Eradication of Typhus Exanthematicus in Bosnia and Herzegovina

Typhus exanthematicus in Bosnia and Herzegovina held in endemic areas from which especially quickly began spread after . That year, in , one hundred epidemics of typhus fever appeared, with the highest incidence rate in Europe of . per ,. Directions of unique program in the world were to eradicate lice of the body, but also establish monitoring of the recidivism, Brill-Zinsser disease. Since , typhus exanthematicus (classical typhus) hasn’t appeared in Bosnia and Herzegovina, so epidemic typhus can considered as an eradicated communicable disease.


Introduction
Typhus exanthematicus, or epidemic typhus results from infection by Rickettsia prowazekii, gram-negative obligate intracellular bacterium ().Rickettsia prowazekii has been found worldwide.Foci of disease currently exist in many countries in Asia, Central and East Africa, and the mountainous regions of Mexico, Central and South America.War and famine can result in explosive outbreaks of the disease.Epidemic typhus is prototypical infection of the typhus group of disease.The pathology of this illness is representative of the entire category.The primary vector in person to person transmission is human body louse (Pediculus humanus corporis).Lice become infected when they feed on a new host, excreting R. prowazekii in the faeces.Transmission occurs when organisms in the louse discharge faeces or bite wound or other breaks in the skin ().The Rickettsia are also infectious by inhalation or contact with ZLATKO PUVAČIĆ ET AL.: ERADICATION OF TYPHUS EXANTHEMATICUS IN BOSNIA AND HERZEGOVINA the mucous membranes of the mouth and eyes ().Epidemic typhus has the most severe clinical presentation of the typhi infections.In severe disease cases, gangrene may occur and lead to loss of digits, limbs or other vascullitic process may also lead to CNS dysfunction.Second World War arrives to Bosnia and Herzegovina at a period of epidemic of classical typhus.Worsened living conditions due to war, result in rare epidemic outbreaks of classical typhus.However, with the end of the WW II, certain endemic hot-spots of classical typhus remain in Bosnia and Herzegovina, presenting a primary social and health problem.Elimination process of the disease was conducted in two directions.The first concentrated on fast eradication of hot-spots with the aim of reducing the reservoir of the typhus cause, with the second process monitoring and fighting the louse infection of humans.

Subjects and Methods
This research represents an epidemiological-clinical study of the trends of classical typhus cases in Bosnia and Herzegovina since .The study aims to answer whether classical typhus has been eradicated in full in Bosnia and Herzegovina, i.e. whether all hotspots have been eradicated, and louse infection in humans eliminated -the latter being the most important factor in transmission of this disease.With the aim of bringing scientific proof whether full eradication of classical typhus has been achieved in Bosnia and Herzegovina, extensive epidemiological and clinical data has been used, covering trends in numbers of cases of this severe infectious disease since .

TRENDS IN CLASSICAL TYPHUS CASES IN BOSNIA AND HERZEGOVINA
In year  there were , cases of typhus exanthematicus registered in Bosnia and Herzegovina, with  deceased.The rate of incidence was , per , and was the highest at that time in Europe.Even in , there were  cases of infection, with  deceased, a rate of incidence of  per .In spite of all efforts to get the classical typhus under control, this disease still represented a serious health problem in Bosnia and Herzegovina.Distribution of classical typhus cases between -, in topographical terms, was present in all regions.Only in , in Bosnia and Herzegovina there were over  registered epidemics of classical typhus with  to  cases each.In , epidemic of classical typhus occurred only in endemic areas, with smaller epidemic spots of at most  infected.Although in  there were  classical typhus cases registered in Bosnia and Herzegovina, the real figure was suspected to be higher (Graph ) .After , with a mild fall in the number of cases of classical typhus ( cases) which remained same in  ( cases), there is a rise in the number of infected in  (),  () and  ().(Graph ) Thanks to extensive efforts of health services in Bosnia and Herzegovina, there was a significant fall in the number of cases of classical typhus only in  (Graph ).Although there was a fall in the number of cases of classical typhus in this period, the overall total number of cases in Bosnia and Herzegovina formed  of all cases in Former Yugoslavia.The last clinically and diagnostically proven case of classical typhus infection was found in , in the village of Trabeusa, Travnik municipality (Puvačić).

ERADICATION OF CLASSICAL TYPHUS IN BOSNIA AND HERZEGOVINA
The health service had a priority role in conducting the classical typhus eradication strategy in Bosnia and Herzegovina ().Occurrence and spread of classical typhus cases in Bosnia and Herzegovina depended on three epidemiological factors: the number of reservoirs of classical typhus, the percentage of louse among the population, and the number of cases vulnerable to this infectious disease ().Despite a rise in the standard of hygiene, body louse among population wasn't decreasing below the epidemiological threshold, which is an important factor for prevention of risk of classical typhus spread.Because of this, and for the reason of eradication of louse in Bosnia and Herzegovina, ..people were checked for body and head louse in  -a unique preventative measure in prevention of classical typhus spread.Such preventative measure, aimed at preventing the spread of classical typhus through body louse, was not undertaken by any other country.Some   households were checked for louse infection, to find that , of households were infected with head lice, and , of households with body lice.Along with a widespread use of insecticides in all rural, as well as those urban areas where cases were found, the actual body louse infection was eradicated among  of the population.This affected the fact that -besides recurring cases of classical typhus in Bosnia and Herzegovina -the actual classical typhus transmission modes were interrupted.Since , when an active monitoring of Brill-Zinsser disease was established, until , there were  registered cases, representing every area with a higher percentage of classical typhus louse infection risk (,).At the time, an expert from USA, Murray, stationed in Bosnia and Herzegovina to help the health services differentiate cases of classical typhus from the Brill-Zinsser disease (,).On the basis of research, Murray and Gaon determined the world-recognised differentional diagnosis of primary versus recurdescent typhus, the Brill-Zinsser disease, therefore significantly helping this severe infectious disease be put under diagnostical and thereby epidemiological supervision (,) (Table ).In , Murray found  cases of Brill-Zinsser infection, whilst until end of , Gaon found .With the mentioned approach methods, widespread experience and operability, especially that of epidemiological services in Bosnia and Herzegovina, full eradication of classical typhus was achieved.Gaon introduced IFA (microimmunoflourescence) diagnostic method, which prescribes a classical typhus diagnosis for an antibody test result of < : (Ig) and >: (IgM), whilst in Brill Zinsser cases, the test result for IgG antibodies is normal.

Discussion
Last epidemic of classical typhus in Bosnia and Herzegovina was registered in , in the village of Podzvizd, municipality of Velika Kladuša.Unapparent and sub-clinical cases, especially in conditions of low louse infection, did not present an important factor in the transmission of this disease due to low and short-lasting recurrence.Occurrence of Brill-Zinsser disease during the most recent troubles in Bosnia and Herzegovina, did not result in occurrence of typhus among refugees.Those cases were most often older persons who had healed a classical typhus infection during childhood in WW II ().
ZLATKO PUVAČIĆ ET AL.: ERADICATION OF TYPHUS EXANTHEMATICUS IN BOSNIA AND HERZEGOVINA