Entomology and Vectorborne Diseases, USAMRU-K Jason Richardson Entomology & Vectorborne Diseases U.S. Army Medical Research Unit-Kenya Rift Valley fever outbreak response Dec 2006 – Feb 2007

Entomology and Vectorborne Diseases, USAMRU-K Highlights Ken Linthicum is omnipotent. Last RVF outbreak in Kenya was in 1997/ Dec Vector surveillance initiated in NE Kenya. 20 Dec Fatalities due to an unexplained fever confirmed as RVF. 14 Dec through today – Vector surveillance 4 ecologically distinct areas of Kenya. > 420 trap nights, > 40 collection sites, > 105,000 mosquitoes, sand flies, and biting midges, > 2,500 pools (760 already tested for RVFV) 30 RVFV positive pools, Virus isolated in cell culture, Virus sequenced Outstanding team effort!

Entomology and Vectorborne Diseases, USAMRU-K

RVFV Background Rift Valley Fever (RVF) is a viral zoonosis. Primarily affects livestock. It is spread by the bite of infected mosquitoes. The disease is caused by the RVF virus, a member of the genus Phlebovirus (family Bunyaviridae). The disease was first reported among livestock in Kenya around 1915, but the virus was not isolated until RVF outbreaks occur across sub-Saharan Africa, Egypt in , several million people were infected and thousands died during a violent epidemic. Saudi Arabia and Yemen – 2000.

Entomology and Vectorborne Diseases, USAMRU-K RVF epidemic foci (Clements et al.,, 2006)

Entomology and Vectorborne Diseases, USAMRU-K Impact Approximately 1% of human sufferers die of the disease. Approximately 1% of human sufferers die of the disease. Amongst livestock the fatality level is significantly higher. Amongst livestock the fatality level is significantly higher. In pregnant livestock infected with RVF abortion rates approach 100%. In pregnant livestock infected with RVF abortion rates approach 100%. An epizootic of RVF is usually first indicated by a wave of unexplained abortions. An epizootic of RVF is usually first indicated by a wave of unexplained abortions.

Entomology and Vectorborne Diseases, USAMRU-K Transmission Cycle Epizootics are dependant on flooding and population densities of flood water Aedes species

Entomology and Vectorborne Diseases, USAMRU-K Transmission Cycle No known vertebrate reservoir. Various competent vectors including Aedes, Culex, Mansonia, Ochlerotatus spp. Sand flies, culicoides, ticks? Efficient mechanical transmission. Transovariol transmission in Ae. mcintoshi, Ae. vexans Blood and milk-borne. Aerosolized virus  lab infections. Man is NOT a dead end host.

Entomology and Vectorborne Diseases, USAMRU-K Dambo

Linthicum, K.J., A. Anyamba, C.J. Tucker, P.W. Kelley, M.F. Meyers, C. J. Peters, 1999: Science, 285, pp

Entomology and Vectorborne Diseases, USAMRU-K

A collaborative project between DoD-GEIS and NASA Goddard Space Flight Center. The ability to map such areas of potential RVF activity 2 to 5 months before outbreaks occur.

Entomology and Vectorborne Diseases, USAMRU-K Rainfall & “Greeness” This Normalized Difference Vegetation Index (NDVI) anomaly map depicts the percent deviation or change from mean vegetation greenness

Entomology and Vectorborne Diseases, USAMRU-K El Nino and Sea Surface Temperatures

Entomology and Vectorborne Diseases, USAMRU-K

Outbreak Response Nov 06 – received an from Dr. Anyamba (GEIS/NASA) warning of a possible RVF outbreak. Nov 06 – received an from Dr. Anyamba (GEIS/NASA) warning of a possible RVF outbreak. 14 Dec 06 – USAMRU-K initiated vector collections in NE Kenya. 14 Dec 06 – USAMRU-K initiated vector collections in NE Kenya. Aedes mcintoshi populations were overwhelming. Aedes mcintoshi populations were overwhelming. Human hemorrhagic fever cases evident. Human hemorrhagic fever cases evident.

Entomology and Vectorborne Diseases, USAMRU-K

Outbreak Response 20 Dec 06 – First confirmed human case. 20 Dec 06 – First confirmed human case. Surveillance  outbreak response planning. Surveillance  outbreak response planning. Risk management Risk management Interagency coord. Interagency coord. CDC CDC USAMRIID USAMRIID NAMRU-3 NAMRU-3 DOS DOS KMOH KMOH

Entomology and Vectorborne Diseases, USAMRU-K KEMRI VHF Reference Lab (GEIS)USAMRIID CDC, Ft Collins NAMRU-3USAMRU-K, Vector-borne Disease Program

Entomology and Vectorborne Diseases, USAMRU-K

Surveillance in NE Kenya

Entomology and Vectorborne Diseases, USAMRU-K Nomadic pastoralists

Entomology and Vectorborne Diseases, USAMRU-K Typical “village”

Entomology and Vectorborne Diseases, USAMRU-K Manyatta – Typical home

Entomology and Vectorborne Diseases, USAMRU-K Herder hooch

Entomology and Vectorborne Diseases, USAMRU-K

Herders live on raw blood & milk

Entomology and Vectorborne Diseases, USAMRU-K Dry ice is not candy

Entomology and Vectorborne Diseases, USAMRU-K

Tick collections

Entomology and Vectorborne Diseases, USAMRU-K Serosurvey

Driving to the coast

Entomology and Vectorborne Diseases, USAMRU-K Driving to the coast

Entomology and Vectorborne Diseases, USAMRU-K Life at the beach

Entomology and Vectorborne Diseases, USAMRU-K Kilifi RVF Case Locations

Entomology and Vectorborne Diseases, USAMRU-K

Lab Results Tested 765 pools by real-time and conventional RT- PCR. Tested 765 pools by real-time and conventional RT- PCR. Detected 30 positive pools (2 species not previously implicated as vectors). Detected 30 positive pools (2 species not previously implicated as vectors). Aedes mcintoshi (11 pools), Aedes mcintoshi (11 pools), Ae. ochraceus (11 pools), Ae. ochraceus (11 pools), Ae. pembaensis (1 pool), Ae. pembaensis (1 pool), An. squamosus (1 pool), An. squamosus (1 pool), Culex bitaeniorhynchus (3 pools), Culex bitaeniorhynchus (3 pools), Cx. poicilipes (3 pools). Cx. poicilipes (3 pools). 12 of 21 sites tested had at least one positive pool. 12 of 21 sites tested had at least one positive pool.

Entomology and Vectorborne Diseases, USAMRU-K Lab Results Minimal field infection rate (MIR) Minimal field infection rate (MIR) MIR = (# pools pos/# of samples) * 1000 MIR = (# pools pos/# of samples) * positive pools (25 per pool) 30 positive pools (25 per pool) specimens tested (to date) specimens tested (to date) MIR = 1.57 MIR = 1.57

Entomology and Vectorborne Diseases, USAMRU-K Lab Results Identified ~40,000 arthropods to date. Identified ~40,000 arthropods to date. > 40 species > 40 species > 10,000 > 10,000 Ae. mcintoshi Ae. mcintoshi

Entomology and Vectorborne Diseases, USAMRU-K Real-Time & Conventional RT-PCR KLF-014 (#4) 588F-946RC probe KLF-085 (#9) 588F-946RC probe KLF-091 (#15) 588F-946RC probe KLF-112 (#33) 588F-946RC probe neg cntl 588F-946RC probe Collected in Kilifi on 13 January 2007 Species: Ae. pembaensis (lane 5); Cx. bitaeniorhynchus (lane 10) Sample: KLF014/04; KLF 085/09 Product 551 bp, Ibrahim et al. 1997

Entomology and Vectorborne Diseases, USAMRU-K Deployable PCR Lab

Entomology and Vectorborne Diseases, USAMRU-K Deployable PCR Lab

Entomology and Vectorborne Diseases, USAMRU-K Deployable PCR Lab

Entomology and Vectorborne Diseases, USAMRU-K Deployable PCR Lab

Entomology and Vectorborne Diseases, USAMRU-K BSL-3 Lab

Entomology and Vectorborne Diseases, USAMRU-K After virus inactivation

Entomology and Vectorborne Diseases, USAMRU-K Containment and Safety RVFV  BSL 3 RVFV  BSL 3 Field (open air processing) Field (open air processing) PPE PPE Prevent aerosolization Prevent aerosolization Inactivate virus Inactivate virus

Entomology and Vectorborne Diseases, USAMRU-K Virus Isolation Vero cells Negative controlCPE from positive mosquito

Entomology and Vectorborne Diseases, USAMRU-K Blast Report for RVFV Isolated in Kenya 2007

Entomology and Vectorborne Diseases, USAMRU-K RVFV Sequence Alignment RVFV Sequence Alignment KEN-1998 and KEN-2007: M Segment Sequencing was conducted at KEMRI, Nairobi, Kenya - Nucleotide Substitutions

Entomology and Vectorborne Diseases, USAMRU-K