Prevalence and associated risk factors of Helicobacter pylori infection in East Africa: a systematic review and meta-analysis.

BACKGROUND: Helicobacter pylori is the main cause of chronic gastritis, peptic ulcer, lymphoma, and gastric cancer in humans. The prevalence and factors associated with H. pylori infection are varied across countries. Thus, a comprehensive review has not been done on prevalence and associated factors in East Africa. Therefore, this systematic review and meta-analysis aimed to estimate the pooled prevalence and identify factors associated with H. pylori infection in East Africa. METHODS: Articles written in English language were retrieved from PubMed, Scopus, and Science Direct. Relevant articles were selected and screened using Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Publication bias was assessed qualitatively and qualitatively using funnel plot symmetry and Egger's test, respectively. Heterogeneity was assessed using the I2 measure. Data were analyzed using Stata software, version 14, and the "metan" command. RESULTS: A total of 231 articles were retrieved from nineteen countries in East Africa. Of these, 70 articles were eligible for the review. The pooled prevalence of H. pylori in East Africa was 50.98% (95% CI: 45.05-56.90). The prevalence of H. pylori infection ranged from 7.7 to 94.5% in East African countries. The highest pooled prevalence was from Sudan (61.3%, 95% CI: 52.6-69.9), and the lowest prevalence was reported from Uganda (40.7%, 95% CI: 33-48.3). Persons with no formal education (OR: 2.03; 95% CI: 1.22-2.83), lack of hand washing habit after toilet (OR: 2.24; 95% CI: 1.45-3.02), having a history of dyspepsia (OR: 2.25; 95% CI: 1.31-3.18), living in rural areas (OR = 1.80; 95% CI: 0.38-3.23), and having unclean water source (OR = 1.5; 95% CI:0.45-3.45) were all associated with higher risk for H. pylori infection. CONCLUSION: More than half of the populations of East African countries were positive for H. pylori infection. Rural residence, source of water, and alcohol consumption were significantly associated with H. pylori infection. Therefore, healthcare workers could provide health education on the aforementioned risk factors, and the government and other stakeholders could improve the source of drinking water in East Africa.

Apoio institucional para agentes comunitários de saúde usando o programa de Atenção Integrada às Doenças Prevalentes na Infância em Ruanda / Institutional support to community health workers using integrated management of childhood illness program in Rwanda

O objetivo foi explorar o apoio e descrever a supervisão de agentes comunitários de saúde que implementam o programa de atenção integrada às doenças prevalentes na infância (AIDPI). Um desenho não experimental, exploratório, descritivo e quantitativo foi adotado neste estudo. Os dados foram coletados entre 305 participantes (30% da população) por meio de um questionário estruturado. Dupla digitação foi utilizada e os dados foram limpos e analisados usando o Statistics Package of Social Sciences (SPSS) 19. Em Ruanda, o apoio e supervisão são fornecidos pela instituição base e supervisores. Os agentes comunitários de saúde (ACS) frequentemente enfrentam escassez de medicamentos e equipamentos (63,3%) e 87,5% ficaram sem equipamentos, medicamentos e consumíveis, o que criou barreiras para a assistência das crianças doentes. Para melhorar o apoio institucional dado aos agentes comunitários de saúde, supervisão de apoio contínua e regular, além do fornecimento de suprimentos, é essencial.

The objective was to explore the support given to community health workers who use the integrated management of childhood illness (IMCI) approach and describe the supervision given to them. A non-experimental, exploratory, descriptive, quantitative design was used for this study. Data were collected using a structured questionnaire; 305 were interviewed (30% sample). The data were double entered, cleaned, and analyzed using Statistics Package of Social Sciences (SPSS) 19. Support and supervision in Rwanda are provided by the base institution and by supervisors. CHWs often had a shortage of drugs and equipment (63.3%) and 87.5% have experienced run out of equipment, medicines, and consumables. This created barriers to caring for sick children. To improve institutional support for community health workers, regular and continuous supportive supervision and supplies are essential.

COVID-19 in East and Southern Africa: Rebuilding Differently and Better Must Start Now.

By June 2020, the cumulative cases and deaths related to COVID-19 in 16 East and Southern African (ESA) countries were still rising, with an average case fatality rate of 1.46%.[1] From its initial presence in cities and regional transport hubs, cases are spreading, including to rural areas, among health workers and as migrants cross borders to return home.[2].

Early detection and treatment strategies for breast cancer in low-income and upper middle-income countries: a modelling study.

BACKGROUND: Poor breast cancer survival in low-income and middle-income countries (LMICs) can be attributed to advanced-stage presentation and poor access to systemic therapy. We aimed to estimate the outcomes of different early detection strategies in combination with systemic chemotherapy and endocrine therapy in LMICs. METHODS: We adapted a microsimulation model to project outcomes of three early detection strategies alone or in combination with three systemic treatment programmes beyond standard of care (programme A): programme B was endocrine therapy for all oestrogen-receptor (ER)-positive cases; programme C was programme B plus chemotherapy for ER-negative cases; programme D was programme C plus chemotherapy for advanced ER-positive cases. The main outcomes were reductions in breast cancer-related mortality and lives saved per 100 000 women relative to the standard of care for women aged 30-49 years in a low-income setting (East Africa; using incidence data and life tables from Uganda and data on tumour characteristics from various East African countries) and for women aged 50-69 years in a middle-income setting (Colombia). FINDINGS: In the East African setting, relative mortality reductions were 8-41%, corresponding to 23 (95% uncertainty interval -12 to 49) to 114 (80 to 138) lives saved per 100 000 women over 10 years. In Colombia, mortality reductions were 7-25%, corresponding to 32 (-29 to 70) to 105 (61 to 141) lives saved per 100 000 women over 10 years. INTERPRETATION: The best projected outcomes were in settings where access to both early detection and adjuvant therapy is improved. Even in the absence of mammographic screening, improvements in detection can provide substantial benefit in settings where advanced-stage presentation is common. FUNDING: Fred Hutchinson Cancer Research Center/University of Washington Cancer Consortium Cancer Center Support Grant of the US National Institutes of Health.

Inferring population dynamics of HIV-1 subtype C epidemics in Eastern Africa and Southern Brazil applying different Bayesian phylodynamics approaches.

The subtype C Eastern Africa clade (CEA), a particularly successful HIV-1 subtype C lineage, has seeded several sub-epidemics in Eastern African countries and Southern Brazil during the 1960s and 1970s. Here, we characterized the past population dynamics of the major CEA sub-epidemics in Eastern Africa and Brazil by using Bayesian phylodynamic approaches based on coalescent and birth-death models. All phylodynamic models support similar epidemic dynamics and exponential growth rates until roughly the mid-1980s for all the CEA sub-epidemics. Divergent growth patterns, however, were supported afterwards. The Bayesian skygrid coalescent model (BSKG) and the birth-death skyline model (BDSKY) supported longer exponential growth phases than the Bayesian skyline coalescent model (BSKL). The BDSKY model uncovers patterns of a recent decline for the CEA sub-epidemics in Burundi/Rwanda and Tanzania (Re < 1) and a recent growth for Southern Brazil (Re > 1); whereas coalescent models infer an epidemic stabilization. To the contrary, the BSKG model captured a decline of Ethiopian CEA sub-epidemic between the mid-1990s and mid-2000s that was not uncovered by the BDSKY model. These results underscore that the joint use of different phylodynamic approaches may yield complementary insights into the past HIV population dynamics.

Oesophageal cancer.

Oesophageal cancer is the sixth most common cause of cancer-related death worldwide and is therefore a major global health challenge. The two major subtypes of oesophageal cancer are oesophageal squamous cell carcinoma (OSCC) and oesophageal adenocarcinoma (OAC), which are epidemiologically and biologically distinct. OSCC accounts for 90% of all cases of oesophageal cancer globally and is highly prevalent in the East, East Africa and South America. OAC is more common in developed countries than in developing countries. Preneoplastic lesions are identifiable for both OSCC and OAC; these are frequently amenable to endoscopic ablative therapies. Most patients with oesophageal cancer require extensive treatment, including chemotherapy, chemoradiotherapy and/or surgical resection. Patients with advanced or metastatic oesophageal cancer are treated with palliative chemotherapy; those who are human epidermal growth factor receptor 2 (HER2)-positive may also benefit from trastuzumab treatment. Immuno-oncology therapies have also shown promising early results in OSCC and OAC. In this Primer, we review state-of-the-art knowledge on the biology and treatment of oesophageal cancer, including screening, endoscopic ablative therapies and emerging molecular targets, and we discuss best practices in chemotherapy, chemoradiotherapy, surgery and the maintenance of patient quality of life.

Modelling the global competing risks of a potential interaction between injectable hormonal contraception and HIV risk.

BACKGROUND: Some, but not all, observational studies have suggested an increase in the risk of HIV acquisition for women using injectable hormonal contraception (IHC). METHODS: We used country-level data to explore the effects of reducing IHC use on the number of HIV infections, the number of live births and the resulting net consequences on AIDS deaths and maternal mortality for each country. RESULTS: High IHC use coincides with high HIV incidence primarily in southern and eastern Africa. If IHC increases the risk of HIV acquisition, this could generate 27 000-130 000 infections per year globally, 87-88% of which occur in this region. Reducing IHC use could result in fewer HIV infections but also a substantial increase in live births and maternal mortality in countries with high IHC use, high birth rates and high maternal mortality: mainly southern and eastern Africa, South-East Asia, and Central and South America. For most countries, the net impact of reducing IHC use on maternal and AIDS-related deaths is dependent on the magnitude of the assumed IHC-HIV interaction. CONCLUSIONS: If IHC use increases HIV acquisition risk, reducing IHC could reduce new HIV infections; however, this must be balanced against other important consequences, including unintended pregnancy, which impacts maternal and infant mortality. Unless the true effect size approaches a relative risk of 2.19, it is unlikely that reductions in IHC could result in public health benefit, with the possible exception of those countries in southern Africa with the largest HIV epidemics.

Phylodynamics of HIV-1 subtype C epidemic in east Africa.

The HIV-1 subtype C accounts for an important fraction of HIV infections in east Africa, but little is known about the genetic characteristics and evolutionary history of this epidemic. Here we reconstruct the origin and spatiotemporal dynamics of the major HIV-1 subtype C clades circulating in east Africa. A large number (n = 1,981) of subtype C pol sequences were retrieved from public databases to explore relationships between strains from the east, southern and central African regions. Maximum-likelihood phylogenetic analysis of those sequences revealed that most (>70%) strains from east Africa segregated in a single regional-specific monophyletic group, here called C(EA). A second major Ethiopian subtype C lineage and a large collection of minor Kenyan and Tanzanian subtype C clades of southern African origin were also detected. A bayesian coalescent-based method was then used to reconstruct evolutionary parameters and migration pathways of the C(EA) African lineage. This analysis indicates that the C(EA) clade most probably originated in Burundi around the early 1960s, and later spread to Ethiopia, Kenya, Tanzania and Uganda, giving rise to major country-specific monophyletic sub-clusters between the early 1970s and early 1980s. The results presented here demonstrate that a substantial proportion of subtype C infections in east Africa resulted from dissemination of a single HIV local variant, probably originated in Burundi during the 1960s. Burundi was the most important hub of dissemination of that subtype C clade in east Africa, fueling the origin of new local epidemics in Ethiopia, Kenya, Tanzania and Uganda. Subtype C lineages of southern African origin have also been introduced in east Africa, but seem to have had a much more restricted spread.

Celiac disease in the developing countries: a new and challenging public health problem.

In the past, celiac disease was believed to be a chronic enteropathy, almost exclusively affecting people of European origin. The availability of new, simple, very sensitive and specific serological tests (anti-gliadin, anti-endomysium and anti-transglutaminase antibody assays) have shown that celiac disease is common not only in Europe and in people of European ancestry but also in the developing countries where the major staple diet is wheat (Southern Asia, the Middle East, North West and East Africa, South America), both in the general population and in the groups at risk. Gluten intolerance thus appears to be a widespread public health problem and an increased level of awareness and clinical suspicion are needed in the New World where physicians must learn to recognize the variable clinical presentations (classical, atypical and silent forms) of celiac disease. In the developing countries, both serological screening in the general population and serological testing in groups at risk are necessary for an early identification of celiac patients. The gluten-free diet poses a challenging public health problem in the developing countries, especially since commercial gluten-free products are not available.

Hepatitis B virus genotypes and HBsAg subtypes in refugees and injection drug users in the United States determined by LiPA and monoclonal EIA.

Hepatitis B virus (HBV) genotyping and hepatitis B surface antigen (HBsAg) subtyping were carried out on sera from 196 HBsAg-positive patients, including 151 refugees entering the United States and 45 injection drug users in Seattle. HBsAg subtyping was performed by enzyme immunoassay (EIA) using a panel of monoclonal antibodies and the HBV genotype was determined by polymerase chain reaction (PCR) followed by detection of amplified HBV DNA by a reverse-phase hybridization line probe assay (LiPA) using genotype-specific probes. HBV DNA was detected by PCR in 155 (79%) of the 196 sera and all 155 were genotyped by LiPA. Samples from Southeast Asia were predominantly genotype B/subtype ayw1 and genotype C/adr; samples from the former Soviet Union and eastern Europe were mostly genotype D/ayw2 and genotype D/ayw3; samples from east Africa were mainly genotype A/adw2 and genotype D/ayw2; and samples from injection drug users were mostly genotype D/ayw3 and genotype A/adw2. Some strains of ayw3 gave atypical monoclonal antibody reactivity patterns in the subtyping assay due to a Val/Ala instead of a Thr at amino acid residue 118 and a Thr instead of a Met at residue 125. A strain of ayw2 also gave an atypical monoclonal antibody reactivity pattern due to an Ala instead of a Thr at amino acid residue 123. LiPA genotyping and monoclonal EIA subtyping can provide useful information for epidemiological studies.

Prevalence of antibodies to Neospora caninum in different canid populations.

A total of 1,554 dogs from 5 countries on 3 continents were tested for antibodies to Neospora caninum using an indirect fluorescent antibody test. In Australia, overall, 42/451 (9%, 95% confidence interval [CI] 6-12%) dogs were seropositive (Melbourne 11/207 [5%, 95% CI 2-9%]; Sydney 18/150 [12%, 95% CI 7-18%]; Perth 13/94 [14%, 95% CI 8-22%]). Antibodies to N. caninum were also detected in dogs in South America (Uruguay [20%, 95% CI 16-24%, n = 414]) and sub-Saharan Africa (Tanzania [22%, 95% CI 12-36%, n = 49]). In contrast, only 1 of 500 dogs tested from the Falkland Islands and none of 140 dogs from Kenya was seropositive. Of wild canids, 1/54 (2%, 95% CI 0-10%) British foxes and 15/169 (9%, 95% CI 5-14%) Australian dingoes had antibodies to N. caninum.

Variations in familial neonatal mortality risks in four countries.

This paper investigates variations in the strength and structure of familial association in neonatal mortality risks in four populations; Bolivia, Kenya, Peru, and Tanzania. Exploratory analyses of the structure of the familial association are presented for each population. Random effects logistic models are then used to estimate the strength of familial association in neonatal mortality risks using a standard set of control variables. The results suggest that the strength of familial association in neonatal mortality risks is quite similar in these four populations which would be consistent with a biological explanation for the association. However, some differences were found, particularly in the form of the association in Peru, which may suggest at least a small role of other factors.

[Towards a vaccination against malaria]. / Vers une vaccination contre le paludisme.

For 20 years, the prospect of anti-malarial vaccination has aroused many hopes, but in the end, it has mostly given rise to doubts and disappointment. If most attempts have been to no avail, this is because the issue at stake is amazingly difficult. Besides the very complex antigenic structure of the protozoa Plasmodium, there is first the existence of at least three different targets during the plasmodial cycle, then the necessity of appropriate adjuvants and, most of all, the imperfection of our experimental models. Recently, Pattaroyo and the various groups who worked with him have eventually met success with vaccine trials in man: they used a synthetic antigene, SPf66, on volunteers in South America, then on a larger population sample in East Africa. The results are still quite modest: people are protected against the malarial disease but not against the parasitemia and only in approximately 40% of cases. Nevertheless, these results have the merit of representing the first successful anti-malarial vaccination in man. Although great advances are still needed, a decisive step forward has been taken. Other types of vaccine will soon be tested by other groups (anti-gametocyte vaccines) and prospects of significant improvements are offered by the technique of DNA-vaccines. If it is now certain that one or several vaccines will be available in a near future, no one is able to set the time delay necessary to reach this stage. In any case, hoping that this type of vaccine will eradicate the disease is not realistic since a disease as complex as malaria, in terms of epidemiology, cannot be eliminated by only one method.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative prevalences of Ascaris lumbricoides, Trichuris trichiura and hookworm infections and the prospects for combined control.

Programmes to control Ascaris lumbricoides, Trichuris trichiura and hookworm infections have often been targeted at each infection separately, but the advent of benign and broad-spectrum anthelmintics suggests that combined control may be feasible. The extent to which the infections co-occur in communities will determine the need for, and potential benefits of, such a combined approach. This paper examines the comparative distribution of the three geohelminths in different geographical areas and shows that A. lumbricoides and T. trichiura have closely related distributions, while hookworm infection is largely independent of the other two. These results indicate that many communities are at risk of disease from infection by more than one species of helminth. The similar distributions and epidemiological characteristics of A. lumbricoides and T. trichiura suggest that simultaneous control of these two parasites by the same strategy would be feasible and highly beneficial to communities. Multiple species control strategies which aim to control hookworm infection may require a more complicated protocol with more precise locality targeting.

[Epidemiology of HTLV-I infection in its hyperendemic foci (Japan, tropical Africa, Caribbean)]. / Epidémiologie de l'infection par HTLV-I dans ses foyers d'hyperendémie (Japon, Afrique intertropicale, Caraïbes).

HTLV-1 infection is endemic in Japan, black Africa, the Caribbean and several regions of South America. In these foci, the infections is very heterogeneously distributed (variations from village to village, intrafamilial clustering). The virus is transmitted from mother to child, and breast feedings seems to play a major role. Sexual transmission is usually from man to woman. The frequency of transmission by blood transfusion must not be underestimated. It justifies the systematic detection of HTLV-1 infection in areas where it is economically feasible.