PO 8505 LEISHMANIASIS IN ANGOLA – AN EMERGING DISEASE?

BackgroundPoverty, lack of resources, inadequate treatments and control programmes exacerbate the impact of infectious diseases in the developing world. Leishmaniasis is a vector-borne disease that is among the ten major neglected tropical diseases. Although endemic in more than 90 countries, the ones most affected, representing over 90% of new cases, are Bangladesh, Brazil, Ethiopia, India, Kenya, Nepal, and Sudan. In Africa south of the equator, the impact of leishmaniasis is much lower. In several countries, like Angola, little is known about this infectious neglected disease. In the 1970s, a group of Portuguese researchers described three cases of cutaneous leishmaniasis in children from Huambo district and in the 1990s visceral leishmaniasis was diagnosed in an African patient. More recently a canine survey in Luanda revealed two Leishmania-infected dogs.After some suspected cases of human cutaneous leishmaniasis in Huambo region in 2017, the Angola health authorities and the Instituto de Higiene e Medicina Tropical (IHMT), Lisbon, Portugal, established a collaboration to analyse samples from some suspected cases.MethodsThree paraffin-embedded human skin samples from dermatological lesions were sent to IHMT for molecular analysis. After DNA extraction, PCR was performed by using four protocols with different molecular markers.ResultsOne PCR protocol using a nested approach was positive in two of the samples. Sequencing analysis confirmed Leishmania sp. DNA.ConclusionThis was the first time that suspected human cutaneous samples were screened for leishmaniasis by molecular methods with detection of Leishmania sp. DNA. These preliminary studies highlight the need for higher awareness of health professionals for leishmaniasis clinical forms, to recognise risk factors and the epidemiological features of leishmaniasis in the Huambo province. It would be relevant to perform further epidemiological studies to confirm if this vector-borne disease could be emergent in this country.

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Modelling the impact of COVID-19-related control programme interruptions on progress towards the WHO 2030 target for soil-transmitted helminths

Transactions of the Royal Society of Tropical Medicine and Hygiene ◽

10.1093/trstmh/traa156 ◽

2020 ◽

Cited By ~ 1

Author(s):

Veronica Malizia ◽

Federica Giardina ◽

Carolin Vegvari ◽

Sumali Bajaj ◽

Kevin McRae-McKee ◽

...

Keyword(s):

Neglected Tropical Diseases ◽

Control Programme ◽

Mitigation Strategy ◽

Mitigation Strategies ◽

Preventive Chemotherapy ◽

Soil Transmitted Helminths ◽

Individual Based Models ◽

Control Programmes ◽

Catch Up ◽

The Impact

Abstract Background On 1 April 2020, the WHO recommended an interruption of all activities for the control of neglected tropical diseases, including soil-transmitted helminths (STH), in response to the COVID-19 pandemic. This paper investigates the impact of this disruption on the progress towards the WHO 2030 target for STH. Methods We used two stochastic individual-based models to simulate the impact of missing one or more preventive chemotherapy (PC) rounds in different endemicity settings. We also investigated the extent to which this impact can be lessened by mitigation strategies, such as semiannual or community-wide PC. Results Both models show that without a mitigation strategy, control programmes will catch up by 2030, assuming that coverage is maintained. The catch-up time can be up to 4.5 y after the start of the interruption. Mitigation strategies may reduce this time by up to 2 y and increase the probability of achieving the 2030 target. Conclusions Although a PC interruption will only temporarily impact the progress towards the WHO 2030 target, programmes are encouraged to restart as soon as possible to minimise the impact on morbidity. The implementation of suitable mitigation strategies can turn the interruption into an opportunity to accelerate progress towards reaching the target.

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Cutaneous leishmaniasis a neglected tropical disease: community knowledge, attitude and practices in an endemic area, Northwest Ethiopia

BMC Infectious Diseases ◽

10.1186/s12879-019-4506-1 ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 4

Author(s):

Helina Fikre Tamiru ◽

Yohana James Mashalla ◽

Rezika Mohammed ◽

Gloria Thupayagale Tshweneagae

Keyword(s):

Cutaneous Leishmaniasis ◽

Rural Areas ◽

Neglected Tropical Diseases ◽

Numerical Data ◽

Northwest Ethiopia ◽

Duration Of Treatment ◽

Cross Sectional ◽

Awareness Campaigns ◽

Modern Treatment ◽

The Impact

Abstract Background Cutaneous leishmaniasis is one of the neglected tropical diseases in the Ethiopian highlands and studies on assessment of knowledge, attitude and practice of the community in endemic areas are scanty. The study aimed to assess the knowledge, attitude towards cutaneous leishmaniasis and treatment seeking practices in people living in the endemic highlands areas in the Northwest, Ethiopia and to provide evidence-based information to guide development of appropriate interventions to reduce the impact of cutaneous leishmaniasis on communities. Methods Quantitative cross-sectional study was conducted in cutaneous leishmaniasis endemic districts (woredas) using a semi structured questionnaire. Households were randomly selected according to probability proportional to size of households in each enumeration area. Systematic random sampling of eligible households was based on the number of households recorded during listing of households. Descriptive statistics was used to describe numerical data, organise and summarise the data in a manner that gave meaning to the numerical form. Frequency tables were used to show descriptive analysis and regression analysis was used to determine correlation between variables. Results Majority of respondents 321(78.7%) lived in rural areas, age ranged between 18 and 85 years and most were farmers. Illiteracy was high (47.6%) among respondents and majority 358(87.8%) had seen patients with CL. Less than quarter (21.6%) had heard about sand flies and knowledge on the peak transmission period was low (46.3%). About 192 (47.1%) of the respondents indicated disfiguring lesions were the major clinical presentations, less than half 55(27.5%) of urban residents believed CL was treatable compared to 145(72.5%) of rural residents (P < 0.001). Traditional medicines were indicated as best treatment option by 209(51.2%) compared to 114(27.9%) for modern treatment. Major factors influencing treatment options included accessibility to treatment facilities, distance and short duration of treatment. Participants expressed negative experiential attitude and perceived control towards modern treatment because of inaccessibility and distance from where modern treatment is provided. Conclusion Priority should be given to primary prevention and appropriate awareness campaigns on lesion recognition. Information on modern treatment should be intensified.

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Stability Analysis and Optimal Control of a Vector-Borne Disease with Nonlinear Incidence

Discrete Dynamics in Nature and Society ◽

10.1155/2012/595487 ◽

2012 ◽

Vol 2012 ◽

pp. 1-21 ◽

Cited By ~ 17

Author(s):

Muhammad Ozair ◽

Abid Ali Lashari ◽

Il Hyo Jung ◽

Kazeem Oare Okosun

Keyword(s):

Optimal Control ◽

Sensitivity Analysis ◽

Control Measures ◽

Basic Reproductive Number ◽

Control Technique ◽

Global Dynamics ◽

Nonlinear Incidence ◽

Vector Borne Disease ◽

Vector Borne ◽

The Impact

The paper considers a model for the transmission dynamics of a vector-borne disease with nonlinear incidence rate. It is proved that the global dynamics of the disease are completely determined by the basic reproduction number. In order to assess the effectiveness of disease control measures, the sensitivity analysis of the basic reproductive numberR0and the endemic proportions with respect to epidemiological and demographic parameters are provided. From the results of the sensitivity analysis, the model is modified to assess the impact of three control measures; the preventive control to minimize vector human contacts, the treatment control to the infected human, and the insecticide control to the vector. Analytically the existence of the optimal control is established by the use of an optimal control technique and numerically it is solved by an iterative method. Numerical simulations and optimal analysis of the model show that restricted and proper use of control measures might considerably decrease the number of infected humans in a viable way.

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The impact of industrial activities on vector-borne disease transmission

Acta Tropica ◽

10.1016/j.actatropica.2018.08.033 ◽

2018 ◽

Vol 188 ◽

pp. 142-151 ◽

Cited By ~ 3

Author(s):

Robert T. Jones ◽

Lucy S. Tusting ◽

Hugh M.P. Smith ◽

Sylvester Segbaya ◽

Michael B. Macdonald ◽

...

Keyword(s):

Disease Transmission ◽

Industrial Activities ◽

Vector Borne Disease ◽

Vector Borne ◽

The Impact

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Assessing the potential impact of vector-borne disease transmission following heavy rainfall events: a mathematical framework

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2018.0272 ◽

2019 ◽

Vol 374 (1775) ◽

pp. 20180272 ◽

Cited By ~ 4

Author(s):

G. Chowell ◽

K. Mizumoto ◽

J. M. Banda ◽

S. Poccia ◽

C. Perrings

Keyword(s):

Disease Transmission ◽

Disease Outbreaks ◽

Theme Issue ◽

Rainfall Events ◽

Transmission Season ◽

Vector Borne Disease ◽

Infectious Disease Outbreaks ◽

Vector Borne ◽

The Impact ◽

Heavy Rainfall Events

Predicting the impact of natural disasters such as hurricanes on the transmission dynamics of infectious diseases poses significant challenges. In this paper, we put forward a simple modelling framework to investigate the impact of heavy rainfall events (HREs) on mosquito-borne disease transmission in temperate areas of the world such as the southern coastal areas of the USA. In particular, we explore the impact of the timing of HREs relative to the transmission season via analyses that test the sensitivity of HRE-induced epidemics to variation in the effects of rainfall on the dynamics of mosquito breeding capacity, and the intensity and temporal profile of human population displacement patterns. The recent Hurricane Harvey in Texas motivates the simulations reported. Overall, we find that the impact of vector-borne disease transmission is likely to be greater the earlier the HREs occur in the transmission season. Simulations based on data for Hurricane Harvey suggest that the limited impact it had on vector-borne disease transmission was in part because of when it occurred (late August) relative to the local transmission season, and in part because of the mitigating effect of the displacement of people. We also highlight key data gaps related to models of vector-borne disease transmission in the context of natural disasters. This article is part of the theme issue ‘Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes’. This issue is linked with the subsequent theme issue ‘Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control’.

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Resurgence of Vector-Borne and Vaccine-Preventable Diseases in Venezuela in Times of a Complex Humanitarian Health Crisis: A Regional Menace

Prehospital and Disaster Medicine ◽

10.1017/s1049023x1900030x ◽

2019 ◽

Vol 34 (s1) ◽

pp. s5-s6

Author(s):

Adriana Tami ◽

Maria Eugenia Grillet ◽

Alberto Paniz-Mondolfi ◽

José Oletta ◽

Martin S Llewellyn ◽

...

Keyword(s):

Essential Medicines ◽

Malaria Surveillance ◽

Complex Situation ◽

Health Crisis ◽

Vaccine Preventable Diseases ◽

Health Authorities ◽

National Immunization ◽

Healthcare Crisis ◽

Vector Borne ◽

The Impact

Introduction:Venezuela has plunged into a humanitarian, economic, and health crisis of extraordinary proportions. This complex situation is derived from dismantling of structures at the institutional, legal, political, social, and economic level affecting the life and wellbeing of the entire population.Aim:This study aims to assess the impact of Venezuela’s healthcare crisis on vector-borne and vaccine-preventable diseases and the spillover to neighboring countries.Methods:Since October 2014, there is a paucity of official epidemiological information in Venezuela. An active search of published and unpublished data was performed. Venezuela and Latin America data were sourced from PAHO Malaria Surveillance and from Observatorio Venezolano de la Salud. Brazil and Colombian data were accessed via their respective Ministries of Health.Results:Economic and political mismanagement have precipitated a general collapse of Venezuela’s health system with hyperinflation rates above 45,000%, people impoverishment, and long-term shortages of essential medicines and medical supplies. In this context, the rapid resurgence of previously well-controlled diseases, such as vaccine-preventable (measles, diphtheria) and arthropod-borne (malaria, dengue) diseases has turned them into epidemics of unprecedented magnitudes. Between 2000-2015 Venezuela witnessed a 365% increase in malaria cases followed by a 68% increase (319,765 cases) in late 2017. The latest figures have surpassed 600,000 malaria cases with a prediction to reach 1 million by the end of 2018. Measles and diphtheria have recently re-emerged after a progressive interruption of the national immunization program, with vulnerable indigenous population being particularly affected. In response to Venezuela’s rapidly decaying situation, a massive population exodus is ongoing towards neighboring countries causing a spillover of diseases.Discussion:Action to halt the spread of vaccine-preventable diseases within Venezuela is a matter of urgency for the country and the region. Global and hemispheric health authorities should urge the Venezuelan government to allow establishing a humanitarian channel to bring relief.

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The impact of global environmental change on vector-borne disease risk: a modelling study

The Lancet Planetary Health ◽

10.1016/s2542-5196(18)30086-x ◽

2018 ◽

Vol 2 ◽

pp. S1

Author(s):

Rachel Lowe

Keyword(s):

Environmental Change ◽

Disease Risk ◽

Global Environmental Change ◽

Vector Borne Disease ◽

Global Environmental ◽

Vector Borne ◽

The Impact ◽

Modelling Study

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Climate Cycles and Forecasts of Cutaneous Leishmaniasis, a Nonstationary Vector-Borne Disease

PLoS Medicine ◽

10.1371/journal.pmed.0030295 ◽

2006 ◽

Vol 3 (8) ◽

pp. e295 ◽

Cited By ~ 129

Author(s):

Luis Fernando Chaves ◽

Mercedes Pascual

Keyword(s):

Cutaneous Leishmaniasis ◽

Vector Borne Disease ◽

Climate Cycles ◽

Vector Borne

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Modeling the 2013 Zika Outbreak in French Polynesia: Intervention Strategies

Applied System Innovation ◽

10.3390/asi1030031 ◽

2018 ◽

Vol 1 (3) ◽

pp. 31 ◽

Cited By ~ 1

Author(s):

Harsha Gwalani ◽

Faris Hawamdeh ◽

Armin Mikler ◽

Katherine Xiong

Keyword(s):

French Polynesia ◽

Disease Outbreak ◽

Intervention Strategies ◽

International Travel ◽

Mosquito Population ◽

Travel Patterns ◽

Transit Network ◽

Vector Borne Disease ◽

Vector Borne ◽

The Impact

The ongoing Zika virus (ZIKV) in the Americas has been a serious public health emergency since 2015. Since Zika is a vector-borne disease, the size of the vector population in the affected area plays a key role in controlling the scale of the outbreak. The primary vectors for Zika, the Aedes Agypti and Aedes Albopictus species of mosquitoes, are highly sensitive to climatic conditions for survival and reproduction. Additionally, increased international travel over the years has caused the disease outbreak to turn into a pandemic affecting five continents. The mosquito population and the human travel patterns are the two main driving forces affecting the persistence and resurgence of Zika and other vector-borne diseases. This paper presents an enhanced dynamic model that simulates the 2013–2014 French Polynesia Zika outbreak incorporating the temperature dependent mosquito ecology and the local transit network (flights and ferries). The study highlights the importance of human travel patterns and mosquito population dynamics in a disease outbreak. The results predict that more than 85% of the population was infected by the end of the outbreak and it lasted for more than five months across the islands. The basic reproduction number ( R 0 ) for the outbreak is also calculated using the next-generation-matrix for validation purposes. Additionally, this study is focused on measuring the impact of intervention strategies like reducing the mosquito population, preventing mosquito bites and imposing travel bans. French Polynesia was chosen as the region of interest for the study because of available demographic, climate and transit data. Additionally, results from similar studies for the region are available for validation and comparison. However, the proposed system can be used to study the transmission dynamics of any vector-borne disease in any geographic region by altering the climatic and demographic data, and the transit network.

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