A physical mechanism for North Atlantic SST influence on the Indian summer monsoon

A link between the Atlantic Multidecadal Oscillation (AMO) and multidecadal variability of the Indian summer monsoon rainfall is unraveled and a long sought physical mechanism linking Atlantic climate and monsoon has been identified. The AMO produces persistent weakening (strengthening) of the meridional gradient of tropospheric temperature (TT) by setting up negative (positive) TT anomaly over Eurasia during northern late summer/autumn resulting in early (late) withdrawal of the south west monsoon and persistent decrease (increase) of seasonal monsoon rainfall. On inter-annual time scales, strong North Atlantic Oscillation (NAO) or North Annular mode (NAM) influences the monsoon by producing similar TT anomaly over Eurasia. The AMO achieves the interdecadal modulation of the monsoon by modulating the frequency of occurrence of strong NAO/NAM events. This mechanism also provides a basis for explaining the observed teleconnection between North Atlantic temperature and the Asian monsoon in paleoclimatic proxies

The Dynamics of the Southwest Monsoon Current in 2016 from High-Resolution In Situ Observations and Models

The strong stratification of the Bay of Bengal (BoB) causes rapid variations in sea surface temperature (SST) that influence the development of monsoon rainfall systems. This stratification is driven by the salinity difference between the fresh surface waters of the northern bay and the supply of warm, salty water by the Southwest Monsoon Current (SMC). Despite the influence of the SMC on monsoon dynamics, observations of this current during the monsoon are sparse. Using data from high-resolution in situ measurements along an east–west section at 8°N in the southern BoB, we calculate that the northward transport during July 2016 was between 16.7 and 24.5 Sv (1 Sv ≡ 106 m3 s−1), although up to ⅔ of this transport is associated with persistent recirculating eddies, including the Sri Lanka Dome. Comparison with climatology suggests the SMC in early July was close to the average annual maximum strength. The NEMO 1/12° ocean model with data assimilation is found to faithfully represent the variability of the SMC and associated water masses. We show how the variability in SMC strength and position is driven by the complex interplay between local forcing (wind stress curl over the Sri Lanka Dome) and remote forcing (Kelvin and Rossby wave propagation). Thus, various modes of climatic variability will influence SMC strength and location on time scales from weeks to years. Idealized one-dimensional ocean model experiments show that subsurface water masses advected by the SMC significantly alter the evolution of SST and salinity, potentially impacting Indian monsoon rainfall

The railroad switch effect of seasonally reversing currents on the Bay of Bengal high salinity core

The Southwest Monsoon Current (SMC) flows eastward from the Arabian Sea into the Bay of Bengal (BoB) during summer, advecting a core of high salinity water. This high salinity core has been linked with Arabian Sea High Salinity Water that is presumed to enter the BoB directly from the Arabian Sea via the SMC. Here we show that the high salinity core originates primarily from the western equatorial Indian Ocean, reaching the BoB via the Somali Current, the Equatorial Undercurrent and the SMC. Years with anomalously saline high salinity cores are linked with the East Africa Coastal Current and the Somali Current winter convergence, and an anomalously strong Equatorial Undercurrent. Seasonal reversals that occur at the Somali Current and SMC junctions act as 'railroad switches' diverting water masses to different basins in the northern Indian Ocean. Interannual fluctuations of the Equatorial Undercurrent are linked to wind stress and El Nino

Molecular epidemiology of Klebsiella pneumoniae invasive infections over a decade at Kilifi County Hospital in Kenya.

Multidrug resistant (MDR) Klebsiella pneumoniae is a common cause of nosocomial infections worldwide. Recent years have seen an explosion of resistance to extended-spectrum ?-lactamases (ESBLs) and emergence of carbapenem resistance. Here, we examine 198 invasive K. pneumoniae isolates collected from over a decade in Kilifi County Hospital (KCH) in Kenya. We observe a significant increase in MDR K. pneumoniae isolates, particularly to third generation cephalosporins conferred by ESBLs. Using whole-genome sequences, we describe the population structure and the distribution of antimicrobial resistance genes within it. More than half of the isolates examined in this study were ESBL-positive, encoding CTX-M-15, SHV-2, SHV-12 and SHV-27, and 79% were MDR conferring resistance to at least three antimicrobial classes. Although no isolates in our dataset were found to be resistant to carbapenems we did find a plasmid with the genetic architecture of a known New Delhi metallo-?-lactamase-1 (NDM)-carrying plasmid in 25 isolates. In the absence of carbapenem use in KCH and because of the instability of the NDM-1 gene in the plasmid, the NDM-1 gene has been lost in these isolates. Our data suggests that isolates that encode NDM-1 could be present in the population; should carbapenems be introduced as treatment in public hospitals in Kenya, resistance is likely to ensue rapidly

Diversity of Mollusc Vectors of Schistosomiasis in Miti-Murhesa Health Zone, Eastern of DRC, Kabare Territory

The main objective is to inventory the vectors of bilharziasis in the aquatic ecosystems of KABARE locally in Miti-Murhesa Health zone as well as other species of aquatic molluscs in order to activate the fight against this endemic disease of this region. A total of 2762 samples were collected during our investigation period in the aquatic ecosystems in Miti-Murhesa Health Zone. We carried out field work based on shellfish sampling using appropriate methods. This sampling was carried out in 12 different sites. After collect of samples, we identified the mollusc species using the indicated identification keys, counted them and compiled them in Excel software for statistical analyses using Past software. Thus, five species of aquatic molluscs were identified. These species are Biomphalaria pfeifferi, Bulinus globosus, Pisidium casernatum, B. forskalii and Lymnaea natalensis. The species Biomphalaria pfeifferi and Bilinus globosus are intermediate hosts of intestinal schistosomiasis and urinary schistosomiasis respectively%253B while Lymnaea natalensis is the intermediate host of fasciolosis. Depending on the frequency of species, Biomphalaria pfeifferi and Lymnaea natalensis are constant species, Bulinus globosus and Psidium casernatum are accessory species and finally B. forskalii is an accidental species.Depending on the sites prospected, one species of aquatic mollusc was abundant in the aquatic ecosystems in this area%253A Biomphalaria pfeifferi%253B three species are moderately abundant%253A Lymnaea natalensis, Bulinus globosus and Pisidium casernatum, and only one is rare%253A Tomichia ventricosa. All the prospected sites are diversified in aquatic mollusc species except the Kashekesheke site, but the 2nd tarmaque site, Mulungu River and Kamulonge sites are thus the richest sites in aquatic mollusc species of Miti-Murhesa Health zone. The presence of these species clearly shows the risk of contamination of the population of Miti-Murhesa Health zone. These intermediate hosts of bilharzia are proliferating in the aquatic ecosystems of Miti-Murhesa Health zone%253B it is therefore important to recommend ways to reduce this proliferation. This study provides the basis for future ecological studies of the intermediate bilharzia host molluscs in this entity

Human candidate gene polymorphisms and risk of severe malaria in children in Kilifi, Kenya: a case-control association study

Background: Human genetic factors are important determinants of malaria risk. We investigated associations between multiple candidate polymorphisms—many related to the structure or function of red blood cells—and risk for severe Plasmodium falciparum malaria and its specific phenotypes, including cerebral malaria, severe malaria anaemia, and respiratory distress. Methods: We did a case-control study in Kilifi County, Kenya. We recruited as cases children presenting with severe malaria to the high-dependency ward of Kilifi County Hospital. We included as controls infants born in the local community between Aug 1, 2006, and Sept 30, 2010, who were part of a genetics study. We tested for associations between a range of candidate malaria-protective genes and risk for severe malaria and its specific phenotypes. We used a permutation approach to account for multiple comparisons between polymorphisms and severe malaria. We judged p values less than 0·005 significant for the primary analysis of the association between candidate genes and severe malaria. Findings: Between June 11, 1995, and June 12, 2008, 2244 children with severe malaria were recruited to the study, and 3949 infants were included as controls. Overall, 263 (12%) of 2244 children with severe malaria died in hospital, including 196 (16%) of 1233 with cerebral malaria. We investigated 121 polymorphisms in 70 candidate severe malaria-associated genes. We found significant associations between risk for severe malaria overall and polymorphisms in 15 genes or locations, of which most were related to red blood cells: ABO, ATP2B4, ARL14, CD40LG, FREM3, INPP4B, G6PD, HBA (both HBA1 and HBA2), HBB, IL10, LPHN2 (also known as ADGRL2), LOC727982, RPS6KL1, CAND1, and GNAS. Combined, these genetic associations accounted for 5·2% of the variance in risk for developing severe malaria among individuals in the general population. We confirmed established associations between severe malaria and sickle-cell trait (odds ratio [OR] 0·15, 95% CI 0·11–0·20; p=2·61 × 10−58), blood group O (0·74, 0·66–0·82; p=6·26 × 10−8), and –α3·7-thalassaemia (0·83, 0·76–0·90; p=2·06 × 10−6). We also found strong associations between overall risk of severe malaria and polymorphisms in both ATP2B4 (OR 0·76, 95% CI 0·63–0·92; p=0·001) and FREM3 (0·64, 0·53–0·79; p=3·18 × 10−14). The association with FREM3 could be accounted for by linkage disequilibrium with a complex structural mutation within the glycophorin gene region (comprising GYPA, GYPB, and GYPE) that encodes for the rare Dantu blood group antigen. Heterozygosity for Dantu was associated with risk for severe malaria (OR 0·57, 95% CI 0·49–0·68; p=3·22 × 10−11), as was homozygosity (0·26, 0·11–0·62; p=0·002). Interpretation: Both ATP2B4 and the Dantu blood group antigen are associated with the structure and function of red blood cells. ATP2B4 codes for plasma membrane calcium-transporting ATPase 4 (the major calcium pump on red blood cells) and the glycophorins are ligands for parasites to invade red blood cells. Future work should aim at uncovering the mechanisms by which these polymorphisms can result in severe malaria protection and investigate the implications of these associations for wider health. Funding: Wellcome Trust, UK Medical Research Council, European Union, and Foundation for the National Institutes of Health as part of the Bill & Melinda Gates Grand Challenges in Global Health Initiative

On the limits of sexual health literacy: Insights from Ugandan schoolgirls

This article makes the case that current conceptions of sexual health literacy have limited relevance to the Ugandan context because they assume that knowledge of unsafe sexual practices will lead to changes in behavior and lifestyle. Drawing on a longitudinal case study with 15 Ugandan schoolgirls in rural Uganda from August 2004 to September 2006, this study argues that despite being well-informed about the risks and responsibilities of sexual activity, poverty and sexual abuse severely constrained options for these young women. Although many believed in the value of abstaining from sexual activity until marriage, they engaged in transactional sex to pay for school fees, supplies, clothing, and food. Further, fear of sexual abuse, early pregnancy, and HIV–AIDS compromised attempts to embrace sexuality. The article concludes with implications of the study for research and policy on sexual health literacy in Uganda and other poorly resourced regions of the world

Postnatal depression across countries and cultures : a qualitative study

Background: Postnatal depression seems to be a universal condition with similar rates in different countries. However, anthropologists question the cross-cultural equivalence of depression, particularly at a life stage so influenced by cultural factors. Aims: To develop a qualitative method to explore whether postnatal depression is universally recognised, attributed and described and to enquire into people’s perceptions of remedies and services for morbid states of unhappiness within the context of local services. Method: The study took place in 15 centres in 11 countries and drew on three groups of informants: focus groups with new mothers, interviews with fathers and grandmothers, and interviews with health professionals.Textual analysis of these three groups was conducted separately in each centre and emergent themes compared across centres. Results: All centres described morbid unhappiness after childbirth comparable to postnatal depression but not all saw this as an illness remediable by health interventions. Conclusions: Although the findings of this study support the universality of a morbid state of unhappiness following childbirth, they also support concerns about the cross-cultural equivalence of postnatal depression as an illness requiring the intervention of health professionals; this has implications for future research

Risk of nontyphoidal Salmonella bacteraemia in African children is modified by STAT4

Nontyphoidal Salmonella (NTS) is a major cause of bacteraemia in Africa. The disease typically affects HIV-infected individuals and young children, causing substantial morbidity and mortality. Here we present a genome-wide association study (180 cases, 2677 controls) and replication analysis of NTS bacteraemia in Kenyan and Malawian children. We identify a locus in STAT4, rs13390936, associated with NTS bacteraemia. rs13390936 is a context-specific expression quantitative trait locus for STAT4 RNA expression, and individuals carrying the NTS-risk genotype demonstrate decreased interferon-gamma (IFN gamma) production in stimulated natural killer cells, and decreased circulating IFN gamma concentrations during acute NTS bacteraemia. The NTS-risk allele at rs13390936 is associated with protection against a range of autoimmune diseases. These data implicate interleukin-12-dependent IFN gamma-mediated immunity as a determinant of invasive NTS disease in African children, and highlight the shared genetic architecture of infectious and autoimmune disease.Peer reviewe