DEAR ABBY: I just read the letter from the woman whose doctor diagnosed her with chlamydia. She said she had been faithful to her husband for 9 1/2 years, and he claimed to have been faithful to her. She asked if she could have been carrying the disease that long. You told her yes, it was possible.

This situation sounded all too familiar to me. That's why I'm writing. I recently went for a checkup at my local state health department, and was told upon initial examination that I, too, had chlamydia. I had been married for 10 years and had been faithful to my husband, and never did I doubt his faithfulness. I told the nurse this, and she said that the doctor felt no need to run another test to confirm the diagnosis as I had complained of the symptoms and he was 99 percent sure. But if I wanted to be sure which sexually transmitted disease I had, they would take a sample for the test.Then I went home and confronted my husband. He said there was no possibility that this was true. He went to the health department the following day so they could take a sample from him. We were both treated for a week while waiting for our tests to come back. Guess what? They had made a mistake! Both of our tests were negative! Quite a mistake, I might add, as I'm due to deliver our first child in February.

I have since contacted the health department and asked the people there to counsel their staff, as this could have ruined a marriage that was not as strong as ours. Please publish this letter. And sign me . . . RETESTED AND PASSED

DEAR RETESTED: Thank you for writing. Please read on:

DEAR ABBY: This is in reference to the letter from "Suspicious in Arizona," the housewife who, after many years as a faithful wife, was diagnosed as having chlamydia. Her husband also claimed to be totally faithful, but now she was suspicious.

As a researcher in chlamydia, I am deeply concerned that too many rapid tests are being done for diagnosis of chlamydia infection instead of a culture, which is the "gold standard." "Suspicious" may have been tested by one of the tests that are inaccurate an average of 20 percent of the time! These inaccurate tests have victimized many people by creating havoc in their marriages.

Furthermore, I have testified as an expert witness where a father was accused of child abuse because of an inappropriate test. He was subsequently found innocent and released from a penitentiary, after exhausting his savings on lawyers' fees. - DR . RUTH B. KUNDSIN, ASSOCIATE PROFESSOR OF MICROBIOLOGY AND MOLECULAR GENETICS, HARVARD MEDICAL SCHOOL

DEAR DR. KUNDSIN: Thank you for a valuable contribution to this column. The margin for error in testing is shocking. Obviously, tests that are incorrect 20 percent of the time should not be taken. Instead, those to be tested should insist on a culture to assure accuracy. If one is seeking to prove paternity, venereal disease or child abuse, the test must be 100 percent accurate.

Doctors, lawyers, readers - take note.

DEAR ABBY: Concerning the question of who should go to the airport to meet the serviceman who had been overseas for over a year. His wife, alone? Or his parents and his wife? I vote with you, Abby. (His wife and his parents.)

My husband was in the military as a career, and I have shared many a homecoming with parents and children at various times. We are still happily married.

I had a friend whose husband was also in the military. She saved pennies all the time her husband was gone. When he came back, she took the kids with her to meet their dad at the airport. Earlier, she had scattered all the pennies she had saved on the front lawn; when they all got home from the airport, she told the kids they could keep all the money they found. Then she and her husband went inside for some quiet time alone! - AN EX-SEABEE'S WIFE IN BEDFORD, IND.

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