Developmental delay and its predictors among children under five years of age with uncomplicated severe acute malnutrition: a cross-sectional study in rural Pakistan.

BACKGROUND: In developing countries, malnutrition in children and developmental delays are two major challenges for public health. To achieve the vision of the Sustainable Development Goals from the broader perspective of child health, early identification of developmental delays and timely intervention are crucial. The aim of this study is to assess the prevalence of suspected developmental delay and their predictors in children under the age of 5 years with uncomplicated severe acute malnutrition in rural areas of Pakistan. METHODS: A multicentre cross-sectional study was conducted among 185 children with uncomplicated severe acute malnutrition. We screened children aged 6-59 months for their nutritional status and clinical complications. Children fulfilling the inclusion criteria underwent the Denver Development Screening Tool II (DDST-II). The children's global developmental profile was calculated according to the established protocols of DDST-II, which are based on four important domains of development: personal and social behaviour, language, gross motor adaptive skills and fine motor adaptive skills. A pretested questionnaire was used to collect data on socio-demographic and nutritional factors for assessing predictors of developmental delay, which were analysed using a multivariate logistic regression model. RESULTS: Out of 177 children with severe acute malnutrition, 69 (38.9%) had normal global development and 108 (61.1%) had delayed global development. Significant associations were found between global developmental delay and younger children (6-24 months vs. 25-59 months; AOR = 4.53, 95% CI: 1.56-13.10, p < 0.01), children who were not exclusively breastfed (AOR = 3.07, 95% CI: 1.24-7.56, p = 0.01), and a history of contact with a tuberculosis smear-positive adult (AOR = 2.67, 95% CI: 1.30-5.49, p < 0.01). CONCLUSION: About two thirds of the study participants showed delayed or unstable global development. Thus, according to DDST-II-established protocols, there is a high prevalence of suspected developmental delay among children under the age of five years with uncomplicated severe acute malnutrition in rural areas of Pakistan. Children in their first 2 years of life were at particularly high risk due to insufficient breastfeeding. This emphasizes the need to provide adequate infrastructure and information to parents for the prevention of developmental delay in remote areas.

Review: progress in the diagnosis of dengue virus infections and importance of point of care test: a review.

It is an urgent need of highly sensitive, specific and economical diagnostic tools for early and fast diagnosis of highly challenging dengue virus infections. Many laboratory methods including virus detection, genome detection, antigen detection and serological detection of such short-lived viremia were explored but promising outcomes for economical immunochromatographic tests have been reported in this review. With the trend of fast, easy operation, rapid diagnostic tests (RDT) based on immunochromatographic assays are of great importance due to point of care test (POCT) in the dengue endemic regions where it is short of laboratory equipments and cold storage conditions. Such kind of point of care diagnosis is more efficient, fast and user friendly. Moreover, the development of highly advance RDT is dependent on the use of anti-dengue monoclonal antibodies highly specific for particular analyte/antigen.

Development of VHH antibodies against dengue virus type 2 NS1 and comparison with monoclonal antibodies for use in immunological diagnosis.

The possibility of using variable domain heavy-chain antibodies (VHH antibodies) as diagnostic tools for dengue virus (DENV) type 2 NS1 protein was investigated and compared with the use of conventional monoclonal antibodies. After successful expression of DENV type 2 NS1 protein, the genes of VHH antibodies against NS1 protein were biopanned from a non-immune llama library by phage display. VHH antibodies were then expressed and purified from Escherichia coli. Simultaneously, monoclonal antibodies were obtained by the conventional route. Sequence analysis of the VHH antibodies revealed novel and long complementarity determining regions 3 (CDR3). Epitope mapping was performed via a phage display peptide library using purified VHH and monoclonal antibodies as targets. Interestingly, the same region of NS1, which comprises amino acids 224HWPKPHTLW232, was conserved for both kinds of antibodies displaying the consensus motif histidine-tryptophan-tryptophan or tryptophan-proline-tryptophan. The two types of antibodies were used to prepare rapid diagnostic kits based on immunochromatographic assay. The VHH antibody immobilized rapid diagnostic kit showed better sensitivity and specificity than the monoclonal antibody immobilized rapid diagnostic kit, which might be due to the long CDR3 regions of the VHH antibodies and their ability to bind to the pocket and cleft of the targeted antigen. This demonstrates that VHH antibodies are likely to be an option for developing point-of-care tests against DENV infection.