Health authorities in the Peruvian capital city of Lima are on alert due to rises in mosquito populations. The most dreaded type - the Aedes aegypti, potential carrier of various diseases including the Zika virus, dengue fever, chikungunya, and yellow fever - has been detected in 36 of the capital region’s 43 districts. Cases of the Zika virus are beginning to be detected and the numbers are likely to rise.
The government is calling on residents to destroy potential mosquito breeding grounds - i.e. pockets of stagnant water, such as rain water that has collected in cans, bottles, tires, flower pots, clogged gutters, etc. The epidemiological risk is particularly high in poorer areas (e.g. on the outskirts of the city) without running water, as residents are forced to store water in large tanks, a major potential host of mosquito larvae. Fumigation efforts are also underway.
It should also be noted that a major dengue fever epidemic is ongoing in the northwest of the country (Piura region), which was hit by significant flooding earlier in the year.
While the Zika virus in itself is usually relatively benign (and asymptomatic in approximately 80 percent of cases), links between the Zika virus and severe birth defects as well as the potentially fatal neurological disorder Guillain-Barre syndrome (GBS), have been established. When symptoms do occur they generally appear two to seven days following contraction of the disease, and include fever, headache (behind the eyes), conjunctivitis, rash, vomiting, and muscle and joint pain.
Symptoms of classic dengue fever include fever, headache, muscle and joint pain, fatigue, nausea, and rash. Dengue Hemorrhagic Fever (DHF) is a potentially deadly complication that is characterized by high fever, enlargement of the liver, and hemorrhaging.
Symptoms of chikungunya are similar to those of dengue fever and include: high fever, joint and muscle pain, rash, headache, nausea, and fatigue. The virus is rarely fatal but lingering joint pain can last for several months, even years, after the initial recovery.
Individuals present in Lima - and Peru more generally - are advised to take measures to protect themselves from mosquito bites, e.g. by wearing covering clothing, using insect repellent, and sleeping in a screened-in or air conditioned room. Travelers who develop any of the above symptoms after returning home should make sure their doctors are aware of their travel history to avoid misdiagnosis.