Haemoglobin diagnostic cut-offs for anaemia in Indian women of reproductive age.

BACKGROUND: The persistent high prevalence of anaemia among Indian women of reproductive age (WRA) despite aggressive long-term iron supplementation could be related to over-diagnosis from an inappropriately high haemoglobin (Hb) diagnostic cut-off. To develop an appropriate cut-off for Indian WRA, we hypothesized that during iron-folic acid (IFA) supplementation to a mixed (anaemic/non-anaemic) WRA population, the positive slope of the Hb-plasma ferritin (PF) response in anaemic women would inflect into a plateau (zero-response) as a non-anaemic status is reached. The 2.5th percentile of the Hb distribution at this inflection point will be the diagnostic Hb cut-off for iron-responsive anaemia. METHOD: A hierarchical mixed effects model, with a polynomial mean and variance model to account for intraclass correlation due to repeated measures, was used to estimate the response curve of Hb to PF, or body iron stores, in anaemic and non-anaemic WRA (without inflammation), who were receiving a 90-day IFA supplementation. RESULTS: The Hb response curve at low PF values showed a steep increase, which inflected into a plateau at a PF of 10.1 µg/L and attained a steady state at a PF of 20.6 µg/L. The Hb distribution at the inflection was a normal probability distribution, with a mean of 12.3 g/dL. The 2.5th percentile value of this distribution, or the putative diagnostic Hb cut-off for anaemia, was 10.8 g/dL (~11 g/dL). CONCLUSION: The derived Hb cut-off is lower than the current adult values of 12 g/dL and could partly explain the persistently high prevalence of anaemia.

Shooting shadows: India's struggle to reduce the burden of anaemia.

Despite several efforts by the Government of India, the national burden of anaemia remains high and its growing prevalence (between 2015-2016 and 2019-2021) is concerning to India's public health system. This article reviews existing food-based and clinical strategies to mitigate the anaemia burden and why they are premature and insufficient. In a context where multiple anaemia control programmes are in play, this article proposes a threefold strategy for consideration. First, except the Comprehensive National Nutrition Survey, 2016-2018, which measured Hb concentration among children and adolescents aged 1-19 years using venous blood samples, all national surveys use capillary blood samples to determine Hb levels, which could be erroneous. The Indian government should prioritise conducting a nationwide survey for estimating the burden of anaemia and its clinical determinants for all age groups using venous blood samples. Second, without deciding the appropriate dose of Fe needed for an individual, food fortification programmes that are often compounded with layering of other micronutrients could be harmful and further research on this issue is needed. Same is true for the pharmacological intervention of Fe tablet or syrup supplementation programmes, which is given to individuals without assessing its need. In addition, there is a dire need for robust research to understand both the long-term benefit and side effects of Fe supplementation programmes. Third and final, the WHO is in process of reviewing the Hb threshold for defining anaemia, therefore the introduction of new anaemia control programmes should be restrained.

Fermented Foods: Are They Tasty Medicines for Helicobacter pylori Associated Peptic Ulcer and Gastric Cancer?

More than a million people die every year due to gastric cancer and peptic ulcer. Helicobacter pylori infection in stomach is the most important reason for these diseases. Interestingly, only 10-20% of the H. pylori infected individuals suffer from these gastric diseases and rest of the infected individuals remain asymptomatic. The genotypes of H. pylori, host genetic background, lifestyle including smoking and diet may determine clinical outcomes. People from different geographical regions have different food habits, which also include several unique fermented products of plant and animal origins. When consumed raw, the fermented foods bring in fresh inocula of microbes to gastrointestinal tract and several strains of these microbes, like Lactobacillus and Saccharomyces are known probiotics. In vitro and in vivo experiments as well as clinical trials suggest that several probiotics have anti-H. pylori effects. Here we discuss the possibility of using natural probiotics present in traditional fermented food and beverages to obtain protection against H. pylori induced gastric diseases.

A novel, broad-range, CTXΦ-derived stable integrative expression vector for functional studies.

CTXΦ, a filamentous vibriophage encoding cholera toxin, uses a unique strategy for its lysogeny. The single-stranded phage genome forms intramolecular base-pairing interactions between two inversely oriented XerC and XerD binding sites (XBS) and generates a functional phage attachment site, attP(+), for integration. The attP(+) structure is recognized by the host-encoded tyrosine recombinases XerC and XerD (XerCD), which enables irreversible integration of CTXΦ into the chromosome dimer resolution site (dif) of Vibrio cholerae. The dif site and the XerCD recombinases are widely conserved in bacteria. We took advantage of these conserved attributes to develop a broad-host-range integrative expression vector that could irreversibly integrate into the host chromosome using XerCD recombinases without altering the function of any known open reading frame (ORF). In this study, we engineered two different arabinose-inducible expression vectors, pBD62 and pBD66, using XBS of CTXΦ. pBD62 replicates conditionally and integrates efficiently into the dif of the bacterial chromosome by site-specific recombination using host-encoded XerCD recombinases. The expression level of the gene of interest could be controlled through the PBAD promoter by modulating the functions of the vector-encoded transcriptional factor AraC. We validated the irreversible integration of pBD62 into a wide range of pathogenic and nonpathogenic bacteria, such as V. cholerae, Vibrio fluvialis, Vibrio parahaemolyticus, Escherichia coli, Salmonella enterica, and Klebsiella pneumoniae. Gene expression from the PBAD promoter of integrated vectors was confirmed in V. cholerae using the well-studied reporter genes mCherry, eGFP, and lacZ.

The role of Vibrio cholerae genotyping in Africa.

Toxigenic Vibrio cholerae, the causative agent of the disease cholera, is prevalent in the African continent from the 1970s when the seventh pandemic spread from Asia to Africa. In the past decade, cholera has caused devastating outbreaks in much of Africa, illustrated by the recent cholera epidemics in Zimbabwe and regions of central Africa. Given the extent of cholera in Africa, a robust and efficient surveillance system should be in place to prevent and control the disease in this continent. Such a surveillance system would be greatly bolstered by use of molecular typing techniques to identify genetic subtypes. In this review, we highlight the role that modern molecular typing techniques can play in tracking and aborting the spread of cholera.

Diarrheagenic pathogens in polymicrobial infections.

During systematic active surveillance of the causes of diarrhea in patients admitted to the Infectious Diseases and Beliaghata General Hospital in Kolkata, India, we looked for 26 known gastrointestinal pathogens in fecal samples from 2,748 patients. Samples from about one-third (29%) of the patients contained multiple pathogens. Polymicrobial infections frequently contained Vibrio cholerae O1 and rotavirus. When these agents were present, some co-infecting agents were found significantly less often (p = 10 (-5) to 10 (-33), some were detected significantly more often (p = 10 (-5) to 10 (-26), and others were detected equally as often as when V. cholerae O1 or rotavirus was absent. When data were stratified by patient age and season, many nonrandom associations remained statistically significant. The causes and effects of these nonrandom associations remain unknown.