Early Detection of Diagnostic Markers Of Measles For Better Management And Control Of Infection

Measles is a highly infectious and contagious viral disease which affects the respiratory system caused by a single-stranded, enveloped RNA paramyxovirus of the genus Morbillivirus. Measles is an endemic disease in many countries of the world including Pakistan, mostly affecting children under 14 years of age. Measles is a droplet infection so the disease is spread to others through contact with fluids from an infected person s nose and mouth, either directly or through aerosol transmission. Overcrowding and improper ventilation are major predisposing factors in its spread, 90% of people without immunity sharing a house with an infected person will catch it. The classical symptoms of measles include four day fevers, the three Cs—cough, coryza (runny nose) and conjunctivitis (red eyes). The fever may reach up to 40C (1040F). Koplik s spots seen inside the mouth are diagnostic, they are transient and may disappear within a day of arising. The characteristic measles rash is classically described as a generalized, maculopapular, erythematous rash that begins several days after the fever starts. It starts on the head before spreading to cover most of the body, often causing itching. The rash is said to stain , changing colour from red to dark brown, before disappearing. The consequences of infection with measles virus are recovery, chronicity or death. Although most patients survive, but approximately 15 percent of patients experience complications, mild, or severe such as subacute sclerosing panencephalitis (SSPE) which is fatal. Laboratory diagnosis of measles can be done with confirmation of positive measles IgM antibodies, or detection of Measles virus RNA by PCR from respiratory specimens. Fortunately the vaccine against measles is available and is included in the EPI (expanded program of immunization. This study was designed to know the best laboratory diagnostic test for early diagnosis of measles virus infection to facilitate better management of disease and prevention of its complications like Pneumonia and fever and typical symptoms of measles (running nose, conjunctivitis and rashes), between the age of 2-12 years, visiting Pediatric units of Civil Hospital, Karachi, were included in this study. Demographic data including age, gender, socioeconomic status, especially vaccination against measles and duration of fever were recorded. A total of 106 clinically diagnosed cases of measles were included. Out of 106 blood samples of patients , 48 (45.3%) children exhibited measles specific IgM antibodies . Among measles positive children, 18 children had received measles vaccination. Among the vaccinated group of 18 children, only 6 (33.3%) were positive for measles IgM, while among the unvaccinated group 42(47.7%) tested positive for measles specific IgM, All measles specific IgM positive children (N=48) had history of fever for three days and more while others had fever of less than three days. Females (52%) were affected slightly more than males .Measles virus RNA was detected in all 106 samples of nasal secretions. Genotype analysis indicated Measles virus genotype B2 as the most prominent causative strain. In conclusion we can say that Anti-Measles IgM test can be used for early diagnosis of measles after three days of onset of fever for better management , negative test does not exclude measles. Measles virus RNA can be detected in nasal secretion irrespective of duration of fever. Measles infection in vaccinated children reflects on the efficacy of vaccines in Pakistan. The poor quality of routine vaccination program plus lack of proper surveillance system are some of the factors responsible for the rise in measles cases in Pakistan.