Spread Of Measles Research Articles

Measles: a new danger for Ukraine's children! The need for an effective and timely vaccination prevention campaign for an insidious disease that comes from afar.

Measles, a highly contagious and dangerous disease that can cause disability or even death, remains endemic in Ukraine. This is a serious public health problem that absolutely needs to be monitored. Indeed, in the years 2017-2019, Ukraine was hit by a major measles epidemic, which caused serious problems for the population. The numerous efforts to contain the spread of measles in the country are now waning in the face of a devastating war, which has already lasted for over a year, and the COVID-19 pandemic, which has further complicated the general situation. In this paper, the authors highlight a very serious public health problem and invoke the immediate implementation of an effective vaccination policy. The percentages of measles vaccination coverage in Ukraine have decreased drastically since the beginning of the conflict (which began on February 24, 2022), and this is a source of concern regarding the possibility of a new major measles epidemic. Indeed, a measles epidemic at this time would have frightening consequences, given the conditions in which the Ukrainian population is now living. The United Nations estimates that at least 6 million people have been displaced within Ukraine as a result of the conflict, and this internal mass exodus has significantly affected vaccination coverage and adherence to vaccination schedules, despite the efforts of the Ukrainian health authorities. The ministry of health has prioritized vaccination programs with the help of the World Health Organization (WHO) and UNICEF, which are ensuring the free supply and delivery of vaccines through the deployment of mobile vaccination teams, even in areas where health facilities are not accessible. The main objective is to vaccinate as many people as possible in order to avoid a new epidemic, which could spread to the whole of Ukraine and also to other countries.

MODIFIKASI MODEL SEIR PADA PENYAKIT CAMPAK

The epidemic models Susceptible, Exposed, Infected and Recovered (SEIR) are used for the spread of diseases that have a latent period (incubation period) which one is measles disease. Latent periods are entered into the Exposed class. Measles itself after the incubation period will experience clinical symptoms consisting of three stages, which are prodromal stage, eruption stage and healing stage. Due to these clinical symptoms, the SEIR model can be modified by dividing the Infected class into two classes, which are Infected Prodromal class and Infected Eruption class. While the healing stage enters Recovered class. The spread of measles can be made into an epidemic model with five classes which are and . The purpose of this study is to explain the modification of the model, determine and analyze the model's local stability at the equilibrium point of the model and to interpret model simulations with multiple stability-eligible parameter values. The results obtained from this study are modification of model which is model. Based on model, two equilibrium points obtained which are disease-free equilibrium points and endemic equilibrium points, which are locally asymtotics stable with conditions. Model simulations are presented to support an explanation of model stability analysis based on stability-meeting parameters

Measles-Rubella Positivity Rate and Associated Factors in Pre-Mass and Post-Mass Vaccination Periods: Analysis of Uganda Routine Surveillance Laboratory Data

Toward 2019, Uganda experienced an extensive outbreak of measles and rubella. The Uganda National Expanded Programme on Immunization implemented a mass measles-rubella vaccination campaign aimed at halting the ongoing transmission. This study determined the changes in the disease burden thereafter. We conducted a retrospective cross-sectional study on measles-rubella positivity and its associated factors in Uganda using 1697 case-based surveillance data for 2019 and 2020 stratified into two dispensations: prevaccination and postvaccination campaigns. Statistical tests employed in STATA 15 included chi-square, Fisher’s exact, and binomial tests. Measles positivity rates in the period before and after the mass immunization campaign were 41.88% (95% CI: 39.30–44.51) and 37.96% (95% CI: 32.81–43.40), respectively. For rubella, the positivity rate in the precampaign season was 21.73% (95% CI: 19.61–23.99) and in the postvaccination season was 6.65% (95% CI: 4.36–10.00). Binomial tests indicated that postcampaign positivity rates were significantly lower than the precampaign rate for measles ( p = 0.003 ) and rubella ( p < 0.001 ). Generally, age (χ2 = 58.94, p = 0.001 /χ2 = 51.91, p < 0.001 ) and vaccination status (χ2 = 60.48, p = 0.001 /χ2 = 16.90, p = 0.001 ) were associated with the measles positivity rate in both pre/postcampaign periods. Rubella positivity rate was associated with vaccination status (χ2 = 32.97, p < 0.001 / p = 0.001 ) in both periods and age in the precampaign season ( p < 0.001 ). The measles-rubella mass campaign lessened rubella burden remarkably, but barely adequate change was observed in the extent of spread of measles. Children aged less than 9 months are at higher chances of testing positive amidst low vaccination levels among the eligible. The immunization programme must attain and maintain routine immunization coverage at 95% or more and roll out a second-dose measles-rubella vaccination to sustain the reduced disease burden.

Изучение напряженности поствакцинального иммунитета к кори и краснухе у студентов Республики Татарстан

The intensity of post-vaccination immunity to measles and rubella in students of medical educational institutions of the Republic of Tatarstan was studied. The study revealed the improved collective immunity to measles in this age group. At the same time, selective seromonitoring showed an excess of the values of seronegative individuals to the measles virus compared with the indicator of epidemiological well-being. In order to prevent the occurrence and spread of measles, rubella and to implement measures to eliminate endemic measles in the Russia, it is recommended to carry out additional revaccination of persons with no protective titers of antibodies to measles and rubella viruses, as well as to continue conducting research of collective immunity to this infection in this age group.

Measles in conflict-affected northern Syria: results from an ongoing outbreak surveillance program

BackgroundThe Syrian conflict has dramatically changed the public health landscape of Syria since its onset in March of 2011. Depleted resources, fractured health systems, and increased security risks have disrupted many routine services, including vaccinations, across several regions in Syria. Improving our understanding of infectious disease transmission in conflict-affected communities is imperative, particularly in the Syrian conflict. We utilize surveillance data from the Early Warning Alert and Response Network (EWARN) database managed by the Assistance Coordination Unit (ACU) to explore trends in the incidence of measles in conflict-affected northern Syria and analyze two consecutive epidemics in 2017 and 2018.MethodsWe conducted a retrospective time-series analysis of the incidence of clinically suspected cases of measles using EWARN data between January 2015 and June 2019. We compared regional and temporal trends to assess differences between geographic areas and across time.ResultsBetween January 2015 and June 2019, there were 30,241 clinically suspected cases of measles reported, compared to 3193 cases reported across the whole country in the decade leading up to the conflict. There were 960 regional events that met the measles outbreak threshold and significant differences in the medians of measles incidence across all years (p-value < 0.001) and in each pairwise comparison of years as well as across all geographic regions (p-value < 0.001). Although most governorates faced an elevated burden of cases in every year of the study, the measles epidemics of 2017 and 2018 in the governorates of Ar-Raqqa, Deir-Ez-Zor, and Idlib accounted for over 71% of the total suspected cases over the entire study period.ConclusionsThe 2017 and 2018 measles epidemics were the largest since Syria eliminated the disease in 1999. The regions most affected by these outbreaks were areas of intense conflict and displacement between 2014 and 2018, including districts in Ar-Raqqa, Deir-Ez-Zor, and Idlib. The spread of measles in northern Syria serves as an indicator of low immunization coverage and limited access to care and highlights the Syrian peoples’ vulnerability to infectious diseases and vaccine preventable diseases in the setting of the current conflict.

Measles in Zaporizhzhia: in the footsteps of the last epidemic

In 2017–2019 in Ukraine, including the Zaporizhzhia region, a strong rise in the incidence of measles was recorded. A retrospective analysis of the incidence in the Zaporizhzhia region during this outbreak allows us to identify the main problems in the system of epidemiological surveillance to predict future possible consequences.&#x0D; The aim of the work is to perform a comparative analysis of measles incidence in the Zaporizhzhia region with the data obtained in the period from 2015 to 2020 according to the epidemiological criteria.&#x0D; Materials and methods. The annual reports of 2015–2020 provided by the Department of Epidemiological Research of the Zaporizhzhia Regional Laboratory Center of the Ministry of Health of Ukraine were used as materials for the retrospective epidemiological analysis of measles incidence in Zaporizhzhia region. Statistical analysis of the data was carried out according to epidemiological characteristics: age distribution, the residence of patients in urban or rural areas. Commonly used statistical methods used in medicine were used to evaluate the obtained results.&#x0D; Results. It is concluded that in the Zaporizhzhia region during 2015 only 2 cases of measles were detected for children, and in 2016 no measles were registered in the region at all. In 2017–2019 1.433 measles patients were identified in the Zaporizhzhia region, of which 68 % were adults and 32 % were children. The lowest detection rate of measles was registered among rural residents. Insufficient vaccination coverage of the population has become a significant reason for the spread of measles among residents of the Zaporizhzhia region. In 2020 no cases of measles have been registered in the Zaporizhzhia region.&#x0D; Conclusions. The prevalence of incidence rate among adults attests to the fact that today measles can not be considered only a childhood disease. The deficiency of an immune layer, both among adults and children, contributed to the rapid spread of the disease. Mandatory vaccination of children and the introduction of additional vaccination of adults, optimizing the system of epidemiological surveillance for measles, including continuous monitoring of vaccination, is the main mechanism for combating this disease.

Air Passenger Travel and International Surveillance Data Predict Spatiotemporal Variation in Measles Importations to the United States.

Measles incidence in the United States has grown dramatically, as vaccination rates are declining and transmission internationally is on the rise. Because imported cases are necessary drivers of outbreaks in non-endemic settings, predicting measles outbreaks in the US depends on predicting imported cases. To assess the predictability of imported measles cases, we performed a regression of imported measles cases in the US against an inflow variable that combines air travel data with international measles surveillance data. To understand the contribution of each data type to these predictions, we repeated the regression analysis with alternative versions of the inflow variable that replaced each data type with averaged values and with versions of the inflow variable that used modeled inputs. We assessed the performance of these regression models using correlation, coverage probability, and area under the curve statistics, including with resampling and cross-validation. Our regression model had good predictive ability with respect to the presence or absence of imported cases in a given state in a given year (area under the curve of the receiver operating characteristic curve (AUC) = 0.78) and the magnitude of imported cases (Pearson correlation = 0.84). By comparing alternative versions of the inflow variable averaging over different inputs, we found that both air travel data and international surveillance data contribute to the model’s ability to predict numbers of imported cases and individually contribute to its ability to predict the presence or absence of imported cases. Predicted sources of imported measles cases varied considerably across years and US states, depending on which countries had high measles activity in a given year. Our results emphasize the importance of the relationship between global connectedness and the spread of measles. This study provides a framework for predicting and understanding imported case dynamics that could inform future studies and outbreak prevention efforts.

Measles outbreak investigation in Aweil East county, South Sudan.

During January 2018-June 2020, Aweil East confirmed five measles outbreaks. In March 2020, Aweil East reported twenty measles IgM+ cases. Before this outbreak, Aweil East had confirmed an outbreak in late November 2019. Even after conducting outbreak reactive vaccinations (ORV) in December 2019 and February 2020, measles spread was not interrupted. The nationally supported measles follow-up campaign (MFUC) conducted in late February 2020 was deferred in Aweil East because of the February ORV. We reviewed the measles data collected through passive and active surveillance. A matched case-control study was conducted to evaluate potential exposures. Face-to-face interviews with cases and controls using a semi-structured questionnaire were used to collect demographics, disease, and exposures related data. A total of 687 cases with eight deaths; attack and case fatality rate of 123/100,000 population and 1.16%, respectively. Among the cases, 51.8% were male, the median age was four years, and 59% of cases ≥9 months were unvaccinated. Eighty point six percent (80.6%) of cases reported after the February ORV were unvaccinated. The outbreak peaked in late March 2020. Unvaccinated persons had higher odds of getting measles (adjusted odds ratio (AOR)=8.569; 95% CI [1.41- 53.4], p=0.02). Non exposed persons had a lower odd of getting measles (AOR=0.114; 95% CI [0.02-0.61], p=0.011). During 2018-2019, the accumulated number of unvaccinated children (18,587) is more than a birth cohort of the county. Persistent low routine vaccination is the most critical driver of the measles outbreaks. Low-quality ORV and the intermediate population density are secondary drivers of the outbreaks.

Jewish Ethics Regarding Vaccination

AbstractIn recent years, more and more religious communities have been refusing to vaccinate their children, and in so doing are allowing diseases to spread. These communities justify resistance to vaccination on various religious grounds and make common cause with nonreligious communities who oppose vaccination for their own reasons. Today this situation is reflected primarily in the spread of measles, and vaccine hesitancy was identified by the World Health Organization as 1 of the top 10 global health threats of 2019. The present article presents the religious and ethical arguments for the obligation within Jewish tradition to vaccinate all children. Apart from the obligation on parents to vaccinate their own children, it includes the ethical arguments based on Judaism that call for parents to become organized and force schools to refuse to accept children who have not been vaccinated and demand vaccination of those who have not been inoculated.

Clinical and epidemiological characteristics of measles in the Astrakhan region in 2013–2019

In the first quarter of 2019, we registered 872 cases of measles in Russia, indicating a tense epidemic situation of this disease.Purpose.To determine clinical and epidemiological features of measles in the Astrakhan region (AR) from January 2013 to April 2019.Material and methods.We analyzed 663 cases of measles confirmed by enzyme immunoassay (293 children + 370 adults) in the AR from January 2013 to April 2019.Results.We found that in the age structure of measles incidence in AO prevail patients aged from 18 to 29 years old, unvaccinated or lacking vaccination information, unvaccinated children of 1-2 years old and children under 1 year old, not subject to measles vaccination. The main reasons for the lack of vaccination in children with measles under 17 years are medical withdrawal; and among adults – insufficient vaccination of people under 35 years and the absence of vaccination in people over 35 years. The main reasons for the incidence of measles among vaccinated children and adults is the violations of vaccination, inaccuracy of official measles vaccination data, which is confirmed by serological monitoring, indicating a decrease in the seropositive individuals among vaccinated persons. The presence of measles foci and the spread of infection can be explained by nosocomial outbreaks, spread of measles in the organized groups as a result of untimely identification and isolation of patients. Measles in children and adults of different age groups, both vaccinated and unvaccinated, occurred typically with a predominance of moderate form. The Filatov – Koplik symptom, despite its detection in only 54% of patients, remains the main sign for the diagnosis of measles in the catarrhal period of the disease, and pigmentation is a sign of the past illness.

Control of measles in a juvenile custodial setting in the wake of the recent US outbreak.

The recent US measles outbreak is the largest since 1992. It is just a matter of time before measles is introduced into a juvenile custodial setting. Are we prepared? Should we be prepared? This short article addresses steps institutional settings should take to prevent the spread of measles in a contained setting.

Air pollution and COVID-19: Is the connect worth its weight?

Primary route of transmission of SARS-CoV-2 among humans is droplets and direct contact. Airborne transmission of this virus is not established conclusively and so is the role of airborne particulate matter. This commentary examines the existing evidence about the role of particulate matter pollutants in SARS-CoV-2 transmission. PM2.5and other small particulate matter have been shown to carry viable virus particles in the air and incriminated in spread of measles and SARS coronavirus. Empirical evidence has been provided regarding role of air pollution in accelerated transmission of SARS-CoV-2 in Italy as well as Wuhan. Lockdown-related reduction in PM2.5levels in ambient air may have contributed to reduce transmission of SARS-CoV-2. High PM2.5levels in the past might have added to SARS-CoV-2 related mortality due to air pollution relate comorbidities. Post-lockdown increase in PM2.5levels may accelerate covid-19 transmission and can add to the burden of COVID-19 morbidity and mortality.

Основные результаты деятельности по улучшению состояния среды обитания и защите населения Тверской области от коревой инфекции

Background. The Russian and international community is concerned about the growing incidence of measles. This is typical for highly developed and developing countries and has an impact on the epidemic situation in Russia. Purpose of research: to study the main results of the activities carried out by the Rospotrebnadzor administration in the Tver region to improve the state of the environment and protect the population of the Tver region from measles infection. Material and methods. The results of implementation of measures to reduce the impact of risk factors of measles on the health of the population of the Tver region in 2017-2019 were analyzed. Analyzed indicators are: the incidence of measles per 100 thousand population; coverage of preventive vaccinations to prevent the spread of measles among controlled individuals (%); results of serological monitoring of the state of collective immunity against measles in indicator population groups by a passive hemagglutination reaction method with a protective titer of 1:10 or more (absolute number, %); comparative assessment of changes in indicators of the number of measles seronegative persons in indicator groups of the population (%). Results and discussion. A set of measures aimed at preventing the incidence of measles is being implemented in the Tver region. To do this, the population is immunized against measles every year. In 2017 38,881 people were vaccinated, in 2018 – 35,476 and in 2019 – 42,347 people. This led to the fact that in 2017 in the Tver region there were no cases of measles. In 2018 the incidence of measles was 0.23 per 100 thousand population (3 cases) and in 2019 – 0.86 per 100 thousand population (11 cases). All cases of measles were imported from foreign countries and various regions of Russia. The situation in the incidence of measles in the Tver region is much better than in the Russian Federation and the Central Federal District of Russia. This is facilitated by a consistently high vaccination coverage of adults and children. Vaccination coverage of children aged two years in 2019 amounted to 98.2%, at the age of 6 years – 94.4% and adults 18-35 years old – 99.7%. If during seromonitoring an increase in the specific gravity of seronegative persons was detected, then their vaccination was carried out as planned. Conclusion. The implementation on a regular basis by the Office of Rospotrebnadzor in the Tver region of a set of effective measures aimed at combating measles helps prevent the incidence of measles infection in the population of the Tver region.

Kontrol Optimal Upaya Pengobatan Penyakit Campak Menggunakan Model Endemi SIR

Measles is an acute highly contagious disease caused by Paramyxovirus. Measles is considered as a dangerous disease because it cause complications, brain and other organs damage, lifelong disability, paralysis and even death. In the previous studies, it was known that the spread of measles highly dependent on number of infected individuals so it is necessary to control measles through treatment. In this paper, we study about the application of the optimal control theory on the system of differential equations of the SIR endemic model. Determination of the optimal control is obtained through the application of the Pontryagin minimum principle. The main target in this paper is to find a unique optimal control where the optimal control can be described as an efficiency rate of treatment in individuals infected with measles to decrease the number of infected individuals.

Characteristics of the Epidemiological Situation of Measles in the Period of its Elimination in Republic of Moldova

Relevance Measles continues to be one of the priorities of health care worldwide, due to it high contagiosity, still widespread, severity of the disease and complications. A high degree of population migration contributes to the spread of infection, i.e. global measles virus circulation, clinical change and late diagnosis, inadequate immunization coverage. Aim. Analysis of measles incidence in the Republic of Moldova in 2000–2018. and features of the epidemic process. Materials and Methods. Statistics on measles incidence and immunization coverage in 2000–2018 were used. 340 cases of measles registered in the country in 2018 were subjected to a detailed analysis Results There is a decrease in measles vaccination coverage, in 2017–87.1%. In the same year, the coverage with the first revaccination at 6–7 years was 92.4% and the second at 14–15 years is 94.9%, which is not enough to maintain epidemiological well-being. There are territorial differences in vaccination coverage. In 2018, imported cases of measles were in 62.5% from Ukraine, 25.0% from Russia and 12.5% from Romania. There have been isolated measles cases (14), and epidemic foci or outbreaks (7), with from 2 to 252 cases of measles. The largest measles outbreak in 2018 was registered among those who rest in a religious camp unvaccinated against measles. The average age of the diseased is 14 years, and in outbreaks with a significant number of cases (9 and more) within 7.9–14.9 years. In the age structure of the diseased, children from 1 to 10 years old prevail (66.1%), children under one year old make up 8,2%, teenagers 17,5% and adults 8.2%. Only 11.0% received one dose of measles vaccine, and 3.6% of the relevant age groups received two doses of vaccine. The reason is the refusal of vaccination for religious motive. In 196 (57.6%) cases, the diagnosis was confirmed by laboratory methods, and in the remaining 144 (42.4%) by clinical and epidemiological data. Conclusions Measles remains a childhood infection, but cases of the disease occur among adolescents (17.5%) and adults (8.2%). The uneven of vaccination coverage throughout the country, the low level of responsibility of the population, the increased incidence of measles in neighboring countries, the high level of population migration are risk factors for the importation and spread of measles.

Spread of Measles in Europe and Implications for US Travelers.

From January 2018 to June 2018, World Health Organization (WHO) European Region countries reported >41 000 measles cases, including 37 deaths, a record high since the 1990s. Low vaccination coverage in previous years is the biggest contributing factor to the increase in cases. The Ukraine reported the majority of cases, but France, Georgia, Greece, Italy, the Russian Federation, and Serbia also reported high case counts. Europe is the most common travel destination worldwide and is widely perceived as being without substantial infectious disease risks. For this reason, travelers may not consider the relevance of a pretravel health consultation, including vaccination, in their predeparture plans. Measles is highly contagious, and the record number of measles cases in the WHO European Region not only puts unvaccinated and inadequately vaccinated travelers at risk but also increases the risk for nontraveling US residents who come into close contact with returned travelers who are ill. The US Centers for Disease Control and Prevention encourage US travelers to be aware of measles virus transmission in Europe and receive all recommended vaccinations, including for measles, before traveling abroad. Health care providers must maintain a high degree of suspicion for measles among travelers returning from Europe or people with close contact with international travelers who present with a febrile rash illness. The current WHO European Region outbreak should serve to remind health care providers to stay current with the epidemiology of highly transmissible diseases, such as measles, through media, WHO, and Centers for Disease Control and Prevention reports and encourage measles vaccination for international travelers.

Magnitude and Trends of Measles in North West of Tigray Region, Ethiopia - A Four-year Surveillance Data Analysis, 2012-2015

Introduction: Globally, measles is the leading cause of morbidity and mortality despite the availability of safe and effective vaccine. In Ethiopia, measles remains a disease of public health importance with an annual incidence of 12.5 to 18 per 100,000 populations. This study aimed at identifying the magnitude and trends of measles in the Northwest zone of Tigray region. Methods: We conducted a descriptive surveillance data analysis from 2012-2015 in the Northwest zone of Tigray region. We reviewed line list records and Health Information Management System reports. A suspected measles case was defined as any person with fever, rash, cough and either conjunctivitis or coryza. Laboratory confirmed cases had measles-specific IgM antibodies, and epidemiologically confirmed cases were those linked to a laboratory-confirmed case. We collected data by a standardized checklist, and analyzed it using Epi-info 7.1.5 and Microsoft Excel worksheet. We presented the analyzed data using frequencies, proportions, median and range. Results: We identified 757 measles cases with an annual incidence of 39 and 16 per 100,000 in 2012; 77 and 67 per 100,000 in 2015 in the 15-year-old respectively. Among these cases, 380(62%) were unvaccinated. Among <5 children, 27(3.6%) were <9-month infant ineligible for routine measles vaccination. Measles occurrence had a cyclical pattern from November to April, with high peaks from February to April. Conclusion: Children <5 years and adults aged ≥ 15 years were more affected in a cyclical occurrence of measles. Routine and supplementary immunization activities for more affected age groups including at-risk adults, and early preparedness before November may limit occurrence and spread of measles.

Optimal Control Problem of Vacination for The Spread of Measles Diseases Model

Measles is a disease in humans that is very contagious. Before the vaccine was known, the incidence of measles was very high, even the measles mortality rate reached 2.6 million every year. With the introduction of vaccines, the mortality rate in 2000-2016 can be reduced to 20.4 million deaths. Therefore, vaccination programs are very useful in reducing the incidence of measles. Unfortunately, we cannot know the optimal conditions for administering vaccines. The study of optimal control analysis of vaccination is needed in optimizing the prevention of the spread of measles. In this paper, a mathematical model which is a third-order differential equation system is constructed based on characteristic information on measles. The existence and locally stability of the equilibrium point are analyzed here. In addition, optimal control of the vaccination program also occurred. The results of our analysis suggest that the incidence of measles can decrease as the effectiveness of vaccination increases. But the effectiveness of vaccination is directly proportional to the costs incurred. If the cost incurred for the vaccination program more significant, the incidence of measles will decrease.

Measles outbreak risk in Pakistan: exploring the potential of combining vaccination coverage and incidence data with novel data-streams to strengthen control.

Although measles incidence has reached historic lows in many parts of the world, the disease still causes substantial morbidity globally. Even where control programs have succeeded in driving measles locally extinct, unless vaccination coverage is maintained at extremely high levels, susceptible numbers may increase sufficiently to spark large outbreaks. Human mobility will drive potentially infectious contacts and interact with the landscape of susceptibility to determine the pattern of measles outbreaks. These interactions have proved difficult to characterise empirically. We explore the degree to which new sources of data combined with existing public health data can be used to evaluate the landscape of immunity and the role of spatial movement for measles introductions by retrospectively evaluating our ability to predict measles outbreaks in vaccinated populations. Using inferred spatial patterns of accumulation of susceptible individuals and travel data, we predicted the timing of epidemics in each district of Pakistan during a large measles outbreak in 2012-2013 with over 30 000 reported cases. We combined these data with mobility data extracted from over 40 million mobile phone subscribers during the same time frame in the country to quantify the role of connectivity in the spread of measles. We investigate how different approaches could contribute to targeting vaccination efforts to reach districts before outbreaks started. While some prediction was possible, accuracy was low and we discuss key uncertainties linked to existing data streams that impede such inference and detail what data might be necessary to robustly infer timing of epidemics.

Factors contributing to measles transmission during an outbreak in Kamwenge District, Western Uganda, April to August 2015

BackgroundIn April 2015, Kamwenge District, western Uganda reported a measles outbreak. We investigated the outbreak to identify potential exposures that facilitated measles transmission, assess vaccine effectiveness (VE) and vaccination coverage (VC), and recommend prevention and control measures.MethodsFor this investigation, a probable case was defined as onset of fever and generalized maculopapular rash, plus ≥1 of the following symptoms: Coryza, conjunctivitis, or cough. A confirmed case was defined as a probable case plus identification of measles-specific IgM in serum. For case-finding, we reviewed patients’ medical records and conducted in-home patient examination. In a case-control study, we compared exposures of case-patients and controls matched by age and village of residence. For children aged 9 m-5y, we estimated VC using the percent of children among the controls who had been vaccinated against measles, and calculated VE using the formula, VE = 1 - ORM-H, where ORM-H was the Mantel-Haenszel odds ratio associated with having a measles vaccination history.ResultsWe identified 213 probable cases with onset between April and August, 2015. Of 23 blood specimens collected, 78% were positive for measles-specific IgM. Measles attack rate was highest in the youngest age-group, 0-5y (13/10,000), and decreased as age increased. The epidemic curve indicated sustained propagation in the community. Of the 50 case-patients and 200 controls, 42% of case-patients and 12% of controls visited health centers during their likely exposure period (ORM-H = 6.1; 95% CI = 2.7–14). Among children aged 9 m-5y, VE was estimated at 70% (95% CI: 24–88%), and VC at 75% (95% CI: 67–83%). Excessive crowding was observed at all health centers; no patient triage-system existed.ConclusionsThe spread of measles during this outbreak was facilitated by patient mixing at crowded health centers, suboptimal VE and inadequate VC. We recommended emergency immunization campaign targeting children <5y in the affected sub-counties, as well as triaging and isolation of febrile or rash patients visiting health centers.