INTRODUCTION
Emerging infectious diseases, particularly zoonotic diseases, present a substantial threat to human populations. Humans have co-existed and combated with infectious diseases since ancient times. In an endeavor to combat infectious diseases, there has been a growing recognition among the human population of specific diseases. Infectious diseases pose a significant threat to human health [1]. Seasonal variations commonly impact the transmission of respiratory infectious diseases, especially influenza. There is a notable prevalence of respiratory infectious diseases during the autumn and winter seasons, leading to a substantial increase in the risk of such illnesses [1]. Low temperature and humidity create favorable conditions for the survival and replication of viruses. The primary sources of respiratory infectious diseases are typically patients and carriers of pathogens that predominantly lead to infections through aerosol respiratory droplets. Patients diagnosed with respiratory infectious diseases commonly exhibit a range of respiratory symptoms, including fever, cough, and expectoration. It is feasible to strategize and execute disease prevention and control interventions proactively, including the administration of vaccines.
To maximize visualization of the region and pattern of infectious disease development we utilized Shusi Tech’s Global Epidemic Information Monitoring System to perform a systematic and comprehensive analysis of global infectious diseases between September and December 2023 (Fig 1).
INFLUENZA
Acute respiratory infections, such as influenza, are prevalent worldwide, particularly during cold weather conditions. Individuals are also susceptible to infectious diseases during seasonal outbreaks. Influenza remained prevalent in 2023, which was not unexpected [2].
Compared to other infectious diseases, the incidence of influenza has significantly increased in the last 4 months (September-December 2023), primarily affecting the United States, Australia, and Canada. Fatalities were documented to occur in Australia during December 2023 (Fig 2A). Among the nations affected by influenza, the United States reported the highest number of influenza cases. With approximately 50,000 new cases reported between September and December 2023, there has been a significant surge in the incidence from October-December (Fig 2B). The Netherlands reported the first case of human infection with the influenza A (H1N1) virus variant on 2 September 2023. Influenza transmission rates exhibit seasonality, with a tendency for widespread outbreaks during colder weather conditions.
DENGUE
The worldwide prevalence of dengue fever has notably increased in the last 20 years, presenting a substantial challenge to public health. The global incidence of dengue fever has been steadily increasing since the start of the year, with greater than 5 million reported cases and a significant number of dengue-related fatalities.
During the final 4 months of 2023, there was a significant surge in newly confirmed cases of dengue fever, predominantly occurring in Bangladesh and Mexico. Compared to the preceding 8 months of 2023, there was an upward trend in the number of dengue cases for the top 11 countries over the last 4 months (Fig 3). Dengue is endemic year round in Colombia, Nicaragua, Peru, and Brazil. The actual number of cases has likely been underestimated due to a significant proportion of asymptomatic cases and the lack of mandatory reporting of dengue in numerous countries.
Statistics of the top 11 new confirmed dengue cases in the above countries or regions (September-December 2023). Bangladesh, Mexico, Nicaragua, Vietnam, Columbia, Malaysia, Peru, Taiwan, China, Sri Lanka, Bolivia and Argentina are the top 11 regions reported new dengue cases over the last 4 months.
MONKEYPOX (MPOX)
Mpox is a zoonotic disease transmitted by the Mpox virus [3]. New cases of Mpox mainly occur in the Americas. There was a significant increase in the number of Mpox cases from September-November 2023 (Fig 4A), with Thailand and Japan closely following this trend. Portugal also experienced an epidemic over the past 4 months (Fig 4B). There were 592 cumulative suspected cases from the Americas, with 5 reported deaths during this period (Fig 4B). Notably, although there were few confirmed cases in Taiwan, China during this period, the first Mpox-associated death was reported in Taiwan, China (Fig 4B).
Statistics of new Mpox cases from September-December 2023. A. Number of confirmed cases of Mpox infections per month from September-December 2023. B. Statistics of the above countries or regions about cumulative suspected Mpox cases and Mpox-associated mortality. Germany, Korea, United States, Portugal, Japan, Thailand, Italy, Indonesia, Taiwan, China, Hongkong, China and Macao, China are the top 11 regions reported cumulative suspected Mpox cases over the last 4 months.
CHOLERA
Cholera, a major public health concern, is caused by Vibrio cholerae, resulting in a high number of infections and fatalities annually [1]. The cumulative suspected cholera cases were concentrated in Afghanistan from September-December 2023. Fig 5 shows the top 6 countries in the list of new cholera cases in the past 4 months.
Statistics of the cumulative suspected cholera cases in the above countries or regions (September to December, 2023). Afghanistan, Zimbabwe, Haiti, Democratic Republic of Timor-Leste, Mozambique and Somalia are the top 6 countries reported cumulative suspected cholera cases over the last 4 months.
MEASLES
Measles, a highly contagious viral infection, is one of the leading causes of death, especially among children under <5 years of age in developing countries. According to World Health Organization (WHO) data from September-December 2023, several countries around the world experienced measles outbreaks. Topping the list was Ethiopia, which reported >7000 confirmed cases of measles, followed by Yemen with >6000 cases. Additionally, Afghanistan, Pakistan, Russia, and Nigeria all had thousands of cases. It is important to note that the People’s Republic of the Congo, which had up to 60,000 suspected cases during the past 4 months, only reported 700 measles cases due to a lack of laboratory confirmation (Table 1).
Worldwide measles cases reported between September and December 2023.
| Record period | Location | Cumulative suspected cases (confirmed cases) reported during the record period | Cumulative deaths reported during the record period | Data source |
|---|---|---|---|---|
| 01/01/2023-26/08/2023 | Afghanistan | 20049 (2257) | 60 | WHO Regional Office for the Eastern Mediterranean |
| 01/01/2023-02/09/2023 | 20403 (2376) | 62 | ||
| 01/01/2023-09/09/2023 | 20735 (2381) | 62 | ||
| 01/01/2023-16/09/2023 | 21041 (2385) | 62 | ||
| 01/01/2023-23/09/2023 | 21347 (2385) | 62 | ||
| 01/01/2023-14/10/2023 | 22145 (2454) | 62 | ||
| 01/01/2023-21/10/2023 | 22408 (2425) | 62 | ||
| 01/01/2023-28/10/2023 | 22687 (2455) | 62 | ||
| 01/01/2023-18/11/2023 | 23571 | |||
| 01/01/2023-04/11/2023 | 22996 (2462) | 63 | ||
| 01/01/2023-18/11/2023 | 23571 (2468) | 64 | ||
| 01/01/2023-25/11/2023 | 23850 (2468) | 64 | ||
| 01/01/2023-09/12/2023 | 24591 (2627) | 64 | ||
| 01/01/2023-16/12/2023 | 24995 (2631) | 64 | ||
| 01/01/2023-23/10/2023 | Ethiopia | 18899 | 149 | WHO Regional Office for Africa |
| 01/01/2023-18/10/2023 | 18899 | 149 | ||
| 12/08/2021-26/11/2023 | 25104 | 195 | United Nations Office for the Coordination of Humanitarian Affairs | |
| 01/01/2023-12/12/2023 | Austria | 172 | EU CDC | |
| 01/01/2023-05/09/2023 | 154 | |||
| 01/01/2023-09/10/2023 | 157 | |||
| 01/01/2023-12/09/2023 | Pakistan | 24604 (11557) | WHO | |
| 01/01/2023-06/11/2023 | 30366 (14758) | |||
| 01/01/2023-26/08/2023 | Paraguay | 1116 | WHO Regional Office for the Americas | |
| 01/01/2023-23/09/2023 | 1145 | |||
| 01/01/2023-04/11/2023 | 1225 | |||
| 01/01/2023-26/08/2023 | Brazil | 1462 | ||
| 01/01/2023-23/09/2023 | 1566 | |||
| 01/01/2023-04/11/2023 | 1858 | |||
| 01/01/2023-07/09/2023 | Germany | 98 | EU CDC | |
| 01/01/2023-09/10/2023 | 107 | |||
| 01/01/2023-13/12/2023 | 126 | |||
| 01/01/2023-12/09/2023 | Russia | 6414 (2858) | WHO | |
| 01/01/2023-09/10/2023 | 7055 (3099) | |||
| 01/01/2023-05/12/2023 | 11220 (6076) | |||
| 01/01/2023-06/11/2023 | 7464 (3378) | |||
| 01/01/2023-09/10/2023 | The Philippines | 2785 (1237) | WHO | |
| 01/01/2023-06/11/2023 | 3197 (1514) | |||
| 01/01/2023-05/12/2023 | 3352 (1622) | |||
| 01/01/2023-03/09/2023 | Democratic Republic of The Congo | 234255 (3076) | 4415 | WHO Regional Office for the Eastern Mediterranean |
| 01/01/2023-29/10/2023 | 282323 (3719) | 5330 | United Nations Office for the Coordination of Humanitarian Affairs | |
| 01/01/2023-05/11/2023 | 298132 (3775) | 5727 | ||
| 01/01/2023-26/08/2023 | Colombia | 1219 | WHO Regional Office for the Americas | |
| 01/01/2023-23/09/2023 | 1322 | |||
| 01/01/2023-04/11/2023 | 1489 | |||
| 01/01/2023-21/08/2023 | Kyrgyzstan | 2743 (1774) | 2 | Outbreak News Today |
| 01/01/2023-17/10/2023 | 2842 | ProMED-mail | ||
| 01/01/2023-05/12/2023 | 4662 (3811) | WHO | ||
| 01/01/2023-13/08/2023 | Cameroon | 5863 (5838) | 30 | WHO Regional Office for Africa |
| 01/01/2023-05/11/2023 | 6034 | 31 | ||
| 01/01/2023-05/12/2023 | 6635 (6123) | |||
| 01/01/2023-06/11/2023 | Cote d’Ivoire | 4477 (916) | WHO | |
| 01/01/2023-05/12/2023 | 4740 (992) | |||
| 01/01/2023-12/09/2023 | 4043 (821) | |||
| 01/01/2023-22/10/2023 | Kenya | 1325 | WHO Regional Office for Africa | |
| 13/12/2021-21/09/2023 | Liberia | 12885 (12213) | 95 | WHO Regional Office for Africa |
| 13/12/2021-30/10/2023 | 12967 (12298) | 95 | ||
| 01/01/2023-05/12/2023 | 4524 (4357) | WHO | ||
| 01/01/2023-05/10/2023 | Romania | 920 | EU CDC | |
| 01/01/2023-06/11/2023 | 978 | WHO | ||
| 01/01/2023-05/12/2023 | 2000 | ProMED-mail | ||
| 01/01/2023-06/11/2023 | Malaysia | 6771 (1278) | WHO | |
| 01/01/2023-05/12/2023 | 8016 (1543) | |||
| 01/01/2023-12/09/2023 | 4056 (458) | |||
| 01/01/2023-09/10/2023 | 5164 (574) | |||
| 01/01/2023-04/11/2023 | Mexico | 1961 | WHO Regional Office for Africa | |
| 01/01/2023-26/08/2023 | 1476 | |||
| 01/01/2023-23/09/2023 | 1679 | |||
| 08/10/2022-28/10/2023 | South Africa | 1267 | ProMED-mail | |
| 01/01/2023-06/11/2023 | 5397 (887) | |||
| 08/10/2022-25/11/2023 | 1317 | |||
| 08/10/2022-16/12/2023 | 1338 | |||
| 08/10/2022-02/09/2023 | 6816 (1160) | |||
| 08/10/2022-16/09/2023 | 7008 (1183) | |||
| 08/10/2022-24/09/2023 | 7054 (1199) | |||
| 08/10/2022-30/09/2023 | 7123 (1214) | |||
| 01/01/2023-15/10/2023 | South Sudan | 6328 (521) | 149 | WHO Regional Office for Africa |
| 01/01/2023-15/10/2023 | 6328 | |||
| 01/01/2023-12/09/2023 | Nigeria | 15607 (10574) | WHO | |
| 01/01/2023-06/11/2023 | 17392 (11421) | |||
| 01/01/2023-05/12/2023 | 18130 (11323) | |||
| 01/01/2023-09/10/2023 | Yemen | 39644 (37359) | WHO | |
| 01/01/2023-16/10/2023 | 40130 | 362 | ||
| 01/01/2023-06/11/2023 | 45975 (43675) |
DIPHTHERIA
Diphtheria is a preventable bacterial infection for which a vaccination exists. Diphtheria is caused by the bacterium, Corynebacterium diphtheriae. In 2023 there were 23,182 diphtheria cases globally, with Nigeria accounting for 19,411 cases or 83.7% of the global diphtheria cases (Table 2). Other South African countries, such as the Republic of Guinea and Niger, have also experienced outbreaks of diphtheria.
Worldwide diphtheria cases reported in 2023.
| Record period | Location | Cumulative suspected cases (confirmed cases) reported during the record period | Cumulative deaths reported during the record period | Data source |
|---|---|---|---|---|
| 01/12/2023-12/12/2023 | Germany | 90 | EU CDC | |
| 01/01/2023-07/11/2023 | Netherlands | 14 | EU CDC | |
| 01/01/2023-26/11/2023 | The Republic of Guinea | 1216 (1079) | 71 | WHO Regional Office for Africa |
| 01/01/2023-12/11/2023 | Mauritania | 20 | 5 | WHO Regional Office for Africa |
| 01/01/2023-12/11/2023 | South Africa | 79 (9) | 1 | WHO Regional Office for Africa |
| 01/01/2023-26/11/2023 | Niger | 2346 (2194) | 128 | WHO Regional Office for Africa |
| 01/01/2023-03/12/2023 | Nigeria | 19411 (11831) | 575 | WHO Regional Office for Africa |
| 01/05/2023-10/09/2023 | Vietnam | 6 | 1 | Ministry of Health of Vietnam |
SPORADIC INFECTIOUS DISEASES
The incidence of other infectious diseases has also been sporadically reported. According to the data from the last 4 months, there has been a general decreasing trend in the rate of detecting insect-borne infectious diseases. Insect-borne infectious diseases, such as West Nile fever, Chikungunya fever, and leishmaniasis, have emerged in Asian and African countries on a small scale.
In contrast, there has been a malaria recurrence in many African and South American countries and remains a highly endemic disease in developing countries. In 2023 >3.24 million people were infected with malaria in Ethiopia and >1.33 million people were infected with malaria in Pakistan. In the past 4 months, Ethiopia and Pakistan have each experienced >100,000 new infections every month. Malaria outbreaks have also occurred in The Congo, Zimbabwe, and Sudan. However, there is less surveillance of malaria deaths, and there is an urgent need for increased monitoring of malaria cases along with appropriate interventions for malaria control and elimination programs to effectively address the public health burden (S1 Table).
CONCLUSION
Infectious diseases have consistently been underscored as a significant factor influencing advances in human society. Since the turn of the last century, there have been >1000 infectious disease-associated deaths, totaling 1.68 billion, which is >10-fold the number of deaths caused by wars. The predominant challenge we are currently encountering pertains to the persistent risk posed by newly emerging infectious diseases. The emergence of emerging infectious diseases is characterized by a rise in the prevalence of zoonotic diseases. The increased diversity in transmission modes simultaneously poses numerous challenges to the prevention and control of infectious diseases.
The majority of infectious diseases occur during the autumn and winter months. As winter approaches, the air becomes drier and colder, creating favorable conditions for various infectious diseases, particularly the influenza virus. In addition to enhancing our own protection, it is advisable to maintain a balanced routine of work and rest, follow a scientifically balanced diet, and engage in regular exercise to boost our immunity. Early detection, prompt isolation, timely diagnosis, and immediate treatment play a crucial role in effectively halting the spread and transmission of infectious diseases.