Insect-borne diseases pose immense health & economic threats
Call us for an expert pest survey on 1800-212-212-5
Zika virus identified in a captive rhesus monkey in the Zika forest of Uganda in routine surveillance for yellow fever.
The virus is recovered from the mosquito Aedes (Stegomyia) africanus, caught on a tree platform in the Zika forest.
The first human cases of virus infection are detected in Uganda and the United Republic of Tanzania.
The virus is isolated from a girl in Eastern Nigeria.
Brazil is declared free of Aedes aegypti (the main vector for dengue, yellow fever, chikungunya and Zika) following an extensive eradication programme using DDT to control a yellow fever outbreak.
Two more Zika virus strains are isolated from Aedes africanus mosquitoes in the Zika forest area.
Zika detected in mosquitoes and test rhesus monkeys in a narrow band of countries that stretch across equatorial Africa. The virus is isolated from more than 20 mosquito species, mainly in the genus Aedes. Studies indicate widespread human exposure to the virus but the disease is regarded as benign.
The first proof that the Zika virus causes human disease. A researcher in Uganda falls ill while working with Zika strains isolated from mosquitoes.
The known geographical distribution of Zika expands to equatorial Asia, including India, Indonesia, Malaysia and Pakistan, where the virus is detected in mosquitoes and in the human population.
The first large outbreak of Zika in humans on the Pacific island of Yap, in the Federated States of Micronesia. Prior to this event only 14 cases of human Zika virus disease had been documented worldwide. An estimated 73% of Yap residents over three years of age were infected with Zika virus. No deaths, hospitalizations, or neurological complications are reported.
A US scientist conducting field work in Senegal falls ill with Zika after returning home to Colorado. He infected his wife in what is thought to be the first documented case of sexual transmission of an insect-borne disease.
Analysis of Zika virus strains collected in Cambodia, Malaysia, Nigeria, Senegal, Thailand and Uganda, show two geographically distinct lineages of the virus in Africa and Asia. The outbreak on Yap Island was confirmed to have originated in South East Asia.
First evidence Zika may be sexually transmitted. On Tahiti in French Polynesia a patient recovering from Zika seeks reports having bloody semen, which is found to contain Zika virus.
Zika outbreak in four other groups of Pacific islands: French Polynesia, Easter Island, the Cook Islands, and New Caledonia. The outbreak in French Polynesia causes thousands of suspected infections. The first reports of a possible association between Zika virus infection and congenital malformations and severe neurological and autoimmune complications, in particular, Guillain-Barré syndrome.
A dengue outbreak in Brazil reached 1.5 million cases, showing the extent of the Aedes aegypti re-emergence.
First evidence of transmission of Zika from mother to foetus. In French Polynesia, two mothers and their newborns are found to have Zika virus infection. The babies’ infections appear to have been acquired during pregnancy or during delivery.
Brazil notifies WHO of outbreak of unknown illness characterized by skin rash with or without fever in north eastern states — 13% tested positive for dengue.
The disease in NE Brazil is confirmed to be Zika, making it the first outbreak in the Americas. The Pan American Health Organization (PAHO) and WHO issue an epidemiological alert to Zika virus infection.
Brazil reports neurological disorders associated with patients having infection of Zika, chikungunya or dengue. 49 cases confirmed as Guillain-Barré syndrome.
Zika reported in Republic of Cabo Verde and Columbia.
Brazil reports 54 cases of microcephaly among newborns.
Zika reported in Suriname.
Brazil reports Zika virus in amniotic fluid of two pregnant women whose foetuses have microcephaly (confirmed by ultrasound). Suspected microcephaly cases reach 739 cases across nine states.
Brazil declares a national public health emergency.
The United States reports the first locally acquired Zika infection, in the Commonwealth of Puerto Rico.
Zika reported in Guyana, Ecuador, Barbados, Hawaii (also increase in microcephaly), Bolivia, Haiti, Saint Martin, El Salvador (also increase in Guillain-Barré syndrome), Dominican Republic, US Virgin Islands, Nicaragua, Curacao, Suriname, Jamaica. One case in Finnish national returning from Maldives.
The first diagnoses of intrauterine transmission of the Zika virus in two pregnant women in Brazil whose foetuses were diagnosed with microcephaly. Zika virus is detected in amniotic fluid even though the mothers tested negative.
Ophthalmologists in Brazil report severe eye malformations in three infants born with microcephaly.
The Unites States issues travel guidance for pregnant women which, “out of an abundance of caution”, advises them to consider postponing travel to areas with Zika outbreak or to take precautions against mosquito bites if they must travel. Creates worldwide interest in Zika.
WHO declares a Public Health Emergency of International Concern due to the association of Zika infection with microcephaly and other neurological disorders.
21 July: The Oswaldo Cruz Foundation in Brazil reported it had detected the Zika virus in Culex quinquefasciatus mosquitoes collected in Pernambuco State.
26 July: Inovio Pharmaceuticals and GeneOne Life Science announced the dosing of the first subject in its multi-center phase I trial to evaluate Inovio’s Zika DNA vaccine (GLS-5700).
29 July: US reported the first cases of mosquito-borne virus transmission of Zika, in Florida.
Up to 3 August: A total of 11 countries have reported person-to-person transmission. A total of 68 countries and territories have reported mosquito-borne transmission of Zika.
3 August: The US National Institutes of Health announced it had launched a Phase 1 clinical trial of a DNA vaccine for Zika on 80 volunteers.
WHO declared an end to Public Health Emergency of International Concern (PHEIC) for microcephaly, other neurological disorders and Zika virus. The WHO Emergency Committee recommended that the Zika programme should be escalated into a sustained programme of work.
65 countries had reported an outbreak or possible transmission in 2015 and 2016.
WHO reports that more than 40 vaccine candidates are being developed and 5 are entering phase I clinical trials. Registration of first generation vaccines is expected in 2-3 years.
The Zika virus RNA is found in Aedes albopictus mosquitoes in Brazil. Male mosquitoes were also found with the virus RNA, which means it must have passed from the mother to the egg, as males do not feed on blood (research conducted by University of Florida Institute of Food and Agricultural Sciences).
Brazil declares an end to its public health emergency over the Zika virus, saying infections are down 95% compared to 2016, but WHO still classifies the country as Category 1: Area with new introduction or reintroduction with ongoing transmission.
MK Kindhausera, T Allena, V Franka, RS Santhanaa, C Dye. Zika: the origin and spread of a mosquito-borne virus. Bulletin of the World Health Organization. Published online: 9 February 2016, (link).
Fernando A. Monteiro, Renata Shama, Ademir J. Martins, Andrea Gloria-Soria, Julia E. Brown, Jeffrey R. Powell. Genetic Diversity of Brazilian Aedes aegypti: Patterns following an Eradication Program. Published: September 18, 2014. PLOS Neglected Tropical diseases, (link).