality and reduced virus titers by 100- to > 10,000-fold in liver, spleen, brain, and serum. Serum alanine aminotransferase (an indicator of liver damage) was also reduced in animals treated with the two compounds (ribavirin at 32 mg/kg; ribamidine at 100 and 320 mg/kg). Intraperitoneal selenazofurin (1-100 mg/kg per day for 10 days) and ampligen (0.5 and 5 mg/kg every other day for 5 injections) treatments provided neither protection from the lethal infection nor increased mean survival times. In fact, selenazofurin was overtly toxic, causing death of uninfected hamsters at 32 and 100 mg/kg. The random-bred LVG/Lak hamster appears to be a viable and cost-effective model for evaluating new therapies for arenavirus infections.

Antiviral immunotoxins: antibody-mediated delivery of gelonin inhibits Pichinde virus replication in vitro.

Immunotoxins were produced and evaluated for antiviral activity against Pichinde virus, a member of the family Arenaviridae. Immunoglobulins were conjugated to the ribosome-inactivating protein, gelonin, through a disulfide linkage to form the immunotoxins. Immunotoxins were produced utilizing monoclonal antibodies, immunoglobulin-binding proteins and hyperimmune sera. An immunotoxin consisting of hyperimmune rabbit sera conjugated with gelonin displayed strong antiviral activity against Pichinde virus, as did a protein G-gelonin indirect immunotoxin in combination with nonconjugated hyperimmune sera. Hyperimmune rabbit sera conjugated with gelonin caused no detectable cytotoxicity in non-infected Vero cells as measured by [3H]leucine incorporation. The 50% effective dose for the immunotoxin was 0.018 microM compared with 86 microM for ribavirin.

A newly developed immunofluorescent assay for determining the Pichinde virus-inhibitory effects of selected nucleoside analogues.

An immunofluorescent assay (IFA) for Pichinde virus (PCV), a member of the family Arenaviridae, was developed for antiviral drug assays against the virus. The assay was performed by adding fluorescein-labeled anti-PCV monoclonal antibody to virus-infected cells at 24 h after the initial infection and counting the infected cells with an epifluorescence microscope. The average 50% effective dose (ED50) for a series of nucleoside analogues tested against PCV using this IFA was: 2-beta-D-ribofuranosylselenazole-4-carboxamide (selenazofurin), less than 1.0 microgram/ml; 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide (ribavirin), 6.0 micrograms/ml; ammonium 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide- 5'-phosphate hydrate (ribavirin-5'-monophosphate), 15.8 micrograms/ml; ammonium 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide-5'-hemisuccinate (ribavirin-5'-hemisuccinate), 14.7 micrograms/ml; ammonium 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide-5'-(2,3- dimethyl)hemisuccinate [ribavirin-5'-(2,3-dimethyl)hemisuccinate], 213.5 micrograms/ml; 4-hydroxy-1-beta-D-ribofuranosyl-2-pyridone (3-deazauridine), 5.2 micrograms/ml; and (S)-9-(2,3-dihydroxypropyl)adenine, ([S]-DHPA), 471.0 micrograms/ml. In comparison, the ED50 of ribavirin using inhibition of marginal PCV-induced cytopathogenic effect after 12 days was 6.0 micrograms/ml and using plaque reduction after 5 days was 2.5 micrograms/ml, indicating that this IFA was of comparable sensitivity to these other tests.

In vitro and in vivo Phlebovirus inhibition by ribavirin.

Ribavirin (1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide) was markedly inhibitory in vitro to Adames and Balliet strains of Punta Toro virus (PTV), a Phlebovirus related to Rift Valley fever and sandfly fever viruses. By using inhibition of viral cytopathic effect in LLC-MK2 cells with both virus strains, the 50% effective dose was 4 to 10 micrograms/ml and the virus rating was 1.3. The Adames strain of PTV infection in mice was established for evaluation of the in vivo antiviral efficacy of ribavirin. The drug was administered subcutaneously (s.c.) twice daily for 5 to 7 days beginning 4 h pre-virus inoculation, 24 h post-virus inoculation, or 36 h post-virus inoculation, with increased survivors, reduced hepatic icterus, reduction of serum glutamic oxalic acid transaminase and serum glutamic pyruvic acid transaminase, and inhibition of infectious virus from sera and livers of infected mice. The minimum effective dose was 4.7 mg/kg per day, with a maximum tolerated dose of 75 mg/kg per day. When the same treatment schedule beginning 4 h pre-virus inoculation, 4 h post-virus inoculation, or 24 h post-virus inoculation was used, orally administered ribavirin was effective at doses as low as 6.3 mg/kg per day. Single s.c. ribavirin treatments at doses of 175 to 700 mg/kg administered from 4 to 48 h post-virus inoculation were also effective. No effect was seen when ribavirin was administered s.c. to mice infected intracerebrally with the PTV strain Balliet, even though treatment was begun 36 h before virus exposure.

Other viruses with etiologic roles in childhood gastroenteritis.

Rotaviruses and Norwalk-like viruses are the two groups of viruses most frequently associated with gastroenteritis, but as outlined in this review several other viral agents have also been associated with acute gastroenteritis. The gastroenteritis viruses are generally fastidious, and thus traditional cell culture isolation and detection procedures are not applicable; therefore electron microscopy and immunoelectron microscopy remain among the most powerful techniques for studying these viruses. The in vitro cultivation of these viral agents will facilitate the development of diagnostic reagents and the development and evaluation of vaccines. The main need in this area is for suitable cell culture systems for isolating and growing the candidate gastroenteritis viruses.

Enzyme-linked immunosorbent assay, using monoclonal antibody, to detect enterotoxic Escherichia coli K99 antigen in feces of dairy calves.

A modified, double-antibody, enzyme-linked immunosorbent assay (ELISA) was developed to detect the K99 pilus antigen of enterotoxic Escherichia coli (ETEC) in feces of calves. Extremely high positive to negative ratios (greater than 200) were obtained by using monoclonal antisera as the primary antibody. Strong positive reactions were obtained with strains of E coli known to produce the K99 antigen; however, non-enteropathogenic E coli (strains not producing the K99 antigen), Salmonella, Proteus, Klebsiella, Pseudomonas, Staphylococcus, Streptococcus, and rotavirus produced negative results. Seventy-five fecal samples, 8 from healthy calves and 67 from calves with neonatal calf diarrhea were examined with the K99 ELISA for the presence of ETEC. Rotavirus test and fecal culture results were available on feces from calves with diarrhea and were used with the K99 ELISA results to determine the specific cause of the disease. Enterotoxic E coli was the predominant agent detected in the feces of 29 diarrheal calves less than 5 days of age. Mixed infections of rotavirus and ETEC were also common in these calves, but rotavirus infections alone were not detected. In 38 calves greater than or equal to 5 days, rotavirus was detected without ETEC. Of these calves, only 2 produced positive tests with the K99 ELISA. Salmonella sp and Proteus sp were detected from 5 of 67 calves with diarrhea.

Reovirus removal and inactivation by slow-rate sand filtration.

Laboratory column studies were conducted at the Utah Water Research Laboratory, Logan, Utah, to evaluate reovirus removal from drinking water supplies by slow-rate sand filtration (SSF). Columns, constructed to simulate a full-scale SSF field operation, were inoculated with reovirus at ca. 1,000-times-greater concentrations than those typically found in domestic sewage. Reovirus removal and inactivation were investigated as functions of filter maturity and other filter sand characteristics. Reovirus removal studies demonstrated that the SSF process is capable of reducing reovirus in influent water by a minimum of 4 log concentration units under certain conditions of water quality, flow rate, and sand bed construction. Infectious reovirus was not detected in effluent samples from any of the sand beds studied, after inoculation of the SSF columns; therefore, removal efficiencies were not affected significantly by characteristics, including age, of the two filter sands evaluated. Studies conducted with radioactively labeled reovirus demonstrated that reovirus removed from influent water was distributed throughout the entire length of the filter beds. Concentrations of reovirus in the filter sands decreased with increasing bed depth. The greatest removal occurred in the top few centimeters of all sand beds. No infectious reovirus could be detected in clean or mature sand bed media, indicating that reoviruses were inactivated in the filter.

Effects of folic acid malnutrition on rotaviral infection in mice.

A study was undertaken to determine if dietary deficiencies of folic acid would influence rotaviral diarrheal disease in infant mice. Female mice were fed diets containing essentially no folic acid, 25% of a normal quantity of folic acid, or a normally recommended quantity of folic acid, beginning at time of breeding and continuing through periods of gestation and lactation. Two-day-old infants from these dams were exposed to purified murine rotavirus or to sterile virus diluent and the severity of the rotaviral infection monitored. Infants from the low folic acid group had significantly lower folate levels in their livers, indicating a deficiency was achieved, and developed more severe disease manifestations than those infants from the dams receiving the normal folic acid levels in their diet. The infection enhancement was seen as increased incidences of diarrhea and a significantly greater number of mice exhibiting high intestinal rotaviral antigen titers. Serum rotavirus antibody titers were below detectable levels in a significant number of these same infants.

Influence of malnutrition and alterations in dietary protein on murine rotaviral disease.

The possible correlation between malnutrition and degree of severity of rotavirus-associated infantile diarrhea which appears to occur in human populations was studied using a mouse model. To determine the effects of general malnutrition or altered levels of dietary protein, female mice were fed throughout pregnancy and infection periods with diets diluted with 0, 300, or 600 g glucose/kg, designated as normal nutrient to calorie ratio (N/C) diet, 70% N/C diet, or 40% N/C diet or with diets containing 75, 150, or 300 g casein/kg, as low-, normal-, or high-protein diets. Murine rotavirus was given by gavage to the 2-day-old offspring of these dams, and the extent of infection determined. Marked increases in severity of diarrheal disease were seen in the infants from dams receiving the 40 and 70% N/C diets and the low-protein diet. Severity of infection was seen as increased deaths, reduced weight gain, and increased passage of diarrheic feces. Intestinal viral levels and intestinal diarrhea scores did not vary appreciably. Serum interferon remained below detectable limits throughout the studies, but serum antibody was determined in dams 30 days post-virus exposure. The latter titers were lower in the infected mice from dams fed the 40 and 70% N/C diets, but were essentially the same in all the protein diet groups. Cross-fostering was done using the 40 and 100% N/C diets, wherein mice from dams fed either diet were placed on mothers fed the opposite diet. Increased severity of infection was again seen when the virus was given 2 days after the exchange, although the greatest infection occurred in animals from dams fed 40% N/C diet which were then fostered by other similarly fed dams. The increased host sensitivity to the rotaviral infection appeared to be a result of both pre- and postnatal dietary effects.

Aerosol stability of infectious and potentially infectious reovirus particles.

The aerosol stability of two particle forms, infectious and potentially infectious, of reovirus were examined under static conditions for a range of relative humidities at 21 and 24 degrees C. Virus aerosolization efficiency was determined for two methods of dissemination: Collison nebulizer and Chicago atomizer. Suspensions of Bacillus subtilis var. niger spores were added to reovirus preparations that included both particle forms and disseminated into a dynamic aerosol toroid to estimate the physical decay of the aerosols. At 90 to 100% relative humidity, both reovirus particle forms showed less than 10-fold loss of infectivity after 12 h of aging. At lower relative humidities the aerosol decay curve showed rapid initial decay followed by a markedly lower decay rate. Our findings reveal that reovirus particles are relatively stable in the airborne state.

Protamine precipitation of two reovirus particle types from polluted waters.

Two forms of virus particle are released from reovirus-infected cell cultures, infectious reovirus and potentially infectious reovirus (PIV). PIV particle forms have a complete outer coat and are not infectious until the outer coat is altered or removed. The PIV concentration in polluted waters, however, has not been determined. Protamine sulfate precipitation, using 0.25% fetal bovine serum and 0.005% protamine sulfate for the first precipitation of the sample and 0.0025% for the second, was employed to concentrate infectious reovirus and PIV from water and sewage. Infectious reovirus and PIV particles were concentrated over 500-fold from river water inoculated with virus, and virus recoveries of between 80 and 100% were achieved. Virus precipitates stored at -20 degrees C as a protamine-virus concentrate showed a 5% loss of PIV after 14 days. Virus preparations were assayed, before and after treatment, with 200 micrograms of chymotrypsin per ml, using a fluorescent-antibody procedure. Protamine sulfate precipitation and fluorescent-antibody detection are effective ways to recover and assay reoviruses present in raw sewage.

Evaluation of cell lines and immunofluorescence and plaque assay procedures for quantifying reoviruses in sewage.

Twelve continuous cell lines were tested to determine their sensitivity to reovirus types 1, 2, and 3 isolated from sewage. Madin-Darby bovine kidney (MDBK), rhesus monkey kidney (LLC-MK2), and human embryonic intestinal (intestinal 407) cells were most sensitive, respectively. In a similar study, MDBK cells were more sensitive than LLC-MK2 and Buffalo green monkey kidney (BGM) cells to sewage-isolated, protamine-precipitated reoviruses which had not been serotyped and had no previous cell contact. Sewage-isolated, protamine-precipitated reoviruses were also used in conjunction with MDBK cells in a comparative evaluation of immunofluorescent cell count and plaque assay procedures. The immunofluorescence assay is more sensitive and more rapid than the plaque assay. Reoviruses in excess of 10(4)/liter of raw sewage were detected by the immunofluorescent cell count assay.

Inhibition of rotaviruses by selected antiviral substances: mechanisms of viral inhibition and in vivo activity.

Several RNA virus inhibitors were evaluated against simian (SA11) rotavirus infections in vitro and murine rotavirus gastroenteritis in vivo. Test compounds included 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide (ribavirin), 3-deazaguanine (3-DG), 3-deazauridine, and 9-(S)-(2,3-dihydroxypropyl)adenine [(S)-DHPA]. All drugs inhibited total infectious SA11 virus yields in MA-104 cells. Ribavirin, 3-DG, and (S)-DHPA affected [3H]uridine uptake into uninfected MA-104 cells in both the acid-soluble and -insoluble fractions. All drugs reduced the levels of dense (precursor) and light (complete) SA11 particle yields compared with control but did not alter the relative amounts of dense compared with light particles, suggesting that the agents did not interfere with virus assembly. Ribavirin and 3-DG inhibited SA11 polypeptide synthesis, as determined by polyacrylamide gel electrophoresis studies. None of the agents or mono- and triphosphate derivatives of ribavirin inhibited SA11 RNA polymerase activity. In murine rotavirus studies, oral therapy with ribavirin-2',3',5'-triacetate and (S)-DHPA increased mean survival time, but no increase in survivor rate was observed. 3-DG- and (S)-DHPA-treated mice had a more rapid weight gain than controls, suggesting a probable lessening of the severity of the disease.

Inhibition of bluetongue and Colorado tick fever orbiviruses by selected antiviral substances.

The effects of four ribonucleic acid virus inhibitors were evaluated in cell cultures and in mice to determine inhibitory effects against bluetongue virus and Colorado tick fever virus (CTFV). Test compounds included 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide (ribavirin), 3-deazaguanine, 3-deazauridine, and 9-(S)-(2,3-dihydroxypropyl)adenine. Ribavirin-2',3',5'-triacetate (ribavirin triacetate) was evaluated in vivo against CTFV. Inhibition of cytopathic effect and plaque reduction were used to evaluate antiviral activity. In cytopathic effect inhibition studies, bluetongue virus was markedly inhibited by 3-deazaguanine and 3-deazauridine in Vero cells with moderate inhibition by the other agents. Ribavirin and 3-deazaguanine markedly inhibited CTFV in MA-104 cells, 3-deazauridine was slightly less active, and 9-(S)-(2,3-dihydroxypropyl)adenine was negative. Ribavirin was less effective in Vero cells against CTFV. When mice were inoculated intracerebrally with CTFV and treated by a single intracerebral injection with drug, ribavirin triacetate increased the number of survivors, 3-deazaguanine increased mean survival time, and ribavirin was negative. Intraperitoneal treatment of infected mice with ribavirin triacetate for 1 week significantly increased the number of survivors and mean survival time, providing strong evidence that the agent is active across the blood-brain barrier.