Infectious diseases

Routine antenatal screening can detect some potentially serious infectious diseases or susceptibility to infection and allow intervention to prevent adverse outcomes. However, screening programmes can only be justified if appropriate criteria are met for the quality of laboratory tests and interventions. For many infections that are associated with adverse maternal or fetal effects, there are no suitable, cost-effective methods of screening or prevention. However, early diagnosis of infection in high-risk women or those with symptoms can allow preventive intervention. Acute febrile illness or other symptoms consistent with infection during pregnancy should be investigated more diligently than in a non-pregnant woman. Early diagnosis of an apparently trivial maternal infection may prevent serious fetal disease. When the diagnosis of maternal infection is made, appropriate action depends on the nature of infection and the stage of pregnancy at which it occurs. The results of serological test should be confirmed, preferably by a reference laboratory, by retesting the original specimen(s) and/or testing further specimens, as appropriate. Management decisions generally should be made in consultation with an infectious disease physician or clinical microbiologist with experience of infectious diseases in pregnancy.

The perinatal autopsy: a contemporary approach

As autopsy rates in general hospitals decline, interest in the perinatal autopsy continues to rise, reflecting the emergence of a vigorous specialty growing in parallel with fetal medicine, prenatal diagnosis and clinical genetics. Perinatal autopsies are best carried out in tertiary centres which provide these services. Meticulous documentation, flexibility of technique, intelligent use of laboratory tests and wide systematic histopathologic sampling are emphasized. Microbiologic examination is of particular value when carried out by a laboratory having a special interest in genital tract and perinatal pathogens. Karyotyping must be selective if resources are to be conserved and is most productive when there are multiple malformations. Perinatal autopsy is not complete without examination of the placenta and significant lesions should be clearly distinguished from curiosities and from changes secondary to fetal death. The pathologist's wider contribution to perinatal medicine includes providing high quality data to epidemiology units and auditing committees, contributing to the multidisciplinary management of prenatally diagnosed fetal abnormalities, monitoring iatrogenic disease patterns and supporting the process of perinatal grief management. Special problems and diagnostic challenges are to be found when investigating sudden, unexplained intrauterine fetal death, hydrops, bone dysplasias and complicated multiple pregnancies.

Neonatal and post-neonatal onset of early congenital syphilis: a report from Mozambique

Congenital syphilis (CS) has been and continues to be a principal public health problem in developing countries. Despite the wide experience acquired, physicians still have problems in diagnostic evaluation. We report 145 cases of CS at the Central Hospital, Maputo, emphasizing the differences in clinical features and in the results of serological and X-ray examinations between the neonatal and post-neonatal age groups. In the post-neonatal age group, the clinical expression of CS is mostly overt. It is commonly recognized that manifestations of CS in the neonatal age group are often poor or negative, yet a relevant percentage of CS that we report were fully symptomatic. In the neonatal age, the Venereal Disease Research Laboratory (VDRL) test in the mother and characteristic osteochondritic lesions on X-ray examination of the long bones help to make the diagnosis; in the post-neonatal age group, the VDRL test in the child is more often positive than in the mother and X-ray examination shows most periostitic lesions.

Enzyme immunoassay for anti-treponemal IgG: screening or confirmatory test?

AIMS

To review the performance of the Venereal Diseases Research Laboratory (VDRL) test and the Treponema pallidum haemagglutination assay (TPHA) as a combined screen for syphilis to provide a baseline for assessing screening by anti-treponemal IGG EIA.

METHODS

Between 1980 and 1987 all serum samples were screened by both VDRL and TPHA tests. The FTA-ABS test was also used in suspected early primary syphilis, or when one of the other tests was positive. A positive result in a screening test was confirmed by quantitative testing. From 1988 all specimens were screened with an enzyme immunoassay (Captia Syph G) as a single screening test.

RESULTS

Of the 44 primary, 47 secondary, and 38 early latent cases of syphilis, the VDRL and TPHA detected 32 (73%) and 31 (71%) of the primary cases; the combination detected 37 (84%). All 85 cases of cases of secondary and early latent infection were reactive in the TPHA test, whereas the VDRL was reactive in only 68 (80%). EIA had a reported sensitivity of 82% for primary infection.

CONCLUSIONS

EIA can be used as a single screening test for detecting early syphilis because its results are comparable with those of the combined VDRL and TPHA tests. The conventional VDRL test should not be used as a single screening test.