Laboratory diagnosis of acute measles infections in hospitalized children in Zambia

Abstract

SummaryLaboratory diagnosis of measles infection is rarely performed in developing countries and tends to depend on clinical symptoms alone. We evaluated detection of immunoglobulin M (IgM) antibodies for confirmation of acute measles infection in Zambia. In 149 hospitalized children with clinical diagnosis of measles, IgM antibodies were detected in 88.6% (132/149). The IgM-positive rate increased with time after onset of skin rash and all samples were positive after 4 days. In addition to IgM antibody test, virus isolations from throat swabs using B95a cells were also performed. These were positive in only 20.9% (14/67), and both IgM and virus isolation in combination increased the positive rate to 92.5% (62/67). Vaccinated children had higher neutralizing (Nt) antibody responses and, among IgM-negative patients, all 4 vaccinated children had high Nt antibodies while all 10 unvaccinated children had negative or low Nt results. The IgM antibody test was proved to be a sensitive method for laboratory confirmation of measles virus infection in developing countries.

Measles in suburban Khartoum: an epidemiological and clinical study

“…The WHO standard clinical cases definition was designed for maximum sensitivity at the expense of specificity for surveillance purposes and led to a correct diagnosis in 75% of measles cases in our field study population. Reports from other areas vary: in Zambia, a higher sensitivity of 86% (increasing to 100% after 4 days) was found among hospitalized children, who may have been more ill and therefore more likely to have measles than another viral illness which on average, as also observed in this study, runs a milder course (Oshitani et al . 1997).…”

“…The WHO standard clinical cases definition was designed for maximum sensitivity at the expense of specificity for surveillance purposes and led to a correct diagnosis in 75% of measles cases in our field study population. Reports from other areas vary: in Zambia, a higher sensitivity of 86% (increasing to 100% after 4 days) was found among hospitalized children, who may have been more ill and therefore more likely to have measles than another viral illness which on average, as also observed in this study, runs a milder course (Oshitani et al 1997). An Australian study used notification to a public health unit as the entry criterion and found only 49% sensitivity using the slightly different CDC classification, which is identical to the WHO definition apart from requiring the fever to be >38.3°C and the rash to be present for at least 3 days (CDC 1990;Ferson et al 1995).…”

Combination of Reverse Transcriptase PCR Analysis and Immunoglobulin M Detection on Filter Paper Blood Samples Allows Diagnostic and Epidemiological Studies of Measles

“…In a cohort study of almost 200 clinically diagnosed Sudanese measles patients, we recently found that in approximately 25% of these cases the clinical symptoms were not related to acute MV infection (6). Other studies reported between 12% and more than 50% falsely diagnosed measles cases (5,7,11,13,14), with an apparent inverse relationship with vaccination coverage.…”

High CD4/CD45RO+ and CD8/CD45RO+ frequencies in children with vaccine‐modified measles

“…Despite the high coverage with measles vaccine in most parts of Africa, epidemics of measles still occur with reduced severity in an increasing proportion of older children previously immunized 17,20–22 . In general, the prodromal period in VMM is shorter.…”