The Hong Kong Centre for Health Protection (CHP) reported recently on a domestic cluster of measles. The cluster affected  a 10-month old boy and his 42-year-old father, who resided in Futian, Shenzhen.

Hong Kong/CIA
Hong Kong/CIA

The boy presented with fever, cough, runny nose and conjunctivitis on May 17 and rash on May 21. He came to Hong Kong on May 21 and was admitted to a private hospital from May 21 to May 25. His throat swab was tested positive for measles virus RNA. Contact tracing revealed his 42-year-old father had fever and cough on May 4 and rash on May 11. He had also been admitted to the same private hospital from May 11 to May 15 and was initially managed as infectious mononucleosis. His blood specimen subsequently taken on May 21 was tested positive for immunoglobulin M (IgM) against measles virus. Both father and son were stable all along.

Epidemiological investigation revealed that the boy had stayed in Shenzhen during the whole incubation period before he came to Hong Kong for treatment. His father travelled to Hong Kong for work on weekdays and stayed in Shenzhen after work and during weekends. The boy was born in Hong Kong and was not yet due for the first dose of Measles, Mumps and Rubella (MMR) vaccine according to the Hong Kong Childhood Immunisation Programme (HKCIP). His father who was also born in Hong Kong could not recall his vaccination history.

The boy’s 33-year-old mother had fever, cough and sore throat on May 22. She did not have rash and her blood specimen taken on May 22 was tested negative for IgM and positive for IgG against measles virus. She was managed as acute pharyngitis and had recovered.The boy’s three-year-old sister remained asymptomatic and she had received the first dose of MMR according to the HKCIP. Contact tracing did not identify further cases.