Mar 20, 2026
3 min read
Bacteria from the mouth can affect the liver. Vancomycin-resistant Enterococci remain a challenge. Oropouche virus can harm the fetus.
Each week on the Infectious Disease Blog, we provide you with a brief overview of the latest developments in the epidemiology, diagnosis and treatment of COVID-19, influenza and other infectious diseases.
Infectious diseases news blog, updated 19.3.2026
- COVID-19, influenza, RSV - German trends
- Influenza: composition of flu vaccines for the 2026/2027 season
- 2 Cases of Tuberculosis in Dresden Schools - Department of Public Health Examinations contacts
- Colds: Why some infections are more serious than others
- Vancomycin-resistant enterococci: a challenge for hospitals
- Microbiome: When bacteria in the mouth affect the liver
- Oropouche virus: danger to unborn children?
COVID-19, influenza, RSV: trends in Germany
The Federal Ministry of Health collects trends in acute respiratory diseases (ARE) on the "Pollution Radar" website. Last 7-day incidence (lab-confirmed cases per 100,000 inhabitants):
|current week |previous week ||
|COVID-19 |0.7 |0.5 |
|Influenza |5,66 |13,57 |
|Respiratory syncytial virus (RSV) |1.01 |1.19 |
During the 11th calendar week, ARE activity in the population dropped again. Examining the virological data, it is clear which pathogens are currently playing a role. In the samples examined, seasonal coronaviruses and respiratory syncytial virus (RSV) predominated, followed by rhinoviruses and human metapneumoviruses. Although influenza viruses continue to be identified, they currently play only a minor role.
Overall, the development shows that the normal wave of cold and flu continues to subside and the infection process is now under control.
Flu: Production of flu vaccines for the 2026/2027 season
The World Health Organization (WHO) has published influenza vaccine recommendations for the upcoming winter season, based on global surveillance data on the spread of viruses.
For egg-based vaccines, the vaccine must contain the following types:
- A/Missouri/11/2025 (H1N1)pdm09-like virus
- A/Darwin/1454/2025 (H3N2) virus simile.
- Virus like B/Tokyo/EIS13-175/2025 (B/Victoria lineage).
For protein or DNA vaccines based on cell culture, the World Health Organization recommends:
- A/Missouri/November 2025 (H1N1)pdm09-like virus
- A/Darwin/1415/2025 (H3N2) – bug tracking
- B/Pennsylvania/14/2025 (B/Lineage Victoria) Virus
On this basis, vaccine manufacturers can now start production so that there is enough vaccine for next winter.
Cases of tuberculosis in 2 schools in Dresden.health service tests contact persons
Doctors have confirmed cases of infectious tuberculosis in two schools in Dresden.According to the city's health department, two people have tested positive for the infectious bacterial disease.Both patients are in isolation and receiving medical treatment.Meanwhile, the health directorate has started testing people who come into contact with the school environment as a precautionary measure.
Tuberculosis is considered a difficult disease to transmit.However, close contact with sick people may pose a risk.For this reason, students and staff at the affected schools are currently being tested.If the first test is negative, a second test is usually required after 8-12 weeks, especially in children and adolescents.Only then can infection be ruled out with certainty.
Colds: Because some illnesses are worse than others
Rhinoviruses are the most common cause of the common cold.Although infections are mild for most people, some at-risk groups, such as smokers or asthmatics, may have significant breathing problems.It is partially understood why.The results of the new study now provide information about which mechanisms in the nasal epithelium determine how strongly the body responds to infection.This was reported by Cell Press Blue Scientists.
Using three-dimensional cell models of human nasal mucosa and a new single-cell array, they were able to analyze in detail the immune response to rhinoviruses.It was shown that the total interferon response provides effective protection.Virus replication is limited to less than 2% of infected cells.
However, when this early antiviral defense is disrupted, the response of the immune system changes significantly.Viruses can multiply faster and at the same time trigger a pronounced inflammatory reaction.Among others, the signaling pathways of the inflammatory factor NF-κB and the immune receptor NLRP1 are activated.As a result, more and more of the messenger substance interleukin-1β is released, which further increases inflammation and triggers excessive mucus production in the airways.
Research shows that different patterns of innate immune activation determine how severe rhinovirus infection is.The researchers also identified NLRP1 as a potential future therapy to limit the excessive inflammatory response to colds.
Vancomycin-resistant enterococci: a challenge for hospitals
Vancomycin-resistant enterococci (VRE) are among the most important multidrug-resistant pathogens encountered in hospitals.They cause infections mainly in seriously ill patients, for example in intensive care units or internal medicine departments.Particularly problematic is its resistance to vancomycin, an antibiotic that is often used as a support.
However, the current data published in the Epidemiological Bulletin show an ambiguous evolution.On the one hand, the proportion of Enterococcus faecium resistant to vancomycin has decreased significantly in recent years: while in 2019 about 26% of invasive isolates were resistant, in 2024 the proportion was only about 11%.This means that Germany is now below the EU average.
However, molecular analyzes show the dynamic development of resistance mechanisms.The resistance genes vanA and vanB are particularly widespread, allowing the pathogen to change the cell wall, so that vancomycin is not effective.In recent years, the vanA type has been increasingly discovered, while many types of VRE develop additional resistance to other antibiotics, which makes treatment more complicated.
Therefore, infection prevention is still important for hospitals.This includes surveillance programs, hygiene practices and antibiotic treatment.Modern molecular techniques such as genetic sequencing can quickly and accurately detect outbreaks and trace supply chains.
Microbiome.When oral bacteria affect the liver
A new study suggests that changes in the oral flora may be linked to autoimmune liver disease, report researchers in Clinics and Research in Hepatology and Gastroenterology.
In a systematic review, they analyzed several observational studies in which the oral microbiota of patients with autoimmune liver disease was compared to that of healthy people. In total, data from almost 600 people were included, including patients with autoimmune hepatitis and primary biliary cholangitis.
All the studies reviewed demonstrated an altered composition of bacteria in the patients' mouths.Researchers particularly often found elevated levels of bacteria from the genus Veillonella, while some studies reported lower levels of other bacteria such as Streptococcus or Fusobacterium.
At the same time, some work has found that patients have higher concentrations of inflammatory markers in saliva than healthy controls.The scientists found a link between a high concentration of Veillonella and greater indicators of inflammation, while Streptococcus was associated with lower levels of inflammation.
Some studies also examined gut flora or tissue samples.There was evidence of reduced microbial diversity, changes in bacterial composition, and increased permeability of the intestinal barrier.
These findings support the concept of the mouth-gut-liver axis, in which changes in the oral flora can contribute to inflammation of the liver through the immune system.The nature of the data can still be controlled.However, the results show that the disturbance of the oral microbiome may be a factor that has not been considered before in the development of autoimmune liver diseases.
Oropouche virus: a threat to unborn babies?
Oropuche virus is increasingly common in Latin America and can also pose a risk to pregnant women.In a review article, researchers evaluated studies and case reports to examine the potential effects of infection during pregnancy.
The virus is transmitted primarily by small mosquitoes and often causes self-limiting disease, but its symptoms can easily be confused with other mosquito-borne viral infections.
There is growing evidence that the virus can be transmitted from mother to fetus.In individual cases, miscarriages and birth defects such as microcephaly or other brain changes have been observed.Analysis of viral genetic material from placental and fetal tissue supports this idea.
As there is no specific treatment or vaccine, prevention, especially avoiding mosquito bites, is of utmost importance.Researchers also call for better surveillance systems and further research to further clarify the risks to pregnant women and their children.
