Viral transmission

The individual responsiveness to desmopressin is consistent, and a test dose administered at the time of diagnosis or prior to therapy is the best predictor of response. Generally, DDAVP is more effective in vWD than in hemophilia patients, with an average 30% to 50% increase in vWF and factor VIII levels. In patients with an adequate response, desmopressin is first-line therapy because it allows for once-daily administration (elevates plasma levels for 8-10 hours), does not pose a threat in terms of viral transmission, and the cost is substantially less than that of the plasma-derived products. Fibrinolysis inhibitors (50-60 mg/kg of aminocapriotic acid every 4—6 hours or trenex-amic acid 10-15 mg/kg every 8-12 hours) and OCs are used successfully in the management of epistaxis and menorrhagia or as adjuvant treatments. 

Acute HIV Infection Diagnosis of acute HIV infection is difficult, since many patients are asymptomatic, or have nonspecific clinical symptoms similar to other common respiratory infections. If acute HIV infection is suspected, HIV antibody tests and a plasma HIV RNA concentration should be obtained. A clear diagnosis is made when an HIV antibody test is negative and the plasma HIV RNA concentration is high. There are limited outcomes data for treating acutely infected patients. Treatment of acute infection can decrease the severity of acute disease and decrease the viral set point this may decrease progression rates and reduce the rate of viral transmission.18-22 Limitations include an increased risk of chronic drug-induced toxicides and the development of viral resistance. 

Unutmaz D, Littman DR. Expression pattern of HIV-1 coreceptors on T cells implications for viral transmission and lymphocyte homing. Proc Natl Acad Sci US A 1997 94 1615-1618. 

Chronic transfusion is indicated to prevent stroke and stroke recurrence in children. Transfusion frequency is usually every 3 to 4 weeks and should be adjusted to maintain HbS of less than 30% of total hemoglobin. The optimal duration is unknown. Risks include alloimmunization, hyperviscosity, viral transmission (requiring hepatitis A and B vaccination), volume and iron overload, and transfusion reactions. 

E Role in therapy Antihemophilic factor is indicated for the treatment of bleeding episodes or perioperative treatment in patients with hemophilia A. Prophylactic use has also been advocated for the prevention and/or reduction of bleeding episodes. The largest issue in treatment with antihemophilic factor is the choice of formulations because of the relative risk of viral transmission. Recombinant factor VIII has the lowest risk of transmission of blood-borne viruses, but its use may be limited due to cost and availability. 

Recombinant-derived and monoclonal antibody-prepared formulations have been developed to reduce the danger of viral transmission. However, recombinant-derived and monoclonal antibody-purified formulations do not contain the large multi-mers of the von Willebrand factor and are not indicated for treatment of von WiUebrand s disease. 

Fractionation techniques have made it possible to recover active o -antitrypsin from blood. Use of this product for intravenous replacement therapy in deficient individuals has shown that it is possible to increase levels in the serum to those of PISZ heterozygotes who experience no increase in pulmonary disease over the general population. Pulmonary lavage of patients transfused with this product showed that functional (Xj-antitrypsin reaches the alveolar structures. The Food and Drug Administration has approved weekly administration of purified serum-derived oq-antitrypsin to PIZZ and PI null individuals with pulmonary disease. Although serum levels of oq-antitrypsin increase to those believed to be protective, it has not been possible to show clinical improvement. Furthermore, viral transmission via blood products is a significant risk factor. 

Approximately 90% of the population is infected with herpes simplex virus type 1 (HSV-1), and at least 10% with HSV-2 (Nahmias and Roizman, 1973 Whitley, 1997). Humans are the only natural reservoir for this infection, and no vectors are involved in transmission of this virus (Stanberry et al., 2004). HSV-1 primary infection occurs mainly in childhood, and HSV-2 infection occurs predominantly in sexually active adolescents and young adults. Aerosols or close contact are the primary mechanisms of viral transmission. Although transmitted by different routes and involving different parts of the body, these two viral subtypes have similar epidemiology and clinical manifestation. 

The phenomenon of viral adsorption to various surfaces was extensively studied from an environmental standpoint as reviewed by Daniels (14) and Gerba (15) for prevention of various waterborne viral transmissions. The problem of virus removal from complex protein solutions is very different from that of sewage and drinking water treatment processes because most protein molecules compete for the active sites of the adsorbents. Hence, both the adsorption rate and capacity diminish in the presence of protein molecules (16). It is the intention of this paper to demonstrate and to compare the antiviral activity of a surface-bonded QAC in aqueous solutions against 2 model viruses with and without the presence of proteins. The efficacy of the accepted antiviral thermo-inactivation was compared with the viral inactivation method by the surface-bonded QAC treatment. Beta-lactamase was used as a thermolabile model protein (17), and bacteriophage T2 and herpes simplex virus type 1 (HSV-1, an enveloped animal virus) were used as model hydrophilic and hydrophobic viruses to test these chemical inactivation methods. 

The dose of desmopressin for von WiUebrand disease is identical to that used in the treatment of mild factor VIII deficiency, 0.3 mcg/kg diluted in 30 to 50 mL of normal saline and given intravenously over 15 to 30 minutes. In general, patients with von WiUebrand disease have a better response to desmopressin than those with hemophilia, with an average three- to fivefold rise in von WiUebrand factor and factor VIII levels. These levels remain elevated for about 6 to 8 hours. The response to desmopressin in a given patient is usuaUy consistent, and a trial of desmopressin should establish if the medication is likely to be effective for the individual. Desmopressin is preferable to the use of plasma-derived products for patients who have an adequate response because desmopressin does not carry a risk of viral transmission. An added benefit is that desmopressin is substantiaUy less costly than the plasma-derived products. (For a discussion of the side effects of desmopressin, see the section on the treatment of hemophUia A.)... 

Recombinant factor Vni has a low risk of viral transmission. Adverse effects of these prodncts inclnde metallic taste, mild dizziness, mild rash, burning at the infusion site, and a small drop in blood pressure. ... 

The major concern associated with the use of concentrated clotting factors is the risk of viral transmission (primarily HIV and hepatitis B). This fear has somewhat attenuated the use of concentrated plasma fractions, even In diseases such as hemophilia. Ultrapure factor VIII concentrates produced using recombinant DMA technology have been approved for use. Frequently, however, the expense of these recombinant agents is the reason why the more traditional plasma Isolates are used—despite the possibility of viral transmission. 

HIV has affected more than 40 million people in last three decades. Multiple steps in HlV-1 cycle have been reported to be interfered by flavraies and their derivatives (Fig. 8). Early reports have described inhibitirHi of HIV-1 transcription by 5,7-dihydroxyflavone chrisin that stops casein kinase-II activity [99]. More recently, it has been reported that scutellarin inhibits viral transmission on HlV-1 strains affecting its reverse transcriptase activity, particle attachment, and ceU fusion [100]. Antitrypanosomal and antileishmanial activities without cytotoxicity in vitro and in vivo have been reported for 7,8-dihydroxyflavone and quercetin [101]. 

From an implant safety perspective, one of the areas that generates the most attention with xenografts is the potential for viral transmission. There are viruses present in some species which, if transmitted to humans, could have very serious consequences. Of particular concern are endogenous retroviruses which are present in all mammals... 

In 46 patients with primary immunodeficiency treated with intravenous immunoglobulin 10%, no subject converted for hepatitis A, B or C, HIV, or parvovirus B19 [44 ]. In a subgroup of the 1MPACT2 trial, none of the 16 patients treated with plasma-derived Cl -inhibitor concentrate seroconverted for HIV, hepatitis viruses, or parvovirus B19. This report adds to the almost 40 years of experience with treatment of attacks of hereditary angioedema with plasma-derived Cl -INH, in which no detectable viral transmission occurred [26 j. Probable clinically asymptomatic parvovirus B19 seroconversion was reported in 3 of 20 patients after administration of prothrombin complex concentrate [32 ]. Hepatitis-associated aplastic anemia may be... 

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