OVERVIEW

What is congenital tuberculosis?

Congenital tuberculosis refers to a congenital infectious disease caused by the mother having a tuberculosis infection, where Mycobacterium tuberculosis invades the fetus during pregnancy.

Congenital tuberculosis can lead to neonatal death, with a mortality rate of about 50%, making it a serious disease that threatens newborns' lives. Women of childbearing age with tuberculosis infection should receive standardized anti-tuberculosis treatment to avoid affecting neonatal health.

Is congenital tuberculosis common?

Congenital tuberculosis is not common and is considered a rare disease. According to statistics, only about 400 cases were reported worldwide in 2008.

However, the number of tuberculosis patients in China is relatively high and has been increasing year by year. In 2017, it was estimated that there were 889,000 new tuberculosis cases nationwide, with an incidence rate of 63 per 100,000. Therefore, congenital tuberculosis should still be taken seriously.

SYMPTOMS

What are the manifestations of congenital tuberculosis?

Infants with congenital tuberculosis may exhibit symptoms immediately after birth or develop them several days later.

The symptoms are nonspecific and include fever, cough, rapid breathing, abdominal distension, cyanosis (bluish lips or skin), jaundice (yellowing of the skin or whites of the eyes), refusal to feed, convulsions, and vomiting.

The disease progresses rapidly. Without prompt and targeted treatment, the infant may quickly develop organ failure, leading to death.

CAUSES

What Causes Congenital Tuberculosis?

The pathogenic bacteria of tuberculosis is Mycobacterium tuberculosis.

Congenital tuberculosis occurs when a mother has a tuberculosis infection, and the Mycobacterium tuberculosis infects the fetus. The bacteria can infect the fetus in two ways:

• Entering the fetus through the bloodstream: If the mother's blood contains Mycobacterium tuberculosis, the bacteria can cross the placental circulation into the fetus and then spread to various organs through the fetal bloodstream.
• Entering the fetus through amniotic fluid: Mycobacterium tuberculosis can infiltrate the placenta, contaminating the amniotic fluid. When the fetus swallows the amniotic fluid, the bacteria enter the digestive tract and lungs, subsequently spreading to other organs.

Will a Pregnant Woman with Tuberculosis Always Infect the Fetus?

Not necessarily. While many mothers have tuberculosis, congenital tuberculosis is relatively rare because maternal tuberculosis does not always transmit to the fetus.

If the pregnant mother is in the "hematogenous dissemination stage" of tuberculosis (where the blood contains a large amount of Mycobacterium tuberculosis), or if there are tuberculous lesions in the placental tissue, or if the mother has tuberculous endometritis, the risk of congenital tuberculosis in the fetus increases.

DIAGNOSIS

What tests are needed for congenital tuberculosis?

If a newborn presents with uncontrollable pneumonia, unexplained hepatosplenomegaly, or sterile otitis media, congenital tuberculosis should be suspected. As many specimens as possible should be collected to detect Mycobacterium tuberculosis, including gastric fluid, cerebrospinal fluid, pus from lesions, bronchoalveolar lavage fluid, and stool.

Additionally, HIV screening, chest X-ray, and placental pathology should be performed.

It is worth noting that the tuberculin skin test (PPD test), commonly used for diagnosing tuberculosis in adults, often yields positive results only three weeks after infection. Early PPD testing in newborns may produce false-negative results, so it cannot be relied upon for diagnosing congenital tuberculosis.

What is the purpose of the tests for congenital tuberculosis?

• Collecting specimens to detect Mycobacterium tuberculosis: Obtaining gastric fluid, cerebrospinal fluid, pus from lesions, bronchoalveolar lavage fluid, and stool to identify Mycobacterium tuberculosis provides strong evidence for diagnosing congenital tuberculosis. However, the bacteria are difficult to detect, so multiple and diverse specimens should be collected.
• HIV screening: HIV is the pathogen causing AIDS. Tuberculosis and HIV infections often coexist, so newborns suspected of congenital tuberculosis should also undergo HIV screening.
• Chest X-ray: This can aid in diagnosing congenital tuberculosis. Although typical tuberculous changes may not appear on X-rays, the test should still be performed to support diagnosis.
• Placental pathology: Examining the placenta for tuberculous lesions can help diagnose congenital tuberculosis if such lesions are found.
• Lumbar puncture: Since congenital tuberculosis can cause central nervous system infections like meningitis or encephalitis, a lumbar puncture should be performed to collect cerebrospinal fluid for testing if these conditions are suspected.

What should congenital tuberculosis patients know about lumbar puncture?

If a lumbar puncture is required for cerebrospinal fluid testing, parents should understand that it is a minimally invasive procedure where the doctor collects cerebrospinal fluid from the lower back. However, the procedure is not complex and is commonly performed. When conducted properly, it poses little risk to the child. Cerebrospinal fluid is continuously produced, so extracting a small amount for testing will not cause deficiency or harm.

Is congenital tuberculosis easy to diagnose?

Diagnosing congenital tuberculosis is challenging because detecting Mycobacterium tuberculosis in specimens is difficult. In 37.9% of cases, congenital tuberculosis is confirmed only through autopsy.

TREATMENT

Which department should congenital tuberculosis patients visit?

Neonatology, Infectious Diseases, or Tuberculosis Specialty.

How is congenital tuberculosis treated?

Once congenital tuberculosis is confirmed, anti-tuberculosis treatment should begin promptly. Standard treatment requires combination therapy with sufficient dosage and duration, typically lasting 9–12 months. Regular follow-ups are necessary to evaluate efficacy and monitor for drug side effects.

Additionally, adequate nutritional support should be provided to prevent organ failure in the baby.

If the central nervous system is infected, treatment involves more diverse medications and an extended course.

Does congenital tuberculosis require hospitalization?

Yes. Initial treatment may involve intravenous anti-tuberculosis drugs. Once the treatment plan is stabilized and switched to oral medication, the patient can be discharged for home care with regular outpatient follow-ups.

Parents should note that congenital tuberculosis is a chronic disease with strict and prolonged treatment. It is crucial to adhere to the prescribed drug dosage, frequency, and timing without missing doses or altering treatment to avoid failure.

Do children with congenital tuberculosis need regular follow-ups after discharge?

Yes. Follow-ups assess treatment efficacy, screen for drug side effects, and check for organ dysfunction. Patients should be monitored at both tuberculosis specialty clinics and pediatric clinics to evaluate normal developmental progress.

DIET & LIFESTYLE

What should children with congenital tuberculosis pay attention to in their diet?

If the mother has open tuberculosis (highly contagious and can spread through droplets), she should be isolated and receive standardized treatment. Contact with the child and others should only resume after she is no longer contagious.

If the mother does not have open tuberculosis, breastfeeding is possible while taking standard anti-tuberculosis drugs (first-line anti-tuberculosis drugs do not affect breastfeeding; if less common second-line drugs are used, consult a tuberculosis specialist to confirm whether breastfeeding is safe). Tuberculosis bacteria are not transmitted through breast milk. However, it is important to note that the mother should also undergo HIV screening. If she is co-infected with HIV, breastfeeding is not recommended.

What should children with congenital tuberculosis pay attention to in daily life?

• Take medication on time and in the correct dosage, and complete the full course of treatment.
• Attend regular follow-up appointments at the clinic.

With standardized treatment, congenital tuberculosis can be cured. However, reducing, stopping, or changing medication without medical guidance may lead to treatment failure and increase the difficulty of recovery.

PREVENTION

Can Congenital Tuberculosis Be Prevented?

Congenital tuberculosis can be prevented.

• Women of childbearing age with tuberculosis infection should receive standardized treatment to control the condition as soon as possible and avoid active tuberculosis.
• If a pregnant woman is diagnosed with tuberculosis before pregnancy and is undergoing medication control, she should not stop treatment on her own during pregnancy. Instead, she should continue anti-tuberculosis therapy. Under a doctor's guidance, the treatment can be adjusted to medications suitable for pregnant women to minimize the impact on the fetus.
• If there is a tuberculosis patient in the household, women who are planning pregnancy or are pregnant must avoid infection by not contacting the patient and urging the patient to undergo standardized treatment. Women in these stages who have been exposed to tuberculosis patients should be screened for tuberculosis infection via a tuberculin test.
• If the spouse or the woman herself has HIV infection, it is important to check for concurrent tuberculosis infection.
• If a pregnant woman has active tuberculosis infection (positive sputum smear, symptoms such as fever, night sweats, weight loss, or positive changes on a chest X-ray), anti-tuberculosis treatment should be initiated promptly, even during pregnancy, to prevent transmission to the fetus and the occurrence of congenital tuberculosis.

Vaccination with BCG during pregnancy does not reduce the incidence of congenital tuberculosis.