Why so much research into infectious diseases?

Proven content

During the preparation of a woman for pregnancy, a series of tests is performed for many infectious diseases – both bacterial and viral. Why?

Infections at different stages of pregnancy may result in miscarriage or premature delivery, inhibition of intrauterine development of the fetus, low birth weight of the newborn, stillbirth or death of the newborn. There is also a risk of infection of the fetus or newborn baby and of developing an infectious disease or birth defects in the baby. Hence the widespread prophylaxis of pregnant infections.

Syphilis

Syphilis is an infectious venereal disease and is therefore sexually transmitted. The place where the pale spirochete enters the body is damaged mucosa or skin. In adults, syphilis has three stages: primary, secondary and tertiary syphilis. Syphilis in a pregnant woman is a threat to the developing fetus and then to the newborn. In fact, from the 8th week of pregnancy, there is a possibility of transmission of the infection from the mother to the fetus via the placenta. The greatest risk of infection occurs in the second and third trimesters of pregnancy. In the period of primary maternal syphilis, the risk of transmission to the fetus is 50%, and in 50% of cases, the infection is fatal. In contrast, the risk of congenital syphilis in a newborn is 50%. Congenital syphilis occurs in about 10% of newborns with latent mother’s syphilis.

In newborns with early congenital syphilis, the first symptoms appear after 10-14 days of life. The child then develops a maculopapular rash. The complication of the disease may be inflammation of the choroid, retina and iris of the eye, and inflammation of the bones and cartilage, which may result in pseudo-paralysis. An untreated child may have the characteristic so-called Hutchinson’s teeth, keratitis – leading to blindness, inflammation of the VIII cranial nerve – resulting in deafness, saddle nose, saber-like limbs. In order to prevent intrauterine infection with syphilis, pregnant women should be tested for this disease, and if the result is positive – treatment with penicillin should be initiated for both the woman and all her sexual partners. All newborns are also tested for syphilis – they are also treated with penicillin, if necessary.

Streptococcus agalactiae

For several years, diagnostics of pregnant women has been carried out for the presence of this bacteria in the reproductive tract. Usually, the tests are performed around the 35th week. pregnancy. The material for examination is collected in a similar way as in the case of cytology. Approximately 20% of women were found to be asymptomatic carriers of Streptococcus agalactiae. The presence of this bacterium is not indifferent to a woman. It can cause urinary tract infections, usually asymptomatic. It can also cause endometritis, as well as lead to bacteremia – especially in patients who have undergone cesarean section – and to wound infections. Infants are infected during childbirth, but can also be infected through the placenta through the bloodstream or ascending from the woman’s genital tract. Infected with Streptococcus agalactiae, premature and low-birth weight neonates were found to die twice as often as normal-weight mature neonates. The risk of the baby being infected with this bacterium increases in the case of premature (i.e. 12-18 hours before delivery) of the amniotic fluid drainage. In premature babies and low weight children, Streptococcus agalactiae infection mainly affects the lung tissue, but may also involve the central nervous system or be sepsis. The fulminant form of infection is extremely rare, with septic shock and neonatal mortality of up to 50-70%. The late form of the infection develops after the first week of a child’s life, and its mortality is 15-30%. The most common infection is meningitis. There is no significant benefit in treating a pregnant woman and her partner (sexually transmitted infection) during the antenatal period. The implementation of intravenous ampicillin therapy 4 hours before delivery and the repeated doses of the antibiotic every 2 hours is much more effective.

Chlamydia trachomatis

This microorganism is one of the sexually transmitted germs. The urethra is the focus of infection in both sexes, and in women also the cervix. Infection of the male urethra is usually asymptomatic. If symptoms do occur, they appear as a thin, clear or mucopurulent discharge from the outer opening of the urethra. If a man is an asymptomatic carrier of chlamydia, he is a source of infection for the woman. The germs of the prostate gland can also lead to infertility. About 20-40% of women of childbearing age are infected with Chlamydia trachomatis. Infection may result in an inability to become pregnant, and in pregnant women it may lead to premature rupture of the membranes and the birth of a premature baby. Chlamydia infection can also inhibit the intrauterine development of the fetus. Infection with this organism is much more common in young women with a lower socioeconomic status and in those who use oral contraception. Treatment is based on the oral administration of antibiotics: erythromycin, amoxicillin or clindamycin. Inclusive conjunctivitis occurs in newborns infected with Chlamydia trachomatis in the first 2 weeks of life, and 10-20% of cases develop pneumonia in the next 3-4 months.

Infection caused by organisms of the genus Mycoplasma

Mycoplasmas cause inflammation of the vagina, urethra and cervix in women. In men, however, they are the cause of urethral and prostate infections as well as pyelonephritis. It is difficult to prove the direct influence of vaginal infections on the occurrence of miscarriage or preterm labor associated with infection of the membranes of the membranes. However, if a pregnant woman is diagnosed with mycoplasma infection, appropriate antibiotic treatment should be initiated. Newborns become infected when they pass through the birth canal during labor, and the infection can manifest as pneumonia, sepsis, or meningitis.

Fungal infections

Fungi are part of the physiological flora of the vagina. However, the acidic environment of this organ and the competitive influence of other microorganisms ensure a state of specific balance, preventing the excessive multiplication of fungi, so that vaginal mycosis does not develop. In pregnant women, the carrier of fungi strains reaches 50%. The factors disturbing the balance of the vaginal microflora described above include, among others. diabetes, a high-carbohydrate diet, deficiency of iron or B vitamins, immunological defects – i.e. weakened immunity, long-term antibiotic therapy, the use of other drugs that impair immunity, such as cytostatics or steroids. Vaginal fungal infection can lead to inflammation of the membranes and ruptures, resulting in miscarriage or preterm labor. Newborns with intrauterine fungal infection are born with dermatophytosis, endometritis, pneumonia, or meningitis. That is why it is so important to treat any vaginal fungal infection as often as necessary – especially during pregnancy, when it happens that these infections persistently recur.

Trichomoniasis vaginal

Trichomoniasis is a sexually transmitted parasitic disease. The causative microorganism lives in the urogenital tract – both in men and women. In many women, trichomoniasis is asymptomatic, and if symptoms appear, they are soreness and congestion, swelling and infiltration of the vaginal mucosa. In acute conditions, there are characteristic foamy vaginal discharge, itching of the vulva, pain and burning sensation when urinating. Bartholin’s gland and / or tubular glands may become inflamed, sometimes with severe pain and fever. A newborn baby becomes infected during childbirth. The infection may result in the development of cystitis, pneumonia, and in girls – inflammation of the vestibule and vagina. Metronidazole is the drug of choice, but it should not be used in the first trimester of pregnancy. Then it should be replaced with clotrimazole.

Viral infections

Rubella

Rubella virus is spread by airborne droplets. During the season, it occurs in large numbers of people. Approximately 2 weeks after infection, a mild infection with pseudo-flu symptoms and a characteristic rash develops. This form of the disease, as a rule, affects toddlers 5-14 years old. In rare cases, there are complications in the form of meningitis or thrombocytopenic purpura. However, the infection is much more dangerous when it concerns pregnant women who have never had contact with the rubella virus before, and therefore do not have specific immunity against it. The rubella virus is highly teratogenic. It crosses the placenta to the fetus and may cause miscarriage, fetal death, death of the newborn, or birth defects. The earlier the maternal infection occurred in the course of pregnancy, the higher the risk of the consequences of the infection in the fetus. The highest risk is in the period up to the 17th week of pregnancy. The most common complications of infection in a developing fetus are: cataracts, deafness, hydrocephalus, mental retardation, and congenital heart defects. As a result of infections that occurred after the 17th week of pregnancy, temporary disturbances in the development of the fetus are observed. Due to the above-mentioned risks, every woman planning a pregnancy should have the level of antibodies to the rubella virus tested. The lack of antibodies is an indication for rubella vaccination at least 3 months before the planned pregnancy. If the pregnant woman has not been ill with rubella or has not been vaccinated against this disease, and in the first trimester of pregnancy, she has been in contact with a person suffering from rubella, then – after prior determination of the antibody titer – specific immunoglobulin may be administered to her up to 7 days after the potential infection.

Herpes (

A person can catch two types of the herpes virus. The first, non-genital, causes infections of the mucous membranes and skin. Most often it appears around the mouth. The second type, genital, causes infection within the reproductive organ. It is sexually transmitted. The incubation period is approximately 7 days. If a pregnant woman has a systemic infection with this virus with an increase in temperature, it may result in premature labor. Infection of the fetus in the perinatal period is associated with an increase in mortality, and surviving fetuses may develop encephalitis, eye retinitis, liver damage, and skin lesions. Infection in early pregnancy can lead to miscarriage. A newborn baby becomes infected while passing through the genital tract during childbirth. Such an infection does not have a characteristic course. In the case of primary generalized infection of a pregnant woman with herpes virus accompanied by fever, the patient should be treated in a hospital setting, isolated and antiviral drugs should be administered orally or intravenously. If a woman infected with herpes drains prematurely, it is recommended to complete delivery within 6 hours – in the case of genital herpes – by caesarean section, and in the case of herpes simplex – by vaginal delivery. A newborn of a mother with herpes I and II can be breastfed. However, it is recommended to use an increased hygiene regime.

Chickenpox, shingles (Varicella zoster)

The infection of the fetus with herpes zoster occurs during the mother’s viremia period. Viruses cross the placenta. The most serious complication of chickenpox in a pregnant woman is pneumonia. If the infection occurred before the end of the 20th week of pregnancy, miscarriage or death may occur. In 1-2% of cases, intrauterine infected children develop congenital varicella syndrome, which causes skin lesions, hypoplasia of the limbs, paralysis with muscle atrophy, cataracts, and brain atrophy. Infection of the mother after the 20th week of pregnancy may result in the development of infantile herpes zoster in the newborn in early childhood. Finally, infection of a pregnant woman at the end of pregnancy can cause chickenpox in the newborn. Thus, the later the period of pregnancy in which the mother becomes infected, the milder the course of the infection and the less health consequences for the fetus and newborn baby. If a pregnant woman, who has not had chickenpox before, is confronted with this disease, she may be given interventional specific immunoglobulin.

Cytomegalia

The source of cytomegalovirus infection is saliva, urine, tears, blood, breast milk, semen and cervical secretions of infected persons. Most infection occurs through sexual contact, kissing, or contact with young children. Of course, it can also happen during medical procedures, e.g. blood transfusions. The primary infection is uncharacteristic with fever and enlarged lymph nodes. Rarely, interstitial pneumonia, meningitis, liver, myocarditis, thrombocytopenia and haemolytic anemia occur. Pregnancy may cause a reduction in immunity, activation of the virus present in the body and secondary infection – most often, however, asymptomatic. Young children are the main source of infection for pregnant women. Antibodies present in the serum of a pregnant woman do not protect against fetal infection in the course of secondary infection. The newborn is infected during childbirth, via the ascending pathway from the cervix. In the case of primary maternal infection, the fetus is infected through the placenta. Intrauterine infected children secrete cytomegalovirus with saliva for 4 years, and perinatal infected children for 2 years. Newborns of mothers with a primary infection – if they survive – are born prematurely and with low birth weight. Mortality in newborns with congenital cytomegaly is 20-30%. Surviving neonates suffer from microcephaly, retinitis and choroiditis, hepatic and spleen enlargement, intracranial calcifications, mental retardation, deafness, haemolytic anemia, etc. So far, no effective method of cytomegaly treatment has been known – neither in the mother, fetus or neonate. .

HIV

In Poland, there is a health program that allows every pregnant woman to have an HIV test free of charge. Unfortunately, the small percentage of future mothers who took advantage of this opportunity indicates an evident lack of knowledge about the risks of HIV infection and the still lingering belief that this infection affects marginalized people, drug addicts and homosexuals. However, this view is not confirmed, and epidemiological data show that the vast majority of new cases are heterosexuals. The transmission of the virus from mother to child can occur both during pregnancy – through the placenta, during childbirth – through the contact of the newborn with the mother’s blood and secretions, and finally – through the mother’s milk after delivery. The newborn’s blood contains maternally derived antibodies to HIV, which can be effective during the first 15 months of a baby’s life and may be difficult to diagnose. If a pregnant woman is HIV positive, she must be under strict medical supervision. It is necessary to constantly monitor the number of CD4 lymphocytes and depending on their number – further actions. With CD4 levels below 200 / mm³ it is necessary to include antiviral drugs and prophylactic therapy with antibiotics. Antiviral drugs are administered from the 14th week of pregnancy, which significantly reduces the risk of virus transmission through the placenta to the fetus. An infected mother should not breastfeed after giving birth. The exceptions are African countries, where the risk of neonatal death due to malnutrition and dehydration is much greater than the risk of HIV infection through food.

Text: lek. med. Ewa Zarudzka