Epidemiologic Characteristics of Imported and Domestic Chikungunya Cases in Taiwan: A 13-Year Retrospective Study

Emerging Infectious Diseases and the Eye: Ophthalmic Manifestations, Pathogenesis, and One Health Perspectives

Infectious diseases may lead to ocular complications including uveitis, an ocular inflammatory condition with potentially sight-threatening sequelae, and conjunctivitis, inflammation of the conjunctiva. Emerging infectious pathogens with known ocular findings include Ebola virus, Zika virus, Avian influenza virus, Nipah virus, severe acute respiratory syndrome coronaviruses, and Dengue virus. Re-emerging pathogens with ocular findings include Toxoplasma gondii and Plasmodium species that lead to malaria. The concept of One Health involves a collaborative and interdisciplinary approach to achieve optimal health outcomes by combining human, animal, and environmental health factors. This approach examines the interconnected and often complex human-pathogen-intermediate host interactions in infectious diseases that may also result in ocular disease, including uveitis and conjunctivitis. Through a comprehensive review of the literature, we review the ophthalmic findings of emerging infectious diseases, pathogenesis, and One Health perspectives that provide further insight into the disease state. While eye care providers and vision researchers may often focus on key local aspects of disease process and management, additional perspective on host-pathogen-reservoir life cycles and transmission considerations, including environmental factors, may offer greater insight to improve outcomes for affected individuals and stakeholders.

Chikungunya in Zhejiang Province, Southeast China

Background

Chikungunya is emerging and reemerging word-widely in the past decades. It is non-endemic in Zhejiang Province, Southeast China. Aedes albopictus, one of major vectors of chikungunya, is widely-distribution in Zhejiang, and autochthonous transmission is possible after introducing chikungunya virus.

Methods

Retrospectively collected the epidemiological, clinical and genetic data of chikungunya and conducted the descriptive analysis and gene sequence analysis.

Results

From 2008 to 2022, 29 chikungunya cases, including 26 overseas imported and 3 local cases, were reported and no cases died of chikungunya. More than half of the imported cases (53.85%) were from Southeast Asia. Seasonal peak of the imported cases was noted between August and September, and 42.31% cases onset in those 2 months. Eight prefecture-level cities and 16 counties reported cases during the study period, with Jinghua (27.59%) and Hangzhou (24.14%) reporting the largest number of cases. The 3 local cases were all reported in Qujiang, Quzhou in 2017. For imported cases, the male-female gender ratio was 2.71:1, 20-30 years old cases (46.15%) and commercial service (42.31%) accounted for the highest proportion. Clinically, fever (100%), fatigue (94.44%), arthralgia (79.17%), headache (71.43%) and erythra (65.22%) were the most common reported symptoms. Eight whole-genome sequences were obtained and belonged to East/Central/South African (ECSA) or Asian genotype.

Conclusions

With the change of immigration policy, the surveillance of chikungunya should be strengthened and the ability of the case discovery and diagnosis should be improved in Zhejiang in the post-COVID-19 era.

The epidemiology of Aedes-borne arboviral diseases in Zhejiang, Southeast China: a 20 years population-based surveillance study

Objective

Aedes-borne arboviral diseases were important public health problems in Zhejiang before the coronavirus disease 2019 (COVID-19) pandemic. This study was conducted to investigate the characteristics and change of the epidemiology of Aedes-borne arboviral diseases in the province.

Methods

Descriptive analyses were conducted to summarize the epidemiology of Aedes-borne arboviral diseases during 2003-2022.

Results

A total of 3,125 cases, including 1,968 indigenous cases, were reported during 2003-2022. Approximately three-quarters of imported cases were infected from Southeast Asia. The number of annual imported cases increased during 2013-2019 (R2 = 0.801, p = 0.004) and peaked in 2019. When compared with 2003-2012, all prefecture-level cities witnessed an increase in the annual mean incidence of imported cases in 2013-2019 (0.11-0.42 per 100,000 population vs. 0-0.05 per 100,000 population) but a drastic decrease during 2020-2022 (0-0.03 per 100,000 population). The change in geographical distribution was similar, with 33/91 counties during 2003-2012, 86/91 during 2013-2019, and 14/91 during 2020-2022. The annual mean incidence of indigenous cases in 2013-2019 was 7.79 times that in 2003-2012 (0.44 vs. 0.06 per 100,000 population). No indigenous cases were reported between 2020-2022. Geographical extension of indigenous cases was also noted before 2020-from two counties during 2003-2012 to 44 during 2013-2019.

Conclusion

Dengue, chikungunya fever, zika disease, and yellow fever are not endemic in Zhejiang but will be important public health problems for the province in the post-COVID-19 era.

Chikungunya: An Emerging Public Health Concern

Purpose of Review

The worldwide spread of chikungunya over the past two decades calls for greater knowledge and awareness of the virus, its route of transmission, methods of diagnosis, and the use of available treatment and prevention measures.

Recent Findings

Chikungunya virus infection, an Aedes mosquito-borne febrile disease, has spread from Africa and Asia to Europe and the Americas and from the tropics and subtropics to temperate regions. International travel is a pivotal influence in the emergence of chikungunya as a global public health threat, as evidenced by a growing number of published reports on travel-related chikungunya infections. The striking features of chikungunya are arthralgia and arthritis, and the disease is often mistaken for dengue. Although mortality is low, morbidity can be profound and persistent. Current treatment for chikungunya is supportive; chikungunya vaccines and therapeutics are in development. Travelers planning to visit areas where the mosquito vectors are present should be advised on preventive measures.

Summary

Chikungunya is an emerging disease in the Americas. Frequent travel, the presence of at least two competent mosquito species, and a largely naïve human population in the Western Hemisphere create a setting conducive to future outbreaks. Awareness of the disease and its manifestations is critical to effectively and safely manage and limit its impact. Vaccines in late-stage clinical trials offer a new pathway to prevention.

Epidemiological features and risk factors for measles and rubella in Taiwan during 2011 to 2020

The risk of geographic transmission of infectious diseases due to air travel varies greatly. Our aim is to survey empirical data that provide a retrospective historical perspective on measles and rubella. This study used the open data website provided by the Taiwan Centers for Disease Control (TCDC) to extract the reported numbers of measles and rubella case between 2011 and 2020. There were 306 cases of measles and 135 cases of rubella. The incidence of measles and rubella per million population were 0 to 6.0 and 0 to 2.6, respectively. There was a gradual increase in the numbers of cases in those aged 20-39 years, and distinct duration patterns. It indicated that the risk of contracting rubella has significantly decreased in the last 5 years. Measles cases aged 20 to 39 years accounted for 72.5% of all cases. Rubella cases aged 20 to 39 years accounted for 59.3% of all cases. The male and residency in the Taipei metropolitan area or northern area were identified as potential risk factors for measles and rubella. Coverage with the first dose of the measles, mumps and rubella (MMR) vaccine in Taiwan increased from 97.31% to 98.86%, and the uptake rate of the second dose of the MMR vaccine increased from 95.73% to 98.39% between 2010 and 2020. Furthermore, the numbers of imported cases of measles (n = 0) and rubella (n = 0) reported during the coronavirus disease 2019 (COVID-19) pandemic were lower than those from 2011 to 2019. Measles and rubella cases were imported most frequently from Cambodia and Vietnam. This study represents the first report of confirmed cases of acquired measles and rubella from surveillance data of the TCDC between 2011 and 2020, also demonstrates that the numbers of cases of measles and rubella significantly decreased in Taiwan during the COVID-19 pandemic.

Risk Factors Associated with Passengers with Imported Dengue Fever at International Airports in Taiwan

Dengue fever (DF) is a mosquito-borne disease prevalent in the tropics (e.g., sub-Saharan Africa, Asia, and Central and South America) and a common cause of febrile illness in travelers. The high incidence of imported DF in Taiwan has led to a domestic outbreak. This study explored the risk factors associated with individuals given diagnoses of imported DF at international airports in Taiwan. The results may serve as a reference for DF prevention. In this retrospective study, data from the symptom notification system database of the Taiwan Centers for Disease Control (TCDC) were used. These data concerned travelers who returned to Taiwan from DF-endemic areas with suspected DF symptoms. The epidemiological characteristics of the cases were analyzed, and 28 variables related to DF infection were included in the multivariate logistic regression analysis. In 2018-2019, there were 8656 cases (451 positive and 8205 negative cases). The results revealed DF symptoms and a 16-30-day stay in endemic areas to be independent risk factors and the presence of three respiratory symptoms and <10 days of short-term travel to be protective factors. These results may enable the accurate assessment of symptoms in travelers with DF as well as the risk factors associated with imported DF, lowering the risk of indigenous DF outbreaks caused by imported DF.

Epidemiological features of domestic and imported cases with COVID-19 between January 2020 and March 2021 in Taiwan

Coronavirus disease-2019 (COVID-19) is a global pandemic affecting numerous countries around the world. This study elaborates Taiwan's epidemiological characteristics from the 2020 to 2021 COVID-19 pandemic from human, temporal, and geographical dimensions. Big data for cases were obtained from a public database from the Taiwan Centers for Disease Control (CDC) in April 2021. The data were analyzed and used to compare differences, correlations, and trends for human, temporal, and geographical characteristics for imported and domestic COVID-19 cases. During the study period, 1030 cases were confirmed and the mortality rate of 1.0%. The epidemiological features indicated that most cases (953/1030, 92.5%) were imported. A comparison of the domestic confirmed and imported cases revealed the following findings: No significant difference of COVID-19 between males and females for sex was observed; For age, the risk of domestic transmission was significantly lower for 20 to 29 years old, higher for 50 to 59 years old, and >60 years old with odds ratios (ORs) (P value < .05) of 0.36, 3.37, and 2.50, respectively; For the month of infection, the ORs (P value < .05) of domestic confirmed cases during January and February 2020 were 22.428; and in terms of area of residence, the ORs (P value < .05) for domestic confirmed cases in northern and southern Taiwan were 4.473 and 0.033, respectively. Thus, the increase in domestic cases may have been caused by international travelers transmitting the virus in March 2020 and December 2020, respectively. Taiwan has been implementing effective screening and quarantine measures at airports. Moreover, Taiwan has implemented and maintained stringent interventions such as large-scale epidemiological investigation, rapid diagnosis, wearing masks, washing hands frequently, safe social distancing, and prompt clinical classifications for severe patients who were given appropriate medical measures. This is the first report comparing imported and domestic cases of COVID-19 from surveillance data from the Taiwan Centers for Disease Control during January 2020 and March 2021. It illustrates that individuals infected during overseas travel are the main risk factors for the spread of COVID-19 in Taiwan. The study also highlights the importance of longitudinal and geographically extended studies in understanding the implications of COVID-19 transmission for Taiwan's population.

Incidence and Risk Factors for Notifiable Typhoid and Paratyphoid in Taiwan during the Period 2011-2020

The risk of the geographic transmission of emerging infectious diseases through air travel varies greatly. In this study, we collected data on cases of food-borne diseases between the years 2011 and 2020 in Taiwan to access the epidemiological features, differences, and trends in domestic and imported cases of typhoid and paratyphoid in terms of patient sex, age, month of confirmation, and area of residence. In this study, we made use of the open data website provided by Taiwan’s Centers for Disease Control (TCDC) to extract the reported numbers of cases of typhoid and paratyphoid between January and December from 2011 to 2020 for comparison. Univariate analysis was performed using the Chi-square test for categorical variables. Fisher’s exact test was performed if an expected frequency was less than 5. A total of 226 typhoid cases and 61 paratyphoid cases were analyzed from the database. The incidences of typhoid and paratyphoid per million of the population were 0.42–2.11 and 0–0.39, respectively. There was a significant difference in the incidence of the diseases between the age groups (p = 0.019), with a gradual increase in the 20–40 years group. A distinct seasonal (between fall and spring) variation was also observed (p = 0.012). There were 34 cases of children with typhoid in the period 2011–2015 and 12 cases of children with typhoid in the period 2016–2020. During these periods, there were two cases of paratyphoid. This study indicated that the risk of children suffering from typhoid has been significantly reduced in the last five years. Furthermore, we found that more women have acquired typhoid and paratyphoid than men, and that living in the Taipei metropolitan area and the northern area was a potential risk factor. Furthermore, the number of imported cases of typhoid (n = 3) and paratyphoid (n = 0) reported during the COVID-19 pandemic was lower than that reported for the same disease from 2011 to 2020. More typhoid and paratyphoid cases were imported from Indonesia, India, Myanmar, and Cambodia. This study represents the first report on confirmed cases of acquired typhoid and paratyphoid from surveillance data from Taiwan’s CDC for the period 2011–2020. This study also demonstrates that the cases of typhoid and paratyphoid decreased in Taiwan during the COVID pandemic. Big data were used in this study, which may inform future surveillance and research efforts in Taiwan.

An Increased Risk of School-Aged Children with Viral Infection among Diarrhea Clusters in Taiwan during 2011-2019

Acute diarrhea is mainly caused by norovirus and rotavirus. Numerous factors modify the risk of diarrhea cluster infections and outbreaks. The purpose of this study was to explore the epidemiological characteristics, differences, and trends in the distribution of viral and bacterial pathogens that cause diarrhea cluster events as well as the public places where diarrhea cluster events took place in Taiwan from 2011 to 2019. We examined publicly available, annual summary data on 2865 diarrhea clusters confirmed by the Taiwan Centers for Disease Control (CDC) from 2011 to 2019. There were statistically significant differences (p < 0.001) in event numbers of diarrhea clusters among viral and bacterial pathogens, and statistically significant differences (p < 0.001) in event numbers of diarrhea clusters among bacterial pathogens. There were also statistically significant differences (p < 0.001) in the event numbers of diarrhea clusters among public places. Norovirus infections were the first most numerous (77.1%, 1810/2347) diarrhea clusters among viral and bacterial infections. Among bacterial infections, Staphylococcus aureus infections accounted for the greatest number of diarrhea clusters (35.5%, 104/293). Schools were the places with the greatest number of diarrhea clusters (49.1%, 1406/2865) among various institutions. Norovirus single infection (odds ratio, OR = 4.423), Staphylococcus aureus single infection (OR = 2.238), and school (OR = 1.983) were identified as risk factors. This is the first report of confirmed events of diarrhea clusters taken from surveillance data compiled by Taiwan's CDC (2011-2019). This study highlights the importance of long-term and geographically extended studies, particularly for highly fluctuating pathogens, to understand the implications of the transmission of diarrhea clusters in Taiwan's populations. Importantly, big data have been identified that can inform future surveillance and research efforts in Taiwan.