Protective immunity against hepatitis B virus infection in a group of vaccinated Sri Lankan military service men following a complete course of vaccination.

Vaccination is the appropriate measure to protect military personnel against the hepatitis B virus (HBV) infection. Testing the military personnel for anti-HBs levels after vaccination is vital in re-vaccinating those that have not developed protective immunity. The aim of the current study was to determine the immunity in a group of vaccinated Sri Lankan military personnel (n = 150; age = 26-44 years) following a complete course of hepatitis B virus surface antigen (HBsAg) vaccination by assessing the antibodies against HBsAg (anti-HBs) levels. Three months after the last dose of the vaccination, blood samples were collected from the study population and tested for anti-HBs levels using a commercially available ELISA. Of the 150 military service men tested, 139 (92.67%) had anti-HBs levels higher than 10 mIU/mL, WHO approved levels for protective immunity against HBV infection. Of the 139 that had sufficient anti-HBs levels, 24% (36/150) had anti-HBs levels between 10 and 100 mIU/mL and 68.67% (103/150) had anti-HBs levels > 100 mIU/mL. Overall, 7.33% (11/150) participants had anti-HBs levels < 10 mIU/mL. Sero-conversion to > 10 mIU/mL anti-HBs was more than 90% in those that were less than 40 years of age and it was less than 90% in those that were more than 40 years of age.

A mini outbreak of human metapneumovirus infection with severe acute respiratory symptoms in a selected group of children presented to a teaching hospital in Sri Lanka.

Human metapneumovirus (hMPV) of the family Paramyxoviridae is a relatively new virus causing severe acute respiratory tract infections (SARI) in children. Data on hMPV infection in Asia including Sri Lanka is limited. We aimed to detect respiratory viruses including hMPV in a selected group of children affected by a small outbreak of SARI presented to the Teaching Hospital, Peradeniya (THP), Sri Lanka in 2014. Nasopharyngeal aspirates (NPA) were obtained from 21 children with SARI and tested for hMPV, influenza A and B, parainfluenza 1, 2 and 3 (PIV 1-3), adenovirus and respiratory syncytial virus (RSV) antigens using an immunofluorescence assay (IFA). In addition, a one step RT-PCR was done for the detection of hMPV from the viral RNA extracts. Of the 21 NPA samples tested for respiratory viral antigens by IFA, two were positive for RSV (9.5%), one was positive for influenza A (4.8%) and one was positive for both adenovirus and PIV-2 (4.8%). Of the 21 NPA viral RNA extracts tested by RT-PCR, 18 (86%) were positive for hMPV, in which 2 were co-infected with RSV and influenza A virus, respectively. hMPV was the predominant cause of SARI outbreak (2014) in children presented to the THP, Sri Lanka.