Suspected Mexico flu toll hits 81 BBC Reported

According to BBC News Website

"The Mexican authorities say 81 people are now thought to have been killed by an outbreak of a human swine flu virus."

People have been told to stay at home to contain the infection, which the World Health Organization (WHO) has warned could become a pandemic.

Confirmed or suspected cases have also been reported in the US and elsewhere.

At least some confirmed cases show a new version of the H1N1 swine flu sub-strain - a disease which infects pigs but only sporadically infects humans.

SWINE FLU Swine flu is a respiratory disease found in pigs Human cases usually occur in those who have contact with pigs Human-to-human transmission is rare and such cases are closely monitored

H1N1 is the same strain that causes seasonal flu outbreaks in humans, but the newly detected version contains genetic material from versions which usually affect pigs and birds.

There is currently no vaccine for the new strain but severe cases can be treated with antiviral medication.

It is unclear how effective currently available flu vaccines would be at offering protection against the new strain, as it is genetically distinct from other flu strains.

The respiratory virus is spread mainly through coughs and sneezes.

Although all of the deaths so far have been in Mexico, the flu is spreading in the United States and suspected cases have been detected elsewhere:

• Eleven confirmed infections in the US
• In addition, eight suspected cases are being investigated at a New York City high school where about 200 students fell mildly ill with flu-like symptoms
• Twenty-two students and three teachers in New Zealand, some suffering flu-like symptoms, have been quarantined and tested for swine flu after returning from a trip to Mexico
• But a UK hospital conducting tests for swine flu on a British Airways cabin crew member admitted on Saturday said the tests proved negative.

Read Full Store at: http://news.bbc.co.uk/2/hi/americas/8018991.stm

Zanamivir

zanamivir relenza zanamivir

Zanamivir is a drug for the treatment of flu (influenza), developed by GlaxoSmithKline and marketed as Relenza. It is taken as an inhalation of powder into the lungs, and reduces the severity and duration of flu symptoms.

The treatment is for use by people over the age of seven, who have Influenza A or Influenza B, and who have not had the symptoms for more than two days.

It is impossible to be absolutely sure someone has influenza without doing laboratory tests, but these take too long for them to be of any practical value. Therefore, the way in which it is suggested zanamivir is used, is that it be given to people who develop "symptoms of 'flu" when influenza is known to be circulating.

Unfortunately zanamivir has the drawback that it can cause tightness of the tubes in the lungs (bronchospasm) in some patients, and it is not recommended for people with airways disease, eg asthma or chronic obstructive pulmonary disease (COPD). This therefore excludes quite a high percentage of people that might otherwise have benefited from its use.

Oseltamivir

Oseltamivir

Oseltamivir Phosphate

Oseltamivir is a potent and selective inhibitor of the neuraminidase enzyme of the influenza viruses A and B. The neuraminidase enzyme is responsible for cleaving sialic acid residues on newly formed virions and plays an essential role in the release and spread of progeny virions. When exposed to oseltamivir, the influenza virions aggregate on the surface of the host cell, thereby limiting the extent of infection within the mucosal secretions (McNicholl 2001) and reducing viral infectivity.

Oseltamivir is indicated in the prophylaxis of influenza and for the treatment of uncomplicated acute illness due to influenza in patients 1 year and older who have been symptomatic for no more than 2 days. H5N1 strains are generally sensitive against oseltamivir, but there are no data on its clinical efficacy.

Clinical studies have shown that neuraminidase inhibitors can decrease the duration of influenza-related symptoms if initiated within 48 hours of onset. Clinical efficacy is about 60-70 % and, for treatment started within 48 hours, symptoms such as myalgias, fever, and headache were reduced by approximately 0.7-1.5 days (McNicholl 2001). Treatment is more effective if initiated within 30 hours of symptom onset in febrile individuals. Treatment with oseltamivir does not seem to adversely affect the primary in vivo cellular immune responses to influenza virus infection (Burger 2000).

Oseltamivir is generally well-tolerated with the only clinically important side effect being mild gastrointestinal upset (Doucette 2001). Recently, the drug has been linked to a number of cases of psychological disorders and two teenage suicides in Japan. However, there is currently no evidence of a causal relationship between oseltamivir intake and suicide.

Rimantadine

Rimantadine

Rimantadine is an M2 ion channel inhibitor which specifically inhibits the replication of influenza A viruses by interfering with the uncoating process of the virus. M2 inhibitors block the ion channel formed by the M2 protein that spans the viral membrane (Hay 1985, Sugrue 1991). The influenza virus enters its host cell by receptor-mediated endocytosis. Thereafter, acidification of the endocytotic vesicles is required for the dissociation of the M1 protein from the ribonucleoprotein complexes. Only then are the ribonucleoprotein particles imported into the nucleus via the nuclear pores. The hydrogen ions needed for acidification pass through the M2 channel. Rimantadine blocks the channel (Bui 1996).

The drug is effective against all influenza A subtypes that have previously caused disease in humans (H1N1, H2N2 and H3N2), but not against influenza B virus, because the M2 protein is unique to influenza A viruses. Rimantadine is not active against the avian flu subtype H5N1 strains that have recently caused disease in humans (Li 2004).

For both the prevention and treatment of influenza A, rimantadine has a comparable efficacy to amantadine but a lower potential for causing adverse effects (Stephenson 2001, Jefferson 2004).

The development of neutralising antibodies to influenza strains seems not to be affected by rimantadine. However, the presence of IgA in nasal secretions was significantly diminished in one study (Clover 1991).

A recently published study revealed an alarming increase in the incidence of amantadine-resistant and rimantadine-resistant H3N2 influenza A viruses over the past decade. In a recently published study, which assessed more than 7,000 influenza A viruses obtained worldwide from 1994 to 2005, drug resistance against amantadine and rimantadine increased from 0.4 % to 12.3 % (Bright 2005). Viruses collected in 2004 from South Korea, Taiwan, Hong Kong, and China show drug-resistance frequencies of 15 %, 23 %, 70 %, and 74 %, respectively. Some authors have suggested that the use of amantadine and rimantadine should be discouraged (Jefferson 2006). Recently, 109 out of 120 (91 %) of influenza A H3N2 viruses isolated from patients in the US contained an amino acid change at position 31 of the M2 protein, which confers resistance to amantadine and rimantadine. On the basis of these results, the Centre for Disease Control recommended that neither amantadine nor rimantadine be used for the treatment or prophylaxis of influenza A in the United States for the remainder of the 2005-06 influenza season (CDC 2006).

Rimantadine is an M2 ion channel inhibitor which specifically inhibits the replication of influenza A viruses by interfering with the uncoating process of the virus. M2 inhibitors block the ion channel formed by the M2 protein that spans the viral membrane (Hay 1985, Sugrue 1991). The influenza virus enters its host cell by receptor-mediated endocytosis. Thereafter, acidification of the endocytotic vesicles is required for the dissociation of the M1 protein from the ribonucleoprotein complexes. Only then are the ribonucleoprotein particles imported into the nucleus via the nuclear pores. The hydrogen ions needed for acidification pass through the M2 channel. Rimantadine blocks the channel (Bui 1996).

The drug is effective against all influenza A subtypes that have previously caused disease in humans (H1N1, H2N2 and H3N2), but not against influenza B virus, because the M2 protein is unique to influenza A viruses. Rimantadine is not active against the avian flu subtype H5N1 strains that have recently caused disease in humans (Li 2004).

For both the prevention and treatment of influenza A, rimantadine has a comparable efficacy to amantadine but a lower potential for causing adverse effects (Stephenson 2001, Jefferson 2004).

The development of neutralising antibodies to influenza strains seems not to be affected by rimantadine. However, the presence of IgA in nasal secretions was significantly diminished in one study (Clover 1991).

A recently published study revealed an alarming increase in the incidence of amantadine-resistant and rimantadine-resistant H3N2 influenza A viruses over the past decade. In a recently published study, which assessed more than 7,000 influenza A viruses obtained worldwide from 1994 to 2005, drug resistance against amantadine and rimantadine increased from 0.4 % to 12.3 % (Bright 2005). Viruses collected in 2004 from South Korea, Taiwan, Hong Kong, and China show drug-resistance frequencies of 15 %, 23 %, 70 %, and 74 %, respectively. Some authors have suggested that the use of amantadine and rimantadine should be discouraged (Jefferson 2006). Recently, 109 out of 120 (91 %) of influenza A H3N2 viruses isolated from patients in the US contained an amino acid change at position 31 of the M2 protein, which confers resistance to amantadine and rimantadine. On the basis of these results, the Centre for Disease Control recommended that neither amantadine nor rimantadine be used for the treatment or prophylaxis of influenza A in the United States for the remainder of the 2005-06 influenza season (CDC 2006).

Swin Flue Vaccine will Be Prepared In China

People Republic of China (PRC) on Sunday rushed the first batch of swine flu vaccine to the southwestern province of Sichuan, where an outbreak of the disease has killed 34 people and left 28 in critical condition.

Vaccines for 350,000 pigs were flown to Chengdu, the capital of Sichuan, where the infection has swept through about 100 villages, Xinhua news agency reported.

It said vaccines for a total of 10 million pigs were being produced to combat the disease, which is contracted from slaughtering, handling or eating infected pigs.

Pork is People Republic of China (PRC)’s favourite meat and the country consumes more of it than anywhere else in the world. Of 618 million pigs slaughtered in 2004, Sichuan accounted for about 14 percent. About 50,000 health workers and officials have been sent to the province to inspect every pig and to educate poor farmers not to slaughter sick pigs or eat their meat.

A Health Ministry statement on Saturday said Sichuan had notified 174 confirmed or suspected cases of Streptococcus suis bacteria, or swine flu.

The outbreak has forced Sichuan to suspend all exports of chilled and frozen pork from Ziyang city and surrounding Neijiang prefecture to Hong Kong, which said on Sunday that another resident had contracted the disease.

Drug Amantadine

Amantadine is used to treat Parkinson's disease and conditions similar to those of Parkinson's disease. It also is used to prevent and treat respiratory infections caused by influenza A virus.

Before taking amantadine,

• tell your doctor and pharmacist if you are allergic to amantadine or any other drugs.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially benztropine (Cogentin), hydrochlorothiazide with triamterene (Maxzide, Dyazide), medication for depression, other medication for Parkinson's disease, medication for spasms of the stomach or intestines, stimulants, trihexyphenidyl (Artane), and vitamins.
• tell your doctor if you have epilepsy or any other type of seizures, or have ever had heart, kidney, or liver disease, heart failure, low blood pressure, recurring skin rash, or mental illness.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking amantadine, call your doctor immediately. Amantadine may cause harm to the fetus.
• this medicine may cause blurred vision; be careful when driving or doing things requiring alertness.

Side Effects

Amantadine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• blurred vision
• dizziness
• lightheadedness
• faintness
• trouble sleeping

If you experience any of the following side effects, call your doctor immediately:

• depression or anxiety
• swelling of the hands, legs, or feet
• difficulty urinating
• shortness of breath
• rash

Swine Flu Shots

There are four different antiviral drugs that are licensed for use in the US for the treatment of influenza:

amantadine
rimantadine
oseltamivir
zanamivir

While most swine influenza viruses have been susceptible to all four drugs, the most recent swine influenza viruses isolated from humans are resistant to amantadine and rimantadine. At this time, CDC recommends the use of oseltamivir or zanamivir for the treatment and/or prevention of infection with swine influenza viruses.