Shoo Fly, Don’t Infect Me!

Mechanical Vectors of Bacterial GI Diseases

Liz Melton

March 9th, 2012

Coincides with Vector Habitat/Behavior:

-latrines (human and animal feces)

-unsanitary overcrowding

-refugee/prisoner of war camps

-areas with inadequate screening techniques

-on dead corpses

-unfiltered garbage composts 

www.un.org/millenniumgoals/pdf/mdg2007.pdf

HUMANITARIAN CRISIS – Mechanical Transmission

What is Mechanical Transmission?

“a form of indirect transmission in which the infectious agent does not

undergo physiologic changes inside the vector” (CDC

definition)

Hinshaw, J. (Photographer). (2000). [Photograph]. Retrieved February 13, 2012, from: http://www.worldwidewounds.com/2000/oct/Janet-Hinshaw/Larval-Therapy-Human-and-Veterinary.html.

Examples:*fly-bornecockroach-borne coprophagic beetle-borne

Common Mechanical Vectors

• House Flies• Filth Flies• Blowfly• Cockroaches

Orangeacid. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/orangeacid/189512184/sizes/z/in/photostream/.

Lerlind. (Photographer). [Photograph] Retrieved February 13, 2012, from: http://www.flickr.com/photos/lerlind/3520284423/sizes/z/in/photostream/.

Keiding J. The housefly—biology and control. Training and information guide (advanced level). Geneva, World Health Organization, 1986 (unpublished document WHO/VBC/ 86.937; available on request from Division of Control of Tropical Diseases, World Health Organization, 1211 Geneva 27, Switzerland).

Characteristics:

• Common Cockroach

-5-73 mm in length

-2 pair of wings

-flattened appearance

-yellow/brown color

-agile

-exhibits endophagic behavior

-active at night, in latrines

*RESPONSIBLE FOR:•Diarrheal diseases•Typhoid fever•Dysentery

Hinshaw, J. (Photographer). (2000). [Photograph]. Retrieved February 13, 2012, from: http://www.worldwidewounds.com/2000/oct/Janet-Hinshaw/Larval-Therapy-Human-and-Veterinary.html.

Egypt Scenario

METHODS:

1) Surveyed residential areas in Khaldyia Village, Egypt 2009 – 2010

• 45 cockroaches collected in control, 178 total collected

• Flies from human feces also observed

2) Parasites isolated/identified from defecation areas in and around houses

“The role of cockroaches and flies in mechanical transmission of medically important parasites”Journal of Entomology and Nematology, Gehad T. El-Sherbini and Eman T. El-Sherbini, 2011

(Photograph). [Photograph]. Retrieved February 13, 2012, from: http://www.cockroachesextermination.info/?f.

RESULTS:

-Cockroaches trapped in the toilets of:• houses with pit latrines:

98 parasites/ml

• houses with water system: 31 parasites/ml

-Pathogens isolated from external and internal surface of 98% of test cockroaches

Egypt Scenario

Ric_k. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/ric_k/3196975264/sizes/z/in/photostream/.

Thailand Scenario

“THE MAJORITY OF COCKROACHES FROM THE SAMUTPRAKARN PROVINCE OF THAILAND ARE CARRIERS OF PARASITIC ORGANISMS”

Pennapa Chamavit, Panupong Sahaisook, Nunthawadee Niamnuy, EXCLI Journal 2011

METHODS: 1) 920 cockroaches obtained in

Samutprakarn province of Thailand

• 18 open-air shopping markets in 5 districts, 1 subdistrict

• captured during feeding, natural habitat

2) Conducted wet smear/modified acid-fast bacilli staining identified pathogens

Corbie. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/crow/401136434/sizes/l/in/photostream/.

RESULTS:  -498/920 (54.1%) of the cockroaches harbored parasitic organisms

**Cockroaches isolated from these markets are carriers of several organisms:

• cause commonly found symptoms of illness such as diarrhea or bowel disorder

Thailand Scenario

Gusthed. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/bokage/5570904814/.

• > 50 species of synanthropic flies correlated with unsanitary conditions

• 21 species of filth flies transmit human gastrointestinal diseases

• ALL disseminate human pathogens in the environment

• breed in:• animal manure• human excrement• garbage• animal bedding• decaying organic matter

Flies as Mechanical Vectors

**350 fly species in 29 families are associated with food-borne diseases**

UNICEF Bangladesh. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/unicefbangladesh/6791300900/sizes/z/in/photostream/.

Characteristics:

• Musca domestica

-6-7 mm long, grey color

-marked by 4 dark longitudinal stripes

-breed in animal/human excrement or domestic organic waste

-land, breed, and feed on feces and human food

*RESPONSIBLE FOR: • Infantile diarrhea• Shigellosis diarrhea• Dysentery• Typhoid

Indian Housefly Scenario“Vector potential of houseflies (Musca domestica) in the transmission of Vibrio cholerae in India”

R. Fotedar, Acta Tropica, 2001

METHODS: 1) Small village 15 km away from

Delhi city outbreak of diarrhea

2) 150 houseflies captured with sterilized nets from animal pens, yards or houses

3) Collect stool samples from 50 patients within 24 hrs of illness, before anti-microbial

Praline 3001. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/praline3001/6672614287/sizes/l/in/photostream/ .

RESULTS:

-60% fly pools were positive for V. cholerae

-during outbreak: V. cholerae Ogawa T2 El Tor isolated from stools of patients suffering from diarrhoea

**Houseflies act as mechanical vectors of V. cholerae biotype El Tor, and aid in dissemination

Indian Housefly Scenario

Medicinssansfrontieres. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/medecinssansfrontieres/3085562538/sizes/z/in/photostream/.

Hospital Housefly Scenario

METHODS:

1) Collect Musca domestica from:• surgical ward (All India Institute of

Medical Sciences Hospital)• remote residential area 5 km away

as a control

2) A total of 113 flies were collected: • 65 from a surgical ward (test)• 48 from a residential area (comparison)

The housefly (Musca domestica) as a carrier of pathogenic microorganisms in a hospital environmentR. Fotedar, U. Banerjee,, S. Singh, Shriniwas and A. K. Verma, Journal of Hospital Infection, 1992

Gusthed. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/bokage/5521594305/sizes/l/in/photostream/.

Hospital Housefly Scenario

RESULTS:

-10 genera of bacteria isolated from the test group, 9 from control group

-the load of bacteria carried by the test group of flies was significantly more

**House flies therefore may act as vectors of potentially pathogenic bacteria in a hospital environment.

Cardiff Biossi Imaging. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/biosi-imaging/5517090693/sizes/l/in/photostream/.

• Musca sorbens

-resides in tropical areas

-breed in human feces

-feed on the secretion produced by eyes of people, especially children.

-6 mm long, grey

-2 dark stripes on the thorax. 

Characteristics:

*RESPONSIBLE FOR:• diarrheal diseases• transmission of the eye

disease trachoma 

• Chrysomya spp.

-worldwide distribution

-breeds in open latrines, garbage, animal excrement

-compact body, measuring 10 mm

-shiny blue or green

Characteristics:

*RESPONSIBLE FOR:• Diarrheal diseases• Dysentery• Intestinal worm eggs

 

Fly Life Cycle

MANTRA: “food, feces, flies, feces”

Sir Richard Feachem, KBE, FREng, DSc(Med), PhD, Director, The Global Health Group, Professor of Global Health UCSF

Four Stages:

1) Egg

2) Maggot

3) Pupa

4) Adult

Photograph by: Jim Kalisch, University of Nebraska - Lincoln Photograph by: Jerry F. Butler, University of Florida

Photograph by: Jim Kalisch, University of Nebraska – Lincoln

Mechanical Transmission Process

1) Dislodgement onto Food• electrostatic charge

2) Fecal Deposits• without changing infectivity• increased viscosity of feces

3) Airborne Particles• electrocution traps

• further spread of infectious particles

“feces enhances transmission of infectious agents much greater than that of any other substrate or medium”

Iwork2travel1. (Photographer). [Photograph]. Retrieved February 13, 2012, from: fhttp://www.flickr.com/photos/72457981@N00/353447863/sizes/l/in/photostream/.

“Super” Transmitters

Carry Pathogens on:

• spongy mouthparts

• body and leg hairs (setae)

• sticky substance• adherence during fly

resting periods

• sticky pads of the feet (tarsi)

PKMousie. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/pkmousie/2618446877/sizes/l/in/photostream/.

Jatin.muddu. (Photograher). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/jatinmuddu/2374306028/sizes/l/in/photostream/.

“Filthy Flies” – U of F insect pathologist, Dr. Jim Maruniak

http://www.youtube.com/watch?v=hMcf9C-iqJc

Results of Transmission

Major spread of bacterial enteric disease agents:1) Inflammation of the gut2) Diarrhea

And parasitic disease agents:

-Sarcocystis spp-Toxoplasma gondii -Isospora spp. -Giardia spp.-Entamoeba coli-Entamoeba histolytica/Entamoeba dispar-Endolimax nana -Pentatrichomonas hominis -Hammondia spp. -Cryptosporidium parvum

RachSilvester. (Photographer). [Photograph]. Retrieved fFebruary 13, 2012, from: http://www.flickr.com/photos/rachsilvester/6155801573/sizes/m/in/photostream/.

Rubber Slippers in Italy. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/rubber_slippers_in_italy/5997107603/sizes/z/in/photostream/.

Mechanically Transmitted GI Diseases• Salmonella• Typhoid• Bacillary Dysentery (Shigellosis)

Gusthead. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/bokage/5570316311/sizes/l/in/photostream/.

Signs and Symptoms

• Salmonella

Who is affected:

-elderly

-children

12 – 72 Hr Presentation (lasts 4 – 7 days):

-diarrhea•May require hospitalization•Can be fatal

-fever

-abdominal cramps

Can Develop:

-Reiter’s Syndrome

Treatment:

-antibioticsNIAID_Flickr. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/niaid/5613656967/.

Signs and Symptoms

• Typhoid - Salmonella Typhi

-un-industrialized nations• Asia• Africa• Latin America

Presentation:

-sustained fever (103° to 104° F)

-stomach pains

-headache

Result of :

-International travel

-Food/water contamination

Treatment:

-antibioticsSanofi Pasteur. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/sanofi-pasteur/5279772517/.

Signs and Symptoms

• Bacillary Dysentery - Shigellosis

Location:

-distributed worldwide

Presentation (lasts 5 - 7 days):

-diarrhea (bloody)

-fever

-stomach cramps

Can Develop:

-chronic arthritis

Treatment:

-antibiotics (Bactrim, Septra, Rocephin)

-anti-diarrheals (Imodium)

Nathan Reading. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/nathanreading/6808291881/.

Historical Significance

Wartime Effects

-WWI: strong correlation between fly density and the incidence of dysentery

-WWII battle of El Alamein: Axis losses due to dysentery

-Monumental nuisance during the Vietnam War

-Similar problems were encountered in the Persian Gulf War of 1991/subsequent humanitarian relief operations

-1992-93, relief forces in Somalia faced huge fly problems

-Operation Enduring Freedom and Operation Iraqi Freedom: camps placed in midst of unsecure population centers

http://www.defense.gov/multimedia/web_graphics/dod/DODc.jpg, http://www.defense.gov/multimedia/web_graphics/army/USARVc1.jpg, http://www.defense.gov/multimedia/web_graphics/navy/USNc.jpg: Courtesy of U.S. Dept of Defense

Sample Wartime Precautions

Disease Vector Ecology Profiles (DVEPs) and TECHNICAL GUIDE

NO. 30 - Filth FliesSignificance, Surveillance and Control

in Contingency Operations:

EMPHASIS:

-essential epidemiology-vector bionomics/behavior-pesticide resistance

 

Armed Forces Pest Management Board: 

Fly - Associated Diseases in Somalia: ENTERIC DISEASES

 AGENTS: a variety of organisms, primarily bacteria and protozoa. VECTOR TRANSMISSION: Fecal-oral

-house flies and other filth flies are implicated in amplifying outbreaks

• house fly, Musca domestica• filth flies, M. sorbens and M. biseta

-Cockroaches may also serve as mechanical vectors

Example

Primary Reduction Example“Reduction of transmission of shigellosis by control of houseflies (Musca domestica)”

Dani Cohen, et. al, The Lancet, 1991

Prospective Crossover Intervention Study

METHODS:

1) 2 military field bases several km apart in early summer, 1988

2) Implement and track progress of intensive fly control measures at one base, keep another as control

 

US Army Africa. (Photographer). [Phorograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/usarmyafrica/4325510666/sizes/l/in/photostream/.

RESULTS:

-after 11 weeks, fly counts were 64% lower on the bases exposed to fly control

 **Clinic visits for diarrheal diseases dropped by 42%:

• 85% for shigellosis (76% for antibodies to Shigella)

• 57% for antibodies to enterotoxigenic Escherichia coli

Primary Reduction Example

IFRC. (Photographer). [Photograph]. Retrieved February 13, 2012, from: http://www.flickr.com/photos/ifrc/6152296211/sizes/l/in/photostream/.

Preventative Measures

4 Main Goals:

1) reduction or elimination of fly breeding sites

2) reduction of sources that attract flies from other areas

3) prevention of contact between flies and disease-causing germs

4) protection of food, eating utensils and people from contact with flies.

• "zero fly" tarps• insecticide• new technology (WHO) shelter

Keiding J. The housefly—biology and control. Training and information guide (advanced level). Geneva, World Health Organization, 1986 (unpublished document WHO/VBC/ 86.937; available on request from Division of Control of Tropical Diseases, World Health Organization, 1211 Geneva 27, Switzerland).

PATH & WaterAid America

**Diarrheal disease is the 2nd killer of children

2 leading NGOs explore steps toward stopping deaths owing to diarrheal diseases internationally:

• adequate resources• effective implementation of available health• clean water• sanitation solutions

“Defeating a Global Killer: The Need for Action on Diarrheal Disease, a discussion of a growing global health crisis that receives little attention and what we can do about it”

(May, 2009). Defeating a Global Killer: The Need for Action on Diarrheal Disease . www.who.int/entity/pmnch/events/2009/InvitationDDevent.pdf. [Flyer]. February 13, 2012.