Salmonellosis: symptoms, rehydration and when an antibiotic is not needed - in Tashkent

How do salmonella get to the plate?

Salmonella lives in the intestines of birds and animals and enters food in two ways. The first is from inside the product: laying hens infected with certain strains lay eggs in which the bacteria are already under the shell, and not just on its surface. Therefore, a perfectly clean-looking egg does not provide any guarantee, and “homemade” here does not mean “safe.” The second way is cross-contamination in the kitchen: the same board and the same knife after raw chicken, the same bowl in which the meat was defrosted, the hands used to break the egg and then cut the salad.

Next comes temperature. Salmonella multiply in approximately the range from 7 to 45 degrees, and they are most comfortable at human body temperature. In the summer, in a kitchen where it is 30 degrees or higher, the number of bacteria in a dish doubles in 20–30 minutes: a few hours on the table turns a safe amount into a dose that is enough to cause illness. That is why outbreaks are almost always associated not with the product itself, but with how long the finished dish was kept warm and under what conditions it was transported from the market.

• Soft-boiled eggs and fried eggs with liquid yolk, homemade mayonnaise, cake cream, eggnog
• Chicken and turkey that are not fully cooked at the back of the piece, especially near the bone
• Shish kebab, lula and cutlets removed from heat with pink center
• Salads with meat, egg and mayonnaise, standing for several hours without refrigeration
• Raw milk and products made from it that have not undergone heat treatment
• Ready-made dishes, heated not to a boil, but simply to a warm state
• Greens and vegetables washed in the same sink immediately after cutting raw poultry

The key thing to remember is that the contaminated product does not smell, does not change color and does not give off any foreign taste. Salmonella does not spoil food; spoilage is caused by completely different microorganisms. Therefore, the usual test of “smell and taste” is useless here, and the decision about whether to eat a dish or throw it away is made based on the time and temperature of storage, and not on how it feels.

The second underestimated point is freezing. It stops the proliferation of bacteria, but does not kill them: after thawing, the process resumes from the same place. Worse, if the product was defrosted at room temperature, the surface has time to heat up and become a nutrient medium long before the middle thaws. For the same reason, the habit of carrying purchased chicken or minced meat in the trunk of a car for several hours in a row is dangerous: even without obvious heat, during this time the product goes all the way from cold to room temperature.

How the disease progresses: from the first hours to recovery

From the entry of bacteria to the first symptoms, it usually takes from 6 to 72 hours, more often 12–24 hours. This interval explains a common source-tracing error: people blame the last thing they ate, even though the culprit was usually the food the day before. Further events develop in a fairly recognizable way, and it is useful to understand this sequence - it helps to assess at what stage the disease is and what to expect next.

1. Первые часы: тошнота, слабость, познабливание, тяжесть и урчание в животе, затем рвота — иногда многократная.
2. Первые сутки: температура поднимается до 38–39 с ознобом, присоединяется схваткообразная боль вокруг пупка и в правой половине живота.
3. Next: обильный водянистый стул, часто зеленоватый и с резким запахом, до десяти и более раз в сутки; рвота обычно стихает раньше, чем понос.
4. Вторые-третьи сутки: температура снижается, стул постепенно оформляется; главной угрозой на этом этапе становится накопленная потеря жидкости, а не сама инфекция.
5. Третьи-седьмые сутки: самочувствие восстанавливается, но слабость, плохая переносимость жирного и молочного и неустойчивый стул могут держаться ещё одну-две недели.

In children under five years of age and in people over 65, the picture is the same, but there are fewer reserves: dehydration develops in hours, not in days, and it is these two groups that most often end up in the hospital. A separate feature of the disease is bacterial excretion. After recovery, salmonella continues to be excreted in the feces for an average of 4–6 weeks in adults and longer in young children, while the person feels completely healthy. This is not a relapse or a sign that the disease was “undertreated”, but a natural completion of the infection. It is of practical importance primarily for those who work with products, in child care institutions and in medicine.

Dehydration is something to really be afraid of.

The severity of the disease is determined not by the bacterium itself, but by the loss of water and salts. With stool and vomiting, not only liquid is lost, but also sodium, potassium, chlorides - substances on which the functioning of the heart, muscles and kidneys depends. Therefore, drinking plain water only solves the problem halfway: water without salts quickly disappears, and the concentration of electrolytes continues to fall. It is worth knowing the signs of increasing dehydration by heart - they appear before a person feels really unwell.

• Thirst, dry mouth, decreased amount of urine, deep yellow urine
• Dry lips and tongue, skin folds straighten slowly
• Weakness, dizziness when standing up, rapid heartbeat
• In a child: crying without tears, sunken fontanel at the breast, dry diaper for six hours or longer
• No urine for 8–12 hours, sunken eyes, pale and cool skin
• Drowsiness from which it is difficult to recover, confusion - a condition for urgent help

1. Аптечный регидратационный порошок разводят строго на указанный объём воды: концентрация здесь важнее вкуса, «покрепче» делает раствор хуже, а не лучше.
2. Если порошка нет, рекомендованный ВОЗ домашний вариант — на литр кипячёной остуженной воды шесть чайных ложек сахара без горки и половина чайной ложки соли.
3. Пить не залпом, а мелкими глотками или по чайной ложке каждые 3–5 минут: большой объём сразу провоцирует новую рвоту.
4. Ориентир объёма — примерно стакан раствора после каждого жидкого стула у взрослого и несколько ложек после каждого эпизода у ребёнка.
5. Контроль простой: появилась светлая моча обычной частоты — жидкости достаточно.
6. Если удержать жидкость не удаётся дольше 6–8 часов или признаки обезвоживания нарастают, нужна капельница, и откладывать её опасно.

Separately, let’s talk about what the rehydration solution should not be replaced with. Sweet soda, packaged juices and energy drinks contain too much sugar: its excess in the intestinal lumen attracts water and increases diarrhea. Strong tea and coffee have a diuretic effect. Milk is poorly tolerated in the acute period: temporary lactose intolerance after an intestinal infection is a common phenomenon that goes away in one to two weeks. But fasting is not necessary and harmful: the intestinal mucosa recovers faster when it receives nutrition. A reasonable approach is to eat small portions of what is tolerated, starting with rice water, porridge with water, crackers, banana and baked apple.

Why antibiotics often hinder rather than help

This is the main misunderstanding around salmonellosis. The logic “there is a bacteria - you need an antibiotic” seems impeccable, but with the usual intestinal form it does not work. In people without risk factors, the antibiotic does not reduce either the duration of diarrhea or the duration of fever, but it significantly lengthens the period during which Salmonella continues to be excreted in the feces. The reason is that the drug suppresses the intestinal microflora - the same one that naturally displaces the pathogen. The decision to prescribe is made by the doctor, and the list of situations when an antibiotic is really needed is quite narrow.

• Children in the first months of life
• Elderly patients, especially those with prosthetic blood vessels, heart valves and joints
• Reduced immunity: cancer treatment, HIV infection, taking hormones and immune-suppressing drugs
• Severe course with high fever for more than three days and suspected release of bacteria into the blood
• Condition after removal of the spleen, sickle cell anemia, decompensated diabetes mellitus
• Confirmed damage outside the intestines - joints, bones, lining of the heart

There is a second reason not to start treatment on your own. Salmonella resistance to common drugs is growing, and the selection of an antibiotic in cases where it is needed is increasingly based on culture with sensitivity testing. A course started “by eye” the day before a visit to the doctor deprives the laboratory of the opportunity to grow the pathogen: the culture becomes negative, but the disease does not go away.

Means that stop diarrhea deserve special mention. At high temperatures, and even more so when there is blood in the stool, they are dangerous: by slowing down the intestines, they trap both bacteria and their toxins inside. Sorbents moderately reduce the frequency of stool, but do not replenish water and salts, so taking them instead of a solution for drinking is pointless. Enzyme preparations and means “to restore flora” do not affect the course of the acute period and do not solve the issue of dehydration.

What tests make sense?

Typically, the diagnosis is made clinically, and a person with a mild form does not need extensive testing. But there are situations when laboratory confirmation is essential: severe disease, group illness in a family or team, working with food products and in child care facilities, hospitalization, the need to resolve the issue of an antibiotic.

1. Посев кала — main метод: позволяет вырастить сальмонеллы и определить чувствительность к препаратам, результат обычно через 3–5 дней.
2. ПЦР кала — быстрее и находит сразу группу возбудителей, но чувствительность к антибиотикам не показывает.
3. Посев крови — при температуре выше 39 дольше трёх суток, ознобах и тяжёлом состоянии; отвечает на вопрос, вышла ли инфекция за пределы кишечника.
4. Общий анализ крови — выраженность воспаления, а гематокрит служит косвенным показателем сгущения крови при обезвоживании.
5. Электролиты, креатинин и мочевина — при выраженном обезвоживании и у пожилых, чтобы вовремя заметить страдание почек.
6. Контрольные посевы после выздоровления — для работников пищевых, детских и медицинских учреждений; их сроки определяются регламентом, а не самочувствием.

Two studies solve almost nothing, although they are often prescribed. A blood test for antibodies to salmonella in acute intestinal infection is delayed: antibodies appear at the end of the first or second week, when a person is already recovering, and persist for months after the illness, so a positive result does not answer the question “am I sick now.” The second is a study on the composition of microflora, which is often called an analysis for dysbacteriosis: it is not a method for diagnosing intestinal infections and does not replace culture. If the task is to find the pathogen, the stool is specifically examined for pathogenic flora.

Prevention in hot summer conditions

Salmonellosis is a seasonal disease, and its peak occurs in the hot months simply because at this time the main rule of food safety is violated: cold things must remain cold, and hot things must remain hot. Between 5 and 60 degrees there is a zone in which bacteria multiply freely, and all home prevention comes down to ensuring that food spends as little time as possible in this zone.

• The finished dish should not stand at room temperature for more than two hours, and in heat above 30 degrees - longer than an hour
• The temperature in the refrigerator is no higher than 5 degrees; You should check it with a thermometer, not by touch
• The poultry and eggs are brought to full readiness: the white and yolk are dense, the juice when the chicken is punctured is clear
• Separate board and knife for raw meat, wash them with hot water and detergent immediately after use
• Eggs are washed immediately before cooking and are not stored washed: the washed away protective film facilitates the penetration of bacteria through the shell
• Defrost meat in the refrigerator or in cold water, not on the counter
• Dishes with raw eggs - homemade mayonnaise, cream, eggnog - exclude for children, pregnant women and the elderly
• Reheating - to a boil and warming up the entire mass, and not to a warm state

Separately, about the situation when someone in the family is already sick. Salmonellosis is also transmitted from person to person, especially where there are small children: a shared towel, door handle and unwashed hands are enough. During the illness and for several weeks after it, it is wise to provide the sick person with a separate towel and dishes, wash your hands with soap after each visit to the toilet and after caring for the child, and wash clothes at high temperatures. A person who has recently suffered from an intestinal infection should not prepare food for the whole family: this is how one case turns into a family outbreak that lasts for a month.