Encyclopedia Infectious Diseases in Africa

Encyclopedia
Of Infectious
Diseases in Africa

Introduction Author: Siti Zayana Binti Mistoh@Mastan

Editors: Raja Norzahirah Binti Raja Abdullah, Rachel Aris Anak Lislie Ebola

Virus Disease Author: Siti Zayana Binti Mistoh@Mastan

Vibro Cholera Disease Author: Raja Norzahirah Binti Raja Abdullah

Zika Virus Diseases Author: Rachel Aris Anak Lislie

Cover Design: Raja Norzahirah Binti Raja Abdullah, Rachel Aris Anak Lislie

This encyclopedia contains information obtained from authentic and highly
regarded sources. Reprinted material is quoted with permission, and
sources are indicated. A wide variety of references are listed. Reasonable
efforts have been made to publish reliable data and information, but the
authors and the publisher cannot assume responsibility for the validity of all
materials or for the consequences of their use. Neither this book nor any part
may be reproduced or transmitted in any form or by any means, electronic or
mechanical, including photocopying, microfilming, and recording, or by any
information storage or retrieval system, without prior permission in writing
from the publisher.

First Edition
Published in 2022

This Encyclopedia is dedicated to
Dr, Chiam Sun May, Our Biology

Lecturer.

CONTENTS

Whatis InfectiousDiseases? 1
EbolaVirusDisease (EVD) 3
VibrioCholeraDisease 7
ZikaVirusDisease 11
OtherInfectiousDiseases 15
References 16

What is
Infectious
Disease?

Infectious diseases are
diseases caused by
organisms such as

bacteria, viruses, fungi,
and parasites

They are usually
Harmless and useful as

they live in or on our
body. However, under
certain conditions, these
microbiology can cause

illness

Some infections can be
transmitted from person to
person. Some are transmitted
from insects and other animals. It

can then catch others by
consuming contaminated food
and water, and by being exposed

to living organisms in the
environment.

Let us discover
some of the

infectious diseases
in Africa.

1

Want to know
more about

infectious diseases
in Africa?

Come and
join our trip!

2

Ebola Virus Disease (EVD)

Ebola virus disease (EVD) was discovered in
Central Africa in 1976 (Kavey, 2020). Two
consecutive fatal haemorrhagic fever (Mader,
2022) have proven to be one of the most deadly
viral diseases. The first outbreak occurred in
Zaire(he Democratic Republic of the Congo)
(Crawford, 2017), in a village near the Ebola
River. Therefore, the virus was named after the
river. A second outbreak occurred in South
Sudan about 850 km away.

The scientists found that the first two
outbreaks were caused by two
genetically different viruses: the Zaire
Ebolavirus and the Sudanvirus. It was
later concluded that the virus
originated from two different sources
and spread independently between
people in each affected area (Biology,
2013).

Only Ebola, Sudan, Taï Forest, and Types of Ebola Virus:
Bundibugyo viruses have caused · Ebola virus (species Zaire ebolavirus)
disease in humans (Feldmann et al., · Sudan virus (species Sudan ebolavirus)
1994). Reston virus can cause disease · Taï Forest virus (species Taï Forest
in non-human primates and pigs, but ebolavirus)
there are no cases in humans · Bundibugyo virus (species Bundibugyo
(Taniguchi, 2011).Bombali virus was ebolavirus)
first discovered in bats in 2018, and · Reston virus (species Reston ebolavirus)
experts don't yet know if it causes · Bombali virus (species Bombali ebolavirus)
disease in animals or humans.

Causes

Ebola virus has been found in
African monkeys,
chimpanzees, and other non-
human primates (Baseler et al.,
2017). Mild Ebola has been
found in pigs in the
Philippines (Crawford, 2017).

3

Structure of Ebola Virus

A virus is a microorganism that can replicate without a
host and subsequently infiltrate different kinds of
organisms (Reece, 2020), so viruses exist everywhere.
There are tonnes of viruses in the earth, and they may be
found in almost every habitat.

All viruses have attachment proteins
(glycoproteins) (Reece, 2020). Ebola is
infectious because its long, filament-shaped
virus particle is encapsulated fully by these
glycoproteins.
This virus is a member of the Filovirus family
(Reece, 2020), and its structure is like a
length of thread.

Ebola viruses are typically 80 nm
in diameter and 14000 nm in
length (Baylor College of
Medicine, n.d.)

Once the glycoprotein finds and The virus's genetic contents
attaches to healthy cells, the are released into the cells
Ebola virus can penetrate the
FUN FACT ! cells and immune system and
EBOLA replicate itself (Aryal, 2018).
VIRUS IS
NOT they use a combination of host
and virus-encoded enzymes
REPLICATED along with the host cell structure
BY ANY TYPE to produce multiple copies of
the virus (Basler et al., 2019).
OF CELL
DIVISION




New copies of virus 4
released to the system

Method of Transmission

from animals to humans Fun Fact!

Blood It is not known that the Ebola
virus is transmitted through food.
Eating killing or infected animals can However, the Ebola virus can
spread the virus. Operationalists also spread by handling and eating
captured viruses as part of the research the meat of wild animals infected
on infected animals. with Ebola and hunted wild
animals (Centers for Disease
Control and Prevention, n.d.).

Excrement Semen from recently
recovered patients
Tourists in certain
African caves and some Contaminated
underground miners are objects such as
infected with the Ebola needles, clothes,
virus, probably through
contact with infected bat and mask
feces and urine
(Crawford, 2017).

Bodily fluids from an
infected person

People infected with Ebola or Marburg virus
usually do not spread until symptoms appear
(Beltz, 2017).

Human to human

5

Symptoms Fun Fact!

The initial signs and symptoms are: Incubation Period: 2-21 days
• Fever On the eight-day, people
• Severe headache infected with Ebola will
• Joint and muscle pain usually show the symptomps
• Chills Signs and symptoms usually
• Weakness begin suddenly within 5-10
Symptoms become more severe, like: days of infection with the
• Nausea and Vomiting Ebola virus (Baseler et al.,
• Diarrhoea (may contain blood) 2017).
• Red eyes
• Throat pain How Is Ebola

Prevention Treated?

Researchers are working on Ebola,
but there is no cure for Ebola.
Doctors treat the symptoms of Ebola
as follows (Baseler et al., 2017):
·Fluids and electrolytes
·Oxygen
·Blood pressure medication
·Blood transfusions
·Treatment for other infections

Follow the instructions of the health authorities
If you suspected someone in your family or society
has Ebola, encourage him to get immediate
treatment and also provide him your support.
If you need to care for or have direct contact with
Ebola patient use personal protective equipment
(PPE)
Wash your hands properly after visiting someone in a
hospital or any other place (Centers for Disease
Control and Prevention, n.d.)
Refrain from eating bushmeat.

6

Vibrio Cholera
Disease

INTRODUCTION

Cholera is a disease that infects intestine
which lead to diarrheal illness. The
disease is caused by the bacteria Vibrio
Cholera that produces toxin which lead
to diarrhea and even death. Based on the
statistics, reported cholera cases is
estimated to reach 2.9 million and
95,000 deaths globally in every year.
Cholera disease often occurred in
developing countries including Africa
due to the poor sanitation, inadequate
hygiene and much more.

HISTORY

Cholera pandemics that originated from India
in 1817 had occurred seven times during the
past 200 years. The first cholera pandemic had
killed hundreds of thousands of Indians. The
disease spread to many places including
Southeast Asia, The Middle East, Europe and
Eastern Africa through the trade
routes(History.com Editors, 2017).

Africa countries that were
affected by the cholera outbreaks

The first pandemic

.The first cholera disease detected in Africa

was in 1971. Since then, Africa becomes the

most affected country due to poor sanitation

and water supply infrastructure (Kariuki,

2017). Cholera is a persistent cause of

mortality in Africa. 7

Vibrio Cholerae

.The bacterial pathogen Vibrio cholerae Vibrio Cholerae
is responsible for the disease cholera, 0139
which affects many impoverished
countries and places with poor Vibrio Cholerae
sanitation, causing around 2.9 million 01
cases and 95 000 fatalities each year.

Vibrio cholerae is a Gram-negative
bacillus with a curved shape. It has a
single polar flagellum that is actively
motile. Vibrios are anaerobic organisms
that favour alkaline, high-salt
conditions.

Types of Vibrio Cholerae

V. cholerae has multiple serogroups, but
only two of them – O1 and O139 – cause
outbreaks. All recent epidemics have been
caused by V. cholerae O1. V. cholerae
O139, initially discovered in Bangladesh in
1992, has previously caused epidemics
but is now only found in occasional
instances.

Where to find Vibrio
Cholerae?

Marine and brackish waters are the natural

environment for the etiologic agents of cholera,

Vibrio cholerae serogroup O1 or O139.

Although Vibrio cholerae has no known animal

hosts, the bacteria can easily attach

themselves to the chitin-containing shells of

crabs, shrimps, and other shellfish, which can

be a source of human illnesses if consumed

uncooked or undercooked.

V. cholerae is transmitted to humans from its

aquatic environment by contaminated water

and food. (Carrillo-Lopez et al., 2011) 8

HOW DOES THE
CHOLERA DISEASE

SPREADS?

Basically, cholera disease spreads
through the faecal-oral route. There are

many factors that cause the
transmission of the bacteria. Let's take a

look together!

Cholera is contracted by
consuming foods and water
that have been contaminated
by an infected person's faeces.
In areas with poor sewage
treatment, the Cholera
bacteria spread quickly.

Poor sanitary Contaminated Food Cholera cases are also
conditions and water reported in industrialized
nations. Consuming shellfish
CAUSES OF from waters that are known to
CHOLERA DISEASE harbour the cholera bacteria
can cause the disease.

The chance to get infected by
cholera disease increases
when people live or visit the
endemic area such as in Africa

Raw or undercooked Extra caution must be taken
shellfish such as keeping hands clean,
consuming clean water and
foods

Living or visiting DID YOU KNOW?
an endemic area
Cholera toxin activates the key
Type O blood signalling molecule stronger in
people with blood Type O than
9 Type A which lead to excretion
of electrolytes and water that

caused severe diarrhoea.

DID YOU KNOW? SYMPTOMS OF
CHOLERA DISEASE
An infected person can
detect the presence of Nausea & Dehydration Diarrhea
Vomitting
Vibrio Cholerae bacteria

through a stool sample or a
rectal swab and tested in a

laboratory

Rectal swab Excessive thirst Sleepiness & Muscle cramp

HOW TO PREVENT Lethargy
CHOLERA DISEASE?
DID YOU KNOW?
Wash hands with soap and
water frequently According to the WHO,

Drink safe water Vibrio Cholerae takes

Cook the foods completely between 12 hours and five
before eating days to incubate in the body

Avoid eating raw foods such before generating
as sushi symptoms.

Takes vaccine before travelling Symptoms usually develop
to an endemic country two to three days after

contact with the bacteria,
according to the CDC.

There are some effective antibiotics Can antibiotic
kill theVibrio
that can kill the Vibrio Cholerae such
Cholerae?
as doxycycline, azithromycin and
tetramycin. Now, doxycyline is used as
the drug to treat the disease
However, the bacteria become and killed the bacteria
resistant to some antibiotics. In the
last 10 years, Vibrio Cholerae had (Kariuki, 2017) 10
became resistant to nalidixic acid,
trimethoprim, sulphamethoxazole,
streptomycin and furazolidone. The
antibiotics are no longer used to treat
the disease.

HISTORY Zika Virus
Disease
Zika virus disease is a mosquito-
borne disease (Aedes aegypti
and Aedes albopictus) that was
first identified in Uganda in
1947 in monkeys (rhesus
sentinel). It was later identified
in humans in 1952 in Uganda
and the United Republic of
Tanzania (World Health
Organization, 2018).

DID YOU KNOw?

You can differentiate aedes
aegypti and aedes albopictus just
by looking at the white lines on
their head.

Aedes aegypti Aedes albopictus

Zika virus Zika virus Zika virus
first causes an causes an
outbreak on outbreak in
identified
in Uganda. the Yap Brazil.
Islands.

1947 1952 2007 2013 - 2014 - 2016
2014 2015

Zika virus is Zika virus WHO declares
first causes an Zika virus to be
outbreak in a public health
reported in emergency of
11 a human. French
Polynesia. international
concern.

HOW DOES ZIKA
VIRUS INFECT OUR
CELLS?

Zika virus particles need to enter human's body cell in other
to replicate and make new viruses. Inside the human body
cell, the RNA genome of the virus is released into the
cytoplasm of the cell. Inside of the cell, RNA molecule is
translated by enzymes in the cell to make long protein which
will chopped up into smaller protein. Viral proteins and
copies of the RNA genome assemble at the surface of the
endoplasmic reticulum (ER). New viral particles bud off into
the ER's interior, bringing with them a small patch of ER
membrane.
Following that, the particles
pass via the Golgi apparatus,
where they are further
processed before being
released at the cell surface.
Virus particles released into
the environment can infect
neighbouring cells, causing
the infection cycle to
continue.

12

THE STRUCTURE OF

ZIKA VIRUS

Zika viruses are the members of the
Flavivirus genus of the Flaviviridae
family. The Zika genome is roughly
11 kb length and comprises of a
single-stranded, positive-sense RNA
molecule that encodes a polyprotein
that is proteolytically broken into
structural and non-structural
proteins. A capsid (C) protein,

a glycoprotein precursor (preM) that is divided into the pr and M proteins,
and an envelope (E) protein are among the structural proteins. The NS1,
NS2A, NS2B, NS3, NS4A, NS4B, and NS5 proteins are non-structural proteins
(Virus Pathogen Database and Analysis Resource, 2015).

THROUGH MOSQUITO BITES METHODS OF

Zika virus is transmitted to

people primarily through TRANSMISSION
the bite of an infected

Aedes species mosquito FROM MOTHER TO CHILD THROUGH BLOOD
(Ae. aegypti and Ae.
albopictus). A mosquito A pregnant woman TRANSFUSION

gets infected with a virus can pass Zika virus to The blood
when it bites an infected her fetus during from the
person during the period
of time when the virus can pregnancy or around blood donor
time of birth. Zika is who was

be found in the person’s the cause of infected with
blood, typically only microcephaly and Zika virus will
through the first week of other severe fetal
infection. enter the
brain defects. recipient's

bloodstream.

THROUGH SEX DID YOU KNOW?

Zika can be passed Microcephaly is a condition where a baby's
through sex from a head is much smaller than expected. Children who
person who has Zika suffered from microcephaly have normal intelligence
to his or her partners. and have normal developmental milestones, but their
This is because Zika heads will always be smaller than normal children for
stays in the semen their age and sex.
and vaginal fluids of

people who have

Zika.

Normal head size Microcephaly 13

SYMPTOMS OF ZIKA HOW TO TREAT ZIKA
VIRUS DISEASE VIRUS DISEASE?

Fever Treat the symptoms.

Get plenty of rest.
Drink fluids to prevent
Joint pain dehydration.

Take medicine such as
acetaminophen to reduce fever
Rash and pain.

Do not take aspirin and other
Headache non-steroidal anti-inflammatory

drugs (NSAIDS) until Zika can be
ruled out to reduce the risk of
Conjunctivitis bleeding.
(red eyes) If you are taking medicine for

another medical condition, talk to
your healthcare provider before
Muscle
taking additional medication.
pain

METHODS OF

PREVENTION

One of the best way to
prevent Zika virus disease is
to avoid mosquito bites
(Centers for Disease Control
and Prevention). To make
that happen we need to use
long pants and long sleeved
clothes.

14

OTHER INFECTIOUS

DISEASES

African Trypanosomiasis
(Sleeping Sickness)

A person will get African Trypanosomiasis if they
are bitten by a tsetse fly infected with the
Trypanosoma brucei rhodesiense or
Trypanosoma brucei gambiense parasite
respectively. The common symptoms of African
Trypanosomiasis are fever, severe headaches,
irritability, extreme fatigue, swollen lymph nodes,
and aching muscles and joints.

Acquired immunodeficiency
syndrome (AIDS)

AIDS is a disease caused by HIV (human


immunodeficiency virus) that damages the cell
in our immune system and lessen the ability to
fight infection and disease. HIV is found in the

body fluids of an infected person which is
semen, vaginal and anal fluids, blood and
breast milk. There are no cure for this disease
but there are an effective drug treatment that

enable infected person to live longer.

Tuberculosis (TB) 15

Tuberculosis (TB) is caused by a bacterium called
Mycobacterium tuberculosis. The bacteria
usually attack the lungs, but TB bacteria can
attack any part of the body such as the kidney,
spine, and brain. This bacteria was are spread
through the air from one person to another.
Person who was nearby will get infected when
infected person are talking or coughing. The
symptoms of this disease is a bad cough that lasts
3 weeks or longer, pain in the chest, coughing up
blood, fatigue, weight loss, no appetite, fever,
chills and sweating at night.

References

Aryal, S. (2018, June 23). Replication of Ebola Virus.
Microbiology Info.Com. Retrieved March 6, 2022, from
https://microbiologyinfo.com/replication-of-ebola-virus/

Baseler, L., Chertow, D. S., Johnson, K. M., Feldmann, H., &
Morens, D. M. (2017). The Pathogenesis of Ebola Virus
Disease. Annual Review of Pathology: Mechanisms of
Disease, 12(1), 387–418. https://doi.org/10.1146/annurev-
pathol-052016-100506

Basler, C. F., Krogan, N. J., Leung, D. W., & Amarasinghe, G.
K. (2019). Virus and host interactions critical for filoviral RNA
synthesis as therapeutic targets. Antiviral Research, 162,
90–100. https://doi.org/10.1016/j.antiviral.2018.12.006

Baylor College of Medicine. (n.d.). Ebola Virus. Retrieved
March 6, 2022, from
https://www.bcm.edu/departments/molecular-virology-and-
microbiology/emerging-infections-and-biodefense/specific-
agents/ebola-virus

Beltz, L. A. (2017). Bats and Human Health: Ebola, SARS,
Rabies and Beyond (1st ed.). Wiley-Blackwell.
Biology. (2013). McGraw Hil.

CDC - African Trypanosomiasis - General Information - East

African Trypanosomiasis FAQs. (2022).

https://www.cdc.gov/parasites/sleepingsickness/gen_info/fa

qs.html

Centers for Disease Control and Prevention. (n.d.). Ebola
(Ebola Virus Disease) | CDC. Retrieved March 6, 2022, from
https://www.cdc.gov/vhf/ebola/index.html

Centers for Disease Control and Prevention. (2022). Sources
of Infection & Risk Factors.
https://www.cdc.gov/cholera/infection-sources.html

Cholera. (2019). WHO | Regional Office for Africa.
https://www.afro.who.int/health-topics/cholera‌

16

‌Cholera - Symptoms and causes. (2022). Mayo Clinic;
https://www.mayoclinic.org/diseases-
conditions/cholera/symptoms-causes/syc-20355287

Crawford, D. H. (2017). Ebola: Profile of a Killer Virus
(Illustrated ed.). Oxford University Press.

Epelboin, S., Dulioust, E., Epelboin, L., Benachi, A., Merlet,

F., & Patrat, C. (2017). Zika virus and reproduction: facts,

questions and current management. Human Reproduction

Update, 23(6), 629–645.

https://doi.org/10.1093/humupd/dmx024

Feldmann, H., Nichol, S. T., Klenk, H. D., Peters, C. J., &

Sanchez, A. (1994). Characterization of Filoviruses Based on

Differences in Structure and Antigenicity of the Virion

Glycoprotein. Virology, 199(2), 469–473.

https://doi.org/10.1006/viro.1994.1147

History of Zika Virus: Outbreaks and Vaccine Timeline.

(2016). Mayo Clinic.

https://www.mayoclinic.org/coronavirus-covid-19/history-

disease-outbreaks-vaccine-timeline/zika-virus

Kariuki, S. (2017, July 24). Kenya’s cholera outbreak
highlights fears about antibiotic resistance. The
Conversation. https://theconversation.com/kenyas-cholera-
outbreak-highlights-fears-about-antibiotic-resistance-81274

Kavey, R. (2020). Viral Pandemics (1st ed.). Routledge.

Khan Academy. (2022). Khanacademy.org.

https://www.khanacademy.org/science/biology/biology-of-

viruses/virus-biology/a/what-is-zika-virus

Mader, S. (2022). Concepts of Biology W/ Connect Plus (2nd
Edition) (2nd ed.). McGraw Hill.

Mader, S. (2022). Concepts of Biology W/ Connect Plus (2nd
Edition) (2nd ed.). McGraw Hill.

NHS Choices. (2022). Overview - HIV and AIDS.
https://www.nhs.uk/conditions/hiv-and-
aids/#:~:text=AIDS%20(acquired%20immune%20deficiency%
20syndrome,another%2C%20the%20HIV%20virus%20can.

Reece, T. J. B. (2020). Campbell Biology (12th ed.). Pearson.
Taniguchi, S. (2011). Reston Ebolavirus Antibodies in Bats,
the Philippines. Emerging Infectious Diseases.
https://doi.org/10.3201/eid1708.101693

Symptoms. (2014, November 5). CDC.
https://www.cdc.gov/zika/symptoms/symptoms.html

Treatment. (2014, November 5). CDC.

https://www.cdc.gov/zika/symptoms/treatment.html

verywellhealth. (2012). Cholera: Causes and Risk Factors.
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causes-and-risk-factors-4160848

Virus Pathogen Database and Analysis Resource (ViPR) -
Flaviviridae -. (2015). Viprbrc.org.
https://www.viprbrc.org/brc/staticContent.spg?
decorator=flavi&type=About&subtype=ZIKV#:~:text=Zika%2
0virions%20are%20comprised%20of,proteins%20in%20icosa
hedral%2Dlike%20symmetry.

World. (2016, February 7). The history of zika virus. Who.int;
World Health Organization: WHO.https://www.who.int/news-
room/feature-stories/detail/the-history-of-zika-virus

World. (2018, July 20). Zika virus. Who.int; World Health
Organization: WHO. https://www.who.int/news-room/fact-
sheets/detail/zika-
virus#:~:text=Zika%20virus%20disease%20is%20caused,last
%20for%202%E2%80%937%20days.
Zika Transmission. (2014, November 5). CDC.
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methods.html#:~:text=Through%20mosquito%20bites,sprea
d%20dengue%20and%20chikungunya%20viruses.

SCES1104 FUNDAMENTALS OF BIOLOGY II



Encyclopedia
Of Infectious Diseases

in Africa

For all these infectious diseases,
the goal is to eventually get rid
of them. And to do that we need
to invent new tools, but nobody
was doing that because there
was no money to buy on behalf
of the poorest, even the existing

tools.
-Bill Gates-

AUTHOR:
RACHEL ARIS ANAK LISLIE
RAJA NORZAHIRAH BT RAJA ABDULLAH
SITI ZAYANA BINTI MISTOH@MASTAN