Outbreak of severe acute respiratory infection in Southern Province, Sri Lanka in 2018: a cross-sectional study.

OBJECTIVES: To determine aetiology of illness among children and adults presenting during outbreak of severe respiratory illness in Southern Province, Sri Lanka, in 2018. DESIGN: Prospective, cross-sectional study. SETTING: 1600-bed, public, tertiary care hospital in Southern Province, Sri Lanka. PARTICIPANTS: 410 consecutive patients, including 371 children and 39 adults, who were admitted with suspected viral pneumonia (passive surveillance) or who met case definition for acute respiratory illness (active surveillance) in May to June 2018. RESULTS: We found that cocirculation of influenza A (22.6% of cases), respiratory syncytial virus (27.8%) and adenovirus (AdV) (30.7%; type B3) was responsible for the outbreak. Mortality was noted in 4.5% of paediatric cases identified during active surveillance. Virus type and viral coinfection were not significantly associated with mortality. CONCLUSIONS: This is the first report of intense cocirculation of multiple respiratory viruses as a cause of an outbreak of severe acute respiratory illness in Sri Lanka, and the first time that AdV has been documented as a cause of a respiratory outbreak in the country. Our results emphasise the need for continued vigilance in surveying for known and emerging respiratory viruses in the tropics.

Subacute sclerosing panencephalitis: a rare cause of acute cortical visual impairment in an adult.

Adult onset subacute sclerosing panencephalitis (SSPE) after the third decade of life is rare and the manifestations can mimic disorders such as dysmyelinating and metabolic disorders. This case report presents a patient with acute binocular visual impairment in his fifth decade as the first manifestation of SSPE. This is preventable with immunisation against measles. A prior history of measles infection may not be forthcoming in adult onset SSPE. This should be kept in mind as a differential diagnosis when a patient from endemic area presents with acute visual loss even in the absence of classic features. Periodic generalised discharges on the EEG without myoclonus may be seen in this condition rarely as in this case.

Susceptibility for varicella and factors associated with immunity among pregnant women in a tertiary care hospital in Sri Lanka- a cross-sectional study.

BACKGROUND: Varicella during pregnancy can lead to serious maternal and fetal consequences. Although an effective vaccine is available it is not incorporated in to the routine vaccination programs in most of the Asian countries. Objectives of the study were to determine the susceptibility to varicella and factors associated with immunity, among a group of pregnant women attending to a tertiary care hospital in Sri Lanka. METHODS: A hospital based descriptive cross sectional study was carried out at De Soyza maternity Hospital, Colombo. A sample of 385 pregnant women was selected. Data were collected through an interviewer administered questionnaire; presence of varicella IgG in blood was assessed by a validated commercial ELISA (Enzyme Linked Immunosorbant Assay. RESULTS: The sample had a mean age of 28.5 years and majority was educated beyond General Certificate of Education (GCE) Ordinary Level. We found that 34% of study population was susceptible for the infection. A past history of varicella had a 89.5% positive predictive value and 53.1% negative predictive value for varicella immunity. Varicella sero-positivity was only associated with a lower educational level and number of childhood household members more than four. There was no association of sero-positivity with age. CONCLUSION: This study demonstrates that a significant proportion of pregnant women of the study population are varicella-susceptible. Pre-pregnancy screening and preventive strategies including vaccination should be evaluated. History of past varicella infection could be a useful screening tool to exclude patients for vaccination.

The reliability of HBV core antibody in serological screening for hepatitis B virus.

INTRODUCTION: Accurate diagnosis of hepatitis B virus (HBV) infection is essential for infection control, treatment and screening of potential blood, organ and tissue donors. We assessed the sensitivity of the HBsAg and HBcAb as screening assays alone and in combination for detecting HBV infection in a series of Australian patients. The performance of the Architect (Abbott Diagnostics, Germany) and the Elecsys (Roche Diagnostics, Germany) platforms were assessed for detection of HBcAb. METHODS: There were 2778 blood samples assessed using the COBAS Ampliprep/TaqMan test for HBV DNA, of which 331 sera had concurrent HBV serology testing. This allowed determination of the correlation between HBV DNA and different serological markers. Of the 331 sera, 260 had sufficient residual volume to be retested for HBcAb using both Elecsys and the Architect assays. RESULTS: Of the 331 patients, one (0.3%) was negative by the Architect Anti-HBc II assay, in the presence of HBV DNA and positive HBsAg, consistent with recent infection. Positive HBcAb in the absence of HBV DNA was found in 67 of 331 (20.2%) patients. Of these, 18 of 67 had isolated HBcAb with negative results on all other tests, with 12 of 18 (3.6%) demonstrating low HBcAb signals on chemiluminscent microparticle assay. No cases of detectable HBV DNA in the presence of negative serology were found. When the HBcAb was used as a marker for past exposure or chronic HBV infection, the Architect Anti-HBc II assay demonstrated sensitivity and specificity of 98% and 79.9%, respectively, compared to 90% and 78.9%, respectively, for the Elecsys Anti-HBc assay. The combination of the Architect Anti-HBc II and HBsAg assays, as per conventional solid organ donor and recipient screening protocols, had 90% specificity and 100% sensitivity for determining HBV infection. CONCLUSION: This study shows that the use of combined HBsAg and HBcAb is sensitive and reliable for screening and predicting HBV nucleic acid test (NAT) positivity, whereas HBcAb alone missed an acute infection in this study population. There were no significant differences detectable between the Architect and the Elecsys HBcAb assays (p=0.001), suggesting laboratories should assess individual assays in the local population before use as screening tests.

Laboratory diagnosis, molecular characteristics, epidemiological and clinical features of an outbreak of measles in a low incidence population in Australia.

BACKGROUND: Prompt and accurate laboratory diagnosis of measles is essential for case detection, outbreak management and ongoing surveillance in low incidence countries. Several disease markers are employed for diagnosis and are important to determine epidemiological and molecular characteristics for future control measures. OBJECTIVES: To report different disease markers, genotypes and epidemiology of a measles outbreak in Australia, a low incidence country. STUDY DESIGN: A retrospective descriptive study of the clinical and epidemiological features and laboratory diagnosis in 16 confirmed measles cases using measles serum IgM/IgG, antigen detection (IFA), viral RNA detection by real-time PCR and genotyping results for respiratory and urine specimens processed in one reference laboratory. RESULTS: Of the 16 confirmed measles cases, 11 were young adults aged between 20-35 years and 15 were not age-appropriately vaccinated. The most common genotype detected was D9 (11/16), followed by D4 (1/16) and D8 (1/16). Two imported cases were from the Philippines (D4) and Italy (D9). Of six disease markers, respiratory swab PCR and serum IgM gave the highest percentage (100%) of positive samples for confirmed cases followed by urine PCR (90.9%), serum PCR (66.6%), urine IFA (54.5%) and respiratory IFA (46.2%). CONCLUSIONS: Measles should be considered in the differential diagnosis of a presentation with fever and rash, even in countries in the elimination phase of measles control. Genotyping is a powerful molecular-epidemiological tool to assist low incidence countries towards eradication goals. Improving vaccination coverage remains essential, particularly in young adults and travellers.