Global & Disaster Medicine

Archive for the ‘Chikungunya’ Category

PAHO: The total number of chikungunya cases in the Americas grew by 207 after leaping by more than 7,000 cases the week before.

Countries with current or previous local transmission of chikungunya virus, listed in below data table


Pakistan’s Ministry of National Health Services, Regulations and Coordination has reported cases of Chikungunya in the country for the first time.


Chikungunya reported in Pakistan

27 February 2017 – Pakistan’s Ministry of National Health Services, Regulations and Coordination has reported cases of Chikungunya in the country for the first time.

A total of 803 cases have been reported since 19 December 2016 in the Sindh province, including 29 cases reported in various towns in Karachi during the week of 10-16 February 2017. Of the 92 samples sent to the National Instituted of Health for testing, 71 have been laboratory-confirmed postive for Chikungunya virus.

WHO is in close coordination with the Ministry of Health and partners in response efforts. Capacity-building has been conducted and instructions issued to district and town health officers, primary health care providers and hospitals on Chikungunya treatment and preventative measures.

The community has been advised through a door-to-door campaign through the Lady Health Workers programme. Affected areas have been fumigated and high-risk areas have been treated with insecticides using indoor residual spraying.


AGS-v: An investigational vaccine that triggers an immune response to mosquito saliva rather than to a specific virus or parasite carried by mosquitoes


The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), has launched a Phase 1 clinical trial to test an investigational vaccine intended to provide broad protection against a range of mosquito-transmitted diseases, such as Zika, malaria, West Nile fever and dengue fever, and to hinder the ability of mosquitoes to transmit such infections. The study, which is being conducted at the NIH Clinical Center in Bethesda, Maryland, will examine the experimental vaccine’s safety and ability to generate an immune response.

Mosquito vaccine trial partipant recieves injection

The investigational vaccine, called AGS-v, was developed by the London-based pharmaceutical company SEEK, which has since formed a joint venture with hVIVO in London. The consulting group Halloran has provided regulatory advice to both companies.

Unlike other vaccines targeting specific mosquito-borne diseases, the AGS-v candidate is designed to trigger an immune response to mosquito saliva rather than to a specific virus or parasite carried by mosquitoes. The test vaccine contains four synthetic proteins from mosquito salivary glands. The proteins are designed to induce antibodies in a vaccinated individual and to cause a modified allergic response that can prevent infection when a person is bitten by a disease-carrying mosquito.

“Mosquitoes cause more human disease and death than any other animal,” said NIAID Director Anthony S. Fauci, M.D. “A single vaccine capable of protecting against the scourge of mosquito-borne diseases is a novel concept that, if proven successful, would be a monumental public health advance.”

Led by Matthew J. Memoli, M.D., director of the Clinical Studies Unit in NIAID’s Laboratory of Infectious Diseases, the clinical trial is expected to enroll up to 60 healthy adults ages 18 to 50 years. Participants will be randomly assigned to receive one of three vaccine regimens. The first group will receive two injections of the AGS-v vaccine, 21 days apart. The second group will receive two injections of AGS-v combined with an adjuvant, 21 days apart. The adjuvant is an oil and water mixture commonly added to vaccines to enhance immune responses. The third group will receive two placebo injections of sterile water 21 days apart. Neither the study investigators nor the participants will know who is assigned to each group.

Participants will be asked to return to the clinic twice between vaccinations and twice after the second vaccination to undergo a physical exam and to provide blood samples. Study investigators will examine the blood samples to measure levels of antibodies triggered by vaccination.

Each participant also will return to the Clinical Center approximately 21 days after completing the vaccination schedule to undergo a controlled exposure to biting mosquitoes. The mosquitoes will not be carrying viruses or parasites, so the participants are not at risk of becoming infected with a mosquito-borne disease. Five to 10 female Aedes aegypti mosquitoes from the insectary in NIAID’s Laboratory of Malaria and Vector Research will be put in a feeding device that will be placed on each participant’s arm for 20 minutes. The mosquitoes will bite the participants’ arms through the netting on the feeding devices.

Afterward, investigators will take blood samples from each participant at various time points to see if participants experience a modified response to the mosquito bites as a result of AGS-v vaccination.

Investigators also will examine the mosquitoes after the feeding to assess any changes to their life cycle. Scientists suspect that the mosquitoes who take a blood meal from ASG-v-vaccinated participants may have altered behavior that could lead to early death or a reduced ability to reproduce. This would indicate that the experimental vaccine could also hinder disease transmission by controlling the mosquito population.

All participants will be asked to return to the clinic for follow-up visits every 60 days for five months following the mosquito feeding. A final clinic visit to assess long-term safety will take place approximately 10 months after the mosquito feeding. Throughout the trial, an independent Data and Safety Monitoring Board will review study data to evaluate participant safety and the overall conduct of the study. A medical monitor from NIAID’s Office of Clinical Research Policy and Regulatory Operations will also perform routine safety assessments.

The study is expected to be completed by summer 2018. For more information about the trial, see using the trial identifier NCT03055000 (link is external).

The Pan American Health Organization (PAHO) in the first 2 weeks of 2017 reported 4,008 new suspected, confirmed, and imported chikungunya cases, mostly in Brazil, bringing the 2016-17 total in the Americas to more than 500,000.


	Countries with current or previous local transmission of chikungunya virus, listed in below data table


Mosquito-disseminated pyriproxyfen (PPF), a potent juvenile-killing insecticide, has potential to block mosquito-borne virus transmission citywide


Abad-Franch F, Zamora-Perea E, Luz SLB (2017) Mosquito-Disseminated Insecticide for Citywide Vector Control and Its Potential to Block Arbovirus Epidemics: Entomological Observations and Modeling Results from Amazonian Brazil. PLoS Med 14(1): e1002213. doi:10.1371/journal.pmed.1002213




Chikungunya: 304,322 suspected, confirmed, and imported cases have been reported in the Americas & the number of deaths this year stayed even at 106.


Patients are packing hospitals across New Delhi because of chikungunya. In the Indian capital alone, cases of chikungunya soared to 3,251 so far this year from just 64 last year.



Chikungunya – Kenya


Disease outbreak news
9 August 2016

On 28 May 2016, the Ministry of Health of Kenya notified WHO of an outbreak of Chikungunya in Mandera East sub-county.

The first reports of an increase in cases with febrile illness and joint pains occurred in May 2016. Samples were collected and shipped to the Kenya Medical Research Institute (KEMRI) Arboviral Laboratory in Nairobi. On 16 May, KEMRI laboratory confirmed 7 of the 10 samples tested positive for Chikungunya virus. All samples tested negative for other arboviruses including: dengue, yellow fever and West Nile viruses.

Moreover, from partial sequencing of the envelope gene it was observed that the CHIK isolates from Mandera are grouped with isolates from the post-2005 Indian Ocean islands, Asia and Europe. Full genome sequencing is underway.

To date, KEMRI has received a total of 177 samples of suspected cases in the laboratory for testing. Of thse, 53 of these came from Somalia and rest from Mandera. 57 were positive by IgM antibody testing and 38 were positive for CHIK virus by RT-PCR. Of the positives, 9 were both IgM and PCR positive.

As of 30 June 2016, 1,792 cases had been line listed. No deaths have been reported so far. However there is a risk of underreporting of cases since many patients are not reporting to health facilities. There have been outbreaks of Chikungunya in neighbouring Bula Hawa region in Somalia border region originating from Mogadishu. It is estimated that about 80% of the population and 50% of the health work force in Mandera town were affected by Chikungunya. Cases with severe debilitating joint pains were being managed as inpatients for a short duration for 1 or 2 days. However, the majority of the cases are not seeking treatment in health facilities.

Public health response

WHO country office supported the Ministry of Health to dispatch seven technical staff to support the County government of Mandera in risk assessment. WHO supported a rapid vector assessment survey, it was observed that most of the breeding habitats for the Aedes vectors for chikungunya in Mandera are within domiciliary containers mainly for water storage. The density of day-biting Aedes vectors were substantially high and County vector control activities were minimal.

A cross border and coordination meeting between Somalia and Kenya took place on 30 May 2016 to coordinate joint response activities to control the outbreak. The meeting recommended a lead agency to coordinate response activities across the border and to improve coordinated surveillance and information sharing. Other partners who were part of the response included MSF and Kenya Red cross. MSF supplied 30,000 treated mosquito nets, which targeted about 30% coverage for the population at risk. The MOH also provided 5000 ITNs for hospital use and chemicals for vector control.

The last outbreak of Chikungunya in Kenya was in 2004 and 2005, where at least 1,300 cases were documented. The affected areas were Lamu and Mombasa in the Coast region. A seroprevalence survey done in October 2004 suggested that 75% of the population in Lamu had been affected.

WHO risk assessment

In the past, the outbreak that began in 2004, on the Kenyan coast reached the Comoros at the end of 2004 before spreading to the Indian Ocean islands in 2005. A mutation in the E1 gene and selection chikungunya virus strains that increase adaptation of the virus to one of the vector Aedes albopictus and therefore significantly increase transmissibility has likely occurred in Reunion Island at the end of 2005 and resulted in an unprecedented outbreak and a further spread to the rest of the world.

If confirmed the preliminary sequencing results the circulation of the mutated chikungunya stain could yield significantly higher attack rate than with the formerly circulating African strain. Ae albopictus is an invasive species that continues to expand geographically in various parts of the world, could therefore represent a further risk of geographical extension the current outbreak in the affected countries and beyond .

The risk for a moderate to high scale outbreak of Chikungunya in the area cannot be ruled out due to the presence of the disease vector, immunologically naive population and potential upcoming rains in the area. Besides potential cross border span of the outbreak, under-reporting of cases and low levels of health seeking behaviours among the affected population is concerning.


PAHO last week reported 1,708 new suspected or confirmed chikungunya cases, bringing the total in the Americas this year to 214,547.


Chikungunya, el virus que encorva


New chikungunya cases: From Jul 8 to Jul 15, PAHO reported only 1,479 new suspected or confirmed cases, bringing the total in the Americas this year to 195,628.

	Poster:  Were you recently in the Caribbean?  Mosquitoes spread Chikungunya and Dengue.  Watch for fever with joint pains or rash in the next 2 weeks.  If you are sick, see a doctor.


Recent Posts