Timeliness and Out-of-Sequence Vaccination among Young Children in Burkina Faso – Analysis of Health and Demographic Surveillance System (HDSS) Data.

Aims: The aim of this study is to investigate the timeliness and out-of-sequence vaccination among children aged less than five years through the data of a local Health and Demographic Surveillance System (HDSS) in Burkina Faso. Study Design: Cross-sectional study nested into an existing HDSS. Place and Duration of Study: Nouna Health District in north-western Burkina Faso, over the period of September 2008 to December 2009. Methodology: We used data of 7,644 children born between September 2003 and March 2009. Vaccination data were provided on the basis of events recorded on vaccination cards. We assessed vaccination timeliness and the frequency of out-of-sequence vaccination. Results: The highest rates of timely administration were observed with vaccines recommended at birth (e.g. 68% for BCG) while the lowest rates were observed with vaccines given in late infancy (e.g. 33% for measles). The frequency of out-of-sequence vaccination between BCG and DTP/Penta 1 or between DTP/Penta 3 and measles were respectively around 5% and 4%. Out-of-sequence vaccination in early infancy occurred significantly more frequent in rural compared to urban areas contrary to out-of-sequence vaccination in late infancy. Both, timely and correct sequencing of vaccination have significantly improved in recent years in the study area. Conclusions: This study supports that significant vaccination delay occurs in SSA communities with high vaccination coverage and that the frequency of out-of-sequence vaccinations varies substantially between countries.

The epidemiology of malaria in the Papua New Guinea highlands: 7. Southern Highlands Province

As the last part of a program to survey the extent of malaria transmission in the Papua New Guinea highlands, a series of rapid malaria surveys were conducted in 2003-2004 and 2005 in different parts of Southern Highlands Province. Malaria was found to be highly endemic in Lake Kutubu (prevalence rate (PR): 17-33%), moderate to highly endemic in Erave (PR: 10-31%) and moderately endemic in low-lying parts (< 1500 m) of Poroma and Kagua (PR: 12-17%), but was rare or absent elsewhere. A reported malaria epidemic prior to the 2004 surveys could be confirmed for the Poroma (PR: 26%) but not for the lower Kagua area. In Kutubu/Erave Plasmodium falciparum was the most common cause of infection (42%), followed by P. vivax (39%) and P. malariae (16%). In other areas most infections were due to P. vivax (63%). Most infections were of low density (72% < 500/ microl) and not associated with febrile illness. Overall, malaria was only a significant source of febrile illness when prevalence rates rose above 10%, or in epidemics. However, concurrent parasitaemia led to a significant reduction in haemoglobin (Hb) level (1.2 g/dl, CI95: [1.1-1.4.], p < 0.001) and population mean Hb levels were strongly correlated with overall prevalence of malarial infections (r = -0.79, p < 0.001). Based on the survey results, areas of different malaria epidemiology are delineated and options for control in each area are discussed.

A non-invasive assessment of hepatitis B virus carrier status using saliva samples.

A non-invasive testing method to determine hepatitis B virus (HBV) carrier status in pregnant women was evaluated. Paired serum and saliva samples were collected and assessment of hepatitis B markers were performed. Of the 502 women enrolled, 5.6% (28/502) of their sera were found to be positive for HBV surface antigen (HBsAg). Assessment of 28 HBsAg seroreactive and 200 HBsAg sero-non-reactive paired saliva samples showed that 17 saliva contained HBsAg. Fourteen of the saliva reactive samples were matched to the serum reactive samples (50% sensitivity); and 3 saliva samples were positive for HBsAg among 200 subjects seronegative for HBsAg (98.5% specificity). Seven of the 28 HBsAg positive sera were found to be reactive for HBV envelope antigen (HBeAg) (25%). One of seven HBeAg seroreactive and 16 HBeAg seronegative paired saliva samples tested were non-reactive for HBeAg. This report found a non-invasive saliva testing method to be a possible alternative approach for determining chronic HBV carrier status if the sensitivity of the test can be improved.

Use of Indonesian non-human primate erythrocytes for measles hemagglutination inhibition serology.

The use of erythrocytes (RBC) from Presbytis cristata, P. melalophus and Macaca fascicularis for measles hemagglutination inhibition serologies is presented. These primates can provide a ready supply of RBC for diagnostic reagent use in areas of the world where the African green monkey or rhesus macaque are not available. Individuals of each species are useful but must be screened for hemagglutination ability of their erythrocytes. The animal can then be chosen that has erythrocytes which best agglutinate with the antigen being used.