Please Scroll Down to See Forums Below
napsgear
genezapharmateuticals
domestic-supply
puritysourcelabs
UGL OZ
UGFREAK
napsgeargenezapharmateuticals domestic-supplypuritysourcelabsUGL OZUGFREAK

How one can die from too much water (for those who would like to know)

  • Thread starter Thread starter heatherrae
  • Start date Start date
H

heatherrae

Guest
http://en.wikipedia.org/wiki/Water_intoxication

Water intoxication
From Wikipedia, the free encyclopedia

Water intoxication (also known as hyperhydration or water poisoning) is a potentially fatal disturbance in brain function that results when the normal balance of electrolytes in the body is pushed outside of safe limits by a very rapid intake of water.[1]

Physiology of water intoxication
Body fluids contain electrolytes (particularly sodium compounds, such as sodium chloride) in concentrations that must be held within very narrow limits. Water enters the body orally or intravenously and leaves the body primarily in the urine, sweat and by exhaled water vapour. If water enters the body more quickly than it can be removed, body fluids are diluted and a potentially dangerous shift in electrolyte balance occurs.

Most water intoxication is caused by hyponatremia, an overdilution of sodium in the blood plasma, which in turn causes an osmotic shift of water from extracellular fluid (outside of cells) to intracellular fluid (within cells). The cells swell as a result of changes in osmotic pressure and may cease to function. When this occurs in the cells of the central nervous system and brain, water intoxication is the result. Additionally, many other cells in the body may undergo cytolysis, wherein cell membranes that are unable to stand abnormal osmotic pressures rupture, killing the cells. Initial symptoms typically include light-headedness, sometimes accompanied by nausea, vomiting, headache and/or malaise. Plasma sodium levels below 100 mmol/L (2.3g/L) frequently result in cerebral edema, seizures, coma, and death within a few hours of drinking the excess water. As with alcohol poisoning, the progression from mild to severe symptoms may occur rapidly as the water continues to enter the body from the intestines or intravenously.

A person with two healthy kidneys can excrete about 900ml (0.24 gal)/hr[2]. Consuming as little as 1.8 litres of water (0.48 gal) in a single sitting may prove fatal for a person adhering to a low-sodium diet, or 3 litres (0.79 gallons) for a person on a normal diet. However, this must be modulated by potential water losses via other routes. For example, a person who is perspiring heavily may lose 1 L/hr (0.26 gal) of water through perspiration alone, thereby raising the threshold for water intoxication. The problem is further complicated by the amount of electrolytes lost in urine or sweat, which is variable within a range controlled by the body's regulatory mechanisms. Water intoxication can be prevented by consuming water that is isotonic with water losses, but the exact concentration of electrolytes required is difficult to determine and fluctuates over time, and the greater the time period involved, the smaller the disparity that may suffice to produce electrolyte imbalance and water intoxication.

Sodium is not the only mineral that can become overdiluted from excessive water intake. Magnesium is also excreted in urine. According to the National Institutes of Health, "magnesium deficiency can cause metabolic changes that may contribute to heart attacks and strokes."[3] Intravenous magnesium is used in cardiac care units for cardiac arrhythmias.[4]


[edit] Persons at high risk of water intoxication

[edit] Infants
It can be very easy for children under a year old to absorb too much water – especially if the child is under nine months old. [5]


[edit] Runners
Marathon runners are susceptible to water intoxication if they drink only water while running. Although sweat is relatively hypotonic compared with body fluids, marathon runners perspire heavily for long periods, potentially causing their sodium levels to drop when they consume large amounts of fluids to quench their thirst. The replacement fluids may not contain sufficient sodium to replace what has been lost, and this puts them at high risk for water intoxication. Medical personnel at marathon events are trained to immediately suspect water intoxication when runners collapse or show signs of confusion. Properly designed electrolyte-replacement drinks and some sports drinks include electrolytes that make them roughly isotonic with sweat, which helps to prevent water intoxication.

Note that overconsumption of sodium (in drinks or also in food), as well as inadequate intake of water, can cause hypernatremia, a disorder that is nearly the opposite of water intoxication and equally dangerous. Improper use of salt tablets can cause hypernatremia also.


[edit] Overexertion and heat stress
Any activity or situation that promotes heavy sweating can lead to water intoxication when water is consumed to replace lost fluids. Persons working in extreme heat and/or humidity for long periods must take care to drink and eat in ways that help to maintain electrolyte balance. Persons using drugs such as MDMA may overexert themselves, perspire heavily, and then drink large amounts of water to rehydrate, leading to electrolyte imbalance and water intoxication. Even persons who are resting quietly in extreme heat or humidity may run the risk of water intoxication if they drink large amounts of water over short periods for rehydration.


[edit] Psychiatric conditions
Psychogenic polydipsia is the psychiatric condition in which patients feel compelled to drink large quantities of water, thus putting them at risk for water intoxication. This condition can be especially dangerous if the patient also exhibits other psychiatric indications (as is often the case), as his or her care-takers might misinterpret the hyponatraemic symptoms.


[edit] Unusual water losses in disease
Diarrhea and vomiting can result in very large electrolyte losses, and although drinking water will replace lost water, the lost electrolytes may not be adequately replaced, which can result in water intoxication. Replacement fluids for vomiting and diarrhea should be properly balanced to make them isotonic with the fluids lost in these conditions. Special formulations exist for oral rehydration therapy in these cases.

A great many disorders can affect electrolyte balance, especially disorders of the kidneys. Diuretic therapy, mineralocorticoid deficiency, osmotic diuresis (as in the hyperglycemia of uncontrolled diabetes), and the multiple disorders associated with AIDS are other common causes of electrolyte imbalance, although they do not always produce water intoxication.


[edit] Iatrogenic water intoxication
When an unconscious person is being fed intravenously (for example, total parenteral nutrition (TPN)) or via a nasogastric tube), the fluids given must be carefully balanced in composition to match fluids and electrolytes lost. If the fluids administered are hypotonic with respect to fluids lost, electrolyte imbalance and water intoxication may result. The latter may not be immediately obvious in an unconscious patient. The electrolyte status of patients on TPN must be monitored carefully even when they are ambulatory.


[edit] Drug users
Sometimes users of marijuana or other substances will consume large quantities of water in order to receive a negative urinalysis test for that substance.

Water Intoxication has also been linked to over-consumption of water due to the effects of MDMA. Although many cases of this clearly involved individuals drinking large amounts of water, there are cases where there is no evidence of excessive water consumption. Their cases may be caused by MDMA inducing release of the antiduretic hormone vasopressin by the pituitary gland. This causes one to retain water to a greater extent. The death of British teen Leah Betts may be the most widely publicised MDMA-related fatality, and resulted from her consuming too much water due to concerns over dehydration. Signs of hyponatremia include confusion, nausea, headache and loss of consciousness. Hyponatremia in MDMA users is a medical emergency and requires prompt treatment. In general, females are at greater risk of developing symptoms and dying from hyponatremia than males.


[edit] Treatment
Mild intoxication may remain asymptomatic and require only fluid restriction. In more severe cases, treatment consists of:

Diuretics to increase urination, which are most effective for excess blood volume
Saline given intravenously to restore sodium electrolyte levels
Vasopressin receptor antagonists

[edit] Prevention of water intoxication
Water intoxication can be prevented if a person's intake of water and electrolytes closely matches his or her losses. The body's regulatory mechanisms provide a very generous margin of safety if the two are imbalanced, but some extreme activities (such as heavy, prolonged physical exertion), as well as disease states, can overwhelm or impair these mechanisms. Avoid situations that provoke extreme or prolonged perspiration. Drinking fluids that are specially balanced to replace lost electrolytes can also help to prevent intoxication. Eating regularly can provide needed electrolytes if only normal water is available for rehydration.

Sports drinks are popular among athletes because they provide the necessary electrolytes to support extended exercise. They help keep the body balanced and carrying the right amount of fluids. However, not all drinks advertised as sports drinks are suitable for this purpose, and professional advice should be sought for potentially risky situations such as those described above.

Note that a person's innate sense of thirst is more sensitive to overall dehydration than to changes in electrolytes. Thus, it is possible to develop water intoxication while trying to satisfy thirst, if one drinks a great deal of water over a short period. A dangerous drop in electrolytes, such as the hyponatremia that leads to water intoxication, will not have any effect on thirst if one is sufficiently dehydrated.

For people suffering from dehydration due to the heavy perspiration associated with heavy exertion or heat stress, drinking water to rehydrate is much more important than avoiding water intoxication, since the former is extremely common and the latter is rare. One should never avoid drinking water under such conditions; instead, other steps should be taken to ensure that electrolytes are replaced as well, as noted above.


[edit] Notorious cases of water intoxication
In a much-publicized case of fraternity hazing, four members of the Chi Tau (Formally Delta Sigma Phi) House at California State University, Chico pled guilty to forcing 21-year-old student Matthew Carrington to drink excessive amounts of water while performing calisthenics in a frigid basement as part of initiation rites on February 2, 2005.[6] He collapsed and died of heart failure due to water intoxication.
New Zealand race-walker Craig Barrett collapsed during the last kilometer of the 50 km walk in the 1998 Commonwealth Games in a non-fatal case of water intoxication.
On January 12, 2007, Jennifer Strange, a 28-year-old woman from Rancho Cordova, California, was found dead in her home by her mother hours after trying to win a game console in KDND 107.9 "The End" radio station's "Hold Your Wee for a Wii" contest, which involved drinking large quantities of water without urinating. Every 15 minutes contestants were given a bottle of water to drink. It was reported that original amounts were very small (250 mL, 8 fl. oz.) and the bottle size increased as contestants progressed. On January 15 the radio station suspended the show, and the following day John Geary, vice president and general manager of KDND's parent company, Entercom/Sacramento, fired the three hosts of KDND-FM's "Morning Rave" (Trish, Maney, and Lukas) and seven other employees, two of which were the On-Air personalities "Carter" and "Fester". The "Morning Rave" had been on the air for about five years and was one of the capital's top-ranked morning drive programs. In all, according to witness reports, Strange may have drunk nearly two gallons. Afterward, she appeared ill when she went on the air, one contestant said. Following the contest, Strange called in sick to work. About five hours later she was found dead at her home. In the studio, Ybarra said Strange showed fellow contestants photographs of her two sons and daughter, for whom she was hoping to win the Wii. The game console retails for about $250 but, at the time of the competition, it was sold-out throughout North America and was almost impossible to find yet very sought-after.[7][8] Gina Sherrod, who competed with Strange in the contest, said her family listened to the radio show, and told her that a nurse was on air warning that drinking too much water is dangerous. Sherrod said a DJ rebuffed the nurse, saying the contestants signed waivers, however it was later reported these waivers addressed only publicity issues and did not mention health or safety concerns. Sherrod said she had no idea what risk she had taken until she saw news of Strange's death.[9][10][11][12][13]
Other notable fatalities due to water intoxication include Leah Betts,[14] Anna Wood, [15] 2002 Boston Marathon competitor Cynthia Lucero,[16] and Washington, D.C. police officer James McBride.[17]
 
borrring, thread about this yesturday
 
HIV infection resulting from blood transfusion has been documented repeatedly since the first case report in late 1982.(6-8,9) In the United States, almost all cases are due to blood transfused before March 1985, when HIV antibody testing became available to screen donated blood. As of December 2001, an estimated 14,262 persons have been diagnosed with AIDS as a result of transfusing contaminated blood or blood products.(10)

In some resource-rich countries, testing of donated blood for HIV antibodies was not immediately initiated for a variety of reasons. France began HIV antibody testing in June 1985, Canada began testing in November 1985, and Switzerland began testing in May 1986. Germany inconsistently tested plasma products between 1987 and 1993, as did Japan in 1985 and 1986. These delays led to criminal investigations in France, Germany, Switzerland, and Japan, which in some cases led to criminal conviction of those persons found to be responsible.(11) At least 20 countries initiated compensation programs for at least some individuals infected by transfusion of HIV-contaminated blood and blood products.(11,12)

The risk of HIV transfusion through infected blood products exceeds that of any other risk exposure. Ninety percent of recipients transfused with HIV antibody-positive blood are found to be HIV infected at follow-up.(1) No HIV-infected but persistently seronegative transfusion recipients have been identified. The 90% probability of seroconversion is independent of the age or sex of the recipient, the reason for transfusion, and the type of component transfused (excluding washed red blood cells, which transmit HIV at a lower rate).(13)

HIV infectivity of red blood cell components that were not washed before transfusion decreases as storage time increases. HIV-contaminated red blood cells stored for <8 days are 96% infectious, whereas those stored for >3 weeks are 50% infectious.(1) The level of a donor's viremia at the time of donation is also an important determinant of HIV transmission risk, but no other donor characteristics have been found to affect transmission.(14) Of all transfused patients, half die within 6 months after transfusion from the underlying disease that necessitated the transfusion. Currently, cases involving transfusion of HIV-positive blood do not increase the overall 1-year posttransfusion mortality rate of recipients in the United States. In Zaire, however, patients transfused with HIV-positive blood are 31% more likely to be dead 1 year after transfusion than are patients transfused with HIV-negative blood.(15) This difference is unexplained but emphasizes the importance of screening blood for HIV in developing countries.

HIV disease due to transfusion progresses in the recipient at rates comparable to those in individuals infected for similar duration but by other routes.(16,17) One report found that a transfusion recipient may develop AIDS more rapidly if the infected blood component comes from a blood donor who develops AIDS soon after the time of the blood donation.(18) Other analyses, however, do not confirm this finding.(19) It is more likely that host factors, particularly the recipient's age and immune status, and perhaps other as-yet-undefined cofactors influence the progression to AIDS.(20,21) The mean time of progression to AIDS is estimated to be 8.2 years for adult transfusion recipients who receive no antiretroviral therapy, with a cumulative prevalence of 20% having AIDS 5 years after infection.(22) This progression rate may be overestimated, and the mean time to AIDS development underestimated, because these values are based primarily on data from recipients identified because they developed AIDS or because they received blood from donors who subsequently developed AIDS. The data exclude many donors and recipients who have not been identified because they remain asymptomatic.

Single Donor Components Since 1985

Transmission of HIV by transfusion has become rare in developed countries since the initiation of voluntary deferral of donors at risk for HIV infection and routine HIV antibody testing of all donations. Continued improvement in donor recruitment practices, donor education, donor screening, and blood testing has resulted in continued decreases in the risk of transfusion transmission of HIV. In 1995, the risk in the United States of HIV-1 transmission per unit transfused was estimated to be between 1 in 450,000 and 1 in 660,000.(23,24) By 2003, this estimated risk had decreased to between 1 in 1.4 million and 1 in 1.8 million units.(25,26)

HIV antibody tests fail to identify HIV-infected blood donated by HIV-infected persons who have not yet seroconverted. Exclusion of donors is voluntary. Interviews with HIV antibody-positive donors reveal that most recognize their risk but fail to exclude themselves.(27) As a result, laboratory efforts to eliminate HIV-infected donors have continued and testing has improved. Currently, HIV antibody tests detect both HIV-1 and HIV-2 and detect antibody approximately 22 days (the "window period") after the viremic phase of HIV infection begins. Antigen testing for p24, mandated by the U.S. Food and Drug Administration (FDA) in 1996, shortened the window period to approximately 16 days. The nucleic acid amplification test (NAT), which detects HIV-1 RNA in minipools (16-24 donation samples/pool), was introduced in the United States in 1999 and further reduces the window period of potential HIV transmission to 11 days.(25,26) As of early 2003, three transfusion recipients are known to have become HIV infected by transfusion of HIV antibody-negative, p24 antigen-negative, and HIV NAT-negative blood from two different blood donors (among 25 million donations).(28)

The global perspective is not so bright as that described for resource-rich countries. Worldwide, 75 million units of blood are estimated to be donated annually, compared with 13 million donations in the United States. Of the 191 WHO member states, only 43% test blood for HIV, hepatitis C, and hepatitis B viruses. Transfusion-transmitted HIV infection is thought to account for 80,000-160,000 infections annually, contributing 2-4% of all cases of HIV transmission.(25,29,30) Only 20% of the world's supply of safe blood is available to countries with 80% of the world's population.

Inadequate funding for HIV testing is only part of the problem. Specific issues that urgently need to be addressed include the lack of a sufficient volunteer blood donor pool, and inadequate blood donor screening, information, counseling, and confidentiality. Implementation of standardized and monitored test manufacturing practices, inclusion of test validation procedures, ongoing staff training, and continuous internal and external quality assessment programs are all necessary components of an effective program to prevent transmission. Moreover, transfusion practices must be monitored locally so that HIV transmission from unnecessary transfusions does not occur.

HIV-2

No transfusion-associated HIV-2 cases have been reported in the United States. HIV-2 infection is endemic to western Africa and rarely is reported in the United States, with 24 of the 62 reported cases identified in the northeastern United States.(31) Occasional cases have occurred in Europe.(32,33) Forty-eight of the 62 persons in the United States known to be infected with HIV-2 were born in, had traveled to, or had a sex partner from western Africa. Since June 1, 1992, United States blood banks screen donations for HIV-2. HIV-1 antibody ELISA tests detect 8-92% of HIV-2 infections, depending on the geographic source of sera and the test used. As of 1998, screening has identified four blood or plasma donors with HIV-2 infection.(31,34)

Idiopathic CD4 Lymphocytopenia

The term idiopathic CD4 T lymphocytopenia (ICL) describes the condition of patients who develop HIV-associated diseases and have CD4 lymphocyte counts of <300 cells/µL, but are not HIV infected. To date, follow-up studies of blood donors and transfusion recipients with ICL provide no evidence that ICL is caused by a blood-borne agent.(35-37) ICL appears to be caused by a heterogeneous number of immunosuppressive conditions rather than by a single virus.


HIV Transmission from Plasma-Derived Blood Products

To produce plasma-derived products, plasma from 2,000 to 30,000 donors is pooled and processed into a single batch (lot). One HIV-infected donor can contaminate an entire lot of product and consequently infect each of the recipients if HIV is not neutralized by sufficient heat, cold ethanol, or other treatments during production. A variety of different blood products can be manufactured by successive precipitation with increasing concentrations of cold ethanol. Individual fractions are then further processed, during which time partially concentrated fractions from as many as 100,000 donors may be combined.(38)
Albumin and Immune Globulin Products

Albumin and plasma protein (Cohn fractions IV and V) are extracted with the maximum concentration of cold ethanol and are then pasteurized. They do not transmit HIV. Cohn fraction II products (ie, immune globulins such as Rh immune globulin, gamma globulin, and hepatitis B immune globulin) are treated with somewhat lower concentrations of cold ethanol and cannot be pasteurized without loss of activity. Nevertheless, HIV has not been cultured from lots of Cohn fraction II products known to be positive for HIV antibody. The presence of high-titer antibody to HIV in some lots of hepatitis B immune globulin has resulted in transient (<6 months' duration), low-titer antibody to HIV in recipients and has raised questions about the safety of these products. There have been, however, no documented cases of HIV disease as a result of their use. Over 4.5 million doses of Rh immune globulin have been given since 1968, with no reported cases of HIV disease in recipients. Thus, although recipients of hepatitis B immunoglobulin may become transiently HIV antibody positive by passive acquisition of antibodies from the immunoglobulin preparation, there is no evidence that these individuals are actually infected.(39,40)

Clotting Factor Concentrates

Pooled plasma is also precipitated and processed into the factor VIII concentrates used to treat hemophilia A and into factor IX concentrates used to treat hemophilia B. Before 1984, factor concentrates were not heat treated, because heat treatment causes a loss of hemostatic activity. As a result, HIV was not inactivated, and roughly 80% of treated hemophilia A patients and 50% of treated hemophilia B patients were infected with HIV-1.(41-43) The severity of hemophilia, and thus the amount of factor concentrate received, correlated directly with the probability of becoming HIV seropositive. Lower rates of seroprevalence in hemophilia B patients compared to hemophilia A patients appear to be related to the use of higher concentrations of ethanol in the manufacture of factor IX concentrate.

Since 1984, multiple methods for inactivating HIV have been developed and applied.(44,38) Methods vary, but all use both heat treatment and at least one other viral inactivation process. No HIV antibody seroconversions have yet occurred among uninfected persons using factor products now on the market. Improved safety and purity of plasma-derived concentrates does, however, result in a sixfold increase in the annual cost of clotting factor replacement.(45)

Cloning of the factor VIII gene in the late 1980s allowed for the development of recombinant factor products, and preparations purified by monoclonal antibody affinity techniques are now available. Some hemophilia clinicians use these "ultrapure" and "high-purity" products for factor replacement in HIV-infected hemophiliacs because this method decreases exposure to foreign antigen, which evidence suggests may hasten progression of HIV disease.(46-48)


Hemophilia and Progression to AIDS

The rate of progression to AIDS in HIV-positive hemophiliacs is directly related to age at the time of HIV infection. The incidence of AIDS in older adult hemophiliacs infected with HIV is comparable to that of HIV-infected homosexual men and transfusion recipients in the same age group.(49,50) Over an 8-year period, older HIV-infected hemophiliacs are more likely than younger HIV-infected hemophiliacs to develop AIDS (13.3% for ages 1-17 years, 26.8% for ages 19-34 years, and 43.7% for ages 35-70 years).(50) Severity of hemophilia and amount of factor concentrate received have not been shown to influence the rate of progression to AIDS in HIV-infected hemophiliacs.(51)

Lack of Blood Product-Associated Kaposi Sarcoma or Lymphoma

There is a striking and unexplained absence of lymphoma and Kaposi sarcoma (KS) in hemophiliacs with advanced HIV disease, two thirds of whom present with Pneumocystis jiroveci pneumonia. The next most common presenting diagnoses are esophageal candidiasis (9%) and extrapulmonary cryptococcosis (6%).(52) The absence of KS suggests that human herpesvirus 8 (HHV-8), a gamma herpesvirus detected in 100% of KS lesions, is not readily transmitted by blood products.

HIV Transmission in Transplant Recipients

HIV has been transmitted through transplantation of kidney, liver, heart, pancreas, bone, and skin--all of which are blood-containing organs or highly vascular tissues. There are no reports of HIV tissue transmission from HIV-seropositive donors of cornea, ethanol-treated and lyophilized bone, fresh-frozen bone without marrow, lyophilized tendon or fascia, or lyophilized and irradiated dura mater.(53)

Although more than 100,000 organ transplants and 1 million tissue allografts have been performed since 1980, one review described only 32 reports of 75 cases of HIV transmission.(53) The majority of cases occurred before the availability of HIV antibody testing in 1985. Of the 11 reported recipients infected with HIV via transplant after 1985, one received an urgent liver transplant before HIV test results from the donor were available,(54) and one received a kidney from a donor who had been HIV tested 8 months before and then had subsequently seroconverted.(55) Two recipients received an organ from a donor whose plasma had been diluted by emergency transfusion before HIV testing.(56) Notably, however, one HIV-seronegative donor without known risk factors for HIV donated tissues and organs to 48 recipients, of whom 41 were tested for HIV and seven were found to be infected.(57) Four of the seven infected recipients received organ transplants, and three received unprocessed fresh-frozen bone. Of the 34 HIV-tested, seronegative recipients, 25 received ethanol-treated bone, corneas, soft tissue (including fascia lata, tendons, ligaments, arteries, veins), or dura mater.

The low incidence of transplant-related HIV infection is due to adequate donor screening procedures, sensitive and accurate HIV testing, and, when possible, virucidal processing techniques. As with blood transfusion, tissue from the recently HIV-infected donor who has not yet seroconverted must be specifically targeted for exclusion. This process is a greater challenge in the setting of cadaveric transplants, where donor selection cannot incorporate the direct questioning and confidential exclusion techniques used for blood collection.

HIV Transmission by Artificial Insemination


Unprocessed Donor Semen

Currently, 15 women are known to have been infected with HIV via artificial insemination using sperm from anonymous donors: one in Germany,(58) two in Italy,(59) four in Australia,(60) two in Canada,(61) and six in the United States.(61,62) All but one of these cases of insemination-related infection occurred before the availability of HIV antibody testing. Another woman was infected after insemination with processed sperm from her HIV-seropositive hemophiliac husband.(63) These reports demonstrate that HIV transmission can occur after the use of fresh, cryopreserved, or processed sperm. Both intrauterine insemination and cervical insemination can result in HIV transmission. Other generalizations about the risk of HIV transmission via this route are limited by the retrospective nature of the follow-up, the limited number of infected recipients, and the lack of information regarding HIV viral load of the seropositive donors or other host factors in either donor or recipient at the time of insemination. However, given that approximately 75,000 women are artificially inseminated annually in the United States, it can be concluded that HIV transmission from unrelated semen donors was an infrequent event prior to the availability of HIV testing.(64)

Donor Screening

Current guidelines of the U.S. Centers for Disease Control and Prevention (CDC) recommend screening semen donors for HIV antibody on the day of semen donation, freezing the semen, and not using it until the donor is tested again 6 months later and found to be HIV antibody negative.(65) Comparisons of fresh versus frozen sperm show that frozen sperm is 50% less efficacious in fertilization because of decreased sperm motility and viability. The increased number of inseminations required to offset the use of frozen sperm are thought to cost millions of dollars a year in the United States. Proponents for less restrictive recommendations that would not require freezing of sperm argue that an updated review of the risks, benefits, and costs of donor insemination indicate that the risk of HIV infection would be similar to that of blood transfusion (see above).(66) Advances in donor screening, education, and testing are such that the number of newly HIV-infected semen donors within the "window period" prior to the development of detectable antibody is small. Use of HIV NAT tests of donor serum may further limit the number of HIV-transmitting donors.

Processed Semen from HIV-Positive Males

The CDC recommends against insemination from HIV-positive men, but some HIV-discordant couples are highly motivated to conceive genetically related children and have used processed semen to reduce the risk of HIV transmission. In a case report from the United States, processing fresh ejaculate by centrifugation to remove cells failed to prevent HIV transmission to women following artificial insemination.(63) A modification of this technique in Italy, however, appears successful in preventing transmission; 29 women were inseminated, and none seroconverted.(67) All 10 babies born to these women have remained HIV negative. The processing method involved centrifugation, repeated washing, and an incubation period that allowed spermatozoa to swim up to the upper layer of the culture medium. Several centers in Europe have now successfully inseminated several hundred HIV-negative women by HIV-positive partners without HIV transmission using this type of protocol.(68) Although this procedure involves some risk of HIV transmission, it may offer reduced risk for highly motivated HIV-discordant couples seeking artificial insemination. These results also provide evidence against the controversial claim that HIV is transmitted by spermatozoa as opposed to infected leukocytes and free virus in seminal fluid.(69,70)



References
 
Mavafanculo said:
lol yosemite sam to buggs bunny ?? or was it that little gangster guy
ROFL...the little gangster. I can't believe you knew that one. LOL. I say it all the time, but it actually went "Shaddup shudinup, rabbit."
 
Top Bottom