Rift valley fever epidemiology and demographics: Difference between revisions

Jump to navigation Jump to search
WikiBot (talk | contribs)
m Changes made per Mahshid's request
 
(3 intermediate revisions by 2 users not shown)
Line 1: Line 1:
__NOTOC__
__NOTOC__
{{Rift valley fever}}
{{Rift valley fever}}
{{CMG}}
{{CMG}}{{AE}} {{AAH}}
==Overview==
The [[Virus|virus]] is able to stay active outside the human body even when it is not being actively transmitted amongst animals. Heavy rain causes [[Mosquito|mosquitos]] to breed in large numbers, which translates into increased transmission to livestock. As more animals get infected, the risk of the virus being transmitted to humans increases. Humans acquire the [[Infection|infection]] by being exposed to animal fluids and products. Most of the disease surges till now have been seen in some regions of Africa and countries belonging to the Arabian peninsula. Since its discovery around the year 1930, there have been [[Outbreak|outbreaks]] of RVF, starting in the 1950 in the African countries, South Africa and Kenya.
 
== Epidemiology and Demographics ==
== Epidemiology and Demographics ==


[[Image:Rift valley fever distribution.jpg|left|thumb|250px|Distribution of Rift Valley Fever in Africa. Blue, countries with endemic disease and substantial outbreaks of RVF; green, countries known to have some cases, periodic isolation of virus, or serologic evidence of RVF.]]
[[File:Rift valley africa map.jpeg|200px|thumb|left|Countries with confirmed cases of Rift Valley fever from July 2009 to November 2010 (indicated in red)<ref>Data were obtained from ProMed-mail (International Society For Infectious Diseases [http://www.promedmail.org]).</ref>]]
 
RVF is generally found in regions of eastern and southern Africa where sheep and cattle are raised, but the virus also exists in most countries of sub-Saharan Africa and in Madagascar. In September 2000, a RVF outbreak was reported in Saudi Arabia and subsequently Yemen. These cases represent the first Rift Valley fever cases identified outside Africa.


RVF virus primarily affects livestock and can cause disease in a large number of domestic animals (this situation is referred to as an "epizootic"). The presence of an RVF epizootic can lead to an epidemic among humans who are exposed to diseased animals. The most notable epizootic of RVF, which occurred in Kenya in 1950-1951, resulted in the death of an estimated 100,000 sheep. In 1977, the virus was detected in Egypt (probably exported there in infected domestic animals from Sudan) and caused a large outbreak of RVF among animals and humans. The first epidemic of RVF in West Africa was reported in 1987 and was linked to construction of the Senegal River Project. The project caused flooding in the lower Senegal River area and altered interactions between animals and humans resulting in transmission of the RVF virus to humans.
==[[Rift valley fever epidemiology and demographics|Epidemiology and Demographics]]==
*The virus is able to stay active outside the human body even when it is not being actively transmitted amongst animals as the Mcintoshi specie of the Aedes mosquito is able to pass on the virus to its progeny. <ref>Huang YM. A new african species of aedes (Diptera: Culicidae). Mosquito systematics 1985; 17:108–120</ref>
*Heavy rain causes mosquitos to breed in large numbers, which translates into increased transmission to livestock.
*Many species of mosquitos and even sandflies and ticks are able to transmit the virus. Other animals like elephants, giraffes and buffaloes are also know to receive the virus through these [[Arthropod|arthropods]].
*As more animals get infected, the risk of the virus being transmitted to humans increases.
*Humans acquire the infection by being exposed to animal fluids and products. There is no evidence suggesting transmission of the virus via mosquito bites. <ref>Nicholas DE, Jacobsen KH, Waters NM. Risk factors associated with human Rift Valley fever infection: systematic review and meta-analysis. Trop Med Int Health 2014; 19:1420–1429</ref>
*Human to human transmission has not been reported till date. Medical personnel did not contract the virus during outbreaks even when they wore little to no personal protective equipment. <ref>Al-Hamdan NA, Panackal AA, Al Bassam TH, Alrabea A, Al Hazmi M et al. The risk of nosocomial transmission of Rift Valley fever. PLoS Negl Trop Dis 2015; 9:e0004314</ref>
*Sexual transmission in humans has not been recorded yet while [[Vertical transmission|vertical transmission]] has been reported in humans and livestock both.
*Most of the disease surges till now have been seen in some regions of Africa and countries belonging to the Arabian peninsula.
*Since its discovery around the year 1930, there have been [[Outbreak|outbreaks]] of RVF, starting in the 1950 in the African countries, South Africa and Kenya.
*In 1974, another episode of increased cases of RVF occurred in South Africa, where around 110 confirmed cases and seven fatalities were reported. <ref>McIntosh BM, Russell D, dos Santos I, Gear JH. Rift Valley fever in humans in South Africa. S Afr Med J 1980; 58:803–806</ref>
*Outbreak of the greatest proportion was later recorded during a two year span starting from 1977 in Egypt, where approximately 200,000 cases were detected which resulted in 598 deaths.<ref>Laughlin LW, Meegan JM, Strausbaugh LJ, Morens DM, Watten RH. Epidemic Rift Valley fever in Egypt: observations of the spectrum of human illness. Trans R Soc Trop Med Hyg 1979; 73:630–633</ref>
*In the year 1997, after a period of heavy rain in East Africa, another outbreak was observed with around 89,000 cases of RVF. <ref>An outbreak of Rift Valley Fever, eastern Africa, 1997-1998. EMHJ 1998; 4:379–381</ref> This led to the first incidence of RVF cases outside the African continent, in Saudi Arabia in the year 2000, with 880 cases and 123 fatalities. <ref>Madani TA, Al-Mazrou YY, Al-Jeffri MH, Mishkhas AA, Al-Rabeah AM et al. Rift Valley fever epidemic in Saudi Arabia: epidemiological, clinical, and laboratory characteristics. Clin Infect Dis 2003; 37:1084–1092</ref>
*There have been numerous incidence of RVF cases in East Africa, since the year 2016.


==References==
==References==

Latest revision as of 15:41, 17 July 2021

Rift valley fever Microchapters

Home

Patient Information

Overview

Historical Perspective

Pathophysiology

Causes

Differentiating Rift valley fever from other Diseases

Epidemiology and Demographics

Risk Factors

Natural History, Complications and Prognosis

Diagnosis

History and Symptoms

Physical Examination

Laboratory Findings

Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Rift valley fever epidemiology and demographics On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Rift valley fever epidemiology and demographics

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Rift valley fever epidemiology and demographics

CDC on Rift valley fever epidemiology and demographics

Rift valley fever epidemiology and demographics in the news

Blogs on Rift valley fever epidemiology and demographics

Directions to Hospitals Treating Rift valley fever

Risk calculators and risk factors for Rift valley fever epidemiology and demographics

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [2]Associate Editor(s)-in-Chief: Aakash Hans, MD[3]

Overview

The virus is able to stay active outside the human body even when it is not being actively transmitted amongst animals. Heavy rain causes mosquitos to breed in large numbers, which translates into increased transmission to livestock. As more animals get infected, the risk of the virus being transmitted to humans increases. Humans acquire the infection by being exposed to animal fluids and products. Most of the disease surges till now have been seen in some regions of Africa and countries belonging to the Arabian peninsula. Since its discovery around the year 1930, there have been outbreaks of RVF, starting in the 1950 in the African countries, South Africa and Kenya.

Epidemiology and Demographics

Countries with confirmed cases of Rift Valley fever from July 2009 to November 2010 (indicated in red)[1]

Epidemiology and Demographics

  • The virus is able to stay active outside the human body even when it is not being actively transmitted amongst animals as the Mcintoshi specie of the Aedes mosquito is able to pass on the virus to its progeny. [2]
  • Heavy rain causes mosquitos to breed in large numbers, which translates into increased transmission to livestock.
  • Many species of mosquitos and even sandflies and ticks are able to transmit the virus. Other animals like elephants, giraffes and buffaloes are also know to receive the virus through these arthropods.
  • As more animals get infected, the risk of the virus being transmitted to humans increases.
  • Humans acquire the infection by being exposed to animal fluids and products. There is no evidence suggesting transmission of the virus via mosquito bites. [3]
  • Human to human transmission has not been reported till date. Medical personnel did not contract the virus during outbreaks even when they wore little to no personal protective equipment. [4]
  • Sexual transmission in humans has not been recorded yet while vertical transmission has been reported in humans and livestock both.
  • Most of the disease surges till now have been seen in some regions of Africa and countries belonging to the Arabian peninsula.
  • Since its discovery around the year 1930, there have been outbreaks of RVF, starting in the 1950 in the African countries, South Africa and Kenya.
  • In 1974, another episode of increased cases of RVF occurred in South Africa, where around 110 confirmed cases and seven fatalities were reported. [5]
  • Outbreak of the greatest proportion was later recorded during a two year span starting from 1977 in Egypt, where approximately 200,000 cases were detected which resulted in 598 deaths.[6]
  • In the year 1997, after a period of heavy rain in East Africa, another outbreak was observed with around 89,000 cases of RVF. [7] This led to the first incidence of RVF cases outside the African continent, in Saudi Arabia in the year 2000, with 880 cases and 123 fatalities. [8]
  • There have been numerous incidence of RVF cases in East Africa, since the year 2016.

References

  1. Data were obtained from ProMed-mail (International Society For Infectious Diseases [1]).
  2. Huang YM. A new african species of aedes (Diptera: Culicidae). Mosquito systematics 1985; 17:108–120
  3. Nicholas DE, Jacobsen KH, Waters NM. Risk factors associated with human Rift Valley fever infection: systematic review and meta-analysis. Trop Med Int Health 2014; 19:1420–1429
  4. Al-Hamdan NA, Panackal AA, Al Bassam TH, Alrabea A, Al Hazmi M et al. The risk of nosocomial transmission of Rift Valley fever. PLoS Negl Trop Dis 2015; 9:e0004314
  5. McIntosh BM, Russell D, dos Santos I, Gear JH. Rift Valley fever in humans in South Africa. S Afr Med J 1980; 58:803–806
  6. Laughlin LW, Meegan JM, Strausbaugh LJ, Morens DM, Watten RH. Epidemic Rift Valley fever in Egypt: observations of the spectrum of human illness. Trans R Soc Trop Med Hyg 1979; 73:630–633
  7. An outbreak of Rift Valley Fever, eastern Africa, 1997-1998. EMHJ 1998; 4:379–381
  8. Madani TA, Al-Mazrou YY, Al-Jeffri MH, Mishkhas AA, Al-Rabeah AM et al. Rift Valley fever epidemic in Saudi Arabia: epidemiological, clinical, and laboratory characteristics. Clin Infect Dis 2003; 37:1084–1092

Template:WH Template:WS