Doctor Le Thi Gam, Medical Manager at VNVC Vaccination System, noted that the period after the Tet holiday and leading into festival season sees a high demand for travel, gatherings, and large crowds. This creates favorable conditions for infectious agents to spread widely within the community. People can be exposed to various sources of infection. Below are four common sources of disease transmission in the community to be aware of:

Human-to-human transmission

Infectious diseases such as flu, respiratory syncytial virus (RSV), pneumococcus, meningococcus, whooping cough, and measles spread directly through respiratory droplets when coughing, sneezing, talking, or through close contact. This is especially prevalent in crowded environments. Some diseases have high transmission rates; for instance, whooping cough can infect 12-17 people, and RSV can infect 4-5 people. Individuals with flu can transmit the virus from one day before symptoms appear and for 5-7 days thereafter.

Pathogens also persist on surfaces, easily entering the body when hands touch these surfaces and then are brought to the eyes, nose, or mouth. Many infected individuals can still transmit the disease even with mild or unclear symptoms.

Vaccines are currently available to prevent many of these diseases: flu vaccine for children from six months old and adults, requiring annual boosters; pneumococcal vaccine with five types, administered from six weeks old; RSV vaccine for people over 60 years old and pregnant women from 24-36 weeks, and monoclonal antibodies for infants up to 24 months old.

People receiving flu vaccinations early in the year at VNVC Vaccination System. Photo: Binh An

Animal-to-human transmission

Some infectious diseases can spread from animals to humans through bites, scratches, or contact with secretions. Rabies, in particular, is extremely dangerous, with a near-absolute fatality rate once symptoms develop. The rabies virus is found in the saliva of warm-blooded animals like dogs, cats, monkeys, and bats. When it enters the body through a wound, the virus attacks the nervous system, causing symptoms of agitation, hydrophobia, convulsions, and eventually death.

Recently, a six-year-old child in Quang Tri died from rabies, and outbreaks in dogs have been recorded in many localities. Vaccination and antiserum administration are currently the only preventive measures. The post-exposure vaccination regimen includes five intramuscular doses or eight intradermal doses. Rabies vaccine can also be given as pre-exposure prophylaxis, with three basic doses, which reduces the number of post-exposure doses and eliminates the need for antiserum if exposure occurs.

Mosquito-borne transmission

After Tet, many areas still have standing water in jars, tires, and bottles, creating breeding grounds for mosquitoes. Mosquitoes are dangerous vectors for diseases such as dengue fever, Japanese encephalitis, malaria, and yellow fever. When an infected mosquito bites a person, the virus or parasite directly enters the bloodstream, often starting with flu-like symptoms that can lead to complacency.

Dengue fever can progress severely, causing shock, hemorrhage, and multi-organ failure. Japanese encephalitis has a fatality rate of up to 30% and leaves many severe sequelae.

In addition to measures like eliminating mosquito larvae, sleeping under nets, and wearing long-sleeved clothing, people are advised to get vaccinated. Japanese encephalitis vaccine is available in both the expanded immunization program and private services, administered to children from nine months old and adults. Dengue fever vaccine is given to children from four years old and adults, consisting of two doses three months apart, which helps prevent the disease, inhibit reinfection, and reduce hospitalization rates by over 90%.

A case of dengue fever admitted to the National Hospital for Tropical Diseases in a state of shock and hemorrhage. Photo: BVCC

Food-borne transmission

Unsafe food and water can be sources of many gastrointestinal diseases such as cholera, typhoid, and hepatitis A. Pathogens often exist in raw food, undercooked seafood, contaminated drinking water, or food prepared and stored under poor hygienic conditions.

These diseases can cause symptoms such as abdominal pain, diarrhea, vomiting, fever, dehydration, and fatigue. In some severe cases, patients may experience severe dehydration, electrolyte imbalance, or liver damage, impacting health if not treated promptly.

Doctor Gam recommends that people eat cooked food, drink boiled water, choose safe food, and ensure hygiene during preparation. Individuals can also get vaccinated to build active antibodies. Hepatitis A vaccine is available as a single dose or combined with hepatitis B prevention; the single dose is indicated for people from 12 months to under 16 years old or from 24 months to under 18 years old, depending on the vaccine type, with two doses at least six months apart. The combined dose is for children from 12 months old and adults.

The cholera vaccine is administered orally to people from two years old, with a regimen of two doses at least two weeks apart. The typhoid vaccine is administered as a single dose to people from two years old, with a booster dose every three years if there is a risk of infection.

Binh An