A multi-state spatio-temporal Markov model for categorized incidence of meningitis in sub-Saharan Africa

SUMMARYMeningococcal meningitis is a major public health problem in the African Belt. Despite the obvious seasonality of epidemics, the factors driving them are still poorly understood. Here, we provide a first attempt to predict epidemics at the spatio-temporal scale required for in-year response, using a purely empirical approach. District-level weekly incidence rates for Niger (1986–2007) were discretized into latent, alert and epidemic states according to pre-specified epidemiological thresholds. We modelled the probabilities of transition between states, accounting for seasonality and spatio-temporal dependence. One-week-ahead predictions for entering the epidemic state were generated with specificity and negative predictive value >99%, sensitivity and positive predictive value >72%. On the annual scale, we predict the first entry of a district into the epidemic state with sensitivity 65·0%, positive predictive value 49·0%, and an average time gained of 4·6 weeks. These results could inform decisions on preparatory actions.

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Spatio-temporal dynamics of schistosomiasis in Rwanda between 2001 and 2012: impact of the national Neglected Tropical Disease control programme

Geospatial health ◽

10.4081/gh.2017.514 ◽

2017 ◽

Vol 12 (1) ◽

Author(s):

Elias Nyandwi ◽

Tom Veldkamp ◽

Frank Badu Osei ◽

Sherif Amer

Keyword(s):

Temporal Dynamics ◽

Public Health Problem ◽

Incidence Rates ◽

Control Programme ◽

Scan Statistics ◽

Major Public Health Problem ◽

Implementation Phase ◽

Incidence Data ◽

Spatio Temporal ◽

The Impact

Schistosomiasis is recognised as a major public health problem in Rwanda. We aimed to identify the spatio-temporal dynamics of its distribution at a fine-scale spatial resolution and to explore the impact of control programme interventions. Incidence data of Schistosoma mansoni infection at 367 health facilities were obtained for the period 2001-2012. Disease cluster analyses were conducted using spatial scan statistics and geographic information systems. The impact of control interventions was assessed for three distinct sub-periods. Findings demonstrated persisting, emerging and re-emerging clusters of schistosomiasis infection across space and time. The control programme initially caused an abrupt increase in incidence rates during its implementation phase. However, this was followed by declining and disappearing clusters when the programme was fully in place. The findings presented should contribute to a better understanding of the dynamics of schistosomiasis distribution to be used when implementing future control activities, including prevention and elimination efforts.

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Molecular epidemiology and phylogeography of Schistosoma mansoni around Lake Victoria

Parasitology ◽

10.1017/s0031182010000788 ◽

2010 ◽

Vol 137 (13) ◽

pp. 1937-1949 ◽

Cited By ~ 28

Author(s):

C. J. STANDLEY ◽

N. B. KABATEREINE ◽

C. N. LANGE ◽

N. J. S. LWAMBO ◽

J. R. STOTHARD

Keyword(s):

Population Genetics ◽

Schistosoma Mansoni ◽

Molecular Epidemiology ◽

Lake Victoria ◽

Public Health Problem ◽

Human Migration ◽

Sub Saharan Africa ◽

Major Public Health Problem ◽

Sub Saharan ◽

Coi Sequences

SUMMARYIntestinal schistosomiasis continues to be a major public health problem in sub-Saharan Africa, and is endemic in communities around Lake Victoria. Interest is growing in the molecular evolution and population genetic structure of Schistosoma mansoni and we describe a detailed analysis of the molecular epidemiology and phylogeography of S. mansoni from Lake Victoria. In total, 388 cytochrome oxidase 1 (COI) sequences were obtained from 25 sites along the Ugandan, Tanzanian and Kenyan shorelines of Lake Victoria, and 122 unique barcodes were identified; 9 corresponded to previously discovered barcodes from Lakes Victoria and Albert. A subset of the data, composed of COI sequences from miracidia from 10 individual children, was used for population genetics analyses; these results were corroborated by microsatellite analysis of 4 isolates of lab-passaged adult worms. Overall, 12 barcodes were found to be shared across all 3 countries, whereas the majority occurred singly and were locally restricted. The population genetics analyses were in agreement in revealing high diversity at the level of the human host and negligible population structuring by location. The lack of correlation between genetic distance and geographical distance in these data may be attributed to the confounding influence of high intra-individual diversity as well as human migration between communities.

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Towards malaria microscopy at the point-of-contact: an assessment of the diagnostic performance of the Newton Nm1 microscope in Uganda

Parasitology ◽

10.1017/s0031182014000833 ◽

2014 ◽

Vol 141 (14) ◽

pp. 1819-1825 ◽

Cited By ~ 10

Author(s):

J. RUSSELL STOTHARD ◽

BETTY NABATTE ◽

JOSE C. SOUSA-FIGUEIREDO ◽

NARCIS B. KABATEREINE

Keyword(s):

Confidence Interval ◽

Positive Predictive Value ◽

Predictive Value ◽

Blood Cells ◽

Diagnostic Performance ◽

White Blood Cells ◽

Sub Saharan Africa ◽

Resource Poor ◽

Sub Saharan ◽

Malaria Microscopy

SUMMARYMalaria microscopy in sub-Saharan Africa is often restricted by access to light microscopes. To address this gap, a novel portable inverted monocular microscope, the Newton Nm1, was designed and is now commercially available. Its diagnostic performance was assessed in a blinded-slide trial at ×1000 (oil) of Giemsa-stained thick blood films against a conventional microscope as undertaken by four Ugandan Ministry of Health technicians. With the Newton Nm1, diagnostic performance was: sensitivity 93·5% (95% confidence interval (CI) 78·6–99·2%), specificity 100·0% (95% CI 82·4–100·0%), positive predictive value 100·0% (95% CI 88·1–100·0%) and negative predictive value 90·5% (95% CI 69·6–98·8%). Discordance was due to a systematic error underestimating parasitaemia by ~45%; when counting Plasmodium parasites against 200 white blood cells, blood films with low parasitaemia (i.e. <100 μL−1 of blood) could be overlooked and misclassified. By contrast, specificity was excellent with no false positives encountered. Whilst proven useful, especially in resource-poor environments, it is still unclear how we can ensure the uptake of the Newton Nm1 within sub-Saharan Africa.

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Plasmodium ovale: Parasite and Disease

Clinical Microbiology Reviews ◽

10.1128/cmr.18.3.570-581.2005 ◽

2005 ◽

Vol 18 (3) ◽

pp. 570-581 ◽

Cited By ~ 125

Author(s):

William E. Collins ◽

Geoffrey M. Jeffery

Keyword(s):

Public Health Problem ◽

Molecular Techniques ◽

Sub Saharan Africa ◽

Enzyme Linked Immunosorbent Assay ◽

Developmental Cycle ◽

Major Public Health Problem ◽

Plasmodium Ovale ◽

Malaria Parasites ◽

Sub Saharan

SUMMARY Humans are infected by four recognized species of malaria parasites. The last of these to be recognized and described is Plasmodium ovale. Like the other malaria parasites of primates, this parasite is only transmitted via the bites of infected Anopheles mosquitoes. The prepatent period in the human ranges from 12 to 20 days. Some forms in the liver have delayed development, and relapse may occur after periods of up to 4 years after infection. The developmental cycle in the blood lasts approximately 49 h. An examination of records from induced infections indicated that there were an average of 10.3 fever episodes of ≥101°F and 4.5 fever episodes of ≥104°F. Mean maximum parasite levels were 6,944/μl for sporozoite-induced infections and 7,310/μl for trophozoite-induced infections. Exoerythrocytic stages have been demonstrated in the liver of humans, chimpanzees, and Saimiri monkeys following injection of sporozoites. Many different Anopheles species have been shown to be susceptible to infection with P. ovale, including A. gambiae, A. atroparvus, A. dirus, A. freeborni, A. albimanus, A. quadrimaculatus, A. stephensi, A. maculatus, A. subpictus, and A. farauti. An enzyme-linked immunosorbent assay has been developed to detect mosquitoes infected with P. ovale using a monoclonal antibody directed against the circumsporozoite protein. Plasmodium ovale is primarily distributed throughout sub-Saharan Africa. It has also been reported from numerous islands in the western Pacific. In more recent years, there have been reports of its distribution on the Asian mainland. Whether or not it will become a major public health problem there remains to be seen. The diagnosis of P. ovale is based primarily on the characteristics of the blood stages and its differentiation from P. vivax. The sometimes elliptical shape of the infected erythrocyte is often diagnostic when combined with other, subtler differences in morphology. The advent of molecular techniques, primarily PCR, has made diagnostic confirmation possible. The development of techniques for the long-term frozen preservation of malaria parasites has allowed the development diagnostic reference standards for P. ovale. Infections in chimpanzees are used to provide reference and diagnostic material for serologic and molecular studies because this parasite has not been shown to develop in other nonhuman primates, nor has it adapted to in vitro culture. There is no evidence to suggest that P. ovale is closely related phylogenetically to any other of the primate malaria parasites that have been examined.

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Seroprevalence of Hepatitis B and C among Healthcare Workers in Dutse Metropolis Jigawa State, Nigeria

10.1101/327940 ◽

2018 ◽

Author(s):

N.M. Sani ◽

I. Bitrus ◽

A.M. Sarki ◽

N.S. Mujahid

Keyword(s):

Health Care ◽

Hepatitis B ◽

Health Care Workers ◽

Healthcare Workers ◽

Public Health Problem ◽

Sub Saharan Africa ◽

Chromatographic Technique ◽

Major Public Health Problem ◽

Care Workers ◽

Sub Saharan

AbstractHepatitis is one of the neglected infectious diseases in sub Saharan Africa and most of the available data is based on blood donors. Health care workers (HCWs) often get infected as a result of their close contact with patients. A cross sectional study was conducted to determine the prevalence of hepatitis B and C among this group of professionals with a view to improving the quality of care to their patients. Hepatitis B and C infections pose a major public health problem worldwide. While infection is highest in the developing world particularly Asia and sub-Saharan Africa, healthcare workers are at higher risk of acquiring blood-borne viral infections, particularly Hepatitis B and C which are mostly asymptomatic. This study was aimed at determining the prevalence of Hepatitis B and C infections and associated risk factors among health care workers in Dutse Metropolis, Jigawa State - Nigeria. A standard rapid immuno-chromatographic technique i.e. rapid ELISA was used to screen all sera for Hepatitis B surface antigen (HBsAg) and Hepatitis C viral antibody (HCVAb) respectively. Strips containing coated antibodies and antigens to HBV and HCV respectively were removed from the foil. Strips were labeled according to samples. Using a separate disposable pipette, 2 drops of the sample (plasma) were added into each test strip and allowed to run across the absorbent pad. Results were read after 15 minutes. The prevalence of HBV and HCV infection in 100 healthcare workers was determined by testing the plasma collected from the clients during their normal checkup using HBsAg and HCVAb test strips. Results were subjected to statistical analysis using chi-square test. The prevalence of HBV among HCWs was 19 out of 100 (19.0%) and that of HCV was 5 out of 100 (5.0%) where in both cases, higher prevalence was observed among female nurses. It was also observed that all HCV positive cases were recorded among nurses only. The study revealed that nurses are at greater risk of contracting HBV and HCV due to their frequent contact with patients. It is therefore recommended that effective vaccination and other infection control measures be encouraged among healthcare workers.

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Rasmussen syndrome in a tropical environment: a study of six (6) observations

The Egyptian Journal of Neurology Psychiatry and Neurosurgery ◽

10.1186/s41983-021-00409-x ◽

2021 ◽

Vol 57 (1) ◽

Author(s):

Carlos Othon Guelngar ◽

Touré Mohamed Lamine ◽

Barry Mamadou Ciré ◽

Diakité Mamady ◽

Konaté Mahadi ◽

...

Keyword(s):

Public Health ◽

Valproic Acid ◽

Analytical Study ◽

Public Health Problem ◽

Epileptic Seizures ◽

Sub Saharan Africa ◽

Major Public Health Problem ◽

Mental Deterioration ◽

Rasmussen Syndrome ◽

Sub Saharan

Abstract Background In sub-Saharan Africa, encephalitis of various etiologies is a major public health problem and Rasmussen syndrome is rarely diagnosed due to under-medicalization. The objective of this study is to describe the clinical and neuroradiological forms, especially since this affection is little known in sub-Saharan Africa as evidenced by the scarcity of publications. Results A retrospective, descriptive and analytical study of six (6) cases of Rasmussen syndrome, shows that it is an unrecognized disease in Africa. Men were more represented with a frequency of 67% with a young age. The clinical picture dominated by 100% seizures, mental deterioration and hemiparesis. The etiology is still questionable, probably autoimmune in our study. Conclusion Rasmussen syndrome accounts for 3% in 219 patients hospitalized for epileptic conditions. This study shows a clinical profile dominated by recurrent epileptic seizures refractory to the drugs Phenobarbital, Valproic Acid and Carbamazepine, the only antiepileptics available in the country. These results are valid for therapeutic and prognostic discussion.

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Preterm birth and associated factors among mothers who gave birth in Dire Dawa, Ethiopia

British Journal of Midwifery ◽

10.12968/bjom.2021.29.6.338 ◽

2021 ◽

Vol 29 (6) ◽

pp. 338-345

Author(s):

Alekaw Sema ◽

Nigus Kassie ◽

Bezabih Amsalu ◽

Yalelet Belay ◽

Alemu Guta ◽

...

Keyword(s):

Preterm Birth ◽

Associated Factors ◽

Public Health Problem ◽

Cross Sectional Study ◽

Sub Saharan Africa ◽

Major Public Health Problem ◽

Cross Sectional ◽

Eastern Ethiopia ◽

Dire Dawa ◽

Sub Saharan

Background The highest rate of preterm birth in the world is in Sub-Saharan Africa and Asia. However, there is limited data in this study area. Therefore, this study aims to assess the prevalence and associated factors of preterm birth in Dire Dawa City, Eastern Ethiopia. Method An institutional-based, cross-sectional study was conducted with 420 respondents. Conclusion Preterm birth is still a major public health problem in Dire Dawa City.

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Characterization of Spatio-Temporal Trends and Periodicity of Precipitation over Malawi during 1979–2015

Atmosphere ◽

10.3390/atmos11090891 ◽

2020 ◽

Vol 11 (9) ◽

pp. 891

Author(s):

Edwin Tadeyo ◽

Dan Chen ◽

Brian Ayugi ◽

Chunzhen Yao

Keyword(s):

Spatial Distribution ◽

Function Analysis ◽

Temporal Trends ◽

Sub Saharan Africa ◽

Spatial And Temporal Variability ◽

Wet Season ◽

Climate Change And Variability ◽

Spatio Temporal ◽

Sub Saharan ◽

Annual Scale

Precipitation remains the key climatic parameter in sub-Saharan Africa, as it drives the economy through rain-fed agricultural production. Malawi is one of the countries most susceptible to the impacts of climate change and variability. This paper presents the characteristics of spatio-temporal trends and periodicity of precipitation in Malawi in the period from 1979 to 2015. The analysis was based on recent rain ground gauge data. In total, 31 out of 36 rainfall stations, which include some key stations from the southeast of Malawi, were selected for the study after robust homogeneity tests were applied to the datasets. Spatial distribution of annual mean precipitation showed that high amounts of rainfall are located in areas along the lake and the southeast part of Malawi. The spatial distribution of the wet season (November to April) precipitation from EOF (Empirical Orthogonal Function) analysis revealed ten wet years (1985, 1986, 1989, 1996, 1997, 1999, 2001, 2006, 2007, and 2015) and ten dry years (1981, 1983, 1987, 1990, 1992, 1994, 1995, 2005, 2011, and 2014). In general, the temporal trends analyses of seasonal (wet season) and annual precipitations both displayed slight decreasing slopes during the 37 years. The trend of precipitation per decade displayed an increase in precipitation during 1980s and 1990s, followed by a decrease in the 21st century. Furthermore, the analysis of the spatial and temporal variability and trends of rainfall showed that northern and central Malawi displayed a clearer variability than southern Malawi. Although the trends of most of the stations are not significant at 95% confidence level, the decreasing rates of rainfall in the last decade and the decreasing trends on wet season and annual scale detected by Mann–Kendall tests require closer monitoring of rainfall changes in the near future. The stations which exhibited significant trends (Naminjiwa and Dedza stations) also call for closer monitoring, since the area relies heavily on rain-fed agriculture for economic sustenance.

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Methylene blue inhibits lumefantrine-resistant Plasmodium berghei

The Journal of Infection in Developing Countries ◽

10.3855/jidc.7556 ◽

2016 ◽

Vol 10 (06) ◽

pp. 635-642 ◽

Cited By ~ 4

Author(s):

Victor Irungu Mwangi ◽

Ruth Mwende Mumo ◽

Daniel Muthui Kiboi ◽

Sabah Ahmed Omar ◽

Zipporah Waithera Ng'ang'a ◽

...

Keyword(s):

Methylene Blue ◽

Combination Therapy ◽

Large Scale ◽

Public Health Problem ◽

Drug Repurposing ◽

Sub Saharan Africa ◽

Major Public Health Problem ◽

Resistant Strains ◽

Sub Saharan ◽

Emergence Of Resistance

Introduction: Chemotherapy still is the most effective way to control malaria, a major public health problem in sub-Saharan Africa. The large-scale use of the combination therapy artemether-lumefantrine for malaria treatment in Africa predisposes lumefantrine to emergence of resistance. There is need to identify drugs that can be used as substitutes to lumefantrine for use in combination therapy. Methylene blue, a synthetic anti-methemoglobinemia drug, has been shown to contain antimalarial properties, making it a candidate for drug repurposing. The present study sought to determine antiplasmodial effects of methylene blue against lumefantrine- and pyrimethamine-resistant strains of P. berghei. Methodology: Activity of methylene blue was assessed using the classical four-day test on mice infected with lumefantrine-resistant and pyrimethamine-resistant P. berghei. A dose of 45 mg/kg/day was effective for testing ED90. Parasitemia and mice survival was determined. Results: At 45 mg/kg/day, methylene blue sustained significant parasite inhibition, over 99%, for at least 6 days post-treatment against lumefantrine-resistant and pyrimethamine-resistant P. berghei (p = 0.0086 and p = 0.0191, respectively). No serious adverse effects were observed. Conclusions: Our results indicate that methylene blue at a concentration of 45 mg/kg/day confers over 99% inhibition against lumefantrine- and pyrimethamine-resistant P. berghei for six days. This shows the potential use methylene blue in the development of antimalarials against lumefantrine- and pyrimethamine-resistant parasites.

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Evaluation of Vitamin D in Sickle Cell Anaemia Patients at Steady State

Annals of Clinical and Experimental Medicine ◽

10.47838/acem.26011977.127122020.asmeda.1.14 ◽

2020 ◽

Vol 1 (2) ◽

Author(s):

Umar Aminu Abdullah ◽

Mohammed Bashir AbdulRahman ◽

Bello Aminu ◽

Abubakar Umar Musa ◽

Isah Balarabe

Keyword(s):

Vitamin D ◽

Steady State ◽

Sickle Cell ◽

Sickle Cell Anaemia ◽

Public Health Problem ◽

Bone Fragility ◽

Sub Saharan Africa ◽

Major Public Health Problem ◽

The Mean ◽

Sub Saharan

Background: Sickle cell anaemia is a major public health problem in sub-Saharan Africa with high morbidities like bony alterations and bone fragility especially in those with vitamin D deficiency. There is paucity of research data on bone biomarkers in patients with sickle cell anaemia especially in Northern Nigeria. The aim of this study was to evaluate vitamin D in adult sickle cell anaemia patients at steady state. Materials and Methods: Seventy-seven patients with sickle cell anaemia and equal number of apparently healthy matched controls were recruited for the study. Various biochemical parameters of bone metabolism were measured. Data were analysed using IBM SPSS version 23.0. Results: The mean age of SCA adult patients and controls wer

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