In developing countries, an estimated 1.3 billion episodes of diarrhea occur annually and 3.2 million children under 5 years of age die from diarrhea-related causes. This monograph details the mechanisms of digestive absorption and malabsorption and updates knowledge of infective vectors, and then reviews current preventive and treatment strategies. Three treatment plans are outlined, with the choice based on an objective review of the child's physical signs and degree of dehydration. Home treatment of diarrhea should be governed by three principles: increased fluid intake, continuation of a normal diet, and monitoring for signs of dehydration. Since the incidence and course of diarrhea are influenced by nutritional and health status, immune status, household hygiene and socioeconomic/educational levels, housing, water supplies, and waste disposal, any initiatives around this child health issue must be multisectorial. Equally important to the design of public health interventions in a given area as epidemiologic and clinical analyses is an understanding of community behavioral patterns and attitudes.
Diagnosis of tuberculosis (TB) in children is usually based on presumptions from several elements: clinical picture and course, x-rays, tuberculin test, and culture of pathology later on. TB is usually found in a child because of symptoms of primary disease, or through case-finding of a contact. TB is children is often a primary infection and may be gradual or acute in onset. Some of the symptoms of primary TB are low-grade fever, pallor, fatigue, and anorexia. The child may have erythema nodosum, a yellow module on the conjunctiva, hilar or mediastinal lymphadenopathy, a primary TB complex on the lung (3-10 mm), segmental density, or a positive PPD test. Children with pulmonary disease do not have adult-type cavity lesions, but may have a primary cavity that drains into the bronchi, mechanical complications, fistulas, or atelectasis. Acute TB often appears as meningitis. The pathognomonic signs are cerebrospinal fluid high in lymphocytes with very high albumin (0.6-2 g) and low glucose (0.4-0.2 g/l). TB organisms are rarely seen, but may be cultured. TB meningitis is also notable for choroidal tubercles, which are yellow nodules visible in the fundus. These presumptive signs, as well as increasing neurological findings, prompt immediate treatment. Children also may have acute miliary TB, marked by high fever, gastrointestinal symptoms, hepatosplenomegaly, dyspnea, cyanosis, and respiratory distress, with characteristic diffuse grainy spots on the chest x-ray. A child may have both conditions and may also have localized TB infection elsewhere. Thus, clinical findings may point to possible cultures of urine, gastric lavage, pleural fluid or biopsy, pericardial fluid, bone marrow, or ascitic fluid, any of which should be cultured to rule out other causes. The most common sites for extra-pulmonary TB are cervical nodes, spine, knee. shoulder, hip and peritoneum. Pelvic and urinary tract infections are rare in children.
The situations when prophylactic antibiotics should be given to children in developing countries where BCG vaccination is common are explained. In most countries, 80-90% of children have been vaccinated with BCG by the age of 1. Since BCG makes a tuberculin (PPD) test moot, because all BCG-vaccinated persons have positive PPD tests, the only children in developing countries who can be diagnoses with TB are those who are vaccinated and live in close contact with a TB infected person. The only prophylactic medication recommended for children is daily isoniazid, 5 mg/kg for 6 months. Preventive medication is never given to healthy BCG-vaccinated children. The multi-drug regimen is not appropriate because young children have relatively few Mycobacterium bacilli, and developing countries cannot even afford to treat infected adults with these regimens. The only situations for treating children prophylactically are: 1) healthy children, under 5, not BCG vaccinated, and tuberculin positive; 2) healthy children, age 5-14, tuberculin positive with documented negative PPD test within 2 years, and 3) age 1, not BCG vaccinated, recently diagnosed as tuberculin positive. In an infant living in close contact with an infected source, a PPD test is done after 3 months of treatment with isoniazid, and if positive, treatment is continued for another 3 months. If the PPD test is still negative, the BCG vaccination is given.
Treatment guidelines for tuberculosis in children, issued by the International Union against Tuberculosis and Lung Diseases in 1987 and 1990 and the World Health Organization Tuberculosis Unit for the Treatment of Tuberculosis in Adults and Children in 1991, are explained. The combination drug treatments are similar to those recommended for adults, except that ethambutol is not normally given to children too young to have vision tests. Another difference is that the 2 or 3 times weekly dosing schedules are not usually followed in young children, because they cannot take so many tablets orally. The treatment schedule involves an initial intensive phase with 4 drugs, isoniazid, rifampicin, pyrazinamide, and streptomycin, followed by a consolidation phase lasting 6-8 months without pyrazinamide. Alternatively, a longer regimen without isoniazid taken for 4-8 months, can be used for the more common paucibacillary forms. In case of suspected cure failure or relapse, another regimen of 5 drugs must be restarted, including isoniazid, rifampicin, ethambutol, pyrazinamide, and streptomycin for 8 months. These multi-drug regimens are continued until definitive testing shows the TB is not resistant, when some drugs may be dropped. Aspects of management of the child's care are reviewed, such as types of clinical exams; family education; dosage; giving prednisone in cases of meningitis; miliary tuberculosis; serosis; or lobar, segmental, or bronchial involvement. Recommendations are given for supervision and delegation of drug administration; follow-up visits; treatment of localized TB in joints, pleura, or pericardium, and the importance of notification of childhood TB. These drug regimens, if followed, correctly, will cure TB in 100% of children, but the sequelae will depend on the extent of initial infection.
Bacteriological diagnosis of tuberculosis (TB) in children is not as easy as simply observing or culturing sputum, since children rarely expectorate TB organisms; instead direct smears of other specimens may be possible, or culture is attempted. The most common locations of TB in young children were primary infections of mediastinal nodes, pulmonary infections with or without cavitation, or extrapulmonary infections of the pleura, joints, pericardium, peritoneum, or elsewhere. In most cases, drug treatment must be started before culture results are returned. Specimens of suspected pulmonary TB are taken by gastric lavage or laryngeal swab in early morning, or by induced coughing, with protection for health workers. Specimens can also sometimes be obtained from urine, open lesions, puncture of the pleura, cerebrospinal fluid, or ascites. Smears for TB are stained with Ziehl-Neelsen acid-fast technique or auramine fluorescent strain. Mycobacterium tuberculosis can be cultured directly on Lowenstein-Jensen medium, if a pure culture is anticipated, as from cerebrospinal fluid. If the organisms are mixed with normal flora, they can be selected by pretreatment with 4% NaOH or a detergent. There are highly technological methods for isolating and identifying M. tuberculosis, such as radiometric culture techniques, or assaying tuberculostearic acid, both of which require expensive equipment, and methods still in research and development, such as an ELISA and a DNA probe.
