©March 2009

Based upon the high quality education bestowed upon us by the endless stream of crime scene investigation mysteries on television, we learn that one of the first lessons for those trying to catch crooks is to think like the criminal.  If the suspect is a sailor, stake out the marina.  Similarly, when considering how to best find the culprit in an infectious disease, it is helpful to think like the virus or bacteria in question.  What would I do if I were an STI?

Consider what characteristics can lead a germ to end up on the “Ten Most Wanted” list.  First, it is important to recognize that germs are much more likely to create an epidemic if they avoid calling attention to themselves and do not kill their host.  When an illness announces its arrival with large red spots on the face or causes life-threatening symptoms, it can hardly avoid being discovered and arrested.

Similarly, an organism that kills its host is destroying its own meal ticket.  Sometimes this strategy works, but only when the victim showers the environment with germs as the illness progresses.

Causing an infection which allows the victim to go about his or her business while being attracted to and expressing affection for others is an ideal way to guarantee success as a germ.  This is the successful strategy employed by the mononucleosis virus which is also known as the “kissing disease.”

Another germ that takes advantage of this tactic is the Chlamydia bacteria, the most commonly reported infectious disease to health departments in California.  Chlamydia is a sexually transmitted infection (STI) which usually causes very few symptoms.  Chlamydia may cause burning with urination in males or females, or crampy pain and mucous discharge from the vagina in females.  The devastating inflammation that it stirs up in the female organs is the most common cause of female infertility in the U.S.  By causing inflammation in the genital tract, Chlamydia also increases the likelihood that other infections like HIV/AIDS can be transmitted.

For a germ to be successful, it must procure a means of transportation that is dependable.  West Nile Virus found just such a transportation system in the mosquito population.  What better way to assure a trip from host to host than to hitchhike on a vehicle as readily available as mosquitoes in the summer?

The most dependable way to avoid becoming a victim of the germs that cause STIs is to abstain from sexual contact.  Conveying this message to those confused by the discovery of new attractions is, of course, the full time occupation of the parents of adolescents.  From the perspective of the STI, depending upon the gravitational forces that from time to time develop between two human beings is as reliable a method of transmission as there is.

In people who are sexually active, condoms have been shown to reduce the transmission of infection, although different studies have found that the risk of infection is diminished differently for different infectious organisms.  Also, the amount of protection afforded by condoms is very dependent upon proper condom use.  Because reading the package insert is not often a priority at the moment of passion, it is important to learn such things ahead of time.

A second way to prevent STIs from inflicting permanent damage upon the population is to test for the presence of the germs in any person who is sexually active.  This can be done at the time of a routine physical, at the time of a visit to the family planning clinic, or in response to symptoms experienced by a patient.  The test can now be done for the two most common STI germs, Chlamydia and Gonorrhea, simply by collecting a urine specimen.

Another way to protect the public from the effects of STIs is to vaccinate against the Human Papilloma Virus (HPV).  The new HPV vaccine provides protection against four strains of the HPV virus that are responsible for 70% of cervical cancer.  We screen for cancer of the cervix with the Pap Smear obtained every three years after age 21.  After 30 years of age, women should personalize their cervical cancer screening recommendations by discussing it with their health care providers.  The HPV vaccine consists of a series of three doses given after nine years of age.

The surest way to decrease the discovery of crime is to stop looking for criminals and ignore the existence of misconduct.  Infectious organisms would love for the health care system to give up on screening the population for STIs and stop encouraging the use of condoms for people who choose to be sexually active.  Unfortunately, such a course will not make these villains go away.

©January 2009

During immunization campaigns, photos often depict unhappy children sitting obediently on the laps of parents looking reassuring and responsible.  These images often give us a sense that vaccinations are something we impose on those under our charge, such as our children, our pets or our ranch stock.  After emerging from adolescence, adults enjoy a sense of freedom from the need to subject themselves to the indignity of immunizations, similar to the assurance that their last SAT tests are behind them.  This is a fantasy.  The first clue comes in the form of the recommended annual influenza vaccinations for adults, but a growing number of additional vaccinations are available which are also important for adults to include in their health care planning.

First, it is worthwhile to review the theory behind vaccinations.  The immune system is assigned the job of protecting our body from foreign invasion.  It is unfortunate that students learn about the digestive, circulatory and nervous systems in fourth grade, but the immune system does not often show up in text books until later.  Like the heart, it works 24 hours a day, 365 days a year, except leap years, to prevent a virtually endless list of villains from causing infections.

The immune system learns to recognize these villains through experience.  Vaccinations provide this experience, either by giving our immune systems a sniff of dead fragments of viruses or bacteria (“inactivated” vaccines), or by giving our immune systems experience with a living distant cousin of the villainous germs (“live” vaccines) so that our body’s law enforcement can recognize the nasty ones when and if they show up.

Public Health experts have noted that there is indeed a tendency for populations with higher annual influenza vaccination rates to develop an increasing resistance to influenza penetration.  In other words, there appears to be some benefit to groups of people from prior years’ influenza vaccinations.  Nevertheless, because of the slippery behavior of this particular virus, repeat annual influenza vaccinations are still the recommended rule.

Some people confuse the influenza vaccine and the so-called “pneumonia” vaccine.  There is a bacteria called the “pneumococcus” which causes a dangerous form of pneumonia (lung infection), particularly in seniors who are disabled by other conditions of older age.  Infection from this bacteria can be prevented with the “pneumococcal vaccine,” AKA the “pneumonia vaccine.”  It is generally recommended that seniors 65 years of age and older receive two pneumonia vaccines one year apart.

Any adult who seeks emergency care for a cut or puncture wound is familiar with the question, “When was your last tetanus shot?”  A wound should always be washed with soap and water.  But if a person suffers a dirty wound, like a pitchfork to the foot or a barbed wire puncture in a field, a tetanus vaccination should have been obtained within the last five years.  If the wound is relatively clean, like a cut while washing dishes, then an interval of ten years is usually satisfactory.

If a person 11 years or older has never had a booster dose of tetanus that included inactivated pertussis vaccine, then the next tetanus shot should include the pertussis booster, in a shot called the “Tdap.”  This is because we have learned that immunity to pertussis (whooping cough) begins to disappear during adulthood.  We have learned this by experience.

The Human Papilloma Virus (HPV) causes cervical cancer.  About 12,000 women develop invasive cervical cancer each year in the U.S. and approximately one third will die of this disease.  The HPV vaccine is the first vaccine developed to prevent cancer.  It should be given in two doses if the patient’s first dose is given between 9 and 14 years of age, but if the patient is 15 to 26 years of age, then three doses are recommended.  There has been over a 60% drop in vaccine-type HPV infections in teen girls in the U.S. since the HPV vaccine was first released in 2006.

The varicella vaccine is used to prevent chicken pox in those who have never had the illness.  In seniors, the varicella virus that causes chicken pox can return from hiding within our own bodies and show up as a disease called “shingles” or “Herpes Zoster.”  This disease can be very painful and result in disabling symptoms.  Therefore, a shingles vaccine should be obtained by seniors 60 years and older as two doses of Shingrix, a new Zoster vaccine, 2 to 6 months apart.

Finally, the Measles, Mumps and Rubella vaccine should be obtained at least once during adulthood before age 50 to assure protection against these viral illnesses.

Keeping this information straight becomes ever more difficult as new vaccines are developed to protect us from the nefarious interests of unfriendly viruses and bacteria.  One of the most important responsibilities of public health is to help keep this information at your fingertips.