Donghao Yu1, Guangmei Zhang2, Lingyu Gao3, Wenbo Xu4, Bin Cao5. 1. Beijing Chaoyang Hospital of Capital Medical University, Beijing, China; Department of Pulmonary and Critical Care Medicine, Center for Respiratory Diseases, China-Japan Friendship Hospital, National Clinical Research Center for Respiratory Diseases, Beijing, China; Department of Respiratory Medicine, Capital Medical University, Beijing, China. 2. Yucheng People's Hospital, Yucheng City, Shangdong, China. 3. Regional Measles Reference Laboratory for the Western Pacific Region of the World Health Organization and State Key Laboratory for Molecular Virology and Genetic Engineering, National Institute for Viral Disease Control and Prevention, Chinese Centers for Disease Control and Prevention, Beijing, China. 4. Regional Measles Reference Laboratory for the Western Pacific Region of the World Health Organization and State Key Laboratory for Molecular Virology and Genetic Engineering, National Institute for Viral Disease Control and Prevention, Chinese Centers for Disease Control and Prevention, Beijing, China. Electronic address: wenbo_xu1@aliyun.com. 5. Beijing Chaoyang Hospital of Capital Medical University, Beijing, China; Department of Pulmonary and Critical Care Medicine, Center for Respiratory Diseases, China-Japan Friendship Hospital, National Clinical Research Center for Respiratory Diseases, Beijing, China; Department of Respiratory Medicine, Capital Medical University, Beijing, China. Electronic address: caobin_ben@163.com.
Abstract
BACKGROUND: Vaccinated individuals infected with measles can develop nodular pneumonia. These cases can be misdiagnosed due to the absence of specific IgM and typical symptoms. An effective diagnostic tool is needed. METHODS: During March 2016, adult inpatients in Yucheng People's Hospital were enrolled prospectively and included in the study. Patients were included if samples were obtained ≤14 days from the onset of fever. Measles virus was detected by RT-PCR of the oropharyngeal swab sample. Chest computed tomography scans and medical records were obtained. Oropharyngeal swabs and blood samples were collected for IgM and IgG testing, RT-PCR, and gene sequencing. RESULTS: Sixteen patients were enrolled. Ten were found to have nodular pneumonia and were defined as the nodular group. The remaining six patients were defined as the control group. Measles-specific IgG titers in the nodular group were high (3618.3-5000mIU/ml), while IgM titers were low (<25mIU/ml); IgG titers in the control group were low (241.4-2560.3mIU/ml), while IgM titers were high (137-5000mIU/ml). No obvious viral mutation was detected in the nodular group. CONCLUSIONS: Measles-associated nodular pneumonia was only evident in those patients with an IgG/IgM ratio >20. In measles outbreaks, the IgG/IgM ratio may be useful to identify nodular pneumonia.
BACKGROUND: Vaccinated individuals infected with measles can develop nodular pneumonia. These cases can be misdiagnosed due to the absence of specific IgM and typical symptoms. An effective diagnostic tool is needed. METHODS: During March 2016, adult inpatients in Yucheng People's Hospital were enrolled prospectively and included in the study. Patients were included if samples were obtained ≤14 days from the onset of fever. Measles virus was detected by RT-PCR of the oropharyngeal swab sample. Chest computed tomography scans and medical records were obtained. Oropharyngeal swabs and blood samples were collected for IgM and IgG testing, RT-PCR, and gene sequencing. RESULTS: Sixteen patients were enrolled. Ten were found to have nodular pneumonia and were defined as the nodular group. The remaining six patients were defined as the control group. Measles-specific IgG titers in the nodular group were high (3618.3-5000mIU/ml), while IgM titers were low (<25mIU/ml); IgG titers in the control group were low (241.4-2560.3mIU/ml), while IgM titers were high (137-5000mIU/ml). No obvious viral mutation was detected in the nodular group. CONCLUSIONS: Measles-associated nodular pneumonia was only evident in those patients with an IgG/IgM ratio >20. In measles outbreaks, the IgG/IgM ratio may be useful to identify nodular pneumonia.