In Tanzania, according to the Ministry of Health, the epidemic raging in Ruangwa district, in the Lindi region, is caused by leptospirosis or “Homa ya Mgundaas it is called in Swahili. Test results of 20 patient samples from Ruangwa were all positive for the disease. While contact tracing is ongoing, no other person among the contacts has shown symptoms of the disease so far.
Reminder about leptospirosis
Leptospirosis is a disease caused by bacteria worldwide. Leptospirosis is caused by bacteria Leptospira’s interrogator. This is quite easily maintained in the external environment (fresh water, muddy soil), promoting pollution. The seasonal nature of the disease is very pronounced, with summer-autumn outbreaks related to temperature and rainfall.
Bacteria of the genus Leptospira are capable of infecting a large number of wild mammals (rodents and insectivores: rats, tengues, shrews, etc.) and domestic animals (cattle, sheep, etc.) , goats, pigs, dogs), they act as reservoirs and excrete in their urine. Bacteria can survive for several months in a warm, humid environment. There are more than 250 serovars of Leptospira species, with some serovars endemic to a certain geographical area.
Certain occupations (farmers, livestock, drainage workers, garbage collectors, etc.) and people who practice water sports (swimming, canoeing, kayaking, fishing, etc.) hunting, canyon digging, etc.) are especially at risk. In humans, the bacteria enter mainly through injured skin or mucous membranes.
The disease is usually mild, but complications can occur, including kidney failure which can lead to death in 5 to 20% of cases. The incubation period is 4-14 days.
- In the moderate form, the disease begins with a high fever accompanied by chills, headache, and diffuse myalgia and arthralgia. In 20% of cases, it is complicated by hemorrhagic syndrome.
- Severe forms (icterohaemorrhagic or Weil’s disease) combine acute renal failure, neurasthenia (convulsions, coma) and profuse bleeding (pulmonary, gastrointestinal).
The initial nonspecific clinical signs (headache, fever, myalgia) can lead to delays in diagnosis and treatment due to confusion with differential diagnoses such as influenza, chikungunya, or dengue.
Precautions and personal protection against leptospirosis
- Avoid swimming in fresh water, especially when you have an injury, and when the water is cloudy or muddy;
- Avoid contact with water, nose, mouth and eyes;
- Avoid walking barefoot or wearing open sandals on muddy ground, standing puddles, ravines (especially in surgical departments);
- Protect the wound from contact with water with a waterproof dressing;
- Wear protective equipment during high-risk occupational activities (livestock, wastewater workers, garbage collectors, farmers, land work, etc.) including boots, gloves, wading gear water, protective clothing, even splash-proof goggles in case of exposure hazard; practice white water sports such as canyoning, kayaking, including protective suits, boots and gloves.
- Control rodents, which are reservoirs of disease.
After taking the risk:
- Wash with drinking water and disinfect the wound;
- Consult a doctor immediately in the event of the appearance of symptoms, informing him of the dangerous activity carried out in the previous two weeks.
These measures will be strengthened during the rainy season.
There is a vaccine against leptospirosis. Its effectiveness is limited to certain strains of leptospira, it is rarely done in practice, mainly involving specialists.