Epidemiology

This report will discuss the recent growth of the infectious/communicable disease of paratyphoid and typhoid fever in underprivileged regions across India, together with its contributing factors, pathophysiology, signs, symptoms, and management.

Communicable / Infectious Disease That Occurred Globally

The twenty-first century’s onset was accompanied by growth in a range of wild and domesticated animal species acting as reservoirs/carriers of pathogens like bacteria, parasites, and viruses. Given the continuum of species of animals involved in the process and the pathogens’ typically complicated natural history, proper prevention, surveillance, and control/management of zoonotic infections poses a genuine public health challenge. Foodborne diseases, mad cow disease and other such newly developed zoonoses, as well as several agents of viral infections (like, Ebola, Nipah, monkeypox virus, Highly Pathogenic Asian Avian Influenza (H5N1), etc.) have seriously impacted public health, directly as well as indirectly. With continual changes to the environment, such occurrences are expected to increase in the future (Schlipkoter & Flahault, 2010). This paper will concentrate on paratyphoid and typhoid fever outbreak in underprivileged regions across India.

History of Typhoid and Para-typhoid

In the U.S., enteric fever occurs rarely. Out of the average 500 annual cases, approximately 60% are contracted by travelers to India, South America, or Mexico. There are three stages involved in paratyphoid fever: the initial stage, which is characterized by high body temperature; the toxic stage, which is accompanied by intestinal symptoms and abdominal pain; and lastly, the recovery period (from typhoid fever) which is quite protracted. For adults, the three stages may be spread out across a 4-to-6-week duration, whereas for children, the disease course may span only 10-15 days. In the second (i.e., toxic) stage, one to ten percent chances exist of intestinal hemorrhage or perforation (Frey, 2006). This disease has been identified as a well-known source of morbidity across the globe. Approximately 21.7 million typhoid cases occur globally, with the maximum burden borne by Central and South America, India, and the sub-Saharan African region. All the above regions are characterized by one similarity — poor sanitation and an increasing population. While very limited epidemiological information exists for projecting India’s actual situation as regards the disease, some population-based and hospital researches have revealed significant changes in typhoid fever occurrence (Banerjee, et al., 2014).

Pathophysiology

Salmonella (S.) paratyphi (A, B, C) and Salmonella typhi are sensitive to various antibiotics in vitro (external to the organism/individual). But, in vivo (internal) responses may not always be predicted with accuracy from information on external susceptibility, chiefly due to their primarily intracellular location in phagocytic cells. Since S. paratyphi and S. typhi are obligate human infections, no suitable animal models exist for testing treatment regimens. Generally, the murine model – S. typhimurium – has been employed in the assessment of paratyphoid and typhoid host defense systems and pathophysiology. However, treatment responses have not utilized this model (White, 2010).

Signs and Symptoms

Disease onset occurs gradually and is characterized by:

1. Constant high fever

1. Malaise (feeling ill)

1. Marked headache

1. Decrease in appetite

1. Spleen enlargement that may result in abdominal discomfort

1. Presence of a flat pink rash on the torso

1. Dry cough during the disease’s initial stage

1. Diarrhea or constipation– in case of adult patients, constipation will be more common.

The disease ranges in severity from mild (characterized by mild fever), to acute (accompanied by many complications).

Individuals who fail to get treated can continue having fever for several weeks/months; an alarming 20% of these patients may succumb to disease complications in this period. Mortality rate drops to around one percent with treatment. Paratyphoid symptoms are similar to those of typhoid; however, the former illness is typically a milder variant of the latter (Anon., n.d.)

Epidemiological Triangle

This is a model developed by scientists for understanding infections and the way they spread. This triangle has a total of three vertices/corners: agent, environment and host.

Agent – Paratyphoid and typhoid fever have been identified as key health problems in numerous developing nations. Typhoid fever’s etiologic agent, Salmonella typhi (Salmonella enterica serovar Typhi), accounts for more than 20 million and over 200,000 fatality occurrences globally per annum.

Host — After entry into human hosts via contaminated food/drinks, S. paratyphi and S. typhi have to circumvent other microorganisms that compete for mucosal adhesion and food, circumvent internal defense mechanisms in hosts, find an independent niche in mononuclear phagocytic systems, and live on and replicate. Lastly, they have to exit this host and get transmitted to another susceptible one.

Environment – Considering parallelism of the host, pathogen’s balanced environmental interactions can be helpful. The current situation in the Indonesian capital, Jakarta, can be described, with balanced host and pathogen factors’ environmental interactions leading to paratyphoid and typhoid endemicity (Ali, 2006).

Communicability and Prevalence

The communicable illness- typhoid — has several modes of transmission in India. Typhoid bacteria survive under unhygienic conditions. They spread largely through carriers and typhoid patients’ vomit and stools. These bacteria are then transmitted to food, water, and drinks via insects (such as house-flies), thereby contaminating food.

Salmonella enteritidis paratyphi A/B/C leads to paratyphoid. This infection is usually milder than typhoid. Hardly any typhoid patient will remain a chronic carrier, despite treatment. Most widely-occurring complications of the disease are intestinal perforation and bleeding. Polluted water is a key source. Raw vegetables that are cultivated on fields containing sewage spread infection as well. The bacteria are capable of surviving for months on end in water and soil, and undergo rapid growth in dairy products and milk. Unhygienic environmental conditions are to be chiefly held responsible for its prevalence (Anon., n.d.).

Spread of Typhoid

S. Typhi is able to survive only in the human body. People suffering from typhoid carry these bacteria within their intestinal tract and bloodstream. Additionally, few individuals (“carriers”) will recover from the disease whilst continuing to carry its bacteria. Carriers as well as sick individuals shed S. Typhi via feces). Typhoid fever may be contracted if a person eats food/drink handled by such a carrier, or if S. Typhi-contaminated sewage gets into drinking/domestic-use water. After such bacteria are consumed by the body, they will multiply and disperse in the person’s bloodstream. his/her body will react via high body temperature and other symptoms and signs (listed previously) (Fever, 2013).

Management of Typhoid

A sudden rise in typhoid cases or confirmation/suspicion of at least two cases within a period of 30 days in any new locality/village must be reported without delay, followed by an immediate investigation into the outbreak with the steps listed below (Kool, 2010):

1. Outbreak confirmation,

1. Creation of a modifiable case definition: i.e., individuals to be considered part of this outbreak should be defined

1. Identification of new cases and information-gathering

1. Line-listing (summary table containing basic information relating to outbreak time, place, and individual cases)

1. Description of collected data by time (symptom onset), place, and person

1. Establishment and reinforcement of communication channels among health facilities, management, and field officers, as well as with relevant national-level authorities

1. Communication of results to professionals and the community.

Status of Typhoid — 2020 Objectives

Delhi is the lone state in India to have included a vaccine for Typhoid fever in its child immunization schedule, beginning November 2004. Up to now, over two million kids have been administered typhoid vaccines, helped reduce multiple-drug-resistant typhoid cases in Delhi (Welfare, n.d.). One research work by McKinsey (Bhadoria, et al., 2012) revealed a considerable growth in adult/optional vaccine penetration (regular vaccines for typhoid and influenza as well as one-time shots (e.g., hepatitis A)). In 2020, market value is expected to reach $3.2-3.3 billion, growing at a yearly rate of 30-35%, beginning 2012. Very probably, as many as 5 ‘mega’ vaccines — anti-typhoid, anti-influenza, pneumococcal, hepatitis A, and HPV vaccines — costing more than 250 million dollars each, will dominate the market (accounting for 60% of it).

By the end of this year, every Indian state and Union Territory is expected to incorporate elimination of typhoid in their broad planning frameworks and health policies. By the end of next year, each state will be required to lower API (Annual Parasite Incidence) to below one for every thousand persons, and by the end of the year 2020, fifteen category 1 (i.e., elimination phase) states or Union Territories are projected to interrupt typhoid transmission, achieving the target of zero native cases and typhoid-related deaths. Further, it has been predicted that accelerated efforts of states like Karnataka, Maharashtra, and Gujarat, having relatively good health infrastructure and capacity, can usher quicker typhoid elimination — within a span of 2-3 years. According to the twelfth Five-Year Plan’s targets, India has to attain API<1 at district and state levels by next year, paving the way for elimination of typhoid in the years that follow (Welfare, 2016).

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