Epidemiology of acute respiratory viral infections in children in Vientiane, Lao People's Democratic Republic.

Respiratory infections are one of the most frequent reasons for medical consultations in children. In low resource settings such as in Lao People's Democratic Republic, knowledge gaps and the dearth of laboratory capacity to support differential diagnosis may contribute to antibiotic overuse. We studied the etiology, temporal trends, and genetic diversity of viral respiratory infections in children to provide evidence for prevention and treatment guidelines. From September 2014 to October 2015, throat swabs and nasopharyngeal aspirates from 445 children under 10 years old with symptoms of acute respiratory infection were collected at the Children Hospital in Vientiane. Rapid antigen tests were performed for influenza A and B and respiratory syncytial virus. Real-time reverse-transcription polymerase chain reactions (RT-PCRs) were performed to detect 16 viruses. Influenza infections were detected with a higher sensitivity using PCR than with the rapid antigen test. By RT-PCR screening, at least one pathogen could be identified for 71.7% of cases. Human rhinoviruses were most frequently detected (29.9%), followed by influenza A and B viruses combined (15.9%). We identify and discuss the seasonality of some of the infections. Altogether these data provide a detailed characterization of respiratory pathogens in Lao children and we provide recommendations for vaccination and further studies.

Seroprotection at Different Levels of the Healthcare System After Routine Vaccination With Diphtheria-Tetanus-Pertussis whole cell-Hepatitis B-Haemophilus influenzae Type B in Lao People's Democratic Republic.

BACKGROUND: The Lao People's Democratic Republic continues to sustain a considerable burden of vaccine-preventable diseases because of incomplete vaccine coverage and weak vaccine responses. We have assessed seroconversion after routine vaccination with the pentavalent vaccine to capture weaknesses of vaccine management at the different levels of the healthcare system. METHODS: A total of 1151 children (aged 8-28 months) with 3 documented doses of the pentavalent vaccine delivered at central hospitals in Vientiane and the provincial hospital, 3 district hospitals, and 10 health centers in Bolikhamxay province were enrolled. Sociodemographic information was collected with a standardized questionnaire. Serum samples were analyzed for antibodies against vaccine components, and bivariate and multivariable analyses were performed to identify risk factors for low vaccine responses. RESULTS: Seroprotection rates at the provincial, district, and health center level were as high as in central hospitals, but seroprotection rates in areas covered by remote health centers were significantly lower. Protective levels also rapidly decreased with age at sampling. Seroprotection rates in Bolikhamxay against the different components reached 70%-77% and were up to 20% higher than in previous studies in the same region; 18.8% more children received the hepatitis B vaccine birth dose and the hepatitis B virus infection rate was 4 times lower. CONCLUSIONS: Vaccine immunogenicity has dramatically improved in a central province, likely due to training and investment in the cold chain. Nevertheless, there remains a need to focus on the "last mile" in remote areas were most children are vaccinated through outreach activities.

Varicella zoster and fever rash surveillance in Lao People's Democratic Republic.

BACKGROUND: In Lao PDR, the epidemiology of varicella infection is uncertain, since it is not a notifiable disease and VZV outbreaks are rarely reported as fever/rash (F/R) diseases. METHODS: We estimated the seroprevalence of VZV (IgG ELISA) in different age cohorts (9 months to 46 years; N = 3139) and investigated VZV and 6 other viruses in patients during F/R outbreaks and in an ad hoc sentinel site in the context of the national reporting system (IgM ELISA, PCR). RESULTS: At least 80% of the sampled population had evidence of VZV infection before the age of 15. The largest increase in seroprevalence occurred between the age groups 1 to 5 and 6 to 7 year-olds. A VZV outbreak (clade 2) also occurred in this age group mostly during the first year of primary school (median age 6 years, interquartile range 4.0-7.5). During a dengue outbreak, 6% had varicella. At our F/R sentinel site, 14% of children with viral etiology were laboratory diagnosed as varicella and among others, a sizeable number of measles (N = 12) and rubella cases (N = 25) was detected compared to those reported for the whole country (N = 56 and 45), highlighting nationwide a large challenge of underreporting or misdiagnosis of these notifiable diseases because of lack of diagnostic laboratory capacity. CONCLUSION: We recommend strengthening the clinical and laboratory diagnosis of VZV, measles and rubella, the surveillance and reporting of notifiable F/R diseases by retraining of healthcare workers and by setting up sentinel sites and enhancing laboratory capacity.

Congenital heart disease at Laos Children's Hospital: Two year experience.

BACKGROUND: Management of congenital heart disease (CHD) in developing countries is challenging because of limited access to health-care facilities and socioeconomic limitations. The aim of this study was to describe the recent experience with CHD at Children's Hospital, Vientiane, Laos, the only pediatric referral hospital in the country. METHODS: From July 2013 to November 2015, 1009 echocardiograms were carried out in 797 individuals who visited Children's Hospital, in whom CHD was identified in 213. Demographic characteristics, echocardiography and age at first CHD diagnosis on echocardiogram were compared by residential area. RESULTS: Among the 213 patients, the most frequent anomalies, in descending order, were ventricular septal defect, atrial septal defect, patent ductus arteriosus, and tetralogy of Fallot. Moderate or severe CHD requiring surgery or intervention was detected in 137 patients; median age at initial diagnosis was 6.0 months (IQR, 1.5-29.8). Among those with moderate or severe CHD, 89 patients were from rural areas and 48 from the capital area. The proportion of patients from rural areas older than 1 and 3 years at diagnosis was 46.1% and 32.6%, respectively. In contrast, patients from the capital area were diagnosed at a significantly earlier age: 16.7% at age >1 year and 6.2% at age >3 years (both P < 0.001 vs rural areas). CONCLUSIONS: Diagnosis of CHD requiring surgery is delayed in Laos, especially in rural areas. Better education and training of local medical staff, and greater access to medical advice are required to improve CHD care in Laos.

Hepatitis B virus and other transfusion-transmissible infections in child blood recipients in Lao People's Democratic Republic: a hospital-based study.

INTRODUCTION: Children requiring multiple blood transfusions are at high risk of transfusion-transmissible infections (TTIs). Lao People's Democratic Republic is a low-resource setting where donor blood screening faces challenges. This study aimed to determine the burden of TTIs in children in Vientiane Capital. METHODS: 300 children with transfusion history and 300 controls were recruited. In addition, 49 newly diagnosed transfusion recipients were followed for up to 12 months. Serum was tested for hepatitis B surface antigen and IgG antibodies against parvovirus B19, hepatitis B, C and E viruses. RESULTS: The patients had a similar prevalence of anti-hepatitis B core antibodies (56; 18.7%) and hepatitis B surface antigen (8; 2.7%) as the controls (58; 19.3% and 9; 3.0%, respectively). However, there was a higher prevalence of an antibody profile suggestive of hepatitis B vaccination (anti-hepatitis B surface antibody positive/anti-hepatitis B core antibody negative) in the transfused group (140/299; 46.8%) than in controls (77/300; 25.7%, p<0.01). All other markers were similar in the patients and controls or higher in the controls: anti-hepatitis C virus (2.7% and 3.3%, p=0.6), anti-hepatitis E virus (7.5% and 12.7%, p=0.006) and anti-parvovirus B19 (2.4% and 8.5%, p=0.001). The longitudinal cohort did not show an increase in any marker over time. CONCLUSION: Our results suggest no significant role of TTIs in Lao children. The higher prevalence of the hepatitis B vaccination profile in transfusion recipients showed that recommendations to vaccinate before commencing transfusions is at least partially implemented, although there is room for improvement.

Correction: Patch test results in paediatric patients with atopic dermatitis in Laos.

[This corrects the article DOI: 10.1371/journal.pone.0231455.].

Patch test results in paediatric patients with atopic dermatitis in Laos.

BACKGROUND: Dermatological services in Laos, South East Asia are limited mainly to the capital and patch testing is currently not available, so no data exists regarding the common cutaneous allergens in this population. OBJECTIVES: The aim of this study was to document common allergens in paediatric patients with atopic dermatitis attending the allergy clinic in the capital, Vientiane. PATIENTS/MATERIALS/METHODS: Fifty paediatric patients with atopic dermatitis were patch tested using TRUE Test® panels 1 to 3 (35 allergens). Readings were taken at Days 2 and 4. RESULTS: Twenty-six positive patch tests were recorded on Day 4 in 15 children (30%). The most common allergens were: gold (18%), nickel (10%), formaldehyde (6%) and p-Phenylenediamine (6%). Other positive allergens were potassium dichromate (2%), cobalt dichloride (2%), Bronopol (2%), paraben mix (2%), fragrance mix 1 (2%) and neomycin (2%). The majority of the patients with positive reactions were female. CONCLUSIONS: This study represents the first documented patch test results in the Lao population. It is hoped that these findings will help clinicians to advise the families of children with atopic dermatitis on common allergens to avoid and inform future work on contact dermatitis in this population.

Timeliness of immunisation with the pentavalent vaccine at different levels of the health care system in the Lao People's Democratic Republic: A cross-sectional study.

BACKGROUND: The timely administration of vaccines is considered to be important for both individual and herd immunity. In this study, we investigated the timeliness of the diphtheria-tetanus-whole cell pertussis-hepatitis B-Haemophilus influenzae type b (pentavalent) vaccine, scheduled at 6, 10 and 14 weeks of age in the Lao People's Democratic Republic. We also investigated factors associated with delayed immunization. METHODS: 1162 children aged 8-28 months who had received the full course of the pentavalent vaccine at different levels of the health care system were enrolled. Vaccination dates documented in hospital records and/or immunisation cards were recorded. Age at vaccination and time intervals between doses were calculated. Predictors for timely completion with the pentavalent vaccine at 24 weeks were assessed by bivariate and multivariable analyses. RESULTS: Several discrepancies in dates between vaccination documents were observed. In general, vaccination with the pentavalent vaccine was found to be delayed, especially in health care settings below the provincial hospital level. Compared to the central hospital level, less participants who were vaccinated at the district/health center level received the third dose by 16 (48% at the central hospital level vs. 7.1% at the district and 12.4% at the health center level) and 24 weeks of age (94.4% at the central hospital level vs 64.6% at the district-outreach and 57.4% at the health center level) respectively. In logistic regression analyses, lower education level of the mother as well as vaccination by outreach service, were independently associated with delayed completion of vaccination. CONCLUSION: We observed a general delay of vaccination, especially at lower ranked facilities, which correlated with indicators of poor access to health services. This highlights the need for further improving health equity in rural areas. Age-appropriate vaccination should become a quality indicator for the national immunization programme. In addition, we recommend further training of the health care staff regarding the importance of reliable documentation of dates.

Pertussis in Lao PDR: Seroprevalence and disease.

OBJECTIVES: Pertussis is a debilitating vaccine-preventable infection. The aim of this study was to determine susceptibility and exposure to pertussis in Lao PDR in different age groups and subpopulations. METHODS: A total 3072 serum samples were obtained from different cohorts: children with documented vaccination, pre-schoolers, schoolchildren, blood donors, healthcare workers (HCWs), and pregnant women and paired cord blood. Samples were tested for anti-pertussis toxin IgG antibodies. A history of Bordetella pertussis exposure was defined according to antibody titres. Four hundred and seventy-five throat swabs and nasopharyngeal aspirates were analysed by PCR for the presence of B. pertussis in symptomatic children at the Children's Hospital in Vientiane. RESULTS: Overall pertussis seroprevalence was 57.5%. The prevalence of titres indicating acute infection or recent vaccination or infection/vaccination within the last 12 months ranged from 7.4% (100/1356) in adults to 21.4% (25/117) in pre-schoolers (age 1-5 years). B. pertussis was detected in 1.05% (5/475) of children with respiratory symptoms in Vientiane Capital. CONCLUSIONS: It is suggested that routine childhood vaccination, in particular outreach, as well as vaccination of HCWs should be strengthened. A childhood booster and vaccination of pregnant mothers should be considered. There is also a need to improve reporting and to introduce pertussis testing in at least one central facility.

The first picture archiving and communication system in Lao People's Democratic Republic: Changes in the utilization rate of imaging tests in the first year after implementation.

BACKGROUND: Implementation of the Picture Archiving and Communication System (PACS) is more challenging in developing countries than in developed countries. Given that the first PACS in Lao People's Democratic Republic (PDR) was successfully installed at the Children's Hospital of Lao PDR, we aimed to investigate whether the utilization rate of imaging tests increased after PACS implementation. METHODS: PACS was implemented at the Children's Hospital of Lao PDR in December 2014. We compared the utilization rates of imaging tests including X-ray and ultrasound examinations between the pre-PACS period (from December 2013 to November 2014) and the post-PACS period (from December 2014 to November 2015). The utilization rate was defined as the number of imaging tests divided by the number of patients per month. RESULTS: The average number of total imaging tests was 225.8/month (standard deviation [SD], 37.7) during the 1-year pre-PACS period and was 269.4/month (SD, 38.5) during the 1-year post-PACS period (P=0.0103). The utilization rate of total imaging tests significantly increased after PACS implementation (pre-PACS, 2.47%/month; post-PACS, 4.23%/month; P<0.0001). Increased utilization rates were observed for both X-rays (pre-PACS, 1.65%/month; post-PACS, 2.38%/month; P=0.0004) and ultrasound examinations (pre-PACS, 0.82%/month; post-PACS, 1.85%/month; P=0.0001). CONCLUSIONS: The implementation of PACS at the Children's Hospital of Lao PDR resulted in a significant increase in the utilization rate of imaging tests, suggesting the indirect benefit of improved quality of care. Our findings showed that the benefits of PACS can be realized even in a resource-limited country such as Lao PDR.