Monday, June 23, 2008

Vertical and Horizontal

Vertical transmission of a disease means that it can be passed through the placenta from mother to child during pregnancy. This mode of Lyme transmission makes sense to me. I see a lot of families where many of the children are infected, as well as the mother. Currently, there is family with 4 daughters, all of whom have Lyme disease. Their mother died at an early age of atypical multiple sclerosis. The family always suspected something else was going on. Unfortunately, many doctors diagnosis MS on the basis of MRI findings. Today, on my desk, a brain MRI report states that the findings are compatible with Lyme, but that MS is more likely. The patient has Lyme. Syphilis may be passed vertically from mother to child and cause a congenital syndrome seen at birth. Lyme does not cause obvious abnormalities seen at birth, to the best of our knowledge. It is a slow infection. Symptoms develop over time. Children become symptomatic at various ages from pre-school to early adulthood. Still based on what is known of the biological behavior of Borrelia and other spirochetes, it makes sense that vertical transmission occurs.

Horizontal transmission refers to person to person transmission of an infectious disease. Some believe that Lyme may be sexually transmitted. I believe this is false. Syphilis is transmitted via an open sore on the skin, a chancre with spread of the spirochete through the thin skin or mucous membranes of the genitalia. Lyme generally lives deep in tissues. The rashes which may have active spirochetes near the surface occur on the extremities and trunk. It is nearly impossible to find Lyme bacteria in any body fluids. Other sexually transmitted organisms are present in blood and body fluids. This is not the case for Lyme. Lyme DNA has been shown to be excreted through the urinary tract. After an antibiotic challenge urine PCR testing for Lyme DNA may be positive. This does not mean that intact viable organisms are present in genital secretions. In addition, there are specific factors in the tick bite and in tick saliva which have been shown to be important for infection to occur. Other insects like mosquitoes and flies may be infected with Borrelia, but there is no evidence that bites from these insects transmit the disease to humans. Lyme has a difficult time penetrating the skin barrier. But once it is in the body it has the ability to easily spread to tissues throughout the body. This is why vertical transmission makes sense and horizontal does not.

4 comments:

blymey said...

So based on vertical transmission - I should probably have my son checked for lyme, correct? Especially since I've had lyme for over 20 years.
He has exzema pretty severely in the summer and winter behind the knees and in the creases of the elbows - sometimes showing up on his thighs and during the winter on his face. I look forward to seeing your response.

Lyme report: Montgomery County, MD said...

Many people who are infected with Lyme never develop any symptoms. Some sources have suggested this is true for 40% of infected individuals. I do not know the real numbers. I do not recommend testing unless someone has symptoms which tie in with Lyme disease.
Eczema alone is not a reason to check for Lyme. This is an allergic reaction and not related to Lyme.

Kiki said...

Hi there. I took my three weeks of doxy 1 month before I found out I was pregnant. My twins are now 1 year old and were born 4 weeks early. They developed milk protein induced enterocolotis syndrome diagnosed by 6 weeks old and then reacted the same way to soy formula, and later had the same reaction to rice, sweet potato. They are not eating ANY food now as they have reacted to the things we've tried and the dr. wants us to heal their intestines... They take an amino acid based formula - that is all they have ever tolerated. When they eat/drink other things they have pain, cramping, sleeplessness, and blood and mucus on the stool... do you think this could be Lyme? Should they be tested?

Kiki said...

sorry - they also have GERD, and in the past have not been unable to take certain brands of amino acid formula - my son won't swollow one brand - he gags and chokes and my daughter had delayed gastric emptying on one brand... they tell me the major difference is the long vs. medium chain fatty acids.

my daughter also recently had a dx of giardia which no one understands where it came from. My son did not but he has had 2 cycles of antibiotics due to ear infection...