# Presentation: 672182

## West Nile Guidelines

**West Nile Guidelines**

## 1999 WN virus activity in NYC area

**1999 WN virus activity in NYC area**

- Mosquitoes

- Birds

- Humans

**Notes:**
Green dots on this slide represent the locations of WNV infected mosquito pools, the majority of which were culex species.  Although no human cases were documented in NJ, positive mosquitoes pools were identified.  Northern Queens had the highest concentration of infected mosquitoes.

## Distribution of West Nile Virus as of October 1999

**Distribution of West Nile Virus as of October 1999**

**States with WN virus**

## Slide 4

## West Nile Fever: Background and Epidemiology

-  **First isolated in West Nile district, Uganda, 1937**
**Commonly found in humans and birds and other vertebrates in Africa, Eastern Europe, West Asia, and the Middle East, but has not previously been documented in the Western Hemisphere**
**  ****Basic transmission cycle involves mosquitoes feeding on birds infected with the West Nile virus**
** ****Infected mosquitoes then transmit West Nile virus to humans and animals when taking a blood meal**

## West Nile Fever: Classical Clinical Description

-   **Asymptomatic or mild dengue-like illness**
**  ****Fever, lymphadenopathy, headache, abdominal pain, vomiting, rash, conjunctivitis**
**  ****Incubation period usually 5 (3) to 15 days**
**  ****CNS involvement and death in minority of cases**

## West Nile Virus Transmission Cycle

**West Nile Virus Transmission Cycle**

**West Nile**
**virus**

**West Nile**
**virus**

- Mosquito vector

- Incidental infections

- Bird
- reservoir hosts

- Incidental  infections

## West Nile Outbreaks

**Israel - 1951-1954, 1957**
**France - 1962**
**South Africa - 1974**
**Romania – 1996**
**Italy 1998**
**Russia - 1999**
**United States –1999-2000**
**Israel – 2000**
**France - 2000**

## WN Virus Testing of Specimens Submitted to DVBID 

**1 (8/99)**

**1 (7/99)**

**1 (2/96)**

**1 (7/96)**

**1 (9/96)**

**1 (8/96)**

_**New York**_

**1 (8/96)**

**2 (7/98; 9/98)**

**1 (2/99)**

_**Puerto Rico**_

**1 (8/97)**

**1 (10/98)**

**1 (9/96)**

**1 (6/98)**

**2 (9/98)**

**12 (7,8,9/98)**

**1 (11/98)**

**1 (1/99)**

**1 (1/99****)**

**1 (1/99)**

**WN Virus Testing of Specimens Submitted to DVBID **
**for SLE Virus Testing**

**# Specimens (Onset Date Mo/Yr)**

- N=32

## West Nile Virus in the US Some Possible Pathways of Introduction

**Infected human host**
**Human-transported vertebrate host**
**Legal**
**Illegal**
**Human-transported vector(s)**
**Storm-transported vertebrate host (bird)**
**Intentional introduction (terrorist event****)**

## Slide 11

## Slide 12

## Slide 13

## Serum, CSF

**Mosquito pools, Tissues**

**Serological**
**Assays**

**Virus Detection**
**Assays**

**IgM ELISA**
**IgG ELISA**
**PRNT**
**CF**
**HI**
**IFA**
**Dipsticks****

**Virus isolation (cells, mice)**
**IFA**
**TaqMan RT-PCR****
**Ag-capture ELISA**
**RT-PCR / sequencing**
**Dipsticks****
**NASBA****

**Diagnostic Assays for Arboviruses**

## Slide 15

## Long Term WN virus IgM activity in human serum

**NYCDOH-CDC collaborative study**

**N=28**

## Flaviviral IgM Cross-reactivities in Human Sera

## s

- e

**Antiviral MAb to well**

**Unknown virus sample**

**Antiviral MAb conjugate**

**Substrate addition**

**Antigen Capture Assay**

## Origin of the West Nile virus responsible for an outbreak of encephalitis in the northeastern U.S. 

**Origin of the West Nile virus responsible for an outbreak of encephalitis in the northeastern U.S. **

## Full-length Genomic NT Homology Among WN Viruses

| Virus | NY99Fl | NY99Eq | Is98St | Ita98Eq | Ro97Mo | Eg101 |
| --- | --- | --- | --- | --- | --- | --- |
| NY99Fl |  | 99.9 | 99.7 | 96.5 | 96.7 | 95.5 |
| NY99Eq |  |  | 99.7 | 96.5 | 96.7 | 95.5 |
| Is98St |  |  |  | 96.3 | 96.5 | 95.4 |
| Ita98Eq |  |  |  |  | 98.6 | 95.5 |
| Ro97Mo |  |  |  |  |  | 95.6 |
| Eg101 |  |  |  |  |  |  |

## Attenuating Mutations of JE virus E-glycoprotein vs. WN Variants

**126**

**159**

**107**

**315**

**138**

**176**

**177**

**264**

**279**

**439**

**227**

**244**

_**Stem **_

**JE changes**

**Old vs. New World**
** ****WN changes**

## West Nile 2000

## Jurisdictions Funded for Enhanced WN Surveillance

**New York City**

**Philadelphia**

**Houston**

**Los Angeles**

**Washington, D.C.**

**Jurisdictions Funded for Enhanced WN Surveillance**

**First Round $$**

**Second Round $$**

## Purpose for Distribution of $9.9 Million in 

**Will**** ****WN virus overwinter in the United States**

**Has WN virus spread from the Northeastern United**** ****States**

**Rebuild vector-borne disease infrastructure**
**at the**** ****State level**

**Purpose for Distribution of $9.9 Million in **

**Emergency Funding for WN Virus  **

## Partnerships for West Nile Virus in the United States

**Centers for Disease Control and Prevention**
**U.S. Department of Agriculture**
**U.S. Geological Survey**
**Department of Defense**
**Environmental Protection Agency**
**State and Local Health Departments**
**State and Local Veterinarians**
**State and Local Wildlife Biologists**

## Slide 26

## West Nile Virus in the United States

**Monitor geographic and temporal spread**
**Develop more effective strategies for surveillance, prevention and control**
**Define regional distribution and incidence of other arbovirus diseases**
**Provide current national and regional information**

**National Surveillance Plan**

## Estimated Sensitivity of West Nile Virus Surveillance Methods

## First Surveillance Events in Relation to Hypothetical West Nile Viral Activity; Richmond Co. and US, 2000

- Aug

- Sep

- Oct

- Jul

- Jun

- Apr

- Mar

- Viral activity

**Crow,**
**Suffolk**

***Ae. japonicus*****,**
** ****Westchester;**
***Cx. pipiens*****,**
** ****Richmond**

**Horse,**
**Richmond**

**Human,**
**Richmond**

**Sentinel **
**Chicken,**
**Westchester**

**Crow,**
**Richmond**

## Summary results of avian, veterinary, and mosquito West Nile virus surveillance, 2000

**4,315 birds representing 76 species in 12 states and Washington, DC**
**Epizootic expanded to new mammal species including bats, chipmunks, rabbits, and squirrels.**
**483 mosquito pools representing five states and 12 species [*****Ochlerotatus (=Aedes) cantator, trivittatus, triseriatus,  japonicus; Aedes vexans, albopictus; Anopheles punctipennis; Culiseta melanura; Culex pipiens, restuans, salinarius; Psorophora ferox*****]**

## Illness onset for 78 persons hospitalized with WNV infections, U.S., 1999-2000

**2000**

**1999**

## Serosurvey Results 

| Location | Participants | Positives | Seroprevalence (%) |
| --- | --- | --- | --- |
| NYC 1999
Queens | 677 | 19 | 2.6 |
| NYC 2000
Staten Is. | 871 | 4 | 0.46 |
| NYS 2000
Suffolk Co. | 834 | 1 | 0.12 |
| CT 2000
Fairfield Co. | 731 | 0 | 0.0 |

## Other Highlights

**Developed and implemented MAC-EIA for equines and chickens ****(USDA, CDC)**
**Developed and implemented a recombinant WN virus antigen (prM-E) ****(CDC)**
**Evaluated WN virus infection in chickens, sparrows, crows and other avian species ****(CDC,USGS)**
**Identified bird-to-bird transmission cycles ****(USGS, CDC)**
**Sponsored 6 laboratory training courses for WN virus diagnosis ****(2000-2001, CDC)**
**Completed full-length genome sequencing on nine WN virus strains ****(CDC-7; UCI-1; Pasteur Institute -1)**

## Other Highlights

**Identified overwintering WN virus in NYC mosquitoes ****(NYCDOH, NYS, CDC)**
**Conducted field investigations to determine meaning of infected crows and assess seasonal expansion of WN virus ****(Local health depts., NYCDOH, NYS, NJ, CDC, USGS, DOD)**
**Developed contingency plans for large scale WN virus control ****(State, CDC)**
**Developing mosquito identification, collection and processing training course ****(CDC, others)**

## Conclusions - Questions

**WN virus has expanded its distribution in the U.S. and will likely be endemic for the near future.  *****What will happen in 2001?***
**The types of mosquito vectors affected have increased which will change the virus transmission dynamics.  *****How will this change prevention and control strategies?***
**WN virus is an important epizootic agent.  *****Do we need prevention and control strategies for animals?  ***
**Vector control efforts likely reduced human cases incidence in 2000.  *****Can this be proven?***

## Conclusions - Questions

**Continued progress on improving vector-borne disease infrastructure is still needed.  *****Are current efforts succeeding?****** ***
**Enhanced surveillance is effective in determining the spread of WN virus. *****Can surveillance better predict human risk?***
**Much research is needed to fully understand the impact of WN virus on the Western Hemisphere.  *****What are the most important questions to answer?***