Tips for containing spread of swine flu

A swine flu outbreak appears to have killed dozens of people in Mexico and caused mild illnesses in the United States.

The Atlanta-based federal Centers for Disease Control and Prevention and the New York City Department of Health are recommending several steps to prevent the spread of the virus.

• If you have flu symptoms, stay home from work or school to avoid spreading the disease. Do not return until two days after your symptoms are gone.
• Cover your nose and mouth when you cough or sneeze, and wash your hands frequently.
• Go to the hospital if you have severe symptoms such as difficulty breathing, but if your symptoms are mild stay home to avoid spreading the virus to others at the hospital. Read more »

From the infectious diseases meeting: What’s with the vaccine-o-phobia?

PHILADELPHIA – For the folks who promote vaccination, these are trying times. Recently, CNN hosted a segment titled: “Virus or Vaccine: Which is Worse?”

It’s enough to set Paul Offit to ranting, which he did this week at a meeting of the Infectious Diseases Society of America. Offit, a physician who heads the infectious disease division at Children’s Hospital of Philadelphia, has devoted a career to fighting illness. In his job, vaccines are often the most reliable weapon available, and cost-effective to boot. And although it’s astonishingly more dangerous to contract a disease than it is to get vaccinated for it, that message seems to have gotten lost somewhere along the way.

Offit traces this detour back to 1982, when DPT — the shot that prevents diphtheria, tetanus and pertussis – was (wrongly) linked to brain damage. “Three people believed their kids were harmed by the vaccine,” he says.

Offit has compassion for families who have a child who has suffered, whatever the cause may be, known or unknown. But since 1982, it’s been one accusation after another against vaccines. People tried to link the HIB vaccine to diabetes (no evidence), the hepatitis B vaccine to multiple sclerosis (all but one study found no link), and other vaccines to SIDS or autism. Recently, the HPV vaccine — which prevents cervical cancer – got linked to heart attacks and strokes (no proof).

And now the seasonal flu vaccine and H1N1 flu vaccine are being skipped by millions of people who somehow distrust the science that went into making them, even though the illnesses they cause can be fatal. Read more »

H5N1 (avian / bird flu) pandemic educational information

One of the primary concerns is that the virus could quickly spread across countries as various birds follow their migration routes. In response, countries have begun planning in anticipation of an outbreak. While short-term strategies to deal with an outbreak focus on limiting travel and culling and vaccinating poultry, long-term strategies require substantial changes in the lifestyles of the most at-risk populations.

WHO announced on November, 16, 2005 that an outbreak is most likely to hit the Hong Kong Special Administrative issue by mid-December of this year. “If it were to hit in a highly residential area like Tin Hau, it would be sure to spread like wildfire.” Dr. N Column, Head of Epidemic Prevention announced.

The WHO divides a pandemic into six phases, ranging from minimal risk of an outbreak to full scale pandemic. Most health authorities categorize the situation as of 2005 at Phase 3, by which is meant that human infections of a new sub-type has occurred but there is little evidence of sustained human-to-human transmission.

Avian Influenza (Bird Flu)

Avian influenza, or �bird flu�, is a contagious disease of animals caused by viruses that normally infect only birds and, less commonly, pigs. Avian influenza viruses are highly species-specific, but have, on rare occasions, crossed the species barrier to infect humans.

In domestic poultry, infection with avian influenza viruses causes two main forms of disease. The so-called �low pathogenic� form commonly causes only mild symptoms (ruffled feathers, a drop in egg production) and may easily go undetected. The highly pathogenic form is far more dramatic. It spreads very rapidly through poultry flocks, causes disease affecting multiple internal organs, and has a mortality that can approach 100%, often within 48 hours.

Influenza A viruses have 16 H subtypes and 9 N subtypes. Only viruses of the H5 and H7 subtypes are known to cause the highly pathogenic form of the disease. On present understanding, H5 and H7 viruses may circulate and infect poultry flocks in their low pathogenic form. The viruses can then mutate, usually within a few months, into the highly pathogenic form. This is why the presence of an H5 or H7 virus in poultry is always cause for concern, even when the initial signs of infection are mild. Read more »

Anemia

Background
Anemia, like a fever, is a symptom of disease that requires investigation to determine the underlying etiology. Often, practicing physicians overlook mild anemia. This is similar to failing to seek the etiology of a fever. The purpose of this article is to provide a method of determining the etiology of an anemia.

Anemia is strictly defined as a decrease in red blood cell (RBC) mass. Methods for measuring RBC mass are time consuming, are expensive, and usually require transfusion of radiolabeled erythrocytes. Thus, in practice, anemia is usually discovered and quantified by measurement of the RBC count, hemoglobin (Hb) concentration, and hematocrit (Hct). These values should be interpreted cautiously because they are concentrations affected by changes in plasma volume. For example, dehydration elevates these values, and increased plasma volume in pregnancy can diminish them without affecting the RBC mass.
Pathophysiology
Erythroid precursors develop in bone marrow at rates usually determined by the requirement for sufficient circulating Hb to oxygenate tissues adequately. Erythroid precursors differentiate sequentially from stem cells to progenitor cells to erythroblasts to normoblasts in a process requiring growth factors and cytokines. This process of differentiation requires several days. Normally, erythroid precursors are released into circulation as reticulocytes.

Reticulocytes remain in the circulation for approximately 1 day before reticulin is excised by reticuloendothelial cells with the delivery of the mature erythrocyte into circulation. The mature erythrocyte remains in circulation for about 120 days before being engulfed and destroyed by phagocytic cells of the reticuloendothelial system. Read more »

Rabies

Background
Rabies is a viral disease that affects the CNS. The genus Lyssavirus contains more than 80 viruses. Classic rabies, the focus of this article, is the prototypical human Lyssavirus pathogen. Ten viruses are in the rabies serogroup, most of which only rarely cause human disease. The genus Lyssavirus, rabies serogroup, includes the classic rabies virus, Mokola virus, Duvenhage virus, Obodhiang virus, Kotonkan virus, Rochambeau virus, European bat Lyssavirus types 1 and 2, and Australian bat Lyssavirus. In 1997, an unusual bat Lyssavirus caused a brief outbreak of a rabieslike illness in Australia.

The fatal madness of rabies has been described throughout recorded history, and its association with rabid canines is well known. For centuries, dog bites were treated prophylactically with cautery, unfortunately, with predictable results. In the 19th century, Pasteur developed a vaccine that successfully prevented rabies after inoculation and launched a new era of hope in the management of this uniformly fatal disease. Rabies is recognized as a zoonosis worldwide. Animal-control and vaccination strategies currently supersede postexposure prophylaxis in preventing the spread of rabies. Through such programs, rabies has been eliminated in several nations and some areas in the US territories.

Human rabies reflects the prevalence of animal infection and the extent of contact this population has with humans. Less than 5% of cases in developed nations occur in domesticated dogs; however, unvaccinated dogs serve as the main reservoir worldwide. Undomesticated canines, such as coyotes, wolves, jackals, and foxes, are most prone to rabies and serve as reservoirs. These reservoirs allow rabies to remain an indefinite public health concern, and ongoing public health measures are critical to its control. Raccoons, skunks, and insect-eating bats remain the prime vectors in the United States, followed by cats and cattle. Increasingly in the United States, the source of exposures cannot be identified, but the risk of death from rabies is exceedingly low, with fewer than 5 cases documented per year. Opossums are rarely infected and are not considered a likely risk for exposure. Read more »