The optical properties of indocyanine green (ICG) as a near-infrared (NIR) fluorescence dye depend on the nature of the solvent medium and the dye concentration. In the ICG absorption spectra of water, at high concentrations, there were absorption maxima at 700 nm, implying H-aggregates. With ICG dilution, the main absorption peak was at 780 nm, implying monomers. However, in ethanol, the absorption maximum was 780 nm, and the shapes of the absorption spectra were identical regardless of the ICG concentration, indicating that ICG in ethanol exists only as a monomer without H-aggregates. We found that emission was due to the monomer form and decreased with H-aggregate formation. In the fluorescence spectra, the 820 nm emission band was dominant at low concentrations, whereas at high concentrations, we found that the emission peaks were converted to 880 nm, suggesting a new form via the twisted intramolecular charge transfer (TICT) process of ICG. The NIR fluorescence intensity of ICG in ethanol was approximately 12- and 9-times brighter than in water in the NIR-I and -II regions, respectively. We propose an energy diagram of ICG to describe absorptive and emissive transitions through the ICG structures such as the monomer, H-aggregated, and TICT monomer forms.

Background

Hundreds of millions of people become infected globally every year while seeking care in health facilities that lack basic needs like infection control measures and personal protective equipment (PPE). We aimed to evaluate the availability of infection control items and PPE in eight low- and middle-income countries and identify disparities in the availability of those items.

Methods

In this study, we combined publicly available nationally representative cross-sectional health system surveys (Service Provision Assessments by the Demographic and Health Survey Programme) conducted in eight countries between 2013 and 2018: Afghanistan, Bangladesh, the Democratic Republic of the Congo, Haiti, Malawi, Nepal, Senegal, and Tanzania. The availability of infection control items was evaluated using a list of six items (a waste receptacle, a sharps container, disinfectant, single-use disposable or auto-disposable syringes, soap and running water, or an alcohol-based hand rub, and guidelines for standard precautions). PPE includes four items: gloves, medical masks, gowns, and eye protection. We considered these items available in a facility if they were observed in general outpatient areas or any service-specific area (i.e. delivery room).

Results

We analysed data from 7948 health facilities (694 hospitals and 7254 health centres/clinics). Overall, among the infection control items and PPE, most surveyed facilities had high availability of single-use disposable or auto-disposable syringes (91.40%) and latex gloves (92.56%). Of infection control measures, guidelines for infection control were the least available during the survey, with the lowest (6.15%) in Nepal and the highest (68.18%) in Malawi. Of the PPE items, eye protection was the least available during the survey, with the lowest (5.4% in Senegal) and the highest (28.17%) in Haiti. Only 1567 (19.71%) facilities looked to have all the basic infection control materials, and 1023 (12.87%) of the analysed facilities possessed all of the PPE. Within the same country, the availability of items varied more between hospitals and health centres/clinics than between them.

Conclusions

All eight of our study countries experience shortages of the most fundamental standard precaution items to avert infection. Steps must be taken in each of these countries to reduce inadequacies and disparities and enhance efficiency in the conversion of health-system inputs into the facility's availability of standard precaution items for infection control - to curb the risk of infectious disease transmission.

Background

Gestational age (GA) is frequently unknown or inaccurate in pregnancies in low-income countries. Early identification of preterm infants may help link them to potentially life-saving interventions.

Methods

We conducted a validation study in a community-based birth cohort in rural Bangladesh. GA was determined by pregnancy ultrasound (<20 weeks). Community health workers conducted home visits (<72 hours) to assess physical/neuromuscular signs and measure anthropometrics. The distribution, agreement, and diagnostic accuracy of different clinical methods of GA assessment were determined compared with early ultrasound dating.

Results

In the live-born cohort (n = 1066), the mean ultrasound GA was 39.1 weeks (SD 2.0) and prevalence of preterm birth (<37 weeks) was 11.4%. Among assessed newborns (n = 710), the mean ultrasound GA was 39.3 weeks (SD 1.6) (8.3% preterm) and by Ballard scoring the mean GA was 38.9 weeks (SD 1.7) (12.9% preterm). The average bias of the Ballard was -0.4 weeks; however, 95% limits of agreement were wide (-4.7 to 4.0 weeks) and the accuracy for identifying preterm infants was low (sensitivity 16%, specificity 87%). Simplified methods for GA assessment had poor diagnostic accuracy for identifying preterm births (community health worker prematurity scorecard [sensitivity/specificity: 70%/27%]; Capurro [5%/96%]; Eregie [75%/58%]; Bhagwat [18%/87%], foot length <75 mm [64%/35%]; birth weight <2500 g [54%/82%]). Neonatal anthropometrics had poor to fair performance for classifying preterm infants (areas under the receiver operating curve 0.52-0.80).

Conclusions

Newborn clinical assessment of GA is challenging at the community level in low-resource settings. Anthropometrics are also inaccurate surrogate markers for GA in settings with high rates of fetal growth restriction.